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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pump apparatus, and more particularly to a gerotor-type gear pump. The pump of this invention is particularly useful in applications such as transmissions, hydraulic pumps, oil pumps and the like used in the automotive and other industries.
2. Background Information
The term "Gerotor" was first used by Myron F. Hill to describe a geometry for mutually generative rotors in pumps and gears. Gerotor-type gear pumps comprise a gerotor set including an externally toothed inner gear-like rotor and an internally toothed outer rotor disposed about respective eccentric axes in an interior chamber of a housing. The rotating, meshed rotor teeth define a continuous series of expanding and contracting cavities in the chamber. The expanding cavities take fluid in from an inlet port and the contracting cavities force fluid out through an outlet port.
Although gerotor-type gear pumps are well known, existing devices and methods have significant limitations and shortcomings. Of particular importance are limitations concerning simplicity of design, flow control, and pump efficiency.
Examples of relevant apparatus and methods are disclosed in U.S. Pat. No. 2,509,321 to Topanelian, Jr. for a rotary fluid unit for take-off under variable control, in U.S. Pat. No. 4,420,292 to Lutz for bi-directional internal/external gear pump with advanced porting, and in U.S. Pat. No. 4,887,956 to Child for variable output oil pump.
Despite the need in the art for a gerotor-type gear pump which overcomes the disadvantages, shortcomings and limitations of the prior art, none insofar as is known has been developed or proposed.
Accordingly, it is an object of the present invention to provide a gerotor-type gear pump which utilizes variable axially oriented porting and variable flow control. It is a further object of this invention to provide an axially ported, variable flow gerotor-type gear pump which is automatically adjustable, highly efficient, has a simple economical design, and which overcomes the limitations and shortcomings of the prior art.
SUMMARY OF THE INVENTION
The apparatus of the present invention provides an axially ported, manually or automatically controlled, variable flow gerotor-type gear pump. The pump is useful in a variety of applications including automotive transmissions, power steering pumps and oil pumps.
In a basic embodiment the invention provides a gerotor pump, comprising a body having an annular interiorly disposed channel, a port plate manually rotatably connected to the body and covering the channel, the port plate having an inlet port and an outlet port communicatively connected to the channel, an outer rotor disposed in the channel, an inner rotor rotatably and centrally disposed with respect to the outer rotor and having a drive shaft axially connected thereto, and means to rotate the port plate.
In a first preferred embodiment, the invention provides an axially ported, manually adjustable variable volume gerotor fluid pump, comprising:
(a) a body having an annular interiorly disposed channel;
(b) a port plate coupled to the body and covering the channel, the port plate having axially oriented fluid inlet and outlet ports communicatively connected to the channel;
(c) a gerotor set including an outer rotor disposed in the channel and an inner rotor rotatably and centrally disposed with respect to the outer rotor and having a drive shaft axially connected thereto with a threaded end extending a predetermined distance through the port plate; and
(d) at least one nut coupled to the shaft threaded end, the nut being for holding the port plate to the body with a predetermined degree of tension whereby the port plate is manually rotatable with respect to the body.
In a second predetermined embodiment, the invention provides an axially ported, automatically controlled variable volume gerotor pump, comprising:
(a) a first body having an annular interiorly disposed channel;
(b) a port plate rotatably coupled to the first body and covering the channel, the port plate having axially oriented fluid inlet and outlet ports communicatively connected to the channel;
(c) a second body rotatably coupled to the port plate, the second body further being fixed to the first body so that the port plate is disposed between the first body and the second body, the second body having fluid inlet and outlet apertures communicatively connected to the port plate inlet and outlet ports, respectively, and further having an annular control groove;
(d) a gerotor set including an outer rotor disposed in the first body channel and an inner rotor rotatably and centrally disposed with respect to the outer rotor and having a drive shaft axially connected thereto; and
(e) a fluid volume control mechanism including:
(i) a spring connected to the body and to the port plate, the spring providing a predetermined rotational force to the port plate in a first direction;
(ii) a piston providing a predetermined rotational force to the port plate in a second direction, opposite the first direction, the piston being connected to an interiorly facing end of the port plate and being movably disposed in the second body control groove, and
(iii) a fluid channel connected to the outlet port and to a predetermined point on the interiorly facing end of the port plate, adjacent the piston, the fluid channel directing fluid from the outlet port into the second body control groove to drive the piston in the control groove.
The features, benefits and objects of this invention will become clear to those skilled in the art by reference to the following description, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a gear pump in accordance with the present invention.
FIG. 2 is a perspective view of the opposite end of the pump shown in FIG. 1.
FIG. 3 is a view of the gerotor set of the pump.
FIG. 4 is a view of the ports of the pump.
FIG. 5 is a diagrammatic view of the porting arrangement of the pump of this invention, shown with its input/output ports adjusted for maximum fluid flow.
FIG. 6 is a diagrammatic view of the porting arrangement shown with its input/output ports adjusted for, near zero, minimum flow.
FIG. 7 is a side view of an embodiment of a pump assembly for an automotive engine oil pump and having a port plate control mechanism.
FIG. 8 is a side view of the lower housing of the pump assembly shown in FIG. 7.
FIG. 9 is a top view of the lower housing.
FIG. 10 is a side view of the upper housing of the pump assembly shown in FIG. 7.
FIG. 11 is a top view of the upper housing.
FIG. 12 is a side view of an inner rotor of the pump assembly shown in FIG. 7.
FIG. 13 is a top view of the combined inner and outer rotors of the pump assembly.
FIG. 14 is a side view of a port plate for use with the pump assembly.
FIG. 15 is a top view of the port plate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an axially ported, variable flow gerotor-type gear pump. Manually and automatically controlled pump embodiments are provided The pump is useful in a variety of applications including automotive transmissions, power steering pumps and oil pumps.
Referring to FIGS. 1 and 2, one embodiment of the gear pump apparatus 10 of the present invention basically comprises a pump body 11, a pump cover or plate 12 and a longitudinally oriented shaft 13. These members are constructed of high strength rigid metallic substances such as stainless steel or a similar material.
The pump body 11 includes a rectangular, somewhat thin mounting flange 17 which has several apertures for mounting to related apparatus. On one side of the mounting flange 17 is located a cylindrical bearing housing 18 and on the opposite side is located a cylindrical gear housing 19. The bearing housing 18 has an internal cavity which houses bearing means for rotatably retaining the shaft 13. The gear housing 19 also has a hollow cavity which houses gears as described further below.
The pump cover or port plate 12 is a cylindrical structure which is connected to the front face of the pump body gear housing 19 via a manually releasable retaining assembly 20 which is linked to a threaded terminal portion 14 of the shaft 13 shown extending longitudinally and concentrically with respect to and through the cover 12. The pump cover 12 contains ports as described below which are communicatively connected to connectors 21 and 22. The connectors 21 and 22 provide a means of communicatively connecting hose or tubing (not shown) coupled to related apparatus. The retaining assembly 20 permits rotational movement of the cover 12 with respect to the body 11 when it is loosened and locks the cover 12 in its adjusted position when tightened. The retaining assembly 20 comprises an outer hex nut 24, an inner nut 25 and a plurality of flat washers 26a-c. The washers 26 provide proper spacing of the nuts 25 and 24 on the shaft end 14 and further provide an increased area for frictionally engaging the surface of the cover 12. The inner nut 25 has a threaded interior which is complementary to the shaft threads 14. The inner nut 25 is the primary tightening means for the assembly 20. In a preferred mode of operation, the inner nut 25 is tightened to a level whereby the cover plate 12 is held closely to the body 11. In this position, the cover 12 is substantially leak-free, but is also able to be manually rotated with respect to the body 11. The outer nut 24 functions to lock the inner nut 25 in place, notwithstanding vibration and other forces, during operation.
The shaft 13 extends axially and concentrically through the body member 11 and the cover member 12. The shaft 13 is rotatable, but longitudinally and laterally fixed in place, primarily via beating means (not shown) disposed in the bearing housing 18. A pulley 23 or other connective structure is connected to a first end of the shaft 13 and provides a rotational driving force thereto. The opposite end of the shaft 13 extends through to the exterior of the cover 12 for coupling to the retaining assembly 20.
Referring to FIGS. 3 and 4, the body and cover 11 and 12 mate at respective flat circular faces 31 and 35. The cover 12 is rotatable with respect to the body 11 to quickly and easily adjust fluid flow upon loosening the retaining assembly 20. A ring shaped outer rotor or ring gear 28 having a plurality of internally oriented teeth or lobes 33 and a circular outer circumferential surface is disposed in the annular chamber or inner cavity 30 of the body 11. An inner rotor 27, sometimes referred to as a star or pinion gear, is also disposed in the cavity 30, centrally with respect to the outer rotor 28. The inner rotor 27 is preferably connected to the shaft 13 via a key or other means (not shown). The inner rotor 27 has a plurality of exteriorly oriented teeth or lobes 32. The inner rotor 27 has one less tooth 32 than the number of teeth 33 in the outer rotor 28. The teeth 33 and 34 generally mesh and are separated in predetermined regions of the rotors 27 and 28 to define cavities or teeth spaces 29.
As is best shown in FIG. 4, the cover or port plate 12 is a disc-shaped structure with spaced, elongated, symmetrical groove shaped inlet and outlet ports 37 and 38. Each port 37 and 38 is communicatively connected to an access aperture 39 and 40, respectively, which is open to the outside thee of the plate 12. The access apertures 39 and 40 function as inlet/outlet means for fluid coming into and out of the chamber 30 as is described further below. The ports 37 and 38 provide a means of adjusting the rate of fluid flow, also as described in detail below.
Importantly, the central axis of the inner and outer rotors 27 and 28 are eccentric with respect to one another. The inner rotor 27 is concentric with respect to the shaft 13, whereas the central axis of the outer rotor 28 (and hence the chamber 30), although parallel to the axis of the inner rotor 27 and shaft 13, is offset from such axis by a slight distance; in this embodiment of the apparatus 10, approximately one half the height of a tooth on a rotor 27 or 28 or on the order of 0.254 inches (1.0 cm.). The inner rotor 27 rotates with the shaft 13, in a clockwise direction for example. The outer rotor 28 is rotatable within the chamber 30 and driven in the same direction by the inner rotor 27.
Referring also to FIGS. 5 and 6, due to the eccentricity of the rotors 27 and 28, at an initial point the rotor teeth 32 and 33 proximate a first side 46 of the chamber 30 are in full mesh while the teeth 32 and 33 on the opposite, second side 47 are completely out of mesh, thereby forming two nearly 180 degree regions of successively increasing sized tooth spaces or cavities 29 centered about sides 48 and 49. Upon rotation of the inner rotor 27, the cavities 29 of the region centered about side 48 successively expand while the cavities 29 of the region centered about side 49 contract. By positioning the ports 37 and 38 as shown in FIG. 5, fluid such as transmission or another hydraulic fluid, or oil, for example, is sucked into aperture 39 and forced out of aperture 40 at a maximum rate due to the exposure of port 37 to the full length of the region of cavity expansion and to the exposure of port 38 to the full length of the region of cavity contraction. In contrast, by aligning the ports 37 and 38 as shown in FIG. 6, fluid is input to aperture 39 and output from aperture 40 at a minimum rate to the exposure of each port 37 and 38 to an equivalent portion of both the expansion and contraction region. This balanced or neutral alignment results in near zero flow. As is readily apparent from this discussion, annular adjustment of the position of the ports 37 relative to the rotors 27 and 28 will produce a range of fluid flow rates between the maximum and minimum shown. Further, adjustment of the port 37 and 38 position greater than 180 degrees will result in a reversal of input and output.
Referring to FIGS. 7-14, an alternative embodiment of the gear pump apparatus 55, for use as an automobile oil pump, with automatic flow rate control. The pump 55 basically comprises a first or lower housing or body 56, a second upper housing 57, a shall 58 with end slot 64 for mating to external drive means (not shown), a port plate 59 and a plate control mechanism 60. The shall 58 rotates clockwise as viewed from the top side of the Figure. The lower housing 56 has an annular interior chamber 61 in which rotors (not shown) are disposed. The port plate 59 and upper housing have aligned apertures 62 and 63, respectively, through which the shaft 58 extends. No seals or gaskets are used in this embodiment, although fluid leakage is minimal. Such a pump design is contained in an outer housing, as is known in the art.
Referring to FIGS. 8 and 9, the lower housing 56 is a cylindrical structure with the annular chamber 61 in one end thereof, off center with respect to the central axis of the cylindrical structure. Four near-circumferentially disposed spacers 67a-d of an equivalent predetermined length extend from the chamber end. Each spacer 67 has a threaded bolt receiving aperture 68a-d disposed therein. Spacer 67c has an eye 69 for attachment of a spring (not shown).
Referring to FIGS. 10 and 11, the upper housing 57 is a relatively thin cylindrical structure with spaced, near circumferentially disposed bolt apertures 72a-d, a non-circular oil inlet aperture 73, an oil outlet aperture 74, and a halt-moon cylinder or groove 75 disposed in a bottom or interiorly facing end. The shaft 63 aperture is centrally disposed in the housing 57.
Referring to FIGS. 12 and 13, the rotors of the apparatus 55 include an outer rotor 79 and an inner rotor 80 coupled to shaft 58. The outer rotor 79 has five interiorly oriented teeth or lobes 81 and the inner rotor 80 has four exteriorly facing teeth 82. These rotors 79 and 80 define and cooperate as a gerotor set substantially as described with respect to the apparatus 10 shown in FIGS. 1-6. The gerotor set is principally disposed in chamber 61.
Referring to FIGS. 14 and 15, the port plate 59 is a disc shaped structure wherein the shaft aperture 62 is axially disposed. Symmetrical annular inlet and outlet or pressure ports 86 and 87, respectively, of a predetermined configuration and which are non-concentric with respect to the plate 59. A semicircular, half:moon piston 88 is disposed on a top end surface of the plate 59. A port pressure duct 89 communicatively extends, within the plate 59 body, from the edge of the outlet or pressure port 87 to a point on the surface of the plate 59 immediately anterior to the piston 88. A spring attaching eye 90 is disposed at a predetermined circumferential point on the plate 59. A spring 91 is connected between the port plate eye 90 and the lower housing eye 69.
In operation, the spring 91 applies force to the port plate 59 in a direction to maximize the flow rate of the pump 55 while simultaneously the piston 88 applies force to the port plate 59 to minimize the flow rate. This automatic flow control action comes to a null when a set point pressure is reached where the spring 91 force matches the piston 88 force. Thus, the spring 91 three sets the pressure at which the pump 55 operates.
As many changes are possible to the embodiments of this invention utilizing the teachings thereof, the descriptions above, and the accompanying drawings should be interpreted in the illustrative and not the limited sense. | A gear pump including a body, a port plate, a pair of gerotor-type rotors, one rotor being connected to a shaft, and a retaining assembly operative on the port plate to rotatably couple it to the body. The retaining assembly permits adjustment of axially oriented inlet and outlet ports disposed in the port plate to vary fluid flow from the pump. Both manually and automatically adjustable retaining assemblies are disclosed. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to defect inspection apparatus and a defect inspection method which are used in a manufacturing line of a semiconductor device, liquid crystal device, magnetic head or the like, and particularly relates to a calculation technique of size of a detected defect.
Inspection of a semiconductor wafer is described as an example.
In a semiconductor manufacturing process in the related art, foreign substances on a semiconductor substrate (wafer) may cause inferiority such as imperfect insulation or a short circuit. When a fine foreign substance exists in a semiconductor substrate of a semiconductor element which is significantly miniaturized, the foreign substance may cause imperfect insulation of a capacitor or breakdown of a gate oxide film. The foreign substances may be contaminated in various ways due to various reasons, such as contamination from a movable portion of a carrier device, contamination from a human body, contamination from reaction of a process gas in treatment equipment, and previous contamination in chemicals or materials. Similarly, in a manufacturing process of a liquid crystal display device, contamination of a foreign substance on a pattern, or formation of some defects disables the device as a display device. The same situation occurs in a manufacturing process of a printed circuit board, that is, contamination of the foreign substance leads to a short circuit of a pattern or imperfect connection.
It is now increasingly important to detect a defect such as foreign substance causing inferior products and take the measure for causes of the defect and thus keep a certain yield of products for stably producing a semiconductor element or a flat display device represented by the liquid crystal display device, which are expected to be further miniaturized even more in the future.
To keep the yield of products, it is necessary to determine whether a detected defect such as foreign substance has influence on the yield or not, and it is important to obtain information of a position where the defect such as foreign substance was detected, and information of size of the detected defect.
As a technique for calculating size of a defect detected by defect inspection apparatus, as described in JP-A-5-273110, a method is disclosed, in which a laser beam is irradiated to an object, and then scattering light from a particle on the object or a crystal defect therein is received and then subjected to image processing, thereby size of the particle or the crystal defect is measured. In “Yield Monitoring and Analysis in Semiconductor Manufacturing” mentioned in digest of ULSI technical seminar, pp 4-42 to 4-47 in SEMIKON Kansai in 1997, a yield analysis method using a defect by a foreign substance detected on a semiconductor wafer is disclosed.
SUMMARY OF THE INVENTION
As described above, inspection apparatus in the related art for various fine patterns including a pattern in a semiconductor device is now hard to satisfy detection accuracy of defect size required for detection of a defect on an increasingly miniaturized pattern. Therefore, it is desirable to accurately calculate size of a detected defect.
Defect inspection apparatus according to embodiments of the invention includes a unit for classifying defects into a plurality of classes based on feature quantity of the defects at detection, and modifying a size calculation method of a defect for each of classes.
That is, in embodiments of the invention, defect detection apparatus for detecting a defect of an object is configured to have an illumination unit for illuminating light to the object; a detection unit for detecting scattering light from the object; a defect detection unit for detecting the defect by processing a detection signal of the scattering light detected by the detection unit; a size measuring unit for calculating size of the defect detected by the defect detection unit; a size correction unit for correcting the size of the defect detected by the size measuring unit depending on separately obtained information of feature quantity or a type of the defect; a data processing unit for processing a result corrected by the size correction unit; and a display unit for displaying information of a result processed by the data processing unit.
According to embodiments of the invention, size of a detected defect can be accurately calculated, and for example, only defects having a size larger than a size to be managed can be extracted in semiconductor manufacturing. Thus, since a defect having higher influence on a production yield can be preferentially managed, productivity is improved in semiconductor manufacturing.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.
FIG. 1 is a block diagram showing a schematic configuration of defect inspection apparatus according to embodiments of the invention;
FIGS. 2A to 2B are graphs showing examples of defect detection signals, wherein FIG. 2A shows a case of large signal intensity, and FIG. 2B shows a case of small signal intensity;
FIGS. 3A to 3B are views showing processing for each region, wherein FIG. 3A shows an example of dividing the inside of a die (chip), and FIG. 3B shows an example of dividing a front face of a wafer;
FIGS. 4A to 4B are scatter diagrams of defect size, wherein FIG. 4A shows an example of large dispersion, and FIG. 4B shows an example of small dispersion;
FIGS. 5A to 5B are views showing examples of representative values of defect size, wherein FIG. 5A shows an example of X or Y size, and FIG. 5B shows an example of L size;
FIG. 6 is a flowchart of setting a correction factor of size calculation;
FIG. 7 is a flowchart of inspection and output;
FIGS. 8A to 8C are views showing examples of size correction using defects of which the size is known, wherein FIG. 8A shows a condition that the defects of which the size is known are disposed on a wafer, FIG. 8B shows a condition that size measured by SEM does not comparatively correspond to size detected and calculated by the defect inspection apparatus in a scatter diagram of defect size, and FIG. 8C shows a condition that the calculated size comparatively corresponds to the size measured by SEM by changing a slope of a graph by changing a factor when size of a defect detected by the defect inspection apparatus is calculated, in the scatter diagram of defect size;
FIG. 9 is a flowchart of calculating a correction factor of size;
FIGS. 10A to 10C are views showing correction examples when a defect signal is saturated, wherein FIG. 10A is a graph showing a condition that the defect signal is not saturated,
FIG. 10B is a graph showing a condition that the defect signal is saturated, and FIG. 10C is a view showing a method of predicting a peak value of a signal when a detection signal is saturated;
FIGS. 11A to 11B are scatter diagrams of defect size, wherein FIG. 11A shows a condition that size measured by SEM does not comparatively correspond to size detected and calculated by the defect inspection apparatus, and FIG. 11B shows a condition that size, which was calculated with performing correction to a defect detected by the defect inspection apparatus based on feature quantity of the defect, comparatively corresponds to the value measured by SEM;
FIG. 12 is a block diagram showing a relationship between a manufacturing process and inspection apparatus;
FIG. 13 is a graph showing a relationship between yield and the number of detected defects;
FIGS. 14A to 14B are graphs showing examples of a method of extracting a defect signal and feature quantity, wherein FIG. 14A shows a case of using a threshold obtained by a normal threshold setting method, and FIG. 14B shows a case of setting a threshold lower than a normal threshold;
FIG. 15 is a front view of a display screen showing a screen display example of the defect inspection apparatus; and
FIGS. 16A to 16B are view of an example of an illumination optical system, wherein FIG. 16A is a front view, and FIG. 16B is a side view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an example of a configuration of inspection apparatus according to embodiments of the invention (hereinafter, mentioned as defect inspection apparatus).
The defect inspection apparatus is configured to have an illumination system 100 , a stage system 200 , a detection system 300 , a Fourier transform surface observation system 500 , a signal processing section 400 , an observation optical system 600 , and a control section 2 .
Defect detection using the defect inspection apparatus shown in FIG. 1 is performed according to the following procedure. The illumination system 100 illuminates a wafer 1 set in the stage system 200 , and the detection system 300 acquires an image of the illuminated wafer 1 . The illumination system 100 adjusts output of a light source 101 by an illumination controller 103 according to an instruction value of the control section 2 . As the light source 101 , a laser light source is used, which emits laser in an ultraviolet region having a wavelength of 400 nm or less. The illumination system 100 includes a unit (not shown) for reducing coherency of the laser emitted from the laser light source. Illumination light is shaped into an appropriate form on the wafer 1 by an optical system 102 . The stage system 200 includes a rotation stage 201 , a Z stage 202 , an X stage 203 , and a Y stage 204 , and moves with respect to the detection system 300 so that the detection system 300 can scan the whole surface of the wafer 1 .
The detection system 300 includes a Fourier transform lens 301 , spatial filter 302 , focusing lens 303 , and sensor 304 . Here, the spatial filter 302 is to shield a diffraction light pattern caused by diffraction light from a repetitive pattern on the wafer 1 , and set on the Fourier transform surface of the Fourier transform lens 301 . A light shielding pattern of the spatial filter 302 is set such that a diffraction pattern of the wafer 1 is shielded, the diffraction pattern being observed by the Fourier transform surface observation system 500 having a structure that can be inserted and removed into/from an optical path of the detection system 300 . That is, the system 500 is inserted into an optical path of the detection system 300 while removing the spatial filter 302 , and then the optical path is branched by a beam splitter 501 , and an image on the Fourier transform surface of the Fourier transform lens 301 is taken by a camera 503 via a lens 502 and observed. The light shielding pattern of the spatial filter 302 can be set for each type of an object or each of steps. The light shielding pattern of the spatial filter 302 may be fixed during wafer scan, or may be changed in real time depending on a region under scanning.
An image acquired by the detection system 300 is subjected to AD conversion and then transferred to the signal processing section 400 , wherein the image is processed to detect a defect. The defect inspection apparatus further includes CPU 2 , a display device 3 , an input unit 4 , and a storage device 5 , thereby it can set any optional condition for inspection, and can store and display an inspection result or an inspection condition. Moreover, the defect inspection apparatus can be connected to a network 6 , thereby the inspection result, layout information of the wafer 1 , a lot number, the inspection condition, or an image of a defect observed by an observation device or data of a defect type can be shared over the network 6 . Moreover, the defect inspection apparatus includes the wafer observation system 600 in order to allow observation of the detected defect or an alignment mark integrally formed on the wafer 1 for alignment of a pattern formed on the wafer 1 . Furthermore, while not shown, it includes an automatic focusing unit, so that a region where an image is taken in using a sensor when the wafer is scanned on the stage system 200 is within the depth of focus of the detection system 300 .
FIGS. 2A to 2B show three-dimensional display of examples of signal detection of two types of defects A and B respectively. FIGS. 2A to 2B exemplify defects having different signal intensity detected by the defect inspection apparatus while having the same size. A vertical direction represents signal intensity, showing intensity for each pixel. Even if defects (foreign substances) have the same size in SEM (scanning electron microscope) observation, detection signals in the defect inspection apparatus may be varied depending on a defect type, defect position, and surface pattern or surface material of the wafer 1 . Thus, size of defects obtained through detection by the defect inspection apparatus according to embodiments of the invention are corrected based on information of the defect type, defect position, and surface pattern or surface material of the wafer 1 , thereby size calculation accuracy of defects can be improved.
Moreover, to improve the size calculation accuracy of a defect, it is important to modify a detection condition depending on a position of the defect. Thus, in the defect inspection apparatus according to embodiments of the invention, grouping is carried out depending on fineness of a pattern in a detection portion of the wafer 1 or each of many dies (chips) formed on the wafer 1 , so that a detection condition of the defect can be modified.
FIGS. 3A to 3B show examples of grouping for each of regions in the wafer or die (chip). FIG. 3A shows an example of grouping the inside of the die depending on a type of a circuit pattern. A reference 3001 shows a region where awiring pattern is random in the die, and a reference 3002 shows a region where the wiring pattern is repeated at a constant pitch. FIG. 3B shows an example of grouping of the whole surface of the wafer 1 . A reference 3003 indicates a central portion of the wafer 1 , and a reference 3004 indicates the outer circumferential portion of the wafer. A reference 3005 indicates a die. In the case of a fine pattern, interference of illumination light may occur due to a pattern near a defect and the defect, and thus a detection signal of a defect may be different from that in the case of detecting a defect near a coarse pattern, and therefore grouping is carried out depending on regions. Moreover, when thickness is uneven in a wafer surface due to deposition, etching, or polishing, since a detection signal of a defect may be varied due to interference of light as well, grouping is carried out.
FIGS. 4A to 4B show an evaluation method of dimension accuracy of a defect. A graph is displayed on a screen, in which measured values of size by defect observation apparatus such as SEM are plotted as a horizontal axis, and calculated values of size by the defect inspection apparatus are plotted as a vertical axis, which allows visual expression of calculation accuracy of defect size. FIG. 4A shows an example of large dispersion of defect distribution, that is, low dimension accuracy. FIG. 4B shows an example of small dispersion of defect distribution compared with the example of FIG. 4A , that is, high dimension accuracy.
FIGS. 5A to 5B are views for illustrating a way of defining a measured value when defect size is measured by the defect observation device such as SEM. X and Y are coordinate axes used in observation of a defect by SEM. In a way of expressing the defect size, projected length in an X-axis direction (X size), projected length in an Y-axis direction (Y size), diameter of a circumscribed circle of a defect (L; major axis size), √(X+Y), or √(X 2 +Y 2 ) can be used as a representative value. In yield management, one of the diameter of the circumscribed circle of the defect (L; major axis size), √(X+Y), and √(X 2 +Y 2 ), or a combination of them is used.
FIG. 6 shows a condition setting flow for correcting size of a defect detected by the defect inspection apparatus. In embodiments of the invention, a correction factor that was determined and stored according to the flow of FIG. 6 is used, and size of a defect on the wafer, which was inspected and detected by the defect inspection apparatus according to a flow shown in FIG. 7 , is calculated, and then inspection data added with size is registered into a defect management server.
A flow of FIG. 6 is described below. Inspection is performed using the defect inspection apparatus in S 601 , and defects to be observed by the defect observation apparatus such as SEM are selected from defects detected using the defect inspection apparatus in S 602 . When the number of defects is small, for example, about 100, the whole number of them may be selected. When the number of defects is large, while they may be randomly extracted, if defects to be observed are extracted using SSA (Spatial Signature Analysis) based on a distribution condition in a wafer plane, several types of defects in a wafer can be evenly extracted. After defects as objects are selected in S 602 , size or a type (convex defect, concave defect, planar defect or the like) of the defect as object selected by the defect observation apparatus such as SEM is obtained in S 603 . After that, based on information of the size or type of the defect, a size calculation result of the defect inspection apparatus is compared with a measurement result of the defect observation apparatus such as SEM to create a scatter diagram as shown in FIG. 4 in S 604 , then a correction factor is determined depending on the size or type of the defects in S 605 , and then stored in S 606 .
Comparison between the size calculation result of the defect inspection apparatus and the measurement result of the defect observation apparatus such as SEM in S 604 can be carried out by the defect inspection apparatus, SEM, a separated personal computer or the like. Since creation of the scatter diagram in S 604 is intended to be for reference when a user adjusts a condition, in the case that the correction factor is automatically calculated, it need not always be shown diagrammatically. In correction in S 605 , linear correction (y=ax+b): (x is defect size calculated by the defect inspection apparatus, y is size after correction, a is a correction factor, and b is an offset value) may be used, or a higher-order transformation equation may be used for the correction. Regarding a way of determining the correction factor a or the offset value b, one of a value previously registered into the defect inspection apparatus, a value adapted for each treatment step in wafer manufacturing, and a value corresponding to a defect type or feature quantity of a defect, or a combination of them may be used.
After the correction factor has been calculated in S 605 , the correction factor is stored in S 606 , consequently condition setting for size calculation is completed.
FIG. 7 shows a flow of inspection and output. A wafer is inspected (S 701 ), then classification of defects is performed based on a defect type or feature quantity of a defect (S 702 ). Defect size is calculated in S 703 , and then size is corrected for each defect class using the correction factor previously set according to the flow described using FIG. 6 in S 704 . A size calculation result S 705 after correction is added to the defect detection result, then data of them are transferred to a defect management server (S 706 ).
FIGS. 8A to 8C show a method of size calibration using a defect having known size. FIG. 8A shows a standard wafer in which the defects having known size are integrally formed, or a product wafer, dummy wafer, or mirror wafer on which standard particles are scattered, wherein defects 901 (size A (nm)), 902 (size B (nm)), and 903 (size C (nm)) having known size are integrally formed.
FIG. 8B shows an aspect that the size detected and calculated by the defect detection apparatus is different from the size measured by SEM depending on a surface condition or surface material of a wafer due to an adjustment condition of the defect detection apparatus or difference in machine, indicating a relationship between actual size of the defects 901 , 902 and 903 having known size, which were measured using SEM, and size of the defects detected and calculated by the defect detection apparatus. A reference 904 indicates an approximate curve. Based on the approximate curve of 904 , a factor in size calculation is changed so that a slope of a graph is corrected to be approximately 45 degrees ( FIG. 8C ), thereby a value of the defect size detected and calculated by the defect detection apparatus can be calibrated.
FIG. 9 shows a flow of obtaining a factor for correcting size. First, a wafer is inspected to detect a defect using the defect inspection apparatus according to embodiments of the invention (S 901 ), then a sum signal of detection signals in the whole region of the detected defect is calculated (S 902 ). Since part of the detected defects may be beyond a dynamic range of the sensor 304 , saturating signal correction (S 903 ) is performed, and size is temporarily calculated (S 904 ). In this time point, since the calculated size may be different from actual size measured by SEM, an approximate formula is then calculated (S 905 ), and then a correction factor is calculated according to the approximate formula (S 906 ). For correction, linear correction (y=ax+b): (x is defect size calculated by the defect inspection apparatus, y is size after correction, a is a correction factor, and b is an offset value) may be used, or a higher-order transformation equation may be used.
FIGS. 10A to 10C show a specific example of the saturating signal correction of the step S 903 in FIG. 9 . FIG. 10A shows an example of a defect of which the signal is not saturated, wherein d 01 indicates a signal peak. FIG. 10B shows signal intensity (d 02 ) of a defect of which the signal is partially beyond a dynamic range of a sensor during detection of a defect signal and thus saturated. As shown in FIG. 10C , a portion where a defect signal is lacked because of saturation is approximated by an appropriate function, so that a signal of a lacked portion is estimated, thereby a saturating signal can be corrected. For example, when a defect signal is approximated by Gaussian curve, a value of the number of saturated pixels (d 03 ) and broadening of Gaussian distribution (standard deviation) are supposed, thereby a peak (d 04 ) of the defect signal can be estimated.
FIGS. 11A to 11B show correction based on feature quantity of a defect. A correction factor is obtained according to a procedure shown in FIG. 6 for each defect type (convex defect, concave defect, planar defect or the like), then a correction factor of defect size is modified based on feature quantity of a defect according to a procedure of FIG. 7 , thereby dimension accuracy can be improved. FIG. 11A is a scatter diagram of defect size, showing a condition that size measured by SEM does not comparatively correspond to size detected and calculated by the defect inspection apparatus. On the contrary, FIG. 11B is a scatter diagram of defect size in a condition that size, which was calculated with performing correction based on feature quantity of a defect (for example, defect size) to a defect defected by the defect inspection apparatus, comparatively corresponds to size measured by SEM. Size may be calculated by obtaining the correction factor for each defect type (convex defect, concave defect, planar defect or the like), rather than the feature quantity of a defect.
While a procedure of temporarily obtaining size before correction is shown here, size may be calculated at a time during size calculation using information such as feature quantity of a defect or the defect type. For this purpose, information on defects such as feature quantity of a defect or a defect type can be treated as a variable in a size calculation formula in size calculation.
FIG. 12 shows a relationship between the defect inspection apparatus according to embodiments of the invention and a semiconductor manufacturing process. A wafer after passing through a particular step is inspected by the defect inspection apparatus according to embodiments of the invention. In a manufacturing process 810 , for example, inspection is carried out after a photolithography step ( 810 ). After the inspection, a defect is observed by review apparatus 1001 or 1002 , so that a cause of the defect is estimated from a type, size, or a shape of the defect to find a step where the defect is caused, thereby a manufacturing device in the relevant step is managed. When the cause of the defect is not found only by defect observation, element analysis by an analyzer 1003 or observation of a section profile of the defect is performed for further detailed investigation to search the cause of the defect. As described above, a yield of the semiconductor device is improved by repeating inspection and measures, consequently reliable semiconductor device can be manufactured.
FIG. 13 shows a relation between the number of defects and a yield of a semiconductor product. A reference 906 indicates transition of the yield of the semiconductor product, a reference 907 indicates transition of total detection number of defects in a particular step. A reference 908 indicates transition of the number of a particular type of defects (in this case, short-circuit defect). While the yield 906 is significantly decreased in a hatched period in FIG. 13 , the total detection number 907 is increased only slightly. When the detected defects are classified, and the number of short-circuit defects is noticed, it is known that the short-circuit defects are increased in the period where the yield is decreased. In addition to the total number of defects, defects are classified, and the number is monitored for each defect type, thereby information in correlation with the yield of the semiconductor product can be obtained. The number of defects of which the size is at least management size may be noticed and managed by using a defect size calculation value rather than the defect type. The management size is determined based on a wiring rule in an inspection step. While not shown, criticality of the defect may be calculated from the defect size, defect type, and wiring rule to monitor the number of defects having at least a certain value of criticality.
FIGS. 14A to 14B are conceptual diagrams of defect detection thresholds T 01 , T 02 and a feature-quantity extraction threshold T 03 . FIG. 14A shows an example where the defect detection threshold T 01 is equal to the feature-quantity extraction threshold T 03 . In inspection of a semiconductor wafer, the defect detection threshold T 01 is normally set high to suppress false detection of a normal portion. Therefore, in FIG. 14A , only a part of defect signals can be used. Thus, as shown in FIG. 14B , the feature quantity is extracted with a threshold (T 04 ) lower than the defect detection threshold T 02 , thereby more effective extraction of the feature quantity can be performed.
FIG. 15 shows a display example of a defect detection result. A reference 801 indicates an example of a display screen. In a defect map ( 802 ), display is classified depending on whether defect size is at least a defect management size determined at setting of inspection conditions or not, thereby trouble occurrence and a level of influence on the yield can be instinctively determined. Moreover, defect display is clicked by a mouse, thereby defect ID, size (calculation value of the defect inspection apparatus), a defect type and the like can be shown ( 803 ).
Moreover, a graph showing frequency of defect occurrence is displayed for each defect size ( 807 ), thereby the trouble occurrence and the level of influence on the yield can be also instinctively determined.
On the screen, a region 804 for displaying the total number of detected defects or the number of the defects for each size, a region 805 for displaying an operational panel, a region 806 for setting a inspection condition, a region 808 for displaying a defect list are also provided. The display regions may be displayed on one screen at the same time, or may be displayed on separated screens respectively, or several regions of them may be displayed in a combined manner.
FIG. 16 shows an example of the illumination optical system 102 in the configuration of the defect inspection apparatus shown in FIG. 1 . Here, an example where the light source 101 is a laser light source is shown. Laser 1011 emitted from the laser light source 101 is diverged at a certain divergence angle, and made into parallel light by a lens 1021 , and then shaped to be one-sided condensing illumination by a cylindrical lens 1022 and then irradiated to a wafer surface. An illumination pattern is linear on the wafer surface, and used in a combined manner with scan of the stage, thereby a certain area of the wafer surface can be collectively detected. In this case, for the sensor 304 , a linear sensor corresponding to the illumination area or a TDI sensor (Time Delay Integration Sensor) is preferably used. When the TDI sensor is used for the sensor 304 , a signal detected by the TDI sensor is outputted in parallel from a plurality of taps of the TDI sensor, and the signals outputted in parallel are subjected to signal processing in parallel in the signal processing section 400 , thereby defect detection speed can be improved. When the illumination pattern is a dot-like pattern, AOM, AOD, a galvanometer mirror or the like is used in the illumination optical system to allow scan by the dot-like illumination, and movement of the stage is combined therewith, thereby the whole surface of the wafer can be inspected.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | When size of a defect on an increasingly miniaturized pattern is obtained by defect inspection apparatus in the related art, a value is inconveniently given, which is different from a measured value of the same defect by SEM. Thus, a dimension value of a defect detected by defect inspection apparatus needs to be accurately calculated to be approximated to a value measured by SEM. To this end, size of the defect detected by the defect inspection apparatus is corrected depending on feature quantity or type of the defect, thereby defect size can be accurately calculated. | 6 |
This is a continuation application of U.S. application Ser. No. 10/872,485, filed Jun. 22, 2004, now U.S. Pat. No. 7,785,534, the contents of which are hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reagent dispensing system for an automatic analyzer that automatically performs a qualitative/quantitative analysis of a biological sample such as blood, urine, or the like, and an automatic analyzer using the same. More particularly, the present invention concerns an automatic analyzer that uses reagent containers each having an information recording medium on which information about a reagent contained in the reagent container is recorded, and that is capable of reliably reading the information recorded on the aforementioned information recording medium while allowing the reagent-container mounting density per unit area to be increased.
2. Description of the Related Art
The automatic analyzer that automatically performs a qualitative/quantitative analysis of a biological sample such as blood, urine, or the like, has become prevalent mainly in medical laboratories and large hospitals, since it can meet the expectations for improvement in the quantitativity of analysis result and the speedup of analysis. The measurement principle of the automatic analyzer is to mix a sample that changes in color as a result of reacting with a component to be analyzed, with a sample, and then to measure the change in the color of the sample. Conventionally, the measurement of this change in color has been performed by a laboratory technician using a calorimetric table, whereas in the automatic analyzer, the measurement of the change in color is performed by means of a photometer, thereby achieving improvement in the quantitativity of analysis result and the speedup of analysis.
In recent year, in order to improve the operator-friendliness of the apparatus, various techniques have been proposed. One of them is to record information, such as the kind of reagent, on an information recording medium such as a barcode label, and to automatically identify the kind of the reagent by reading this information recording medium. When the operator must input the kind of reagent into a computer, if the kind of reagent is inputted in error, there occurs a possibility of an erroneous analysis result being reported, whereas the method using the information recording medium as described above would be expected to reduce load upon the operator, and also decrease possibility of causing an error in analysis result.
With the diversification of analysis items, market demands an automatic analyzer capable of mounting thereon more reagents and simultaneously having a compact size. However, the barcode, which is the mainstream of conventional information recording media, is read by an optical manner, and therefore, mounting reagent containers at high density unfavorably inhibits the barcode from being read. To solve this problem, Japanese Patent No. 3274325 proposes to arrange reagent disks along respective circumferences of the double concentric circles, and simultaneously, in order to read the barcode of the reagent container on the inner peripheral side, this patent document proposes to provide a portion devoid of reagent in a row of reagent containers on the outer peripheral side, and read the barcode of the reagent container on the inner peripheral side, from the aforementioned portion. This method allows the enhancement of the mounting density of reagent containers and the identification of reagent by the barcode to be mutually compatible.
SUMMARY OF THE INVENTION
In the method disclosed in the above-described patent document, the disposition of the reagent containers placed on the outer peripheral side is limited because of the necessity for reading the barcode of the reagent container on the inner peripheral side. If the reagent disks are arranged in double concentric circles, it is deemed that the aforementioned limitation is not so big a problem. However, if the reagent disks are arranged in no less than triple concentric cylinders in order to increase the mounting density, a significant disadvantage might be caused.
Accordingly, it is an object of the present invention to provide an automatic analyzer that is capable of mounting reagent containers at a higher density while using reagent containers each having an information recording medium for identifying a reagent.
To achieve the above-described object, the present invention provides a reagent dispensing system that includes a reagent container for holding a reagent; a reagent cold-storage chamber for keeping a plurality of the reagent containers at a low temperature; a reagent dispensing device for sucking, from an arbitrary reagent container held in the reagent cold-storage chamber, a reagent in the reagent container. In this reagent dispensing system, the lid of the reagent cold-storage chamber is divided into at least two portions: a movable portion that is openable and closable, and that is used for taking out the reagent container; and an fixed portion that is non-openable and non-closable, and that is provided fixedly with respect to the cold-storage chamber. Herein, the fixed portion has an information reading section for reading information of a recording section that is provided to the reagent container, and that records information including information about the reagent in the reagent container.
In the reagent dispensing system according to the present invention, it is preferable that the recording section be disposed on the top surface of the reagent container.
In the reagent dispensing system according to the present invention, the recording section may exchange information with the information reading section by radio waves.
In the reagent dispensing system according to present invention, the fixed portion of the lid may have an opening for the reagent dispensing device to suck a reagent from the reagent container, and the information reading section may be disposed in the vicinity of the aforementioned opening.
In the reagent dispensing system according to present invention, the information reading section may read information of the information recording section of the reagent container immediately before the reagent dispensing device sucks a reagent from the reagent container, and the reagent dispensing device may suck a reagent after the aforementioned reagent has been checked to be sure that it is a desired reagent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A , 1 B, and 1 C are each a schematic view of a reagent container to be mounted on an automatic analyzer, according to a first embodiment of the present invention;
FIG. 2 is a sectional view of a reagent cold-storage chamber of the automatic analyzer according to the present invention;
FIG. 3 is a schematic view of the automatic analyzer according to the present invention;
FIGS. 4A and 4B are each a schematic view of a conventional reagent container;
FIG. 5 shows an example of an efficient layout of reagent containers;
FIGS. 6A and 6B are each a top view showing an example of layout of reagent containers on a reagent disk;
FIG. 7 is a sectional view of a reagent cold-storage chamber of an automatic analyzer according to a second embodiment of the present invention, the reagent cold-storage chamber having the reagent container layout shown in FIG. 6A or 6 B;
FIG. 8 is a sectional view of a reagent cold-storage chamber of an automatic analyzer according to a third embodiment of the present invention, the reagent cold-storage chamber having the reagent container layout shown in FIG. 6A or 6 B;
FIG. 9 is a sectional view of a reagent cold-storage chamber of an automatic analyzer according to a fourth embodiment of the present invention, the reagent cold-storage chamber having the reagent container layout shown in FIG. 5 ;
FIG. 10 is a sectional view of a reagent cold-storage chamber of an automatic analyzer according to a fifth embodiment of the present invention, the reagent cold-storage chamber being equipped with a mechanism having mirrors;
FIG. 11 is another sectional view of the reagent cold-storage chamber of the automatic analyzer according to the fifth embodiment of the present invention, the reagent cold-storage chamber being equipped with the mechanism having the mirrors; and
FIG. 12 is a sectional view of a reagent cold-storage chamber of an automatic analyzer according to a sixth embodiment of the present invention, the reagent cold-storage chamber being equipped with a mechanism having a mirror.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Typically, in the automatic analyzer, a barcode label, which can record information intended for identifying or necessary to manage a reagent, is attached on a side surface of a reagent container for storing a chemical agent used for analyzing components of a sample to be analyzed. A possible alternative way to read or write information is to provide the automatic analyzer with a recording medium that writes or reads information by an electric or magnetic method, or using a method combining these electric and magnetic methods. The barcode reader for reading information stored in a storage medium such as the aforementioned barcode label, or the writing/reading mechanism making use of an electrical or magnetic coupling, or a method combining the electric and magnetic coupling, is provided on a side surface of the reagent container. Each of them reads manually or automatically information about the kind of reagent and information necessary for analysis from the side direction of the reagent container when a reagent bottle is set in the apparatus. Alternatively, when powering on the apparatus, re-reading is automatically performed as a general rule in order to identify the reagent already mounted.
In the automatic analysis, in order to perform analyses of more items, it is required to mount more kinds of reagents, and therefore, the number of reagent containers mounted must be increased. On the other hand, it is desired that the overall size of the apparatus be reduced from the viewpoint of the floor area of a facility. Hence, it follows that the mounting density of reagent containers must be enhanced.
For that purpose, as shown in FIG. 5 , the distance between reagent containers must be reduced to a minimum. However, if the configuration shown in FIG. 5 is adopted, when attempting to perform the re-reading of the reagent management information at power-on using the method in which information is provided on at least one side surface of a reagent container as conventional examples (see FIGS. 4A and 4B ), a user has no alternative but to once take out the reagent container, and after transferring it to another place, perform the re-reading of the information. This unfavorably requires much time.
Typically, in the method in which information is provided on a side surface of a reagent container, a way in which reagent containers are arranged in circles, and in which a reading/writing mechanism is provided outside the reagent containers arranged in circles as shown in FIGS. 6A and 6B , is employed. However, when the reagent container has a rectangular parallelepiped shape or a cubic shape, a reagent housing case having a circular shape would have much useless space. To solve this problem, fan-shaped reagent containers are used for some apparatuses. As shown in FIGS. 6A and 6B , when reagent containers are housed by dividing them into ones on the outer peripheral side and ones on the inner peripheral side in order to increase the number of mounted reagent containers, a barcode reader, which utilizes light, is used to read information about reagent containers disposed along the inner periphery. In this case, the distance between the reagent containers disposed along the outer periphery must be widened up to a distance that allows the barcodes on the reagent containers on the inner peripheral side to be read. The above-described structure, therefore, reduces the mounting density of reagent containers.
Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.
First Embodiment
FIGS. 1A , 1 B, and 1 C are each a schematic view of a reagent container 1 for storing a reagent necessary for analysis and mounted on an automatic analyzer, according to a first embodiment of the present invention. Depending upon a specification of the apparatus, the reagent container 1 has a rectangular parallelepiped shape or a fan shape. A reagent ID 2 that can store information necessary for the management of reagent is attached on the top surface of the reagent container 1 . The reagent ID 2 is constituted of a barcode, semiconductor storage medium, magnetic storage medium, optical storage medium, or the like.
As shown in FIG. 3 , the reagent container 1 is mounted on a reagent disk 9 in a reagent storage section 21 . The reagent storage section 21 according to the first embodiment is shown in FIG. 2 . In FIG. 2 , a plurality of reagent containers 1 can be mounted on a reagent disk 21 having a circular shape. The reagent container 1 and the reagent disk 9 are thermally insulated by a reagent cold-storage chamber 7 and the lid 8 of the reagent cold-storage chamber 7 . A plurality of reading/writing mechanisms 5 is provided to the lid 8 of the reagent cold-storage chamber 7 , and can read or write information that is necessary for the analysis of a sample, and that is stored in the reagent ID 2 attached on the top surface of the reagent container 1 , by a non-contact method or a contact method through the use of electromagnetic waves, magnetism, light, or the like. The information about a reagent that is necessary for analysis and that has been read by the reading/writing mechanisms 5 is sent to an information control section 6 by a communication line 16 , and it is utilized for an analytical operation by the automatic analyzer. The information control section 6 writes, into the reagent ID 2 , reagent management information that has been occurred as a result of the present automatic analyzer operating and that is represented by the number of times of reagent usage, reagent unsealing date, reagent expiration date and the like, by means of the reading/writing mechanisms 5 . The reagent disk 9 rotates in the horizontal direction under the drive from a motor 11 for rating the reagent disk 9 , and transfers the reagent container 1 to a predetermined position that allows a reagent inside the reagent container 1 to be sucked by a reagent nozzle 14 of a reagent dispensing device 15 , or a predetermined position that allows information necessary for analysis and stored inside the reagent ID 2 to be read or written by the reading/writing mechanisms 5 . As shown in FIG. 3 , the automatic analyzer with the above-described features dispenses a sample stored in a sample container 30 mounted on a sample rack 29 situated in a sampler section 23 into a reaction cell 22 in an analysis section 20 by a sample probe 24 . The automatic analyzer then dispenses a reagent in the reagent storage section 21 into the aforementioned reaction cell 22 by a reagent probe 25 . Thereafter, the automatic analyzer stirs and mixes the sample and the reagent by a stirring mechanism 28 , and detects the process of chemical reaction between the sample and the reagent and analyzes components included in the sample by a detector 27 . In this embodiment, the reagent ID 2 is attached on the top surface of the reagent container 1 . However, the reagent ID 2 may be attached on the undersurface of the reagent container 1 , and the reading/writing mechanisms 5 may also be disposed below the reagent containers 1 . Alternatively, the reagent ID 2 may be attached both on the top surface and undersurface of the reagent container 1 .
Second Embodiment
FIG. 7 is a schematic view of an automatic analyzer according to a second embodiment of the present invention, wherein reagent containers 1 are arranged along the inner periphery and the outer periphery of the reagent disk 9 in a concentric manner as shown in FIGS. 6A and 6B , in order to increase the number of reagent containers mounted on the automatic analyzer 1 . In this embodiment, the automatic analyzer has a transfer mechanism 35 for the reading/writing mechanism 5 in order to transfer the reading/writing mechanism 5 . This transfer mechanism 35 for the reading/writing mechanism 5 transfers the reading/writing mechanism 5 in the X, Y, and Z axis directions, and the rotational direction, whereby the reading/writing mechanism 5 is transferred to a position that allows information necessary for analysis, and stored inside the reagent ID 2 on the reagent container 1 situated at an arbitrary position, to be read by the reading/writing mechanism 5 .
When the moving range of the transfer mechanism 35 for the reading/writing mechanism 5 is limited, or when the moving distance or the moving time thereof must be reduced, the reagent disk 9 in this embodiment horizontally rotates under drive from the motor 11 for rotating the reagent disk 9 , and transfers the reagent container 1 to a position where a reagent inside the reagent container 1 is to be sucked by the reagent nozzle 14 , or a position that allows information necessary for analysis and stored inside the reagent ID 2 to be read or written by the reading/writing mechanism 5 .
Third Embodiment
FIG. 8 is a schematic view of an automatic analyzer according to a third embodiment of the present invention intended for the reduction in the number of the reading/writing mechanisms 5 in the first embodiment. In this embodiment, the detection section of a reading/writing mechanism 5 located above a rotary-type reagent disk 9 and reagent containers 1 has a size long enough to straddle reagent IDs 2 on a plurality of reagent containers, and reads a single reagent ID 2 or a plurality of reagent IDs 2 without the need for the rotation of the reagent disk 9 and the movement of the reading/writing mechanism 5 .
Fourth Embodiment
FIG. 9 is a schematic view of an automatic analyzer according to a fourth embodiment of the present invention, wherein, for the purpose of increasing the number of reagent containers 1 mounted on the automatic analyzer, the reagent containers 1 are arranged in a manner as shown in FIG. 5 , i.e., not in a concentric manner. In this embodiment, there is not provided a rotary-type reagent disk 9 as present in FIGS. 2 , 7 , and 8 , and the reagent containers 1 are provided in the reagent cold-storage chamber 7 in a lattice-like arrangement. The reading/writing mechanisms 5 is transferred by the transfer mechanism 35 for the reading/writing mechanism 5 to a position that allows information necessary for analysis, and stored inside the reagent ID 2 on the reagent container 1 that is situated in an arbitrary position out of the reagent containers 1 disposed in fixed positions in the automatic analyzer, to be read by the reading/writing mechanism 5 .
Fifth Embodiment
FIGS. 10 and 11 are each a schematic view of an automatic analyzer according to a fifth embodiment of the present invention in which, for the purpose of increasing the number of reagent containers 1 mounted on the automatic analyzer, the reagent containers are arranged in a concentric manner along the outer periphery and the inner periphery of the reagent disk 9 as illustrated in FIGS. 6A and 6B , and which is intended for the reduction in the number of the reading/writing mechanisms 5 . The reading/writing mechanism 5 used in this embodiment is a reading mechanism for reading a reagent ID 2 using light represented by a barcode reader. To the lid 8 of the reagent cold-storage chamber 7 , one reading/writing mechanism 5 , two fixed mirrors 37 , and one movable mirror 36 are affixed. The movable mirror 36 is formed into a pent-roof shape by combining two mirrors, with its reflecting surface facing the outside. This movable mirrors 37 are fixed to a mirror operating mechanism 38 , and moves toward or away from the fixed mirrors 37 in accordance with a movement of the mirror operating mechanism 38 . Above the reagent containers on the inner peripheral side and the outer peripheral side of the reagent disk 9 , the two fixed mirrors 37 are affixed to the lid 8 of the reagent cold-storage chamber 7 . The reading/writing mechanisms 5 is located substantially above the top of the movable mirror 36 , which is formed into a pent-roof shape by combining two mirrors. These reading/writing mechanisms 5 , fixed mirrors 37 , and movable mirror 36 each have a disposition that allows information necessary for analyzing a sample, and stored in the reagent ID 2 attached on the top surface of the reagent container 1 , to be sent to the reading/writing mechanisms 5 through an optical path 39 . The movable mirror 36 has a structure so as to be moved by the mirror operating mechanism 38 to a position where, as shown in FIG. 10 , information that is necessary for analyzing a sample, and that is stored in the reagent ID 2 attached on the top surface of the reagent container 1 on the inner peripheral side of the reagent disk 9 , is to be read, or to a position where, as shown in FIG. 11 , information that is necessary for analyzing a sample, and that is stored in the reagent ID 2 attached on the top surface of the reagent container 1 on the outer peripheral side of the reagent disk 9 , is to be read.
Sixth Embodiment
FIG. 12 is a schematic view of an automatic analyzer according to a sixth embodiment of the present invention in which, for the purpose of increasing the number of reagent containers 1 mounted on the automatic analyzer, the reagent containers are arranged in a concentric manner along the outer periphery and the inner periphery of the reagent disk 9 as illustrated in FIGS. 6A and 6B , and which is intended for the reduction in the number of the reading/writing mechanisms 5 . The reading/writing mechanism 5 used in this embodiment is a reading mechanism for reading a reagent ID 2 using light represented by a barcode reader. To the lid 8 of the reagent cold-storage chamber 7 or above it, one reading/writing mechanism 5 , and basically one movable mirror 36 are affixed. The movable mirror 36 is fixed to a mirror operating mechanism 38 , and has a structure so as to be able to change the orientation of its reflecting surface in accordance with a movement of the mirror operation mechanism 38 . These reading/writing mechanisms 5 and movable mirror 36 each have a disposition that allows information necessary for analyzing a sample, and stored in the reagent ID 2 attached on the top surface of the reagent container 1 , to be sent to the reading/writing mechanisms 5 through an optical path 39 . Also, as shown in FIG. 12 , the movable mirror 36 has a structure so as to be moved by a mirror operating mechanism 38 to a position where information that is necessary for analyzing a sample and that is stored in the reagent ID 2 attached on the top surface of the reagent container 1 on the inner peripheral side of the reagent disk 9 , is to be read, or to a position where information that is necessary for analyzing a sample and that is stored in the reagent ID 2 attached on the top surface of the reagent container 1 on the outer peripheral side of the reagent disk 9 , is to be read.
As is evident from the foregoing, according to the present invention, it is possible to provide an automatic analyzer that allows the apparatus cost to be reduced by an inexpensive mechanism, and that enables the throughput and the number of processing items of the apparatus to be increased. | An automatic analyzer is disclosed that has a structure capable of using reagent containers each having an ID, such as a barcode, attached either on the top surface or the undersurface thereof, or alternatively on each of them. This automatic analyzer, therefore, allows information about the reagent ID to be read or written at an arbitrary timing even if the mounting density of reagent containers of the automatic analyzer is increased, thereby improving the function and performance of the apparatus. | 8 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] This invention relates generally to the analysis of electromagnetic signals to identify biomarkers for cognitive, language and behavioral disorders, of known or unknown etiology (collectively referred to herein as ‘developmental disorders’), and more specifically to analyzing EEG data using complexity and/or synchronization measures in infants to identify characteristics associated with developmental disorders including autism spectrum disorder (ASD).
[0003] 2. Related Art
[0004] Normal and abnormal behavior are differentiated by subtle, complex patterns of activity that an expert clinician observes or discovers through systematic diagnostic tests. In practice, the vast majority of pediatric neuropsychiatric and neurological assessment is based on observing behaviors or by asking caregivers about the child in an effort to understand brain function. Such assessment is particularly difficult in infants and young children who may exhibit a limited set of behaviors and limited communication abilities.
[0005] If brain function and behavior are mirrors of each other, as is commonly accepted, then biomarkers of developmental disorders may be hidden in subtle, complex patterns of neurobiological data. Furthermore, the range of mental disorders with a developmental etiology now includes schizophrenia, psychopathy and antisocial behavior disorders, susceptibility to post-traumatic stress syndrome, as well as autism and other pervasive developmental disorders and neurological disorders such as epilepsy that emerge during childhood. An important factor in understanding developmental developmental disorders is the relationship between functional brain connectivity and cognitive, behavioral and language development. This challenge is difficult in part because the brain is a complex, hierarchical system and few methods are available for noninvasive measurements of brain function in developing infants and young children.
[0006] The human brain contains on the order of 10 11 neurons and more than 10 14 synaptic connections. Although sparsely connected, each neuron is within a few synaptic connections of any other neuron. This remarkable connectivity is achieved by a kind of hierarchical organization that is not fully understood in the brain, but is ubiquitous in nature, called scale-free or complex networks. Complex networks are characterized by dense local connectivity and sparser long-range connectivity that is fractal or self-similar at all scales. A comparison of network properties using functional magnetic resonance imaging (fMRI) showed that children and young-adults' brains have similar “small-world” organization at the global level, but differ significantly in hierarchical organization and interregional connectivity.
[0007] The explosive growth of neuroimaging studies that link functional brain activity to behavior promises exciting opportunities for measuring nonlinear brain activity that may indicate abnormalities or allow response to therapy to be monitored. Measurements of brain electrical activity with electroencephalography (EEG) have long been a valuable source of information for neuroscience research, yet this rich resource may be under-utilized for clinical applications in neurology and psychiatry. To fully exploit this data, methods for discovering subtle patterns in nonlinear features and deeper understanding of the relationship between emergent signal features and the underlying neurophysiology are needed.
[0008] EEG measurements are safe and the technique is relatively easy to use even with very young children. EEG signals are believed to derive from pyramidal cells aligned in parallel in the cerebral cortex and hippocampus, which act as many interacting nonlinear oscillators. As a consequence of the scale-free network organization of neurons, EEG signals exhibit complex system characteristics reflecting the underlying network topology, including various entropy measures, transient synchronization between frequencies, short and long range correlations and cross-modulation of amplitudes and frequencies. While more research is needed to completely understand the relationship between neural network topology and the characteristics of EEG machine learning algorithms can be used now to find clinically-relevant relationships between signal features and brain function.
[0009] Many different methods for computing the complexity of a signal have been defined and used successfully to analyze biological signals. A measure called multiscale entropy (MSE) was shown to be a remarkable biomarker for cardiac health when computed from EKG signals. Sample entropy, upon which MSE is based, has been shown to be significantly higher in certain regions of the right hemisphere in pre-term neonates that received skin-to-skin contact than in those that did not, indicating faster brain maturation. Signal complexity has also been used as a marker of brain maturation in neonates and was found to increase prenatally until maturation at about 42 weeks, then decreased after newborns reached full term. A study of the correlation dimension (another measure of signal complexity) of EEG signals in healthy subjects showed an increase with aging, interpreted as an increase in the number of independent synchronous networks in the brain. Other measures of signal complexity have also been shown to be related to various aspects of brain function and cognition, including the scale dependent Lyapunov exponent (SDLE).
SUMMARY OF THE INVENTION
[0010] The inventor has recognized and appreciated that measureable nonlinear features in electromagnetic EEG signals may potentially be used as biomarkers of normal or abnormal cognitive development. In particular, methods from complex systems theory for analyzing the depth of information contained in these signals may be used to characterize functional brain development during early childhood. To this end, some embodiments are directed to analyzing electromagnetic data using one or more measures of complexity and/or synchronization to characterize developmental disorders such as autism.
[0011] Although the techniques described herein are generally applicable to the analysis of electromagnetic data to characterize brain function, some embodiments are particularly directed at analyzing electromagnetic data recorded from infants and young children who, as discussed above, may have limited behavioral and/or communication repertoires. Accordingly, some embodiments are directed to analyzing the complexity and/or synchronization of EEG data collected from infants and/or young children to elucidate brain functions that may not be observable at such a young age. Such quantitative measures of brain function may provide a reliable way to perform risk assessment and/or diagnosis of neurodevelopmental abnormalities early in life.
[0012] The neurophysiological mechanisms that underlie normal and abnormal cognitive function may not be understood by pure reduction to physiological causes. The dynamics of the brain are inherently nonlinear, exhibiting emergent dynamics such as chaotic and transiently synchronized behavior that may be central to understanding the mind-brain relationship or the ‘dynamic core’. Some studies suggest that complex mental disorders such as autism cannot easily be described as associated with underconnectivity, but clearly exhibit abnormal connectivity that may vary between different regions. In the autistic brain, high local connectivity and low long-range connectivity may develop concurrently due to problems with synapse pruning or formation. Similarly, neural connectivity patterns that lead to other developmental disorders are not described simply as too many or few neural connections (synapses). Accordingly, some embodiments are directed to estimating changes in neural connectivity in the developing brain using nonlinear techniques as such changes may be used as an effective diagnostic marker for abnormal connectivity development.
[0013] A great deal of information about interrelationships in the nervous system likely remains hidden because the linear analysis techniques currently used to analyze neurobiological data fail to detect these interrelationships. Accordingly, some embodiments are directed to using chaotic signal and phase synchronization analyses of electromagnetic data. Such analyses arose from a need to rigorously describe physical phenomena that exhibited what was formerly thought to be purely stochastic behavior but was then discovered to represent complex, aperiodic yet organized behavior, referred to as self-organized dynamics. The analysis of signal complexity and interaction between signals leading to transient synchronization may reveal information about local neural complexity and long-range communication between brain regions, reflecting the underlying neural connectivity structure.
[0014] Some embodiments have applications related to methods, computer-readable media, and/or computer systems for risk assessment and/or diagnosis of one or more developmental disorders based, at least in part, on complexity and/or synchronization techniques applied to EEG data collected from infants or young children. The quantities computed from EEG data by these various techniques are collectively referred to as EEG ‘signal features’ or ‘feature set’ or simply ‘features’. For example, some embodiments may be directed to:
Using at least one machine learning algorithm to classify a feature set including EEG measurements collected at multiple time intervals; Applying at least one nonlinear method of analyzing the complexity and/or synchronization pattern in EEG signals to identify biomarkers of brain development; Classifying infants into abnormal development or typical development categories using multiscale entropy and phase synchronization determined from EEG measurements; Predicting scores on standardized tests (e.g., Autism Diagnostic Observation Scale (ADOS), Mullen tests) from nonlinear EEG features using supervised learning algorithms; Combining entropy and synchronization features identified in EEG data to extract characteristic patterns of developmental disorders including autism; Determining single growth trajectories or feature vectors for a child by combining nonlinear analyses of EEG data collected at different developmental time points (that is, at different ages, such as 6, 9 and 12 months of age); Mapping generalized synchronization between EEG channels or signals to characterize abnormal brain connectivity in children at high risk to develop autism; Assigning risk for at least one developmental disorder based, at least in part, on classifying, with a supervised machine learning algorithm, patterns in an EEG feature vector; and Monitoring the progress of a therapy provided to children at risk for developing developmental disorders by tracking complexity and/or synchronization measures of EEG data collected at multiple timepoints throughout the therapy.
[0024] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided that such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
[0026] FIG. 1 shows examples of common time series and the corresponding multiscale entropy curves in accordance with some embodiments;
[0027] FIG. 2 is a plot of mean multiscale entropy calculated over all EEG electrodes that shows differences between controls and high-risk children in accordance with some embodiments;
[0028] FIG. 3 is a plot showing the scalp distribution of modified sample entropy for different groups of children in accordance with some embodiments;
[0029] FIG. 4 is a flow chart of an EEG data collection and processing technique in accordance with some embodiments;
[0030] FIG. 5 is a flow chart of a risk classification technique in accordance with some embodiments; and
[0031] FIG. 6 is an exemplary computer system on which some embodiments may be implemented.
DETAILED DESCRIPTION
[0032] Following below are more detailed descriptions of various concepts related to, and inventive embodiments of, methods and apparatus according to the present disclosure for analyzing electromagnetic data. It should be appreciated that various aspects of the subject matter introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the subject matter is not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.
[0033] In some embodiments, electromagnetic data collected from infants or young children may be analyzed using one or more measures of complexity or synchronization. The electromagnetic data may be collected in any suitable way and embodiments are not limited in this respect. Any suitable electromagnetic data may be used in accordance with embodiments including, but not limited to magnetoencephalography (MEG) and EEG.
[0034] In one implementation, resting state EEG using a 64 channel Sensor Net System and signals was recorded using Netstation software available from EGI, Inc. Measurements were taken from a total of 143 infants ranging in age from 6 to 18 months. The distribution of infants in each group (HRA: high-risk for autism, CON: typically developing controls) is illustrated in Table 1. The data were amplified, band-pass filtered (0.1 to 100.0 Hz) and sampled at a frequency of 250 Hz.
[0000]
Age (months)
6
9
12
18
All
# HRA
19
13
31
12
75
# CON
21
13
26
8
68
Total
40
26
57
20
143
[0035] The collected EEG data may be analyzed using one or more of the entropy, complexity and/or synchronization techniques described herein or any other suitable measure of entropy, complexity and/or synchronization and embodiments are not limited in this respect. It should be appreciated that any EEG data may be used in accordance with embodiments of the invention, including, but not limited to, EEG data that was collected for some purpose other than use with the analysis techniques described herein.
[0036] In one embodiment, twenty seconds of continuous EEG data from all channels was used to compute modified sample entropy on multiple scales as follows (See Bosl, et al., 2011 for more details). Multiple scale time series are produced from the original signal using a coarse graining procedure (e.g., see Costa et al. Physical Review, 2005, 71 (2 Pt 1), pp. 021906, the entirety of which is incorporated by reference herein). The scale 1 time series is the original time series. Scale 2 time series is obtained by averaging 2 successive values from the original series. Scale 3 is obtained by averaging every three original values and so on as shown in equation 1.
[0000]
s
1
:
x
1
,
x
2
,
x
3
,
…
,
x
N
s
2
:
(
x
1
+
x
2
)
/
2
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)
/
2
,
(
x
3
+
x
4
)
/
2
,
…
,
(
x
N
-
1
+
x
N
)
/
2
⋮
s
20
:
(
x
1
+
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+
x
20
)
/
20
,
(
x
21
+
…
x
40
)
/
20
,
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,
(
x
N
-
20
+
x
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)
/
20
(
1
)
[0037] Coarse grained series up to scale 20 were computed for each of the 64 EEG channels. The modified sample entropy (mSE) defined in Costa et al. was used to compute the entropy of each time series. The mSE algorithm uses a sigmoidal function to compare vector similarity rather than a Heaviside function with a strict cutoff as with the Sample Entropy sometimes used for analysis of biological and EKG signals. A practical effect of using the modified sample entropy is the computed entropy values are more robust to noise and results are more consistent with short time series.
[0038] The modified multiscale entropy (mMSE) was computed from the EEGs for all infants using the modified multiscale entropy algorithm described above. In brief, the similarity functions A r m and B r m defined by equations (7) and (9) in Costa et al. were computed m=2 and r=0.15 for each coarse-grained time series defined in equation 1 above. The mMSE for scale s with finite length time series is then approximated by:
[0000]
mMSE
(
s
,
m
,
r
)
=
-
ln
(
A
r
m
B
r
m
)
(
2
)
[0039] Examples of mMSE curves for several different time series are shown in FIG. 1 . Note that white noise and the completely deterministic logistic equation have similar multiscale entropy curves. While the EEG time series shown is visually similar to white noise, its mMSE is quite distinct from all of the other mMSE curves shown. Plots in FIG. 1 where entropy decreases when moving from left to right indicate that a signal contains information only on the smallest scale. In general, if the entropy values across all scales for one time series are higher than for another, then the former is more complex or has greater complexity than the latter.
[0040] In order to make some general comparisons of EEG complexity between risk groups and different ages, the mean mMSE was computed as a representative scalar complexity value for each of the 64 channels. Group averages and values for subsets of the 64 EEG channels were computed using equation 2 for infants in the normal control and high risk groups.
[0041] The group average mMSE value versus age for infants in each of the two risk groups is shown in FIG. 2 . The bold black line is the mean MSE value averaged over all 64 EEG channels. Left and right laterality were determined by averaging all left-side and all right-side channels separately. Similarly, mMSE values for four left frontal and four right frontal channels were averaged and plotted versus age.
[0042] Several features are immediately apparent. A general asymmetry in MSE is apparent in both normal and high-risk groups, although this appears to decline from 12 to 18 months as the left and right hemisphere and frontal curves come closer together at 18 months. EEG complexity changes with age, but not uniformly. In the normal controls, the overall EEG complexity, shown by the solid black line 210 , increases from 6 to 9 months, then decreases slightly from 9 to 12 months before increasing again from 12 to 18 months. Left and right channels and the right frontal channels all follow this same pattern, though there is a clear asymmetry between left and right hemisphere complexity. The left frontal channels follow a different pattern, increasing strongly until 12 months, then declining after that. The complexity curve 220 for the high risk group follows a similar pattern, but the overall complexity is lower and the increases and decreases are much more exaggerated. Perhaps even more distinct is the left frontal curve. It follows the same pattern as all other regions but is more accentuated in its decline from 9 to 12 months, unlike the normal controls.
[0043] Since the complexity changes seem to vary with EEG channel, a better picture of complexity changes with age and between risk groups may be observed using a scalp plot.
[0044] FIG. 3 shows all EEG channels by risk group and age. The complexity values here are computed by averaging the mean mMSE over all coarse grain scales for that channel as in FIG. 2 . Complexity variation with age and between risk groups is immediately apparent. One or two channels of the left frontal region appear to increase in complexity continuously with age in the normal controls, as does the right parietal/occipital region. The complexity in the high-risk group is lower than in the control group overall. Although the pattern of complexity change from 6 to 9 months appears similar, the high-risk group shows a marked decline in overall complexity from 9 to 12 months.
[0045] Longitudinal studies that compare the MSE trajectories over each brain region may be helpful to determine if characteristic differences can be found that indicate developmental problems. A potential limitation of the data presented herein is that the high-risk group is expected to be quite heterogenous. In the general population, represented by the normal controls, approximately 1 in 150 children are expected to be diagnosed with an ASD after age 3 . In the high-risk group, the rate is much higher: 10% to 20% of the infants in this group will later be diagnosed with an ASD. It is not known how many of the high-risk infants exhibit endophenotypes or genetic traits that are indicative of some ASD characteristics, even if they are not later diagnosed with ASD.
[0046] The complexity calculations described herein clearly indicate differences between the normal control group and the high-risk group. These complexity differences may reflect endophenotypes (psychiatric biomarkers) that family members may carry even if they do not develop ASD symptoms. Some of the individuals in the high-risk group will develop ASD symptoms of varying severity. The use of EEG signal complexity, as measured by the modified multiscale entropy, may be a sensitive measure of functional brain differences that indicate endophenotypes of ASD or other developmental disorders. As the cohort of children described herein grows older, future EEG measurements, at least through age three years when an official ASD diagnosis can be made, may be informative to compare those in the high-risk group who develop autism from those who do not.
[0047] Biological complexity may reflect a systems' ability to quickly adapt and function in a changing environment. The complexity of EEG signals was found in one study to be associated with the ability to attend to a task and adapt to new cognitive tasks; a significant difference in complexity was found between normal subjects and those with diagnosed schizophrenia. Schizophrenic patients were found to have lower complexity than normal controls in some EEG channels and significantly higher interhemispheric and intrahemispheric cross mutual information values (another measure of signal complexity) than the normal controls.
[0048] The inventor has recognized and appreciated that other measures in addition to signal complexity may be useful in analyzing electromagnetic data collected from infants and young children. For example, while signal complexity is a property of a single time series or EEG channel, transient synchronized activity is a measure of the interaction between different channels and an indication of communication and coordination between different brain regions. Synchronization may be used as a marker for diagnosing underlying mental disorders such as schizophrenia, autism or epilepsy and may also reveal causal mechanisms. The complexity of synchronization patterns appears to change during network development and reflects different neural wiring schemes and levels of cluster organization.
[0049] Additional research is needed to firmly establish the neurophysiological meaning of generalized synchronization between EEG channels. Longitudinal studies to establish baseline synchronization patterns in normal infants at different ages during development and those in people with specific cognitive or mental dysfunctions are needed. A combination of complexity (as measured by, for example, MSE) and generalized synchronization patterns together may give sufficient information about functional brain development to determine if further assessment or early interventions are advised.
[0050] However, even if the neurophysiological mechanisms regarding complexity and/or synchronization measures as good biomarkers for mental function or disease are not well understood, the techniques described herein for mapping electrical brain activity, as measured by electromagnetic sensors, to mental and developmental disease using machine learning are nonetheless applicable for assessing risk and/or early diagnosis of developmental disorders. That is, provided that the electromagnetic signals contain diagnostically distinct patterns that are recognized by one or more machine learning algorithms, diagnosis and/or classification in accordance with embodiments is possible, even though the underlying etiology of the electromagnetic signals may be unknown. This is common in medicine: for example, high cholesterol levels were found to be associated with increased risk for heart disease, even before the physiological mechanisms by which high blood cholesterol causes heart attacks were understood.
[0051] Patterns of synchronization may be useful as biomarkers for developmental disorders if measured regularly during growth. For example, in normal adults, resting state EEGs contain high mid-range (alpha) frequency activity over occipital regions and low activity in other frequency bands. During childhood and adolescence this pattern is quite different and moves toward adult frequency distributions in a linear trajectory. In one study, EEG coherence at shorter distances in children increased through the teen years while long range synchrony did not vary.
[0052] Abnormalities in phase synchronization between multiple bands have been found to be sensitive biomarkers for mental dysfunction in schizophrenic patients. Unfortunately, similar abnormalities in synchronous activity have been found associated with a number of other mental disorders, so further research is required to discover if more refined patterns of synchrony exist for discriminating different disorders or subtypes. A developmental perspective may be useful here. For example, while many attempts to correlate cortical thickness with intelligence have failed, recent research demonstrated that specific characteristic growth trajectories of cortical thickness from infancy to early teen years were highly correlated with above or below average intelligence, suggesting that growth curves of brain function may contain more information than any combination of measurements at one specific age. This may require that routine brain measurements become part of the medical record and algorithms that recognize abnormal trends would need to be used to interpret data after regular cognitive growth checkups.
[0053] It should be emphasized that phase synchronization or signal coherence is an inherently nonlinear phenomenon and is not simple correlation. Three different measures of phase synchronization may be distinguished: coupling between brain regions, synchronization across different frequency bands and phase-locking to external stimuli. Research on the neurological and neuropsychological significance of nonlinear synchronization continues and new methods for detecting multichannel, generalized synchronization and clustering for discovery of mutual synchronization in multichannel data continues. To date, application of multichannel clustering and machine learning methods for discovering synchronization patterns have not been applied to EEG data.
[0054] Synchronization itself can be manifested in different ways in different systems. The n:m cyclic relative phase index ψ 1,2 between two signals, φ 1 (t) and φ 2 (t), at a specific time t is computed over a time interval using a sliding window as:
[0000] ψ 1,2 n,m ( t )=| nφ 1 ( t )− mφ 2 ( t )|,mod 1 (3)
[0055] where φ(t)=arctan(H(y)/y) and H(y) is the Hilbert transform of the time series y. The mod 1 term ensures that significant phase differences will be detected even in the presence of noise-induced phase jumps. In most cases n=m=1 is assumed, though cross correlation of signals with n!=m is also possible (note: !=means ‘not equal’).
[0056] Two signals are defined to be synchronized when ψ 1,2 is less than a specified constant. The particular algorithm for computing synchronization described in (3) is stable for nonstationary data and will detect synchronization without the need to distinguish between noise and chaos.
[0057] In some embodiments, synchronization is determined by computing instantaneous analytic phase and amplitude using Hilbert transforms and search for correlation in each frequency band (6 bands are typically defined for infants) using centered moving averages. This approach finds weak or strong correlations with time lags. For each pair, the relative phase index may be computed and stored in a correlation matrix.
[0058] In some embodiments, synchronization is determined using clustering. In this approach, at each time, some channels may be synchronized and it is assumed that bivariate synchronization is transitive; i.e., if A is synced to B and B is synced to C, then A, B and C are considered to be synchronized and form a synchronized cluster, assuming all pairs are above the threshold. A clustering or unsupervised learning algorithm is applied (e.g., Pycluster: http://bonsai.ims.u-tokyo.ac.jp/%7Emdehoon/software/cluster/index.htm) to all channels at a single (averaged) time segment.
[0059] In some embodiments, synchronization clusters are compared between different age groups. As the brain develops in infants, cognitive milestones may be accompanied by changes in long-range connectivity, which may be reflected in synchronization patterns, forming clusters of different regions/neuronal ensembles.
[0060] Local neural network connectivity undergoes rapid change during early development and this may be reflected in the multiscale complexity and synchronization of EEG signals. Evidence continues to accumulate to support the theory that distant brain regions are integrated into transiently coherent ensembles during information processing tasks. A number of recent studies have demonstrated a link between brain connectivity and complexity or synchronized activity. EEG channel synchronization may provide valuable information about the neural correlates of cognitive processes. Abnormal brain connectivity either locally, regionally, or both may be a root cause of a number of brain disorders and changes in local complexity or synchronous brain oscillations are known to be related to brain connectivity. Early markers for neurological or mental disorders, particularly those with developmental etiologies, may be the growth trajectories of complexity, as measured by MSE and phase or generalized synchronization. More research is needed to determine the underlying physiological causes of the relationship between these measured quantities and cognitive development, though sound theories have been put forth.
[0061] The development of novel EEG sensors with improved resolution, together with new source localization algorithms and methods for computing complexity and synchronization in signals promise continued improvement in the ability to measure subtle variations in brain function. Deeper understanding of the relationship between these neurophysiological processes and cognitive function may yield a new window into the mind and provide clinically useful psychiatric biomarkers.
[0062] An exemplary flow chart for processing EEG data in accordance with some embodiments is shown in FIGS. 4 and 5 . In act 410 , EEG data may be collected using a multichannel EEG headset. These measurements may be performed on different groups of children in different age ranges as described above. For example, EEG data may be collected from infants who are three-months old, six-months old, and nine-months old, as shown in FIG. 4 to determine changes in brain function during a development period of interest. Although only three age groups are illustrated in FIG. 4 , it should be appreciated that different and/or more age groups may be used with embodiments as the embodiments are not so limited.
[0063] After EEG data has been collected, in act 420 , complexity and/or synchronization measures based, at least in part, on the EEG data may be determined using one or more techniques described above or other suitable techniques for determining signal complexity or synchronization of electromagnetic signals. The output of the complexity and/or synchronization analyses may be a feature vector 430 , which characterizes the EEG measures for a particular child or group of children at a specific age. In some embodiments, EEG recordings 410 and subsequent analysis 420 may be performed at different ages and the feature vectors 430 output from each of the analyses 420 may be combined into a complete feature set 440 for the child over a range of ages, for example 3 to 9 months of age. The complete feature set 440 may then be analyzed using machine learning, a pattern classifier, and/or some other suitable technique for finding patterns in the feature set that have been determined to be associated with autism or other disorder by previous analysis to assess a risk of developing a developmental disorder (e.g., ASD) based on the available EEG data recorded up until the latest measurements. Accordingly, the risk assessment may be continually updated each time new EEG recordings for the child are collected and analyzed in accordance with some embodiments of the invention described herein.
[0064] FIG. 5 illustrates a flow chart describing a technique for risk assessment based on a complete feature set 440 . After establishing a complete feature set 440 using complexity and/or synchronization analyses performed a multiple time intervals, growth trajectories 510 may be calculated to characterize how components of the complete feature set 510 change over time. In some embodiments, the growth trajectories 510 may be analyzed and classified rather than or in addition to analyzing feature vectors at single age points. For example, the growth trajectories 510 may be used as input data to pattern classifier 520 to predict expert diagnoses, as described in more detail below.
[0065] In accordance with some embodiments, the complete feature set 440 may be analyzed using machine learning techniques such as pattern classifier 520 to assess a risk that a child will develop one or more developmental disorders. Pattern classifier 520 receives as input the complete feature set 440 and a database 530 of training data. The database 530 may include any suitable information to facilitate the classification process including, but not limited to known EEG measurements and corresponding expert evaluation and diagnosis. Pattern classifier 520 may implement any suitable machine learning or classification technique including, but not limited to, a support vector machine, k-nearest neighbors, decision tree, a naïve Bayesian algorithm and support vector machine (SVM).
[0066] The output of pattern classifier 520 is a risk assessment 540 that details a probability that the child will develop one or more developmental disorders, wherein the probability is based on the complete feature set 440 and the training data stored in database 530 , both of which are provided to pattern classifier 520 . The ability of pattern classifier 520 to accurately predict a risk assessment 540 may depend on the extent to which pattern classifier 520 is adequately trained with a sufficient amount of known data.
[0067] FIG. 6 shows a schematic block diagram of an illustrative computer 600 on which features may be implemented. Only illustrative portions of the computer 600 are identified for purposes of clarity and not to limit aspects of the invention in any way. For example, the computer 600 may include one or more additional volatile or non-volatile memories, one or more additional processors, any other user input devices, and any suitable software or other instructions that may be executed by the computer 600 so as to perform the function described herein. For example, the EEG data may be sent directly from a wireless EEG headset to a smartphone or cell phone and may be relayed directly to the remote computing device 618 .
[0068] In the illustrative embodiment, the computer 600 includes a system bus 610 , to allow communication between a central processing unit 602 , a memory 604 , a video interface 606 , a user input interface 608 , and a network interface 612 . The network interface 612 may be connected via network connection 620 to at least one remote computing device 618 . Peripherals such as a monitor 622 , a keyboard 614 , and a mouse 616 , in addition to other user input/output devices may also be included in the computer system, as the invention is not limited in this respect.
[0069] The methods and apparatus disclosed herein may be applied with respect other mental disorders that may have a developmental component in that brain developments or neural correlates emerge in childhood sometimes long before the cognitive, behavioral, or neurological manifestations are observed. Examples of these types of mental disorders that the disclosed methods and apparatus can be applied to include, but are not limited to, schizophrenia, bipolar disorder, susceptibility to post traumatic stress disorder (PTSD), and Alzheimer's disease.
[0070] The above-described embodiments can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. Such processors may be implemented as integrated circuits, with one or more processors in an integrated circuit component. Through, a processor may be implemented using circuitry in any suitable format.
[0071] Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone or any other suitable portable or fixed electronic device.
[0072] Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible format.
[0073] Such computers may be interconnected by one or more networks in any suitable form, including as a local area network or a wide area network, such as an enterprise network or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks.
[0074] Also, the various methods or processes outlined herein may be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software may be written using any of a number of suitable programming languages and/or programming or scripting tools, and also may be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine.
[0075] In this respect, embodiments may be embodied as a computer readable medium (or multiple computer readable media) (e.g., a computer memory, one or more floppy discs, compact discs (CD), optical discs, digital video disks (DVD), magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other non-transitory, tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments of the invention discussed above. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various aspects of the present invention as discussed above. As used herein, the term “non-transitory computer-readable storage medium” encompasses only a computer-readable medium that can be considered to be a manufacture (i.e., article of manufacture) or a machine.
[0076] The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects of embodiments as discussed above. Additionally, it should be appreciated that according to one aspect of this embodiment, one or more computer programs that when executed perform methods of embodiments need not reside on a single computer or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various embodiments.
[0077] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.
[0078] Also, data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that conveys relationship between the fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationships between data elements.
[0079] Various aspects of embodiments may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.
[0080] Also, embodiments may be embodied as a method, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.
[0081] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.
[0082] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0083] Having thus described at least one illustrative embodiment of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention is limited only as defined in the following claims and the equivalents thereto. | The nonlinear complexity of EEG signals is believed to reflect the scale-free architecture of the neural networks in the brain. Analysis of the complexity and synchronization of EEG signals as described herein provides a quantitative measure for routine monitoring of functional brain development in infants and young children and provide a useful biomarker for detecting functional abnormalities in the brain before the cognitive, behavioral or social manifestations of these brain developments can be observed and measured by standard tests. One or more machine learning algorithms are used to discover relevant patterns in the complexity and synchronization values determined from the EEG data to facilitate risk assessment and/or diagnosis of developmental disorders in infants and young children by predicting cognitive, behavioral and social outcomes of the measured functional brain activity patterns. | 0 |
REFERENCE TO RELATED APPLICATIONS
This application is the United States national stage (under 35 U.S.C. § 371) of International application PCT/EP01/02669, filed Sep. 3, 2001, and claims priority to German patent application DE 200 07 429.6, filed Apr. 22, 2000.
FIELD OF THE INVENTION
The invention relates to a blow mold with mold parts for a stretch blow molding machine or the like, which comprises at least one locking element attached to a first mold part, and at least one counter-element attached to a second mold part. Furthermore, the invention relates to a blow molding machine, particularly for the stretch-blowing of pre-molded blanks, which comprises at least one such blow mold.
BACKGROUND OF THE INVENTION
Such a blow mold and such a blowing machine are known from FR-PS 2 646 802.
Blow molds, in which a pre-molded blank is molded by blowing with overpressure in the interior of the blow mold—that is to say, profiled out—are thereby used for the stretch blowing of pre-molded blanks for plastic bottles. The blow mold can, for example, thereby comprise two mold parts, which are supported in a rotatable manner around a common axis. By rotating around this axis, the mold parts can be sealed shut, so that a hollow cavity, in which a pre-molded blank can be molded by blowing, forms within the interior of the blow mold bounded by the two mold parts.
Since relatively high pressures, such as 40 bar, for example, are used in stretch blowing, it is necessary that both of the mold parts attached in a swivelable manner be able to be locked in their sealed condition, so that they can resist the strong internal pressures.
In accordance with FR-PS 2 646 802, a projection with a penetrating aperture is thereby provided on one lateral end of one of the mold parts, and an additional, vertically displaced projection is attached to the lateral surface of the second mold part that is positioned directly opposite to it in the closed condition, which projection accommodates a pin projecting out vertically, which can be inserted into or protrude out from the aperture in the projection of the first mold part. The locking of the mold parts in the blowing machine is thereby brought about in the manner of a trailer coupling by means of a stroke movement by several pins attached to a common activating bar.
This solution is, in any event, expensive in mechanical terms since, in addition to a horizontal movement—that is to say, a horizontal rotating of the two mold parts for opening and closing, for example—, a vertical movement of the activating bar with the pins is still additionally necessary in order to achieve the locking of the two mold parts by engaging the vertically projecting pins of one mold part in the apertures provided in the other mold part.
In an alternative manner, U.S. Pat. No. 3,601,858 proposes providing an anchor-like locking element on one of the mold parts, which element has areas projecting upwardly or downwardly on its end assigned to the other mold part.
Furthermore, two locking hooks, which are acted on by swivel arms and can be rotated by these swivel arms in such a manner that, in one locking position, they encompass the projecting areas of the anchor element attached to the other mold part so that this is set firmly in its position, are provided on the other mold part. Through the swiveling of the locking hooks around their swivel arms, the contact of the hook with the locking anchor of the other mold part can be ended again, and both of the mold parts can thereby be opened.
In any event, this structure, which involves providing hook-shaped elements with corresponding swivel arms which can be retracted relative to one another, can also only be carried out in relatively expensive mechanical terms.
SUMMARY OF THE INVENTION
Proceeding from this basis, the task of the present invention is to make available a blow mold, as well as to make available a corresponding blow molding machine with such a blow mold as makes a constructionally simple locking of the mold parts possible.
The solution in accordance with the invention provides that the counter-element of the second mold part is a shaft which can, by means of rotation around a longitudinal axis proceeding through the shaft, be rotated between a locking position, in which the blow mold is locked, and an unlocking position, in which the blow mold can be opened, and the shaft has such an external contour that the shaft is, in the locking position, at least partially applied against the locking element and, in the unlocking position, releases the locking element.
This design of the blow mold has the advantage that the locking can be carried out in a constructionally simple manner. A complicated mechanical system, such as was otherwise conventional, can consequently be dispensed with. That is to say, neither the solution of using a lock in the manner of a trailer coupling, with a movement of the locking components in two perpendicular planes, which is known from the French patent publication FR-PS 2 646 802, nor the mechanically complicated solution in accordance with the U.S. Pat. No. 3,601,858, with the use of hooks that are acted upon and rotated by arms configured in a swivelable manner, is necessary.
In comparison with that, the use in accordance with the invention of a shaft which, for locking or unlocking, only needs to be rotated around its longitudinal axis, is mechanically easier to design, and thereby less susceptible to failure and less maintenance-intensive. Moreover, very short switching times result.
The shaft advantageously has at least one recess on its circumferential area which the locking element for opening the blow mold can at least partially move past. In one appropriate configuration of the locking element, it is consequently possible, upon joining the two mold parts together, to slide the locking element past the shaft if the recess is directed towards the locking element moving past, so that the mold parts can be closed.
By rotating the shaft around its longitudinal axis, the area of the recess can thereupon be rotated away from the locking element, and an area of the circumference of the external contour of the shaft that does not have a recess can then be applied against the locking element in such a manner that this can not be slid back. This makes it possible for both mold parts to be closed and locked.
Consequently, in this form of implementation, only the provision of a recess in a shaft is necessary in order to make the locking or the unlocking possible. This is simpler, in constructional terms, than providing a mechanical system or hook which can be moved in two planes and is acted upon by swiveling arms, as was necessary in the known solutions.
In one preferable form of implementation, two shafts, which can each be rotated between the locking and the unlocking position around a longitudinal axis proceeding through them, are attached to the second mold part as counter-elements. Since it is not just one shaft, but instead two shafts, which are present as counter-elements, the securing function—that is to say, the locking function—can be realized in a mechanically more stable manner, since not just one shaft, but instead two shafts, are applied to different areas of the locking element for the purpose of locking, and this can consequently maintain the locking in a more stable manner.
Both of the counter-elements are thereby applied at a distance from one another in such a manner that, in the unlocking position, the locking element can be at least partially guided between both of the shafts and, in the locking position, the contours of the two shafts are at least partially applied against the locking element in such a manner that the blow mold is solidly locked.
It is assumed that both of the shafts have recesses at the same height. If both of the shafts placed at a distance from one another are thereby rotated in such a manner that both recesses are oriented towards one another, then an enlarged intermediary space between both of the shafts can be provided at the level of the recesses. In this case, which corresponds to the unlocking position, a locking element can then be slid through the area of the two recesses of the shafts until both of the mold parts are closed.
For the purpose of locking, the area of the recess can, by rotating the two shafts, be rotated far enough outwardly that they are no longer positioned opposite to one another and the penetrating passage between the two shafts is constricted. If the locking element is thereby configured in such a manner that it is now at least partially applied against the contour of the two shafts, and an area enlarged in width, which was guided through both of the recesses in the unlocking position, can now no longer be slid back between the two shafts, then a locking of the two mold parts can be brought about.
In the case of the presence of two shafts as counter-elements, the locking element is, preferably, configured in an essentially T-shaped manner. This means that the locking element must have an area that is expanded in such a manner that, in the unlocking position, for example, it can be slid past both of the recesses in order to close the mold parts. The expanded area must, at the same time, thereby be wide enough that it can not be slid back through the two shafts if these shafts are rotated into the locking position. This makes a particularly secure locking of mold parts possible.
Furthermore, the blow mold can comprise a device for the synchronous rotation of both of the shafts. This makes it possible, in a simple manner, for the recesses, in both of the shafts, to be rotated inwardly simultaneously in order to be positioned opposite one another, for example, and to create a particularly large free space for carrying out the locking element, or to be rotated outwardly simultaneously, in order for the intermediate space to be constricted to a particularly great degree and for the locking position to thereby be occupied.
In order to rotate the at least one shaft, a gear is to be attached to at least one of the ends of the shaft. A rotation of the shafts can then be brought about in a simple manner by means of a gear mechanism of the type as known per se.
The gear is, preferably, to thereby be brought into engagement with a toothed rack or a gear element in such a manner that, by displacing the toothed rack or by rotating the gear element, the gear, and thereby the shaft, can be rotated around the longitudinal axis proceeding through the shaft. That is to say, in the case of a toothed rack, for example, a rotary movement of the shafts can be produced by means of a back-and-forth movement of the same.
If both of the shafts are in engagement with the same toothed rack or the same gear element, then the synchronous rotation of the two shafts, for example, can be brought about in a mechanical manner without an additional electronic device or the like for adjusting the time of the rotational movements being urgently necessary.
The rotation of the at least one shaft can be automated if a contact switch—which, in the closed condition of the blow mold, comes into contact with an external surface of the locking element—is provided. In this case, the beginning of the locking can be initiated automatically by rotating the shaft(s) if the switch is closed by touching the locking element.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of implementation of the invention are described in further detail in the following with the help of the appended diagrams.
These depict the following:
FIG. 1 : A perspective view of a blow mold in accordance with a first form of implementation of the invention, which comprises two swivelably-supported mold parts with corresponding locking units or counter-elements, as the case may be;
FIG. 2 : A detailed perspective view of the locking device of the blow mold in accordance with FIG. 1 ;
FIG. 3 : A schematic cross-sectional view of the locking device of the blow mold in accordance with FIGS. 1 and 2 , in a plane perpendicular to the longitudinal axis of the shafts, whereby the locking device is located in an unlocking position;
FIG. 4 : A schematic view of the locking device of the blow mold in accordance with FIGS. 1 and 2 , in a plane perpendicular to the longitudinal axis of the shafts, whereby the locking device is located in a locking position;
FIG. 5 : A schematic view of details of a blow mold in accordance with a second form of implementation;
FIG. 6 : A schematic cross-sectional view of a locking device of a blow mold in accordance with a third example of implementation, which represents an unlocking position perpendicular to the longitudinal axis of the shaft; and:
FIG. 7 : The locking device in accordance with FIG. 6 , in a locking position.
DETAILED DESCRIPTION OF THE INVENTION
A first form of implementation of a blow mold in accordance with the invention will be described in the following by means of FIGS. 1 to 4 .
A blow mold, which is used in a stretch blow molding machine of the type as known per se, is identified in FIG. 1 with the reference numeral ( 1 ). The blow mold comprises two mold parts which can rotate around a connecting axis ( 2 ) and serve as a shape support, a first mold part ( 3 ), and a second mold part ( 4 ). Both of the mold parts ( 3 , 4 ) are configured in such a manner that they can, in the closed condition, form an internal hollow cavity ( 5 ) in which, by means of mold inserts; not depicted, a pre-molded blank, also not depicted, is inflated in shape in a stretch blowing process: that is to say, it can be profiled out.
For the purpose of sealing the two mold parts ( 3 , 4 ), these are swiveled around the connecting axis ( 2 ) in such a manner that both of the lateral surfaces ( 6 , 7 ) impact against one another. A partially opened, unlocked condition of the two mold parts ( 3 , 4 ) is thereby depicted in FIG. 1 .
Although not depicted in FIG. 1 , the blow mold ( 1 ) also comprises, in addition to both of the mold parts ( 3 , 4 ) and their mold inserts, a base form and, if necessary, a cover form as well. These elements function in such a manner that, when the blow mold is closed, a high pressure that is sufficient for stretch blowing, such as 40 bar, for example, can be applied in the interior ( 5 ).
Details of the locking device ( 8 ) of the blow mold ( 1 ) can be seen in FIG. 1 and , in particular, in FIG. 2 as well. The locking device ( 8 ) thereby comprises locking elements ( 9 ) and counter-elements ( 10 ). In particular, three individual locking elements ( 9 ) positioned along the longitudinal axis of the blow mold ( 1 )—that is to say, positioned spaced at a distance from top to bottom—are thereby integrally formed with the lateral surface ( 7 ) of the first mold part ( 3 ). These individual locking elements ( 9 ) thereby protrude horizontally from the side wall ( 7 ) and have a cross-section that is shaped in an approximately T-shaped manner in a horizontal plane, whereby the transverse support bar ( 11 ) of this T-shaped locking element ( 9 ) is integrally formed with the end of the locking element ( 9 ) positioned away from the lateral surface ( 7 ), and is wider than the longitudinal support bar ( 12 ) of the same. At the transition between the transverse support bar ( 11 ) and the longitudinal support bar ( 12 ), areas rounded off externally ( 13 ) are formed on the left and on the right.
In the area of the lateral surface ( 6 ) of the second mold part ( 4 ), two vertically-proceeding shafts ( 10 - a, b ) are attached as counter-elements. In the area of the lateral surface ( 6 ), the mold part ( 4 ) thereby comprises individual areas ( 14 ) positioned vertically at a distance and projecting horizontally to the outside. Four such areas ( 14 ) are present in the form of implementation depicted. Two penetrating apertures, through which the shafts ( 10 - a, b ) are placed and supported and, specifically so, in parallel with the connecting axis ( 2 ) and at different distances from the same, are provided in each of these projecting areas ( 14 ).
These penetrating apertures, and thus the shafts ( 10 - a, b ) supported therein, are thereby attached radially at a distance from one another. The shafts ( 10 - a , 10 - b ) are configured equal to one another and have an oblong, essentially cylindrical shape. In the area between two projecting areas ( 14 ), the inserted shafts ( 10 - a , 10 - b ) each have recesses ( 15 ) on the circumferential area; that is to say, in this area of the recesses ( 15 ), the shafts ( 10 - a , 10 - b ) are no longer cylindrical in cross-section, but are instead flattened.
The views of FIGS. 3 and 4 depict sectional planes through one of the locking elements ( 9 ) and both of the shafts ( 10 - a , 10 - b ) in a horizontal plane along the line I—I in accordance with FIG. 1 . The flattened shape of the two shafts ( 10 - a , 10 - b ) in the area of the recesses ( 15 ) is thereby depicted by the solid line, and the essentially cylindrical shape of the two shafts ( 10 - a , 10 - b ) in the areas in which these recesses ( 15 ) are not present is shown with the help of the dotted lines.
Each of the shafts ( 10 - a , 10 - b ) is supported in a rotatable manner around a longitudinal axis proceeding through the center of the cross-section ( 16 - a, b ). The following mechanism is provided for the rotation of the shafts ( 10 - a , 10 - b ) around their corresponding rotational axes ( 16 - a or 16 - b , respectively):
As can be seen in FIG. 2 , in particular, a gear ( 17 ), which forms the lower end of the shaft ( 10 - b ), is attached to the lower side of the second shaft ( 10 - b ). This gear ( 17 ) is attached and supported immediately below the lowest of the four projecting areas ( 14 ) of the partition of the second mold part ( 4 ). This gear ( 17 ) engages with a toothed rack ( 18 ), which is connected with a control unit ( 19 ). This control unit ( 19 ) can be an electromechanical unit or a pneumatic cylinder, for example, into which or out from which the toothed rack ( 18 ) is moved. The control unit ( 19 ) can consequently bring about a back-and-forth movement of the toothed rack ( 18 ). The toothed rack ( 18 ) thereby engages with the gear ( 17 ) in such a manner that a back-and-forth movement of the toothed rack ( 18 ) leads to a rotational movement of the second shaft ( 10 - b ) inserted in the projecting areas ( 14 ), around the longitudinal axis ( 16 - b ) of the said shaft.
A second gear ( 20 ), which is, like the gear ( 17 ), solidly connected with the other shaft ( 10 - b ), is attached to the end of the shaft ( 10 - b ) positioned opposite to the gear ( 17 ), above the uppermost of the projecting areas ( 14 ). This second gear ( 20 ) engages, in turn, with a third gear ( 21 ) that is attached, in approximately the same horizontal plane as the second gear ( 20 ), to the upper end of the other shaft ( 10 - a ). Both of these gears ( 20 , 21 ) engage with one another in such a manner that the rotation of the second gear ( 20 ) leads to a rotation of the third gear ( 21 ) and thereby to a rotation of the shaft ( 10 - a ).
The mechanism for the rotation the two shafts ( 10 - a , 10 - b ) is therefore configured in such a manner that, by means of a back-and-forth movement of the toothed rack ( 18 ), both of the shafts ( 10 - a , 10 - b ) can be synchronously rotated by means of the gears ( 17 , 20 , 21 ) and, specifically so, in opposite directions. It should be noted that, for the sake of greater clarity, the area of the shaft ( 10 - a ) below the third gear ( 21 ) is not depicted in FIG. 2 , in order to be able to better illustrate the structure of the locking element ( 9 ) in this area.
As can be noted, in particular, by means of FIG. 4 , which is explained in still more precise detail in the following, the rounded areas ( 13 ) of the individual locking elements ( 9 ) are formed in such a manner that they approximately correspond to the external contour of the shafts ( 10 - a , 10 - b ) in the area in which no recesses ( 15 ) are present on the circumferential area.
That is to say, since the shafts otherwise have an approximately cylindrical shape, the radius of curvature of these rounded areas ( 13 ) corresponds approximately to the radius of the shafts ( 10 - a , 10 - b ), so that the external contour of the shafts ( 10 - a , 10 - b ) can, in their non-flattened area, be closely applied to these rounded areas ( 13 ) of the corresponding locking element ( 9 ) in the locking position in accordance with FIG. 4 .
Although the locking elements ( 9 ) in accordance with the form of implementation described have, apart from the areas of the recesses ( 15 ), an essentially T-shaped form, and the shafts ( 10 - a , 10 - b ) have an essentially cylindrical cross-section, the present application is not limited to these specific shapes.
That is to say, the shafts ( 10 - a , 10 - b ) could also have any other non-cylindrical shape, such as a polygonal cross-sectional form, for example, as long as they contain recessed areas which make it possible for the area released between the recesses to be somewhat greater than the width of the locking element to be guided through both of the shafts. At the same time, the shaft must thereby be configured in such a manner that, in the locking position in which the recesses are not oriented towards one another, the penetrating passage between the two shafts ( 10 - a , 10 - b ) is so narrow that the wide area ( 11 ) of the locking elements ( 9 ) can not be guided through this intermediary space.
The locking device ( 8 ) additionally comprises a contact switch ( 22 ) which is, in the stated example of the uppermost of the three locking elements, attached in the area of one of the horizontally-spaced locking elements ( 9 ). This contact switch ( 22 ) is thereby attached to the second mold part ( 4 ) in such a manner that the forward lateral external surface, in the area of the portion ( 11 ) of the locking element ( 9 ) that is shaped as a transverse support bar, comes into contact with this contact switch ( 22 ), as depicted in FIG. 2 , if both of the mold parts are closed. Furthermore, a control unit ( 23 ), which is connected with this contact switch ( 22 ) and the control unit ( 19 ) of the toothed rack ( 18 ), is present, which control unit ( 23 ), in the event of the contact of the contact switch ( 22 ) with the locking element ( 9 ) of the toothed rack ( 18 ), moves out far enough that both of the shafts ( 10 - a, b ) are rotated into their locking position.
The blow mold in accordance with the first form of implementation is now used as follows:
In the opened condition of the blow mold, both of the shafts are rotated into the position depicted in FIG. 3 , in which the recesses ( 15 ) are oriented to one another, so that the intermediate space between both of the shafts ( 10 - a , 10 - b ) is enlarged far enough that the broad side—that is to say, the area ( 11 ) of the locking element ( 9 ) that is similar to a transverse bar of the “T”—can be guided through the intermediate space.
A pre-molded blank is now brought from above into the hollow cavity ( 5 ), between the mold inserts, which are not depicted, and a base form (not depicted) and a cover form, which is possibly to be used for the sealing of the lower or upper side of the blow mold, are subsequently moved upwardly or downwardly, as the case may be, and both mold parts ( 3 , 4 ) are swiveled around their connecting axis ( 2 ) onto one another until the lateral surfaces ( 6 , 7 ) come into contact with one another. The individual locking elements ( 9 ) are thereby moved approximately into the direction (A), as depicted in FIG. 3 .
The controlled swiveling movement of both of the mold parts ( 3 , 4 ) is carried out for long enough until the forward side ( 24 ) of one of the locking elements ( 9 ) comes into contact with the contact switch ( 22 ).
In this case, which is illustrated in FIG. 4 , the toothed rack ( 18 ) is moved out over the control unit ( 23 ) by means of the control unit ( 19 ), so that the pinion ( 17 ) engaged with the toothed rack is thereby rotated. With the rotation of the pinion ( 17 ), the second gear ( 20 ) attached to the other end of the shaft ( 10 - b ) also rotates and thereby, in a synchronous manner, the third gear ( 21 ) on the other shaft ( 10 - a ). Both of the shafts ( 10 - a , 10 - b ) are consequently rotated simultaneously through a moving out of the toothed rack ( 18 ).
The control unit ( 19 ) thereby moves the toothed rack ( 18 ) far enough out that both of the shafts ( 10 - a , 10 - b ) are rotated into the locking position depicted in FIG. 4 . In this condition, areas of the cylindrical external contour of the shafts ( 10 - a , 10 - b )—that is to say, areas in which the recesses ( 15 ) are not present—are applied to the rounded areas ( 13 ) of the locking elements ( 9 ). This support leads to the fact that the locking element ( 9 ) is locked in relation to the shafts functioning as counter-elements ( 10 - a , 10 b ), and can not be slid back into the unlocking position depicted in FIG. 3 .
If the blow mold ( 1 ) has been locked in this manner, then the stretch blowing process can be carried out in the manner as known per se. That is to say, the pre-molded blank is, at temperatures from 90 to 100° C., blown out into a bottle through the fact that the pre-molded blank is first drawn in the sealed hollow cavity ( 5 ) by means of a cam-controlled drawing bar, and the bottle is then, in a time-delayed manner, stressed with the pre-blowing pressure (12 to 25 bar). The bottle is then subsequently profiled out with the final blowing pressure of approximately 40 bar, and is cooled off in the blow mold ( 5 ).
After the release of the pressure and the cooling off—that is to say, after the pressure in the interior of the blow mold drops down from a given high value to a lower value—the the control unit ( 19 ) can receive a control impulse, so that it automatically moves the toothed rack ( 18 ) back in again until both of the shafts ( 10 - a , 10 - b ) are again rotated from the locking position depicted in FIG. 4 into the unlocking position depicted in FIG. 3 . The blow mold ( 1 ) can, by swiveling the two mold parts ( 3 , 4 ) around the connecting axis ( 2 ), subsequently be completely opened, and the bottle then removed and conveyed to a transport system.
Details of a second form of implementation of the present invention are presented in FIG. 5 . The construction and manner of operation of this blow mold essentially correspond to FIGS. 1 to 4 . Identical components are designated by the same reference numerals as in the first form of implementation. The schematic view from above illustrates a locking position in which both of the mold parts ( 3 , 4 ) are sealed.
The locking device is, in a manner similar to FIG. 4 , thereby located in the locking position. That is to say, the locking element ( 9 ) is slid, with its frontal area, through the intermediate space between both of the shafts ( 10 - a , 10 - b ), and turns these in such a manner that a portion of their external contours is applied against the rounded areas ( 13 ) of the locking element ( 9 ).
The second form of implementation differs from the first one, in particular, through the fact that the mechanism for the rotation of the two shafts is different. Whereas, in the first form of implementation, a toothed rack ( 18 ) that can be moved back and forth is used for the synchronous rotation of the shafts ( 10 - a , 10 - b ), a toothed segment ( 25 ) is provided for that purpose in the second form of implementation.
This toothed segment ( 25 ) has a toothed external contour ( 26 ) which engages with the gear ( 20 ) attached to the upper end of the shaft ( 10 - b ). The toothed segment ( 25 ) can be swiveled around an axis ( 27 ) by means of an arm, so that the rotation of the external contour ( 26 ) leads to a rotation of the second gear ( 20 ) and thereby of the one shaft ( 10 - b ) and, through the engagement of the second gear ( 20 ) with the third gear ( 21 ), to a synchronous rotation of the other shaft ( 10 - a ) connected with the third gear ( 21 ). The toothed segment ( 25 ) is rigidly connected with a lever ( 31 ) on which a cam roller ( 32 ) is supported in a rotatable manner. This cooperates with a control cam ( 33 ) which is positioned, in a stationary manner, on the blow mold rotating on a circular track and, at defined points of the circular path, either opens or closes the locking device, as the case may be.
Details of a third form of implementation of the present invention are depicted in FIGS. 6 and 7 . Identical components are yet again identified by the same reference numerals. The blow mold in accordance with this third example of implementation differs from both of the preceding ones through the configuration of the locking device.
As can be seen in FIG. 6 , only one shaft ( 10 - c ) is present as a counter-element in this form of implementation, and not two, as in both of the other forms of implementation.
This individual shaft ( 10 - c ) can, in a manner similar to the shaft ( 10 - a ) in the first and second form of implementation, thereby be supported in a rotatable manner in the individual projecting areas ( 14 ) of the second mold part ( 4 ). The locking element ( 9 ) is hereby laterally formed on the frontal surface ( 7 ) of the first mold part ( 3 ) in essentially the shape of an “L”. The longitudinal support bar of this “L”-shaped locking element ( 28 ) is thereby configured in such a manner that, in the area between the rotating shaft ( 10 - c ) and the wall ( 30 ) of the second mold part ( 4 ), it can be guided against this partition ( 30 ) positioned closely between two areas ( 14 ) projecting vertically in a spaced manner if the shaft ( 10 - c ) is rotated into the unlocking position.
This unlocking position, which is depicted in FIG. 6 , is characterized in that, the recess ( 15 ) on the shaft ( 10 - c ) is directed inwardly to the partition ( 30 ) of the mold part ( 4 ), so that the broad area ( 29 )—that is to say, the transverse support bar of the “L”-shaped locking element ( 28 )—can be guided between the partition ( 30 ) and the shaft ( 10 - c ). If both of the mold parts ( 3 , 4 ) are completely closed through the fact that, as depicted in FIG. 7 , both of the frontal surfaces ( 6 and 7 ) come into contact, then the broad forward area ( 29 ) of the locking element ( 28 ) has already been guided past the shaft ( 10 - c ).
In a manner similar to the first two forms of implementation, the shaft ( 10 - c ) can, in this case, also be rotated around its longitudinal axis ( 16 - c ) in an automatic manner, such as by being driven by a stepper motor, from the unlocking position depicted in FIG. 6 into the locking position depicted in FIG. 7 , in the area of the external contour of the shaft ( 10 - c ) which has no recess, being partially supported against the rounded area ( 13 ) between the transverse- and the longitudinal support bar of the “L”-shaped locking element, and a sliding back of the locking element ( 28 ), and thereby of the mold part ( 3 ), is prevented by that means.
The blow molds in accordance with the invention consequently make a locking possible in a particularly simple constructional manner whereby, because of the slight inertia of the shafts ( 10 ) to be rotated, an extremely rapid locking and unlocking is possible with small activation efforts. | A blow mold machine, comprising two lockable mold halves. A locking element is fixed onto one mold half and a shaft with at least one recess is mounted in the other mold half. The shaft can be pivoted between a locking position, in which it lies against the locking element and a release position, in which the locking element can be displaced past the recess. A locking mechanism with a particularly simple construction can thus be achieved. | 1 |
STATEMENT OF GOVERNMENT INTEREST
The conditions under which this invention was made are such as to entitle the Government of the United States under paragraph 1(a) of Executive Order 10096, as represented by the Secretary of the Air Force, to the entire right, title and interest therein, including foreign rights.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to field programmable gate array circuits used in digital circuit design, and in particular, to an architectural design for their implementation on a molecular level.
2. Description of the Prior Art
This description outlines the prior practices in digital systems design and the construction of the gate array forms of integrated circuits.
A wide class of digital circuitry, referred to as clocked-mode (synchronous) digital systems, can be represented in a form shown in FIG. 1 . Any clocked-mode system can be represented as a “block” of combinational logic and a linear array of registers. Combinational logic makes binary (“0” or “1”) decisions based on Boolean functions of binary inputs and is the generalization of combinations of simple logic gates having one or two inputs (e.g., “AND”, “OR”, etc.) to a “block” of potentially many logic gates that inter-relate m inputs and n outputs. Even as a two-input “AND” gate relates a nearly trivial configuration of m=2 inputs and n=1 output, a generalized combinational logic block might have hundreds or more inputs and outputs.
The second part of a clocked-mode digital system, a linear array of registers, is equivalent in this representation to a set of data (“D”) flip-flops with a single, common clock input. The data inputs to the array of registers come from each of the n outputs of the combinational logic block. The outputs of these registers are then either: (1) outputs (y(t)) of the digital circuitry block, or (2) inputs that are “fed” back (quantity of r signals) into the combinational logic block (h(t)). The registers synchronize the overall operation of a clocked-mode digital system by permitting a change in the outputs only in relation to a single clock. This feature of synchronization is important since it is minimizes perturbations, especially in the inputs that are “fed” back into the combinational logic circuitry (eliminating the so-called “race” conditions). This approach to digital design is popular, predictable (easily modeled), and well-suited to automatic design methods, because when exploited properly, it creates circuitry with completely deterministic behavior.
In other digital systems representations and design approaches (referred to as asynchronous digital systems), the need for such synchronization is relaxed, albeit with considerably more involved design and analysis. The class of asynchronous systems can be shown to be the most general digital representation, and clocked-mode representations are a subset of asynchronous systems. In asynchronous systems, the lack of synchronizing/latching structures like registers and flip-flops make designs much more complex, and sometimes the feedback paths that give rise to sequential behavior become sensitive to process and circuit layout particulars that may escape less careful analyses. Mismatches in timing of paths within a circuit can create the well known hazard and “race” conditions where undesired transitions occur based on skewed information delivery to decision points within the circuitry. Most of the present invention is based on a synchronous model, but templates will also be discussed that can support a rich variety of asynchronous interactions as well.
The clocked-mode of representation is the basis of most digital circuitry today, to include finite state machines, micro-sequencers, central processing units, and many custom designs. As most of the automated synthesis of contemporary digital systems designs is based on clocked-mode representations and since many field programmable gate arrays are intended for this mode of operation, this restriction does not significantly limit utility of the present invention. The key restriction to the application of clocked-mode circuitry is the existence of a single “synchronization domain”, i.e., a single common clock controls the actions of the register array.
Very complex circuits contain multiple synchronization domains. It is not uncommon to divide very complex digital designs into synchronous and asynchronous sections, in which cases the synchronous content is usually dominant and lends itself to automatic design approaches. A full discussion of the ad hoc processes for multi-domain and asynchronous digital design are considerably involved and only have referential pertinence to the present invention. It is sufficient to indicate that the core concept of the present invention is based on approaches applicable to a single or a small number of synchronization domain(s) of a complex clocked-mode circuit. Asynchronous circuits can of course be more complex, since the synchronization domains may be ad hoc and in fact may be difficult to ascertain, which is among many of the reasons why asynchronous design is more complex and less represented in automated design approaches.
The role of storage and feedback in digital systems is necessary in order to implement stable and history-dependent behavior in a circuit. Combinational circuitry acts on the immediate values of input variables, which when changed or removed, can create a change in the output function. Changes in an output of a block of combinational logic are therefore subject to variations in the inputs. They are also subject to delays in the time responsiveness of the combinational circuitry itself, a real world effect which is largely due to the speed of signal propagation in circuit elements and the sluggishness of the circuitry to sudden changes (due to, for example, capacitive effects). Since digital systems need to rely on stable information, it is important that a decision based on the output of a combinational block be made after all delay effects have subsided. For this reason, the use of a register array is important, because it represents a snapshot in time of what should be the correct output of the combination circuitry. After the snapshot is taken, the inputs of the preceding combinational circuitry can change without affecting the registered output. Hence, “registered” can be thought of as “registration”, in this case, registration to the edge of a pulsed clock signal. The highest speed at which a synchronous digital circuit can be operated is limited by the frequency of the clock pulses, and this frequency is limited by the longest combinational circuit path. Careful management of the delay effects and knowing when new inputs can be provided to the circuitry and when the clock can be “advanced” are the hallmarks of the present art of high-performance digital design. The registers in clocked-mode circuitry clearly facilitate the stability necessary for achieving this performance. Furthermore, when registers can provide feedback to the combinational network, they permit history-dependent behavior. The registers that are fed back into the combinational circuitry block can be said to encode state information.
Since combinational circuitry generates output(s) based on a Boolean function of one or more (or all) inputs, they can generate the value of, among other things, the value of the next state. Decoupled by the synchronization structure provided through the register array, this state is latched in by the clock to become the “new” (next) state. Finite state machine (FSM) behavior is strictly a manifestation of the existence of state information, hence the use of feedback is necessary for implementing complex digital systems. Generation of both outputs and states is accomplished through the combinational circuitry, and the snapshot of the current, correct outputs and states is accomplished through the register array.
It is important to observe the two extremes under which the combinational part of the synchronous digital system can be implemented. In the first extreme case, a combinational circuit can be represented as a very large look-up table (LUT). Since a combinational circuit with m inputs can be completely specified by truth table of 2 m entries, it is simple conceptually to consider a circuit where all of these entries are contained in an electronic LUT, which is equivalent to a brute force electronic implementation of a truth table. A simple example based on a two-input AND gate is shown in FIG. 2 . In FIG. 2 ( a ), the symbol of the circuit is shown. In FIG. 2 ( b ), the truth table which enumerates each of the 2 2 =4 combinational possibilities is shown. In FIG. 2 ( c ), a brute force matrix implements a look-up table (LUT) based on decoders and a matrix. The decoder is simply a circuit that has an output that is active (“high” or logical state “1”) for only one of each possible combination of the inputs, which is identical to the number of truth table entries (2 m ). The matrix implements the truth table using a brute force approach. The column wire represents the output of the look up table. Here, the presence of a diode between a row and the single column is equivalent to having a logical “1” for the corresponding entry in the truth table. For the AND gate, of course, this condition only occurs when both inputs are high. The diodes are used instead of ordinary wires to prevent shorting through reverse paths, which becomes important for the case where more than one column exists.
It is a simple matter to extend the number of outputs by adding columns. For example, to implement the two function circuit in FIG. 3 ( a ), which is an AND gate in parallel with an OR gate for the same inputs a and b, the circuit in FIG. 2 ( c ), is expanded by adding another column. Of course, this in effect implements both truth tables of FIG. 3 ( b ), resulting in the fmal circuit in FIG. 3 ( c ).
Of course, these illustrative examples are not practical, primarily because the decoding circuitry itself is more complicated than the simplistic target example being shown. It is clear, however, as the approach is extended to more complex examples, that the decoding overhead becomes a less significant fraction of the circuit in question. The primary objective of this discussion is to provide a framework for discussing one extreme in implementing a combinational logic circuit with m inputs and n outputs. In summary, the look-up tables in this context are shown to consist of a decoder circuit for m inputs, and a m×n matrix with diodes representing entries where a logical “1” is present (for the truth table entry corresponding to that particular row and the output corresponding to that particular output) and without any diodes at all where a logic “0” is present.
It is important before examining the other extreme in combinational logic implementation to explore the matrix itself of the look-up table just described. Clearly, this look-up table represents information content, corresponding to a pattern of ones and zeros in number of truth tables (one for each output). In contemporary design, it is possible and normal to use a memory device to implement such information. Hence, a memory device can implement a look-up table. In FIG. 4, two examples of a memory are shown in look-up table applications. In FIG. 4 ( a ), a very simple 16-bit memory (another illustrative but impractical device example) is shown, which has four inputs and a single output. For these examples, the control signals are omitted for clarity. The four input memory is identical to a four-input lookup table, which can notionally be any conceivable Boolean function of four inputs. In one example (FIG. 4 ( b )), a four-input OR gate is represented. A second example using the 16-bit memory, shown in (FIG. 4 ( c )), implements a more complex function, equivalent to several individual combinational logic gates. Considerably more complex fimctions are obviously possible, given the very dense memories available in contemporary integrated circuit design. For example, a semiconductor memory shown in FIG. 4 ( d ), simple by modern standards, contains one megabit (2{circumflex over ( )}20) of storage, which in this form can implement a combinational network of as many as 17 inputs and 8 outputs. This memory can (by definition) implement any eight independent truth tables or Boolean finctions (one for each of the eight outputs) of the same 17 input variables.
It is clear that every technology that has been used to implement a memory can be used to implement a look-up table. Common classes of such semiconductor memory include permanent, read only memory (ROM), programmable (usually fuse-link based) read-only memory (PROM), erasable (otherwise permanent) read-only memory (EPROM, UVPROM, EEPROM, “flash” ROM, etc.), and random-access memory (RAM). ROM and PROM memories and considered “one time programmable”, useful for fixed implementations, but generally un-alterable. RAM-based approaches, on the other hand, can be altered at will (i.e., they are reconfigurable), provided that circuitry for re-configuration is built into the design. These two tenets—re-configurability and the means of re-configuration—are the cornerstones of field programmable gate arrays (FPGA), and these concepts are central certainly to the present invention as they are central to nearly every other existing FPGA.
Although a look-up table (LUT) implemented as memory is a clear and powerful technique for implementing a “block” of combinational logic, the more direct approach is to simply use individual logic gates, wired together as necessary, to form general combination logic networks. Hence, rather than implement the circuit in FIG. 4 ( c ) as a 16-bit memory, the seven discrete logic elements (AND, OR, and inverter or “NOT” gates) would be used. Why use this method, given the conceptual simplicity of memory devices? Several reasons exist, but the simplest justification is derived from the example of a 100-input AND device. The device is conceptually simple, as it is merely a combinational logic circuit with 100 inputs and a single output. The device outputs a logical “1” only when all inputs are equal to logical “1”; otherwise, the output is logical “0”. Implementing this device as a memory is intractable by present standards, as it would require a memory containing 2{circumflex over ( )}100 bits of memory! As a direct implementation, however, it is simple to implement. Even built from elemental 2-input AND gates, this function would require only approximately (N/2)*log 2 (N) (˜50) gates to implement. It is clear that the number of logic gates required to implement a Boolean fuiction varies with its complexity of the function. The number of elemental (e.g. 2- or 3-input) gates needed to implement can be exponentially complex in the very worst case. However, in the vast majority of cases, logic functions for commonly used designs have much less complexity on average than the very worst case. Unfortunately, using a memory to implement logic always results in an exponential amount of circuitry, regardless of what finction is implemented, whether simple or complex.
A compromise between implementing a combinational logic block as an impossibly large but infinitely flexible memory device (serving as a massive LUT) and a large array of direct but inflexible logic devices is the fertile ground from which the field programmable gate array (FPGA) device field has been born. If this argument has a “punch line”, it is that FPGA devices employ the use of many elemental LUTs in an interconnection matrix of wires that can be re-routed to some degree by software. The approach is summarized in FIG. 5 . It seems that “total control” is possible, since both the behavior and connections are controllable. The behavior is controlled by establishing a desired pattern of ones and zeros in the various LUTs, and the connections are controlled by exploiting whatever reconfiguration potential exists in the routing manifold. LUT-based approaches bear attributes in common with both memory-based and gate-based implementation schemes. Since LUTs are in effect a memory, the offer the flexibility of memory. The difference is that in order to implement functions with large numbers of inputs, several LUTs are used instead of one massive memory. If, for example, a 12-input function could be implemented with four, 3-input LUTs, the total number of memory bits is 4*2{circumflex over ( )}3=32 memory bits. On the other hand, with a memory-only approach, a similar implementation necessarily requires 2{circumflex over ( )}12=4,096 memory bits (equivalent to 128, 3-input LUTs). The LUT-based approach achieves dramatic economy in storage requirements over brute-force memory approaches by limiting growth of bits in any single memory (LUT), and then relying on having the ability to apply many such LUTs to implement Boolean functions. In this respect, LUT-based approaches resemble approaches based on using elemental gates. The difference, of course, is that LUTs are capable of implementing any gate with the same number of inputs. There are, however, essentially two compromises in effect: (1) the fine mesh of LUTs can implement any function of only a small number of inputs and may not be able to implement all conceivable Boolean functions of larger numbers of inputs, and (2) the routing interconnection network must necessarily contain compromises that restrict some routing possibilities. The end product then is a sort of emulation of a direct approach in combinational logic using some granularization (no super-large LUTs) into a number of element LUTs with a manifold of interconnections. For RAM-based FPGAs, of course, both the contents of the LUTs and the switch patterns of the routing network are user re-configurable.
Contemporary field programmable gate arrays (FPGAs) are built as monolithic integrated circuits (ICs), usually involving silicon semiconductor technology. The technology of semiconductor fabrication involves a variety of processes that can be divided into high temperature (>600 degrees Celsius) and low temperature (<600 degrees Celsius). The high temperature processes include diffusions and oxidations, while low temperature processes include the metallization (wiring between transistors). Low temperature metallizations must be done after all high-temperature processing is completed. Performing an IC fabrication involves the serial processing of a group of wafers (lot) through many high and low temperature processes.
In the early days of digital ICs, all designs were done based on completely customized layouts of all IC features, including transistors and interconnects. It was later learned that the high temperature steps could be done generically for a large group of wafers, which could be stockpiled. When orders for specific IC devices were needed, these semi-fabricated wafers could be completed by finishing only the last few low-temperature steps, dramatically improved the pace at which customer orders for ICs could be filled. By changing only the last steps of nearly fabricated wafers, it was found that large classes of digital designs could be created by establishing a dense planar grid of transistor diffusions on the surface of a wafer and stockpiling them with undefmed metal layers. To form finalized integrated circuits, it was necessary to specify the metal interconnections between the pre-fabricated diffusions/transistors (through layout). Since the time-consuming and complex task of the transistor fabrication was already done, the simpler design and fabrication steps involving metal interconnections could be done in a very short time. Such devices, referred to as gate arrays, are used to implement complex digital integrated circuits quickly by personalizing the metal interconnections on silicon wafers that contain a large pre-fabricated array of transistors. “Personalization” is an act of design that allows the wafer to be mask-customized for specific functions through the process of integrated circuit layout, which involves a variety of patterning steps through which intentional designs are conveyed during fabrication.
Field programmable gate arrays (FPGAs) carry the analogy of speedy customization of partially fabricated gate arrays one step further. In particular, FPGAs defer the functional specification of its internal circuit configuration until after the chip is built through software. In this case, a designer personalizes (using software only) the configuration of IC “chips” that are completely pre-fabricated and sometimes in the user's own inventory, dramatically reducing the time to achieve a specialized IC as the delay of fabrication is completely eliminated. FPGAs rely on a large number of special pre-fabricated circuit structures that can be configured and connected under software control to form finctions that are in many cases equivalent to those that would otherwise be built with “semi”-prefabricated gate arrays or fully customized designs.
FPGAs can be viewed as devices that predominately contain large numbers of logic and routing “resources.” They can in some sense be viewed as a pool of building blocks that can be configured and connected at will into more complex circuits. Physically, this is not done by adding material (e.g., wires) to the device but by setting and clearing bit patterns in what is referred to as a device configuration memory. The bits of the configuration memory have nothing to do with the device's actual operation, but rather correspond to the specification of a behavior pattern (for logic resources) or the bridging/separation of wiring paths between various points within the device. Configuration memory specifies the operation of the device, just as software specifies the operation of a computer. But whereas a computer is based on blocks of logic and wiring that are fixed, the FPGA creates in effect the appearance of a moldable block of logic and resources. The bridges in physical reality are always present or have the potential of being present nearly everywhere in the device. The design process then for FPGAs is reduced to specifying a particular subset of the potential connections and behaviors necessary to effect a desired deliberate overall circuit. This circuit for almost all intents and purposes performs in a manner indistinguishable from a circuit made in a more traditional way (gate array or fill custom).
The patterns impressed into FPGAs to form circuits can be reversible or permanent, depending on the underlying process used to fabricate the original device. The reversible FPGAs are said to be re-configurable, whereas the permanent FPGAs are said to be “one-time programmable.” Since this invention is concerned only with reversible patterns, only those FPGAs will be discussed further here.
In reversible or re-configurable FPGAs, the configuration pattern that defmes device behavior is usually transmitted electrically into the device upon the initial application of power into the device. In RAM-based FPGAs, the configuration of the FPGA is persistent only for as long as power is applied to the device. Once power is interrupted, the pattern is lost and must be re-established. In practice, this need to re-fresh can be handled in several standard ways, and in fact is often desirable as a feature. Such RAM-based FPGAs can be updated even after a system containing them has been placed in service. In RAM-based FPGAs, logic and routing resources comprise the essential building blocks from which general-purpose digital systems can be made.
The most important concept for implementing logic resources in the FPGA is the look-up table (LUT). A LUT can be viewed as a Boolean function generator of m Boolean input variables. Since m inputs can be formed in 2 m possible ways, it is relatively straightforward to form an m-input LUT with a 2 m -bit memory that has a one-bit wide data path and m address bits. Two possible equivalent implementations of a 3-input look-up table (3-LUT) are shown in FIG. 6 . In the figure, A is the symbol of 3-LUT; B is the K-map representation; C is the implementation using N-pass transistors; and D is the implementation using 2-input logic gates.
LUTs are capable of implementing all 2{circumflex over ( )}(2 m ) possible functions of m variables, and in any sense, the m-LUTs (LUTs with m input variables) are completely capable of simulating/implementing any m-input function.
Since general digital systems must be capable of history-dependent behavior, it is important to implement memory in designs. For many LUT-based designs, a single memory bit is included at the output of each LUT. When implemented as shown in FIG. 7, a memory feature can be optionally incorporated in a LUT. A multiplexer (data selector) allows the use/bypass of a single memory bit (shown in the form of a “data” or “D” flip-flop) when the data selector is set to a “1” or “0” by the state of a single configuration memory bit. When selected, the output of the LUT is registered in synchronization with the clock signal. This establishes the basis for state machine behavior. In this case, the contents of memory comprise the state. When the data selector is bypassed, the output of the LUT is passed directly to the output.
FPGAs also contain routing resources, which are usually in the form of wires and transistor-based switches between those wires. A piece of the routing fabric that might be contained in a typical FPGA is shown in FIG. 8 . In this example, 12 wires (labeled “a” through “l”) and 20 switches (not labeled) are shown. The circle represents a switch as shown in FIG. 8 ( b ). The switch is controlled by a single bit of configuration memory, which shorts together the wires when set to “1”, and otherwise leaves the wires open-connected. Symbolically, an open circle represents an open switch and a filled circle a closed switch. For illustrative purposes, FIG. 8 ( c ) depicts a battery at terminal “a” connected to a light bulb at terminal “f”. As shown in FIG. 8 ( d ), in order to turn on the light, at least two switches must be closed.
It is true today and it will always be likely that FPGAs by their very nature will inferior in performance to devices made using fixed wiring integrated circuits, such as standard cell gate arrays or full custom designs. Here, performance refers to speed and density. This is due to the fact that FPGAs implement much more routing circuitry than an equivalent gate array or full custom IC (which connect metal wires only between intended points on a specific design). Correspondingly, FPGAs are much more sluggish due to excess parasitic capacitance associated with the additional interconnect needed to guarantee the possibility of general connection to many points with possible designs. Another factor in the sluggishness of FPGAs is the extra amount of silicon required to permit reconfiguration. According to DeHon, an FPGA may take 100× silicon area to implement the equivalent function in a fixed-wire, fixed-logic approach (i.e., the standard cell gate array or full custom IC). [DeHon, Andre. “Reconfigurable Architectures for General-Purpose Computing”. Massachusetts Institute of Technology, A.I. Technical Report No. 1586, October 1996]. As such, there is additional propagation delay due to time of flight over a longer distance. Since both the additional capacitance and time of flight are delay factors, the FPGAs are generally incapable of the maximum possible performance in any given silicon technology.
For reasons of performance, modem silicon FPGAs employ structures that at their essence are the same LUTs and routing resources previously described, but far more elaborate. In fact, 80-90% of the silicon area of typical FPGAs are dominated by interconnection-related resources. The embellishments attempt to enhance the performance of FPGAs and improve their generality in application the widest cross section of digital designs that are popular at the time of introduction. In the research of considerably advanced electronics, in which the critical device dimensions are on a nanometer scale, many problems fundamental to device engineering exists. At these dimensions, no effective lithographic techniques exist. Furthermore, interconnection supplies appear to be very constrained. While even at contemporary device scales (180-250 nm) these problems exist, it is still practical to assemble circuits where an individual node might have hundreds of connections. At the nanometer scale, particularly for molecular electronics, it appears possible to converge only a very limited number of electronic connections at a single physical location (e.g., 2-6). Finally, it is likely that many random defects will occur in electronics fabricated at a molecular scale. Only structures that appear to have high regularity are likely to have the ability to recover fimctionality in the presence of such defects. As such, many ordinary architectures designed in silicon, where defect densities are controllable, will be unsuitable for application at a nano-scale, due to interconnection demand.
SUMMARY OF THE INVENTION
The molecular field programmable gate array (MFPGA) is an architectural concept for field programmable gate array (FPGA) circuits that can be implemented in a variety of technologies, e.g., silicon very large scale integration (VLSI), but that would be particularly useful for nanoelectronic/molecular-scale applications. c A “universal” fabric of cells called look-up tables (LUTs) is arranged in a directed, repeatable x, y grid. The grid is called “universal” because the LUTs can implement logic and/or interconnect (interconnect considered as a special case of logic). The FPGA is not especially intended to be as spatially efficient as other silicon-based FPGAs, as this property is compensated for in nano-electronic/molecular-level designs by sheer density of cells. It is likely, however, that some circuit designs will nevertheless have very efficient implementation (i.e., they will map well). By the same token, it is expected that some Boolean fimctions, especially those with high interconnection demand, will not map efficiently into MFPGA-based architectures.
The simple, repeatable pattern of cells is easily tested by setting up temporary programmations of the LUT cells designed to identify and isolate faults and replacing the trial programmations with application-specific “permanent” programmations (“permanent” is a relative term, as programmations can be altered at will.). Since the fabric is intended for very dense implementations, a number of isolated faults can be circumlocuted in software using a robust synthesis procedure. In this manner, the MFPGA is fault tolerant. The basic fabric of the MFPGA is intended to implement combinational functions. To provide complete capability for universal Boolean synthesis, it is necessary to provide sequential storage and feedback. This is accomplished by periodically punctuating the architecture with register vectors. Through careful arrangement of fabric sections and registers, a variety of feedback paths can be established. Input/output to the MFPGA are subject to “cones of influence.” This is an artifact of the intended molecular level implementation, in which it is not possible to attach an electrical terminal to every input/output signal in the MFPGA device. These “cones of influence” are identified for deliberate exploitation in any associated synthesis procedure involving the MFPGA devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general representation of digital systems.
FIG. 2 comprising of FIGS. ( a ), ( b ) and ( c ) shows a typical simple logic gate and how to implement the equivalent finction using a simple (diode-based) memory array.
FIG. 3 comprising of FIGS. ( a ), ( b ) and ( c ) shows an extension of the memory array to handle several finctions of the same input variables.
FIG. 4 comprising of FIGS. ( a ), ( b ), ( c ) and ( d ) provides more examples of memory arrays, illustrating how memories can be equivalent to a look up table (LUT).
FIG. 5 shows how digital logic could be implemented using a number of simple LUTs with an unspecified interconnection fabric.
FIG. 6 shows two implementations of a 3-input look-up table (3-LUT).
FIG. 7 shows a technique for combining storage with look-up tables in an FPGA architecture to create sequential behavior (LUTs only implement combinational behavior).
FIG. 8 comprising of FIGS. ( a ), ( b ), ( c ) and ( d ) is a sample routing fabric for a typical FPGA.
FIG. 9 is a static flip-flop circuit emulation of a single universal, three-input Boolean look-up up table.
FIG. 10 is a k-map representation of three Boolean input variables.
FIG. 11 comprising of FIGS. ( a ), ( b ), ( c ) and ( d ) is a one-dimensional (1-D) binary CA structure that has a neighborhood of three.
FIG. 12 is an example rule for a 1-D binary CA with neighborhood three.
FIG. 13 shows an example of a complete local rule set specification.
FIG. 14 is a three input AND gate with the expected truth table demonstrating the simple correspondence between Boolean functions of m variables and a binary CA of m variables.
FIG. 15 shows other sample Boolean finctions.
FIG. 16 is an array based on 3-input lookup tables or tile.
FIG. 17 comprising of FIGS. ( a ), ( b ) and ( c ) shows the temporal-to-spatial conversion of a 1-D CA into a 2-D structure.
FIG. 18 comprising of FIGS. ( a ) and ( b ) illustrates null and periodic (circular) boundary conditions as applied to 1-D CAs.
FIG. 19 shows to types of dangling bonds in a tile structure.
FIG. 20 comprising of FIGS. ( a ), ( b ), ( c ), ( d ) and ( e ) depicts an example source digital circuit transformed through computer aided design synthesis into an equivalent implementation that only uses 3-LUT building blocks.
FIG. 21 depicts a silicon VLSI implementation of a shift register that relies on a non-overlapping two-phase clock.
FIG. 22 is an example schematic of how a configuration system is connected between each LUT.
FIG. 23 shows the impact of a single defect in the FIG. 22 configuration scheme.
FIG. 24 demonstrates a variation of shift configuration for improved robustness.
FIG. 25 demonstrates a variation of shift configuration for improved robustness when a defect is present.
FIG. 26 shows the use of multiple bitstreams to contain point failures.
FIG. 27 shows two logic array blocks containing m×n LUTs interfaced through a 1-D array of molecular flop-flops.
FIG. 28 shows sample arrangements of LUTs and flip-flops.
FIG. 29 details how a register array can be used to interface two tiles.
FIG. 30 shows how input/output terminals to the system might be interfaced to the LUT blocks.
FIG. 31 is an example of a defect-free logic section.
FIG. 32 is a sample logic section with a single random defect.
FIG. 33 shows how re-mapping can bypass the defect.
FIG. 34 comprising of FIGS. ( a ), ( b ), ( c ), ( d ) and ( e ) is a simple example of a four-cell 1-D CA (with the neighborhood of 3), describing a state transition graph for both the periodic and null boundary cases when the rule # 90 is applied.
FIG. 35 is a symbolic representation of a 3-LUT.
FIG. 36 comprising of FIGS. ( a ) and ( b ) is a 3-LUT tile represented by any arrangement of tesselation symbols.
FIG. 37 is an isometric 3-D physical view of the 3-LUT tesselation symbol.
FIG. 38 shows the dependency arrangement for a 3-LUT using a 3-D version of the tesselation symbol.
FIG. 39 comprising of FIGS. ( a ), and ( b ) shows a possible 5-LUT molecular FPGA cell.
FIG. 40 comprising of FIGS. ( a ), ( b ), and ( c ) is an example of a 2-D MFPGA architecture based on a 4-LUT.
DESCRIPTION OF THE PREFERRED EMBODIMENT
This architecture is comprised of one or more large planar (x, y) arrays, each array consisting of identical building blocks that each implement a single universal, three-input Boolean look-up table (LUT). LUTs are a well-known construct to the designers of VLSI field programmable gate arrays (FPGAs). The m-LUT is designed to implement any possible function of m Boolean input variables. In the case of the 3-LUT, an eight-bit memory (static flip-flop circuits, see FIG. 9) that is programmed serially during initialization is sufficient to represent any Boolean function of three variables (2{circumflex over ( )}=8). By using the three Boolean variables to control of an 8-input multiplexer (built of molecular scale AND, OR, and NOT gates) and storing one bit of an overall pattern in each input location, exactly one bit of the 8-bit pattern is selected. Since all possible input variations are covered by exactly one output, which can be arbitrarily defined, this LUT universally implements any of the 256 possible Boolean functions of three inputs (2{circumflex over ( )}2{circumflex over ( 3)}=256).
It is important to understand the power and flexibility of the LUT, as it enables the construction of a universal computing fabric. A simple Karnaugh map (k-map) representation of three Boolean input variables reveals how eight bits can represent a three-input Boolean function. In the simple example shown in FIG. 10, a Boolean function f=ABC′+ABC+A′BC=AB+BC is represented. The terms ABC′,ABC, and A′BC are called minterms or implicants, and represent the “cover” of ones, or the specific cases where a non-zero behavior results. Clearly, only three cases exist where the function f has the behavior of one. By Boolean algebra, the equation ABC′+ABC+A′BC reduces to a simpler form AB+BC.
A simple analogy can be formed between cellular automata and LUTs. Cellular automata (CA) are simple regular structures that can be thought of as a periodic lattice in space. It is possible to discuss multi-dimensional CAs, but this discussion will presently only focus on one-dimensional CA structures, which can be thought of as a linear array. An individual site is referred to as a cell, and a specific set of one or more cells is referred to as a CA structure. CAs, by virtue of this periodic linear arrangement, are discrete in space. They are also discrete in time, that is, each cell has a value or state that is fixed at each time instant, and time behavior proceeds in discrete intervals. This discussion will further be restricted to binary CA structures, which may only take on the values of “0” or “1” at each cell location.
The behavior of CAs is simple and completely characterized as a function of cells in a neighborhood about each cell in an array. This discussion will focus momentarily on one-dimensional (1-D) binary CA structures that have a neighborhood of three. Such a CA is shown in FIG. 11, with a close-up depicting the neighborhood about a single cell. In FIG. 11, cell B has a neighborhood of three cells, which is defined to include the cell itself (“B”) and its two nearest neighbors (“A” and “C”). (It is equivalent to state that this description is of a 1-D CA with neighborhood radius r=1). In other words, the next state of “B” depends upon (and only upon) the present state values of “A”, “B”, and “C”. In CAs, it is customary that this neighborhood relationship be true of all cells in the CA structure. In other words, all cells have identical neighborhood arrangements, where each cell's next state depends upon only itself and its two nearest neighbors.
The behavior of CAs is completely governed by a set of local rules that prescribe the next state of a cell as a function of a cell's neighborhood. This behavior is customarily indicated upon all cells in a given CA structure. In other words, all cells in a CA obey identical local rules (this restriction will soon be lifted as a fundamental extension of the basic concepts). An example rule for a 1-D binary CA with neighborhood three is shown in FIG. 12 . The cell “B” is shown to have a present state of “1”, and its nearest neighbors “A” and “C” have present states of “0” and “0”. This neighborhood, then, is said to have the state “010”, and a rule can be established for “B” when the neighborhood has this value. The rule shown in FIG. 12 is that when the present neighborhood is “010”, the next state of “B” is “0”. This local rule is based on one possible neighborhood state. Since the CA is binary with neighborhood size of three, then it is possible to completely specify the behavior of the CA with eight (2{circumflex over ( )}3) local rules, corresponding to vertices of the binary state space ofthree variables: “000”, “001”, “010”, “011”, “100”, “101”, “110”, “111”.
An example of a complete local rule set specification is shown in FIG. 13 . Here, all eight local rules are specified. As this rule set is a complete characterization for a 1-D binary CA with neighborhood size 3, it is possible to observe a very compact specification of behavior. Since each neighborhood state corresponds to a single binary digit, it is possible to use a juxtapositional notation involving a binary number of eight digits or positions, with each position corresponding to a particular neighborhood state. In the normal expression of numerals in the binary system, a number such as “1100” corresponds to a compact notation for 1×2 3 +1×2 2 +0×2 1 +0×2 0 , also known as the decimal number “12”. By realizing that the neighborhood states “000” through “111” are equivalent to the decimal numbers 0-7, and using an eight-digit binary representation: r 7 r 6 r 5 r 4 r 3 r 2 r 1 r 0 where each numeral r i represents the rule for a particular neighborhood state i (from the range 0-7), then the entire CA structure can be specified by a single number within the range 0-255. The specification for each r i is given by the value of the rule for the ith neighborhood state. The number is also referred to as a rule, but a global rule, based on this juxtaposed composition of all local rules.
The progression is more easily illustrated than described. In the FIG. 12 example, the entire local rule set is captured as follows: “111”=“1”; “110”=“1”; “101”=“0”; “100”=“0”; “011”=“1”; “010”=“0”; “001”=“0”; and “000”=“0”. Now, exponentiate each rule as a power of two, corresponding to the neighbor state value, and associate this value to the corresponding rule as follows: 2 7 →“1”, 2 6 →“1”, 2 5 →“0”, 2 4 →“0”, 2 3 →“1”,2 2 →“0”,2 1 →“0”,2 0 →“0”. Finally, convert this association to a traditional binary number in a juxtaposed representation in which the exponents are implied: “11001000”, which is equivalent to the decimal number “200”. This number is called the “rule number” or rule (global) of the CA.
Hence, the behavior of any 1-D binary CA with neighborhood size three can be represented as a single number whose value is between 0 (the binary number “00000000”) and 255 (the binary number “11111111”). This numeric “trick” can be easily applied to binary CAs of any neighborhood size. For a CA with neighborhood m, the number of local rules is 2 m , and the corresponding rule is a decimal number between 0 and 2{circumflex over ( )}(2 m ). For m=4, the neighborhood is 4, the number of local rules is 16, and the compressed scalar number (rule number) that uniquely codifies behavior is a decimal between 0 and 65,536 (2{circumflex over ( )}2{circumflex over ( )}4).
Next, we establish a simple correspondence between Boolean functions of m variables and a binary CA of m variables. It is simple enough to say that any Boolean function of m variables identically defines a truth table of m variables that is equivalent to a particular CA of m neighborhood. In a simple example, FIG. 14, a three input AND gate is shown with the expected truth table. By inspection, we observe that this is simply a binary, 1-D CA of neighborhood 3 and rule number =#128. (In the jargon of CAs, this behavior has only one non-trivial local rule, 111 , which in our notational discussion is related to 2 7 =128.). Another way of looking at the analogy between Boolean functions and CAs is that each entry of the truth table is exactly equivalent to one local rule of a CA.
Finally, we relate the m-variable LUT (m-LUT) as a universal CA of neighborhood size m. If any Boolean formula of m variables can be correlated to a particular CA of neighborhood m, then because an LUT can customize each truth table entry, this action is equivalent to being able to customize each (and every) local rule of a CA of neighborhood size m. We propose a simple definition of a universal CA as being a CA whose local rule set can be defined arbitrarily. Any global CA rule can be directly implemented as an LUT whose number of inputs corresponds to the neighborhood size. Therefore, an LUT of m variables defines a universal CA of neighborhood size m.
Using the equivalence of cellular automata and LUTs, the Boolean function of the example in FIG. 10 can be represented by the juxtapositional representation of eight binary digits (e.g., 01001100, 11111101, etc.) where each digit represents the functional outcome of a particular point in “Boolean space.” The eight bits, which completely specify any conceivable 3-input Boolean function (inputs A, B, and C), can also be represented in decimal. In this example, f(A,B,C)=2 3 +2 6 +2 7 =200, which unambiguously specifies f(A,B,C)=AB+BC.
Other sample Boolean functions are shown in FIG. 15 for a 3-input LUT (3-LUT) case. Not only can traditional functions be implemented, but the LUT can also be used to emulate wires. For example to connect input A to the output f, one needs only specify the behavior f(a,b,c)=A=#170. This latter feature is essential to the subsequent discussion on the construction of homogeneous logic arrays that can compute more complex functions.
It is obvious that the examples in FIG. 15 could be expanded for 4-input, 5-input, etc. LUTs. The extension does require extending the numbering system to a higher number of possible functions (2{circumflex over ( )}2{circumflex over ( )}m for m inputs), but follows otherwise directly the same implementational possibilities.
An important and novel feature of the proposed LUT-based computer architecture is in the connection topology, which is based on studies by Wolfram in the propagation of one-dimensional binary cellular automata [Wolfram, Stephen. Cellular Automata and Complexity. Addison-Wesley, New York (1994)]. Here, we extend the concept to circuit connection topologies, resulting in a homogeneous reconfigurable gate array (see FIG. 16 ). This array is based on an x,y arrangement of 3-LUTs, and in principle can be extended to any m-LUT arrangement, where m is an odd integer (e.g., 5,7,etc.). This array is referred to hereafter as a tile of what will later be shown to be a molecular field programmable gate array (MFPGA). As we have established the equivalence between cells in a CA and logic gates, in particular between their most general representations (i.e., the universal CA and the look-up table), then it is a simple matter to relate the topologies of CAs to the topologies of circuit networks. The LUT-based equivalent of the 1-D binary CA is established by “unraveling” the temporal behavior of the CA in a linear grid into a propagating behavior in a two-dimensional mesh. This simple procedure is illustrated in FIG. 17 . Here, the neighborhood of cell “B” (FIG. 17 a ), which provides the feedback to “B” for generating its next state behavior, is broken out into connections that depend on the results of other cells (FIG. 17 b ). As it turns out, these cells are simply identical copies of the 1-D CA, which impresses the state behavior from the last discrete time step onto the current row, which then computes the next state behavior. Similar connections occur for all neighboring cells (FIG. 17 c ).
Rather than directly implement the feedback behavior of 1-D CAs, the 1-D CA network is unfolded or converted spatially into a 2-D feedforward network that is the heart of a molecular field programmable gate array (FIG. 16) structural concept. Descriptively, the architecture is still classified as a 1-D architecture, but this implementation is obviously two-dimensional in space.
Now, we provide a more concise description of the FIG. 16 tile. It is a tile of 3-input LUTs, with a neighborhood template defined as follows: the value of the ith cell of the jth row for the FPGA will depend on the ith, (i−1)th, and (i+1th) cell of the (i−1)th row (j increases in the direction of propagation), this mapping being a direct consequence of the fact that the FPGA architecture of claim 1 maps the temporal feedback dependencies of the corresponding CA 1-D architecture onto a spatial feedforward network.
The tile is large planar (x-column, y-row) tile of identical cells, each cell implementing a single, universal 3-input Boolean look-up table with six non-redundant, non-power terminal connection patterns per LUT, each LUT being allowed to be distinct and individually programmable for a particular logic function or for routing from external inputs or outputs, the last row of periodic LUT tiles being terminated in a linear array of registers, and side coupling being permitted between tiles. The tile contains periodic wire input/output attachments to any side of tile or register array termini, subject to cone of influence effects. As will be discussed further, the reconfigurable nature and regular structure of the FPGA provides a means to test each tile to locate defective LUTs. If defects are found, as will be discussed, the ability to alter behavioral specifications of any LUT in a tile suggests a means for mapping around a finite number of defective LUTs.
Next, we discuss the end cell boundary conditions of the 1-D CA network and the corresponding relationship to the 2-D feedforward analogy in the MFPGA tile. In 1-D CAs, the treatment of the first and last cells can result in different behaviors in the CA over time. According to Pries et al., two cases exist for 1-D CA structures, illustrated in FIG. 18 . In FIG. 18 ( a ), the left neighbor of the first cell and the right neighbor of the last cell are terminated in logical “0”. This case is referred to the null boundary CA case. In FIG. 18 ( b ), on the other hand, the left neighbor of the first cell is connected to the right neighbor of the last cell of the 1-D CA structure. This case is referred to as the periodic (circular) case. [Pries, W. et. al. “Group Properties of Cellular Automata and VLSI Applications”, IEEE Transactions on Computers, volume C-35(12), December 1986.] In the “unraveled 2-D feedforward network “that forms the basis of the molecular FPGA, it is straightforward to implement equivalent cases. It is more useful, however, to further examine the ends of the sides of the MFPGA tiles, as shown in FIG. 19 . Here, in the basic structure of a tile we find that unterminated side ends form the analogy of “dangling bonds”, a feature that becomes useful later in the consideration of a more complete architecture. The “dangling bonds” come in two types. Type “i” (see FIG. 19) “dangling bonds” are uncommitted inputs, whereas type “ii” inputs are uncommitted outputs. These dangling bonds become useful in more complex structures, where the previously uncommitted bonds become intertwined (or no longer dangling), permitting useful couplings of signals from other sources into the tile.
Next, we make a very simple intuitive leap, one that is very difficult to do from the vantage of CA behavioral studies, but is quite simple from the perspective of circuit design. Specifically and simply, by allowing the behavior of each cell (or the definition of each LUT) to be distinct, we can then form a basis for a field programmable gate array. Sometimes, in CA research, this approach is equivalent to what is referred to as “hybrid” or “non-uniform” CA structures. In such structures, distinct rules can be assigned to each CA cell.
The tremendous density of molecular electronics will allow the implementation of arbitrary combinational digital circuits by using standard methods in multilevel logic synthesis and technology mapping, in which complex functions are decomposed into logic building blocks, such as LUTs. Ideally, this procedure translates digital circuitry of nearly arbitrary complexity into a particular equivalent connection of some quantity of LUTs. These computer-aided design processes are standard in the development of FPGAs. In the case of traditional field programmable gate arrays, separate algorithms are used to determine translation of the digital circuits into equivalent LUTs (or other building blocks) and the subsequent routing of signals between inputs and outputs of these blocks. In the new MFPGA, however, there is an intimate relationship between the inputs and outputs of each LUT with respect to the routing of signals. Decisions about routing between LUTs cannot be separated from the geometric placement and definition of contents of each LUT that comprises a circuit definition of interest.
Proper synthesis approaches will produce representations that can be mapped in a relocatable fashion for the MFPGA, if one considers a circuit as being equivalent to a finite number of LUT blocks that can be relocated within a seemingly infinite sea of LUTs. Since all LUTs have identical neighborhood relationships (except for the boundary LUT cells), a cluster of circuitry can be relocated through translation vertically or horizontally within the array, so long as ( a ) the external inputs and outputs to the cluster can be re-routed and ( b ) the configuration pattern or bitstream sequence is compensated for the translation. This process is represent schematically in FIG. 20 . FIG. 20 ( a ) depicts an example source digital circuit, which is transformed through computer aided design synthesis into an equivalent implementation that only uses 3-LUT building blocks. The associated computer aided design processes used to produce FIG. 20 ( b ) from FIG. 20 ( a ) are referred to as logic decomposition and technology mapping. For the MFPGA, this representation does not capture the geometric constraints imposed by the MFPGA approach, and further computer-aided synthesis processes might produce a specific implementation in an MFPGA tile such as that shown in FIG. 20 ( c ). Here, the LUTs within the 3×5 tile are transparent if not used. A cluster of three solid colored LUTs enclosed by dotted lines represent the core implementation of logic from the FIG. 20 ( b ). Since the output of this cluster does not appear at the output of the tile, it is necessary to “extend” the output using another LUT colored with a hatch pattern that serves as a route-only LUT. The route-only LUT simply passes the results of a single input from the previous row in the tile to the next row of the tile.
In the proposed architecture, routing is indistinguishable from logic, which affords new dimensions of flexibility. As this architecture was conceived of for molecular level implementation, the relatively inefficiency of using logic for routing is potentially more than compensated for by the sheer density of LUTs that could be implemented. Two other functionally identical implementations of the same logic cluster within the 3×5 tile are shown in FIGS. 20 ( d )-( e ). These implementations demonstrate the translation principle indicative of the MFPGA approach. In each case, the number of LUTs required to implement the FIG. 20 ( a ) function are the same, but additional LUTs may be sacrificed to provide the necessary routing from external inputs or outputs.
The technique through which this architecture can be configured is referred to with several terms, such as “personalization” or simply “configuration”. The act of installing the personalization, similarly, is called configuration or personalization. In the industry, RAM-based FPGAs are personalized through a serial bitstream, which is a serial sequence of binary information. A crude analogy is that the FPGA is like a blank state, and the bitstream is the “DNA” which gives the particular FPGA its personality. Changing the bitstream (DNA) changes the personality. Similarly the proposed architecture employs bitstreams for configuring or personalizing each LUT, and until personalized, the LUTs will have an indeterminate pattern. The bitstream may in fact be implemented in the present architecture as an internal shift register.
FIG. 21 depicts a silicon VLSI implementation of a shift register that relies on a non-overlapping two-phase clock. It is straightforward to show that the FIG. 21 implements a four-bit shift register through simulation or construction, and many alternative implementations can be conceived. For the proposed architecture, the shift register would implement 2{circumflex over ( )}m bits, where m is the number of inputs. The shift register is easily related to the FIG. 6 implementation of the 3-LUT, by replacing the series of boxes (on the left of FIG. 6 that contain a “1” or “0”) with a shift register structure. FIG. 6 shows a 3-LUT separate from how the “1”s and “0”s are generated. The requirements, then, for each LUT of the proposed architecture are that additional terminals be added to each LUT, consistent with the design of the shift register. For example, a minimum set of termini would likely consist of three termini: (1) shift-in, (2) shift-out, and (3) clock. Such an implementation is suggested in FIG. 9 . If a molecular implementation requires regeneration of the clock, then an additional terminal is required. If furthermore, a multi-phase clock is required in the shift register implementation (two-phase and four-phase clock schemes are popular in VLSI), then accordingly more terminals are needed to implement the configuration facility within each LUT.
The connection of the configuration facility of the proposed architecture is often suppressed in figures for clarity. In FIG. 22, it is shown explicitly in a very simple form. This form may not be the best, however. As shown in FIG. 23, if a single defect occurs on the configuration “path” that meanders through all the LUTs, then the entire tile is render useless. In FIG. 23, the shaded LUTs do not ever get personalized due to the defect. Hence, the entire tile is “dead”. This is easy to see because: (1) all LUTs “downstream” from the defect will never be personalized and (2) no signals can propagate through the unpatternable LUTs.
Two simple improvements greatly improve the robustness of the tile configuration system. The first is to link between LUTs in the direction or axis of propagation, as shown in FIG. 24 . If a defect occurs, as shown in FIG. 25, then at least part of the tile can be functionally recovered. Another improvement to the configuration scheme involves the use of multiple bitstreams, as suggested in FIG. 26 to provide containment zones for failures.
A number of potentially substantial advantages of such an architecture are indicated. It possesses easily iterated structural features (LUTs with a fixed nearest neighbor connection grid) that can be mass created and extended to very large architectures. Even if Pentium computer chips could be built on a nano-scale, the placement and routing of large numbers of special cells in a fixed arrangement may have the consequences of intractability on various scales, including fabrication and computer-aided-design.
Testability is in principle very simple. It will probably be possible to achieve 100% fault coverage by using the homogeneous network itself to perform testing. Special diagnostic programs can be developed to exercise every wire and node of a complex network, with very little guesswork. Contrast this case with nano-scale, full-custom logic, where even with fault-grading and coverage at 99.99%, an unacceptably high number of failures could go undetected.
The architecture could be very forgiving of faults. Similar to hard disk drives, bad locations could be identified and fed to the logic decomposition and technology mapping software. Algorithms and heuristics for mapping around defective cells in FPGAs could be readily adapted, creating a system that could in most cases implement any conceivable function despite a number of failed regions.
Timing within a block of homogeneously interconnected LUTs is absolutely deterministic since every input signal must pass through the same number of LUTs in order to reach an output. Even when side coupling is exploited, the number of LUTs involved in a particular computation is known and timing can be established. This feature is useful in timing analysis of very complex designs.
Extending the general computation fabric involves combining blocks of LUTs with “user” storage and providing input/output terminals. While each LUT is comprised of memory cells (as previously discussed) to store the behavioral pattern corresponding to a Boolean finction, this memory cannot be modified as a by-product of operating the FPGA (only through reconfiguration, which affects many LUTS at once). Hence, registers must minimally be added in the case of 1-D MFPGA, and these registers can be clocked externally (An approach to achieve asynchronous sequential behavior can be directly achieved in 2-D and 3-D CAs through local feedback, as will be discussed later). One example of such an arrangement is shown in FIG. 27 . In this case, two logic array blocks containing m×n LUTs are interfaced through a 1-D array of molecular flip-flops. This arrangement corresponds to the general representation of a combination-sequential digital system (shown to the right of FIG. 27 ). The flip-flop array exploits side coupling to provide state preservation, as needed to synthesize finite state machines. In this model all 1-D flip-flops are synchronized with a common clock and are limited in frequency only by the total delay represented by 2m flip-flops.
Many other arrangements of LUT tiles and flip-flops are possible. FIG. 28 only begins to hint at the possibilities. Any juxtaposition of tiles either forms a larger tile (when the tile directions are the same) or creates a FPGA with path feedback capability (when the directions are opposite in the case of two tiles, or complete a 360 degree “loop” in the case of more than two tiles). If registers are interposed between tiles, then the feedback behavior is synchronous (compatible with automated digital behavior synthesis design tools); otherwise, asynchronous behavior will result. The fact that omitting registers leads to asynchronous behavior is a simple result, since registers permit “registering” event from input to output to coincide with a clock signal. Removing the registers permits the formation of feedback loops, which sometimes are manifested in subtle and complicated ways in the circuit. As such, asynchronous digital design is a more involved discipline, much less common in practice but certainly possible.
So, by allowing multiple tiles to be connected together so that they form within the composite structure (considering all tiles) propagational paths that can feedback within the composite structure, with or without a linear register interposed between the tiles (whereby the former case gives rise to synchronous logic behavior and the latter case giving rise to the more general form of asynchronous logic, which admits the possibilities of race conditions), a general approach to realizing complex digital systems is established. As a minimum, a molecular FPGA architecture is comprised of a single tile of LUTs (m rows and n columns). Even if the outputs of such a minimal FPGA are “registered”, the construction is of limited utility, since the rich behavioral complexity of modem digital systems requires the ability to achieve feedback behavior. Therefore, more useful molecular FPGAs are formed by arranging a number of tiles in patterns that can, as previously suggested, give rise to sequential feedback behavior.
Details of how a linear register arrangement specifically interfaces between two articulating tiles are shown in FIG. 29 . Here, the register “directions” are alternated, permitting signals to be latched and interchanged between tiles. Most significantly, whenever tiles are articulated (brought together), they: (1) may or may not employ a register file (which provides for synchronous state or data storage), and (2) each tile usually has a different propagation direction. As shown in FIG. 27, the two tiles propagate in completely opposite directions. As shown in FIG. 28, the four tiles propagate at 90 degree angles.
In order to obtain feedback behavior, it is necessary to be able to route signals back within the structure. When registers interpose tiles, synchronous feedback is possible. When tiles directly interface without registers, asynchronous feedback is possible. In the latter case, great care must be exercised to avoid race conditions (hazards), but it is possible to exploit additional system possibilities in this manner.
Input/output (I/O) terminals to the system can be interfaced to the LUT blocks (see FIG. 30 ). In nano-scale implementations, the sheer density of LUT columns precludes attaching a wire at every LUT. As such, pads would be attached at a pitch dimension p, selected according to the packaging technology used for the overall system (e.g., 70 μm for wire bonds, etc.). The inability to place contacts at every LUT column creates a “dead zone” situation, in which the inputs or outputs on particular LUTs are inaccessible. This is due to the fact that in the proposed architecture, each LUT can only connect to the first three nearest neighbors of the preceding row. As such, a “cone of influence” defmes the range of interactions possible with LUT arrays from particular points. Algorithmically, these effects are of little consequence to technology mapping software, and it may be easier in the molecular assembly process to simply build those regions in and ignore them in the ensuing implementation of the reconfigurable processing system.
These properties of the MFPGA can result in a situation where the attachment of I/O is furthermore probabilistic in two ways. First, if the I/O attachment misses a desired connection location, and instead the attachment connects to a different source LUT, then through a diagnostic procedure, it will be easily possible to deduce the exact point where the terminal attachment occurs. Briefly, the procedure consists of a sequence of programs fed into the MFPGA which provides for the “geo-location” of termini, so long as the termini can be exercised with patterns. The second facet of robustness for terminal attachment is that it is not necessarily important for I/O to contact a single LUT input. For the very same reasons that the architecture is defect tolerant and easily testable (by feeding into the MFPGA various diagnostic configurations), the MFPGA can, by design, be somewhat indifferent to the exact location of terminals. This feature allows precision in terminal attachment/assembly to be relaxed.
The fault tolerance of the proposed molecular field programmable gate array architecture is easily shown to be a by-product of its regular structure when combined with appropriate design methodologies and Boolean synthesis heuristics. In the simple defect-free logic section example in FIG. 31, a set of five input variables (a, b, c, d, and e) are used to generate four functions (h 1, h2, h3, and h4). Given the likelihood of many single-point fabrication defects, it is important that architectures for nano-scale electronics be robust enough to deal with random defects.
The example logic functions shown perform a variety of Boolean operations on variables (a-e) and generate intermediate results and eventually generate final functions (h1-h4). To illustrate a potentially likely random defect, FIG. 32 shows the impact of a defective LUT in the second row. Based on the cone of influence, most if not all functions dependent on the defective cell are also defective, The consequences to a non-reconfigurable design would be potentially disastrous.
Fortunately, the ability to reconfigure a vast sea of logic/routing resources makes it possible to readily recover from such defects. An example re-mapping is shown in FIG. 33 . In this case, the single defect is circumlocuted and any ill effects can be safely ignored.
The key to surviving fault tolerant conditions in such molecular FPGA would be based on several critical requirements: a large pool of reconfigurable (re-definable) resources; an arrangement of these resources to permit sufficient generality (multiple mappings of same functions); a process to formally identify defects (functional verification); and a set robust Boolean synthesis heuristics to accommodate defects.
The first requirement is met by the present architecture, which is presently the densest proposed reconfigurable system fabric. The second requirement refers to design methodologies based on the proposed universal computation. It will be necessary to provide “wiggle room” in the design space spanned by the present architecture to permit transparent re-mapping of functions, similar to that shown in FIG. 33 . Such constraints are met through design disciplines exercised in the course of utilizing the proposed device. It is envisioned as previously described that an entire reconfigurable “chip” would contain many functional sub-domains containing vast tilings of the proposed LUT block structure. Synthesis (in the Boolean sense) would be a hierarchical procedure whereby any subset of the overall system would be partitioned into a given LUT block structure. If the partition is too tightly constrained (resources are too nearly fully prescribed), then a number of point defects would “break” the synthesis at that level, forcing a larger scale backtracking (re-allocation of functional subsets to LUT blocks). In this sense, the lack of “wiggle room” results in a more protracted synthesis, whereby even higher level allocations would need to be re-visited. Part of the architectural research to be carried out in this program will be to establish such “wiggle room” requirements and the effects of functional congestion on synthesis performance.
The third requirement for fault tolerance is the ability to identify defects. Fortunately, the same regular structure lends itself very well to formal verification of device, block, and subsystem functionality through the development of test programmations. As previously suggested, such a capability can be used to establish 100% functional verification. The technique for establishing functional verification is summarized as follows: an LUT program set of “personalities” is established that convert the behavior of all reachable LUTs into the equivalent of wiring patterns that verify the ability to reach all LUTs in different connection patterns. Several easy techniques are suggested here, and many other possibilities exist. Since LUTs can emulate wire as a specific instance of a Boolean formula, it is possible to verify a wiring pattern that can be evolved or “swept” throughout the device in a way that would uncover defects in transmission due to an malfunctioning LUT. In other words, a broken “virtual wire” is equivalent to the existence of one or more malfunctioning LUTs. Another approach to establish functional verification is to use the LUT array to simulate known behavior patterns of 1-D binary CAs. This method is simple in that the develop of test patterns can be done quickly and any deviation from expected outputs is easily detected. Achieving 100% coverage is based on selecting a minimal set of such patterns that uncover all “stuck-at” and transmission faults. Other forms of testing for pattern stability and pattern sensitivity can be developed from the same principles. Since the FPGA fabric is in principle infinitely reprogrammable, an entire battery of tests could be developed an applied as required to the arrays to establish fimctional verification.
Finally, the Boolean synthesis system must be “geared” to handle (circumlocute) a finite number of defective LUTs and/or LUT blocks. The realization of complex digital functions from specifications, the common mode of development for complex ASICs, requires the nested solution of many non-deterministic polynomial time (NP-complete) problems in order to arrive at viable solutions in a given medium, whether fixed silicon gate arrays or reconfigurable gate arrays. The process of realization, referred to as Boolean synthesis, generally assumes fully functional resources in the medium, which is probably not a realistic assumption for molecular scale devices. It is necessary, therefore, to consider robust synthesis procedures, whereby a number of known defects, particular to individual devices (identified by a pre-test process), are provided as inputs to the specification procedure, just as the specifications themselves are provided. This situation is analogous to the bad block tables associated with hard disk drives in earlier days of personal computing. Given the bad block map, a hard drive could be formatted in such a way as to ignore defects. We indicate here that a similar approach (in principle) can be applied to achieve maximum yield in molecular devices. It is in fact these fault-tolerant characteristics that may make this very type of architecture the most tractable proposed for nanoscale/molecular scale computational electronics.
By virtue of its analogy to CA structures, the present invention can leverage the extensive research base that has emerged to understand and exploit CA behavior. Because simple CA structures can be thoroughly analyzed and yet can display very rich and complex behavior, they have fascinated researchers since their inception (the concept of CA was originally introduced by von Neumann [Das, A. K. et al. “Efficient Characterization of Cellular Automata”, IEE Proceedings - E , vol. 137(1), January 1990.]). For the case of the present invention, the preceding CA research is expected to have benefits to the analysis, characterization, test, and design of circuitry to exploit the CA fabric. For example, in Pries et al, the group properties of CA are examined, in particular the cyclic behavior manifestations when particular CA rules are invoked or when particular arrangements of CAs with null or periodic boundary conditions are invoked. In a simple example of a four-cell 1-D CA (with the neighborhood of 3), Pries et al. described a state transition graph for both the periodic and null boundary cases, when the rule #90 is applied. For this CA, shown in FIG. 34 ( a ) state is encoded as a binary numeral. The case shown in FIG. 34 ( a ) is a periodic-terminated CA, whose state (reading left to right) is “1001”=9. Based on which of the 16 possible states (“0000” through “1111”) this CA is in, the next state of the CA will take on particular values, as shown in the state transition graph in FIG. 34 ( b ). In this particular case (FIG. 34 ( a )), the CA will display a behavior that progressively evolves to a state of “0000” or decimal 0. It is shown that even for the same CA structure with the same initial state (“1001”), that by changing the CA structure termination conditions, a completely different behavior will result. For example in FIG. 34 ( c ), the CA structure is almost exactly the same as the one in FIG. 34 ( a ), except that the CA is null-terminated instead of periodic-terminated. As a result, a cycle-of-three or modulo 3 periodic behavior results. Clearly this CA, if in a different initial state, would display a modulo 6 behavior (in two different ways) or a continuously repeating behavior.
The same behavior for the 1-D CA with four cells and rule #90 is shown in the equivalent MFPGA structure in FIG. 34 ( e ). Here, the temporal-to-spatial conversion is clearly depicted. Whereas in the 1-D CA case, the state evolves over time inside the same cells, in the MFPGA, it is shown that the behavior evolves progressively through the 2-D structure. In other words, the first row of the MFPGA is equivalent to the 1-D CA at time instant 0, the second row is equivalent to the CA at time instant 1, etc. Eventually, the pattern of “1's” and “0's” repeat, due to the fact that the corresponding CA and initial conditions corresponds to this type of behavior (modulo 3).
Even in this narrowly defined instance, CA behavior can be usefully exploited. In test, for example, these state transition graphs swerve as a signature of expected behavior, and it is conceivable that a rich variety of test patterns could be developed from these types of cyclic behavior. For circuit design, these transition graphs are clearly convenient for designing modulo counters and complex pattern generators. Clearly, the possibility of performing modulo arithmetic with CAs was identified by Pries et al., and exploiting this feature in the MFPGA could lead to convenient simplifications in some aspects of algorithms designed to decompose/map circuits into the MFPGA. (Pries et al, “Group Properties of Cellular Automata and Applications”, IEEE Transactions on Computers, Vol. C-35(12), December 1988).
In 1-D CAs, Wolfram identified the ability to directly emulate linear feedback shift registers (LFSRs), which have many possible roles in design. One such application for LFSRs, identified by C. L. Chen, in is test pattern generation (C. L. Chen, “Linear Dependencies in Linear Feedback Shift Registers”, IEEE Transactions On Computers , C-35(12), December 1986). Also, the use of CAs explicitly for pseudo-random number generators was identified by Tsalides et al (Tsalides et al, Pseudorandom Number Generators for VLSI Systems based on Linear Cellular Automata, IEE Proceedings - E , vol. 138(4), July 1991). In both of these applications of CA to VLSI design, the CAs were not spatially unraveled, as is the case of the present invention, nor is a look up table approach used. Rather than use LUTs, logic corresponding to the specific CA rule is hard-wired in these applications. Obviously, the present invention can exploit these applications as a degenerate subset of their potential capabilities. Das et al also made the connection between CAs and LFSRs and their use for constructing self-test structures (Das et.al., “Built-in Self-Test Structures around Cellular Automata and Counters”, IEE Proceedings - E , vol 137 (4), July 1990). Chang et al. evaluated the use of so-called maximum length cellular automata for stream ciphers and claim that CAs can in a VLSI implementation be realized more efficiently than equivalent LFSR-based implementations. In this case, each CA rule may be distinct. (Chang et al., “Maximum Length Cellular Automaton Sequences and Its Application”, Signal Processing 56 (1997).).
These findings suggest the potential of a dual benefit for the present invention. The first benefit is the ability to use a CA-inspired approach as a general digital implementation fabric. The second benefit is that in those cases where the nature of CA behavior is advantageous, the present invention is uniquely able to exploit that relationship. This suggests the possible improvement in automated design software to recognize those parts of a complex design amenable to a FPGA-based view and those parts amenable to a CA-based view.
Other research findings have pointed to the possibility of using a CA basis for FPGA architecture. Chatopadhyay et al. suggests the use of a specific cell design inspired by two specific CA rules (#90 and #150). Though this research effort identified the potential of a time-to-space transformation, similar to that suggested for the present invention, it only unfolds one stage. Thus, remarkably, the research did not identify the benefits of universal CA realization and a more extensive depth of spatial unraveling. Chatopadhyay et al. also proposes a more complex fundamental cell (5-input, 3-output) than that in the present invention. Most significantly, this effort did not employ LUTs at all, but rely on decomposition heuristics to map a given Boolean (digital) problem into logic based on a non-simple cell comprised of a hybridization of elemental CAs based on rules #90 and #150. Even so, the research is intriguing in that it suggests that a CA-inspired FPGA may be competitive with traditional FPGAs developed by the industry, which of course are not CA-inspired (Chatopadhyay, S. e al. “Technology Mapping on a Multi-Output Logic Module Built Around Cellular Automata Array for a new FPGA Architecture”, 8 th International Conference on VLSI Design , January 1995.)
We are now in a position, having defined a basis of a MFPGA around a very simple CA, to discuss more systematic extensions. The extensions include definitions of MFPGAs for two- and three-dimensional CA architectures. A convenient simplification of the 3-LUT representation is shown in FIG. 35 . This may be called a “tesselation symbol”. With the new representation, a 3-LUT tile is represented by any arrangement of tesselation symbols where: (1) at least one square edge is perfectly aligned to a square edge of a neighbor and (2) the direction of the arrows are the same. Since this juxtaposition is always possible, the term “tesselation” is appropriate descriptive of the symbol. Two examples are shown in FIG. 36 .
In FIG. 36 ( a ), a very simple arrangement of four LUTs is shown. This arrangement is called a “dependency arrangement” because the forward-most 3-LUT has another LUT in each position bearing upon its functional dependence. In other words, the 3-LUT that is at the bottom of the figure can implement any function that depends on (and only on) the other 3-LUTs above it. In FIG. 36 ( b ), an example of a very small tile containing 8×5 (40) 3-LUTs is shown. It is expected that in molecular implementations, much larger tiles (several thousand rows and columns) could conceivably be implemented.
Next, we provide a slight variation of the 3-LUT tesselation symbol, in which an isometric 3-D physical view is provided (FIG. 37 ). Even though this isometric view of a 3-LUT tesselation symbol appears physically to be a 3-dimensional block, the FPGA is said to be one-dimensional, since the results propagate in one-direction only.
We next show the dependency arrangement for a 3-LUT using this 3-D version of the tesselation symbol in FIG. 38 .
This development motivates the consideration of other tesselation symbols, and the progression of symbolic representations will be shown now to lend itself to representing a more complex and powerful possibility. Not to be illustrated are simple extensions of the previously developed (FIG. 16) 1-D CA architectures to 5-input LUT or 7-input LUT templates, as these are fairly obvious. It should be remarked that such templates will be more complicated to actually implement, especially with respect to the side-coupling structures.
The next demonstration of the tessellation will describe a 2-D CA architecture that is actually three-dimensional in its physical implementation. In this case, we employ a 5-LUT that is more easily shown in a 3-dimensional representation. Using the same basic concepts developed above, we shown a 5-LUT tesselation symbol and corresponding dependency arrangement in FIG. 39 . Again, this 5-LUT design, though represented in three dimensions, is fact still a two-dimensional architecture, based on its directional confinement. Unlike other two-dimensional CA architectures, however, localized feedback is not possible with the FIG. 38 architecture.
For two-dimensional physical implementations, most of the previous considerations apply, especially those pertaining to the introduction of user storage and programming the tiles. For three-dimensional implementations, such as FIG. 39, however, it is necessary to expand these concepts. In 3-D FPGA implementations, “tiles” become “blocks” and linear array structures (such as registers) become “tiles”. In general, the concepts hold otherwise. Hence, three-dimensional FPGA blocks can be interfaced on any surface, as opposed to an edge. The blocks may terminate into a register tile (vice array). Blocks may be juxtaposed to form more complex architectures. Configuration bit streams are generated in a similar manner. The “cones of influence” now truly resemble 3-D cones.
Now, we provide a more concise description of the FPGA architecture in FIG. 38 . This architectures is based on a 3-D array (block) comprised of a plurality of LUTs arranged in a directed, repeatable (x-column, y-row, z-level) structure that propagates in the positive y direction, each LUT having only periodic nearest neighbor connections to other LUTs with the tile patterned after a CA neighborhood arrangements (neighborhood radius r=1) and not any other bridging structures except at the boundaries, the definition of each LUT being allowed to be distinct and individually programmable for a particular logic function or for routing from external inputs or outputs, the last row of periodic LUT tiles being terminated in a linear array of registers, and edge coupling (edge corresponds to the first or last row, column, or level plane) being permitted between blocks (by allowing all LUTs to take on the same behavior, the tile directly models a 2-D non-hybrid CA as a degenerate case). This FPGA block may have periodic wire input/output attachments to any edge surface of block or register tile termini, subject to cone of influence effects. This FPGA possesses a means through the introduction of diagnostic test programs to test each block to locate defective LUTs. If cells within a block have datapath-related defects, the FPGA has means for mapping around a finite number of defective LUTs by remapping the functions affected onto good cells and ignoring the defective zone(s). The means exist to combine LUT blocks with user storage in the form of a tile of registers which interface the block at one or more edge surfaces. In the FIG. 38 case, it is possible to connect one or more LUT blocks together at interfacing surfaces. When blocks have coincident propagation directions no feedback is possible, and for the most part, the blocks simply act as a larger single block. When each block has a direction of propagation different from any block adjacent to it, feedback behavior may be possible, giving rise to complex digital systems behavior. If register planes are placed between such surfaces, synchronous behavior results. Otherwise, asynchronous behavior will be possible. Though more involved, a means can be readily established to program the blocks through serial bitstream patterns that are shifted through each LUT in succession using dedicated termini on each LUT, as a minimum containing a shift-in and a shift out with the possibility of one or more clocking signals to “drive” the shifting these patterns through the block. The reliabilty of a block due to potential defects in the bitstream shifting structures within and between LUTs can be improved by propagating the shift patterns through LUTs in the direction of block propagation and by using multiple serial streams, so that single point defects will not result in the loss of an entire block.
A more complex but straight-forward extension to two dimensions is shown in FIG. 40 using symbolic representations. In FIG. 40 ( a ), a basic symbol is shown for a two-dimensional architecture based on a 4-input LUT (4-LUT) in which a center node can implement any Boolean function of its north, east, west, and south (“NEWS”) neighbors. Such neighborhoods are referred to as “Manhattan”, by association of grid-like Cartesian directions. This construction is commonly used in finite difference modeling grids, as well as very popular 2-D cellular automata referred to as the “game of life”. The symbol is slightly modified in FIG. 40 ( b ) to form a tesselation pattern, and a dependency arrangement is shown in FIG. 40 ( c ). An important basic difference in strict CA definitions of a 2-D CA of neighborhood radius r=1 is that the cell itself is excluded from the neighborhood. The MFPGA implementations typically exclude a particular LUT from its own neighborhood to preclude oscillatory instability. When neighborhood definitions are such that a signal can form a loop, however, such feedback can still occur, which is an important consequence of a final class of MFPGA architectures.
A significant consequence on non-unidirectional architectures with dimensionality higher than one is the existence of strong coupling in the form of local feedback. Based on previous discussions, the existence of loop paths for signals within the CA structure creates feedback and therefore sequential behavior. Since this “prescription” of FPGA does not allow user storage to be embedded with the tile (register arrays are only permitted on the edges of a tile), then the sequential behavior is by definition asynchronous. It is possible to form oscillators and achieve a great number of manifestations of asynchronous behavior. As such, it may be necessary to incorporate additional circuitry, such as a global reset to control the behavior of errant configurations.
Another important consequence of non-directional architectures is the elimination of the “cones of influence”. As such, the defect tolerance potential of the associated MFPGA architectures is further enhanced, as is the expressive range of Boolean implementations.
Now, a more concise description of the architecture of FIG. 40 can be developed. This architecture contains one or arrays, each array containing of one or more cells of LUTs arranged in a directed, repeatable column, row (x, y) grid, the array being referred to as a tile, and each LUT having only periodic nearest neighbor connections to other LUTs with the tile patterned after specific 2-D CA “NEWS” (north, east, west, and south) neighborhood arrangements (neighborhood radius r=1, for example referring to the first NEWS nearest neighborhood set, neighborhood radius r=2, referring to the first and second nearest neighbors, and so on) and not any other bridging structures except at the boundaries, the definition of each LUT being allowed to be distinct and individually programmable for a particular logic function or for routing from external inputs or outputs, the last row of periodic LUT tiles being terminated in a linear array of registers, and side coupling being permitted between tiles (by allowing all LUTs to take on the same behavior, the tile directly models a 2-D non-hybrid CA as a degenerate case). This architecture permits periodic wire input/output attachments to any side of tile or register array termini, subject to the limits of neighborhood propagation effects. As before, a means exists to test each tile to locate defective LUTs through application of diagnostic programs, and a means for mapping around a finite number of defective LUTs through fimctional mapping can be applied. The concepts of storage are more involved. Not only are the “traditional” edge linear register arrays possible with this particular tile concept, but localized feedback within the 2-D tile could theoretically be exploited. So,with the inherent tightly coupled feedback loops within the tile structure is the possibility of race (hazard) conditions unless care in design is exercised. As before, the means exist to program the tiles through serial bitstream patterns that are shifted through each LUT in succession using dedicated termini on each LUT, as a minimum containing a shift-in and a shift out with the possibility of one or more clocking signals to “drive” the shifting these patterns through the tile. As before, the means to improve the reliability of a tile due to potential defects in the bitstream shifting structures within and between LUTs by propagating the shift patterns through LUTs by using multiple serial streams, so that single point defects will not result in the loss of an entire tile.
Finally, an important observation of the molecular FPGA as a class of architectural concepts is that they can be implemented in many different processes. Though inspired by and designed for implementations at a molecular scale, they can be implemented at larger scales in many different processes. The only essential implementation requirements are the existence of a complete binary logic system, a memory storage element, and an interconnection system. As such, these concepts can be rendered in conventional silicon and gallium arsenide and other semiconductor process technologies. They can be built in quantum dots (a nanoscale device concept) and other nanoscale/molecular process concepts. Cells, tiles, and entire architectures can be readily simulated, analyzed, and optimized based on application, process, and associated performance boundary conditions. If synchronous digital approaches can be employed, the present concept can directly leverage the substantial existing base on automated digital design tools. Its ability to achieve asynchronous and cellular automata behaviors hint of possibly more significant potential, although at present the disciplines for design in these “domains” are not as well established. | An architectural concept for field programmable gate array circuits is presented based on a universal fabric of cells called look-up tables arranged in a direct, repeatable spatial grid. It is predicated upon an analogy between Boolean functions and cellular automata wherein an m-variable look-up table defines a universal cellular automata of neighborhood size m. Its unique features include universal implementation of Boolean functions, low interconnect demand, no specialized routing resources, high regularity (periodic structures), fault tolerance, and ease in testability. | 8 |
PURPOSE OF THE INVENTION
[0001] The present invention relates to a solar energy collection device, which makes a beneficial change to the tiles of an existing roof or by making a roof that comprises them, either curved or mixed, in such a way that said tiles, besides fulfilling their classic function as covering elements against the effects of the wind and weather, particularly against rainwater, act as solar energy collection devices to heat a thermal transmission fluid.
[0002] The purpose of the invention is to achieve a high performance energy installation that does not alter the aesthetic configuration of the roof on which it is incorporated, both in relation to the actual means of collection and particularly the means of energy transmission.
[0003] The invention also concerns the particularly suitable mounting procedure of the different elements that take part in the installation of this heat transfer system under the tiles, completely protecting this latter.
[0004] The invention, therefore, is situated in the industrial setting of manufacturing devices and equipment for solar energy collection at a domestic level or similar and, as a result, associated to the mechanical or artisan tile manufacture industry.
BACKGROUND OF THE INVENTION
[0005] As is currently known and to collect solar energy at a domestic level, solar panels placed on sloping roofs are generally used. These panels incorporate a metal frame by which they are fixed to the roof, usually raised, with visible and uncovered liquid circulation tubes, sometimes even including the hot water cylinder, therefore it is necessary to make holes in the tiles and the rest of the roof to be able to connect the aforementioned tubing with the interior circuit.
[0006] This brings with it very considerable damage to the aesthetics of the architectural assembly over which the thermal solar panels are mounted, particularly when, as often happens, the surface and the panel colour and its visible accessories have absolutely nothing to do with the characteristics of the existing roof, particularly when it is a roof based on curved or mixed tiles, so common particularly in areas where solar radiation is abundant as well those situated below latitude 50° north.
[0007] To this aesthetic problem also has to be added the problems of corrosion that occur in the elements of these types of panels in the open air when the installations are situated near a marine environment.
DESCRIPTION OF THE INVENTION
[0008] The invention fully satisfactorily resolves the previously explained problem, and from this it converts a traditional roof composed of curved or mixed conventional tiles into a similar and aesthetic configured surface, but which incorporates a device composed of different solar energy collection modules.
[0009] Thus, the device comprises the following basic elements:
A four sided irregular body with a parabolic cylinder able to be attached to the vacuum filled receiver tiles in their interior space. A means of returning and concentrating the solar radiation. A heat exchanger adapted to the lower length of the energy collection device. A heat transfer fluid channelling tube that allows it to be installed without connection components below the tiles. A support cradle which facilitates the hermetic anchor of the heat exchanger to the heat transfer tube achieving optimum thermal use.
[0015] Additionally and depending on the type of roof that it is intended to adapt, it will alternatively contain one of the following elements:
A parabolic cylinder reflector assembly in a lower position and a parabolic cylinder assembly in an upper position that returns the radiation in a cone concentrator. Or a parabolic cylinder reflector assembly in a lower position and an absorbent concentrator in the shape of an corrugated fin, together with the parabolic cylinder in an upper position.
[0018] For this each tile is fitted with an opening or window in its curved sector in which a collection device itself is attached, comprising a body which establishes upper surface continuity with the external face of the tile and which occupies the centre of the same. Inside the aforementioned transparent body two parabolic reflectors in symmetrical positions are situated on the lower end of its wall. Opposite these and centrally located on the focal line also includes a radiation return parabolic cylinder reflector over some concentrator parabolic cylinder laminates connected to the heat exchanger that hermetically receives the heat transfer tube which is situated below all the tiles of an alignment.
[0019] A support cradle of the same length as the body of each device is positioned below the aforementioned tube, with the purpose of positioning and hermetically sealing the aforementioned tube. This cradle positioned over the bellows lifting device allows in the first place to fasten the transparent body by means of spring clips attached to the aforementioned body and which are built in to the side plug holes of the cradle and which in a second advantageous function, ensure the hermetic and heat sealing of the heat transfer tube to the heat exchanger.
[0020] The bellows lifting device provided with its positioning slots or the means (special tool) of aligning and freeing the leaf spring, in its variation they allow, by downward manual pressure applied on the irregular transparent body, this to be connected to the support cradle hermetically sealing the heat transfer tube. This installation procedure similarly offers the greater advantage of achieving a solid assembly between the three elements that make up the tile, the irregular transparent body and the heat transfer tube, being able in this way to adequately support the thermal expansions of the roof in its assembly.
[0021] The irregular transparent body is provided with a connexion for a heat sensor which transmits the recorded temperatures to the device that generally controls the heat exchanger and the hot water distribution system.
[0022] In accordance with an alternative embodiment of the invention, the irregular and closed body instead of being integrated in the tile is independent of this latter, similarly poking through the opening of the aforementioned tile, which makes it unnecessary to make a perfect adjustment over this latter, having been anticipated that to maintain the water tightness of the roof the tile opening is closed with a transparent dome, physically independent of aforementioned closed body.
[0023] It has also been anticipated that the tube for transporting the heat transfer fluid passes through the inside part of the aforementioned hermetic body, improving its arrangement.
[0024] In this alternative embodiment, from the ends of the closed body emerge pairs of support tracks for fixing the elastic clips through which the fixing of the body with the interior components to the support cradle is carried out and the fixing to the wooden battens or concrete base over which the tile sits.
[0025] It is also possible to substitute the aforementioned reflectors, for a shaped lamina covered with a selective coating for absorbing heat, soldered to the corresponding heat exchanger, in which the heat transfer tube is built in lengthwise, enclosed within the transfer chamber, and aligned and hermetically sealed at its ends with the cradle.
[0026] Lastly, it has also been foreseen that the closed body rests on the corresponding cradle supported by a sheet adapted to its lower cylindrical half, based on a reflecting and isolating compound to return the rays to the absorbent sheets and in fact to return and retain the heat for its maximum use.
DESCRIPTION OF THE FIGURES
[0027] To complete the description that is now being made and with the purpose of helping to better understand the characteristics of the invention, in accordance with a preferred practical embodiment example of the same, is attached as an integral part of said description, a set of figures in which for illustrative purposes but not limited to it, the following has been represented:
[0028] FIG. 1 .—Shows a cross-sectional detail of the body or solar energy collection module destined to be integrated into a tile, which takes part in the device of the invention.
[0029] FIG. 2 .—Shows, also according to a cross-sectional schematic representation, a pair of mixed tiles, duly fastened together, to one of which appears opposite the corresponding body or solar collection module, while the other appears duly mounted over the aforementioned module.
[0030] FIG. 3 .—Shows a detail in side elevation and in a lengthwise section of the mounted assembly represented in FIG. 1 .
[0031] FIG. 4 .—Shows a side elevation view and in a lengthwise section of an assembly similar to that in FIG. 2 , in which two tiles appear duly fastened together lengthwise, to the body or collection model itself fastened to the same, and the other to the aforementioned module in an opposite position.
[0032] FIGS. 5 , 6 and 7 .—Show representations similar to those of FIGS. 1 , 2 and 3 , but in which the solar energy collection device appears mounted on curved tiles, instead of over mixed tiles with the support cradle adapted to this type of tile and its special means of fixing.
[0033] FIG. 8 ,—Shows a schematic representation plan view and cross-section of the special tool or the means that are an integral part of the procedure for fixing the irregular transparent body to the support cradle.
[0034] FIG. 9 .—Shows a schematic detail in plan view of several tiles positioned with reference to FIG. 2 .
[0035] FIG. 10 .—Shows, a representation similar to that of FIG. 9 but with the tiles as shown in FIG. 6 .
[0036] FIG. 11 .—Shows, according to a representation similar to that of FIG. 1 , a cross-sectional detail and in partial blow-up of the device according to an alternative embodiment foreseen for the same.
[0037] FIG. 12 .—Shows a perspective blow-up view of the glass tube that passes through the collector with the heat exchanger and the support cradle and alignment, of the previous figure.
[0038] FIG. 13 .—Shows the assembly of FIG. 11 duly mounted and fastened to a tile.
[0039] FIG. 14 .—Shows a side elevation view of the assembly represented in FIG. 11 .
[0040] FIG. 15 .—Shows another side elevation view of the assembly of FIG. 11 , mounted in position over the support structure of the roof.
[0041] FIGS. 16 and 17 .—Show representations similar to those of FIGS. 11 , 12 and 13 , corresponding to another alternative embodiment of the device, for fixing below a tile with a minimum curve radius and reduced height or on a corrugated roof sheet.
[0042] FIG. 18 .—Shows on a sloped roof another view in a side elevation of a series of collectors of the assembly in FIG. 11 , in line and mounted in position over the support structure of the roof.
[0043] FIG. 19 .—Shows, finally, a detail of two types of tiles to which this alternative embodiment of the invention is applicable.
PREFERRED EMBODIMENT OF THE INVENTION
[0044] On looking at the figures described and in particular FIG. 1 , it can be seen that the device of the invention relates to use of an irregular and closed body ( 1 ), preferably of glass, or at least with its upper and external side transparent, smoked or tinted in which comprises four parabolic cylinders and in which particularly the upper side has the same curvature as the tile to which it is destined, as will be seen later on. This closed body ( 1 ), which has been vacuum filled, incorporates in the lower part two cylindrical parabolic reflectors ( 2 ) and, positioned in a focal line and situated above a radiation return cylindrical parabolic receiver ( 3 ) over laminates cylindrical parabolic funnel ( 4 ) concentrators, the radiation channelling being over a semi-cylindrical heat exchanger ( 5 ) coated with a selective absorbent and in which a fixing laminate in the interior side of the irregular tube provides the contact ( 9 ) for a classic temperature control probe.
[0045] Anchored on both sided of the lower faces of the irregular body ( 1 ) are situated spring clips ( 8 ) which are positioned to be easily and simply fastened or fixed by pressure into the plug holes foreseen for this purpose in a support cradle ( 7 ).
[0046] This support cradle ( 7 ) serves to position and hermetically fix a heat transfer tube ( 6 ) against an existing semi-cylindrical hole in the heat exchanger ( 5 ), relying for this purpose on the support cradle ( 7 ) with a cavity ( 11 ) also semi-cylindrical, which completes that which has just been mentioned, to tightly hold the heat transfer tube ( 6 ). The cradle support ( 7 ) is also provided with plug holes ( 10 ) on its side edges for the spring clips ( 8 ) fixed to the body ( 1 ), and lengthwise grooves on its base ( 12 ) to adjust a bellows lifting device ( 16 ) destined to be situated below the tiles ( 14 ) and which ensures that the heat transfer tube ( 6 ) remains perfectly fitted in its cavity ( 11 ).
[0047] In FIGS. 2 to 4 the vacuum filled irregular body, with it different accessories, has been referenced with ( 13 ) and is destined to be fastened to each tile ( 14 ) in an opening ( 15 ) effectively made in the same, as is seen particularly in FIG. 2 . The support cradle shown in FIG. 2 with ( 7 A) is aligned and positioned by the bellows lifting device now shown in ( 16 ), which supports over the roof ( 17 ), or the roof structure that is being used, the aforementioned bellows lifting device being retracted to position ( 16 B), an optimum positioning of the heat transfer tube ( 6 ) having been made previously. In FIG. 2 the assembly comprising the irregular body ( 13 ) enclosed in the tile ( 14 ) and the support cradle ( 7 ) with the tube ( 6 ) has been referenced with ( 20 ), forming a hermetically sealed group or assembly that has been referenced with ( 18 ).
[0048] When it is a mixed tile, as in the case of FIGS. 1 to 4 and 9 , and depending on the width of the same, its flat and side part can be used to place many photovoltaic cells ( 19 ).
[0049] The device shown in a longitudinal section, as is represented in FIG. 3 , indicates the parabolic cylinder geometric shapes of the sides of the complete irregular tube ( 13 A), hermetically fixed to the cradle support ( 18 A) by the spring clips ( 8 ), keeping the heat transfer tube ( 6 ) lengthwise and hermetically fixed against the heat exchanger ( 5 ) in the cavity defined for this latter. The aligning and positioning lifting device is shown both in a theoretical locking position and in a release position, the first referenced with ( 16 A) and the second with ( 16 B) in FIG. 3 .
[0050] A way of carrying out the procedure appears in FIG. 4 , according to which, and in chronological order, a curved and schematised tile, referenced as a whole by ( 15 B), incorporates an opening or window suitable for fitting a complete irregular body ( 13 B) into it, and is positioned over the line symbolising the theoretical slope of a roof panel or roof ( 21 ). The lifting device ( 16 A) is placed at a suitable level and remains locked to ensure that the spring clips ( 8 ) are fastened using pressure to the cradle support ( 7 A) encircling the plug holes ( 10 ) of the same. The complete irregular body ( 13 B) situated above the opening envisaged for this event ( 15 B) is introduced into its housing, in such a way that manual pressure applied over the aforementioned irregular body ( 13 B), according to the corresponding arrow of FIG. ( 4 ) hermetically fastens it to the cradle support encircling the heat transfer tube. The lifting device previously set in the rest position ( 16 B) is shifted below the following tile in a longitudinal line to allow another installation if required. In FIG. 4 the reference ( 22 ) shows the previously finished assembly with the lifting device having been moved ( 16 B). Operating in a loop, the heat transfer tube ( 6 B) is placed below the tile ( 14 ) and, without connectors along the whole length required for the installation to provide a determined number of devices in a line, crossing below the roof again (See reference 6 C), with the aim of being connected to a collector which feeds the domestic heating system, not represented in the figures.
[0051] In the alternative embodiment of the device shown in FIG. 5 , the irregular body ( 23 ) is made under a more taut parabolic cylinder arch, to be able to fit into another curved tile model, that shown in FIG. 6 . In this alternative embodiment and taking into account the reduced internal space, the components are adapted to achieve the same purpose. In accordance with the invention two parabolic cylinder reflectors ( 24 ) are placed inside and in a lower position and, positioned on a focal line in a position above a corrugated fin ( 25 ) of a parabolic cylinder shape, coated with a selective absorbent. The fin is soldered to a concentrator tube containing a heat transfer ( 26 ). The absorbent finned tube ( 25 - 26 ) is fastened with heat transfer connectors ( 27 ), soldered onto a semi-cylindrical heat exchanger ( 28 ) so that a fastening clip in the side of the irregular body ( 23 ) offers the contact ( 30 ) for the heat control probe. Many spring clips ( 31 ) are fixed on both sides of the lower part of the irregular body ( 23 ), duly positioned to encircle the plug holes, provided for the purpose in the support cradle ( 32 ). The support cradle positions and hermetically fastens the heat transfer tube ( 29 ) in the semi-cylindrical hole ( 28 ) of the heat exchanger. The cradle support ( 32 ) is preferably made of the same material and a configuration similar to the support cradle ( 7 ), with similar plug holes for the spring clips and a cavity to house the heat transfer tube. In a variation, the support cradle ( 32 ) is provided with a cavity ( 34 ) to enclose the locking plate ( 35 ) around the axis ( 33 ) in a resting position ( 35 A), having been pushed into its cavity ( 34 ) by the positioning element ( 36 ).
[0052] In FIG. 6 a section has been illustrated where the couplers are on a theoretical line of the sheet or base or roof ( 39 ), where the vacuum filled irregular body and all its elements appear referenced with ( 23 A) and is positioned above the opening ( 38 ) made for the purpose in a tile of the type which appear in the aforementioned figure in an inverted position and referenced with ( 37 ). Reference ( 40 ) shows an assembly positioned with a cradle support ( 32 A) fitted together by the pressure previously applied on the lock plate ( 35 ), while reference ( 41 ) shows the same assembly placed in the opening, the positioning element ( 36 ) having been extracted and the lock plate ( 35 A) being turned and enclosed in the cavity ( 34 ), by the action of the positioning element ( 36 ) depending on its longitudinal displacement applied by the same as shown by the arrow in FIG. 8 . In this way the device integrated into a curved tile is mounted in a typical configuration of positioning curved tiles.
[0053] The parabolic cylindrical geometrical figures of the sides of the irregular body (now 23 B) are shown in the longitudinal section in FIG. 7 , hermetically fixed to the cradle support (now 32 B). The heat transfer tube ( 29 ) is hermetically and longitudinally enclosed in the cavity ( 28 ) of the heat exchanger. The lock plates ( 35 A) are turned on the axis ( 33 ) in a resting position in the cavity ( 34 ) reserved for this purpose. The contact ( 30 ) remains accessible to connect the heat control probe to an automatic control device (not represented) by a connecting cable along the tube ( 29 ).
[0054] Putting into operation uses a special mechanical positioning means or tool ( 36 ), as shown in FIG. 8 by means of a schematic plan and in a partial sectional view. In chronological and sequential order of putting the procedure in operation, using this special tool (now 36 B and 36 C) or mechanical means of positioning adapted to the lock plate ( 35 ) and the support cradle ( 32 A), the aligning tool ( 36 B) is placed below the support cradle ( 32 A) and positioned below the tile opening, the lock plate being in position ( 35 ) retained by a stop dowel ( 42 ), which enables the device to be invisibly fastened ensuring a simple connection of the system. The longitudinal section of this FIG. 8 shows the mode ( 36 D) and the dowel ( 42 A) over the same section. Due to the freeing action shown by the arrow, the lock plate ( 35 A) turns around the axis ( 33 ) to be positioned in its cavity ( 34 ) and be put in a resting position. The dowel ( 42 ) remains free and the positioning device ( 36 ) is withdrawn to carry out a new installation. If required, the device ( 13 - 23 A) is withdrawn from the tile by means of simple traction by means of using a suction pad applied over the dome of the device, the spring clips ( 8 ) and ( 13 ) being less flexible than the lock plate ( 35 ).
[0055] In accordance with the structure described any expert in the art can adapt the positioning device for the working of the invention depending on the type of roof surface support, and depending on the existing tile, or to install the device model which will be used for this embodiment. Also, it has to be understood that the invention is not limited to the embodiment described and there many advantageous adaptations that can be added to these latter ones without being outside the limits of the present invention.
[0056] For example, it can be adapted to the configuration and geometric form of the device and reverse the illustrated internal and external elements to which they are connected, to make a device that incorporates a combination of two or more support tiles or fix in as series of support tiles adapting the shape and the length of the device of the invention, without being outside the limits of the invention.
[0057] FIG. 9 illustrates, according to a plan view, an example ( 44 ) of traditional mixed curved overlapping tiles in which the device ( 45 ) is incorporated and the positioning of the photovoltaic cells ( 46 ) in the flat part of the tiles, while the schematised reference ( 43 ) is side fastened between a normal tile and a modified tile. In FIG. 10 the overlapping of four curved tiles has been referenced ( 47 ) in which the second device ( 48 ) is incorporated, that is to say the second practical embodiment of the invention, which corresponds to the geometric configuration of these types of tiles, where the reference ( 49 ) represents a tile in a gutter position.
[0058] As explained previously, an alternative embodiment of the device appears in FIGS. 11 and 15 , in which there is also a vacuum filled transparent and closed glass body ( 101 ) and a preferred elliptical section, inside which and affecting the upper half of the same, that which is going to be directly benefit by solar radiation through the opening ( 102 ) of the tile ( 103 ) in which has been placed, a shaped lamina ( 104 ) covered with a selective coating for absorbing heat, connected to a specific heat exchanger ( 105 ), preferably of copper, which is set in or soldered in the hole suitable for the glass tube ( 106 ), this same being soldered onto both external faces of the collector it passes through, thus constituting an internal heat transfer chamber ( 107 ), hermetically sealed at its ends by an aligning cradle ( 108 ) fitting of the heat transfer tube ( 109 ) to the heat exchanger ( 105 ).
[0059] The hermetic body ( 101 ) in its lower parabolic cylindrical side is covered by a laminate ( 110 ) based on a compound, including a radiation reflector to return the rays and an isolating felt to prevent heat losses, this assembly being supported and aligned on a support cradle ( 111 ), this latter seated on a cross-section ( 113 ) with levelling, aligning and support functions of the hermetic tube ( 101 ).
[0060] The fixing of these elements is carried out using a pair of supports ( 114 ) which protrude from the ends of the hermetic body ( 101 ) and over which it is destined to support a spring clip ( 115 ) with elastic binding, configured in a “U” shape ( 116 ),to be fitted into the lateral grooves of the support cradle ( 111 ), and with fixing bolts ( 117 ) that, along with the screws ( 118 ), to enable to regulate or adjust the height of the assembly, as is particularly observed in FIG. 13 .
[0061] As is also inferred from looking at FIG. 13 , with the described structure the collector itself is physically independent of the tile ( 103 ), in such a way that it is nor affected by any type of irregularity there could be in this latter, even enabling it to be used with different types of tiles that have the opening ( 102 ), which is closed using a transparent dome ( 119 ), which provides the tile with the due water tightness.
[0062] In accordance with the alternative embodiment of FIGS. 16 and 17 , in which the basic structural characteristics described are maintained, the shaped heat absorbent laminates ( 104 ′) can adopt a different position in the hermetic body, and the different configuration of the supports ( 114 ′) for the spring clips ( 115 ′), reduced in size to fasten to the support cradles ( 120 ) configured to be adapted to the glass tube ( 106 ′) which passes through the hermetic body ( 101 ′) as observed in FIGS. 16 and 17 , in turn being passed through by the heat transfer fluid circulation tube ( 109 ), hermetically sealed and aligned at its ends by the cradles ( 108 ), this mounted assembly being supported by a support frame ( 121 ) which has the function of aligning and adjusting to install it under tiles ( 103 ) of a particular size or reduced curvature with a dome of different shapes ( 122 ) or for corrugated roof panels.
[0063] As explained previously, in this embodiment and apart from the modifications just mentioned, it keeps the same structure as in the embodiment of FIGS. 11 to 15 . | The device part of the embodiment over the tiles ( 14 ) with wide openings( 15 ) which mainly involves, openings ( 15 ) in which are houses both irregular bodies ( 1 - 13 ), of transparent glass, hermetically closed and vacuum filled, which establish surface continuity through the upper face with the rest of the tile ( 14 ) and in whose interior are established parabolic cylinder reflectors ( 2 - 3 ) which conduct solar radiation to a concentration funnel ( 5 ) which defines a semi-cylindrical channel and adapting to the heat transfer tube ( 6 ), which rests over a support cradle ( 7 ) which in turn is pressed against aforementioned tube ( 6 ) by a bellows lifting device ( 16 ), also keeping the support cradle ( 7 ) and irregular bodies ( 1 ) fixed using anchor elements ( 8 ). Thus simple mounting of the collection devices is achieved by a simple pressure coupling system, achieving close contact with the heat transfer tubes which remain hidden and protected below the tiles. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage filing under 35 U.S.C. 371 of International Application PCT/US02/04887, filed Feb. 20, 2002, which claims priority from U.S. Application Ser. No. 60/269,832, filed Feb. 20, 2001, the specifications of each of which are incorporated by reference herein. International Application PCT/US02/04887 was published under PCT Article 21(2) in English.
FIELD OF THE INVENTION
This invention relates to systems and methods for selectively blocking nerve activity in animals, including humans, e.g., to reduce the incidence or intensity of muscle spasms, treat spacticity, or for pain reduction.
BACKGROUND OF THE INVENTION
Spinal cord injury can lead to uncontrolled muscle spasms. Spasticity can also occur as a result of stroke, cerebral palsy and multiple sclerosis. Peripheral nerve injury can cause pain, such as neuroma pain.
Various nerve blocking techniques have been proposed or tried to treat spasms, spacticity, and pain. They have met with varying degree of success. Problems have been encountered, such as damage and destruction to the nerve, and the inability to achieve a differentiation of nerve blocking effects among large and small nerve fibers in a whole nerve.
SUMMARY OF THE INVENTION
The invention provides systems and methods for blocking nerve impulses using an implanted electrode located near, on, or in a nerve region. A specific waveform is used that causes the nerve membrane to become incapable of transmitting an action potential. The effect is immediately and completely reversible. The waveform has a low amplitude and can be charge balanced, with a high likelihood of being safe to the nerve for chronic conditions. It is possible to selectively block larger (motor) nerve fibers within a mixed nerve, while allowing sensory information to travel through unaffected nerve fibers.
The applications for a complete non-destructive nerve block are many. A partial or complete block of motor fiber activity can be used for the reduction of spasms in spinal cord injury, and for the reduction of spasticity in stroke, cerebral palsy and multiple sclerosis. A complete block of sensory input, including pain information, can be used as a method for pain reduction in peripheral nerve injury, such as neuroma pain. A partial or complete block of motor fiber activity could also be used in the treatment of Tourette's Syndrome.
Other features and advantages of the inventions are set forth in the following specification and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is block diagram of a system that serves to generate a waveform that stimulates a targeted nerve region to cause either a partial or complete block of motor nerve fiber activity;
FIG. 2 is block diagram of an alternative embodiment of a system that serves to generate a waveform that stimulates a targeted nerve region to cause either a partial or complete block of motor nerve fiber activity;
FIG. 3 is an enlarged view of a pulse controller that can be used in association with the system shown in FIG. 1 or FIG. 2 , the pulse controller including a microprocessor that generates the desired stimulation waveform;
FIG. 4 is a graph showing the shape of the stimulation waveform that embodies features of the invention, which is constant current and delivered through at electrode near the nerve and comprises a depolarizing cathodic pulse for blocking nerve conduction immediately followed by an anodic pulse;
FIG. 5 is a diagram depicting the presumed action of the voltage controlled sodium ion gates during propagation of an action potential along a nerve. The top trace shows the transmembrane potential and the bottom trace shows the activity of the sodium gates during the same time period. The action potential begins when the m gates, which have a fast response time, open completely. The h gates, which respond more slowly, begin to close, which begins to restore the transmembrane potential. As the potential decreases, the m gates close and the h gates return to their resting position (partially open);
FIG. 6 is a diagram showing the action of the depolarizing waveform shown in FIG. 4 , which is also shown in FIG. 6 below the upper graph, on the nerve membrane dynamics. The first cathodic, pulse causes the h gate to close and the m gate to open slightly. The anodic phase, which is shorter in duration, causes the m gate to return to the fully open state, but the h gate, because it responds more slowly, does not return completely to its resting value. As subsequent pulses are delivered, the h gate progressively closes, which causes the membrane to become inactivated. When the h gate is sufficiently closed, the nerve membrane can no longer conduct an action potential; and
FIG. 7 is a diagram depicting the progressive block of two different nerve fiber diameters, the larger fiber responding to the lower amplitude depolarizing pulse (shown in the lower half of the diagram). The h gate is closed by this waveform and the large nerve fiber becomes inactive. The stimulus amplitude can then be increased so that inactivation of the smaller fiber can take place.
The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fail within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The various aspects of the invention will be described in connection with providing nerve stimulation to cause the blocking of the transmission of action potentials along a nerve. That is because the features and advantages that arise due to the invention are well suited to this purpose. Still, it should be appreciated that the various aspects of the invention can be applied to achieve other objectives as well.
I. System Overview
FIG. 1 shows a system 10 that makes possible the stimulation of a targeted nerve region N to cause either a partial or complete block of motor nerve fiber activity, which is non-destructive and immediately reversible. In use, the system 10 generates and distributes specific electrical stimulus waveforms to one or more targeted nerve regions N. The stimulation causes a blocking of the transmission of action potentials in the targeted nerve region N. The stimulation can be achieved by application of the waveforms near, on, or in nerve region, using, e.g., using a nerve cuff electrode, or a nerve hook electrode, or an intramuscular electrode, or a surface electrode on a muscle or on the skin near a nerve region.
The system 10 comprises basic functional components including (i) a control signal source 12 ; (ii) a pulse controller 14 ; (iii) a pulse transmitter 16 ; (iv) a receiver/stimulator 18 ; (v) one or more electrical leads 20 ; and (vi) one or more electrodes 22 .
As assembled and arranged in FIG. 1 , the control signal source 12 functions to generate an output, typically in response to some volitional action by a patient, e.g., by a remote control switching device, reed switch, or push buttons on the controller 14 itself. Alternatively, the control signal source 12 can comprise myoelectric surface electrodes applied to a skin surface, that, e.g., would detect an impeding spasm based upon preestablished criteria, and automatically generate an output without a volitional act by a patient.
In response to the output, the pulse controller 14 functions according to preprogrammed rules or algorithms, to generate a prescribed electrical stimulus waveform, which is shown in FIG. 4 .
The pulse transmitter 18 functions to transmit the prescribed electrical stimulus waveform, as well as an electrical operating potential, to the receiver/stimulator 18 . The receiver/stimulator 18 functions to distribute the waveform, through the leads 20 to the one or more electrodes 22 . The one or more electrodes 22 store electrical energy from the electrical operating potential and function to apply the electrical signal waveform to the targeted nerve region, causing the desired inhibition of activity in the nerve fibers.
The basic functional components can be constructed and arranged in various ways. In a representative implementation, some of the components, e.g., the control signal source 12 , the pulse controller 14 , and the pulse transmitter 16 comprise external units manipulated outside the body. In this implementation, the other components, e.g., the receiver/stimulator 18 , the leads 20 , and the electrodes 22 comprise, implanted units placed under the skin within the body. In this arrangement, the pulse transmitter 16 can take the form of a transmitting coil, which is secured to a skin surface over the receiver/stimulator 18 , e.g., by tape. The pulse transmitter 16 transmits the waveform and power through the skin to the receiver/stimulator 18 in the form of radio frequency carrier waves. Because the implanted receiver/stimulator 18 receives power from the external pulse controller 14 through the external pulse transmitter 16 , the implanted receiver/stimulator 18 requires no dedicated battery power source, and therefore has no finite lifetime.
A representative example of this implementation (used to accomplish functional electrical stimulation to perform a prosthetic finger-grasp function) can be found is in Peckham et al U.S. Pat. No. 5,167,229, which is incorporated herein by reference. A representative commercial implementation can also be found in the FREEHAND™ System, sold by NeuroControl Corporation. (Cleveland, Ohio).
In an alternative arrangement (see FIG. 2 ), the leads 20 can be percutaneously installed and be coupled to an external interconnection block 24 taped to the skin. In this arrangement, the pulse transmitter 16 is directly coupled by a cable assembly 26 (see FIG. 3 , also) to the interconnection block 24 . In this arrangement, there is no need for a pulse transmitter 16 and receiver/stimulator 18 . A representative commercial example of this implementation (used to achieve neuromuscular stimulation to therapeutically treat shoulder subluxation and pain due to stroke) can be found in the StIM™ System, sold by NeuroControl Corporation (Cleveland, Ohio).
II. The Pulse Controller
The pulse controller 14 is desirably housed in a compact, lightweight, hand held housing 28 (see FIG. 3 ). The controller 14 desirably houses a microprocessor 30 . Desirably, the microprocessor 30 carries imbedded code, which expresses the pre-programmed rules or algorithms under which the desired electrical stimulation waveform is generated in response to input from the external control source 12 . The imbedded code can also include pre-programmed rules or algorithms that govern operation of a display and keypad on the controller 14 to create a user interface 32 .
A. The Desired Electrical Stimulation Waveform
The waveform 34 that embodies features of the invention is shown in FIG. 4 . A stimulus provided by this waveform 34 is delivered to a nerve N through the electrodes 22 located on or around the nerve N. The waveform 34 , when applied, places the nerve fiber membrane into a state in which it is unable to conduct action potentials.
The specific electrical stimulus waveform 34 that can be applied to cause a blocking of the transmission of action potentials along the nerve has two phases 36 and 38 (see FIG. 4 ).
The first phase 36 produces subthreshold depolarization of the nerve membrane through a low amplitude cathodic pulse. The first phase 36 can be a shaped cathodic pulse with a duration of 0.1 to 1000 millisecond and a variable amplitude between 0 and 1 milliamp. The shape of the pulse 36 can vary. It can, e.g., be a typical square pulse, or possess a ramped shape. The pulse, or the rising or falling edges of the pulse, can present various linear, exponential, hyperbolic, or quasi-trapezoidal shapes.
The second phase 38 immediately follows the first pulse 36 with an anodic current. The second anodic phase 38 has a higher amplitude and shorter duration than the first pulse 36 . The second pulse 38 can balance the charge of the first phase 36 ; that is, the total charge in the second phase 38 can be equal but opposite to the first phase 36 , with the second phase having a higher amplitude and shorter duration. However, the second pulse 38 need not balance the charge of the first pulse 36 . The ratio of the absolute value of the amplitudes of the second phase 38 compared to the first phase 36 can be, e.g., 1.0 to 5.0. Because of the short duration of the anodic phase 38 , the nerve membrane does not completely recover to the non-polarized state.
This biphasic pulse is repeated continuously to produce the blocking stimulus waveform. The pulse rate will vary depending on the duration of each phase, but will be in range of 0.5 Hz up to, 10 KHz. When this stimulus waveform 34 is delivered at the appropriate rate, typically about 5 kHz, the nerve membrane is rendered incapable of transmitting an action potential. This type of conduction block is immediately reversible by ceasing the application of the waveform.
Larger nerve fibers have a lower threshold for membrane depolarization, and are therefore blocked at low stimulus amplitudes. As a result, it is possible to block only the largest nerve fibers in a whole nerve, while allowing conduction in the smaller fibers. At higher stimulus amplitudes, all sizes of fibers can be blocked completely.
The physiological basis on which the waveform 34 is believed to work can be described .using the values of the sodium gating parameters, as shown in FIG. 5 . The unique ability of the nerve axon to transmit signals is due to the presence of voltage controlled ion channels. The function of the sodium ion channels are influenced by two gates. One gate responds quickly to voltage changes, and is frequently termed the “m” gate. The other gate responds more slowly to voltage changes, and is termed the “h” gate. When the nerve is in, the rest condition, the m gates are almost completely closed, while the h gates are partially opened. When an action potential propagates along the axon, the m gates open rapidly, resulting in a rapid depolarization of the nerve membrane. The h gates respond by slowly closing. The membrane begins to repolarize, and the m gates begin to close rapidly. At the end of action potential generation, the m gates have returned to their initial state and the nerve membrane is slightly more polarized than at rest. The h gates return more slowly to their resting values, producing a period of reduced excitability which is referred to as the refractory period. The same series of events can be initiated by an externally applied cathodic (depolarizing) stimulus pulse. This is the basis for electrical stimulation of nerves.
The waveform 34 of the invention makes use of the different relative responses of the two types of sodium ion channel gates. The first phase 36 of the waveform 34 is a subthreshold depolarizing pulse. The nerve membrane response is shown in FIG. 6 . The h gates begin to slowly close during the first phase, while the m gates respond by opening only slightly. As long as the initial phase is maintained below the activation threshold for the nerve, the m gates will exhibit only a small response. If the depolarizing pulse 36 is maintained for long periods of time, the h gates will eventually close to the point that the membrane is no longer able to transmit an action potential.
The second phase 38 of the waveform 34 is a hyperpolarizing pulse of shorter duration than the initial depolarizing pulse. The effect of this pulse 38 is to cause the m gates to close completely and the h gates begin to slowly open. However, since this phase 38 is shorter than the first phase 36 , the h gates do not return to their resting levels by the end of the phase 38 . A second pulse of the waveform 34 of the same shape is then delivered to the nerve. The depolarization of the first phase 36 results in further closing of the h gates, with slight opening of the m gates. Some opening of the h gates again occurs with the second hyperpolarizing phase 38 of the pulse, but recovery back to the initial value does not occur. With subsequent pulses, the h gate progressively nears complete closing, while the m gate varies slightly between fully closed and slightly open. Due to the dynamics of the h gate, it will not fully close, but will continue to oscillate with each pulse near the fully closed condition. With both the m gate and the h gate nearly closed, the nerve membrane is now incapable of conducting action potentials. The nerve is effectively blocked.
This block can be maintained indefinitely by continuously delivering these pulses to the nerve. The block is quickly reversible when the stimulation is stopped. The h and m gates will return to their resting values within a few milliseconds, and the nerve will again be able to transmit action potentials.
Larger nerve fibers will have a lower threshold for subthreshold depolarizing block. Therefore, when the blocking waveform is delivered to a whole nerve, only the largest nerve fibers will be blocked. This provides a means of selective block, allowing a block of motor activation without affecting sensory information, which travels along the smaller nerves.
In order to generate a block of smaller nerve fibers in a large nerve, the amplitude of the waveform can be increased. As the amplitude is increased, the first phase of the waveform may produce a stimulated action potential in the larger nerves. However, because of the nerve membrane dynamics, it is possible to gradually increase the stimulus amplitude over time with each successive pulse, until even the smallest nerve fibers are blocked. This, is shown in FIG. 7 . Very low amplitude pulses are used to put the membrane of the largest nerve fibers into an unexcitable state over the course of a few pulses. Once these largest fibers are at a steady state, they will not be activated even by very large cathodic pulses. At this point, the blocking stimulus amplitude can be increased so that it produces the closed h and m gate response in the smaller nerve fibers. The amplitude can be progressively increased until all nerve fibers are blocked. This progressive increase can occur rather quickly, probably within a few hundred milliseconds. This mechanism also serves to underscore the possibility of selective blocking of fibers of largest size using this waveform.
EXAMPLE 1
Neuroma Pain
A system 10 such as shown in FIG. 1 can be used to block neuroma pain association with an amputated arm of leg. In this arrangement, one or more electrodes 22 are secured on, in, or near the neuroma. The pulse controller 14 can comprise a handheld, battery powered stimulator having an on-board microprocessor. The microprocessor is programed by a clinician to generate a continuous waveform that embodies features of the invention, having the desired amplitude, duration, and shape to block nerve impulses, in the region of the neuroma. The pulse controller 14 can be coupled to the electrode, e.g., by percutaneous leads, with one channel dedicated to, each electrode used. A control signal source 12 could comprise an on-off button on the stimulator, to allow the individual to suspend or continue the continuous application of the waveform, to block the neuroma pain. No other special control functions would be required.
EXAMPLE 2
Muscle Spasms Due to Spinal Cord Injury, Cerebral Palsy, or Tourett's Syndrome
A system 10 like that shown in FIG. 1 can be used to block muscle spasms due to, e.g., a spinal cord injury, cerebral palsy, or tourett's syndrome. In this arrangement, one or more electrodes 22 are secured on, in, or near the nerve or nerves affecting the muscle spasms. As in Example 1, the pulse controller 14 can comprise a handheld, battery powered stimulator having an on-board microprocessor. The microprocessor is programed by a clinician to generate a continuous waveform that embodies features of the invention, having the desired amplitude, duration, and shape to block nerve impulses in the region of the muscle spasms. As in Example 1, the pulse controller 14 can be coupled to the electrode, e.g., by percutaneous leads, with one channel dedicated to each electrode used. A control signal source 12 could comprise an on-off button on the stimulator, to allow the individual to suspend or continue the continuous application of the waveform, to block the muscle spasms. Thus, for example, the individual could turn the stimulator off during sleep, or during a period where muscle function is otherwise desired. The selective stimulation-off feature also allows the individual to perform muscle functions necessary to maintain muscle tone. In this arrangement, no other special control functions would be required.
Alternatively, the control signal source 12 could comprise an electrode to sense electroneurogram (ENG) activity in the region where muscle spasms occur. The electrode could comprise the stimulation electrode itself, or a separate ENG sensing electrode. The electrode detects ENG activity of a predetermined level above normal activity (e.g., normal ENG activity X10), identifying a spasm episode. In this arrangement, the microprocessor is programed to commence generation of the desired waveform when the above normal ENG activity is sensed. The microprocessor is programmed to continue to generate the waveform for a prescribed period of time (e.g., 1 minute) to block the spasm, and then cease waveform generation until another spasm episode is detected. In this arrangement, the stimulator can also include a manual on-off button, to suspend operation of the stumulator in response to input from the sensing electrode.
EXAMPLE 3
Block Uncoordinated Finger Flexure Spasms Due to Multiple Sclerosis or Stroke
A system 10 like that shown in FIG. 1 can be used to block finger flexure spasms due to, e.g., a multiple sclerosis or stroke. In this arrangement, one or more epimysial and intramuscular electrodes 22 are appropriately implanted by a surgeon in the patient's arm. The implanted electrodes 22 are positioned by the surgeon by conventional surgical techniques to block conduction of impulses to finger flexure muscles. As in Example 1, the pulse controller 14 can comprise a handheld, battery powered stimulator having an on-board microprocessor. The microprocessor is programed by a clinician to generate a continuous waveform that embodies features of the invention, having the desired amplitude, duration, and shape to provide a low level block of nerve impulses to the finger flexure muscles. A control signal source 12 could comprise an on-off button on the stimulator, to allow the individual to select the continuous application of the waveform, e.g., while the individual is opening or closing their hand.
Alternatively, the control signal source 12 could comprise an electrode to sense electromyogram (EMG) activity in the finger flexor muscles. The electrode detects EMG activity during stimulated activation of the finger extensor muscles. If this activity exceeds a preset level (e.g. 30% maximum contraction level), the microprocessor is programmed to commence generation of the desired waveform to block some or all of the finger flexor muscle activity. The microprocessor can be programmed to deliver a block proportional to the level of EMG activity, or to deliver a block for a prescribed period of time, or to deliver a block as determined through a combination of parameters (e.g., EMG activity from multiple muscles in the arm).
In another alternative embodiment, the control signal source 12 can comprise comprises a mechanical joy stick-type control device, which senses movement of a body region, e.g., the shoulder. Movement of the body region in one prescribed way causes the microprocessor to commence generation of the desired waveform. Movement of the body region in another prescribed way causes the microprocessor to cease generation of the desired waveform.
In either alternative arrangements, the stimulator can also include a manual on-off button, to suspend operation of the stumulator in response to the external inputs.
Various features of the invention are set forth in the following claims. | Systems and methods for blocking nerve impulses use an implanted electrode located on or around a nerve. A specific waveform is used that causes the nerve membrane to become incapable of transmitting an action potential. The membrane is only affected underneath the electrode, and the effect is immediately and completely reversible. The waveform has a low amplitude and can be charge balanced, with a high likelihood of being safe to the nerve for chronic conditions. It is possible to selectively block larger (motor) nerve fibers within a mixed nerve, while allowing sensory information to travel through unaffected nerve fibers. | 0 |
FIELD OF THE INVENTION
The present invention relates to parity generation and checking generally and, more particularly, to a parity generation and checking circuit and method positioned in a read data path of a memory buffer.
BACKGROUND OF THE INVENTION
Parity generation provides a simple means for detecting errors in both data recording and data transmission. A data quantity may be allocated a parity bit having a value which may be computed from the various bits of the data. A parity bit may be generated from the various bits of the data being read. The data can have even or odd parity and the parity bit will be responsible for making the data and parity bit be even or odd based on user input. The parity bit designates whether or not a transmitted character, or data packet, has arrived correctly. During parity checking, if the device is configured to always have even parity, the parity checking feature will indicate a parity error if odd parity is received. On existing first-in first-out (FIFO) buffers, the parity generation and checking circuitry may be located in the write data path of the integrated circuit or chip. As memory devices generally, and FIFO devices particularly, provide additional access speeds and more efficient real estate utilization, the parity generation and checking circuitry in the write data path can slow down the performance of the device.
SUMMARY OF THE INVENTION
The present invention provides a circuit and method for generation of a parity bit that may be positioned in the read data path of a memory device or buffer. The present invention also provides for checking the data bits for a specified parity (e.g., odd or even) and indicating an error if appropriate. The parity generation and checking circuit can detect errors in both the data input to the buffer or memory device as well as errors created in the storage of the data by the buffer or memory device. By placing the parity generation and checking circuity in the read path, a look-ahead architecture can increase the overall performance of the buffer or memory device.
The objects, features and advantages of the present invention include providing a parity generation and checking circuit positioned in the read data path of a memory device or buffer. The circuit may reduce die size and may reduce data set-up and hold time. The circuit also provides the ability to check the integrity of the memory core of the buffer.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which:
FIG. 1 is a block diagram of the parity generation and checking circuit of a preferred embodiment of the present invention;
FIG. 2 is a more detailed block diagram of the preferred embodiment of the present invention;
FIG. 3 is a circuit diagram of the SelectGen block shown in FIG. 2;
FIG. 4 is a circuit diagram of the ParityGen block shown in FIG. 2;
FIG. 5 is a circuit diagram of the output register block shown in FIG. 2;
FIG. 6 is a circuit diagram of the Parity Register block shown in FIG. 2;
FIG. 7 is a circuit diagram of a CMOS pass gate; and
FIG. 8 is a circuit diagram of an enabled inverter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a block diagram of a circuit 10 is shown in accordance with a preferred embodiment of the present invention. The circuit 10 comprises an input section 12, a memory array 14, a sense amplifier block 16, a parity generation/check block 18 and an output section 20. The input section 12 receives data from an external device (not shown) and presents the data to the memory array 14. The memory 14 stores the data and then presents the data to the sense amplifier block 16. The sense amplifier block 16, which acts as output device or means for reading data from the memory array can also be implemented as a latch or any other device that provides the equivalent function(s) of sensing and/or amplifying an electrical potential. The parity generation/check block 18 receives data from the sense amplifier block 16 and presents data to the output section 20.
Since the parity generation/check block 18, in one example, may be placed after the memory array 14, errors can be detected which may be created from both the input data as well as from the memory array 14. Both the validity of the incoming data as well as the validity of the data stored in the memory array 14 may be determined by the parity generation/check block 18. The parity generation/check block 18 does not distinguish whether the error came from the incoming data or the memory array 14.
The memory array 14 can be a first-in first-out (FIFO) buffer, a static random access memory (SRAM), a content addressable memory (CAM), a CACHE memory, a dynamic random access memory (DRAM), a TAG memory, a dual port memory or any other type of memory array.
The data input section 12 generally comprises a set of input pads 22 and a set of input buffers 24. The input buffers 24 provide an additional layer of buffering prior to the memory array 14. The output section 20 generally comprises a set of output buffers 26 and a set of output pads 28. The output buffers 26 provide an additional layer of buffering between the memory array 14 and the external device.
The data input section 12 presents data received from an external device to the memory array 14 through a bus 29. The bus 29 may be a multi-bit bus which presents data to the memory array 14. In one example, the bus 29 may be a 9-bit bus. However, other width busses may be used to implement the bus 29. The memory array 14 presents data to sense amplifier block 16 through a bus 30. The sense amplifier 16 presents data through a bus 32 directly to the data output section 20. The sense amplifier 16 presents data to the parity generation/check section 18 through a bus 34. The bus 34, in one example, may have the same or different width as bus 32 (see for example, U.S. Ser. No. 08/624,182, filed Mar. 29, 1996, Attorney Docket No. 16820.P133) The bus 34 may be 1-bit smaller than bus 32 since there may be either a generation of a parity bit or the checking of parity from the Gen/check block 18. There may be some multiplexing between an operation producing 9-bits of data and an operation producing 8-bits of data and the parity check bit to the output section 20.
Since the parity generation/check block 18 may be located after the memory array 14, any errors received from the memory array 14 may be detected by the parity generation/check block 18. If the data received by the data input section 12 creates an error or the data received from the memory array 14 creates an error, the parity generation/check block 18 may detect the error. This provides the advantage of having a single parity generation/check block 18 which may detect errors from multiple sources. Furthermore, the chip real estate necessary to implement the parity generation/check block 18 after the memory array 14 may be available on the currently produced dies in an unused portion of the silicon.
Referring to FIG. 2, a more detailed block diagram of the circuit 10 is shown. The data output section 20 generally comprises a output register 38 and a parity register 40. The output register 38 has an input 39 which (if eight bits wide) may receive the first eight bits (i.e., <0:7>) of the data packet received from the bus 33. The output register 38 presents a signal at the output 41 which represents the signal received at the input 39.
The parity generation/check block 18 comprises a SelectGen block 42 and a ParityGen block 44. The SelectGen block 42 has an input 46 which receives the ninth bit (i.e., <8>) of the data received on the multi-bit bus 34. The SelectGen block 42 also has an input 48 which receives two bits (i.e., PGM <6:7>) of a three bit configuration signal PGM. The SelectGen block 42 presents a signal EVENSEL through the output 49 to the parity register 40. The ParityGen block 44 has an input 50 which also receives the first eight bits (i.e., <0:7>) of the data received on the bus 34, similar to the data received at the input 39 of the output register. The ParityGen block 44 presents a signal ODD at an output 54 and a signal EVEN at an output 52.
The parity register 40 has an input 56 which may receive the ninth bit (i.e., <8>) of data received on the bus 34, an input 58 which may receive the signal EVENSEL from the SelectGen block 42, an input 60 which may receive the signal EVEN from the ParityGen block 44, an input 62 which may receive the signal ODD from the ParityGen block 44 and an input 64 which may receive a third bit (i.e., PGM <8>) of the three bit configuration signal PGM. The parity register 40 has an output 66 which may present a single-bit output signal which may be either a parity generation bit, a parity error bit or the ninth bit of data. The output 66 and the output 41 are combined to form an output Q which represents the eight data bits <0:7> and the one bit from the parity register <8> to form a nine bit signal Q <0:8>.
The PGM input 48 and the PGM input 64 work in combination to form the three-bit configuration signal PGM which may be used to generate various parity options such as parity disabled, generate even parity, generate odd parity, check for even parity and check for odd parity. The PGM inputs 48 and 64 configure the circuit according to the following TABLE 1:
TABLE 1______________________________________Programmable parity OptionsPGM8 PGM7 PGM6 Condition______________________________________0 X X Parity disabled.1 0 0 Generate even parity at output 66.1 0 1 Generate odd parity at output 66.1 1 0 Check for even parity. Indicate error at output 66 if odd parity found.1 1 1 Check for odd parity. Indicate error at output 66 if even parity found.______________________________________
The configuration signal PGM may be programmed using various methods including, for example, programming during a master reset cycle, programming a register by a user providing a specific program sequence (e.g., a write program register instruction or an execution) or providing a write program register cycle which the user can use to dynamically change the program register. Metal options may be implemented on the die so that the fabrication process allows for specific dies that are either configured to be parity disabled, generate even or odd parity or check for even or odd parity. The configuration signal PGM can be generated by allowing the user to dynamically specify which mode to operate in. The configuration signal PGM may have dedicated pins on the output of the package, (e.g., PGM 6, 7 and 8) that are externally presented allowing a static signal to be presented at all times as shown in TABLE 1. A high voltage detection could also be implemented to generate the configuration signal PGM. Other means to provide the configuration signal PGM may be used according to the design criteria of a particular application.
In a mode when the parity may be disabled, the memory array 14 may store 9-bits of data received from the data input section 12 internally and may output 9-bits to the data output section 20.
When the configuration signal PGM selects even parity, the ninth bit is preferably a 1 if there are an odd number of 1's in <0:7> or a 0 if there are an even number of 1's in <0:7>. When the configuration signal PGM signal selects an ODD parity gen, the ninth bit is preferably a 1 if there are an even number of 1's in <0:7> or a 0 if there are an odd number of 1's in <0:7>.
The circuit 10 may be programmed for parity checking which may allow the circuit to compare the parity of the bits <0:8> with even or odd parity as selected by parity configuration signal PGM. When these words are later read, the output 66 may reflect the result of the parity check. If a parity error occurs in the bits <0:8>, the parity error bit <8> may be set LOW internally. When this word is read, the ninth bit <8> will preferably indicate the results of the parity check.
Referring to FIG. 3, the SelectGen block 42 is shown in greater detail. The SelectGen block 42 is shown having an input 46, an output 49, an input 48a and an input 48b which may represent the two bits (i.e., <6:7>) of the three-bit parity configuration signal PGM received at the input 48. The input 48a receives a signal PGM6 while the input 48b receives a signal PGM7. The signal PGM6 and the signal PGM7 correspond to the column headings illustrated in TABLE 1. The SelectGen block 42 comprises an array of inverters and transistors configured to produce the signal EVENSEL presented at the output 49. The input 46 represents the bit <8> received from the bus 34.
Referring to FIG. 4, the ParityGen block 44 is shown in greater detail. The ParityGen block 44 generally comprises an exclusive NOR gate (XNOR) 70, an XNOR gate 72, an XNOR gate 74 and an XNOR gate 76 which each may receive two bits of the 8-bit signal received at the input 50. The output of the XNOR gate 70 is generally presented to both an input of an inverter 78 as well as the drain of a transistor 80. The output of the inverter 78 is generally presented to the gate of the transistor 80 as well as to a first input of an XNOR gate 82. Similarly, the output of the XNOR gate 72 is generally presented to both an inverter 88 as well as to the drain of a transistor 90. The output of the inverter 88 is generally presented to the gate of the transistor 90 as well as to a second input of the XNOR gate 82. The sources of the transistors 80 and 90 are generally connected to an input supply voltage (not shown). The output of the XNOR gate 82 is generally presented to both an inverter 92 as well as to the drain of a transistor 94. The output of the inverter 92 is generally connected to both the gate of the transistor 94 as well as to a first input of an XNOR gate 96.
The output of the XNOR gate 74 is generally presented to both an inverter 98 as well as to the drain of a transistor 100. The output of the inverter 98 is generally presented to both the gate of the transistor 100 as well as to a first input of an XNOR gate 102. Similarly, the XNOR gate 76 generally presents an output to both an inverter 104 as well as to the drain of a transistor 106. The output of the inverter 104 is generally presented to both the gate of the transistor 106 as well as to a second input of the XNOR gate 102. The sources of the transistors 100 and 106 are generally connected to an input supply voltage (not shown). The output of the XNOR gate 102 is generally presented to both an inverter 108 as well as to the drain of a transistor 110. The output of the inverter 108 is generally presented to the gate of the transistor 110 as well as to a second input of the XNOR gate 96.
The output of the XNOR gate 96 is generally presented to an inverter 112, to an inverter 114 and the drain of a transistor 116. The output of the inverter 114 is generally presented to an inverter 118 as well as to the gate of the transistor 116. The sources of the transistors 94, 110 and 116 are generally connected to an input supply voltage (not shown). The output of the inverter 112 generally presents the signal ODD at the output 52. The output of the inverter 118 generally presents the signal EVEN at the output 54. The detailed description shown in FIG. 4 illustrates one example of implementation of the parity generation block 44. Other implementations performing a similar function may be substituted without departing from the spirit of the invention.
Referring to FIG. 5, a circuit diagram of the output register block 38 is shown. The output register block 38 generally comprises an input 120, an input 122, an input 39 and an input 126. The output register block 38 generally presents an output 41. The output register block 38 generally comprises an inverter 132, an inverter 134, an inverter 136, an inverter 138, an inverter 140, an inverter 142, an inverter 144, a CMOS pass gate 146, an enabled inverter 148 and a transistor 150. The input 120 generally receives a signal READ representing a signal derived from the read clock (not shown). The signal READ may follow the external read clock. The input 122 generally receives a signal RDELB representing a delayed complement of the signal READ. The input 126 generally receives a signal RSTB which provides a reset function (i.e., drives each of the outputs to zero).
The CMOS pass gate 146 has a PMOS gate which generally receives the input 122 through the inverter 132 as well as a NMOS gate which generally receives the input 122. The input of the CMOS pass gate 146 generally receives the input 39. The output of the CMOS pass gate 146 is generally presented to the inverter 136 as well as to the output of inverter 134. The output of the inverter 136 is generally presented to the inverter 140 as well as to the inverter 134. The output of the inverter 134 is generally presented to the input of the inverter 136 as well as to the output of CMOS pass gate 146. The output of the inverter 140 is generally presented to a p-data input of the enabled inverter 148 as well as to a n-data input of the enabled inverter 148. The p-enabled input of the enabled inverter 148 may receive a signal from the input 120 through the inverter 138. The n-enabled input of the enabled inverter 148 may receive a signal from the input 120. The output of the enabled inverter 148 is generally presented to the inverter 144 and the drain of the transistor 150 as well as to the output of inverter 142. The output of the inverter 144 is generally presented to the output 41 as well as to the inverter 142. The output of the inverter 142 is generally connected to the input of the inverter 144 and the drain of the transistor 150 and to the output of enabled inverter 148. The source of the transistor 150 is generally connected to an input supply voltage (not shown). The gate of the transistor 150 is generally connected to the input 126. A block 152 represents the output section of the output register block 38.
Referring to FIG. 6, the parity register 40 is shown in greater detail. The parity register 40 generally comprises an input 58, an input 60, an input 64, an input 62, an input 162, an input 164, an input 56, an input 168 and an output 66. The parity register 40 generally comprises an output section 152, an inverter 176, a NAND gate 178, a NAND gate 180, an inverter 182, a CMOS pass gate 184, an inverter 186, a CMOS pass gate 188, an inverter 190, a NAND gate 192, an inverter 194 and a CMOS pass gate 196. The output section 152 comprises similar components as the output section 152 of the output register 38. The input 58 generally presents a signal to a first input of the NAND gate 178 as well as to the inverter 176. The inverter 176 presents an output to a first input of the NAND gate 180. A second input of the NAND gate 178 is generally connected to the second input of the NAND gate 180, a first input of the NAND gate 192 and the input 164. The third input of the NAND gate 178 is generally connected to the third input of the NAND gate 180 and the input 64. The input 64 is generally connected to the second input of the NAND gate 192 through the inverter 190. The output of the NAND gate 178 is generally connected to the PMOS gate of the CMOS pass gate 184 as well as to the inverter 182. The output of the inverter 182 is generally connected to the NMOS gate of the CMOS pass gate 184. The input of the CMOS pass gate 184 is generally connected to the input 60. The output of the CMOS pass gate 184 is generally connected to the output of the CMOS pass gate 188, the output of the CMOS pass gate 196, and the inverter 136'. Similarly, the output of the NAND gate 180 is generally connected to the PMOS gate of the CMOS pass gate 188 as well as to the inverter 186. The output of the inverter 186 is generally connected to the NMOS gate of the CMOS pass gate 188. The input of the CMOS pass gate 188 is generally connected to the input 62. The output of the NAND gate 192 is generally connected to the PMOS gate of the CMOS pass gate 196 as well as to the inverter 194. The output of the inverter 194 is generally connected to the NMOS gate of the CMOS pass gate 196. The input of the CMOS pass gate 196 is generally connected to the input 56. The input 162 is generally connected to both the inverter 138' as well as the n-enabled input of the enabled inverter 148'. The input 168 is generally presented to the gate of the transistor 150'.
The CMOS pass gates 184, 188 and 196 work in combination with the inverters 176, 182, 186, 190 and 194 as well as the NAND gates 178, 180 and 192 to form a multiplexer. The outputs of the multiplexer are fed to the output section 152.
Referring to FIG. 7, a CMOS pass gate is shown in greater detail. The PMOS gate input may be represented by the signal PIN while the NMOS gate input may be represented by the signal NIN. The input may be represented by the signal IN while the output may be represented by the signal OUT.
Referring to FIG. 8, an enabled inverter is shown in greater detail. The P-data input may be represented by the signal P0, the p-enabled input may be represented by the signal P1, the n-enabled input may be represented by the signal N1 and the n-data input may be represented by the signal N0.
The schematic diagrams in FIGS. 4-8 are shown as being implemented using PMOS and NMOS transistors. Other topologies may be substituted to meet the design criteria of a particular application.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | The present invention provides a circuit and method for generating a parity bit and checking the parity of data words positioned in the read data path of a memory device or buffer. The parity check mode can detect errors. The parity generation mode generates EVEN or ODD parity as an additional bit. Other devices in the system may generally be configured to accept either EVEN or ODD parity. The parity generation and checking circuit can detect errors in both the data input to the buffer as well as errors created in the storage of the data by the buffer. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to electrically heated catalytic converter modules for automotive exhaust gas treatment applications. More particularly, the invention relates to an improved design for an assembly for such modules specially adapted for use with metallic honeycomb heaters for electrically heated catalytic converter modules.
The use of axially assembled enclosures containing ceramic honeycomb-supported catalysts for the treatment of automotive exhaust gases is known. U.S. Pat. No. 4,207,661 to Mase et al., for example, describes such an assembly comprising forward and rear case halves into which a ceramic catalytic converter substrate can be inserted. Included in the assembly are front and rear supporting members composed of a resilient material for supporting the catalytic converter substrate within the enclosure while shielding it from mechanical shocks.
Axial assembly in the manner of the above patent is advantageous in that the number of components required to securely encase the catalytic substrate within the shielding metal container is relatively small, and in that axial compression of the resilient supports for the ceramic honeycomb within the enclosure to improve the mechanical shock resistance of the assembly is more easily effected. However, one disadvantage of many of these enclosures is that the compression levels attainable are not variable, but are instead constrained by the relative dimensions of the can and honeycomb. And, as in U.S. Pat. No. 5,250,269, some designs do not utilize axial compression at all.
More complex axial constructions, such as that described in U.S. Pat. No. 4,347,219 to Noritake et al., can overcome some of these difficulties. However, the assemblies of the latter patent require a relatively large number of parts, and thus a large number of associated assembly and welding steps. Further, many of these assemblies are designed to contain relatively long honeycomb bodies and, more importantly, make no provision for gas-tight electrode feed-throughs since they are designed for catalyst substrates rather than flow-through heaters.
It has so far not been feasible to directly adapt canning assemblies for ceramic catalytic converters to the mounting of metal honeycomb heaters. Among the problems encountered in this regard is the fact that metal honeycombs for the electrical heating of exhaust gases or other fluids require electrical contacts for electrically energizing the honeycombs. These contacts typically comprise relatively heavy electrodes which pass through the walls of the metal containers used to enclose and protect the honeycombs.
Electrode pass-through structures have presented a design challenge in that they must be both gas-tight and electrically insulating, to prevent exhaust leakage as well as grounding of the electrodes to the containers.
Enclosures for electrically heated metal honeycombs for automobile exhaust use must also provide physical protection adequate to enable the heaters to meet government mandated standards for maximum allowed levels of non-methane hydrocarbons, CO, and nitrogen oxides for up to 100,000 miles of automobile use. This can involve up to 50,000 engine starting cycles and requires sustained heater integrity under severe thermal cycling, extreme temperatures, and high temperature vibration.
The problem of physical protection is aggravated by the fact that metal honeycomb designs useful for electrical heaters are somewhat lower in crushing strength and durability than their ceramic counterparts, especially at elevated engine exhaust temperatures. This places a premium on the effectiveness of the enclosure design for insulating the metal honeycomb structure from mechanical shock damage.
Finally, a number of exhaust system designs incorporating honeycomb exhaust heaters require the close mounting of a metallic or ceramic honeycomb-supported auto exhaust catalyst, called a light-off catalyst, against the heater. This is required so that electrically generated heat energy can be efficiently transferred from the metal honeycomb heater to the light-off catalyst, in order that rapid heating of the catalyst to operating or so-called light-off temperatures can be achieved.
Previous efforts to meet the various requirements for supporting heating elements in automotive exhaust systems have involved a clam-shell assembly packaging approach, wherein top and bottom half-shell enclosure sections having electrode pass-through holes or recesses have been radially compressed together over the honeycomb heater and associated insulation material. These enclosure portions are then welded together. Such enclosures have proven to be complex to assemble, and the parts are costly to fabricate. In addition, even small variations in the shape or size of the parts can result in large variations in the preloading forces under which the honeycomb heater is protected from vibration damage in the enclosure.
SUMMARY OF THE INVENTION
The present invention provides an improved honeycomb heater enclosure and enclosed heater particularly well adapted for sustained effective operation in the treatment of motor vehicle engine exhaust gases. The improved enclosure uses strong and easily formed tubular metal elements offering high inherent strength. Thus these elements can be welded together to provide a durable sealed enclosure for a metal honeycomb heating element.
The resulting heater enclosure has a design which permits convenient mating with a light-off catalyst module to provide a rugged electrically heated catalyst module as a single unit. The overlapping joints of the heater enclosure and heated catalyst module can easily be welded or otherwise sealed to insure a strong, gas-tight assembly exhibiting little or no exhaust gas leakage.
A particularly important aspect of the invention involves the use of an accurately preloaded resilient mounting material between the mounted honeycomb heater and the heater enclosure to minimize the likelihood of vibration damage to the heater in use. The axial assembly method hereinafter described permits a predetermined loading force to be applied, during the assembly procedure, to the resilient mounting material and heater on the strong axis of the heater, i.e., the heater axis parallel to the direction of the channels and channel walls of the honeycomb. This loading force is permanently maintained in the sealed assembly, with the result that optimum mechanical shock absorption by the mounting material and enclosure is insured.
In a first aspect, then, the present invention provides an improved method for mounting a channeled metal honeycomb heater in a protective enclosure. That method comprises positioning the honeycomb between first and second open-ended tubular enclosure members, each enclosure member having a bore sized to accept the honeycomb and a stop or support within the bore sized to support both the honeycomb and a resilient mounting material within the completed enclosure. Typically the stop is a permanent feature formed in or affixed to the bore to provide peripheral or edge support for the honeycomb.
The resilient mounting material is provided between the honeycomb and each of the stops, and the first and second tubular enclosure members are urged together to cause the stops to apply a predetermined preloading force to the resilient mounting material and honeycomb. Then, while maintaining the predetermined preloading force, the first and second tubular enclosure members are permanently joined by welding or the like into a unitary protective enclosure wherein the honeycomb is suspended within the enclosure by the preloaded mounting material.
The sealed enclosure or assembly of the invention is particularly well adapted for resiliently supporting a metal honeycomb heater or other device of open-ended cellular structure in a system for treating a fluid such as exhaust gas from an internal combustion engine. Describing the enclosure itself in more detail, the principal components consist of a pair of tubular metal elements within which the honeycomb is axially enclosed. The tubular elements include a first tubular metal element having a bore defining a fluid input end and a first honeycomb mounting end, the bore including within the first honeycomb mounting end a first interior support for supporting the honeycomb within the bore. This support, which can be a ledge, step, or other protrusion into the bore from the wall of the tubular element, prevents movement of a honeycomb supported thereby further into the bore toward the fluid input end of the tube.
In preferred embodiments at least a portion of the first honeycomb mounting end extends beyond or past the support to form a first honeycomb retaining lip. This lip acts to limit lateral movement of a honeycomb positioned on the first support.
The assembly further includes a second tubular metal element having a bore defining a second honeycomb mounting end and a fluid output end, that bore including within the second honeycomb mounting end a second interior support for supporting a honeycomb within the bore. Again, at least a portion of the second mounting end extends beyond the support to form a second honeycomb retaining lip for restricting lateral movement of a honeycomb supported thereon.
The honeycomb comprising the electrical heating element of the assembly is a metal honeycomb of cellular structure which is disposed between the first and second supports in the bores of the tubular elements. When so disposed, the honeycomb is aligned to permit the passage through its cellular passages of a fluid, such as an exhaust gas, which is to be treated. Treatment by the heater typically involves only heating, although heating and catalytic conversion could be simultaneously accomplished by depositing a catalyst within the cells of the metal honeycomb.
For protection of the metal honeycomb against damage from mechanical shock and vibration, a resilient mounting material is positioned between the metal honeycomb and each of the supports. Most preferably, at least some resilient material is also disposed between the honeycomb and the retaining lips adjacent the supports.
In constructing the assembly of the invention, the two tubular metal elements are brought together in telescoping fashion to form a lap joint wherein the first and second honeycomb retaining lips overlap. Thus the joint area formed by the juxtapositioning of the two elements is of double wall thickness, comprising an overlapping lip and an underlying lip. In this position, the overlying lip is situated for easy fastening to the metal forming the underlying lip, either to the lip itself or to adjoining portions of the tubular metal element forming the underlying lip.
A key characteristic of the final assembly is that the underlying lip is sufficiently short to be clear of contact with the support extending from the tubular element forming the overlapping lip, at least when a honeycomb of selected axial length is positioned between the supports. Providing a clearance between the underlying lip and the support extending from the base of the overlying lip permits the first and second supports to be brought closely enough together that they can apply an equal and opposite mounting pressure or preloading force to the resilient mounting material and metal honeycomb disposed therebetween. The level of mounting force is predetermined or preselected to provide a level of honeycomb clamping force sufficient for the intended use.
Finally, the overlapping lip of the assembly is fastened by welding or other attachment means to the metal element forming the underlying lip. This fastening maintains the relative positions of the first and second supports at that spacing initially selected to achieve the desired preloading force, thereby permanently mounting the honeycomb and resilient mounting within the enclosure under the desired supporting load.
An enclosed metal honeycomb heating element produced as above described exhibits excellent durability in the harsh environment of an internal combustion engine exhaust system. Thus sustained heating efficiency even after repeated exposure to 950° C. exhaust gas temperatures and 30 G acceleration forces can be expected. And it offers a construction readily adapted for close coupling with a companion light-off catalyst to provide effective control of start-up engine emissions during initial (cold-start) engine operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be further understood by reference to the appended drawings wherein:
FIG. 1 is a schematic side cross-sectional view of an electrical honeycomb heater supported within an axially assembled enclosure in accordance with the invention;
FIG. 2 is a schematic top cross-sectional view of the enclosure of FIG. 1.
FIG. 3 is a schematic side elevational view of an assembled electrical honeycomb heater enclosure according to the invention;
DETAILED DESCRIPTION
Electrical heaters useful in the practice of the invention may be of any the types which have been developed for the electrical heating of exhaust gas effluents. The preferred heaters are extruded metal honeycombs, examples of which are disclosed in U.S. Pat. Nos. 5,254,840 and 5,194,719. Alternatively, heaters comprised of sheet metal and fabricated by wrapping metal foil into channeled honeycomb configurations can be used.
In the case of extruded metal honeycomb heating elements, such as best illustrated in FIGS. 1 and 2 of the drawing, the particularly preferred configuration is a round disk 10 of extruded metal honeycomb material having the channels or cells running axially through the disk. Slots 12 are formed through the disk cross-section by removing some of the cell walls, in order to create a serpentine conductive path which increases the electrical resistance of the disk for more efficient electrical heating at typical motor vehicle battery or alternator voltages.
Powering electrodes in the form of metal studs 14 are welded to the side of the honeycomb at opposite ends of the serpentine path. These studs serve as the electrodes for connection to an electrical power source. In the embodiment shown, each stud is provided with an insulating ceramic coating 14a to electrically isolate it from bushings 15 attached to surrounding metal enclosure elements to be hereinafter described.
The slots 12 in honeycomb 10 are preferably kept separated by insulating pins 16 formed of a refractory electrically insulating material such as an alumina ceramic, the pins being retained in holes drilled into each slot from the perimeter of the honeycomb.
To electrically insulate and mechanically isolate the metal honeycomb from its surrounding enclosure, a layer of resilient insulating mounting material 18 is provided around the honeycomb. This layer, which may be formed of any electrically insulating, refractory, woven or non-woven resilient material, must be sufficiently refractory to resist deterioration at maximum exhaust system temperatures and sufficiently durable to withstand prolonged vibration and moderate to severe mechanical shocks.
The mounting material must also be sufficiently resilient to transmit a useful level of preloading force to the honeycomb heater, and to retain that force at high use temperatures. Preferred materials for the resilient mounting material are woven mat materials formed of refractory fibers, although non-woven mats or even resilient insulating foam materials, if sufficiently refractory, could alternatively be employed. With current resilient materials and honeycomb designs, preloading forces in the range of about 25-500 lbs. force, generating pressures in the 25-500 psi range on the edge portions of the honeycombs supported by the stops, are expected to provide useful levels of shock protection for the honeycombs.
In the particularly preferred embodiment of FIGS. 1-3, the enclosure is formed by tubular elements 20 and 22 which are joined together and welded at junction 23. Element 20 forms the gas inlet for the assembly, with exhaust gas entering the assembly in the direction of arrow 30 in FIG. 2, and exiting the assembly in the direction of arrow 32 after passage through honeycomb 10.
Within the honeycomb mounting end of element 20, which is the end at junction 23, the wall of element 20 forms a step or ledge 20a protruding into the bore of the element. That step provides support for honeycomb 10 and its associated mat 18. The wall portion of element 20 extending in the direction of gas flow from step 20a provides a retaining lip to restrict lateral movement of honeycomb 10 and mat 18.
Tubular element 22 forms the gas outlet end of the assembly. The honeycomb mounting end of element 22, which is that end telescoping into and joining with the mounting end of element 20, also includes interior support for the honeycomb. That support comprises ledge or ring 22a which extends from the sidewall of element 22 into the bore thereof to constrain movement of and provide support for honeycomb 10 and associated mat 18. As evident from these Figures, ledge 22a cooperates with ledge 20a of element 20 to laterally and axially hold honeycomb 10 and mat 18 firmly within the assembly of tubular elements 20 and 22.
Finally, each of elements 20 and 22 are preferably provided in the retaining lip portion with cutouts such as cutout 21 in element 20, best seen in FIG. 3. These cutouts or slots provide clearance between the elements 20 and 22 and the electrode subassemblies 14, 14a and 15 connected to the honeycomb heater 10, so that the elements 20 and 22 can be brought together to compress the resilient mounting insulation without blockage by the electrodes.
An example of the construction of an assembly such as shown in the drawings is as follows.
EXAMPLE
An extruded metal honeycomb disc for a heater element, being about 9.3 cm in diameter and 1 cm in thickness and incorporating edge slotting with insulating pins as shown in FIG. 2 of the drawing, is first provided. To opposing outer edges of the honeycomb disc are attached two opposing electrodes for electrical contact with the disc. Each electrode consists of a stainless steel stud about 8 mm in diameter which is welded to the disc for electrical contact. Each stud supports an insulating ceramic coating on its side surfaces.
A wrap of woven insulation in the form of a fibrous mat is draped around the perimeter of the honeycomb. This mat, formed of Nextel® ceramic fiber mat material commercially available from the 3M Company, Minneapolis, Minn., has insulating and electrical characteristics suitable for thermally and electrically isolating the heater from surrounding metal. The wrap includes opposing holes through which the electrode studs can protrude.
The wrapped heater element thus provided is inserted with its surrounding wrap into the end opening of a half-enclosure having the configuration of a short, open-ended cylindrical steel tube having a configuration such as shown for tubular element 22 in FIGS. 1 and 3 of the drawing. The tube, referred to as an outlet bell, incorporates a mild end flare from an terminating (gas outlet) bore diameter to a slightly larger inlet bore diameter sufficient to accept the wrapped element. When the wrapped element is inserted into the larger diameter tube bore, the tube sidewall forms a retaining lip to prevent lateral movement of the wrapped heater within the bore.
The flared end of the tube includes a pair of opposing sidewall cutouts to provide clearance between the tube wall and the protruding heater electrodes. Also provided is a steel ring positioned within the bore and welded to the inner wall of the flared end of the tube to form a protruding ledge. This ring provides a step for supporting the wrapped heater element within the tube. It is located sufficiently close to the mouth of the tube to insure that the wrapped heater when seated on the step will not be fully recessed within the tube bore but will instead protrude at least partially from the tube end.
A second half-enclosure consisting of a second short, open-ended cylindrical steel tube is next provided, having a configuration like that of tubular element 20 in FIGS. 1 and 3 of the drawing. This tube, referred to as an inlet bell, flares from an entrance or gas inlet bore to a larger bore intended to enclose the heater. The diameter of the larger bore is sufficient both to enclose the wrapped heater element and to telescope over the flared end of the first tube surrounding the element.
The flare from the smaller to the larger diameter in the second tube is sufficiently abrupt to form a circular step in the tube wall. This circular step is sized to cover approximately the same portions of the outer diameter of the wrapped heater as the ring in the bore of the first tube, so that equal opposing pressure can be exerted on both sides of the heater element as the tubes are brought together. The tube sidewall forming the larger diameter bore also includes a pair of opposing sidewall cutouts to provide clearance for the protruding heater electrodes.
Support for the wrapped heater by this second tube can alternatively be provided or supplemented by a ring affixed to the tube wall in the manner of the support ring in the first tube. Such a ring can be useful in cases where the step provided by the flare in the tube wall is not wide enough to provide the desired level of heater support, or where the honeycomb heater body is sufficiently thin that the desired preloading force on the insulation cannot be achieved due to interference between the a heater electrode and a sidewall cutout, or between a stop and a honeycomb retaining lip.
To complete the assembly of the heater enclosure the two tubes are brought together until the end portion of the sidewall of the inlet bell telescopes over and at least partially overlaps the end portion of the sidewall of the outlet bell, and until the circular step in the bore of the inlet bell comes into contact with the wrapped heater element protruding from the bore of the outlet bell. The sidewall cutouts of both tubes are aligned with the electrodes during this step to assure electrode clearance from the sidewalls of the tubes.
To obtain adequate preloading of the insulation encasing the wrapped heater element, the inlet and outlet bells are urged together under a force of approximately 200 pounds. When compressed in this way fibrous insulation of this type acts as a mechanical spring, having a both a measurable spring rate and some level of internal damping.
In the present case, at a preloading level of 200 pounds, the instantaneous spring rate of the insulation is 9,200 pounds per inch. This rate is adequate to effectively suspend the heater element within the metal enclosure to provide effective protection from vibration damage. Of course, the preloading force may be varied as needed to optimize the protection afforded the heater by the particular insulation selected, in light of the conditions of use for the heater which are anticipated.
While maintaining this preloading force level on the enclosed heater element the enclosure halves are spot welded together to permanently set the preloading level on the heater element. FIG. 3 of the drawing shows the assembly at this stage of the process, wherein the tubes have been joined together to contain the heater element, for example by spot welds at junction 23, but not sealed.
After the elements have been preliminarily joined, the joint between the overlapping sidewalls of the two tubes is seam welded to form a strong lap joint between the tubes. Finally, steel bushings placed over each of the electrodes and against the overlapping sidewalls are welded to the walls. These welding steps are carried out to achieve substantially gas-tight closure of the lap joint and electrode cutouts.
Inasmuch as the welding process affects the temperature and thus the dimensions of the tubes the preloading level can fluctuate during and at the end of the welding process. However, the effects of these fluctuations are predictable and can readily be compensated for in selecting the preloading levels to be initially applied.
Durability testing of the heater contained within the enclosure as above described is carried out under environmental conditions designed to approximate those encountered in an automotive exhaust environment. The test used, denominated a hot vibration test, involves hot vibration of the welded unit at 950° C. under 100 hertz, 30 G acceleration. These are conditions which cause repeated flexing of the heater element at temperatures where the element is most susceptible to damage from fatigue.
Depending in part on the particular design of the extruded metal honeycomb used to provide the heating element in assemblies such as above described, such elements can withstand more than 100 hours of exposure to the hot vibration test without damage to the electrical integrity of the heater element or enclosure.
A particular advantage of the axial canning method of the present invention is the degree of control over the cushioning of the heating element which can be achieved. The honeycomb heater acts as a suspended mass when the heater container is subjected to harsh vibration. When compressed properly, the resilient insulation serves as a mechanical suspension to dampen the honeycomb from harsh mechanical disturbances. The use of preloaded axial canning of the heater in accordance with the invention permits much greater control over the spring rate of the preloaded the insulation, and thereby greater control over the mechanical response of the honeycomb to the hot, mechanically severe environment of an automotive exhaust system. | A metal honeycomb heater is protectively mounted in an axially assembled enclosure comprising opposing tubular enclosure sections incorporating internal bore stops and a resilient mounting material to support the heater. An axial force of predetermined magnitude is applied to the sections during assembly, preloading the resilient mounting material and generating a selected spring tension and preloading force on the honeycomb. The sections are fastened together under this force so that the preloading force and spring tension are retained during subsequent use of the assembly. | 5 |
This is a 371 CPU/US93/03358 filed on Apr. 4, 1993 which is a continuation-in-part of U.S. patent application Ser. No. 07/865,850 filed Apr. 4, 1992 now U.S. Pat. No. 5,304,189.
BACKGROUND OF THE INVENTION
This invention is directed generally to rendering venous valve leaflets incompetent for in-situ arterial bypass in patients requiring arterial reconstruction for chronic limb-threatening ischemia. More particularly, this invention is directed to a venous valve cutter having unique improved cutting surfaces to facilitate the incision of the leaflets and a unique irrigation system to minimize frictional forces on the endothelium of the vein when introducing and withdrawing the cutter.
A common form of chronic limb-threatening ischemia, femorotibial, obstructive disease, typically is treated by using the greater saphenous vein as a bypass conduit. Traditionally, this vein has been removed from its anatomic bed and reversed to overcome the obstruction to flow from its one-way valves. The distal end of the "reversed flow" greater saphenous vein is then grafted to the femoral artery and its proximal end is grafted to the outflow artery beyond the obstruction.
There are a number of problems inherent in the use of a reversed flow saphenous vein as a bypass conduit. The narrow distal end of the vein may not permit enough arterial in-flow from its new parent vessel, whereas the wide proximal end of the vein makes an anastomosis to the 2-3 millimeter distal outflow vessel cumbersome. Also, the body of the vein may twist or compress and be damaged during the vein removal, reversal and replacement process and it is difficult to preserve the very sensitive endothelial layer of the vein during the removal and replacement process. Furthermore, the process may impair the blood vessel's blood supply (the vasa vasorum).
Bypass procedures in which a vein is used as it lies anatomically within the body, without removal, reversal and replacement, i.e., "in-situ situ vein bypasses", generally overcome most problems associated with removing, reversing and replacing the vein. This is most commonly accomplished in treating femorotibial disease by moving a valve cutter through the saphenous vein to incise the venous valve leaflets.
Since Carrel and Guthrie's publication of the techniques required for a small vessel anastomosis, vascular surgeons have attempted infrainguinal distal revascularizations. The advantage of the in-situ technique for saphenous vein bypass are first that the narrow end is anastomosed to the smaller artery distally with the graft tapering in the appropriate direction. This improves the hemodynamics at both anastomoses. A second consideration is that the adventitial blood supply to the vein is preserved to help protect the endothelial lining of the vein.
Typically, in performing this procedure either the distal end of the vein is anastomosed to the femoral artery to allow arterial blood to pass into the vein or a saline solution is pumped through a cannula into the vein to provide the required pressure to distend the vessel and close the valves. These procedures are performed to ensure that the valve cutter will meet and incise the valve leaflets in their closed, extended position. Once all of the valves are made incompetent, the vein becomes suitable for use as an arterial bypass conduit.
Unfortunately, it is quite difficult using currently available valve cutters, to efficiently and consistently incise and render the valves incompetent without damaging the endothelium of the vein or even piercing the vein wall. The various currently available valve cutter devices are difficult to manipulate, often do not center and catch the valve leaves properly, and can cause significant damage to the vein due to intimal contact between the surfaces of the cutting head and the vein wall and tearing at the points of valve attachment to the vessel wall.
U.S. Pat. No. 3,837,345, entitled "Venous Valve Snipper", describes a device for incising valves in vein grafts to bypass blocked arteries. This device is not intended to be used in-situ. The instrument has a closed position and an open position: it is maneuvered past the venous valves in the direction of blood flow, opened and withdrawn whereby sharp spikes spear and impale the venous valve leaflets which are then hopefully incised by closing the device in a scissors-like motion.
U.S. Pat. No. 4,493,321, entitled "Venous Valve Cutter for the Incision of Valve Leaflets In-situ", describes a valve cutter in the shape of a reverse arrowhead for preparing a vein in-situ for an arterial bypass. The valve cutter includes a rounded leader, a cutting blade enclosed in a protective support, a torsionally rigid rod connecting the leader to the cutting blade, and a catheter attached to the cutting blade support with suture material. The valve cutter is used by making proximal and distal incisions in the vein, passing a rod through the vein, attaching the valve cutter and pulling it down the vein while introducing fluid through the attached catheter to close the valves before incising them, and then returning the valve cutter assembly to the proximal incision. The orientation of this device must be continuously controlled to prevent the cutting blade from catching and tearing the orifice wall of a contributing venous branch and to ensure engagement and incision of both leaflets of each valve.
U.S. Pat. No. 5,047,041, entitled "Surgical Apparatus for the Excision of Vein Valves In-situ", describes a valve cutter in which a circular cutting head affixed to a cable is preceded by a dilating segment also affixed to the cable. The circular cutting edge has series of rounded guide teeth which are intended to guide the valve leaflets into cutting grooves which are supposed to engage and then cut the valve leaflets. Unfortunately, the rounded unsharpened guide teeth pull, stretch and likely irregularly tear the valve leaflets before any cutting can begin.
SUMMARY OF THE INVENTION
Accordingly, this invention is directed to an improved venous valve cutter for in-situ incision of valve leaflets which safely, efficiently, and consistently renders the venous valves incompetent while minimizing frictional forces on the endothelium of the vessel and preventing inadvertent contact between cutting surfaces and the intima of the vein wall.
An important object of this invention is the provision of a venous valve cutter for in-situ incision of valve leaflets which does not pull, stretch or tear the leaflets' attachments to the vessel wall.
Another important object of this invention is the rendering of the venous valves incompetent for in-situ arterial bypass by cutting blades which engage and penetrate the valve leaflets immediately on contact with the cutting head.
A further object of this invention is the provision of a venous valve cutter with interchangeable cutting heads which enable the surgeon to appropriately match the head size to a vessel's tapering lumen.
Yet another object of this invention is the provision of an integral venous valve cutter irrigation system which helps center the device while irrigating and opening the valves and distending the lumen of the vessel to prevent contact with the vessel wall as the device is passed up through the vessel in preparation for the valve cutting procedure.
Still another object of this invention is the provision of a valve cutter with an irrigation system in which fluid is allowed to pass retrograde into the cutter head of the device to flush and lubricate its cutting surfaces.
Yet a further object of the invention is to provide a venous valve cutter having a cutting head with a cylindrical portion which helps center the cutter in the vein.
Yet another object of the invention is to provide a venous valve cutter having a cutting head with a cylindrical portion in which channels are provided to facilitate fluid passage in tightly fitting vessels.
The improved venous valve cutter of the present invention includes, as a key feature, a cutter head having a plurality of generally proximally directed prongs separated by slots, where the prongs have flat forward cutting edges and the slots also have cutting edges along their entire length so that the prongs first pierce the valve leaflets whereupon the cutting surfaces of the slots continue the shearing action as the cutter moves through the valve. The present invention further includes a unique irrigation system for valve cutters in which saline or other fluid passes through the cutter head as the cutter moves through the vessel, first to minimize trauma as the cutter is passed through the vessel and the valves and then to minimize trauma and enhance the effectiveness of the shearing action as the valve leaflets are cut.
BRIEF DESCRIPTION OF THE FIGURES
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a front plan view of a horizontally disposed, improved venous valve cutter in accordance with the present invention;
FIG. 2 is an enlarged view of the cutter head and leader of the valve cutter of FIG. 1;
FIG. 3 is an enlarged end view, in elevation, of the cutter head of FIG. 1, viewing the cutter head from the pronged end;
FIG. 3A is a modified enlarged end view, in elevation, of the cutter head of FIG. 1, viewing the cutter head from the pronged end in which channels are provided to facilitate fluid passage in tightly fitting vessels;
FIG. 4 is an enlarged elevation view of the cutter head of FIG. 1, shown in section, taken along lines 4--4 of FIG. 3;
FIG. 4A is a schematic representation of a interchangeable valve cutter head;
FIG. 4B is an elevation view of a blunt-tipped head used to facilitate placement of the venous valve cutter when interchangeable cutting heads are to be used;
FIGS. 4C and 4D are elevation views of an alternative unitary interchangeable valve cutter head and leader design and FIG. 4E is an elevation view of alternate catheter design which may be fitted to the valve cutter head and leader of FIGS. 4C and 4D as well as that of FIG. 9 below;
FIG. 5 is an enlarged view of the cutter and leader assembly portion of the device of FIG. 1, shown in section, taken along lines 5--5 of FIG. 2;
FIG. 5A is an enlarged view of the cutter and leader assembly portion of the device of FIG. 1, shown in section, taken along lines 5--5 of FIG. 2 in which optional irrigation ports are formed in the cutter head and in the cutter stem.
FIGS. 6A-6I comprise a diagrammatic representation of the operation of the valve cutter of FIG. 1;
FIG. 7 is a planar representation of the continuous cutting surface of the present invention;
FIG. 8 is an enlarged front plan view, shown in section, of a cutter head in accordance with the present invention, in which provision is made for back flushing the cutter head as the valve leaflets are excised; and
FIG. 9 is an enlarged partial view of an alternative embodiment of the improved venous valve cutter of the present invention in which a fiber optic element is provided for viewing the vessel and the action of the cutting head in rendering the valves incompetent, and for assessing the effectiveness of the cut.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An improved venous valve cutter or valvulotome in accordance with the present invention is generally designated in FIG. 1 by the numeral 10. Although the valve cutter is discussed below in connection with in-situ bypass procedures, it is not limited to this and may be applied to any vascular operation requiring a non-reversed vein graft. Such applications may, for example, be found during distal infrainguinal bypasses when a non-anatomic position is required (ex: profunda femoris to anterior tibial artery), composite vein infrainguinal bypasses, or even an aorta-renal bypass.
Valve cutter 10 comprises a cutter head 12, a leader 14, a stem 15 between the cutter head and the leader, a catheter 16, a handle 18 and a combination hub and injection port 20.
Cutting head 12 may be made of any material which is safe for use in the body and is capable of taking and holding a knife edge. Stainless steel is preferred for the fabrication of the cutting head. The valve cutter may, for example, include 1.5 mm, 2.4 mm, 3.0 mm, and 4.0 mm or other size diameter cutting heads. The choice of cutter head size is a matter of judgement although it is recommended that a size smaller than the vein be employed.
Turning now to FIG. 2, an enlarged view of cutter 12 joined to leader 14 by stem 15 is shown. The distal end of cutter 12 is in the shape of a cone 22 truncated and bored at its distal tip 24 to provide an irrigation port 26 which communicates with a central lumen 27 (FIGS. 4 and 5). The edge 28 of irrigation port 26 preferably is rounded in order to minimize the danger of intimal damage.
Immediately proximal to cone 22, the cutter head surface flows smoothly into a first cylindrical section 30 which is undercut along its circumference at 32 to form a second cylindrical section 34 of slightly lesser outer diameter than the first cylindrical section. This undercut further minimizes the danger of damage to the vein wall as the cutter moves past the valves.
A plurality of proximally directed prongs 36 are at the proximal or "business end" of cylindrical section 34. At least two prongs are required, although four prongs, 36A, 36B, 36C and 36D are depicted in the illustrated preferred embodiment, and more can be used. The prongs are defined by half-oval slots 38 in cylindrical section 34.
The inside edges of prongs 36A-36D, as defined by slots 38, are bevelled back to a margin 40 and ground to present sharp cutting surfaces 41, as best seen in FIG. 4. Additionally, the flat leading edges 42 of the prongs are ground on their inner surfaces at 44 to similarly present sharp cutting edges. Thus, cutting head 12 is provided with a continuous cutting surface in multiple planes running along the entire forward edge 46 of the cutting head, which is shown in FIG. 7 as if the wall of the cutter were laid out in a plane. As a result, flat leading edges 42 of the prongs pierce the leaflets whereupon the eight sharp cutting surfaces 41 continue the shear of the venous valves as the cutter is pulled through to gently widen the cut in the valve until the apices 43 of the slots are reached whereupon the entire valve can be cleanly cored out and captured in the cutter head at 45 (FIG. 5).
The use of leader 14 is preferred but not required in the practice of the invention. Leader 14 is attached to cutter head 12 through a rigid stem 15, which is centered on the axis of both the cutter and the leader and forms an open lumen from irrigation port 26 through the distal end 50 of the leader, as seen in FIG. 5. Also, a rigid spring may be used as stem 15 to provide an additional irrigation site through the spacings between the coils of the spring. Finally, stem 15 must be of a length sufficient to permit the valve leaflets to close (clear the leader) before meeting the leading edges 42 of prongs 38A-38D.
Leader 14 includes a conical surface 70 which flows into a cylindrical surface 72 and then a trailing conical surface 76. A nipple 78 is provided at the proximal end of the leader for attachment to catheter 16.
In an alternate embodiment, catheter 16 comprises a tightly wound coil spring covered with an inextensible sheath. The coil spring is preferably stainless steel and the sheath is preferably a low surface friction thromboresistant material such as polyurethane. This sheathed coil structure is conformable, compliant and flexible yet has longitudinal rigidity for better centering.
Catheter 16 is attached to plastic handle 18 which may be made of polyurethane or other suitable materials. The surgeon will grip this handle as the device is passed through the vein, and may rotate the cutter head, if desired. However, even without physically rotating the device, the advancing cutting edges of the prongs produce incisions that advance about the valve leaflets in a circumvolutory fashion.
The hub/injection port 20 is attached to a source of saline (not shown). The saline or other fluid flows from the irrigation port distending the vessel's lumen and aiding in the centering of the device while irrigating and opening the valves as the valve cutter is passed up through the vessel in preparation for the valve cutting procedure. This minimizes trauma to the vessel wall, to preserve a viable, untraumatized and hence non-thrombogenic endothelium. In an alternative embodiment, depicted in FIG. 5A, irrigation ports 21 could be formed in cone 22 or in stem 15 to either enhance the effect of the irrigation from irrigation port 26 or to replace port 26 which could be capped off.
The present valve cutter adds a particular advantage over other such devices if the proximal anastomosis is not performed prior to rendering the valves incompetent since this permits the valve cutter to ensure that the valves are closed and thus the valves' maximum surface area is exposed for the cutting blade to engage the valves.
Further, the present valve cutter allows, with a small fiber optic bundle inserted through the irrigation channel in the valve cutter, direct observation of the incised valves. In an alternate embodiment, as illustrated in FIG. 9, a fiber optic bundle 154 is mounted in the leader 14 of the valve cutter to enable the surgeon to view and monitor the action of the cutting surfaces as they render each successive valve incompetent.
In yet another embodiment of the invention, underside irrigation is used in a valve cutter 12A as depicted in FIG. 8. In this embodiment, saline or other fluid is passed through the catheter 100 and into the rearward section 102 of the cutting head. The saline accumulates at 102 and is forced out through ports 104 to flush and lubricate the cutting edges of the cutting head as they cut into the valve leaflets.
Turning now to FIGS. 6A-6I, valve cutter 10 is introduced through the proximal end 110 of vein 112 and heparinized saline 114 is irrigated through port 26 in the cutting head of the valve cutter to dilate and lubricate vein 112 before the advancing cutting head which is shown passing up through valve 116, comprising leaflets 116A and 116B, in FIGS. 6B and 6C. The pressure gradient established through irrigation port 26 opens the valve leaflets ahead of the advancing valve cutter (FIG. 6B) which then passes through the valve as shown in FIG. 6C, well lubricated by the saline front advancing ahead of it.
When the cutting head of the valve cutter has cleared the valves, its direction is reversed (FIGS. 6D-6H). The valve cutter is thus positioned at the most proximal aspect of the vein and gently the hydrostatic pressure is re-established to close the nearest proximal valve. The irrigation pressure gradient should be gentle to prevent or minimize hydrostatic pressure injuries as the valve cutter is gently advanced, with the vein distended, allowing it to float proximally. The hydrostatic pressure is maintained so that, with the leaflets closed, leading edges 42 of the cutting head prongs engage the leaflets near the vein wall and immediately pierce them forming a small incision which is gently widened by the curved cutting surfaces 41 (FIGS. 6F-6H) until the valve is rendered incompetent leaving a clean and minimally damaged former valve site, as seen in FIG. 6I. The irrigation during the process is provided at a level sufficient to help center the device while minimizing the danger of hydrostatic pressure injuries to the vein.
The valve cutter 10 is then positioned at the most distal aspect of the next valve and gently the hydrostatic pressure is re-established to close that valve which is engaged and gently incised out as described above. Hydrostatic pressure is maintained and the valve cutter is pulled down, sequentially engaging and cutting the next distal valve until all the valves have been rendered incompetent.
If the surgeon wishes to construct a proximal anastomosis prior to using the valve cutter, thereby allowing the systemic arterial pressure to close the valves, the irrigation port may be capped off to prevent loss of blood. However, the proximal anastomosis does not negate the advantage of irrigation during the initial introduction of the valve cutter at the distal end of the vein. Also, the surgeon may wish to pass a fiber optic bundle through the irritation channel to view the cutting of the valves as the valve cutter proceeds down the vein.
In an alternative embodiment of the invention, as illustrated in FIG. 3A, channels 110-110D are provided in the cylindrical portion 30 of the cutter head to permit fluid flow when the cutter head encounters a tightly fitting portion of a vessel thereby preventing undesirable pressure build up and ensuring continued lubrication as the cutter passes through the snugly fitting portion of the vessel.
In yet another alternate embodiment of the invention, a series of differently sized cutter heads are provided in a kit with a single valve cutter assembly. This embodiment of the invention is depicted in FIG. 4A by a representative interchangeable cutter head 120 which has an inner female threaded portion 122 dimensioned to screw onto a corresponding male threaded portion 124 at the distal end of stem 126 of the valve cutter assembly. Thus, differently sized cutter heads with inner threaded female portions could be substituted for cutter head 120, along with a blunt-tipped head to facilitate initial placement of the device. The blunt-tipped head 130, which is illustrated in FIG. 4B, includes a body 132 having a blunt portion 134 and an irrigation port 134, and an internally threaded portion 135.
An alternative unitary interchangeable cutter head and leader 136 is illustrated in FIG. 4C. It includes a leader 138 with an inner female threaded portion 138 dimensioned to screw onto the corresponding male threaded portion 140 at the end of catheter 142 (FIG. 4D).
Use of the interchangeable valve cutter heads of FIGS. 4A-4C begins by introducing the valve cutter assembly fitted with the blunt-tipped head 130 through the most proximal end of the vein while heparinized saline is irrigated through the port to dilate the vein prior to advancing the device distally. The distal end of the vein is gently closed with a clamp or between the fingers of an assistant to allow for the dilation of the vein. With the vein distended, the valvulotome is gently advanced allowing it to float distally. When the catheter reaches the open sapheno-femoral junction, (or is passed out through a distal adequate tributary when the distal anastamosis is performed prior to the valve disruption procedure) the blunt tip head is removed and replaced with an appropriately sized valve cutter head. The saphenous vein is again clamped at its open fossa ovalis. The surgeon must choose a cutting head appropriate for the size of the patient's greater saphenous vein.
The valve cutter is then positioned at the most distal aspect of the vein. Fluid is injected through the catheter which distends the lumen and passes back over the cutting head and closes the valve which is now appropriately positioned for cutting. The fluid is injected to present a dilated vessel for the floatation of the device and a functionally closed valve for the cutting head to engage.
The valve cutter is withdrawn thus engaging and cutting the most distal valve. Slow and consistent traction is all that is required. The hydrostatic pressure is maintained and the valve cutter assembly is pulled down engaging and cutting each sequential valve, until all valves have been rendered incompetent within the appropriate range relative to the chosen cutting head. Judgment of the surgeon best determines when the catheter is again passed back through the unclamped distal sapheno-femoral junction where the cutting head is replaced with a larger head.
The procedure is repeated and again judgment determines the appropriately sized cutting head for the vessel's lumen. The appropriately sized valve cutting head will best cut the valves at a given position in the vessel. Preferred cutting head sizes include 1.5 mm, 2.4 mm, 3.0 mm and 4.0 mm. The choice of the particular size is a matter of judgement although it is recommended that a size smaller than the vein be employed. The ability to change cutting heads in this catheter allows the surgeon to appropriately match the heads to the vessel's tapering lumen.
Finally, current devices fitted with fiber optic elements at best permit the surgeon to view the valve distally and do not permit the cutting edge to be viewed as it penetrates the valve because the vessel collapses as the cutter penetrates through the valves. As illustrated in FIG. 9, in the present device the valve can be visualized proximately so that the cutting edge can be observed as it penetrates without the vessel collapsing. In this manner, each and every valve can be observed by the surgeon as the cutter edge penetrates.
Thus, FIG. 9 illustrates an enlarged partial view of an alternative embodiment of the improved venous valve cutter of the present invention in which a fiber optic element is provided for viewing the vessel, the action of the cutting head in rendering the valves incompetent, and for assessing the effectiveness of the cut. In this embodiment, the cutting end 150 of the cutter head is fixed to a leader 152 in which a fiber optic element 154 is mounted. This unique fiber optic mounting permits the surgeon to observe the cutting edge of the cutter head as it penetrates each valve using conventional apparatus (not shown).
It should be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore, intended that such changes and modifications be covered by the following claims. | An improved valve cutter for in-situ incision of valve leaflets which safely, efficiently, and consistently renders venous valves incompetent while minimizing frictional forces on the endothelium of the vessel and preventing inadvertent contact between cutting surfaces and the intima of the vein wall. The valve cutter includes a plurality of proximally directed prongs presenting sharp edges, where the prongs are separated by slots similarly presenting sharp edges to pierce the valve leaflets so that the cutting head is provided with a continuous cutting surface in multiple planes running along the entire forward edge of the cutting head. Fiber optics provided for viewing the valves as they are penetrated by the sharp cutting edges. | 0 |
TECHNICAL FIELD
[0001] The present invention relates in general to wellbore operations and in particular to fluids for drilling and stimulating or fracturing a reservoir formation.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] In general, distinctly different fluid systems are required to perform wellbore drilling operations and the stimulation operations such as reservoir fracturing. Drilling fluids become laden with drilled-rock particles and additives. Fracturing fluids are designed to be free of undesirable solids and additives that might reduce permeability and/or porosity of the stimulated formation and hydraulically generated fractures. It is a desired to provide a fluid that may be utilized as a drilling fluid and as a stimulation or fracturing fluid.
SUMMARY
[0004] In view of the foregoing and other considerations, the present invention relates to performing more than one wellbore operation without displacement of the working fluid to a secondary fluid system.
[0005] Accordingly, methods for using a single fluid to drill and fracture a well are provided. One method of fracturing a subterranean formation while drilling a well includes the steps of drilling a wellbore into a reservoir formation with a fluid, acidizing the fluid, and pressurizing the fluid to create a fracture in the subterranean formation.
[0006] Another method of fracturing a subterranean formation while drilling a well includes the steps of preparing a fluid with acid soluble additive(s) for drilling a wellbore into the formation; drilling the wellbore into the formation with the fluid; acidizing the fluid such that the acid soluble additive(s) will be degraded; and fracturing the formation with the fluid in the wellbore to create a channel in the formation.
[0007] Another method of fracturing a subterranean formation while drilling a wellbore includes the steps of preparing a dual-use fluid including an oleaginous fluid, a non-oleaginous fluid, and an amine surfactant; drilling a wellbore into a formation utilizing the dual-use fluid; adding a solid acid-precursor in the dual-use fluid; fracturing the formation utilizing the dual-use fluid in the wellbore; and generating acid in the dual-use fluid after the step of hydraulically fracturing the wellbore thereby converting the dual-use fluid from a water-in-oil emulsion to an oil-in-water emulsion and dissolving acid soluble components. For this or any other embodiment of the invention, acid soluble additives may be optionally, or may not be added to the dual-use fluid before drilling the wellbore.
[0008] Yet another method of method of fracturing a subterranean formation while drilling a well includes preparing a dual use fluid that is useful for drilling a wellbore into the formation; drilling a wellbore into the reservoir formation with the dual-use fluid; then, adding a solid-acid precursor to the fluid followed by fracturing the formation utilizing the dual-use fluid in the wellbore. Then, acid is generated from the solid acid precursor acid in the dual-use fluid after hydraulically fracturing the wellbore, the acid thereby dissolving drilling additives in response to generating acid.
[0009] Another method of fracturing a subterranean formation while drilling a well includes preparing a dual use fluid comprising a solid-acid precursor, then drilling a wellbore into a reservoir formation utilizing the dual-use fluid. The formation is then fractured utilizing the dual-use fluid, and acid generated in the dual-use fluid after the step of hydraulically fracturing the wellbore to dissolve drilling additives.
[0010] The methods and compositions of the invention may be used in any suitable downhole environment and formation geology, including those where the reservoir formation is predominately one of a carbonate formation, sandstone formation, or shale formation.
[0011] The foregoing has outlined some of the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 is a schematic illustration of an example of a dual-purpose fluid system.
DETAILED DESCRIPTION
[0014] At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation—specific decisions must be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The description and examples are presented solely for the purpose of illustrating the preferred embodiments of the invention and should not be construed as a limitation to the scope and applicability of the invention. While the compositions according to the invention are described herein as comprising certain materials, it should be understood that the composition could optionally comprise two or more chemically different materials. In addition, the composition can also comprise some components other than the ones already cited. In the summary of the invention and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors possession of the entire range and all points within the range.
[0015] Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
[0016] As used herein, the terms “up” and “down”; “upper” and “lower”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements of the embodiments of the invention. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth of the well being the lowest point.
[0017] FIG. 1 is schematic illustration of a dual-use fluid system of the present invention, generally denoted by the numeral 10 , being utilized to drill and fracture a well. A drilling rig 12 is positioned at the surface 14 for drilling a wellbore 16 into one or more subterranean reservoir formations 18 . In the described example, formation 18 is a carbonate reservoir formation, however, it is noted that system 10 may be utilized for other formation material.
[0018] In the illustration, a pipe string 20 having a drill bit 22 is utilized to drill wellbore 16 . Dual-use fluid 24 is in fluid connection with a fluid handling system generally denoted by the numeral 26 . Fluid handling system 26 may include numerous elements such as pumps, tanks, pits, mixers, shale shakers and the like.
[0019] Dual-use fluid 24 is adapted to be utilized to as a drilling fluid for drilling wellbore 16 and as a fracturing fluid to form fractures or channels 28 in formation 18 , for example in a fracturing while drilling operation. Fluid 24 may be a water-based fluid, oil-based fluid, or a reversible phase emulsion fluid. A reversible phase emulsion fluid may be changed between a water-in-oil emulsion, an oil-in-water emulsion, or a simple mixture of water and oil. Dual-use fluid 24 will be described herein with reference to reversible phase fluids and water-based fluids.
[0020] Some additives used in some embodiments of the invention may be acid soluble additives, including, but not limited to, weighting agents, fluid loss control material, filter cake control agents, viscosifiers, wetting agents, bridging agents and the like may be added to fluid 24 to adapt it for drilling wellbore 16 . Other additives and chemicals that are known to be commonly used in oilfield applications by those skilled in the art, which may or may not be acid soluble, may be used as well, in some embodiments. These include, but are not necessarily limited to, breaker aids, amino acids, oxygen scavengers, alcohols, scale inhibitors, corrosion inhibitors, bactericides, iron control agents, organic solvents, and the like.
[0021] For fracturing the subterranean formation, acid is added to fluid 24 to adapt it to use as a fracturing fluid. Desirably fluid 24 is acidized in fracture 28 or proximate to the formation of fracture 28 . By acidizing fluid 24 the acid soluble additives are dissolved thus limiting plugging or the formation or the fractures by use of fluid 24 from the drilling step. The acid soluble drill cuttings may also be reduced or eliminated by the acidizing of fluid 24 . Additionally, when fluid 24 is a reversible phase fluid, the step of acidizing fluid 24 causes the phase of fluid 24 to be changed.
[0022] A proppant may also be added to fluid 24 for maintaining the created channels 28 . It is noted that dual-use fluid 24 facilitates both drilling wellbore 16 and fracturing formation 18 with fluid 24 without displacement of dual-use fluid 24 to a secondary fluid system or the use of a different fracturing fluid from the drilling fluid. Proppant particles are substantially insoluble in the fluids of the formation. Proppant particles carried by the treatment fluid remain in the fracture created, thus propping open the fracture when the fracturing pressure is released and the well is put into production. Suitable proppant materials include, but are not limited to, sand, walnut shells, sintered bauxite, glass beads, ceramic materials, naturally occurring materials, or similar materials. Mixtures of proppants can be used as well. If sand is used, it will typically be from about 20 to about 100 U.S. Standard Mesh (approx. 0.84 mm to 0.15 mm) in size. Naturally occurring materials may be underived and/or unprocessed naturally occurring materials, as well as materials based on naturally occurring materials that have been processed and/or derived. Suitable examples of naturally occurring particulate materials for use as proppants include, but are not necessarily limited to: ground or crushed shells of nuts such as walnut, coconut, pecan, almond, ivory nut, brazil nut, etc.; ground or crushed seed shells (including fruit pits) of seeds of fruits such as plum, olive, peach, cherry, apricot, etc.; ground or crushed seed shells of other plants such as maize (e.g., corn cobs or corn kernels), etc.; processed wood materials such as those derived from woods such as oak, hickory, walnut, poplar, mahogany, etc. including such woods that have been processed by grinding, chipping, or other form of particalization, processing, etc. Further information on nuts and composition thereof may be found in Encyclopedia of Chemical Technology, Edited by Raymond E. Kirk and Donald F. Othmer, Third Edition, John Wiley & Sons, Volume 16, pages 248-273 (entitled “Nuts”), Copyright 1981, which is incorporated herein by reference. The concentration of proppant in the fluid can be any concentration known in the art, and, as an example, may be in the range of from about 0.05 to about 3 kilograms of proppant added per liter of liquid phase. Also, any of the proppant particles can further be coated with a resin to potentially improve the strength, clustering ability, and flow back properties of the proppant.
[0023] When fluid 24 is a reversible phase fluid, it includes an oleaginous fluid, a non-oleaginous fluid and an amine surfactant. The oleaginous fluid may be diesel oil, mineral oil, a synthetic oil and suitable combinations of these and may include at least 5% of a material selected form the group including esters, ethers, acetals, dialkylcarbonates, hydrocarbons and combinations thereof. The non-oleaginous fluid may be an aqueous liquid which may be selected from the group including fresh water, produced water, sea water, brine containing organic and/or inorganic dissolved salts, an aqueous solution containing water-miscible organic compounds, or combinations of these.
[0024] Reversible phase fluid 24 may be an invert emulsion, water-in-oil emulsion, for the drilling step of the operation. The invert emulsion fluid may contain a weighting agent, a bridging agent and/or other additives that are acid soluble. The weighting agents and/or bridging agents may be selected from the group including calcium carbonate, dolomite, siderite, barite, celestite, iron oxides, manganese oxides, ulexite, carnalite, and sodium chloride.
[0025] Upon completion of the drilling step and in preparation for fracturing formation 18 , reversible phase fluid 24 may be converted from an invert emulsion to a direct emulsion or simply a water and oil mixture. In the present example, the invert emulsion is admixed with an acid that is functionally able to protonate the amine surfactant. When sufficient quantities of the acid are utilized, the invert emulsion is converted so that the oleaginous fluid becomes the discontinuous phase and the non-oleaginous fluid becomes the continuous phase. The conversion of the phases may be reversible so that upon addition of a base capable of deprotonating the protonated amine surfactant, a stable invert emulsion in which the oleaginous liquid becomes the continuous phase and the non-oleaginous fluid become the discontinuous phase can be formed.
[0026] The acid further prepares dual-use fluid 24 for use in fracturing formation 18 by degrading various additives that were utilized in the drilling step. Additionally, the acid eliminates at least a portion of the cuttings carried by fluid 24 , in particular when the formation is carbonate.
[0027] Compounds that are suitable for use as an acid include mineral acids and organic acids preferably soluble in water. Mineral acids include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid and the like. Organic acids include citric acid, tartaric acid, acetic acid, propionic acid, glycolic acid, lactic acid, halogenated acetic acids, butyric acid, organosulfonic acids, organophosphoric acids, and the like. Compounds that generate acid upon dissolution in water may also be used, for example, acetic anhydride, hydrolyzable esters, hydrolyzable organosulfonic acid derivatives, hydrolyzable organophosphoric acid derivatives, phosphorus trihalide, phosphorous oxyhalide, anhydrous metal halides, sulfur dioxide, nitrogen oxides, carbon dioxide, and similar such compounds. Typically, fatty acids should be avoided or used in small amounts so as to not interfere with the reversibility of the amine surfactant system.
[0028] Excellent sources of acid that can be generated downhole when and where it is needed are solid cyclic dimers, or solid polymers, of certain organic acids, that hydrolyze under known and controllable conditions of temperature, time and pH to form the organic acids. One example of a suitable solid acid is the solid cyclic dimer of lactic acid (known as “lactide”), which has a melting point of 95 to 125 degrees Celsius, (depending upon the optical activity). Another is a polymer of lactic acid, (sometimes called a polylactic acid (or “PLA”), or a polylactate, or a polylactide). Another example is the solid cyclic dimer of glycolic acid (known as “glycolide”), which has a melting point of about 86 degrees Celsius. Yet another example is a polymer of glycolic acid (hydroxyacetic acid), also known as polyglycolic acid (“PGA”), or polyglycolide. Another example is a copolymer of lactic acid and glycolic acid. These polymers and copolymers are polyesters.
[0029] It has been found that dissolution of the solid acid-precursors may be accelerated by the addition of certain chemical agents. These agents react readily with the solid acid-precursor and cause the removal of a small amount of material from the solid acid-precursor surface. Note that the formation itself can be a solid accelerant. Furthermore, the action of accelerants may be delayed, for example, if the are slowly soluble solids or if they are chemically bound in a liquid chemical that must be hydrolyzed to release the agent. One solid acid-precursor may be an accelerant for another; for example, PGA accelerates the hydrolysis of PLA. The timing and rate of dissolution of the solid acid-precursor is controlled by these techniques.
[0030] To accelerate the dissolution of solid acid-precursors, water-insoluble solid acid-soluble or acid-reactive materials, such as but not limited to magnesium hydroxide, magnesium carbonate, dolomite (magnesium calcium carbonate), calcium carbonate, aluminum hydroxide, calcium oxalate, calcium phosphate, aluminum metaphosphate, sodium zinc potassium polyphosphate glass, and sodium calcium magnesium polyphosphate glass, may be mixed with or incorporated into, solid acid-precursors, such as cyclic ester dimers of lactic acid or glycolic acid or homopolymers or copolymers of lactic acid or glycolic acid. These mixtures are added to the fracturing fluid. At least a portion of the solid acid-precursor slowly hydrolyzes at controllable rates to release acids at pre-selected locations and times in fracture 28 .
[0031] The acids react with and dissolve at least a portion of the acid-reactive materials. This accelerates the dissolution of the solid acid-precursor and generates acid in amounts beyond that which reacts with the solid acid-reactive material(s). The result is that at least a portion of both the solid acid-precursor and the acid-reactive solid material dissolve. Usually most or all of the solid material initially added is no longer present at the end of the treatment. However, it is not necessary either for all of the solid acid-precursor to hydrolyze or for all of the solid acid-reactive material to dissolve. Any solids remaining will beneficially act as proppant. Note that often the additional solid acid-reactive material will not be needed to accelerate the hydrolysis of the solid acid-precursor, because the formation itself will be acid-reactive. However, the solid acid-reactive material may be selected to be more reactive than the formation or may be in more intimate contact with the solid acid-precursor.
[0032] The dissolution of solid acid-precursors in acid fracturing may also be accelerated by the addition of certain soluble liquid additives. These accelerants may be acids, bases, or sources of acids or bases. These are particularly valuable at low temperatures (for example below about 135 degrees Celsius), at which the solid acid-precursors hydrolyze slowly, relative to the time an operator would like to put a well on production after a fracturing treatment. Non-limiting examples of such soluble liquid additives that hydrolyze to release organic acids are esters (including cyclic esters), diesters, anhydrides, lactones and amides. A compound of this type, and the proper amount, that hydrolyzes at the appropriate rate for the temperature of the formation and the pH of the fracturing fluid is readily identified for a given treatment by simple laboratory hydrolysis experiments. Other suitable soluble liquid additives are simple bases. (They are termed “liquids” because in practice it would be simpler and safer to add them to the fracturing fluid as aqueous solutions rather than as solids.) Suitable bases are sodium hydroxide, potassium hydroxide, and ammonium hydroxide. Other suitable soluble liquid additives are alkoxides, water-soluble carbonates and bicarbonates, alcohols such as but not limited to methanol and ethanol, alkanol amines and organic amines such monoethanol amine and methyl amine. Other suitable soluble liquid additives are acids, such as but not limited to hydrochloric acid, hydrofluoric acid, ammonium bifluoride, formic acid, acetic acid, lactic acid, glycolic acid, aminopolycarboxylic acids (such as but not limited to hydroxyethyliminodiacetic acid), polyaminopolycarboxylic acids (such as but not limited to hydroxyethylethylenediaminetriacetic acid), salts—including partial salts—of the organic acids (for example, ammonium, potassium or sodium salts), and mixtures of these acids or salts. (Ammonium bifluoride partially hydrolyzes in contact with water to form some HF, and so will be called an acid here.) The organic acids may be used as their salts. When corrosive acid might contact corrodible metal, corrosion inhibitors are added.
[0033] Mixtures of one or more solid acid-precursors and one or more solid acid-reactive materials, if they are present, may be purely physical mixtures of separate particles of the separate components. The mixtures may also be manufactured such that one or more solid acid-precursors and one or more solid acid-reactive materials is in each particle; this will be termed a “combined mixture”. This may be done, by non-limiting examples, by coating the acid-reactive material with the solid acid-precursor, or by heating a physical mixture until the solid acid-precursor melts, mixing thoroughly, cooling, and comminuting.
[0034] The solid acid-precursors or the mixtures of solid acid-precursors and solid acid-reactive materials may be manufactured in various solid shapes, including, but not limited to fibers, beads, films, ribbons and platelets. The solid acid-precursors or the mixtures of solid acid-precursors and solid acid-reactive materials may be coated to slow the hydrolysis. Suitable coatings include polycaprolate (a copolymer of glycolide and epsilon-caprolactone), and calcium stearate, both of which are hydrophobic. Polycaprolate itself slowly hydrolyzes. Generating a hydrophobic layer on the surface of the solid acid-precursors or the mixtures of solid acid-precursors and solid acid-reactive materials by any means delays the hydrolysis. Note that coating here may refer to encapsulation or simply to changing the surface by chemical reaction or by forming or adding a thin film of another material. Another suitable method of delaying the hydrolysis of the solid acid-precursor, and the release of acid, is to suspend the solid acid-precursor, optionally with a hydrophobic coating, in an oil or in the oil phase of an emulsion. The hydrolysis and acid release do not occur until water contacts the solid acid-precursor. Methods used to delay acid generation may be used in conjunction with inclusion of solid acid-reactive material to accelerate acid generation because it may be desirable to delay acid generation but then to have acid generated rapidly.
[0035] Examples of methods of fracturing a subterranean formation 18 that is in fluid communication with the surface 14 via a well is now described with reference to FIG. 1 . In one example, a wellbore 16 is drilled into a reservoir formation 18 with fluid 24 . An acid is added to fluid 24 and fluid 24 is pressurized causing formation 18 to fracture 28 . The acid may reverse the phase of fluid 24 as well as degrade additives and/or cuttings in fluid 24 .
[0036] From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a system and method for drilling a wellbore and fracturing a formation with substantial the same fluid that is novel has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow. | A method of fracturing a subterranean formation while drilling a well includes the steps of preparing a fluid useful for drilling a wellbore into the formation; drilling the wellbore into the formation with the fluid; acidizing the fluid such that the acid soluble additive is degraded; and fracturing the formation with the fluid in the wellbore to create a channel in the formation. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a bullet proof vest.
BACKGROUND OF THE INVENTION
[0002] Bullet proof vests have been used for a long time. However, many of such vests are heavy and uncomfortable to use. Conventional vests are often not as reliable when many shots are fired into them and the risk of injury to the wearer of the bullet proof vest increases. There is a need for a vest that protects against multiple bullets without overheating that reduces the protection. There is a need for a bullet proof vest that is comfortable and can handle a plurality of bullets without reduced protection provided by the vest. There is also a need for a vest that can easily be adjusted to the specific needs of the user so that more protection is provided in certain dangerous situations and less protection when there is less risk of being shot at with a heavy duty weapon.
SUMMARY OF THE INVENTION
[0003] The bullet proof vest of the present invention provides a solution to the above-mentioned problems. The method of the present invention is for safely receiving a bullet in a bullet proof vest. A plate structure is provided that has an airtight enclosure enclosing high performance fiber layers, a hard layer, a textile layer having openings defined therein and a semi-solid and sticky layer such as bitumen or rubber. A bullet may penetrate through the airtight enclosure. The pressure inside the airtight enclosure is increased as a result of the energy and heat of the bullet. The increased pressure increases the volume of the enclosure and separates the layers from the hard layer and the textile layer from the hard layer. The hard layer may be used to deform the bullet. The textile layer attaches to the bullet to follow the bullet as the bullet moves into the rubber layer. The semi-solid sticky layer sticks to the bullet as the bullet penetrates through the plate structure to further slow down the bullet. An air-bubble layer may transversely distribute the bullet impact. The vest of the present invention has convenient snap-on fasteners that make it easy to take on and take off the vest and to remove and insert the removable plates. More particularly, the vest has pockets defined therein so that the user may remove the plates and replace the plates with different plates by inserting the different plates into the pockets.
BRIEF DESCRIPTION OF THE DRAWING
[0004] FIG. 1 is a perspective front view of the vest of the present invention;
[0005] FIG. 2 is a perspective back view of the vest of the present invention;
[0006] FIG. 3 is a detailed cross-sectional view of a portion of an armor plate of the present invention; and
[0007] FIG. 4 is a detailed cross-sectional view of a portion of an armor plate of the present invention.
DETAILED DESCRIPTION
[0008] FIGS. 1-2 show a bullet proof vest 10 of the present invention that has a front body armor section 12 with shoulder straps 14 that have snap fasteners 16 for easy take off and fastening of the vest 10 . The front section 12 has an openable inside pocket 18 defined therein that extends across the entire front section 12 . The pocket 18 has an armor plate 20 disposed therein to provide bullet protection for the entire front page of the body of the wearer. The section 12 has an openable outside pocket 22 defined therein for holding an additional armor plate 24 .
[0009] Straps 26 , 28 enclose the vest 10 . The straps 26 , 28 have snap fasteners 30 , 32 for easy take-on and take-off of the vest. Extra side plates 34 , 36 may be disposed at the lower end of the vest in pockets 35 , 37 to provide extra protection for the kidney and other vital organs of the wearer. Snap-on double side plates 38 , 40 may extend downwardly or hang from a lower edge 42 of the vest to protect the hip area. The plates may be attached by a snap fastener 41 .
[0010] As best shown in FIG. 2 , the vest 10 also has a back body armor section 44 that are attached to the shoulder straps 14 with suitable fasteners 46 , 48 such a Velcro. The section 44 has an openable inside pocket 50 defined therein that extends across the entire back section 44 . The pocket 50 has an armor plate 52 disposed therein so that the armor plate is removable from and insertable into the pocket 50 .
[0011] The back section 44 may have a gas-mask bag 54 removably attached thereto by fasteners 56 such as Velcro so that it is easy to remove and attach the bag 54 . By placing the bag 54 on the back section 44 it is not in the way when the wearer must move quickly in dangerous situations. The back section 44 also has an openable pocket 58 defined therein for holding an extra armor plate 60 so that the plate 60 may easily be removed from and inserted into the pocket 58 .
[0012] FIG. 3 shows a detailed cross-sectional view of an armor plate 62 which could be identical to and used as the armor plates mentioned above. The plate 62 has an outside airtight elastic enclosure 64 that may be made of a suitable elastic polymer such as nylon that has glue on one side. A plurality of textile layers 66 , disposed inside and glued to the enclosure 64 , made of a high strength fiber such as aramid may be used. For example, the plate 62 could use about seven textile layers or any other suitable number of layers. A steel or polymer layer 68 may be disposed inside the textile layers 66 . Behind the layer 68 there is a polymeric net or woven layer 70 that may be a woven fiberglass or any other suitable material. A sticky and relatively soft rubber or bitumen material 72 is disposed behind the layer 70 . Any suitable semisolid and sticky material may be used as the material 72 . Another layer 74 , similar to the layer 70 , may be disposed behind the rubber material 72 followed by another sticky semi-solid material 76 similar to the material 72 . Another layer 78 , similar to the layers 70 , 74 , may be disposed behind the material 76 followed by a polymeric layer 80 that has air-bubbles 82 distributed across the layer 80 . The air-bubbles not only absorb and spread the penetration and impact forces over a bigger area but also provide insulation against over heating when the vest is hit by many bullets in a short period of time. High strength fiber layers 84 such as aramid may be disposed behind the layer 80 .
[0013] FIG. 4 shows an extra combination plate or trauma plate 86 that may be disposed behind the layers 84 or behind the entire plate 62 to provide extra protection and to make sure no bullet penetrates through the vest. The plate may have a plurality of high impact strength fiber textile layers 88 , such as aramid, and a polymeric layer 90 with air-bubbles 92 followed by layers 94 of high strength fiber textile, such as aramid.
[0014] In operation, a bullet hits the vest 10 and penetrates through the airtight enclosure 64 . The energy from the bullet generates hot gases that blow up the enclosure 64 somewhat to expand its volume and so that air gets in between the various layers of the plate 62 . Because the enclosure 64 is airtight, most of the gases remain inside the enclosure 64 and increases the pressure inside and the volume of the enclosure so that there is more room for the various layers to move relative to one another. The bullet may penetrate through the layers 66 that slow down the bullet and hits the steel layer 68 . The hard layer 68 further slows down and also deforms the bullet. The layers 66 may catch any ricocheting debris and other scrap parts from the bullet as the bullet is deformed against the steel plate 68 . This protects the environment and the wearer from being injured from any ricocheting debris. If the bullet has enough energy to penetrate through the plate 68 , the deformed bullet encounters the woven fabric or layer 70 . The woven layer 70 has holes defined therein and fibers of the layer 70 attaches to and follows the bullet as the bullet penetrates into the elastic, sticky and relatively soft rubber material 72 . A portion of the material 72 sticks to the outer surface of the bullet and the fibers from the layer 70 to further slow down the velocity of the bullet. The rubber material is deformable and allows a plurality of bullets to penetrate therein without losing the effectiveness of the sticky rubber material attaching to the bullets to slow down the bullets. The fact that the bullets have been deformed by the plate 68 and the attached woven layer 70 make it easier for the rubber material to stick to the bullet. As the bullet penetrates the rubber material 72 , the rubber material 72 is also heated by the heat of the bullet and the rubber material becomes stickier to further reduce the velocity of the bullet. The additional layers of the sticky rubber materials also stick to the already sticky outer surface of the bullet including the fibers from the layer 70 that are also stuck to the outer surface and rubber material on the bullet. The combination of the sticky rubber layers and the woven textile layer makes a substance that dramatically slows down the velocity of the bullet. Should the bullet penetrate through the layer 78 , the air bubbles 82 of the layer 80 transversely or sideways distribute and spread out the energy and penetration forces of the bullet to further reduce the impact of the bullet into the layers 84 . The burst air bubbles 82 create a layer of air that spreads the penetration forces and thus minimizes the trauma effect since the penetration is spread out over a much large areas. In this way, the penetration forces are further weakened and the bullet is not permitted to focus the penetration energy to a small area. The layers 84 are then enclosed by the airtight enclosure 64 .
[0015] An important feature of the present invention is that the various layers, except the enclosure 64 , are not glued to one another to permit air to be disposed between the layers as the enclosure 64 is gas filled by the energy of the penetrating bullet.
[0016] While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims. | The method is for receiving a bullet in a bullet proof vest. A plate structure is provided that has an airtight enclosure enclosing high performance fiber layers, a hard layer, a textile layer having openings defined therein and a semi-solid layer such as bitumen. A bullet penetrates through the airtight enclosure. The pressure inside the airtight enclosure is increased. The increased pressure separates the layers from the hard layer and the textile layer from the hard layer. The hard layer deforms the bullet. The textile layer attaches to the bullet to follow the bullet. The layer sticks to the bullet as the bullet penetrates through the plate structure. | 5 |
BACKGROUND OF THE INVENTION
Many synthetic cloth-like materials are available on the market. The synthetic materials are made of thermoplastic and formed as woven and non-woven types. Some of these synthetic cloths include materials generally known as "Tyvek", which is a trademark of E. I. Dupont de Nemours & Co., Wilmington, Del. 19898; "Duraguard" and safeguard", which are trademarks of Kimberley-Clark Corporation, Roswell, Georgia 30076; "Celestra", which is a trademark of Crown Zellerbach Corporation, Washougal, Wash. 98671; and "Duralace", which is a trademark of Chicopee Manufacturing Co., Chicopee, Ga. 30501. These materials are utilized as substitutes for cloth and pulp-paper in items such as envelopes and disposable clothes for medical, industrial and retail markets. Many such applications require that the material be joined at a seam, and in this respect some difficulty is encountered in the prior art.
In the prior art, the seams in the material for forming, for example, disposable coveralls are often formed by sewing it much like cloth, or by using adhesive, including heatsensitive adhesives. Sewing of the material causes pinholes which makes the completed item of clothing undesirable for use in dust-free and sterilized environments. Use of adhesives to form bonding requires special adhesives and complicates the manufacturing procedure. Furthermore, it is difficult to obtain a good seal bond along a seam by using adhesives.
In many instances the seal obtained exhibits a "zipper" effect, in that the seal has random intermittent breaks or weak points which affect the quality of the seal at the seam.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a heating and press die arrangement for forming seam seals free of "zipper" effect in sheets of thermoplastic material.
It is another object of this invention to control the size and shape of the seam seal by selecting the proper dimensions for a heating element in one of the die members, and for a matching recess in the other die member; and by correlating these dimensions to the thickness and compression of the thermoplastic sheet material.
It is still another object of the invention to form two adjacent seals, side by side, with a crimped or tear region therebetween, or to form edge joints or intermittent joints.
Another object of the invention is to relieve the tension between the seam seal and the seal-material interface to provide a more secure and strong bond.
A further object of the invention is to allow confined material to be heated from different directions, simultaneously or independently.
A still further object of the invention is to form a uniform seal bond by controlling the humidity at the workstation, the pressure applied to the confined material and the duration thereof, and the heat supplied and the duration thereof.
These and other objects are realized and distinct advantages obtained in the present invention.
The present invention is a method and apparatus for thermobonding thermoplastic cloth-like material along a seam. A support plate is provided for supporting sheets of thermo-plastic material to be bonded together and a heat element having a first cross-section is provided adjacent to, or in a seat in, the support plate. Pressure plate means are provided for mating with, and applying pressure to, the support plate. Recess means configured to receive the heat element means are provided adjacent to or with the pressure plate means. When the pressure plate means engages the support plate, the material sheets are confined and clamped therebetween.
In general cross-sectional configuration, the heat element means may comprise an arc of a circle and the recess means may comprise a similar arc of a circle or ellipse, rectangle, triangle, etc. When the relief means and the heat element means are in mating relationship, a melt zone comprising a void is formed therebetween. The melt zone is the region within which melted portions of the thermoplastic material can accumulate and be confined to form a seal. It is also a region that serves to relieve the stress between the seal and the material interface.
If two melt zone means are provided, a crimping region may be provided between them. At the crimping region a greater pressure is applied to cause a "draw down" (i.e. pull) of the material into neighboring melt zone means to form a tear.
If a crimping region is not desired, a round or flat ribbon with its ends rounded may be used as a heating element. The region of the rounded ends of the flat ribbon serves as the stress relieving region which relieves the stress between the melt and the melt-material interface. With the round wire as the heating element the dimensions of the recess means is selected to avoid the pressure bearing crimping zone.
The support plate and pressure plate means may be provided with insulating material which may optimally be slightly resilient to aid in clamping the sheets of the material therebetween. If the insulating material is formed as a teflon-impregnated fiberglass in the recess means, it would act as flow channel to control the melt flow of the material.
The length of heat element means may be contoured to form different shapes, for example, a glove. For such purposes, the cross-section of the heat element means may have a support portion to anchor it, and an outer exposed portion comprising an elongated member with rounded edges.
The heat element means may be configured to provide only an edge joint, lap joint, butt joint, intermittent lap, or intermittent edge joints.
The heat element means may be directly heated, i.e. it may comprise an electrically heated wire, or be indirectly heated through heating means imbedded adjacent thereto.
The recess means may be split i.e. formed as first and second recess means, each configured to mate with only a portion of the heat element means. With this configuration the crimping zone is absent, and the result is two neighboring bond seals (they may be parallel, but that is not essential).
The above heat element means and the recess means may be made in various sizes and shapes for thermoplastic sheets of different thickness, fabrication characteristic, and seam seal bond desired. With the proper heat element means and recess means, a good seam seal bond (i.e. one devoid of "zipper" effects) may be obtained by controlling the following factors:
(a) the humidity (H) of the workstation (assuming that the material is at substantially similar humidity). Preferably H should be between about 27 and about 52 percent.
(b) pressure (P) applied on the recess means when it is in mating relationship with the heat element means with the seam edge of the material clamped therebetween. Preferably P should be between about 20 and about 60 p.s.i.
(c) normal temperature setting (T) of the heat element means. Preferably T should be between about 58° F. and about 72° F.
(d) Raising the temperature of the heat element means to a range between a high (t h ) and a low (t 1 ). Preferably t h should be about 340° F. and t 1 should be about 125° F.
(e) time period (h t ) of supplied heat, i.e. the time during factor (d) above is active. Preferably h t should be between about 0.38 seconds and about 5.51 seconds.
(f) dwell time "d", for which factor (e) above is active plus time thereafter that the pressure factor (b) above is continued. In other words, dwell time "d" is the time period during which pressure P is applied.
The various materials with which the above method may be practiced are those similar to Dupont's 1085, Tyvek (1444, 144A and 1443R); Kimberley-Clark's Safeguard and Duraguard; Chicopee's Duralace, and American Converter's Evolution.
The invention can be better understood by referring to the drawings and the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of an arrangement of a die press containing the heat element to form seams.
FIG. 2 is a sectional view along line x--x of FIG. 1 showing various parts of the present invention.
FIG. 3a is an arrangement showing the mating relationship of the device of FIG. 2 and the melt zone means.
FIG. 3b is part of FIG. 3a showing the melt region and the melt-material interface.
FIG. 4 shows a perspective view of a seam seal formed by the apparatus of FIGS. 2 and 3.
FIG. 5a is a sectional view along line x--x of FIG. 1 showing another embodiment of the melt zone means.
FIG. 5b is FIG. 5a showing the melt region and the melt-material interface of the thermoplastic sheets.
FIGS. 6a-6d is a sectional view along line x--x of FIG. 1 showing a different embodiment of the melt zone means. It also shows split recess means.
FIG. 7 is still another embodiment of the melt zone means.
FIG. 8 is a perspective view of two sheets of the material with a dual seam.
FIG. 9a is another embodiment of heat element means and recess means for forming a single edge joint.
FIG. 9b is a perspective view of an edge seal.
FIG. 10a is a sectional view along line x--x of FIG. 1 showing a flat ribbon heat element means.
FIG. 10b is a perspective view of the joint formed by FIG. 10a.
FIGS. 10c-10d are sectional views along x--x of FIG. 1 showing a flat ribbon used to obtain dual seals.
FIG. 11a is a perspective view showing an intermittent edge joint.
FIG. 11b is a perspective view showing an intermittent lap joint.
FIGS. 12a and b are views of the heat element means showing its arrangement for forming intermittent joints.
FIG. 12c is a side view of the recess means showing its arrangement for forming intermittent joints.
FIG. 13 is a sectional view along line x--x of FIG. 1 showing heat element means particularly configured for seals having sharp bends.
FIG. 14 is a top view of the heat element means configured as a glove.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Initially it should be understood that the term "melt" used herein is intended to mean the state of the thermoplastic material where it plasticizes, and cross-linking between different layers occurs to where they are amenable to be bonded together. "Melt" for purposes of this disclosure does not require that the material liquify.
FIG. 1 generally shows an arrangement of a press die 10 having an upper portion 12 and a lower portion 14. FIGS. 2, 3, 5-7, 9 and 13 are sectional views along line x--x of FIG. 1. The lower portion 14 includes a support plate 16 for supporting sheets of thermoplastic material thereon, and heat element means 18. The heat element means may be situated in a seat 17 in the support plate 16. The heat element means may comprise, for example, a wire that is spring loaded and held taut. The heat element means has a support portion 18b held within the lower portion 14 (in the seat 17) and an exposed portion 18a. The support portion 18b has a surface area 18c sufficient to be affected by the heating/cooling system 28 so that the heat of the heat element means 18 may be controlled.
The upper portion 12 comprises pressure plate means 20 provided for mating with and applying pressure on the support plate 16 and thereby clamping the material therebetween, and recess means 24 configured to receive the heat element means 18. The recess means may be a relief formed in the pressure plate means. The pressure plate means is preferably made of a slightly resilient material. A backup plate 26 provides rigidity and support for the pressure plate 20. The heating/cooling system 28 adjacent the heat element means 18 controls the heat thereof. A layer of insulating semi-resilient material 38 (FIG. 2) may be provided on both the pressure plate means and the support plate 16. It is not essential that the elastomeric layer be present on both the pressure plate and the support plate, providing that only one of the two may suffice.
When the top and the bottom die are in an engaging or mating relationship, the heat element means 18 is received within the recess 24. The recess 24 is configured to apply a substantially crimping pressure at the point 33 and to leave a room or void 35 between the recess and the heat element means. The void 35 is the melt zone means and provides space for the material to melt and be contained to form a seal. Additionally the provision of the melt zone means serves to relieve tension and stress between the seal and the seal-material interface. The crimping zone 33 is a point where greater pressure is applied to cause the thermoplastic material 30 to be crimped. With the configuration of FIGS. 2 and 3 the resultant seal obtained is shown at FIG. 4. Two sheets of thermoplastic material 29 and 31 are joined at the region 36 which represents the seal formed in the melt zone means 35, and separated from each other at 34 which represents the region 33.
From the above it can be seen that the melt zone means is critical in terms of selecting the size and shape of the seal 36 to be formed. Assuming that A is the amount of the heat element means 18 that is retained within the seat 17 as measured from the outer surface of the support plate 16, and B represent the depth of the recess means 24, then a proper selection of A and B together with the dimensions for C and D and the shape of the heat element means 18 and recess means 24 will determine the shape and configuration of the melt zone means E. The triangular melt zone means E in FIG. 3 is only an illustration and not a representation of its shape or size. For purposes of this invention, the upper and lower portions 12 and 14 may be manufactured as replaceable and interchangeable die elements having different sizes and shapes. The proper die to be used will depend on the material and the seal desired.
In operation of the device of FIGS. 1-4, sheets of material 30 to be joined are placed and supported on the support plate 16, with the seam edge to be formed aligned with the heat element means 18. The upper portion 12 is brought into pressing engagement with the lower portion 14. The pressure plate 20 presses on the material 30 and the support plate 16 and clamps the material 30 therebetween. At the same time, the heat element means 18 with the material aligned therewith is received within the recess means 24. The depth to which the heat element is received within the recess means depends on the selection of dimensions for A and B for the particular material 30, the size and shape of the heat element means 18 and the type of seam seal bond desired, the thickness of the material and the compressibility thereof. The recess means 24 is of a dimension to allow slippage of the material 30 over the contour of the heat element means 18 and still maintain a clamping effect thereon. At the point 33 the material 30 may be compressed to a greater degree than in the region of the melt zone means 35. To effect a good clamping, the material outside of the melt zone 35 may be compressed 20% to 45% from the total material thickness. The maximum recess dimension in the melt zone region may be the total material thickness around the heat element means 18 to a minimum of 50% of the material thickness.
The material being considered here has a certain compression factor based on compressibility of the material, the pressure plate means and the resiliency thereof under various loading conditions. The compression factor may be stated as F. For material sheets formed of polyethylene the compression factor is 0.47, for polypropylene it is 0.52, and for rayon acrylic it is 0.42.
Other factors that must be considered in adjusting A, B, C, D and E are the total thickness of the sheets that are situated and confined between the heat element means and the recess means and the thickness of the heat element means. The total thickness (G) would be the sum total of the thickness of each of the sheets that are stacked to be joined. The thickness (H) of the heat element means determine the amount thereof (H-A) that will protrude from the outer surface of the support plate means.
The following formula can be used as a guide to set A, B, F and G.
B=H-A+G(F-1)
The temperature of heat element means is set for a certain high and low from its normal temperature at which it is maintained between operations. The pressure applied by the upper portion 12 is controlled and set differently depending on the material involved. A stop clock (not shown) is provided to set the heat time, i.e. the time period for which heat is applied by the heat element means to the material 30. Another clock setting provides the heat dwell time, i.e. the time setting for which the upper portion 12 remains pressed into engagement with the lower portion. The dwell time includes the time period during which heat is applied to the element means.
In FIG. 3, the melt zone means 35 represent the "melting" region where the material portion 37 (see FIGS. 3a and 5a) will melt or plasticize and be bonded together into a seal. At the region 33, the pressure and heat causes a split or tear bond, as shown at 34 in FIG. 4. The importance of proper selection of A, B, C, D and E for a given F, G and H can be appreciated here. If the recess depth B is too much, a tear bond 34 will not form because of lack of the proper crimping pressure at point 33. This setting for B may be utilized where a wide seal is desired over the entire region of the surface of the outer exposed portion of the heat element means 18a. If the recess depth is too little, there is too much drawdown of the material at the melt 37 (see FIGS. 3a and 5a), which degrades the material interface 39 (see FIG. 5b) and may give rise to a "zipper" effect to the bond.
The material 30 is a loose array of spunbonded fibers. The effect of the heat and clamping pressure causes a stress buildup at the interface between the melt and the material, degrading the molecular chain. This degradation is minimized through the design selection of A, B, C, D and E and correlating it to F, G and H as stated above. The design of the heat element means 18 and the recess means 24 takes advantage of changes in physical properties when the material 30 is heated and stretched over the heat element means. In heating and stretching, crosslinking and molecular lineup occurs. The molecular chain bending or slipping across the stretch direction is impeded. This increases the integrity and strength of the seam seal formed.
Fiberglass layer
The surface of the support plate means 16, the pressure plate 20 and recess means 24 may be provided with several layers of insulating material 38, such as teflon-impregnated fiberglass, teflon or phenolic laminates. The fiberglass layer 38 acts as an insulator. Additionally, use of coarse insulating material over the pressure plate acts as flow channels to stabilize the melt flow.
Recess and heat element means interchangeable in the several figures P In FIGS. 1-3, it can be appreciated that the recess means 24 may be provided in the lower portion 14 and the heat element means may be situated in the upper portion 12. The operation of the apparatus will be the same. The same applies to all the other figures.
Other embodiments
FIG. 5a shows another arrangement of the heat element means having crimping surface 43 and sloping sides 45. The sloping sides 45 provide the room for the melt zone means. The operation of FIG. 5 would be the same as in FIG. 3. FIG. 5b shows the region of the melt 37 on the material 30 and the melt-material interface at 39. The operation is the same as FIG. 3b.
Still another embodiment of the upper and lower portions 12 and 14 is shown in FIG. 6. Here the heat element means 18 comprises grooves 55. The recess means 24 is formed as 24a and 24b and a split zone 23. The split zone 23 and planar surface 53 are arranged such that crimping to form a tear bond, like 34 in FIG. 4, is avoided.
In operation, the configuration of FIG. 6 provides the double-bonds 36 shown in FIG. 8. This may be useful for the manufacture of some items where a reinforced or double seal is desired. The double seal may or may not be parallel. The provision of the split recess means 24 allow different pressures to be applied and obtain seals having different characteristics.
FIG. 6b shows another arrangement of the heat element means 18 with a channel 57 provided as the non-sealing region. The regions 59 are the sealing regions. The result is the double seal of FIG. 8. The configuration of FIG. 6b is particularly useful for parallel double seals.
FIG. 6c uses dual heat element means 18 and 19. With this configuration dual seals may be obtained by selecting A and B to avoid any crimping zone. The two heat element means 18 and 19 may be of different sizes, such as shown in FIG. 6d. In FIG. 6d, a crimp zone 33 may be provided in element 18 only. The result would be a double seam between the seal formed by heat element means 19 and one of the two melt zone means 35 of heat element means 18.
In FIGS. 2-6 it has been suggested that the heat element means 18 may comprise a spring-tensioned wire that is directly heated (for example, through electrical means). FIG. 7 shows the arrangement where the heat element means 18 is heated through heating means 58, such as electrical wire, imbedded within the lower portion 14. The heating means 58 may also be a port for passage of heating gases. Additionally, the recess means 24 is provided with heating means 54, which may be an electrically heated wire. The provision of the heating means 54 and 58 may be useful in some applications where greater heat is required within the confines of the heat element means and the recess means 24 from two directions. For example, with some materials because of their thickness or composition, when trying to effect a melt-through, the material closest to the heating element may degrade. This is avoided by using plural heating means. By heating from the top and the bottom, the melt can be better controlled. In FIG. 7 the heat of the heat element means 18 and the recess means 24a and 24b may be independently controlled through heat troughs such as shown in FIG. 2 for heat element means 18.
Interchangeability
As with FIGS. 1-3, it should be understood that the heat element means 18 of FIG. 8 may be utilized with the recess means of FIGS. 2-6; and similarly the recess means 24a and 24b of FIG. 7 may be utilized with any of the heat element means in FIGS. 2-6. This interchangeability feature includes other figures also.
Single edge joints
FIGS. 9a-9b shows formation of a single edge joint. The heat element means 18 has a single sloping face 45 to form the melt zone means 35. A stopper edge 62 is provided adjacent the heat element means to engage and position the edge 27 of the material layer 29 and 31. The heat element means 18 and recess means 24 operate in the same manner as described in FIGS. 1-8. Since only one edge joint is to be formed there is no provision in FIG. 9 for forming the tear 34 as shown in FIG. 4.
Flat ribbon element
FIGS. 1-9 have shown a circular cross-section for the heat element means. That should not be construed as a limitation of the present invention. For example, FIG. 10a shows a flat ribbon as the heat element means 18. Here the outer surface of the ribbon has rounded edges which form the melt zone means 35.
If the device of FIG. 10a is used only to form the seal 36, without forming a tear bond 34 (as in FIG. 4), then a crimping zone is not essential. FIG. 10b shows the bond 36.
It should also be noted that FIG. 10a does not show the recess means for receiving the heat element means. The upper portion 12 is shown as a flat member 25 that will compress, confine and hold the material sheets 29 and 31 into engagement with the heat element means. While the heat elememt means will heat and melt the materials in the seal region 37, the melt zone means serves to accumulate some of the material draw down as well as the region for transition from the seal to the material, i.e. the seal and seal-material interface. The edges 37 are rounded to prevent sharp edges and to assist in the material draw down into the melt zone means. It also provides a smooth transition from the seal heat face 19 to the melt zone means 35.
Thus, while in FIGS. 1-9 the recess means in the upper portion 11 has been shown distinctly, that is only one suggested method of obtaining the melt zone means and one that is particularly useful and applicable when the heat element means is circular.
FIG. 10c shows use of a flat ribbon to obtain dual seals. Here a recess means 24 is provided and a channel 64 is formed therein representing the region where sealing pressure is not applied on the material 30 and a seal is avoided. Seals are formed in the region 19a and 19b and melt zone 35. The result of the device of claim 10c is the dual seal of FIG. 8.
FIG. 10d shows another arrangement of the flat ribbon 19 to obtain dual seals. Here a channel 67 is formed in the ribbon-representing the region where pressure of the pressure plate means 20 is avoided. Seals are formed in the regions 19a and 19b and the melt zone means 35.
FIGS. 6-10 show dual seals. If a seal arrangement requiring more than two seals is desired, the number of split zones of the recess means may be increased, or the number of heat element means may be increased. For example, in FIGS. 6c-6d, three or four of the heat element means may be used, and in FIG. 10c a plurality of channels 64, and 67 in FIG. 10d, may be utilized.
Intermittent joints
For some purposes it is desirable to provide intermittent joints. For example FIG. 11a shows an intermittent edge joint and FIG. 11b shows an intermittent lap joint.
The intermittent joints can be obtained by the arrangement of the heat element means 18 as shown in FIGS. 12a and b. FIG. 12a shows the heat element means 18 having a certain length and a plurality of these are provided at spaced intervals. The recess means as required by the present invention will be arranged correspondingly. The heat element means may be a circular wire or a flat ribbon.
FIG. 11b shows the heat element 18 having indented portions at spaced intervals. The indented portions would be the nonbonding areas.
Instead of indenting the heat element means 18, the recess means 24 may be indented, as shown at FIG. 12c.
Lap joints
The bond of the lap joint may be made by increasing the dimension A in FIG. 3a, i.e. recessing the heat element means further into the support plate to reduce the draw down of the material during melt. The recess dimension B is reduced, i.e. the relief thereof is reduced correspondingly. The relief of the recess means allows for material slippage, and also applies a small amount of pressure on the heat element means and clamping pressure on the material.
Contoured seals
FIG. 13 shows the heat element means having a shape particularly useful where the bond to be formed is not linear. The heat element means is contoured, for example, to form the glove in FIG. 14. The heat element means as shown in FIG. 13 comprises a support portion 18a which is imbedded within the lower portion 14, and an elongated outer portion 18b having rounded edges. The recess means (not shown) for the heat element means 18b would have a substantially complementary shape. The provision of the large support portion 18a permits the heat element to be supported within the lower portion 14 while it is contoured to provide different shapes. The rounded edges of outer portion 18b allow for the seal to form around sharp bends.
With the configuration of the heat element means as in FIG. 14, two sheets of the material would be sealed with the seam formed in the shape of the contour. The finished product would be a glove. Similar configurations can be utilized for forming garments, envelopes, etc.
As shown in FIG. 14, the support plate 14 may be provided with expandable tips 70, urged outwardly by springs 72, at places where the heating element 18 rounds sharp curves in the contour. The reason for this arrangement is to prevent buckling of the heating element 18 as it expands linearly when heated. Alternatively, a portion 74 of the support plate 14 may be formed of a heat-resistant elastomeric material which is resiliently expandable in the direction of arrow 76.
Operation
With the above device, different types of thermoplastic materials can be bonded together. In some applications adhesive means may be utilized to augment the bond seal. In bonding the thermoplastic material at an edge the bond-material interface is critical for preserving the integrity of the seal bond. Stress at the bond-material is reduced through proper selection of the parameters A, B, C, D and E. The factors that must be considered may be listed as follows:
1. Clamping pressure applied on the material by the upper portion 12. This may be represented as P p.s.i.
2. Heat rise time, i.e. time required for the temperature of the heat element means to rise from its preset normal to a given temperature range. This may be represented as h t seconds.
3. Heat dwell time, i.e. the time period from the beginning of the heat rise time to the end of the cooling time. This may be represented as d seconds. Pressure is kept on during the entire period d.
4. Ambient humidity around the work station. This is represented as H percent. The material itself would be at room temperature and having humidity substantially the same as H.
5. Maximum permissible temperature of the heat element means during the heating state. This may be represented as t h degrees fahrenheit and the high of the range of part 2 above.
6. Minimum permissible temperature of the heat element means during the heating stage. This may be represented as t 1 degrees fahrenheit and the low of the range of part 2 above.
With the above factors and the device of the present invention, sheets of thermoplastic material can be joined at a seam with a strong airtight and waterproof seal (even if the material itself is not airtight and waterproof).
In operation, a length of heat element means having a desired cross-sectional configuration is provided. Its length is formed into the shape of the seal to be formed, i.e. linear, curved, shape of a glove, etc. A pressure plate means is provided having recess means, complementarily configured with the heat element means for receiving it. The material is kept at room temperature. The humidity of the material should preferably be substantially similar to the humidity at the work station. The humidity (H) of the work station is maintained between about 27 percent and about 52 percent.
The seam to be formed is positioned and clamped between the heat element means and the recess means. A pressure (P) of between about 20 p.s.i. and about 60 p.s.i. is applied by the pressure plate means. The heat element means is set at a "normal" temperature (T) of between about 58 degrees fahrenheit and about 72 degrees fahrenheit. The temperature of the heat element means is raised to a range between a high (t h ) of about 340 degrees fahrenheit and a low (t 1 ) of about 125 degrees fahrenheit. It can be appreciated that the setting of T determines how fast the heat element means can reach the (t h -t 1 ) range. The rise in temperature of heat is applied for a time period (h t ) of between about 0.38 seconds and about 5.51 seconds and a dwell time (d) of between about 0.53 seconds and about 14.01 seconds.
The material may be between about 6 mil and about 10 mil thick, and it may be coated or non-coated.
If the material is a Type 1 material fabricated from polyethylene, and made as a sheet about 10 mil thick, for example like Dupont's 1085, which is coated, the H may be set at about 28, P at about 40, T at about 68, t h at about 360, t 1 at about 150, h t at about 5.51 and d at about 11.45.
The material may comprise Type 2 material comprising spunbound olefin fibers, such as Dupont's 1444 Tyvek. Tyvek is about 6 mil thick. For this material H may be set at about 29, P at about 60, T at about 69, t h at about 265, t 1 at about 240, h t at about 4.48 and d at about 9.43. For this material a 0.032 diameter wire may be utilized as the heat element means, with dimension A shown in FIG. 3a being set at 0.01 inches.
A good seal can also be obtained with the above Tyvek 1444-type material by setting H at about 27, P at about 30, T at about 68, t h at about 165, t 1 at about 130, h t at about 2.00 and d at about 14.10. These settings utilize the same 0.32 diameter wire and 0.01 for A as above.
For Tyvek 1444-type material again, H may be set at about 27, P at about 30, T at about 68, t h at about 175, t 1 at about 140, h t at about 2.16 and d at about 12.13. These settings also use the 0.032 diameter wire and 0.01 for A.
For Type 3 material, for example, Dupont's Tyvek 1444A-type, H may be set at about 61, P at about 50, T at about 58, t h at about 200, t 1 at about 125, h t at about 1.08 and d at about 9.01. This uses the same 0.032 diameter wire, but with A being 0.008 inches.
For Type 4 material, for example, Dupont's Tyvek 1443T-type, H may be set at about 52, P at about 30, T at about 62, t h at about 250, t 1 at about 200, h t at about 0.61 and d at about 1.61. This uses the 0.032 diameter wire with A being 0.008 inches.
The material may comprise Type 5 material comprising polypropylene sheets, similar to Kimberly-Clark's Safeguard and having a thickness of about 10 mil. The Safeguard-type material comprises three layers pressed together. For this material, H may be set at about 30, P at about 15, T at about 69, t h at about 175, t 1 at about 125, h t at about 5.51, and d at about 11.45. Here, an 0.025 diameter wire may be used as the heat element means and A set at 0.008 inches.
For the Type 5 Kimberly-Clark Safeguard-type material, a good seal can also be obtained by setting H at about 50, P at about 20, T at about 68, t h at about 280, t 1 at about 200, h t at about 0.47, d at about 5.22. A 0.032 diameter wire may be used as the heat element means and A set at 0.01.
The material may comprise Type 6 material, comprising polypropylene sheet similar to Kimberly-Clark's Duraguard, and having 10 mil thickness. For this material, H may be set at about 32, P at about 20, T at about 63, t h at about 300, t 1 at about 200, h t at about 0.55, d at about 6.25. A 0.032 inch diameter wire may be utilized as the heat element means with A being 0.022 inches.
The material may comprise Type 7 material, comprising rayon and acrylic, similar to Chicopee's Duralace, and about 7 mil thick. For this material H may be set at about 55, P at about 40, T at about 62, t h at about 340, t 1 at about 220, h t at about 1.65 and d at about 6.62. A 0.032 inch diameter wire may be used with A set at 0.012 inches.
Additionally, for the Duralace-type material, a good seal can be obtained with H set at about 58, P at about 30, T at about 62, t h at about 220, t 1 at about 200, h t at about 0.38 and d at 0.53. A 0.016 diameter wire may be used as the heat element means with A equal to 0.003 inches.
The material may comprise Type 8 material comprising polypropylene sheets of single layers, similar to Crown Zellerbach's Celestra, of about 6 mil thickness. For this material H may be set at about 54, T at about 64, t h at about 220, t 1 at about 175, h t at about 1.15 and d at about 4.6. The heat element means may be 0.025 diameter wire with A set at 0.06.
Another type of polypropylene material may be Type 9 material, similar to Evolution #1221056, which is 10 mil thick. For this material H may be set at about 40, T at about 72, t h at about 180, t 1 at about 140, h t at about 0.88 and d at about 5.03. The heat element for this may be 0.03 diameter wire, with A set at 0.01 inches.
Still another polypropylene material may be Dupont's Typar 3301; whose thickness is about 12 mil. For this material, H may be set at about 42%, T at about 71°, t h at about 230°, t 1 at about 150°, h t at about 1.82 sec, and d at about 5.32 sec.
The above materials and their settings are illustrative of the manner of obtaining good thermobond seals. The following Table I provides an easy reference.
For other materials not noted above, the proper size and shape of the melt zone means may be selected and the parameters of H, P, T, t h , t 1 , h t and d adjusted within the broad range of the present invention and using the device of the present invention. It should be noted that the above method may be used also for fabrics that contain only a percentage of thermoplastic material.
Whereas the present invention has been described with a certain degree of particularity, it should be understood that other and further modifications may be made within the scope and spirit of this invention. The invention is not to be limited to the specific embodiment shown herein, but is to be limited only by the attached claims and each element thereof be entitled to the full range of equivalency.
It should also be noted that the invention is not limited to a specific brand-name material but is applicable generally to materials exemplified by the examples mentioned herein. | Method for thermobonding thermoplastic material. A support plate supports sheets of the thermoplastic material, and heat element means is provided adjacent thereto. Pressure plate means mates with the support plate and may include recess means for receiving the heat element means. Melt zone means are formed between the heat element means and the pressure plate means (or the recess means) when they are in mating relationship. The melt zone means serves to confine the melted thermoplastic means to form a good seal by relieving stress between the seal and the seal-material interface. The heat element means and recess means are manufactured as interchangeable dies in different sizes and shapes for different materials. The heat element means may be formed into different shapes, such as a glove for manufacturing gloves. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to Korean Patent Application No. 10-2008-0043039 filed on May 8, 2008, the entire contents of which applications is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a gas vapor control system, and more particularly to a gas vapor control system for reducing fuel consumption by controlling a gas vapor in an idle stop condition of a vehicle.
2. Description of Related Art
Generally, an idle stop-and-go system stops an engine in an idle state so as to reduce fuel consumption. Also, the engine is restarted without a key operation when the driving will of a driver is detected.
For example, when a vehicle speed is zero and a brake pedal is depressed for 3 seconds, the engine automatically stops, and when the brake pedal is not depressed and the accelerator pedal is depressed or a gear is shifted, the engine is restarted.
Further, a canister includes an absorbent material that can absorb gas vapor from a fuel tank, and when the gas vapor leaks out of a vehicle, exhaust gas regulations are not satisfied.
Accordingly, an engine control unit (ECU) causes the hydrocarbons that are captured in the canister to flow into the engine through a purge control valve.
On the other hand, in a vehicle that is equipped with the idle stop-and-go system, when the amount of gas vapor that is captured in the canister is greater than a predetermined value, the engine is restarted so as to combust the gas vapor in the idle stop condition.
Accordingly, the idle stop period is reduced such that there is problem in that fuel consumption increases. Particularly, when the gas vapor is fully charged in the canister, gas vapor that leaks out pollutes the environment.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY OF THE INVENTION
Various aspects of the present invention are directed to provide a gas vapor control system having advantages of increasing an idle stop period and decreasing fuel consumption by controlling gas vapor that is captured in a canister.
One aspect of the present invention is directed to a gas vapor control system that controls gas vapor that is generated in a fuel tank, the system including a canister in which gas vapor is captured, a throttle valve that is mounted in an intake passage through which air passes, a gas vapor passage connecting the fuel tank to a portion of the intake passage displaced before the throttle valve, wherein the canister is positioned at the gas vapor passage, a purge control valve that is mounted on the gas vapor passage, and/or a controller that stops an engine in an idle stop condition, and that closes the throttle valve and opens the purge control valve to flow the gas vapor of the canister into the intake passage when a canister load value (CL) is higher than a predetermined value.
The predetermined value (CL) of the canister load value may be approximately 0.9. The purge control valve may be displaced at the gas vapor passage between the canister and the portion of the intake passage displaced before the throttle valve. The controller may open the closed throttle valve after a first predetermined time period determined according to a variation amount of the canister load value (CL), and may restart the engine after closing the opened purge control valve. The variation amount of the canister load value (CL) may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor mounted on the fuel tank.
The canister load value (CL) may be lower than the predetermined value, the controller may sustain engine stop for a second predetermined time period determined according to the variation amount of the canister load value (CL). The variation amount of the canister load value may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor mounted on the fuel tank. The controller may close the purge control valve so as to not flow the gas vapor into the engine when the idle stop condition is satisfied and the canister load value is lower than the predetermined value.
The purge control valve may be displaced at the gas vapor passage between the canister and the portion of the intake passage displaced before the throttle valve. The controller opens the closed throttle valve after a first predetermined time period determined according to a variation amount of the canister load value (CL), and restarts the engine after closing the opened purge control valve. The variation amount of the canister load value (CL) may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor mounted on the fuel tank. When the canister load value (CL) is lower than the predetermined value, the controller may sustain engine stop for a second predetermined time period determined according to the variation amount of the canister load value (CL).
A passenger vehicle may include any of the engines described above.
A passenger vehicle may any of the gas vapor control systems described above. The purge control valve may be displaced at the gas vapor passage between the canister and the portion of the intake passage displaced before the throttle valve. The controller may open the closed throttle valve after a first predetermined time period determined according to a variation amount of the canister load value (CL), and restarts the engine after closing the opened purge control valve. The variation amount of the canister load value (CL) may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor mounted on the fuel tank. When the canister load value (CL) is lower than the predetermined value, the controller may sustain engine stop for a second predetermined time period determined according to the variation amount of the canister load value (CL).
Another aspect of the present invention is directed to a gas vapor control method that includes providing a canister in which the gas vapor may be captured, a throttle valve that is mounted in an intake passage through which air passes, a gas vapor passage connecting a fuel tank to a portion of the intake passage displaced before the throttle valve, wherein the canister may be positioned at the gas vapor passage, and a purge control valve that may be mounted on the gas vapor passage so as to control gas vapor and to flow the gas vapor into the intake passage, the method may further include detecting an engine stop in an idle stop condition of an engine, detecting a canister load value (CL), comparing the canister load value (CL) with a predetermined value, and/or closing the throttle valve and opening the purge control valve when the canister load value (CL) may be higher than the predetermined value.
The predetermined value may be approximately 0.9. The closed throttle valve may be opened after a first predetermined time period determined according to a variation amount of the canister load value (CL), and the engine may be restarted after closing the opened purge control valve. The variation amount of the canister load value may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor that may be mounted on the fuel tank. The engine stop may be sustained for a second predetermined time period determined according to a variation amount of the canister load value, when the canister load value (CL) may be lower than the predetermined value. The variation amount of the canister load value may be calculated through a pressure change of gas vapor that may be detected by a fuel pressure sensor that may be mounted on the fuel tank.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an exemplary gas vapor control system in accordance with the present invention.
FIG. 2 is a flow chart showing an exemplary gas vapor control method in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
FIG. 1 is a schematic diagram of a gas vapor control system according to an exemplary embodiment of the present invention.
Referring to FIG. 1 , an engine 10 includes an intake passage 15 , a throttle valve (ETC, 75 ), a throttle opening rate sensor 80 , a manifold pressure sensor 115 , an injector 110 , an exhaust passage 20 , a crankshaft 50 , a distributor 100 , a spark plug 105 , and oxygen sensors 155 and 160 .
Also, a fuel tank 120 , a fuel pressure sensor 125 , a fuel pump 135 , a canister 140 , a close valve 145 , and a purge control valve (PCV) 150 are disposed adjacent to the engine 10 . Further, a control portion or controller 180 that includes a program for controlling the above constituent elements is mounted.
The throttle valve 75 and the opening rate sensor 80 detecting a position of the throttle valve 75 are disposed in the intake passage 15 , and the manifold pressure sensor (DTP) 115 for sensing internal pressure is disposed downstream of the throttle valve 75 .
The injector 110 for injecting fuel is adjacent to the cylinder, and the oxygen sensors 155 and 160 for sensing oxygen of the exhaust gas are disposed in the exhaust passage 20 of the rear portion of the cylinder.
A fuel pump 135 is disposed at the fuel tank 120 so as to supply the injector 110 with fuel, and a fuel pressure sensor 125 is disposed at the fuel tank 120 so as to detect the inside pressure thereof.
A gas vapor passage 153 through which the gas vapor that is evaporated from the fuel of the fuel tank 120 passes is formed, and the gas vapor passage 153 is connected to the intake passage 15 . Further, the canister 140 is mounted substantially at the middle of the gas vapor passage 153 .
The purge control valve 150 for controlling the gas vapor that is supplied to the intake passage 15 is disposed in the rear end portion of the canister 140 .
The purge control valve 150 is controlled by the control portion 180 according to the gas vapor amount that is captured in the canister 140 , and supplies the intake passage 15 with the gas vapor.
The close valve 145 is closed so as to prevent the gas vapor from spreading to the atmosphere in a normal condition, and is opened in an emergency.
The canister load value (CL) is calculated based on a density of the gas vapor that passes through the purge control valve 150 and is included in the intake passage 15 in the present exemplary embodiment in which the idle stop-and-go system is applied.
That is, the control portion 180 calculates the canister load value (CL) based on a ratio of the fuel that is included in the gas vapor that flows into the intake passage 15 through the purge control valve 150 .
For example, the manifold pressure sensor (MAP, 115 ) senses an absolute pressure of the intake passage 15 , and the control portion 180 can more accurately calculate the canister load value (CL) based on the absolute pressure, volume, and temperature data. Also, the canister load value (CL) can be calculated based on an intake air amount, a gas vapor inflow amount by an opening of the purge control valve 150 , and a fuel/air ratio.
That is, if there is no gas vapor in the canister 140 , the canister load value becomes 0, and if the canister 140 is full of the gas vapor, the canister load value becomes 1.
When the canister load value (CL) is higher than a predetermined value (e.g. 0.9), the gas vapor may spread to the air. Accordingly, the engine may be restarted in the idle stop condition so as to prevent environmental pollution caused by the gas vapor spreading out the air.
According to an exemplary embodiment of the present invention, although the canister load value is higher than a predetermined value of 0.9 in an idle stop condition, the engine 10 is not restarted but the purge control valve 150 is opened such that the gas vapor that is captured in the canister 140 is supplied into the intake passage 15 . At this time, the throttle valve 75 is completely closed such that the gas vapor does not be spread out to the air. Accordingly, the idle stop period is extended, and thereby fuel consumption decreases.
Generally, the idle stop-and-go system is normally operated when the vehicle speed is lower than 3 km/h, the engine is in an idle condition, the gear is in a neutral position, and the clutch is released.
Further, the idle stop-and-go system is not operated when the operating switch is off, the SOC value of the battery is lower than a predetermined value, the safety belt is not worn, the door is open, the hydraulic pressure for braking is low, or one of the related sensors and switches breaks down.
The engine is restarted in the idle stop condition when the clutch is depressed in a normal condition, the vehicle speed is higher than 10 km/hr and the gear is neutral, or the hydraulic pressure for braking becomes lower.
In the idle stop-and-go system, a crank angle sensor is disposed so as to reduce a starting time when the engine is restarted, and a battery sensor is mounted so as to detect a charging condition and performance thereof. Further, the operating switch that is manipulated by the driver is prepared, and the display portion is disposed in the cluster so as to notify an operating condition of the idle stop-and-go system.
Also, a neutral switch for sensing a neutral condition of the gear and a position detecting switch for sensing a position of the clutch pedal are disposed.
An Absorbed Glass Mat (AGM) type of battery is applied so as to improve durability the battery. Further, it is desirable that a durable start motor and generator are used.
FIG. 2 is a flow chart showing a gas vapor control method according to an exemplary embodiment of the present invention.
Referring to FIG. 2 , in a first step S 101 , it is determined whether the idle stop condition is met or not. When the idle stop condition is determined, the engine is stopped in a second step S 102 , and the canister load value (CL) is detected according to the gas vapor amount that is captured in the canister 140 in third and fourth steps S 103 and S 104 .
The control portion 180 determines whether the canister load value (CL) is higher than a predetermined value (for example, 0.9) in a fifth step S 105 . When the canister load value (CL) is smaller than the predetermined value in the fifth step S 105 , the pressure change rate of gas vapor (ΔDTP 1 ) of the gas vapor is calculated by the control portion 180 from fuel pressure in the fuel tank 125 detected by the fuel pressure sensor 125 that is mounted on the fuel tank 125 in a sixth step S 106 . DTP 1 n and DTP 1 n− 1 illustrate fuel pressure at time n and time n−1, i.e., a pressure data sequentially detected by a time difference.
Thereafter, a first map data map 1 is selected according to the pressure change rate of gas vapor (ΔDTP 1 ) in the seventh step S 107 . Also, it is determined whether a predetermined time has elapsed or not according to the first map data map 1 in the eighth step S 108 . When the predetermined time passes, the steps S 8101 , 102 , S 103 , S 104 and S 105 are repeated.
Again, the control portion 180 determines that the canister load value (CL) is higher than the predetermined value in the fifth step S 105 , the throttle valve 75 is closed and the purge control valve 150 is opened in the ninth step S 109 such that the gas vapor flows into the intake passage 15 .
The pressure change rate of gas vapor (ΔDTP 2 ) of the gas vapor is calculated by the control portion 180 from fuel pressure in the fuel tank 125 detected by the fuel pressure sensor 125 that is mounted on the fuel tank 120 in a tenth step S 110 . Second map data map 2 is selected according to the pressure change rate of gas vapor (ΔDTP 2 ) in an eleventh step S 111 . Also, it is determined whether a predetermined time has elapsed or not according to the second map data map 2 in a twelfth step S 112 .
In the predetermined time, the throttle valve 75 is opened and the purge control valve 150 is closed in a thirteenth step S 113 , and the engine is restarted in a fourteenth step S 114 .
The intake passage 15 is almost full of the gas vapor in the eighth and the twelfth steps S 108 and S 112 , and the gas vapor amount that is captured in the canister 140 is also in a high range.
Also, the throttle valve 75 is electrically controlled through the control portion 180 and the throttle opening rate sensor 80 , and the purge control valve 150 is controlled to be opened/closed by the control portion.
For convenience in explanation and accurate definition in the appended claims, the terms “rear”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A gas vapor control system that controls gas vapor that is generated in a fuel tank may include a canister in which the gas vapor is captured, a throttle valve that is mounted in an intake passage through which air passes, a gas vapor passage connecting the fuel tank to a portion of the intake passage formed before the throttle valve, wherein the canister is positioned at the gas vapor passage, a purge control valve that is mounted on the gas vapor passage, and a control portion that stops an engine in an idle stop condition, and that closes the throttle valve and opens the purge control valve to flow the gas vapor into the intake passage when a canister load value (CL) is higher than a predetermined value. | 5 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to an eddy current damper, and a lithographic apparatus having an eddy current damper.
[0003] 2. Description of the Related Art
[0004] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
[0005] A lithographic apparatus contains a plurality of parts where one part is movable relative to another part. Examples of movable parts are a reticle or patterning device support, a wafer or substrate support, a balance mass, etc. Undesired movements of such parts may need to be damped. Such damping may be performed using at least an eddy current damper. However, the use of such an eddy current damper is not limited to lithographic apparatus, and may generally extend to apparatus having parts being movable relative to each other.
[0006] Eddy current dampers may use a set of permanent magnets or electromagnets as a source of magnetic field to be coupled to one part of an apparatus, and a body of an electrically conducting material to be coupled to another part of the apparatus, the one part and the other part being movable relative to each other, whereby eddy currents are generated in the electrically conducting body.
[0007] As a result of a relative movement of the magnets relative to the electrically conducting body, eddy currents are induced in the body. Consequently, an interaction of the eddy currents and the magnetic field of the permanent magnets generates forces between the magnets and the body that counteract the relative movement. This action is a damping or braking action that is proportional to electrical power produced by the eddy currents, and dissipated in the body. An eddy current damper is applicable both in apparatus with rotary relative movements and in apparatus with linear movements to generate a braking force, or to damp axial or radial vibrations.
[0008] The damping of an eddy current damper with a periodic array of magnetic poles is a function of many parameters. When focusing on a damping as a function of a relative movement frequency, it can be observed that the damping decreases significantly at frequencies above a cut-off frequency. The cut-off frequency is determined by a ratio of resistance over inductance of an imaginary coil created in the electrically conducting body of the eddy current damper.
[0009] Referring to M. P. Perry “Eddy currents damping due to a linear periodic array of magnetic poles”, IEEE Transactions on Magnetics, Vol. MAG-20, No. 1, January 1984, pages 149-155, if a high damping should be obtained at low frequencies, then a ratio of pole pitch of the magnets over a size of a gap between the magnets and the electrically conducting body should be high. However, the pole pitch is proportional to the coil inductance, and consequently an increase of the pole pitch results in an increase of the inductance and thus a decrease of the cut-off frequency. For this reason, although a high damping may be reached at low frequencies by choosing a large pole pitch, the damping will decrease at relatively low frequencies, and the resulting damper will have a low damping at high frequencies.
SUMMARY
[0010] It is desirable to provide an eddy current damper having an effective damping extending over a wide range of frequencies.
[0011] According to an embodiment of the invention, there is provided an eddy current damper, including an electrically conducting body having a face, and an array of magnets extending over the face, each magnet generating a magnetic field directed essentially transversely to the face, the magnet array generating oppositely directed magnetic fields each having a field width, wherein at least one of the magnetic fields generated by the magnets has a field width that is smaller than a field width of an adjacent magnetic field.
[0012] According to an embodiment of the invention, there is provided an eddy current damper, including an electrically conducting body having a face, and an array of magnets extending over the face, each magnet generating a magnetic field directed essentially transversely to the face, the magnet array generating oppositely directed magnetic fields each having a field width, wherein the conducting body has an opening having a width that is smaller than a field width of a corresponding magnetic field.
[0013] According to an embodiment of the invention, there is provided a lithographic apparatus including: an illumination system configured to condition a radiation beam; a patterning support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate support constructed to hold a substrate; and a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein at least one of the patterning support and the substrate support are coupled to an eddy current damper according to an embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:
[0015] FIG. 1 depicts a lithographic apparatus according to an embodiment of the invention;
[0016] FIG. 2 depicts a cross-section of a conventional eddy current damper;
[0017] FIG. 3 depicts another cross-section of a conventional eddy current damper;
[0018] FIG. 4 depicts a cross-section of an eddy current damper according to an embodiment of the present invention;
[0019] FIG. 5 depicts a cross-section of an eddy current damper according to a further embodiment of the present invention;
[0020] FIG. 6 depicts a cross-section of an eddy current damper according to an embodiment of the present invention;
[0021] FIG. 7 depicts a cross-section of an eddy current damper according to an embodiment of the present invention;
[0022] FIG. 8 depicts a cross-section of an eddy current damper according to a further embodiment of the present invention;
[0023] FIG. 9 depicts a perspective view of a conducting body of the eddy current damper of FIG. 8 ; and
[0024] FIG. 10 depicts a cross-section of an eddy current damper according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0025] FIG. 1 schematically depicts a lithographic apparatus according to one embodiment of the invention. The apparatus includes an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation or any other suitable radiation), a mask or patterning device support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioning device PM configured to accurately position the patterning device in accordance with certain parameters. The apparatus also includes a substrate table (e.g. a wafer table) WT or “substrate support” constructed to hold a substrate (e.g. a resist-coated wafer) W and connected to a second positioning device PW configured to accurately position the substrate in accordance with certain parameters. The apparatus further includes a projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. including one or more dies) of the substrate W.
[0026] The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation.
[0027] The mask support structure supports, i.e. bears the weight of, the patterning device. It holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The mask support structure can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The mask support structure may be a frame or a table, for example, which may be fixed or movable as required. The mask support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”
[0028] The term “patterning device” used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section so as to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.
[0029] The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam which is reflected by the mirror matrix.
[0030] The term “projection system” used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.
[0031] As here depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array of a type as referred to above, or employing a reflective mask).
[0032] The lithographic apparatus may be of a type having two (dual stage) or more substrate tables or “substrate supports” (and/or two or more mask tables or “mask supports”). In such “multiple stage” machines the additional tables or supports may be used in parallel, or preparatory steps may be carried out on one or more tables or supports while one or more other tables or supports are being used for exposure.
[0033] The lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the projection system and the substrate. An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques can be used to increase the numerical aperture of projection systems. The term “immersion” as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that a liquid is located between the projection system and the substrate during exposure.
[0034] Referring to FIG. 1 , the illuminator IL receives a radiation beam from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus and the radiation beam is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD including, for example, suitable directing mirrors and/or a beam expander. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.
[0035] The illuminator IL may include an adjuster AD configured to adjust the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may include various other components, such as an integrator IN and a condenser CO. The illuminator may be used to condition the radiation beam, to have a desired uniformity and intensity distribution in its cross-section.
[0036] The radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the mask support structure (e.g., mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioning device PW and position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g. so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioning device PM and another position sensor (which is not explicitly depicted in FIG. 1 ) can be used to accurately position the mask MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the mask table MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioning device PM. Similarly, movement of the substrate table WT or “substrate support” may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the mask table MT may be connected to a short-stroke actuator only, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M 1 , M 2 and substrate alignment marks P 1 , P 2 . Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.
[0037] Any of the mask table MT, the first positioning device PM, the substrate table WT and the second positioning device PW may be coupled to an eddy current damper according to the present invention to be described below with reference to FIGS. 2-10 .
[0038] The depicted apparatus could be used in at least one of the following modes:
[0039] 1. In step mode, the mask table MT or “mask support” and the substrate table WT or “substrate support” are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at once (i.e. a single static exposure). The substrate table WT or “substrate support” is then shifted in the X and/or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.
[0040] 2. In scan mode, the mask table MT or “mask support” and the substrate table WT or “substrate support” are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT or “substrate support” relative to the mask table MT or “mask support” may be determined by the (de-)magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion.
[0041] 3. In another mode, the mask table MT or “mask support” is kept essentially stationary holding a programmable patterning device, and the substrate table WT or “substrate support” is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated as required after each movement of the substrate table WT or “substrate support” or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.
[0042] Combinations and/or variations on the above-described modes of use or entirely different modes of use may also be employed.
[0043] FIG. 2 shows a conventional eddy current damper including a conducting body 1 , such as a plate, from an electrically conducting material, a first magnet array 2 of permanent magnets 2 a , 2 b mounted on a ferromagnetic body 3 , such as a plate, and a second magnet array 4 of permanent magnets 4 a , 4 b mounted on a ferromagnetic body 5 , such as a plate. In combination, the first magnet array 2 , the second magnet array 4 , and the ferromagnetic bodies 3 , 5 are also referred to as a field assembly. Each permanent magnet 2 a has the same direction of polarization, as indicated by an arrow without reference numeral. The same goes for the permanent magnets 2 b , for the permanent magnets 4 a , and for the permanent magnets 4 b . The permanent magnets 2 a and 2 b are arranged alternatingly, whereby also the direction of polarization of the permanent magnets alternates. The same goes for the permanent magnets 4 a and 4 b . The magnet arrays 2 and 4 create a magnetic field of which the lines are indicated in the Figure.
[0044] The first magnet array 2 , the second magnet array 4 , and the ferromagnetic bodies 3 , 5 are coupled to each other to form the field assembly as one part of the eddy current damper, whereas another part of the eddy current damper is formed by the conducting body 1 . Both parts are spaced from each other through a double gap 6 , such as an air gap, and movable relative to each other in either one of, or both directions as indicated by double arrow 7 . The movement causes the permanent magnets 2 a , 2 b , 4 a , 4 b to induce eddy currents in the conducting body 1 (as indicated at the left-hand part of the conducting body 1 ) to generate a force acting between the parts counteracting the movement. Thus, the movement is damped.
[0045] In general, the damping of an eddy current damper with a periodic array of magnetic poles, when analyzed as a function of a relative movement frequency, has a cut-off frequency above which the damping decreases significantly. In the following, an analysis of the parameters determining the cut-off frequency is made.
[0046] A damping appears in a force balance equation, which describes rigid body dynamics. The damping d is equal to
[0000]
d
=
-
F
v
(
1
)
[0000] where F is a force acting on a body, and v is a velocity of the body.
[0047] The damping of an eddy current damper can be written as a first order equation in a frequency domain
[0000]
d
=
-
k
2
R
coil
+
jω
L
coil
(
2
)
[0000] where k is a coefficient of an eddy current damper, R coil is a resistance of a coil, L coil is an inductance of the coil and ω is the electric angular frequency. The coil may include one or more windings of a conducting material, or may be defined by a shape of eddy currents induced in a body of conducting material, such as the conducting body 1 . Equation (2) shows that the damping is proportional to the square of k and inversely proportional to the impedance of the coil.
[0048] The cut-off frequency f cutoff of the damping is
[0000]
f
cutoff
=
-
R
coil
2
π
·
L
coil
.
(
3
)
[0049] In the following paragraphs, k, R coil and L coil are derived and dependencies become more transparent.
[0050] The coefficient of damper k is usually considered as a constant that is dependent only on parameters of magnetic circuit (dimensions, permanent flux density B r and coercive field intensity H c of permanent magnets, etc.).
[0051] In the simplest case, the damping d can be derived starting from a Lorentz force equation
[0000] {right arrow over (F)}=Q ( {right arrow over (E)}+{right arrow over (v)}×{right arrow over (B)}) (4)
Neglecting Coulomb's force FC
[0052] {right arrow over (F)} C =Q ( {right arrow over (E)} ) (5)
[0000] the force {right arrow over (F)} produced in the damper is
[0000] {right arrow over (F)}=Q ({right arrow over (v)}×{right arrow over (B)}) (6)
Knowing the motional electric field E m
[0053] E m ={right arrow over (v)}×{right arrow over (B)} gap (7)
[0000] the induced voltage V coil in the coil parts is
[0000]
V
coil
=
∫
l
E
m
l
=
k
·
v
(
8
)
Then, the total current flowing in the coil can be derived from a voltage equation
[0054]
0
=
i
coil
·
R
coil
+
L
coil
i
coil
t
+
V
coil
=
i
coil
·
R
coil
+
L
coil
i
coil
t
+
k
·
v
(
9
)
[0000] In the frequency domain, this yields:
[0000]
i
coil
=
k
·
v
(
R
coil
+
jω
L
coil
)
(
10
)
[0000] Finally, the damping of the system is found as:
[0000]
d
=
-
F
v
=
-
k
·
i
coil
v
=
-
k
2
R
coil
+
jω
L
coil
(
11
)
[0000] where:
F is a force created by the damper, B gap is a magnetic field in a gap of the damper, i coil is an induced eddy current, V coil is an induced voltage in coil parts under the permanent magnets, ω is an angular frequency of vibrations, R coil is a resistance of the coil, and v is a velocity of the coil.
From a mechanical point of view only the real part of equation (11) is the mechanical damping:
[0000]
d
=
Re
[
-
k
2
R
coil
+
jω
L
coil
]
(
12
)
[0000] As can be seen from equation (12), the mechanical damping has a significantly decreasing tendency for frequencies above a cut-off frequency. The frequency is proportional to a ratio of resistance over inductance.
[0062] The coil, considered in resistance and inductance estimations, is defined by induced eddy currents. This means that dimensions of the coil are coupled with the permanent magnet dimensions.
[0063] Resistance of the coil consists of four serial resistances, two end connections and two straight parts of the coil between the permanent magnets. Considering average dimensions of current path, the resistance of the coil can be expressed as two times the resistance of an end connection of the coil (parallel to the plane of the drawing) plus two times the resistance of a straight part of the coil (at right angles to the plane of the drawing):
[0000]
R
coil
=
2
·
ρ
τ
A
+
2
·
ρ
l
PM
A
(
13
)
[0000] where ρ is the specific resistance of the used conductor, τ is the pole pitch of the permanent magnets representing the average length of the end connections, l PM is the length of the magnets that is equal to an average length of the straight parts of the coil and A is the average cross-section of the coil. The cross-section of the coil may be approximated by
[0000] A=τ·h coil (14)
[0000] where:
h coil is a height of the coil.
[0065] An analytical equation of the inductance of the eddy current damper has a complex form. In order to show a main dependency of the coil inductance on the permanent magnet dimensions, the inductance can be calculated from an equation of two parallel wires in air:
[0000]
L
coil
=
μ
0
l
PM
π
ln
τ
h
(
15
)
[0000] where μ 0 is the magnetic permeability of air.
[0066] From equations (3), (13), (14) and (15) it appears that R coil decreases with increasing pole pitch τ, L coil increases with increasing pole pitch τ, and consequently the cut-off frequency f cutoff decreases with increasing pole pitch.
[0067] Returning to FIG. 2 , when a pole pitch of the permanent magnets 2 a , 2 b and the permanent magnets 4 a , 4 b is τ, the induced currents in the conducting body 1 form coils 8 with a periodicity of 2τ. Consequently, a self inductance L coil of the created coils is related to 2τ.
[0068] If a damping of the eddy current damper of FIG. 2 is to be increased by increasing the pole pitch of the permanent magnets, according to the prior art this may be done as illustrated by the embodiment of an eddy current damper of FIG. 3 .
[0069] According to FIG. 3 , an eddy current damper includes a conducting body 1 , such as a plate, from an electrically conducting material, a first magnet array 2 of permanent magnets 2 c , 2 d mounted on a ferromagnetic body 3 , such as a plate, and a second magnet array 4 of permanent magnets 4 c , 4 d mounted on a ferromagnetic body 5 , such as a plate. Each permanent magnet 2 c , 2 d , 4 c , 4 d has a direction of polarization, as indicated by an arrow without reference numeral. The magnet arrays 2 and 4 create a magnetic field of which the lines are indicated in the Figure.
[0070] For simplicity of discussion, in the embodiment of FIG. 3 a pole pitch of the permanent magnets of 2τ is selected. Consequently, coils 9 thus created in the conducting body 1 have a periodicity of 4τ. The self inductance L coil of the coils now is related to 4τ, and therefore larger than the self inductance of the coils with periodicity of 2τ of the eddy current damper of FIG. 2 . As a result, the eddy current damper of FIG. 3 has a higher damping at low frequencies and a lower damping at high frequencies than the eddy current damper of FIG. 2 .
[0071] According to FIG. 4 , an eddy current damper includes a conducting body 1 , such as a plate, from an electrically conducting material, a first magnet array 2 of permanent magnets 2 a , 2 b mounted on a ferromagnetic body 3 , such as a plate, and a magnet second array 4 of permanent magnets 4 a , 4 b mounted on a ferromagnetic body 5 , such as a plate. Each permanent magnet 2 a , 2 b , 4 a , 4 b has a direction of polarization, as indicated by an arrow without reference numeral. The magnet arrays 2 and 4 create a magnetic field of which the lines are indicated in the Figure.
[0072] When comparing FIG. 4 with FIG. 2 , it will be appreciated that the permanent magnets 2 a , 2 b in FIG. 4 have been arranged such that they form a combination of pole pitch τ and pole pitch 2τ, and consequently the magnet arrays 2 and 4 of FIG. 4 will force the induced eddy currents in the conducting body 1 to form coils 8 with a periodicity of τ and with a periodicity of 2τ.
[0073] An induced eddy current in the conducting body 1 between a permanent magnet 2 b and a permanent magnet 4 b at the left-hand or the right-hand side of FIG. 4 (these magnets are also referred to as “coil-forcing” magnets) is substantially half of an induced eddy current between the adjacent pairs of permanent magnets 2 a and 4 a . A first half of the induced eddy current between the pairs of permanent magnets 2 a , 4 a closes its current path between the permanent magnets 2 b , 4 b , and a second half of the induced eddy current between the pairs of permanent magnets 2 a , 4 a closes its current path between a next pair of permanent magnets 2 b , 4 b . Thus, in the embodiment of FIG. 4 , the current between pairs of permanent magnets is forced to split into two parts, and this will create periodically repeating coils of approximately the same dimensions as in the case depicted in FIG. 2 , as well as periodically repeating coils of approximately the same dimension as in the case depicted in FIG. 3 .
[0074] In this way, according to an embodiment of the invention, an eddy current damper being effective across a wide frequency range can be created. The eddy current damper of FIG. 4 will have the high damping of the eddy current damper of FIG. 3 at relatively low frequencies, and also a higher damping than the eddy current damper of FIG. 3 at relatively high frequencies. Thus, a settling time of device parts coupled to the eddy current damper may be reduced, and a performance of the device may increase in terms of higher throughput, higher acceleration levels and higher forces of drives. As an example, an eddy current damper designed to be operative in a frequency range of vibrations of 0-50 Hz may reach an approximately 30% higher damping over the whole frequency range during operation. Further, the magnetic flux in the eddy current damper according to an embodiment of the invention with coil forcing magnet is distributed differently from the magnetic flux in a conventional eddy current damper, which allows for the use of smaller ferromagnetic bodies, thereby reducing the total volume of the eddy current damper according to an embodiment of the invention. The same principle can also be used in linear motors/actuators with the same result: a reduction of the total volume of the ferromagnetic yoke.
[0075] From a manufacturing and a manufacturing cost point of view, it may be useful to assemble the eddy current damper of FIG. 4 from permanent magnets 2 a , 2 b , 4 a , 4 b which are identical. However, instead of using pairs of permanent magnets 2 a , 2 b , 4 a , 4 b , permanent magnets having the size of a pair of magnets may be used.
[0076] Referring to FIG. 5 , in an embodiment of the present invention coil-forcing magnets 2 e , 4 e , and 2 f , 4 f having a pole pitch τ may also be included in between periodically arranged permanent magnets 2 g , 2 h , 4 g , 4 h having a higher pole pitch 2τ, and need not be situated at a beginning or end of a periodic permanent magnet array such as shown in FIG. 4 .
[0077] Referring to FIG. 6 , in an embodiment of the present invention, coil-forcing magnets 2 e , 4 e , and 2 f , 4 f having a pole pitch τ may also be arranged next to each other in between periodically arranged permanent magnets 2 g , 2 h , 4 g , 4 h having a higher pole pitch 2τ.
[0078] Referring to FIG. 7 , in an embodiment of the present invention the effect of an increased damping at high frequencies can also be reached by having the conducting body 1 extending between only half of the permanent magnets 2 g , 4 g , and 2 h , 4 h at the right-hand side and the left-hand side, respectively, of the conducting body 1 in the Figure, whereas the permanent magnet arrays 2 and 4 include identical periodically arranged permanent magnets 2 g , 2 h , 4 g , 4 h , and no coil-forcing magnets. Seen from another perspective, the conducting body 1 includes a cut-out 10 at two opposite ends, each cut-out 10 having a width τ which is essentially half the width 2τ of a permanent magnet 2 g , 2 h , 4 g , 4 h.
[0079] As illustrated in FIGS. 8 and 9 , cut-outs 10 of the conducting body 1 having a width r which is essentially half the width 2τ of a permanent magnet 2 g , 2 h , 4 g , 4 h , may also be situated between permanent magnets 2 g , 4 g , 2 h , 4 h not situated at opposite ends of the conducting body 1 . In FIG. 9 , parts 1 a of the conducting body 1 form legs of coils of induced eddy currents, and parts 1 b of the conducting body 1 form end connections of coils of induced eddy currents.
[0080] As further illustrated in FIG. 10 , a cut-out 11 having a width 2τ (to be regarded as a pair of cut-outs 10 each having a width τ) may also be used whereby half of the cut-out 11 is situated between permanent magnets 2 g , 4 g , and the other half of the cut-out 11 is situated between permanent magnets 2 h , 4 h , each permanent magnet 2 g , 2 h , 4 g , 4 h having a width 2τ.
[0081] In FIGS. 2-8 and 10 , eddy current dampers have been shown including a conducting body 1 being movable between, and facing at both sides arrays of permanent magnets 2 , 4 . Other embodiments according to the invention may include a conducting body facing an array of permanent magnets at only one side thereof, and/or may include more than one conducting body and more than two permanent magnet arrays.
[0082] The magnet arrays, conducting body and ferromagnetic bodies may be configured to damp a linear movement or a rotary movement by selecting an appropriate design.
[0083] In FIGS. 2-6 , the present invention is illustrated in embodiments including coil-forcing magnets, whereas in FIGS. 7-10 , the present invention is illustrated in embodiments having a conducting body including one or more cut-outs. It will be appreciated that other embodiments according to the invention may include coil-forcing magnets as well as cut-outs.
[0084] Further it should be noted that other ratios between field widths/magnet widths of magnets than about 0.5 as illustrated in FIGS. 4-6 may be chosen, lying in the range between about 0 and 1. Similarly, other ratios between openings and magnet widths than about 0.5 as illustrated in FIGS. 7-10 may be chosen, lying in the range between about 0 and 1.
[0085] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion”, respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.
[0086] Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.
[0087] The terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. having a wavelength of or about 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm), as well as particle beams, such as ion beams or electron beams.
[0088] The term “lens”, where the context allows, may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.
[0089] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.
[0090] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.
[0091] The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as including (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. | An eddy current damper has an electrically conducting body having a face, and an array of magnets extending over the face of the conducting body. Each magnet generates a magnetic field directed essentially transversely to the face of the conducting body. The magnet array generates oppositely directed magnetic fields each having a field width. At least one of the magnetic fields generated by the magnets has a field width that is smaller than a field width of an adjacent magnetic field. The conducting body may have an opening having a width that is smaller than a field width of a corresponding magnetic field. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuing application of PCT Application No. PCT/JP01/07954 filed on Sep. 13, 2001, designating U.S.A. and now pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to laser processing methods and laser processing apparatus used for cutting objects to be processed such as semiconductor material substrates, piezoelectric material substrates, and glass substrates.
[0004] 2. Related Background Art
[0005] One of laser applications is cutting. A optical cutting process effected by laser is as follows: For embodiment, a part to be cut in an object to be processed such as a semiconductor wafer or glass substrate is irradiated with laser light having a wavelength absorbed by the object, so that melting upon heating proceeds due to the laser light absorption from the surface to rear face of the object to be processed at the part to be cut, whereby the object to be processed is cut. However, this method also melts surroundings of the region to become the cutting part in the surface of the object to be cut. Therefore, in the case where the object to be processed is a semiconductor wafer, semiconductor devices located near the above-mentioned region among those formed in the surface of the semiconductor wafer might melt. In the specification, “wafer shape” means a shape similar to a semiconductor wafer made of silicon of which thickness is about 100 μm, for example, a thin circular shape having a orientation flat therein.
[0006] Known as embodiments of methods which can prevent the surface of the object to be processed from melting are laser-based cutting methods disclosed in Japanese Patent Application Laid-Open No. 2000-219528 and Japanese Patent Application Laid-Open No. 2000-15467. In the cutting methods of these publications, the part to be cut in the object to be processed is heated with laser light, and then the object is cooled, so as to generate a thermal shock in the part to be cut in the object, whereby the object is cut.
[0007] When the thermal shock generated in the object to be processed is large in the cutting methods of the above-mentioned publications, unnecessary fractures such as those deviating from lines along which the object is intended to be cut or those extending to a part not irradiated with laser may occur. Therefore, these cutting methods cannot achieve precision cutting. When the object to be processed is a semiconductor wafer, a glass substrate formed with a liquid crystal display device, or a glass substrate formed with an electrode pattern in particular, semiconductor chips, liquid crystal display devices, or electrode patterns may be damaged due to the unnecessary fractures. Also, average input energy is so high in these cutting methods that the thermal damage imparted to the semiconductor chip and the like is large.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide laser processing methods and laser processing apparatus which generate no unnecessary fractures in the surface of an object to be processed and do not melt the surface.
[0009] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light with a light-converging point located therewithin, so as to form a modified region caused by multiphoton absorption within the object along a cutting line along which the object should be cut. If there is a certain start region in the part to be cut in the object to be processed, the object to be processed can be broken by a relatively small force so as to be cut. In the laser processing method in accordance with this aspect of the present invention, the object to be processed is broken along the line along which the object is intended to be cut using the modified region as the starting point, whereby the object can be cut. Hence, the object to be processed can be cut with a relatively small force, whereby the object can be cut without generating unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object.
[0010] The laser processing method in accordance with this aspect of the present invention locally generates multiphoton absorption within the object to be processed, thereby forming a modified region. Therefore, laser light is hardly absorbed by the surface of the object to be processed, whereby the surface of the object will not melt. Here, the light-converging point refers to the position where the laser light is converged. The line along which the object is intended to be cut may be a line actually drawn on the surface or inside of the object to be cut or a virtual line.
[0011] The laser processing method in accordance with an aspect the present invention comprises a step of irradiating an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region caused by multiphoton absorption within the object along a line along which the object is intended to be cut in the object.
[0012] The laser processing method in accordance with this aspect of the present invention irradiates an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point. Therefore, a phenomenon known as optical damage caused by multiphoton absorption occurs within the object to be processed. This optical damage induces thermal distortion within the object to be processed, thereby forming a crack region within the object to be processed. The crack region is an embodiment of the above-mentioned modified region, whereby the laser processing method in accordance with this aspect of the present invention enables laser processing without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object. An embodiment of the object to be processed in this laser processing method is a member including glass. Here, the peak power density refers to the electric field intensity of pulse laser light at the light-converging point.
[0013] The laser processing method in accordance with an aspect the present invention comprises a step of irradiating an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region including a molten processed region within the object along a line along which the object is intended to be cut in the object.
[0014] The laser processing method in accordance with this aspect of the present invention irradiates an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point. Therefore, the inside of the object to be processed is locally heated by multiphoton absorption. This heating forms a molten processed region within the object to be processed. The molten processed region is an embodiment of the above-mentioned modified region, whereby the laser processing method in accordance with this aspect of the present invention enables laser processing without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object. An embodiment of the object to be processed in this laser processing method is a member including a semiconductor material.
[0015] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 ns or less at the light-converging point, so as to form a modified region including a refractive index change region which is a region with a changed refractive index within the object along a line along which the object is intended to be cut in the object.
[0016] The laser processing method in accordance with this aspect of the present invention irradiates an object to be processed with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 ns or less at the light-converging point. When multiphoton absorption is generated within the object to be processed with a very short pulse width as in this aspect of the present invention, the energy caused by multiphoton absorption is not transformed into thermal energy, so that a permanent structural change such as ionic valence change, crystallization, or polarization orientation is induced within the object, whereby a refractive index change region is formed. This refractive index change region is an embodiment of the above-mentioned modified region, whereby the laser processing method in accordance with this aspect of the present invention enables laser processing without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object. An embodiment of the object to be processed in this laser processing method is a member including glass.
[0017] Modes employable in the foregoing laser processing methods in accordance with the present invention are as follows: Laser light emitted from a laser light source can include pulse laser light. The pulse laser light can concentrate the energy of laser spatially and temporally, whereby even a single laser light source allows the electric field intensity (peak power density) at the light-converging point of laser light to have such a magnitude that multiphoton absorption can occur.
[0018] Irradiating the object to be processed with a light-converging point located therewithin can encompass a case where laser light emitted from one laser light source is converged and then the object is irradiated with thus converged laser light with a light-converging point located therewithin, for embodiment. This converges laser light, thereby allowing the electric field intensity of laser light at the light-converging point to have such a magnitude that multiphoton absorption can occur.
[0019] Irradiating the object to be processed with a light-converging point located therewithin can encompass a case where the object to be processed is irradiated with respective laser light beams emitted from a plurality of laser light sources from directions different from each other with a light-converging point located therewithin. Since a plurality of laser light sources are used, this allows the electric field intensity of laser light at the light-converging point to have such a magnitude that multiphoton absorption can occur. Hence, even continuous wave laser light having an instantaneous power lower than that of pulse laser light can form a modified region. The respective laser light beams emitted from a plurality of laser light sources may enter the object to be processed from the surface thereof. A plurality of laser light sources may include a laser light source for emitting laser light entering the object to be processed from the surface thereof, and a laser light source for emitting laser light entering the object to be processed from the rear face thereof. A plurality of laser light sources may include a light source section in which laser light sources are arranged in an array along a line along which the object is intended to be cut. This can form a plurality of light-converging points along the line along which the object is intended to be cut at the same time, thus being able to improve the processing speed.
[0020] The modified region is formed by moving the object to be processed relative to the light-converging point of laser light located within the object. Here, the above-mentioned relative movement forms the modified region within the object to be processed along a line along which the object is intended to be cut on the surface of the object.
[0021] The method may further comprise a cutting step of cutting the object to be processed along the line along which the object is intended to be cut. When the object to be processed cannot be cut in the modified region forming step, the cutting step cuts the object. The cutting step breaks the object to be processed using the modified region as a starting point, thus being able to cut the object with a relatively small force. This can cut the object to be processed without generating unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object.
[0022] Embodiments of the object to be processed are members including glass, piezoelectric material, and semiconductor material. Another embodiment of the object to be processed is a member transparent to laser light emitted. This laser processing method is also applicable to an object to be processed having a surface formed with an electronic device or electrode pattern. The electronic device refers to a semiconductor device, a display device such as liquid crystal, a piezoelectric device, or the like.
[0023] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating a semiconductor material with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region within the semiconductor material along a line along which the object is intended to be cut in the semiconductor material. The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating a piezoelectric material with laser light with a light-converging point located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region within the piezoelectric material along a line along which the object is intended to be cut in the piezoelectric material. These methods enable laser cutting without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object to be processed for the same reason as that in the laser processing methods in accordance with the foregoing aspects of the present invention.
[0024] In the laser processing method in accordance with an aspect of the present invention, the object to be processed may have a surface formed with a plurality of circuit sections, while a light-converging point of laser light is located in the inside of the object to be processed facing a gap formed between adjacent circuit sections in the plurality of circuit sections. This can reliably cut the object to be processed at the position of the gap formed between adjacent circuit sections.
[0025] The laser processing method in accordance with an aspect of the present invention can converge laser light at an angle by which a plurality of circuit sections are not irradiated with the laser light. This can prevent the laser light from entering the circuit sections and protect the circuit sections against the laser light.
[0026] The laser processing method in accordance with an aspect the present invention comprises a step of irradiating a semiconductor material with laser light with a light-converging point located within the semiconductor material, so as to form a molten processed region only within the semiconductor material along a line along which the object is intended to be cut in the semiconductor material. The laser processing method in accordance with this aspect of the present invention enables laser processing without generating unnecessary fractures in the surface of the object to be processed and without melting the surface due to the same reasons as mentioned above. The molten processed region may be caused by multiphoton absorption or other reasons.
[0027] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light such that a light-converging point of laser light elliptically polarized with an ellipticity of other than 1 is located within the object to be processed while the major axis of an ellipse indicative of the elliptical polarization of the laser light extends along a line along which the object is intended to be cut, so as to form a modified region caused by multiphoton absorption along the line along which the object is intended to be cut within the object to be processed.
[0028] The laser processing method in accordance with this aspect of the present invention forms a modified region by irradiating the object to be processed with laser light such that the major axis of an ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed. The inventor has found that, when elliptically polarized laser light is used, the forming of a modified region is accelerated in the major axis direction of an ellipse indicative of the elliptical polarization (i.e., the direction in which the deviation in polarization is strong). Therefore, when a modified region is formed by irradiating the object to be processed with laser light such that the major axis direction of the ellipse indicative of the elliptical polarization extends along the line along which the object is intended to be cut in the object to be processed, the modified region extending along the line along which the object is intended to be cut can be formed efficiently. Therefore, the laser processing method in accordance with this aspect of the present invention can improve the processing speed of the object to be processed.
[0029] Also, the laser processing method in accordance with the present invention restrains the modified region from being formed except in the direction extending along the line along which the object is intended to be cut, thus making it possible to cut the object to be processed precisely along the line along which the object is intended to be cut.
[0030] Here, the ellipticity refers to half the length of the minor axis/half the length of major axis of the ellipse. As the ellipticity of laser light is smaller, the forming of modified region is accelerated in the direction extending along the line along which the object is intended to be cut but suppressed in the other directions. The ellipticity can be determined in view of the thickness, material, and the like of the object to be processed. Linear polarization is elliptical polarization with an ellipticity of zero.
[0031] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light such that a light-converging point of laser light elliptically polarized with an ellipticity of other than 1 is located within the object to be processed while the major axis of an ellipse indicative of the elliptical polarization of the laser light extends along a line along which the object is intended to be cut under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region including a crack region along the line along which the object is intended to be cut within the object to be processed.
[0032] The laser processing method in accordance with this aspect of the present invention irradiates the object to be processed with laser light such that the major axis of the ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed, thus making it possible to form the modified region efficiently and cut the object precisely along the line along which the object is intended to be cut as in the laser processing method in accordance with the above-mentioned aspect of the present invention.
[0033] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light such that a light-converging point of laser light elliptically polarized with an ellipticity of other than 1 is located within the object to be processed while the major axis of an ellipse indicative of the elliptical polarization of the laser light extends along the line along which the object is intended to be cut under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region including a molten processed region along the line along which the object is intended to be cut within the object to be processed.
[0034] The laser processing method in accordance with this aspect of the present invention irradiates the object to be processed with laser light such that the major axis of the ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed, thus making it possible to form the modified region efficiently and cut the object precisely along the line along which the object is intended to be cut as in the laser processing method in accordance with the above-mentioned aspect of the present invention.
[0035] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light such that a light-converging point of laser light elliptically polarized with an ellipticity of other than 1 is located within the object to be processed while the major axis of an ellipse indicative of the elliptical polarization of the laser light extends along a line along which the object is intended to be cut under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 ns or less at the light-converging point, so as to form a modified region including a refractive index change region which is a region with a changed refractive index within the object along a line along which the object is intended to be cut in the object.
[0036] The laser processing method in accordance with this aspect of the present invention irradiates the object to be processed with laser light such that the major axis of the ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed, thus making it possible to form the modified region efficiently and cut the object precisely along the line along which the object is intended to be cut as in the laser processing method in accordance with the above-mentioned aspect of the present invention.
[0037] Modes employable in the laser processing methods in accordance with the foregoing aspects of the present invention are as follows:
[0038] Laser light having elliptical polarization with an ellipticity of zero can be used. Linearly polarized light is obtained when the ellipticity is zero. Linearly polarized light can maximize the size of the modified region extending along the line along which the object is intended to be cut and minimize the sizes in the other directions. The ellipticity of elliptically polarized light can be adjusted by the angle of direction of a quarter-wave plate. When a quarter-wave plate is used, the ellipticity can be adjusted by changing the angle of direction alone.
[0039] After the step of forming the modified region, the object to be processed may be irradiated with laser light while the polarization of laser light is rotated by about 90° by a half-wave plate. Also, after the step of forming the modified region, the object to be processed may be irradiated with laser light while the object to be processed is rotated by about 90° about the thickness direction of the object to be processed. These can form another modified region extending in a direction along the surface of the object to be processed and intersecting the former modified region. Therefore, for embodiment, respective modified regions extending along lines along which the object is intended to be cut in X- and Y-axis directions can be formed efficiently.
[0040] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light such that a light-converging point of laser light elliptically polarized with an ellipticity of other than 1 is located within the object to be processed while the major axis of an ellipse indicative of the elliptical polarization of the laser light extends along a line along which the object is intended to be cut, so as to cut the object to be processed along the line along which the object is intended to be cut.
[0041] The laser processing method in accordance with this aspect of the present invention irradiates the object to be processed with laser light such that the major axis of the ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed. Therefore, the object to be processed can be cut along the line along which the object is intended to be cut. The laser processing method in accordance with this aspect of the present invention can cut the object to be processed by making the object absorb laser light so as to melt the object upon heating. Also, the laser processing method in accordance with this aspect of the present invention may generate multiphoton absorption by irradiating the object to be processed with laser light, thereby forming a modified region within the object, and cut the object while using the modified region as a starting point.
[0042] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; ellipticity adjusting means for making the pulse laser light emitted from the laser light source attain elliptical polarization with an ellipticity of other than 1; major axis adjusting means for making a major axis of an ellipse indicative of the elliptical polarization of the pulse laser light adjusted by the ellipticity adjusting means extend along a line along which the object is intended to be cut in an object to be processed; light-converging means for converging the pulse laser light adjusted by the major axis adjusting means such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging point within the object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along the line along which the object is intended to be cut.
[0043] The laser processing apparatus in accordance with this aspect of the present invention enables laser cutting without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object to be processed for the same reason as that in the laser processing methods in accordance with the above-mentioned aspects of the present invention. Also, it irradiates the object to be processed with laser light such that the major axis of the ellipse indicative of the elliptical polarization of laser light extends along the line along which the object is intended to be cut in the object to be processed, thus making it possible to form the modified region efficiently and cut the object precisely along the line along which the object is intended to be cut with the laser processing methods in accordance with the above-mentioned aspects of the present invention.
[0044] Modes employable in the laser processing apparatus in accordance with the present invention are as follows:
[0045] It may comprise 90° rotation adjusting means adapted to rotate the polarization of the pulse laser light adjusted by the ellipticity adjusting means by about 90°. Also, it may comprise rotating means for rotating a table for mounting the object to be processed by about 90° about a thickness direction of the object. These can make the major axis of the ellipse indicative of the elliptical polarization of pulse laser light extend along another line along which the object is intended to be cut which extends in a direction along a surface of the object to be processed while extending in a direction intersecting along the former line along which the object is intended to be cut. Therefore, for embodiment, respective modified regions extending along lines along which the object is intended to be cut in X- and Y-axis directions can be formed efficiently.
[0046] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less and linear polarization; linear polarization adjusting means for making the direction of linear polarization of the pulse laser light emitted from the laser light source align with a line along which the object is intended to be cut in an object to be processed; light-converging means for converging the pulse laser light adjusted by the linear polarization adjusting means such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging point within the object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along the line along which the object is intended to be cut.
[0047] The laser processing apparatus in accordance with this aspect of the present invention enables laser cutting without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object to be processed for the same reason as that in the laser processing methods in accordance with the above-mentioned aspects of the present invention. Also, as with the laser processing methods in accordance with the above-mentioned aspects of the present invention, the laser processing apparatus in accordance with this aspect of the present invention makes it possible to form the modified region efficiently and cut the object precisely along the line along which the object is intended to be cut.
[0048] (3) The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of the pulse laser light emitted from the laser light source according to an input of the magnitude of power of pulse laser light; light-converging means for converging the pulse laser light adjusted by the linear polarization adjusting means such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between the magnitude of power of pulse laser adjusted by the power adjusting means and the size of modified spot; size selecting means for choosing, according to an inputted magnitude of power of pulse laser light, a size of the modified spot formed at this magnitude of power from the correlation storing means; and size display means for displaying the size of modified spot chosen by the size selecting means.
[0049] The inventor has found that the modified spot can be controlled so as to become smaller and larger when the power of pulse laser light is made lower and higher, respectively. The modified spot is a modified part formed by one pulse of pulse laser light, whereas an assembly of modified spots forms a modified region. Control of the modified spot size affects cutting of the object to be processed. Namely, the accuracy in cutting the object to be processed along the line along which the object is intended to be cut and the flatness of the cross section deteriorate when the modified spot is too large. When the modified spot is too small for the object to be processed having a large thickness, on the other hand, the object is hard to cut. The laser processing apparatus in accordance with this aspect of the present invention can control the size of modified spot by adjusting the magnitude of power of pulse laser light. Therefore, it can cut the object to be processed precisely along the line along which the object is intended to be cut, and can obtain a flat cross section.
[0050] The laser processing apparatus in accordance with this aspect of the present invention also comprises correlation storing means having stored therein a correlation between the magnitude of power of pulse laser adjusted by the power adjusting means and the size of modified spot. According to an inputted magnitude of power of pulse laser light, the size of modified spot formed at this magnitude of power is chosen from the correlation storing means, and thus chosen size of modified spot is displayed. Therefore, the size of modified spot formed at the magnitude of power of pulse laser light fed into the laser processing apparatus can be seen before laser processing.
[0051] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; a light-converging lens for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; numerical aperture adjusting means for adjusting the size of numerical aperture of an optical system including the light-converging lens according to an inputted size of numerical aperture; means for locating the light-converging point of the pulse laser light converged by the light-converging lens within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between the size of numerical aperture adjusted by the power adjusting means and the size of modified spot; size selecting means for choosing, according to an inputted magnitude of power of pulse laser light, a size of the modified spot formed at this size of numerical aperture from the correlation storing means; and size display means for displaying the size of modified spot chosen by the size selecting means.
[0052] The inventor has found that the modified spot can be controlled so as to become smaller and larger when the numerical aperture of the optical system including the light-converging lens is made greater and smaller, respectively. Thus, the laser processing apparatus in accordance with this aspect of the present invention can control the size of modified spot by adjusting the size of numerical aperture of the optical system including the light-converging lens.
[0053] The laser processing apparatus in accordance with this aspect of the present invention also comprises correlation storing means having stored therein a correlation between the size of numerical aperture and the size of modified spot. According to an inputted size of numerical aperture, the size of modified spot formed at this magnitude of power is chosen from the correlation storing means, and thus chosen size of modified spot is displayed. Therefore, the size of modified spot formed at the size of numerical aperture fed into the laser processing apparatus can be seen before laser processing.
[0054] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; and lens selecting means including a plurality of light-converging lenses for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point, the lens selecting means being adapted to select among a plurality of light-converging lenses, a plurality of optical systems including the light-converging lenses having respective numerical apertures different from each other; means for locating the light-converging point of the pulse laser light converged by a light-converging lens chosen by the lens selecting means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between sizes of numerical apertures of a plurality of optical systems including the light-converging lenses and the size of modified spot; size selecting means for choosing, according to a size of numerical aperture of an optical system including a chosen light-converging lens, a size of the modified spot formed at this size of numerical aperture from the correlation storing means; and size display means for displaying the size of modified spot chosen by the size selecting means.
[0055] The laser processing apparatus in accordance with the present invention can control the size of modified spot. Also, the size of modified spot formed at the size of numerical aperture of the optical system including the chosen light-converging lens can be seen before laser processing.
[0056] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of pulse laser light emitted from the laser light source according to an inputted magnitude of power of pulse laser light; a light-converging lens for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; numerical aperture adjusting means for adjusting the size of numerical aperture of an optical system including the light-converging lens according to an inputted size of numerical aperture; means for locating the light-converging point of the pulse laser light converged by the light-converging lens within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between a set of the magnitude of power of pulse laser light adjusted by the power adjusting means and the size of numerical aperture adjusted by the numerical aperture adjusting means and the size of modified spot; size selecting means for choosing, according to an inputted magnitude of power of pulse laser light and an inputted size of numerical aperture, a size of the modified spot formed at thus inputted magnitude and size; and size display means for displaying the size of modified spot chosen by the size selecting means.
[0057] The laser processing apparatus in accordance with this aspect of the present invention can combine power adjustment with numerical aperture adjustment, thus being able to increase the number of kinds of controllable dimensions of modified spots. Also, for the same reason as that of the laser processing apparatus in accordance with the present invention, the size of modified spot can be seen before laser processing.
[0058] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of pulse laser light emitted from the laser light source according to an inputted magnitude of power of pulse laser light; lens selecting means including a plurality of light-converging lenses for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point, the lens selecting means being adapted to select among a plurality of light-converging lenses, a plurality of optical systems including the light-converging lenses having respective numerical apertures different from each other; means for locating the light-converging point of the pulse laser light converged by a light-converging lens chosen by the lens selecting means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored there in a correlation between a set of the magnitude of power of pulse laser light adjusted by the power adjusting means and sizes of numerical apertures of a plurality of optical systems including the light-converging lenses and the size of modified spot; size selecting means for choosing, according to an inputted magnitude of power of pulse laser light and an inputted size of numerical aperture, a size of the modified spot formed at thus inputted magnitude and size; and size display means for displaying the size of modified spot chosen by the size selecting means.
[0059] For the same reason as that of the laser processing apparatus in accordance with the above-mentioned aspect of the present invention, the laser processing apparatus in accordance with this aspect of the present invention can increase the number of kinds of controllable dimensions of modified spots and can see the size of modified spots before laser processing.
[0060] The laser processing apparatus explained in the foregoing may comprise image preparing means for preparing an image of modified spot having the size selected by the size selecting means, and image display means for displaying the image prepared by the image preparing means. This allows the formed modified spot to be grasped visually before laser processing.
[0061] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of pulse laser light emitted from the laser light source; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between the magnitude of power of pulse laser light adjusted by the power adjusting means and the size of modified spot; power selecting means for choosing, according to an inputted size of modified spot, a magnitude of power of pulse laser light adapted to form this size from the correlation storing means; the power adjusting means adjusting the magnitude of power of pulse laser light emitted from the laser light source such that the magnitude of power chosen by the power selecting means is attained.
[0062] The laser processing apparatus in accordance with this aspect of the present invention comprises correlation storing means having stored therein the magnitude of power of pulse laser light and the size of modified spot. According to an inputted size of the modified spot, the magnitude of power of pulse laser light adapted to form this size is chosen from the correlation storing means. The power adjusting means adjusts the magnitude of power of pulse laser light emitted from the laser light source so as to make it become the magnitude of power chosen by the power selecting means. Therefore, a modified spot having a desirable size can be formed.
[0063] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; a light-converging lens for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; numerical aperture adjusting means for adjusting the size of numerical aperture of an optical system including the light-converging lens according to an inputted size of numerical aperture; means for locating the light-converging point of the pulse laser light converged by the light-converging lens within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between the size of numerical aperture adjusted by the numerical aperture adjusting means and the size of modified spot; and numerical aperture selecting means for choosing, according to an inputted size of modified spot, the size of numerical aperture adapted to form thus inputted size; the numerical aperture adjusting means adjusting the size of numerical aperture of the optical system including the light-converging lens such that the size of numerical aperture chosen by the numerical aperture selecting means is attained.
[0064] The laser processing apparatus in accordance with this aspect of the present invention comprises correlation storing means having stored therein the size of numerical aperture and the size of modified spot. According to an inputted size of modified spot, the size of numerical aperture adapted to form thus inputted size is chosen from the correlation storing means. The numerical aperture adjusting means adjusts the size of numerical aperture of the optical system including the light-converging lens such that the size of numerical aperture chosen by the numerical aperture selecting means is attained. Therefore, modified spots having a desirable size can be formed.
[0065] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; lens selecting means including a plurality of light-converging lenses for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point, the lens selecting means being adapted to select among a plurality of light-converging lenses, a plurality of optical systems including the light-converging lenses having respective numerical apertures different from each other; means for locating the light-converging point of the pulse laser light converged by a light-converging lens chosen by the lens selecting means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between sizes of numerical apertures of a plurality of light-converging lenses and the size of modified spot; and numerical aperture selecting means for choosing, according to an inputted size of modified spot, a size of numerical aperture adapted to form thus inputted size; the lens selecting means selecting among a plurality of light-converging lenses such that the size of numerical aperture chosen by the numerical aperture selecting means is attained.
[0066] According to an inputted size of modified spot, the laser processing apparatus in accordance with this aspect of the present invention chooses the size of numerical aperture adapted to form thus inputted size. The lens selecting means selects among a plurality of light-converging lenses such that the size of numerical aperture chosen by the numerical aperture selecting means is attained. Therefore, modified spots having a desirable spots can be formed.
[0067] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of pulse laser light emitted from the laser light source; a light-converging lens for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; numerical aperture adjusting means for adjusting the size of numerical aperture of an optical system including the light-converging lens; means for locating the light-converging point of the pulse laser light converged by the light-converging lens within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between a set of the magnitude of power of pulse laser light adjusted by the power adjusting means and the size of numerical aperture adjusted by the numerical aperture adjusting means and the size of modified spot; and set selecting means for choosing, according to an inputted size of modified spot, a set of the magnitude of power and size of numerical aperture adapted to form this size; the power adjusting means and numerical aperture adjusting means adjusting the magnitude of power of pulse laser light emitted from the laser light source and the size of numerical aperture of the optical system including the light-converging lens such that the magnitude of power and size of numerical aperture chosen by the set selecting means are attained.
[0068] According to an inputted size of modified spot, the laser processing apparatus in accordance with this aspect of the present invention chooses a combination of the magnitude of power and size of numerical aperture adapted to form thus inputted size from the correlation storing means. Then, it adjusts the magnitude of power of pulse laser light and the size of numerical aperture of the optical system including the light-converging lens so as to attain the chosen magnitude of power and size of numerical aperture. Therefore, modified spots having a desirable size can be formed. Also, since the magnitude of power and the size of numerical aperture are combined together, the number of kinds of controllable dimensions of modified spots can be increased.
[0069] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; power adjusting means for adjusting the magnitude of power of pulse laser light emitted from the laser light source; lens selecting means including a plurality of light-converging lenses for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point, the lens selecting means being adapted to select among a plurality of light-converging lenses, a plurality of optical systems including the light-converging lenses having respective numerical apertures different from each other; means for locating the light-converging point of the pulse laser light converged by a light-converging lens chosen by the lens selecting means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; the laser processing apparatus further comprising correlation storing means having stored therein a correlation between a set of the magnitude of power of pulse laser light adjusted by the power adjusting means and sizes of numerical apertures of a plurality of optical systems including the light-converging lenses and the size of modified spot; and set selecting means for choosing, according to an inputted size of modified spot, a set of the magnitude of power and size of numerical aperture adapted to form thus inputted size from the correlation storing means; the power adjusting means and lens selecting means adjusting the magnitude of power of pulse laser light emitted from the laser light source and selecting among a plurality of light-converging lenses so as to attain the power and size of numerical aperture chosen by the set selecting means.
[0070] According to an inputted size of modified spot, the laser processing apparatus in accordance with this aspect of the present invention chooses a combination of the magnitude of power and size of numerical aperture adapted to form thus inputted size from the correlation storing means. It adjusts the magnitude of power of pulse laser light emitted from the laser light source and selects among a plurality of light-converging lenses so as to attain the chosen magnitude of power and size of numerical aperture, respectively. Therefore, modified spots having a desirable size can be formed. Also, since the magnitude of power and the size of numerical aperture are combined together, the number of kinds of controllable dimensions of modified spots can be increased.
[0071] The laser processing apparatus in accordance with this aspect of the present invention may further comprise display means for displaying the magnitude of power chosen by the power selecting means, display means for displaying the size of numerical aperture chosen by the numerical aperture selecting means, and display means for displaying the magnitude of power and size of numerical aperture of the set chosen by the set selecting means. This makes it possible to see the power and numerical aperture when the laser processing apparatus operates according to an inputted size of modified spot.
[0072] The laser processing apparatus can form a plurality of modified spots along a line along which the object is intended to be cut within the object to be processed. These modified spots define a modified region. The modified region includes at least one of a crack region where a crack is generated within the object to be processed, a molten processed region which is melted within the object to be processed, and a refractive index change region where refractive index is changed within the object to be processed.
[0073] An embodiment of modes of power adjusting means is one including at least one of an ND filter and a polarization filter. In another mode, the laser light source includes a pumping laser whereas the laser processing apparatus comprises driving current controlling means for controlling the driving current of the pumping laser. These can adjust the magnitude of power of pulse laser light. An embodiment of modes of numerical aperture adjusting means includes at least one of a beam expander and an iris diaphragm.
[0074] The laser processing method in accordance with an aspect of the present invention comprises a first step of irradiating an object to be processed with pulse laser light while locating a light-converging point of the pulse laser light within the object, so as to form a first modified region caused by multiphoton absorption within the object along a first line along which the object is intended to be cut in the object; and a second step of irradiating the object with pulse laser light while making the pulse laser light attain a power higher or lower than that in the first step and locating the light-converging point of the pulse laser light within the object, so as to form a second modified region caused by multiphoton absorption within the object along a second line along which the object is intended to be cut in the object.
[0075] The laser processing method in accordance with an aspect of the present invention comprises a first step of irradiating an object to be processed with pulse laser light while locating a light-converging point of the pulse laser light within the object, so as to form a first modified region caused by multiphoton absorption within the object along a first line along which the object is intended to be cut in the object; and a second step of irradiating the object with pulse laser light while making an optical system including a light-converging lens for converging the pulse laser light attain a numerical aperture greater or smaller than that in the first step and locating the light-converging point of the pulse laser light within the object, so as to form a second modified region caused by multiphoton absorption within the object along a second line along which the object is intended to be cut in the object.
[0076] When respective directions which are easy to cut and hard to cut exist due to the crystal orientation, for embodiment, the laser processing methods in accordance with these aspects of the present invention decreases the size of modified spot constituting a modified region formed in the easy-to-cut direction and increases the size of modified spot constituting another modified region formed in the hard-to-cut direction. This can attain a flat cross section in the easy-to-cut direction and enables cutting in the hard-to-cut direction as well.
[0077] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; frequency adjusting means for adjusting the magnitude of a repetition frequency of the pulse laser light emitted from the laser light source according to an inputted magnitude of frequency; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising distance calculating means for calculating a distance between modified spots adjacent each other according to an inputted magnitude of frequency; and distance display means for displaying the distance calculated by the distance calculating means.
[0078] The inventor has found that, when the light-converging point of pulse laser light has a fixed relative moving speed, the distance between a modified part (referred to as modified spot) formed by one pulse of pulse laser light and a modified spot formed by the next one pulse of laser light can be made greater by lowering the repetition frequency. It has been found that, by contrast, the distance can be made shorter by increasing the repetition frequency of pulse laser light. In the present specification, this distance is expressed as the distance or pitch between adjacent modified spots.
[0079] Therefore, the distance between the adjacent modified spots can be controlled by carrying out adjustment for increasing or decreasing the repetition frequency of pulse laser light. Changing the distance according to the kind, thickness, and the like of the object to be processed enables cutting in conformity to the object to be processed. Forming a plurality of modified spots along a line along which the object is intended to be cut within the object to be processed defines a modified region.
[0080] The laser processing apparatus in accordance with this aspect of the present invention calculates the distance between adjacent modified spots according to the inputted magnitude of frequency, and displays thus calculated distance. Therefore, with respect to modified spots formed according to the magnitude of frequency fed into the laser processing apparatus, the distance between adjacent spots can be seen before laser processing.
[0081] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; and speed adjusting means for adjusting the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means according to an inputted magnitude of speed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising distance calculating means for calculating a distance between modified spots adjacent each other according to an inputted magnitude of speed; and distance display means for displaying the distance calculated by the distance calculating means.
[0082] The inventor has found that, when the light-converging point of pulse laser light has a fixed relative moving speed, the distance between adjacent modified spots can be made shorter and longer by decreasing and increasing the relative moving speed of the light-converging point of pulse laser light, respectively. Therefore, the distance between adjacent modified spots can be controlled by increasing or decreasing the relative moving speed of the light-converging point of pulse laser light. As a consequence, a cutting process suitable for an object to be processed is possible by changing the distance according to the kind, thickness, and the like of the object to be processed. The relative movement of the light-converging point of pulse laser light may be achieved by moving the object to be processed while fixing the light-converging point of pulse laser light, by moving the light-converging point of pulse laser light while fixing the object to be processed, or by moving both.
[0083] The laser processing apparatus in accordance with this aspect of the present invention calculates the distance between adjacent modified spots according to the inputted magnitude of speed, and displays thus calculated distance. Therefore, with respect to modified spots formed according to the magnitude of speed fed into the laser processing apparatus, the distance between adjacent spots can be seen before laser processing.
[0084] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; frequency adjusting means for adjusting the magnitude of a repetition frequency of the pulse laser light emitted from the laser light source according to an inputted magnitude of frequency; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; and speed adjusting means for adjusting the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means according to an inputted magnitude of speed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising distance calculating means for calculating a distance between modified spots adjacent each other according to inputted magnitudes of frequency and speed; and distance display means for displaying the distance calculated by the distance calculating means.
[0085] The laser processing apparatus in accordance with this aspect of the present invention adjusts both the magnitude of a repetition frequency of pulse laser light and the magnitude of relative moving speed of the light-converging point, thereby being able to control the distance between adjacent modified spots. Combining these adjustments makes it possible to increase the number of kinds of controllable dimensions concerning the distance. Also, the laser processing apparatus in accordance with this aspect of the present invention allows the distance between adjacent modified spots to be seen before laser processing.
[0086] These laser processing apparatus may further comprise size storing means having stored therein the size of a modified spot formed by the laser processing apparatus; image preparing means for preparing an image of a plurality of modified spots formed along a line along which the object is intended to be cut according to the size stored in the sizes to ring means and the distance calculated by the distance calculating means; and image display means for displaying the image prepared by the image preparing means. This allows a plurality of modified spots, i.e., modified region, to be grasped visually before laser processing.
[0087] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; frequency adjusting means for adjusting the magnitude of a repetition frequency of the pulse laser light emitted from the laser light source according to an inputted magnitude of frequency; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising frequency calculating means for calculating, according to an inputted magnitude of distance between modified spots adjacent each other, the magnitude of repetition frequency of the pulse laser light emitted from the laser light source so as to attain thus inputted magnitude of distance between the modified spots adjacent each other; the frequency adjusting means adjusting the magnitude of repetition frequency of the pulse laser light emitted from the laser light source such that the magnitude of frequency calculated by the frequency calculating means is attained.
[0088] According to an inputted magnitude of distance between adjacent modified spots, the laser processing apparatus in accordance with this aspect of the present invention calculates the magnitude of a repetition frequency of the pulse laser light emitted from the laser light source such that this magnitude of distance is attained between the adjacent modified spots. The frequency adjusting means adjusts the magnitude of repetition frequency of the pulse laser light emitted from the laser light source such that the magnitude of frequency calculated by the frequency calculating means is attained. Therefore, a desirable magnitude of distance can be attained between adjacent modified spots.
[0089] The laser processing apparatus in accordance with this aspect of the present invention may further comprise frequency display means for displaying the magnitude of frequency calculated by the frequency calculating means. When operating the laser processing apparatus according to the inputted magnitude of distance between adjacent modified spots, this allows the frequency to be seen before laser processing.
[0090] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; and speed adjusting means for adjusting the magnitude of relative moving speed of the light-converging point caused by the moving means; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising speed calculating means for calculating, according to an inputted magnitude of distance between modified spots adjacent each other, the magnitude of relative moving speed of the pulse laser light so as to attain thus inputted magnitude of distance between the modified spots adjacent each other; the speed adjusting means adjusting the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means such that the magnitude of relative moving speed calculated by the speed calculating means is attained.
[0091] According to an inputted magnitude of distance between adjacent modified spots, the laser processing apparatus in accordance with this aspect of the present invention calculates the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means. The speed adjusting means adjusts the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means such that the magnitude of relative moving speed calculated by the frequency calculating means is attained. Therefore, a desirable magnitude of distance can be attained between adjacent modified spots.
[0092] The laser processing apparatus in accordance with this aspect of the present invention may further comprise speed display means for displaying the magnitude of relative moving speed calculated by the speed calculating means. When operating the laser processing apparatus according to the inputted magnitude of distance between adjacent modified spots, this allows the relative moving speed to be seen before laser processing.
[0093] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; frequency adjusting means for adjusting the magnitude of a repetition frequency of the pulse laser light emitted from the laser light source; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light converged by the light-converging means within an object to be processed; moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed; and speed adjusting means for adjusting the magnitude of relative moving speed of the light-converging point caused by the moving means; wherein one modified spot is formed within the object to be processed by irradiating the object to be processed with one pulse of pulse laser light while locating the light-converging point within the object; and wherein a plurality of modified spots are formed along the line along which the object is intended to be cut within the object to be processed by irradiating the object to be processed with a plurality of pulses of pulse laser light while locating the light-converging point within the object and relatively moving the light-converging point along the line along which the object is intended to be cut; the laser processing apparatus further comprising combination calculating means for calculating, according to an inputted magnitude of distance between modified spots adjacent each other, a combination of the magnitude of repetition frequency of the pulse laser light emitted from the laser light source and the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means so as to attain thus inputted magnitude of distance between the modified spots adjacent each other; the frequency adjusting means adjusting the magnitude of repetition frequency of the pulse laser light emitted from the laser light source such that the magnitude of frequency calculated by the combination calculating means is attained; the speed adjusting means adjusting the magnitude of relative moving speed of the light-converging point of pulse laser light caused by the moving means such that the magnitude of relative moving speed calculated by the combination calculating means is attained.
[0094] The laser processing apparatus in accordance with this aspect of the present invention calculates, according to an inputted magnitude of distance between adjacent modified spots, a combination of the magnitude of repetition frequency of pulse laser light and the relative moving speed of the light-converging point of pulse laser light such that thus inputted magnitude of distance is attained between the adjacent modified spots. The frequency adjusting means and speed adjusting means adjust the magnitude of repetition frequency and the magnitude of relative moving speed of the light-converging point of pulse laser light so as to attain the values of calculated combination. Therefore, a desirable magnitude of distance can be attained between adjacent modified spots.
[0095] The laser processing apparatus in accordance with the present invention may comprise display means for displaying the magnitude of frequency and magnitude of relative moving speed calculated by the combination calculating means. When operating the laser processing apparatus according to the inputted magnitude of distance between adjacent modified spots, this allows the combination of frequency and relative moving speed to be seen before laser processing.
[0096] The laser processing apparatus in accordance with all the foregoing aspects of the present invention can form a plurality of modified spots along a line along which the object is intended to be cut within the object to be processed. These modified spots define a modified region. The modified region includes at least one of a crack region where a crack is generated within the object to be processed, a molten processed region which is melted within the object to be processed, and a refractive index change region where refractive index is changed within the object to be processed.
[0097] The laser processing apparatus in accordance with all the foregoing aspects of the present invention can adjust the distance between adjacent modified spots, thereby being able to form a modified region continuously or discontinuously along a line along which the object is intended to be cut. Forming the modified region continuously makes it easier to cut the object to be processed while using the modified region as compared with the case where it is not formed continuously. When the modified region is formed discontinuously, the modified region is discontinuous along the line along which the object is intended to be cut, whereby the part of the line along which the object is intended to be cut keeps a strength to a certain extent.
[0098] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light while locating a light-converging point of laser light within the object to be processed, so as to form a modified region caused by multiphoton absorption within the object along a line along which the object is intended to be cut in the object, and changing the position of the light-converging point of laser light in the direction of incidence of the laser light irradiating the object to be processed with respect to the object to be processed, so as to form a plurality of modified regions aligning with each other along the direction of incidence.
[0099] By changing the position of the light-converging point of laser light irradiating the object to be processed in the direction of incidence with respect to the object to be processed, the laser processing method in accordance with this aspect of the present invention forms a plurality of modified regions aligning with each other along the direction of incidence. This can increase the number of positions to become starting points when cutting the object to be processed. Therefore, the object to be processed can be cut even in the case where the object to be processed has a relatively large thickness and the like. Embodiments of the direction of incidence include the thickness direction of the object to be processed and directions orthogonal to the thickness direction.
[0100] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light while locating a light-converging point of laser light within the object to be processed, so as to form a modified region within the object along a line along which the object is intended to be cut in the object, and changing the position of the light-converging point of laser light in the direction of incidence of the laser light irradiating the object to be processed with respect to the object to be processed, so as to form a plurality of modified regions aligning with each other along the direction of incidence. The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light while locating a light-converging point of laser light within the object to be processed under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, so as to form a modified region within the object to be processed along a line along which the object is intended to be cut in the object, and changing the position of the light-converging point of laser light in the direction of incidence of the laser light irradiating the object to be processed with respect to the object to be processed, so as to form a plurality of modified regions aligning with each other along the direction of incidence.
[0101] For the same reason as that in the laser processing methods in accordance with the foregoing aspects of the present invention, the laser processing methods in accordance with these aspects of the present invention enable laser cutting without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object to be processed, and can increase the number of positions to become starting points when cutting the object to be processed. The modified region may be caused by multiphoton absorption or other reasons.
[0102] The laser processing methods in accordance with these aspects of the present invention include the following modes:
[0103] A plurality of modified regions may be formed successively from the side farther from an entrance face of the object to be processed on which laser light irradiating the object to be processed is incident. This can form a plurality of modified regions while in a state where no modified region exists between the entrance face and the light-converging point of laser light. Therefore, the laser light will not be scattered by modified regions which have already been formed, whereby each modified region can be formed uniformly.
[0104] The modified region includes at least one of a crack region where a crack is generated within the object to be processed, a molten processed region which is melted within the object to be processed, and a refractive index change region where refractive index is changed within the object to be processed.
[0105] The laser processing method in accordance with an aspect of the present invention comprises a step of irradiating an object to be processed with laser light while locating a light-converging point of laser light within the object to be processed through a light entrance face of the laser light with respect to the object to be processed and locating the light-converging point at a position closer to or farther from the entrance face than is a half thickness position in the thickness direction of the object to be processed, so as to form a modified region within the object along a line along which the object is intended to be cut in the object.
[0106] In the laser processing method in accordance with the present invention, the modified region is formed on the entrance face (e.g., surface) and on the side of the face (e.g., rear face) opposing the entrance face within the object to be processed within the object to be processed when the light-converging point of laser light is located at a position closer to and farther from the entrance face than is a half thickness position in the thickness direction, respectively. When a fracture extending along a line along which the object is intended to be cut is generated on the surface or rear face of an object to be processed, the object can be cut easily. The laser processing method in accordance with this aspect of the present invention can form a modified region on the surface or rear face side within the object to be processed. This can make it easier to form the surface or rear face with a fracture extending along the line along which the object is intended to be cut, whereby the object to be processed can be cut easily. As a result, the laser processing method in accordance with this aspect of the present invention enables efficient cutting.
[0107] The laser processing method in accordance with this aspect of the present invention may be configured such that the entrance face is formed with at least one of an electronic device and an electrode pattern, whereas the light-converging point of laser light irradiating the object to be processed is located at a position closer to the entrance face than is the half thickness position in the thickness direction. The laser processing method in accordance with this aspect of the present invention grows a crack from the modified region toward the entrance face (e.g., surface) and its opposing face (e.g., rear face), thereby cutting the object to be processed. When the modified region is formed on the entrance face side, the distance between the modified region and the entrance face is relatively short, so that the deviation in the growth direction of crack can be made smaller. Therefore, when the entrance face of the object to be processed is formed with an electronic device or an electrode pattern, cutting is possible without damaging the electronic device or the like. The electronic device refers to a semiconductor device, a display device such as liquid crystal, a piezoelectric device, or the like.
[0108] The laser processing method in accordance with an aspect of the present invention comprises a first step of irradiating an object to be processed with pulse laser light while locating a light-converging point of the pulse laser light within the object, so as to form a first modified region caused by multiphoton absorption within the object along a first line along which the object is intended to be cut in the object; and a second step of irradiating, after the first step, the object with pulse laser light while locating the light-converging point of laser light at a position different from the light-converging point of laser light in the first step in the thickness direction of the object to be processed within the object, so as to form a second modified region caused by multiphoton absorption extending along a second line along which the object is intended to be cut and three-dimensionally crossing the first modified region within the object.
[0109] In a cutting process in which cross-sections of an object to be processed cross each other, a modified region and another modified region are not superposed on each other at a location to become the crossing position between the cross sections in the laser processing method in accordance with this aspect of the present invention, whereby the cutting precision at the crossing position can be prevented from deteriorating. This enables cutting with a high precision.
[0110] The laser processing method in accordance with this aspect of the present invention can form the second modified region closer to the entrance face of the object to be processed with respect to the laser light than is the first modified region. This keeps the laser light irradiated at the time of forming the second modified region at the location to become the crossing position from being scattered by the first modified region, whereby the second modified region can be formed uniformly.
[0111] The laser processing methods in accordance with the foregoing aspects of the present invention explained in the foregoing have the following modes:
[0112] When the object to be processed is irradiated with laser light under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, a modified region including a crack region can be formed within the object to be processed. This generates a phenomenon of an optical damage caused by multiphoton absorption within the object to be processed. This optical damage induces a thermal distortion within the object to be processed, thereby forming a crack region within the object to be processed. This crack region is an embodiment of the above-mentioned modified region. An embodiment of the object to be processed in this laser processing method is a member including glass. The peak power density refers to the electric field intensity of pulse laser light at the light-converging point.
[0113] When the object to be processed is irradiated with laser light under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point, a modified region including a molten processed region can be formed within the object to be processed. Here, the inside of the object to be processed is locally heated by multiphoton absorption. This heating forms a molten processed region within the object to be processed. This molten processed region is an embodiment of the above-mentioned modified region. An embodiment of the object to be processed in this laser processing method is a member including a semiconductor material.
[0114] When the object to be processed is irradiated with laser light under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 ns or less at the light-converging point, a modified region including a refractive index change region which is a region with a changed refractive index can also be formed within the object to be processed. When multiphoton absorption is generated within the object to be processed with a very short pulse width as such, the energy caused by multiphoton absorption is not transformed into thermal energy, so that a permanent structural change such as ionic valence change, crystallization, or polarization orientation is induced within the object, whereby a refractive index change region is formed. This refractive index change region is an embodiment of the above-mentioned modified region. An embodiment of the object to be processed in this laser processing method is a member including glass.
[0115] Adjustment of the position of the light-converging point of laser light irradiating the object to be processed in the thickness direction can include a first calculating step of defining a desirable position in the thickness direction of the light-converging point of laser light irradiating the object to be processed as a distance from the entrance face to the inside and dividing the distance by the refractive index of the object to be processed with respect to the laser light irradiating the object, so as to calculate data of a first relative movement amount of the object in the thickness direction; a second calculating step of calculating data of a second relative movement amount of the object in the thickness direction required for positioning the light-converging point of laser light irradiating the object to be processed at the entrance face; a first moving step of relatively moving the object in the thickness direction according to the data of second relative movement amount; and a second moving step of relatively moving the object in the thickness direction according to the data of first relative movement amount after the first moving step. This adjusts the position of the light-converging point of laser light in the thickness direction of the object to be processed at a predetermined position within the object. Namely, with reference to the entrance face, the product of the relative movement amount of the object to be processed in the thickness direction of the object and the refractive index of the object with respect to the laser light irradiating the object becomes the distance from the entrance face to the light-converging point of laser light. Therefore, when the object to be processed is moved by the relative movement amount obtained by dividing the distance from the entrance to the inside of the object by the above-mentioned refractive index, the light-converging point of laser light can be aligned with a desirable position in the thickness direction of the object.
[0116] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; first moving means for relatively moving the light-converging point converged by the light-converging means along a line along which the object is intended to be cut in an object to be processed; storing means for storing data of a first relative movement amount of the object to be processed in the thickness direction for locating the light-converging position of pulse laser light converged by the light-converging means at a desirable position within the object to be processed, the data of first relative movement amount being obtained by defining the desirable position as a distance from the entrance face where the pulse laser light emitted from the laser light source enters the object to be processed to the inside thereof and dividing the distance by the refractive index of the object to be processed with respect to the pulse laser light emitted from the laser light source; calculating means for calculating data of a second relative movement amount of the object to be processed in the thickness direction required for locating the light-converging point of the pulse laser light converged by the light-converging means at the entrance face; and second moving means for relatively moving the object to be processed in the thickness direction according to the data of first relative movement amount stored by the storage means and the data of second relative movement amount calculated by the calculating means.
[0117] The laser processing apparatus in accordance with an aspect of the present invention comprises a laser light source for emitting pulse laser light having a pulse width of 1 μs or less; light-converging means for converging the pulse laser light emitted from the laser light source such that the pulse laser light attains a peak power density of at least 1×10 8 (W/cm 2 ) at a light-converging point; means for locating the light-converging point of the pulse laser light emitted from the laser light source within an object to be processed; means for adjusting the position of the pulse laser light converged by the light-converging means within the thickness of the object to be processed; and moving means for relatively moving the light-converging point of pulse laser light along a line along which the object is intended to be cut in the object to be processed.
[0118] For the same reason as that in the laser processing methods in accordance with the above-mentioned aspects of the present invention, the laser processing apparatus in accordance with these aspects of the present invention enable laser processing without generating melt or unnecessary fractures deviating from the line along which the object is intended to be cut in the surface of the object to be processed, and laser processing in which the position of the light-converging point of pulse laser light is regulated in the thickness direction of the object to be processed within the object.
[0119] The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention.
[0120] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific embodiments, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0121] FIG. 1 is a plan view of an object to be processed during laser processing by the laser processing method in accordance with an embodiment;
[0122] FIG. 2 is a sectional view of the object to be processed shown in FIG. 1 taken along the line II-II;
[0123] FIG. 3 is a plan view of the object to be processed after laser processing effected by the laser processing method in accordance with the embodiment;
[0124] FIG. 4 is a sectional view of the object to be processed shown in FIG. 3 taken along the line IV-IV;
[0125] FIG. 5 is a sectional view of the object to be processed shown in FIG. 3 taken along the line V-V;
[0126] FIG. 6 is a plan view of the object to be processed cut by the laser processing method in accordance with the embodiment;
[0127] FIG. 7 is a graph showing relationships between the electric field intensity and the magnitude of crack in the laser processing method in accordance with the embodiment;
[0128] FIG. 8 is a sectional view of the object to be processed in a first step of the laser processing method in accordance with the embodiment;
[0129] FIG. 9 is a sectional view of the object to be processed in a second step of the laser processing method in accordance with the embodiment;
[0130] FIG. 10 is a sectional view of the object to be processed in a third step of the laser processing method in accordance with the embodiment;
[0131] FIG. 11 is a sectional view of the object to be processed in a fourth step of the laser processing method in accordance with the embodiment;
[0132] FIG. 12 is a view shoring a photograph of a cross section in a part of a silicon wafer cut by the laser processing method in accordance with the embodiment;
[0133] FIG. 13 is a graph showing relationships between the laser light wavelength and the transmittance within a silicon substrate in the laser processing method in accordance with the embodiment;
[0134] FIG. 14 is a schematic diagram of a laser processing apparatus usable in the laser processing method in accordance with a first embodiment of the embodiment;
[0135] FIG. 15 is a flowchart for explaining the laser processing method in accordance with the first embodiment of the present invention;
[0136] FIG. 16 is a plan view of an object to be processed for explaining a pattern which can be cut by the laser processing method in accordance with the first embodiment of the embodiment;
[0137] FIG. 17 is a schematic view for explaining the laser processing method in accordance with the first embodiment of the embodiment with a plurality of laser light sources;
[0138] FIG. 18 is a schematic view for explaining another laser processing method in accordance with the first embodiment of the embodiment with a plurality of laser light sources;
[0139] FIG. 19 is a schematic plan view showing a piezoelectric device wafer in a state held by a wafer sheet in the second embodiment of the embodiment;
[0140] FIG. 20 is a schematic sectional view showing a piezoelectric device wafer in a state held by the wafer sheet in the second embodiment of the embodiment;
[0141] FIG. 21 is a flowchart for explaining the cutting method in accordance with the second embodiment of the embodiment;
[0142] FIG. 22 is a sectional view of a light-transmitting material irradiated with laser light by the cutting method in accordance with the second embodiment of the embodiment;
[0143] FIG. 23 is a plan view of the light-transmitting material irradiated with laser light by the cutting method in accordance with the second embodiment of the embodiment;
[0144] FIG. 24 is a sectional view of the light-transmitting material shown in FIG. 23 taken along the line XXIV-XXIV;
[0145] FIG. 25 is a sectional view of the light-transmitting material shown in FIG. 23 taken along the line XXV-XXV;
[0146] FIG. 26 is a sectional view of the light-transmitting material shown in FIG. 23 taken along the line XXV-XXV when the light-converging point moving speed is made lower;
[0147] FIG. 27 is a sectional view of the light-transmitting material shown in FIG. 23 taken along the line XXV-XXV when the light-converging point moving speed is made further lower;
[0148] FIG. 28 is a sectional view of a piezoelectric device wafer or the like showing a first step of the cutting method in accordance with the second embodiment of the embodiment;
[0149] FIG. 29 is a sectional view of the piezoelectric device wafer or the like showing a second step of the cutting method in accordance with the second embodiment of the embodiment;
[0150] FIG. 30 is a sectional view of the piezoelectric device wafer or the like showing a third step of the cutting method in accordance with the second embodiment of the embodiment;
[0151] FIG. 31 is a sectional view of the piezoelectric device wafer or the like showing a fourth step of the cutting method in accordance with the second embodiment of the embodiment;
[0152] FIG. 32 is a sectional view of the piezoelectric device wafer or the like showing a fifth step of the cutting method in accordance with the second embodiment of the embodiment;
[0153] FIG. 33 is a view showing a photograph of a plane of a sample within which a crack region is formed upon irradiation with linearly polarized pulse laser light;
[0154] FIG. 34 is a view showing a photograph of a plane of a sample within which a crack region is formed upon irradiation with circularly polarized pulse laser light;
[0155] FIG. 35 is a sectional view of the sample shown in FIG. 33 taken along the line XXXV-XXXV;
[0156] FIG. 36 is a sectional view of the sample shown in FIG. 34 taken along the line XXXVI-XXXVI;
[0157] FIG. 37 is a plan view of the part of object to be processed extending along a line along which the object is intended to be cut, in which a crack region is formed by the laser processing method in accordance with a third embodiment of the embodiment;
[0158] FIG. 38 is a plan view of the part of object to be processed extending along a line along which the object is intended to be cut, in which a crack region is formed by a comparative laser processing method;
[0159] FIG. 39 is a view showing elliptically polarized laser light in accordance with the third embodiment of the embodiment, and a crack region formed thereby;
[0160] FIG. 40 is a schematic diagram of the laser processing apparatus in accordance with the third embodiment of the embodiment;
[0161] FIG. 41 is a perspective view of a quarter-wave plate included in an ellipticity regulator in accordance with the third embodiment of the embodiment;
[0162] FIG. 42 is a perspective view of a half-wave plate included in a 90° rotation regulator part in accordance with the third embodiment of the embodiment;
[0163] FIG. 43 is a flowchart for explaining the laser processing method in accordance with the third embodiment of the embodiment;
[0164] FIG. 44 is a plan view of a silicon wafer irradiated with elliptically polarized laser light by the laser processing method in accordance with the third embodiment of the embodiment;
[0165] FIG. 45 is a plan view of a silicon wafer irradiated with linearly polarized laser light by the laser processing method in accordance with the third embodiment of the embodiment;
[0166] FIG. 46 is a plan view of a silicon wafer in which the silicon wafer shown in FIG. 44 is irradiated with elliptically polarized laser light by the laser processing method in accordance with the third embodiment of the embodiment;
[0167] FIG. 47 is a plan view of a silicon wafer in which the silicon wafer shown in FIG. 45 is irradiated with linearly polarized laser light by the laser processing method in accordance with the third embodiment of the embodiment;
[0168] FIG. 48 is a schematic diagram of the laser processing apparatus in accordance with a fourth embodiment of the embodiment;
[0169] FIG. 49 is a plan view of a silicon wafer in which the silicon wafer shown in FIG. 44 is irradiated with elliptically polarized laser light by the laser processing method in accordance with the fourth embodiment of the embodiment;
[0170] FIG. 50 is a plan view of the object to be processed in the case where a crack spot is formed relatively large by using the laser processing method in accordance with a fifth embodiment of the embodiment;
[0171] FIG. 51 is a sectional view taken along LI-LI on the line along which the object is intended to be cut shown in FIG. 50 ;
[0172] FIG. 52 is a sectional view taken along LII-LII orthogonal to the line along which the object is intended to be cut shown in FIG. 50 ;
[0173] FIG. 53 is a sectional view taken along LIII-LIII orthogonal to the line along which the object is intended to be cut shown in FIG. 50 ;
[0174] FIG. 54 is a sectional view taken along LIV-LIV orthogonal to the line along which the object is intended to be cut shown in FIG. 50 ;
[0175] FIG. 55 is a plan view of the object to be processed shown in FIG. 50 cut along the line along which the object is intended to be cut;
[0176] FIG. 56 is a sectional view of the object to be processed taken along the line along which the object is intended to be cut in the case where a crack spot is formed relatively small by using the laser processing method in accordance with the fifth embodiment of the embodiment;
[0177] FIG. 57 is a plan view of the object to be processed shown in FIG. 56 cut along the line along which the object is intended to be cut;
[0178] FIG. 58 is a sectional view of the object to be processed showing a state where pulse laser light is converged within the object by using a light-converging lens having a predetermined numerical aperture;
[0179] FIG. 59 is a sectional view of the object to be processed including a crack spot formed due to the multiphoton absorption caused by irradiation with laser light shown in FIG. 58 ;
[0180] FIG. 60 is a sectional view of the object to be processed in the case where a light-converging lens having a numerical aperture greater than that of the embodiment shown in FIG. 58 is used;
[0181] FIG. 61 is a sectional view of the object to be processed including a crack spot formed due to the multiphoton absorption caused by irradiation with laser light shown in FIG. 60 ;
[0182] FIG. 62 is a sectional view of the object to be processed in the case where pulse laser light having a power lower than that of the embodiment shown in FIG. 58 is used;
[0183] FIG. 63 is a sectional view of the object to be processed including a crack spot formed due to the multiphoton absorption caused by irradiation with laser light shown in FIG. 62 ;
[0184] FIG. 64 is a sectional view of the object to be processed in the case where pulse laser light having a power lower than that of the embodiment shown in FIG. 60 is used;
[0185] FIG. 65 is a sectional view of the object to be processed including a crack spot formed due to the multiphoton absorption caused by irradiation with laser light shown in FIG. 64 ;
[0186] FIG. 66 is a sectional view taken along LXVI-LXVI orthogonal to the line along which the object is intended to be cut shown in FIG. 57 ;
[0187] FIG. 67 is a schematic diagram showing the laser processing apparatus in accordance with the fifth embodiment of the embodiment;
[0188] FIG. 68 is a block diagram showing a part of an embodiment of overall controller provided in the laser processing apparatus in accordance with the fifth embodiment of the embodiment;
[0189] FIG. 69 is a view showing an embodiment of table of a correlation storing section included in the overall controller of the laser processing apparatus in accordance with the fifth embodiment of the embodiment;
[0190] FIG. 70 is a view showing another embodiment of the table of the correlation storing section included in the overall controller of the laser processing apparatus in accordance with the fifth embodiment of the embodiment;
[0191] FIG. 71 is a view showing still another embodiment of the table of the correlation storing section included in the overall controller of the laser processing apparatus in accordance with the fifth embodiment of the embodiment;
[0192] FIG. 72 is a schematic diagram of the laser processing apparatus in accordance with a sixth embodiment of the embodiment;
[0193] FIG. 73 is a view showing the convergence of laser light caused by a light-converging lens in the case where no beam expander is disposed;
[0194] FIG. 74 is a view showing the convergence of laser light caused by the light-converging lens in the case where a beam expander is disposed;
[0195] FIG. 75 is a schematic diagram of the laser processing apparatus in accordance with a seventh embodiment of the embodiment;
[0196] FIG. 76 is a view showing the convergence of laser light caused by the light-converging lens in the case where no iris diaphragm is disposed;
[0197] FIG. 77 is a view showing the convergence of laser light caused by the light-converging lens in the case where an iris diaphragm is disposed;
[0198] FIG. 78 is a block diagram showing an embodiment of overall controller provided in a modified embodiment of the laser processing apparatus in accordance with the embodiment;
[0199] FIG. 79 is a block diagram of another embodiment of overall controller provided in the modified embodiment of the laser processing apparatus in accordance with the embodiment;
[0200] FIG. 80 is a block diagram of still another embodiment of overall controller provided in the modified embodiment of the laser processing apparatus in accordance with the embodiment;
[0201] FIG. 81 is a plan view of an embodiment of the part of object to be processed extending along a line along which the object is intended to be cut, in which a crack region is formed by the laser processing method in accordance with an eighth embodiment of the embodiment;
[0202] FIG. 82 is a plan view of another embodiment of the part of object to be processed extending along the line along which the object is intended to be cut, in which a crack region is formed by the laser processing method in accordance with the eighth embodiment of the embodiment;
[0203] FIG. 83 is a plan view of still another embodiment of the part of object to be processed extending along the line along which the object is intended to be cut, in which a crack region is formed by the laser processing method in accordance with the eighth embodiment of the embodiment;
[0204] FIG. 84 is a schematic diagram of a Q-switch laser provided in a laser light source of the laser processing apparatus in accordance with the eighth embodiment of the embodiment;
[0205] FIG. 85 is a block diagram showing a part of an embodiment of overall controller of the laser processing apparatus in accordance with the eighth embodiment of the embodiment;
[0206] FIG. 86 is a block diagram showing a part of another embodiment of overall controller of the laser processing apparatus in accordance with the eighth embodiment of the embodiment;
[0207] FIG. 87 is a block diagram showing a part of still another embodiment of overall controller of the laser processing apparatus in accordance with the eighth embodiment of the embodiment;
[0208] FIG. 88 is a block diagram showing a part of still another embodiment of overall controller of the laser processing apparatus in accordance with the eighth embodiment of the embodiment;
[0209] FIG. 89 is a perspective view of an embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with a ninth embodiment of the embodiment;
[0210] FIG. 90 is a perspective view of the object to be processed formed with a crack extending from the crack region shown in FIG. 89 ;
[0211] FIG. 91 is a perspective view of another embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with the ninth embodiment of the embodiment;
[0212] FIG. 92 is a perspective view of still another embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with the ninth embodiment of the embodiment;
[0213] FIG. 93 is a view showing the state where a light-converging point of laser light is positioned on the surface of the object to be processed;
[0214] FIG. 94 is a view showing the state where a light-converging point of laser light is positioned within the object to be processed;
[0215] FIG. 95 is a flowchart for explaining the laser processing method in accordance with the ninth embodiment of the embodiment;
[0216] FIG. 96 is a perspective view of an embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with a tenth embodiment of the embodiment;
[0217] FIG. 97 is a partly sectional view of the object to be processed shown in FIG. 96 ;
[0218] FIG. 98 is a perspective view of another embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with the tenth embodiment of the embodiment;
[0219] FIG. 99 is a partly sectional view of the object to be processed shown in FIG. 98 ; and
[0220] FIG. 100 is a perspective view of still another embodiment of the object to be processed within which a crack region is formed by using the laser processing method in accordance with the tenth embodiment of the embodiment.
[0221] FIG. 101 is a flowchart for explaining the laser processing method in accordance with the eleventh embodiment of the present invention;
[0222] FIG. 102 is a sectional view of the object including a crack region during laser processing in the modified region forming step in accordance with the eleventh and twelfth embodiments.
[0223] FIG. 103 is a sectional view of the object including a crack region during laser processing in the stress step in accordance with the eleventh embodiment.
[0224] FIG. 104 is a flowchart for explaining the laser processing method in accordance with the twelfth embodiment of the present invention.
[0225] FIG. 105 is a sectional view of the object including a crack region during laser processing in the stress step in accordance with the twelfth embodiment.
[0226] FIG. 106 shows an film expansion apparatus used in the thirteenth embodiments.
[0227] FIG. 107 is for explanation of the expansion status of the adhesive and expansive sheet in the thirteenth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0228] In the following, a preferred embodiment of the present invention will be explained with reference to the drawings. The laser processing method and laser processing apparatus of an embodiment in accordance with the present invention is embodiment form a modified region by multiphoton absorption. The multiphoton absorption is a phenomenon occurring when the intensity of laser light is made very high. First, the multiphoton absorption will be explained in brief.
[0229] A material becomes optically transparent when the energy hν of a photon is lower than the bandgap E G of absorption of the material. Therefore, the condition under which absorption occurs in the material is hν>E G . Even when optically transparent, however, absorption occurs in the material under the condition of nhν>E G (n=2, 3, 4, . . . ) when the intensity of laser light is made very high. This phenomenon is known as multiphoton absorption. In the case of pulse wave, the intensity of laser light is determined by the peak power density (W/cm 2 ) of laser light at the light-converging point, whereas the multiphoton absorption occurs under the condition with a peak power density of at least 1×10 8 (W/cm 2 ), for embodiment. The peak power density is determined by (energy of laser light at the light-converging point per pulse)/(beam spot cross-sectional area of laser light×pulse width). In the case of a continuous wave, the intensity of laser light is determined by the electric field intensity (W/cm 2 ) of laser light at the light-converging point.
[0230] The principle of laser processing in accordance with the embodiment utilizing such multiphoton absorption will now be explained with reference to FIGS. 1 to 6 . FIG. 1 is a plan view of an object to be processed 1 during laser processing. FIG. 2 is a sectional view of the object 1 shown in FIG. 1 taken along the line II-II. FIG. 3 is a plan view of the object 1 after laser processing. FIG. 4 is a sectional view of the object 1 shown in FIG. 3 taken along the line IV-IV. FIG. 5 is a sectional view of the object 1 shown in FIG. 3 taken along the line V-V. FIG. 6 is a plan view of the cut object 1 .
[0231] As shown in FIGS. 1 and 2 , the object 1 has a surface 3 with a line 5 along which the object is intended to be cut. The line 5 along which the object is intended to be cut is a linearly extending virtual line. In the laser processing of an embodiment in accordance with the present invention, the object 1 is irradiated with laser light L while locating a light-converging point P within the object 1 under a condition generating multiphoton absorption, so as to form a modified region 7 . The light-converging point refers to a location at which the laser light L is converged.
[0232] By relatively moving the laser light L along the line 5 along which the object is intended to be cut (i.e., along the direction of arrow A), the light-converging point P is moved along the line 5 along which the object is intended to be cut. This forms the modified region 7 along the line 5 along which the object is intended to be cut only within the object 1 as shown in FIGS. 3 to 5 . In the laser processing method in accordance with the embodiment, the modified region 7 is not formed by heating the object 1 due to the absorption of laser light L therein. The laser light L is transmitted through the object 1 , so as to generate multiphoton absorption therewithin, thereby forming the modified region 7 . Therefore, the laser light L is hardly absorbed at the surface 3 of the object 1 , whereby the surface 3 of the object 1 will not melt.
[0233] If a starting point exists in a part to be cut when cutting the object 1 , the object 1 will break from the starting point, whereby the object 1 can be cut with a relatively small force as shown in FIG. 6 . Hence, the object 1 can be cut without generating unnecessary fractures in the surface 3 of the object 1 .
[0234] The following two cases seem to exist in the cutting of the object to be processed using the modified region as a starting point. The first case is where, after the modified region is formed, an artificial force is applied to the object, whereby the object breaks while using the modified region as a starting point, and thus is cut. This is cutting in the case where the object to be processed has a large thickness, for embodiment. Applying an artificial force includes, for embodiment, applying a bending stress or shearing stress to the object along the line along which the object is intended to be cut in the object to be processed or imparting a temperature difference to the object so as to generate a thermal stress. Another case is where a modified region is formed, so that the object naturally breaks in the cross-sectional direction (thickness direction) of the object while using the modified region as a starting point, whereby the object is cut. This can be achieved by a single modified region when the thickness of the object is small, and by a plurality of modified regions formed in the thickness direction when the thickness of the object to be processed is large. Breaking and cutting can be carried out with favorable control even in this naturally breaking case, since breaks will not reach the part formed with no modified region on the surface in the part to be cut, so that only the part formed with the modified region can be broken and cut. Such a breaking and cutting method with favorable controllability is quite effective, since semiconductor wafers such as silicon wafers have recently been prone to decrease their thickness.
[0235] The modified region formed by multiphoton absorption in the embodiment includes the following (1) to (3):
[0236] (1) Case where the Modified Region is a Crack Region Including One or a Plurality of Cracks
[0237] An object to be processed (e.g., glass or a piezoelectric material made of LiTaO 3 ) is irradiated with laser light while the light-converging point is located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point. This magnitude of pulse width is a condition under which a crack region can be formed only within the object to be processed while generating multiphoton absorption without causing unnecessary damages to the surface of the object. This generates a phenomenon of optical damage caused by multiphoton absorption within the object to be processed. This optical damage induces thermal distortion within the object to be processed, thereby forming a crack region therewithin. The upper limit of electric field intensity is 1×10 12 (W/cm 2 ), for embodiment. The pulse width is preferably 1 ns to 200 ns, for embodiment. The forming of a crack region caused by multiphoton absorption is described, for embodiment, in “Internal Marking of Glass Substrate by Solid-state Laser Harmonics”, Proceedings of 45 th Laser Materials Processing Conference (December 1998), pp. 23-28.
[0238] The inventor determined relationships between the electric field intensity and the magnitude of crack by an experiment. Conditions for the experiment are as follows:
(A) Object to be processed: Pyrex glass (having a thickness of 700 μm) (B) Laser
Light source: semiconductor laser pumping Nd:YAG laser Wavelength: 1064 nm Laser light spot cross-sectional area: 3.14×10 −8 cm 2 Oscillation mode: Q-switch pulse Repetition frequency: 100 kHz Pulse width: 30 ns Output: output<1 mJ/pulse Laser light quality: TEM 00 Polarization characteristic: linear polarization
(C) Light-converging lens
Transmittance with respect to laser light wavelength: 60%
(D) Moving speed of a mounting table mounting the object to be processed: 100 mm/sec
[0253] The laser light quality of TEM 00 indicates that the light convergence is so high that light can be converged up to about the wavelength of laser light.
[0254] FIG. 7 is a graph showing the results of the above-mentioned experiment. The abscissa indicates peak power density. Since laser light is pulse laser light, its electric field intensity is represented by the peak power density. The ordinate indicates the size of a crack part (crack spot) formed within the object to be processed by one pulse of laser light. An assembly of crack spots forms a crack region. The size of a crack spot refers to that of the part of dimensions of the crack spot yielding the maximum length. The data indicated by black circles in the graph refers to a case where the light-converging glass (C) has a magnification of ×100 and a numerical aperture (NA) of 0.80. On the other hand, the data indicated by white circles in the graph refers to a case where the light-converging glass (C) has a magnification of ×50 and a numerical aperture (NA) of 0.55. It is seen that crack spots begin to occur within the object to be processed when the peak power density reaches 10 11 (W/cm 2 ), and become greater as the peak power density increases.
[0255] A mechanism by which the object to be processed is cut upon formation of a crack region in the laser processing in accordance with the embodiment will now be explained with reference to FIGS. 8 to 11 . As shown in FIG. 8 , the object to be processed 1 is irradiated with laser light L while locating the light-converging point P within the object 1 under a condition where multiphoton absorption occurs, so as to form a crack region 9 therewithin. The crack region 9 is a region including one or a plurality of cracks. As shown in FIG. 9 , the crack further grows while using the crack region 9 as a starting point. As shown in FIG. 10 , the crack reaches the surface 3 and rear face 21 of the object 1 . As shown in FIG. 11 , the object 1 breaks, so as to be cut. The crack reaching the surface and rear face of the object to be processed may grow naturally or grow as a force is applied to the object.
[0256] (2) Case where the Modified Region is a Molten Processed Region
[0257] An object to be processed (e.g., a semiconductor material such as silicon) is irradiated with laser light while the light-converging point is located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 μs or less at the light-converging point. As a consequence, the inside of the object to be processed is locally heated by multiphoton absorption. This heating forms a molten processed region within the object to be processed. The molten processed region refers to at least one of a region once melted and then re-solidified, a region in a melted state, and a region in the process of re-solidifying from its melted state. The molten processed region may also be defined as a phase-changed region or a region having changed its crystal structure. The molten processed region may also be regarded as a region in which a certain structure has changed into another structure in monocrystal, amorphous, and polycrystal structures. Namely, it refers to a region in which a monocrystal structure has changed into an amorphous structure, a region in which a monocrystal structure has changed into a polycrystal structure, and a region in which a monocrystal structure has changed into a structure including an amorphous structure and a polycrystal structure, for embodiment. When the object to be processed is a silicon monocrystal structure, the molten processed region is an amorphous silicon structure, for embodiment. The upper limit of electric field intensity is 1×10 12 (W/cm 2 ), for embodiment. The pulse width is preferably 1 ns to 200 ns, for embodiment.
[0258] By an experiment, the inventor has verified that a molten processed region is formed within a silicon wafer. Conditions for the experiment is as follows:
(A) Object to be processed: silicon wafer (having a thickness of 350 μm and an outer diameter of 4 inches) (B) Laser
Light source: semiconductor laser pumping Nd:YAG laser Wavelength: 1064 nm Laser light spot cross-sectional area: 3.14×10 −8 cm 2 Oscillation mode: Q-switch pulse Repetition frequency: 100 kHz Pulse width: 30 ns Output: 20 μJ/pulse Laser light quality: TEM 00 Polarization characteristic: linear polarization
(C) Light-converging lens
Magnification: ×50 NA: 0.55 Transmittance with respect to laser light wavelength: 60%
(D) Moving speed of a mounting table mounting the object to be processed: 100 mm/sec
[0275] FIG. 12 is a view showing a photograph of across section in a part of a silicon wafer cut by laser processing under the above-mentioned conditions. A molten processed region 13 is formed within a silicon wafer 11 . The size of the molten processed region formed under the above-mentioned conditions is about 100 μm in the thickness direction.
[0276] The forming of the molten processed region 13 by multiphoton absorption will be explained. FIG. 13 is a graph showing relationships between the wavelength of laser light and the transmittance within the silicon substrate. Here, respective reflecting components on the surface and rear face sides of the silicon substrate are eliminated, whereby only the transmittance therewithin is represented. The above-mentioned relationships are shown in the cases where the thickness t of the silicon substrate is 50 μm, 100 μm, 200 μm, 500 μm, and 1000 μm, respectively.
[0277] For embodiment, it is seen that laser light transmits through the silicon substrate by at least 80% at 1064 nm, which is the wavelength of Nd:YAG laser, when the silicon substrate has a thickness of 500 μm or less. Since the silicon wafer 11 shown in FIG. 12 has a thickness of 350 μm, the molten processed region caused by multiphoton absorption is formed near the center of the silicon wafer, i.e., at a part separated from the surface by 175 μm. The transmittance in this case is 90% or greater with reference to a silicon wafer having a thickness of 200 μm, whereby the laser light is absorbed within the silicon wafer 11 only slightly and is substantially transmitted therethrough. This means that the molten processed region is not formed by laser light absorption within the silicon wafer 11 (i.e., not formed upon usual heating with laser light), but by multiphoton absorption. The forming of a molten processed region by multiphoton absorption is described, for embodiment, in “Processing Characteristic evaluation of Silicon by Picosecond Pulse Laser”, Preprints of the National Meeting of Japan Welding Society , No. 66 (April 2000), pp. 72-73.
[0278] Here, a fracture is generated in the cross-sectional direction while using the molten processed region as a starting point, whereby the silicon wafer is cut when the fracture reaches the surface and rear face of the silicon wafer. The fracture reaching the surface and rear face of the object to be processed may grow naturally or grow as a force is applied to the object. The fracture naturally grows from the molten processed region to the surface and rear face of the silicon wafer in one of the cases where the fracture grows from a region once melted and then re-solidified, where the fracture grows from a region in a melted state, and where the fracture grows from a region in the process of re-solidifying from a melted state. In any of these cases, the molten processed region is formed only within the cross section after cutting as shown in FIG. 12 . When a molten processed region is formed within the object to be processed, unnecessary fractures deviating from a line along which the object is intended to be cut are hard to occur at the time of breaking and cutting, which makes it easier to control the breaking and cutting.
[0279] (3) Case where the Modified Region is a Refractive Index Change Region
[0280] An object to be processed (e.g., glass) is irradiated with laser light while the light-converging point is located therewithin under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) and a pulse width of 1 ns or less at the light-converging point. When multiphoton absorption is generated within the object to be processed with a very short pulse width, the energy caused by multiphoton absorption is not transformed into thermal energy, so that a permanent structural change such as ionic valence change, crystallization, or polarization orientation is induced within the object, whereby a refractive index change region is formed. The upper limit of electric field intensity is 1×10 12 (W/cm 2 ), for embodiment. The pulse width is preferably 1 ns or less, more preferably 1 μs or less, for embodiment. The forming of a refractive index change region by multiphoton absorption is described, for embodiment, in “Formation of Photoinduced Structure within Glass by Femtosecond Laser Irradiation”, Proceedings of 42 th Laser Materials Processing Conference (November 1997), pp. 105-111.
[0281] Specific embodiments according to the present invention will now be explained.
First Embodiment
[0282] The laser processing method in accordance with a first embodiment of the present invention will be explained. FIG. 14 is a schematic diagram of a laser processing apparatus 100 usable in this method. The laser processing apparatus 100 comprises a laser light source 101 for generating laser light L; a laser light source controller 102 for controlling the laser light source 101 so as to regulate the output and pulse width of laser light L and the like; a dichroic mirror 103 , arranged so as to change the orientation of the optical axis of laser light L by 90°, having a function of reflecting the laser light L; a light-converging lens 105 for converging the laser light L reflected by the dichroic mirror 103 ; a mounting table 107 for mounting an object to be processed 1 irradiated with the laser light L converged by the light-converging lens 105 ; an X-axis stage 109 for moving the mounting table 107 in the X-axis direction; a Y-axis stage 111 for moving the mounting table 107 in the Y-axis direction orthogonal to the X-axis direction; a Z-axis stage 113 for moving the mounting table 107 in the Z-axis direction orthogonal to X- and Y-axis directions; and a stage controller 115 for controlling the movement of these three stages 109 , 111 , 113 .
[0283] The Z-axis direction is a direction orthogonal to the surface 3 of the object to be processed 1 , thus becoming the direction of focal depth of laser light L incident on the object 1 . Therefore, moving the Z-axis stage 113 in the Z-axis direction can locate the light-converging point P of laser light L within the object 1 . This movement of light-converging point P in X(Y)-axis direction is effected by moving the object 1 in the X(Y)-axis direction by the X(Y)-axis stage 109 ( 111 ). The X(Y)-axis stage 109 ( 111 ) is an embodiment of moving means.
[0284] The laser light source 101 is an Nd:YAG laser generating pulse laser light. Known as other kinds of laser usable as the laser light source 101 include Nd:YVO 4 laser, Nd:YLF laser, and titanium sapphire laser. For forming a crack region or molten processed region, Nd:YAG laser, Nd:YVO 4 laser, and Nd:YLF laser are used preferably. For forming a refractive index change region, titanium sapphire laser is used preferably.
[0285] Though pulse laser light is used for processing the object 1 in the first embodiment, continuous wave laser light may also be used as long as it can generate multiphoton absorption. In the present invention, laser light means to include laser beams. The light-converging lens 105 is an embodiment of light-converging means. The Z-axis stage 113 is an embodiment of means for locating the light-converging point within the object to be processed. The light-converging point of laser light can be located within the object to be processed by relatively moving the light-converging lens 105 in the Z-axis direction.
[0286] The laser processing apparatus 100 further comprises an observation light source 117 for generating a visible light beam for irradiating the object to be processed 1 mounted on the mounting table 107 ; and a visible light beam splitter 119 disposed on the same optical axis as that of the dichroic mirror 103 and light-converging lens 105 . The dichroic mirror 103 is disposed between the beam splitter 119 and light-converging lens 105 . The beam splitter 119 has a function of reflecting about a half of a visual light beam and transmitting the remaining half therethrough, and is arranged so as to change the orientation of the optical axis of the visual light beam by 90°. A half of the visible light beam generated by the observation light source 117 is reflected by the beam splitter 119 , and thus reflected visible light beam is transmitted through the dichroic mirror 103 and light-converging lens 105 , so as to illuminate the surf ace 3 of the object 1 including the line 5 along which the object is intended to be cut and the like.
[0287] The laser processing apparatus 100 further comprises an image pickup device 121 and an imaging lens 123 disposed on the same optical axis as that of the beam splitter 119 , dichroic mirror 103 , and light-converging lens 105 . An embodiment of the image pickup device 121 is a CCD (charge-coupled device) camera. The reflected light of the visual light beam having illuminated the surface 3 including the line 5 along which the object is intended to be cut and the like is transmitted through the light-converging lens 105 , dichroic mirror 103 , and beam splitter 119 and forms an image by way of the imaging lens 123 , whereas thus formed image is captured by the imaging device 121 , so as to yield imaging data.
[0288] The laser processing apparatus 100 further comprises an imaging data processor 125 for inputting the imaging data outputted from the imaging device 121 , an overall controller 127 for controlling the laser processing apparatus 100 as a whole, and a monitor 129 . According to the imaging data, the imaging data processor 125 calculates foal point data for locating the focal point of the visible light generated in the observation light source 117 onto the surface 3 . According to the focal point data, the stage controller 115 controls the movement of the Z-axis stage 113 , so that the focal point of visible light is located on the surface 3 . Hence, the imaging data processor 125 functions as an auto focus unit. Also, according to the imaging data, the imaging data processor 125 calculates image data such as an enlarged image of the surface 3 . The image data is sent to the overall controller 127 , subjected to various kinds of processing, and then sent to the monitor 129 . As a consequence, an enlarged image or the like is displayed on the monitor 129 .
[0289] Data from the stage controller 115 , image data from the imaging data processor 125 , and the like are fed into the overall controller 127 . According to these data as well, the overall controller 127 regulates the laser light source controller 102 , observation light source 117 , and stage controller 115 , thereby controlling the laser processing apparatus 100 as a whole. Thus, the overall controller 127 functions as a computer unit.
[0290] With reference to FIGS. 14 and 15 , the laser processing method in accordance with a first embodiment of the embodiment will now be explained. FIG. 15 is a flowchart for explaining this laser processing method. The object to be processed 1 is a silicon wafer.
[0291] First, alight absorption characteristic of the object 1 is determined by a spectrophotometer or the like which is not depicted. According to the results of measurement, a laser light source 101 generating laser light L having a wavelength to which the object 1 is transparent or exhibits a low absorption is chosen (S 101 ). Next, the thickness of the object 1 is measured. According to the result of measurement of thickness and the refractive index of the object 1 , the amount of movement of the object 1 in the Z-axis direction is determined (S 103 ). This is an amount of movement of the object 1 in the Z-axis direction with reference to the light-converging point of laser light L positioned at the surface 3 of the object 1 in order for the light-converging point P of laser light L to be positioned within the object 1 . This amount of movement is fed into the overall controller 127 .
[0292] The object 1 is mounted on the mounting table 107 of the laser processing apparatus 100 . Then, visible light is generated from the observation light source 117 , so as to illuminate the object 1 (S 105 ). The illuminated surface 3 of the object 1 including the line 5 along which the object is intended to be cut is captured by the image pickup device 121 . Thus obtained imaging data is sent to the imaging data processor 125 . According to the imaging data, the imaging data processor 125 calculates such focal point data that the focal point of visible light from the observation light source 117 is positioned at the surface 3 (S 107 ).
[0293] The focal point data is sent to the stage controller 115 . According to the focal point data, the stage controller 115 moves the Z-axis stage 113 in the Z-axis direction (S 109 ). As a consequence, the focal point of visible light from the observation light source 117 is positioned at the surface 3 . According to the imaging data, the imaging data processor 125 calculates enlarged image data of the surface 3 of the object including the line 5 along which the object is intended to be cut. The enlarged image data is sent to the monitor 129 by way of the overall controller 127 , whereby an enlarged image of the line 5 along which the object is intended to be cut and its vicinity is displayed on the monitor 129 .
[0294] Movement amount data determined at step S 103 has been fed into the overall controller 127 beforehand, and is sent to the stage controller 115 . According to the movement amount data, the stage controller 115 causes the Z-axis stage 113 to move the object 1 in the Z-axis direction at a position where the light-converging point P of laser light L is located within the object 1 (S 111 ).
[0295] Next, laser light L is generated from the laser light source 101 , so as to irradiate the line 5 along which the object is intended to be cut in the surface 3 of the object with the laser light L. Since the light-converging point P of laser light is positioned within the object 1 , a molten processed region is formed only within the object 1 . Subsequently, the X-axis stage 109 and Y-axis stage 111 are moved along the line along which the object is intended to be cut, so as to form a molten processed region along the line 5 along which the object is intended to be cut within the object 1 (S 113 ). Then, the object 1 is bent along the line 5 along which the object is intended to be cut, and thus is cut (S 115 ). This divides the object 1 into silicon chips.
[0296] Effects of the first embodiment will be explained. Here, the line 5 along which the object is intended to be cut is irradiated with the pulse laser light L under a condition causing multiphoton absorption while locating the light-converging point P within the object 1 . Then, the X-axis stage 109 and Y-axis stage 111 are moved, so as to move the light-converging point P along the line 5 along which the object is intended to be cut. As a consequence, a modified region (e.g., crack region, molten processed region, or refractive index change region) is formed within the object 1 along the line 5 along which the object is intended to be cut. When a certain starting point exists at a part to be cut in the object to be processed, the object can be cut by breaking it with a relatively small force. Therefore, breaking the object 1 along the line 5 along which the object is intended to be cut while using a modified region as a starting point can cut the object 1 with a relatively small force. This can cut the object 1 without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut in the surface 3 of the object 1 .
[0297] Also, in the first embodiment, the object 1 is irradiated with the pulse laser light L at the line 5 along which the object is intended to be cut under a condition generating multiphoton absorption in the object 1 while locating the light-converging point P within the object 1 . Therefore, the pulse laser light L is transmitted through the object 1 without substantially being absorbed at the surface 3 of the object 1 , whereby the surface 3 will not incur damages such as melting due to the forming of a modified region.
[0298] As explained in the foregoing, the first embodiment can cut the object 1 without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut and melt in the surface 3 of the object. Therefore, when the object is a semiconductor wafer, for embodiment, a semiconductor chip can be cut out from the semiconductor wafer without generating unnecessary fractures deviating from the line along which the object is intended to be cut and melt in the semiconductor chip. The same holds for objects to be processed whose surface is formed with electrode patterns, and those whose surface is formed with electronic devices such as piezoelectric wafers and glass substrates formed with display devices such as liquid crystals. Therefore, the first embodiment can improve the yield of products (e.g., semiconductor chips, piezoelectric device chips, and display devices such as liquid crystal) prepared by cutting the object to be processed.
[0299] Also, since the line 5 along which the object is intended to be cut in the surface 3 of the object 1 does not melt, the first embodiment can decrease the width of the line 5 along which the object is intended to be cut (the width being the interval between regions to become semiconductor chips in the case of a semiconductor wafer, for embodiment). This increases the number of products prepared from a single object to be processed 1 , whereby the productivity of products can be improved.
[0300] Since laser light is used for cutting the object 1 , the first embodiment enables processing more complicated than that obtained by dicing with a diamond cutter. For embodiment, even when the line 5 along which the object is intended to be cut has a complicated form as shown in FIG. 16 , the first embodiment allows cutting. These effects are similarly obtained in embodiments which will be explained later.
[0301] Not only a single laser light source but also a plurality of laser light sources may be provided. For embodiment, FIG. 17 is a schematic view for explaining the laser processing method in the first embodiment of the embodiment in which a plurality of laser light sources are provided. Here, the object 1 is irradiated with three laser beams emitted from respective laser light sources 15 , 17 , 19 from different directions while the light-converging point P is located within the object 1 . The respective laser beams from the laser light sources 15 , 17 are made incident on the object 1 from the surface 3 thereof. The laser beam from the laser light source 19 is made incident on the object 1 from the rear face 21 thereof. Since a plurality of laser light sources are used, this makes it possible for the light-converging point to have an electric field intensity with such a magnitude that multiphoton absorption occurs, even when laser light is continuous wave laser light having a power lower than that of pulse laser light. For the same reason, multiphoton absorption can be generated even without a light-converging lens. Though the light-converging point P is formed by the three laser light sources 15 , 17 , 19 , the present invention is not restricted thereto as long as a plurality of laser light sources exist therein.
[0302] FIG. 18 is a schematic view for explaining another laser processing method in accordance with the first embodiment of the embodiment in which a plurality of laser light sources are provided. This embodiment comprises three array light source sections 25 , 27 , 29 each having a plurality of laser light sources 23 aligning along the line 5 along which the object is intended to be cut. Among the array light source sections 25 , 27 , 29 , laser beams emitted from laser light sources 23 arranged in the same row form a single light-converging point (e.g., light-converging point P 1 ). This embodiment can form a plurality of light-converging points P 1 , P 2 , . . . along the line 5 along which the object is intended to be cut, whereby the processing speed can be improved. Also, in this embodiment, a plurality of rows of modified regions can be formed at the same time upon laser-scanning on the surface 3 in a direction orthogonal to the line 5 along which the object is intended to be cut.
Second Embodiment
[0303] A second embodiment of the present invention will now be explained. This embodiment is directed to a cutting method and cutting apparatus for a light-transmitting material. The light-transmitting material is an embodiment of the objects to be processed. In this embodiment, a piezoelectric device wafer (substrate) having a thickness of about 400 μm made of LiTaO 3 is used as a light-transmitting material.
[0304] The cutting apparatus in accordance with the second embodiment is constituted by the laser processing apparatus 100 shown in FIG. 14 and the apparatus shown in FIGS. 19 and 20 . The apparatus shown in FIGS. 19 and 20 will be explained. The piezoelectric device wafer 31 is held by a wafer sheet (film) 33 acting as holding means. In the wafer sheet 33 , the face on the side holding the piezoelectric device wafer 31 is made of an adhesive resin tape or the like, and has an elasticity. The wafer sheet 33 is set on a mounting table 107 while being held with a sample holder 35 . As shown in FIG. 19 , the piezoelectric device wafer 31 includes a number of piezoelectric device chips 37 which will be cut and separated later. Each piezoelectric device chip 37 has a circuit section 39 . The circuit section 39 is formed on the surface of the piezoelectric device wafer 31 for each piezoelectric device chip 37 , whereas a predetermined gap a (about 80 μm) is formed between adjacent circuit sections 39 . FIG. 20 shows a state where minute crack regions 9 as modified parts are formed within the piezoelectric device wafer 31 .
[0305] Next, with reference to FIG. 21 , the method of cutting a light-transmitting material in accordance with the second embodiment will be explained. First, a light absorption characteristic of the light-transmitting material (piezoelectric device wafer 31 made of LiTaO 3 in the second embodiment) to become a material to be cut is determined (S 201 ). The light absorption characteristic can be measured by using a spectrophotometer or the like. Once the light absorption characteristic is determined, a laser light source 101 generating laser light L having a wavelength to which the material to be cut is transparent or exhibits a low absorption is chosen according to the result of determination (S 203 ). In the second embodiment, a YAG laser of pulse wave (PW) type having a fundamental wave wavelength of 1064 nm is chosen. This YAG laser has a pulse repetition frequency of 20 Hz, a pulse width of 6 ns, and a pulse energy of 300 μJ. The spot diameter of laser light L emitted from the YAG laser is about 20 μm.
[0306] Next, the thickness of the material to be cut is measured (S 205 ). Once the thickness of the material to be cut is measured, the amount of displacement (amount of movement) of the light-converging point of laser light L from the surface (entrance face for laser light L) of the material to be cut in the optical axis direction of laser light L is determined so as to position the light-converging point of laser light L within the material to be cut according to the result of measurement (S 207 ). For embodiment, in conformity to the thickness and refractive index of the material to be cut, the amount of displacement (amount of movement) of the light-converging point of laser light L is set to ½ of the thickness of the material to be cut.
[0307] As shown in FIG. 22 , due to the difference between the refractive index in the atmosphere (e.g., air) surrounding the material to be cut and the refractive index of the material to be cut, the actual position of the light-converging point P of laser light is located deeper than the position of the light-converging point Q of laser light L converged by the light-converging lens 105 from the surface of the material to be cut (piezoelectric device wafer 31 ). Namely, the relationship of “amount of movement of Z-axis stage 113 in the optical axis direction of laser light L×refractive index of the material to be cut=actual amount of movement of light-converging point of laser light L” holds in the air. The amount of displacement (amount of movement) of the light-converging point of laser light L is set in view of the above-mentioned relationship (between the thickness and refractive index of the material to be cut). Thereafter, the material to be cut held by the wafer sheet 33 is mounted on the mounting table 107 placed on the X-Y-Z-axis stage (constituted by the X-axis stage 109 , Y-axis stage 111 , and Z-axis stage 113 in this embodiment) (S 209 ). After the mounting of the material to be cut is completed, light is emitted from the observation light source 117 , so as to irradiate the material to be cut with thus emitted light. Then, according to the result of imaging at the image pickup device 121 , focus adjustment is carried out by moving the Z-axis stage 113 so as to position the light-converging point of laser light L onto the surface of the material to be cut (S 211 ). Here, the surface observation image of piezoelectric device wafer 31 obtained by the observation light source 117 is captured by the image pickup device 121 , whereas the imaging data processor 125 determines the moving position of the Z-axis stage 113 according to the result of imaging such that the light emitted from the observation light source 117 forms a focal point on the surface of the material to be cut, and outputs thus determined position to the stage controller 115 . According to an output signal from the imaging data processor 125 , the stage controller 115 controls the Z-axis stage 113 such that the moving position of the Z-axis stage 113 is located at a position for making the light emitted from the observation light source 117 form a focal point on the material to be cut, i.e., for positioning the focal point of laser light L onto the surface of the material to be cut.
[0308] After the focus adjustment of light emitted from the observation light source 117 is completed, the light-converging point of laser light L is moved to a light-converging point corresponding to the thickness and refractive index of the material to be cut (S 213 ). Here, the overall controller 127 sends an output signal to the stage controller 115 so as to move the Z-axis stage 113 in the optical axis direction of laser light L by the amount of displacement of the light-converging point of laser light determined in conformity to the thickness and refractive index of the material to be cut, whereby the stage controller 115 having received the output signal regulates the moving position of the Z-axis stage 113 . As mentioned above, the placement of the light-converging point of laser light L within the material to be cut is completed by moving the Z-axis stage 113 in the optical axis direction of laser light L by the amount of displacement of the light-converging point of laser light L determined in conformity to the thickness and refractive index of the material to be cut (S 215 ).
[0309] After the placement of the light-converging point of laser light L within the material to be cut is completed, the material to be cut is irradiated with laser light L, and the X-axis stage 109 and the Y-axis stage 111 are moved inconformity to a desirable cutting pattern (S 217 ). As shown in FIG. 22 , the laser light L emitted from the laser light source 101 is converged by the light-converging lens 105 such that the light-converging point P is positioned within the piezoelectric device wafer 31 facing a predetermined gap (80 μm as mentioned above) formed between adjacent circuit sections 39 . The above-mentioned desirable cutting pattern is set such that the gap formed between the adjacent circuit sections 39 in order to separate a plurality of piezoelectric device chips 37 from the piezoelectric device wafer 31 is irradiated with the laser light L, whereas the laser light L is irradiated while the state of irradiation of laser light L is seen through the monitor 129 .
[0310] Here, as shown in FIG. 22 , the laser light L irradiating the material to be cut is converged by the light-converging lens 105 by an angle at which the circuit sections 39 formed on the surface of the piezoelectric device wafer 31 (the surface on which the laser light L is incident) are not irradiated with the laser light L. Converging the laser light L by an angle at which the circuit sections 39 are not irradiated with the laser light L can prevent the laser light L from entering the circuit sections 39 and protect the circuit sections 39 against the laser light L.
[0311] When the laser light L emitted from the laser light source 101 is converged such that the light-converging point P is positioned within the piezoelectric device wafer 31 while the energy density of laser light L at the light-converging point P exceeds a threshold of optical damage or optical dielectric breakdown, minute crack regions 9 are formed only at the light-converging point P within the piezoelectric device wafer 31 acting as a material to be cut and its vicinity. Here, the surface and rear face of the material to be cut (piezoelectric device wafer 31 ) will not be damaged.
[0312] Now, with reference to FIGS. 23 to 27 , the forming of cracks by moving the light-converging point of laser light L will be explained. The material to be cut 32 (light-transmitting material) having a substantially rectangular parallelepiped form shown in FIG. 23 is irradiated with laser light L such that the light-converging point of laser light L is positioned within the material to be cut 32 , whereby minute crack regions 9 are formed only at the light-converging point within the material to be cut 32 and its vicinity as shown in FIGS. 24 and 25 . The scanning of laser light L or movement of the material to be cut 32 is regulated so as to move the light-converging point of laser light L in the longitudinal direction D of material to be cut 32 intersecting the optical axis of laser light L.
[0313] Since the laser light L is emitted from the laser light source 101 in a pulsating manner, a plurality of crack regions 9 are formed with a gap therebetween corresponding to the scanning speed of laser light L or the moving speed of the material to be cut 32 along the longitudinal direction D of the material to be cut 32 when the laser light L is scanned or the material to be cut 32 is moved. The scanning speed of laser light L or the moving speed of material to be cut 32 may be slowed down, so as to shorten the gap between the crack regions 9 , thereby increasing the number of thus formed crack regions 9 as shown in FIG. 26 . The scanning speed of laser light L or the moving speed of material to be cut may further be slowed down, so that the crack region 9 is continuously formed in the scanning direction of laser light L or the moving direction of material to be cut 32 , i.e., the moving direction of the light-converging point of laser light L as shown in FIG. 27 . Adjustment of the gap between the crack regions 9 (number of crack regions 9 to be formed) can also be realized by changing the relationship between the repetition frequency of laser light L and the moving speed of the material to be cut 32 (X-axis stage or Y-axis stage). Also, throughput can be improved when the repetition frequency of laser light L and the moving speed of material to be cut 32 are increased.
[0314] Once the crack regions 9 are formed along the above-mentioned desirable cutting pattern (S 219 ), a stress is generated due to physical external force application, environmental changes, and the like within the material to be cut, the part formed with the crack regions 9 in particular, so as to grow the crack regions 9 formed only within the material to be cut (the light-converging point and its vicinity), thereby cutting the material to be cut at a position formed with the crack regions 9 (S 221 ).
[0315] With reference to FIGS. 28 to 32 , the cutting of the material to be cut upon physical external force application will be explained. First, the material to be cut (piezoelectric device wafer 31 ) formed with the crack regions 9 along the desirable cutting pattern is placed in a cutting apparatus while in a state held by a wafer sheet 33 grasped by the sample holder 35 . The cutting apparatus has a suction chuck 34 , which will be explained later, a suction pump (not depicted) connected to the suction chuck 34 , a pressure needle 36 (pressing member), pressure needle driving means (not depicted) for moving the pressure needle 36 , and the like. Usable as the pressure needle driving means is an actuator of electric, hydraulic, or other types. FIGS. 28 to 32 do not depict the circuit sections 39 .
[0316] Once the piezoelectric device wafer 31 is placed in the cutting apparatus, the suction chuck 34 approaches the position corresponding to the piezoelectric device chip 37 to be isolated as shown in FIG. 28 . A suction pump apparatus is actuated while in a state where the suction chuck 34 is located closer to or abuts against the piezoelectric device chip 37 to be isolated, whereby the suction chuck 34 attracts the piezoelectric device chip 37 (piezoelectric device wafer 31 ) to be isolated as shown in FIG. 29 . Once the suction chuck 34 attracts the piezoelectric device chip 37 (piezoelectric device wafer 31 ) to be isolated, the pressure needle 36 is moved to the position corresponding to the piezoelectric device chip 37 to be isolated from the rear face of wafer sheet 33 (rear face of the surface held with the piezoelectric device wafer 31 ) as shown in FIG. 30 .
[0317] When the pressure needle 36 is further moved after abutting against the rear face of the wafer sheet 33 , the wafer sheet 33 deforms, while the pressure needle 36 applies a stress to the piezo electric device wafer 31 from the outside, whereby a stress is generated in the wafer part formed with the crack regions 9 , which grows the crack regions 9 . When the crack regions 9 grow to the surface and rear face of the piezoelectric device wafer 31 , the piezoelectric device wafer 31 is cut at an end part of the piezoelectric device chip 37 to be isolated as shown in FIG. 31 , whereby the piezoelectric device chip 37 is isolated from the piezoelectric device wafer 31 . The wafer sheet 33 has an adhesiveness as mentioned above, thereby being able to prevent cut and separated piezoelectric device chips 37 from flying away.
[0318] Once the piezoelectric device chip 37 is separated from the piezoelectric device wafer 31 , the suction chuck 34 and pressure needle 36 are moved away from the wafer sheet 33 . When the suction chuck 34 and pressure needle 36 are moved, the isolated piezoelectric device chip 37 is released from the wafer sheet 33 as shown in FIG. 32 , since the former is attracted to the suction chuck 34 . Here, an ion air blow apparatus, which is not depicted, is used for sending an ion air in the direction of arrows B in FIG. 32 , whereby the piezoelectric device chip 37 isolated and attracted to the suction chuck 34 , and the piezoelectric device wafer 31 (surface) held by the wafer sheet 32 are cleaned with the ion air. Here, a suction apparatus may be provided in place of the ion air cleaning, such that the cut and separated piezoelectric device chips 37 and piezoelectric device wafer 31 are cleaned as dust and the like are aspirated. Known as a method of cutting the material to be cut due to environmental changes is one imparting a temperature change to the material to be cut having the crack regions 9 only therewithin. When a temperature change is imparted to the material to be cut as such, a thermal distortion can occur in the material part formed with the crack regions 9 , so that the crack regions grow, whereby the material to be cut can be cut.
[0319] Thus, in the second embodiment, the light-converging lens 105 converges the laser light L emitted from the laser light source 101 such that its light-converging point is positioned within the light-transmitting material (piezoelectric device wafer 31 ), whereby the energy density of laser light at the light-converging point exceeds the threshold of optical damage or optical dielectric breakdown, which forms the minute cracks 9 only at the light-converging point within the light-transmitting material and its vicinity. Since the light-transmitting material is cut at the positions of thus formed crack regions 9 , the amount of dust emission is very small, whereby the possibility of dicing damages, chipping, cracks on the material surface, and the like occurring also becomes very low. Since the light-transmitting material is cut along the crack regions 9 formed by the optical damages or optical dielectric breakdown of the light-transmitting material, the directional stability of cutting improves, so that cutting direction can be controlled easily. Also, the dicing width can be made smaller than that attained in the dicing with a diamond cutter, whereby the number of light-transmitting materials cut out from one light-transmitting material can be increased. As a result of these, the second embodiment can cut the light-transmitting material quite easily and appropriately.
[0320] Also, a stress is generated within the material to be cut due to physical external force application, environmental changes, and the like, so as to grow the formed crack regions 9 to cut the light-transmitting material (piezoelectric device wafer 31 ), whereby the light-transmitting material can reliably be cut at the positions of formed crack regions 9 .
[0321] Also, the pressure needle 36 is used for applying a stress to the light-transmitting material (piezoelectric device wafer 31 ), so as to grow the formed crack regions 9 to cut the light-transmitting material (piezoelectric device wafer 31 ), whereby the light-transmitting material can further reliably be cut at the positions of formed crack regions 9 .
[0322] When the piezoelectric device wafer 31 (light-transmitting material) formed with a plurality of circuit sections 39 is cut and separated into individual piezoelectric device chips 37 , the light-converging lens 105 converges the laser light L such that the light-converging point is positioned within the wafer part facing the gap formed between adjacent circuit sections 39 , and forms the crack regions 9 , whereby the piezoelectric device wafer 31 can reliably be cut at the position of the gap formed between adjacent circuit sections 39 .
[0323] When the light-transmitting material (piezoelectric device wafer 31 ) is moved or laser light L is scanned so as to move the light-converging point in a direction intersecting the optical axis of laser light L, e.g., a direction orthogonal thereto, the crack region 9 is continuously formed along the moving direction of the light-converging point, so that the directional stability of cutting further improves, which makes it possible to control the cutting direction more easily.
[0324] Also, in the second embodiment, dust-emitting powders hardly exist, so that no lubricating/cleaning water for preventing the dust-emitting powders from flying away is necessary, whereby dry processing can be realized in the cutting step.
[0325] In the second embodiment, since the forming of a modified part (crack region 9 ) is realized by non-contact processing with the laser light L, problems of durability of blades, their replacement frequency, and the like in the dicing caused by diamond cutters will not occur. Also, since the forming of a modified part (crack region 9 ) is realized by non-contact processing with the laser light L, the second embodiment can cut the light-transmitting material along a cutting pattern which cuts out the light-transmitting material without completely cutting the same. The present invention is not limited to the above-mentioned second embodiment. For embodiment, the light-transmitting material may be a semiconductor wafer, a glass substrate, or the like without being restricted to the piezoelectric device wafer 31 . Also, the laser light source 101 can appropriately be selected in conformity to an optical absorption characteristic of the light-transmitting material to be cut. Though the minute regions 9 are formed as a modified part upon irradiation with the laser light L in the second embodiment, it is not restrictive. For embodiment, using an ultra short pulse laser light source (e.g., femto second (fs) laser) can form a modified part caused by a refractive index change (higher refractive index), thus being able to cut the light-transmitting material without generating the crack regions 9 by utilizing such a mechanical characteristic change.
[0326] Though the focus adjustment of laser light L is carried out by moving the Z-axis stage 113 in the laser processing apparatus 100 , it may be effected by moving the light-converging lens 105 in the optical axis direction of laser light L without being restricted thereto.
[0327] Though the X-axis stage 109 and Y-axis stage 111 are moved in conformity to a desirable cutting pattern in the laser processing apparatus 100 , it is not restrictive, whereby the laser light L may be scanned in conformity to a desirable cutting pattern.
[0328] Though the piezoelectric device wafer 31 is cut by the pressure needle 36 after being attracted to the suction chuck 34 , it is not restrictive, whereby the piezoelectric device wafer 31 may be cut by the pressure needle 36 , and then the cut and isolated piezoelectric device chip 37 may be attracted to the suction chuck 34 . Here, when the piezoelectric device wafer 31 is cut by the pressure needle 36 after the piezoelectric device wafer 31 is attracted to the suction chuck 34 , the surface of the cut and isolated piezoelectric device chip 37 is covered with the suction chuck 34 , which can prevent dust and the like from adhering to the surface of the piezoelectric device chip 37 .
[0329] Also, when an image pickup device 121 for infrared rays is used, focus adjustment can be carried out by utilizing reflected light of laser light L. In this case, it is necessary that a half mirror be used instead of the dichroic mirror 103 , while disposing an optical device between the half mirror and the laser light source 101 , which suppresses the return light to the laser light source 101 . Here, it is preferred that the output of laser light L emitted from the laser light source 101 at the time of focus adjustment be set to an energy level lower than that of the output for forming cracks, such that the laser light L for carrying out focus adjustment does not damage the material to be cut.
[0330] Characteristic features of the present invention will now be explained from the viewpoints of the second embodiment.
[0331] The method of cutting a light-transmitting material in accordance with an aspect of the present invention comprises a modified part forming step of converging laser light emitted from a laser light source such that its light-converging point is positioned within the light-transmitting material, so as to form a modified part only at the light-converging point within the light-transmitting material and its vicinity; and a cutting step of cutting the light-transmitting material at the position of thus formed modified part.
[0332] In the method of cutting a light-transmitting material in accordance with this aspect of the present invention, the laser light is converged such that the light-converging point of laser light is positioned within the light-transmitting material in the modified part forming step, whereby the modified part is formed only at the light-converging point within the light-transmitting material and its vicinity. In the cutting step, the light-transmitting material is cut at the position of thus formed modified part, so that the amount of dust emission is very small, whereby the possibility of dicing damages, chipping, cracks on the material surface, and the like occurring also becomes very low. Since the light-transmitting material is cut at the position of thus formed modified part, the directional stability of cutting improves, so that cutting direction can be controlled easily. Also, the dicing width can be made smaller than that attained in the dicing with a diamond cutter, whereby the number of light-transmitting materials cut out from one light-transmitting material can be increased. As a result of these, the present invention can cut the light-transmitting material quite easily and appropriately.
[0333] Also, in the method of cutting a light-transmitting material in accordance with this aspect of the present invention, dust-emitting powders hardly exist, so that no lubricating/cleaning water for preventing the dust-emitting powders from flying away is necessary, whereby dry processing can be realized in the cutting step.
[0334] In the method of cutting a light-transmitting material in accordance with this aspect of the present invention, since the forming of a modified part is realized by non-contact processing with laser light, problems of durability of blades, their replacement frequency, and the like in the dicing caused by diamond cutters will not occur. Also, since the forming of a modified part is realized by non-contact processing with the laser light, the method of cutting a light-transmitting material in accordance with this aspect of the present invention can cut the light-transmitting material along a cutting pattern which cuts out the light-transmitting material without completely cutting the same.
[0335] Preferably, the light-transmitting material is formed with a plurality of circuit sections, whereas laser light is converged such that the light-converging point is positioned within the light-transmitting material part facing the gap formed between adjacent circuit sections in the modified part forming step, so as to form the modified part. With such a configuration, the light-transmitting material can reliably be cut at the position of the gap formed between adjacent circuit sections.
[0336] When irradiating the light-transmitting material with laser light in the modified part forming step, it is preferred that the laser light be converged by an angle at which the circuit sections are not irradiated with the laser light. Converging the laser light by an angle at which the circuit sections are not irradiated with the laser light when irradiating the light-transmitting material with the laser light in the modified part forming step as such can prevent the laser light from entering the circuit sections and protect the circuit sections against the laser light.
[0337] Preferably, in the modified part forming step, the light-converging point is moved in a direction intersecting the optical axis of laser light, so as to form a modified part continuously along the moving direction of the light-converging point. When the light-converging point is moved in a direction intersecting the optical axis of laser light in the modified part forming step as such, so as to form the modified part continuously along the moving direction of the light-converging point, the directional stability of cutting further improves, which makes it further easier to control the cutting direction.
[0338] The method of cutting a light-transmitting material in accordance with an aspect of the present invention comprises a crack forming step of converging laser light emitted from a laser light source such that its light-converging point is positioned within the light-transmitting material, so as to form a crack only at the light-converging point within the light-transmitting material and its vicinity; and a cutting step of cutting the light-transmitting material at the position of thus formed crack.
[0339] In the method of cutting a light-transmitting material in accordance with this aspect of the present invention, laser light is converged such that the light-converging point of laser light is positioned within the light-transmitting material, so that the energy density of laser light at the light-converging point exceeds a threshold of optical damage or optical dielectric breakdown of the light-transmitting material, whereby a crack is formed only at the light-converging point within the light-transmitting material and its vicinity. In the cutting step, the light-transmitting material is cut at the position of thus formed crack, so that the amount of dust emission is very small, whereby the possibility of dicing damages, chipping, cracks on the material surface, and the like occurring also becomes very low. Since the light-transmitting material is cut at the position of the crack formed by an optical damage or optical dielectric breakdown, the directional stability of cutting improves, so that cutting direction can be controlled easily. Also, the dicing width can be made smaller than that attained in the dicing with a diamond cutter, whereby the number of light-transmitting materials cut out from one light-transmitting material can be increased. As a result of these, the present invention can cut the light-transmitting material quite easily and appropriately.
[0340] Also, in the method of cutting a light-transmitting material in accordance with this aspect of the present invention, dust-emitting powders hardly exist, so that no lubricating/cleaning water for preventing the dust-emitting powders from flying away is necessary, whereby dry processing can be realized in the cutting step.
[0341] In the method of cutting a light-transmitting material in accordance with this aspect of the present invention, since the forming of a crack is realized by non-contact processing with laser light, problems of durability of blades, their replacement frequency, and the like in the dicing caused by diamond cutters will not occur. Also, since the forming of a crack is realized by non-contact processing with the laser light, the method of cutting a light-transmitting material in accordance with this aspect of the present invention can cut the light-transmitting material along a cutting pattern which cuts out the light-transmitting material without completely cutting the same.
[0342] Preferably, in the cutting step, the light-transmitting material is cut by growing the formed crack. Cutting the light-transmitting material by growing the formed crack in the cutting step as such can reliably cut the light-transmitting material at the position of the formed crack.
[0343] Preferably, in the cutting step, a stress is applied to the light-transmitting material by using a pressing member, so as to grow a crack, thereby cutting the light-transmitting material. When a stress is applied to the light-transmitting material in the cutting step by using a pressing member as such, so as to grow a crack, thereby cutting the light-transmitting material, the light-transmitting material can further reliably be cut at the position of the crack.
[0344] The apparatus for cutting a light-transmitting material in accordance with an aspect of the present invention comprises a laser light source; holding means for holding the light-transmitting material; an optical device for converging the laser light emitted from the laser light source such that a light-converging point thereof is positioned within the light-transmitting material; and cutting means for cutting the light-transmitting material at the position of a modified part formed only at the light-converging point of laser light within the light-transmitting material and its vicinity.
[0345] In the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, the optical device converges laser light such that the light-converging point of laser light is positioned within the light-transmitting material, whereby a modified part is formed only at the light-converging point within the light-transmitting material and its vicinity. Then, the cutting means cuts the light-transmitting material at the position of the modified part formed only at the light-converging point within the light-transmitting material and its vicinity, whereby the light-transmitting material is reliably cut along thus formed modified part. As a consequence, the amount of dust emission is very small, whereas the possibility of dicing damages, chipping, cracks on the material surface, and the like occurring also becomes very low. Also, since the light-transmitting material is cut along the modified part, the directional stability of cutting improves, whereby the cutting direction can be controlled easily. Also, the dicing width can be made smaller than that attained in the dicing with a diamond cutter, whereby the number of light-transmitting materials cut out from one light-transmitting material can be increased. As a result of these, the present invention can cut the light-transmitting material quite easily and appropriately.
[0346] Also, in the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, dust-emitting powders hardly exist, so that no lubricating/cleaning water for preventing the dust-emitting powders from flying away is necessary, whereby dry processing can be realized in the cutting step.
[0347] In the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, since the modified part is formed by non-contact processing with laser light, problems of durability of blades, their replacement frequency, and the like in the dicing caused by diamond cutters will not occur as in the conventional techniques. Also, since the modified part is formed by non-contact processing with the laser light as mentioned above, the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention can cut the light-transmitting material along a cutting pattern which cuts out the light-transmitting material without completely cutting the same.
[0348] The apparatus for cutting a light-transmitting material in accordance with an aspect of the present invention comprises a laser light source; holding means for holding the light-transmitting material; an optical device for converging laser light emitted from the laser light source such that a light-converging point thereof is positioned within the light-transmitting material; and cutting means for cutting the light-transmitting material by growing a crack formed only at the light-converging point of laser light within the light-transmitting material and its vicinity.
[0349] In the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, the optical device converges laser light such that the light-converging point of laser light is positioned within the light-transmitting material, so that the energy density of laser light at the light-converging point exceeds a threshold of optical damage or optical dielectric breakdown of the light-transmitting material, whereby a crack is formed only at the light-converging point within the light-transmitting material and its vicinity. Then, the cutting means cuts the light-transmitting material by growing the crack formed only at the light-converging point within the light-transmitting material and its vicinity, whereby the light-transmitting material is reliably cut along the crack formed by an optical damage or optical dielectric breakdown of the light-transmitting material. As a consequence, the amount of dust emission is very small, whereas the possibility of dicing damages, chipping, cracks on the material surface, and the like occurring also becomes very low. Since the light-transmitting material is cut along the crack, the directional stability of cutting improves, so that cutting direction can be controlled easily. Also, the dicing width can be made smaller than that attained in the dicing with a diamond cutter, whereby the number of light-transmitting materials cut out from one light-transmitting material can be increased. As a result of these, the present invention can cut the light-transmitting material quite easily and appropriately.
[0350] Also, in the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, dust-emitting powders hardly exist, so that no lubricating/cleaning water for preventing the dust-emitting powders from flying away is necessary, whereby dry processing can be realized in the cutting step.
[0351] In the apparatus for cutting a light-transmitting material in accordance with this aspect of the present invention, since the crack is formed by non-contact processing with laser light, problems of durability of blades, their replacement frequency, and the like in the dicing caused by diamond cutters will not occur as in the conventional techniques. Also, since the crack is formed by non-contact processing with the laser light as mentioned above, the method of cutting a light-transmitting material in accordance with this aspect of the present invention can cut the light-transmitting material along a cutting pattern which cuts out the light-transmitting material without completely cutting the same.
[0352] Preferably, the cutting means has a pressing member for applying a stress to the light-transmitting material. When the cutting means has a pressing member for applying a stress to the light-transmitting material as such, a stress can be applied to the light-transmitting material by using the pressing member, so as to grow a crack, whereby the light-transmitting material can further reliably be cut at the position of the crack formed.
[0353] Preferably, the light-transmitting material is one whose surface is formed with a plurality of circuit sections, whereas the optical device converges the laser light such that the light-converging point is positioned within the light-transmitting material part facing the gap formed between adjacent circuit sections. With such a configuration, the light-transmitting material can reliably be cut at the position of the gap formed between adjacent circuit sections.
[0354] Preferably, the optical device converges laser light by an angle at which the circuit sections are not irradiated with the laser light. When the optical device converges the laser light by an angle at which the circuit sections are not irradiated with the laser light as such, it can prevent the laser light from entering the circuit sections and protect the circuit sections against the laser light.
[0355] Preferably, the apparatus further comprises light-converging point moving means for moving the light-converging point in a direction intersecting the optical axis of laser light. When the apparatus further comprises light-converging point moving means for moving the light-converging point in a direction intersecting the optical axis of laser light as such, a crack can continuously be formed along the moving direction of the light-converging point, so that the directional stability of cutting further improves, whereby the direction of cutting can be controlled further easily.
Third Embodiment
[0356] A third embodiment of the present invention will be explained. In the third embodiment and a fourth embodiment which will be explained later, an object to be processed is irradiated with laser light such that the direction of linear polarization of linearly polarized laser light extends along a line along which the object is intended to be cut in the object to be processed, whereby a modified region is formed in the object to be processed. As a consequence, in the modified spot formed with a single pulse of shot (i.e., a single pulse of laser irradiation), the size in the direction extending along the line along which the object is intended to be cut can be made relatively large when the laser light is pulse laser light. The inventor has confirmed it by an experiment. Conditions for the experiment are as follows:
(A) Object to be processed: Pyrex glass wafer (having a thickness of 700 μm and an outer diameter of 4 inches) (B) Laser
Light source: semiconductor laser pumping Nd:YAG laser Wavelength: 1064 nm Laser light spot cross-sectional area: 3.14×10 −8 cm 2 Oscillation mode: Q-switch pulse Repetition frequency: 100 kHz Pulse width: 30 ns Output: output<1 mJ/pulse Laser light quality: TEM 00 Polarization characteristic: linear polarization
(C) Light-converging lens
Magnification: ×50 NA: 0.55 Transmittance with respect to laser light wavelength: 60%
(D) Moving speed of a mounting table mounting the object to be processed: 100 mm/sec
[0373] Each of Samples 1, 2, which was an object to be processed, was exposed to a single pulse shot of pulse laser light while the light-converging point is located within the object to be processed, whereby a crack region caused by multiphoton absorption is formed within the object to be processed. Sample 1 was irradiated with linearly polarized pulse laser light, whereas Sample 2 was irradiated with circularly polarized pulse laser light.
[0374] FIG. 33 is a view showing a photograph of Sample 1 in plan, whereas FIG. 34 is a view showing a photograph of Sample 2 in plan. These planes are an entrance face 209 of pulse laser light. Letters LP and CP schematically indicate linear polarization and circular polarization, respectively. FIG. 35 is a view schematically showing a cross section of Sample 1 shown in FIG. 33 taken along the line XXXV-XXXV. FIG. 36 is a view schematically showing a cross section of Sample 1 shown in FIG. 34 taken along the line XXXVI-XXXVI. A crack spot 90 is formed within a glass wafer 211 which is the object to be processed.
[0375] In the case where pulse laser light is linearly polarized light, as shown in FIG. 35 , the size of crack spot 90 formed by a single pulse shot is relatively large in the direction aligning with the direction of linear polarization. This indicates that the forming of the crack spot 90 is accelerated in this direction. When the pulse laser light is circularly polarized light, by contrast, the size of the crack spot 90 formed by a single pulse shot will not become greater in any specific direction as shown in FIG. 36 . The size of the crack spot 90 in the direction yielding the maximum length is greater in Sample 1 than in Sample 2.
[0376] The fact that a crack region extending along a line along which the object is intended to be cut can be formed efficiently will be explained from these results of experiment. FIGS. 37 and 38 are plan views of crack regions each formed along a line along which the object is intended to be cut in an object to be processed. A number of crack spots 90 , each formed by a single pulse shot, are formed along a line 5 along which the object is intended to be cut, whereby a crack region 9 extending along the line 5 along which the object is intended to be cut is formed. FIG. 37 shows the crack region 9 formed upon irradiation with pulse laser light such that the direction of linear polarization of pulse laser light aligns with the line 5 along which the object is intended to be cut. The forming of crack spots 9 is accelerated along the direction of the line 5 along which the object is intended to be cut, whereby their size is relatively large in this direction. Therefore, the crack region 9 extending along the line 5 along which the object is intended to be cut can be formed by a smaller number of shots. On the other hand, FIG. 38 shows the crack region 9 formed upon irradiation with pulse laser light such that the direction of linear polarization of pulse laser light is orthogonal to the line 5 along which the object is intended to be cut. Since the size of crack spot 90 in the direction of the line 5 along which the object is intended to be cut is relatively small, the number of shots required for forming the crack region 9 becomes greater than that in the case of FIG. 37 . Therefore, the method of forming a crack region in accordance with this embodiment shown in FIG. 37 can form the crack region more efficiently than the method shown in FIG. 38 does.
[0377] Also, since pulse laser light is irradiated while the direction of linear polarization of pulse laser light is orthogonal to the line 5 along which the object is intended to be cut, the forming of the crack spot 90 formed at the shot is accelerated in the width direction of the line 5 along which the object is intended to be cut. Therefore, when the crack spot 90 extends in the width direction of the line 5 along which the object is intended to be cut too much, the object to be processed cannot precisely be cut along the line 5 along which the object is intended to be cut. By contrast, the crack spot 90 formed at the shot does not extend much in directions other than the direction aligning with the line 5 along which the object is intended to be cut in the method in accordance with this embodiment shown in FIG. 37 , whereby the object to be processed can be cut precisely.
[0378] Though making the size in a predetermined direction relatively large among the sizes of a modified region has been explained in the case of linear polarization, the same holds in elliptical polarization as well. Namely, as shown in FIG. 39 , the forming of the crack spot 90 is accelerated in the direction of major axis b of an ellipse representing elliptical polarization EP of laser light, whereby the crack spot 90 having a relatively large size along this direction can be formed. Hence, when a crack region is formed such that the major axis of an ellipse indicative of the elliptical polarization of laser elliptically polarized with an ellipticity of other than 1 aligns with a line along which the object is intended to be cut in the object to be processed, effects similar to those in the case of linear polarization occur. Here, the ellipticity is half the length of minor axis a/half the length of major axis b. As the ellipticity is smaller, the size of the crack spot 90 along the direction of major axis b becomes greater. Linearly polarized light is elliptically polarized light with an ellipticity of zero. Circularly polarized light is obtained when the ellipticity is 1, which cannot make the size of the crack region relatively large in a predetermined direction. Therefore, this embodiment does not encompass the case where the ellipticity is 1.
[0379] Though making the size in a predetermined direction relatively large among the sizes of a modified region has been explained in the case of a crack region, the same holds in molten processed regions and refractive index change regions as well. Also, though pulse laser light is explained, the same holds in continuous wave laser light as well. The foregoing also hold in a fourth embodiment which will be explained later.
[0380] The laser processing apparatus in accordance with the third embodiment of the present invention will now be explained. FIG. 40 is a schematic diagram of this laser processing apparatus. The laser processing apparatus 200 will be explained mainly in terms of its differences from the laser processing apparatus 100 in accordance with the first embodiment shown in FIG. 14 . The laser processing apparatus 200 comprises an ellipticity regulator 201 for adjusting the ellipticity of polarization of laser light L emitted from a laser light source 101 , and a 90° rotation regulator 203 for adjusting the rotation of polarization of the laser light L emitted from the ellipticity regulator 201 by about 90°.
[0381] The ellipticity regulator 201 includes a quarter wave plate 207 shown in FIG. 41 . The quarter wave plate 207 can adjust the ellipticity of elliptically polarized light by changing the angle of direction θ. Namely, when light with linear polarization LP is made incident on the quarter wave plate 207 , the transmitted light attains elliptical polarization EP with a predetermined ellipticity. The angle of direction is an angle formed between the major axis of the ellipse and the X axis. As mentioned above, a number other than 1 is employed as the ellipticity in this embodiment. The ellipticity regulator 201 can make the polarization of laser light L become elliptically polarized light EP having a desirable ellipticity. The ellipticity is adjusted in view of the thickness and material of the object to be processed 1 , and the like.
[0382] When irradiating the object to be processed 1 with laser light L having linear polarization LP, the laser light L emitted from the laser light source 101 is linearly polarized light LP, whereby the ellipticity regulator 201 adjusts the angle of direction θ of the quarter wave plate 207 such that the laser light L passes through the quarter wave plate while being the linearly polarized light LP. Also, the laser light source 101 emits linearly polarized laser light L, whereby the ellipticity regulator 201 is unnecessary when only laser light of linear polarization LP is utilized for irradiating the object to be processed with laser.
[0383] The 90° rotation regulator 203 includes a half wave plate 205 as shown in FIG. 42 . The half wave plate 205 is a wavelength plate for making polarization orthogonal to linearly polarized incident light. Namely, when linearly polarized light LP 1 with an angle of direction of 45° is incident on the half wave plate 205 , for embodiment, transmitted light becomes linearly polarized light LP 2 rotated by 90° with respect to the incident light LP 1 . When rotating the polarization of laser light L emitted from the ellipticity regulator 201 by 90°, the 90° rotation regulator 203 operates so as to place the half wave plate 205 onto the optical axis of laser light L. When not rotating the polarization of laser light L emitted from the ellipticity regulator 201 , the 90° rotation regulator 203 operates so as to place the half wave plate 205 outside the optical path of laser light L (i.e., at a site where the laser light L does not pass through the half wave plate 205 ).
[0384] The dichroic mirror 103 is disposed such that the laser light L whose rotation of polarization is regulated by 90° or not by the 90° rotation regulator 203 is incident thereon and that the direction of optical axis of laser light L is changed by 90°. The laser processing apparatus 200 comprises a θ-axis stage 213 for rotating the X-Y plane of the mounting table 107 about the thickness direction of the object to be processed 1 . The stage controller 115 regulates not only the movement of stages 109 , 111 , 113 , but also the movement of stage 213 .
[0385] With reference to FIGS. 40 and 43 , the laser processing method in accordance with the third embodiment of the present invention will now be explained. FIG. 43 is a flowchart for explaining this laser processing method. The object to be processed 1 is a silicon wafer. Steps S 101 to S 111 are the same as those of the first embodiment shown in FIG. 15 .
[0386] The ellipticity regulator 201 adjusts the ellipticity of laser light L having linear polarization LP emitted from the laser light source 101 (S 121 ). The laser light L having elliptical polarization EP with a desirable ellipticity can be obtained when the angle of direction θ of the quarter wave plate is changed in the ellipticity regulator 201 .
[0387] First, for processing the object to be processed 1 along the Y-axis direction, the major axis of an ellipse indicative of the elliptical polarization EP of laser light L is adjusted so as to coincide with the direction of the line 5 along which the object is intended to be cut extending in the Y-axis direction of the object to be processed 1 (S 123 ). This is achieved by rotating the θ-axis stage 213 . Therefore, the θ-axis stage 213 functions as major axis adjusting means or linear polarization adjusting means.
[0388] For processing the object 1 along the Y-axis direction, the 90° rotation regulator 203 carries out adjustment which does not rotate the polarization of laser light L (S 125 ). Namely, it operates so as to place the half wave plate to the outside of the optical path of laser light L.
[0389] The laser light source 101 generates laser light L, whereas the line 5 along which the object is intended to be cut extending in the Y-axis direction in the surface 3 of the object to be processed 1 is irradiated with the laser light L. FIG. 44 is a plan view of the object 1 . The object 1 is irradiated with the laser light L such that the major axis indicative of the ellipse of elliptical polarization EP of laser light extends along the rightmost line 5 along which the object is intended to be cut in the object 1 . Since the light-converging point P of laser light L is positioned within the object 1 , molten processed regions are formed only within the object 1 . The Y-axis stage 111 is moved along the line 5 along which the object is intended to be cut, so as to form a molten processed region within the object to be processed 1 along the line 5 along which the object is intended to be cut.
[0390] Then, the X-axis stage 109 is moved, so as to irradiate the neighboring line 5 along which the object is intended to be cut with laser light L, and a molten processed region is formed within the object 1 along the neighboring line 5 along which the object is intended to be cut in a manner similar to that mentioned above. By repeating this, a molten processed region is formed within the object 1 along the lines along which the object is intended to be cut successively from the right side (S 127 ). FIG. 45 shows the case where the object 1 is irradiated with the laser light L having linear polarization. Namely, the object 1 is irradiated with laser light such that the direction of linear polarization LP of laser light extends along the line 5 along which the object is intended to be cut in the object 1 .
[0391] Next, the 90° rotation regulator 203 operates so as to place the half wave plate 205 ( FIG. 42 ) onto the optical axis of laser light L. This carries out adjustment for rotating the polarization of laser light emitted from the ellipticity regulator 219 by 90° (S 219 ).
[0392] Subsequently, the laser light 101 generates laser light L, whereas the line along which the object is intended to be cut extending in the X-axis direction of the surface 3 of the object 1 is irradiated with the laser light L. FIG. 46 is a plan view of the object 1 . The object 1 is irradiated with the laser light L such that the direction of the major axis of an ellipse indicative of the elliptical polarization EP of laser light L extends along the lowest line 5 along which the object is intended to be cut extending in the X-axis direction of the object 1 . Since the light-converging point P of laser light L is positioned within the object 1 , molten processed regions are formed only within the object 1 . The X-axis stage 109 is moved along the line 5 along which the object is intended to be cut, so as to form a molten processed region within the object 1 extending along the line 5 along which the object is intended to be cut.
[0393] Then, the Y-axis stage is moved, such that the immediately upper line 5 along which the object is intended to be cut is irradiated with the laser light L, whereby a molten processed region is formed within the object 1 along the line 5 along which the object is intended to be cut in a manner similar to that mentioned above. By repeating this, respective molten processed regions are formed within the object 1 along the individual lines along which the object is intended to be cut successively from the lower side (S 131 ). FIG. 47 shows the case where the object 1 is irradiated with the laser light L having linear polarization LP.
[0394] Then, the object 1 is bent along the lines along which the object is intended to be cut 5 , whereby the object 1 is cut (S 133 ). This divides the object 1 into silicon chips.
[0395] Effects of the third embodiment will be explained. According to the third embodiment, the object 1 is irradiated with pulse laser light L such that the direction of the major axis of an ellipse indicative of the elliptical polarization EP of pulse laser light L extends along the line 5 along which the object is intended to be cut as shown in FIGS. 44 and 46 . As a consequence, the size of crack spots in the direction of line 5 along which the object is intended to be cut becomes relatively large, whereby crack regions extending along lines along which the object is intended to be cut can be formed by a smaller number of shots. The third embodiment can efficiently form crack regions as such, thus being able to improve the processing speed of the object 1 . Also, the crack spot formed at the shot does not extend in directions other than the direction aligning with the line 5 along which the object is intended to be cut, whereby the object 1 can be cut precisely along the line 5 along which the object is intended to be cut. These results are similar to those of the fourth embodiment which will be explained later.
Fourth Embodiment
[0396] The fourth embodiment of the present invention will be explained mainly in terms of its differences from the third embodiment. FIG. 48 is a schematic diagram of this laser processing apparatus 300 . Among the constituents of the laser processing apparatus 300 , those identical to constituents of the laser processing apparatus 200 in accordance with the third embodiment shown in FIG. 40 will be referred to with numerals identical thereto without repeating their overlapping explanations.
[0397] The laser processing apparatus 300 is not equipped with the 90° rotation regulator 203 of the third embodiment. A θ-axis stage 213 can rotate the X-Y plane of a mounting table 107 about the thickness direction of the object to be processed 1 . This makes the polarization of laser light L emitted from the ellipticity regulator 201 relatively rotate by 90°.
[0398] The laser processing method in accordance with the fourth embodiment of the present invention will be explained. Operations of step S 101 to step S 123 in the laser processing method in accordance with the third embodiment shown in FIG. 43 are carried out in the fourth embodiment as well. The operation of subsequent step S 125 is not carried out, since the fourth embodiment is not equipped with the 90° rotation regulator 203 .
[0399] After step S 123 , the operation of step S 127 is carried out. The operations carried out so far process the object 1 as shown in FIG. 44 in a manner similar to that in the third embodiment. Thereafter, the stage controller 115 regulates the θ-axis stage 213 so as to rotate it by 90°. The rotation of the θ-axis stage 213 rotates the object 1 by 90° in the X-Y plane. Consequently, as shown in FIG. 49 , the major axis of elliptical polarization EP can be caused to align with a line along which the object is intended to be cut intersecting the line 5 along which the object is intended to be cut having already completed the modified region forming step.
[0400] Then, like step S 127 , the object 1 is irradiated with the laser light, whereby molten processed regions are formed within the object to be processed 1 along line 5 along which the object is intended to be cut successively from the right side. Finally, as with step S 133 , the object is cut, whereby the object 1 is divided into silicon chips.
[0401] The third and fourth embodiments of the present invention explained in the foregoing relate to the forming of modified regions by multiphoton absorption. However, the present invention may cut the object to be processed by irradiating it with laser light while locating its light-converging point within the object so as to make the major axis direction of an ellipse indicative of elliptical polarization extend along a line along which the object is intended to be cut in the object without forming modified regions caused by multiphoton absorption. This can also cut the object along the line along which the object is intended to be cut efficiently.
Fifth Embodiment
[0402] In a fifth embodiment of the present invention and sixth and seventh embodiments thereof, which will be explained later, sizes of modified spots are controlled by regulating the magnitude of power of pulse laser light and the size of numerical aperture of an optical system including a light-converging lens. The modified spot refers to a modified part formed by a single pulse shot of pulse laser light (i.e., one pulse laser irradiation), whereas an assembly of modified spots forms a modified region. The necessity to control the sizes of modified spots will be explained with respect to crack spots by way of embodiment.
[0403] When a crack spot is too large, the accuracy of cutting an object to be cut along a line along which the object is intended to be cut decreases, and the flatness of the cross section deteriorates. This will be explained with reference to FIGS. 50 to 55 . FIG. 50 is a plan view of an object to be processed 1 in the case where crack spots are formed relatively large by using the laser processing method in accordance with this embodiment. FIG. 51 is a sectional view taken along LI-LI on the line 5 along which the object is intended to be cut in FIG. 50 . FIGS. 52 , 53 , and 54 are sectional views taken along lines LII-LII, LIII-LIII, and LIV-LIV orthogonal to the line 5 along which the object is intended to be cut in FIG. 50 , respectively. As can be seen from these drawings, the deviation in sizes of crack spots 9 becomes greater when the crack spots 90 are too large. Therefore, as shown in FIG. 55 , the accuracy of cutting the object 1 along the line 5 along which the object is intended to be cut becomes lower. Also, irregularities of cross sections 43 in the object 1 become so large that the flatness of the cross section 43 deteriorates. When crack spots 90 are formed relatively small (e.g., 20 μm or less) by using the laser processing apparatus in accordance with this embodiment, by contrast, crack spots 90 can be formed uniformly and can be restrained from widening in directions deviating from that of the line along which the object is intended to be cut as shown in FIG. 56 . Therefore, as shown in FIG. 57 , the accuracy of cutting the object 1 along the line 5 along which the object is intended to be cut and the flatness of cross sections 43 can be improved as shown in FIG. 57 .
[0404] When crack spots are too large as such, precise cutting along a line along which the object is intended to be cut and cutting for yielding a flat cross-section cannot be carried out. If crack spots are extremely small with respect to an object to be processed having a large thickness, however, the object will be hard to cut.
[0405] The fact that this embodiment can control sizes of crack spots will be explained. As shown in FIG. 7 , when the peak power density is the same, the size of a crack spot in the case where the light-converging lens has a magnification of ×10 and an NA of 0.8 is smaller than that of a crack spot in the case where the light-converging lens has a magnification of ×50 and an NA of 0.55. The peak power density is proportional to the energy of laser light per pulse, i.e., the power of pulse laser light, as explained above, whereby the same peak power density means the same laser light power. When the laser light power is the same while the beam spot cross-sectional area is the same, sizes of crack spots can be regulated so as to become smaller (greater) as the numerical aperture of a light-converging lens is greater (smaller).
[0406] Also, even when the numerical aperture of the light-converging lens is the same, sizes of crack spots can be regulated so as to become smaller and larger when the laser light power (peak power density) is made lower and higher, respectively.
[0407] Therefore, as can be seen from the graph shown in FIG. 7 , sizes of crack spots can be regulated so as to become smaller when the numerical aperture of a light-converging lens is made greater or the laser light power is made lower. On the contrary, sizes of crack spots can be regulated so as to become greater when the numerical aperture of a light-converging lens is made smaller or when the laser light power is made higher.
[0408] The crack spot size control will further be explained with reference to the drawings. The embodiment shown in FIG. 58 is a sectional view of an object to be processed 1 within which pulse laser light L is converged by use of a light-converging lens having a predetermined numerical aperture. Regions 41 are those having yielded an electric field intensity at a threshold for causing multiphoton absorption or higher by this laser irradiation. FIG. 59 is a sectional view of a crack spot 90 formed due to the multiphoton absorption caused by irradiation with the laser light L. On the other hand, the embodiment shown in FIG. 60 is a sectional view of an object to be processed 1 within which pulse laser light L is converged by use of a light-converging lens having a numerical aperture greater than that in the embodiment shown in FIG. 58 . FIG. 61 is a sectional view of a crack spot 90 formed due to the multiphoton absorption caused by irradiation with the laser light L. The height h of crack spot 90 depends on the size of regions 41 in the thickness direction of the object 1 , whereas the width w of crack spot 90 depends on the size of regions 41 in a direction orthogonal to the thickness direction of the object 1 . Namely, when these sizes of regions 41 are made smaller and greater, the height h and width w of crack spot 90 can be made smaller and greater, respectively. As can be seen when FIGS. 59 and 61 are compared with each other, in the case where the laser light power is the same, the sizes of height h and width w of crack spot 90 can be regulated so as to become smaller (greater) when the numerical aperture of a light-converging lens is made greater (smaller).
[0409] The embodiment shown in FIG. 62 is a sectional view of an object to be processed 1 within which pulse laser light L having a power lower than that in the embodiment shown in FIG. 58 is converged. In the embodiment shown in FIG. 62 , since the laser light power is made lower, the area of regions 41 is smaller than that of regions 41 shown in FIG. 58 . FIG. 63 is a sectional view of a crack spot 90 formed due to the multiphoton absorption caused by irradiation with the laser light L. As can be seen when FIGS. 59 and 63 are compared with each other, in the case where the numerical aperture of the light-converging lens is the same, the sizes of height h and width w of crack spot 90 can be regulated so as to become smaller (greater) when the laser light power is made lower (higher).
[0410] The embodiment shown in FIG. 64 is a sectional view of an object to be processed 1 within which pulse laser light L having a power lower than that in the embodiment shown in FIG. 60 is converged. FIG. 65 is a sectional view of a crack spot 90 formed due to the multiphoton absorption caused by irradiation with the laser light L. As can be seen when FIGS. 59 and 65 are compared with each other, the sizes of height h and width w of crack spot 90 can be regulated so as to become smaller (greater) when the numerical aperture of the light-converging lens is made greater (smaller) while the laser light power is made lower (higher).
[0411] Meanwhile, the regions 41 indicative of those yielding an electric field intensity at a threshold for electric field intensity capable of forming a crack spot or higher are restricted to the light-converging point P and its vicinity due to the following reason: Since a laser light source with a high beam quality is utilized, this embodiment achieves a high convergence of laser light and can converge light up to about the wavelength of laser light. As a consequence, the beam profile of this laser light attains a Gaussian distribution, whereby the electric field intensity is distributed so as to become the highest at the center of the beam and gradually lowers as the distance from the center increases. The laser light is basically converged in the state of a Gaussian distribution in the process of being converged by a light-converging lens in practice as well. Therefore, the regions 41 are restricted to the light-converging point P and its vicinity.
[0412] As in the foregoing, this embodiment can control sizes of crack spots. Sizes of crack spots are determined in view of a requirement for a degree of precise cutting, a requirement for a degree of flatness in cross sections, and the magnitude of thickness of the object to be processed. Sizes of crack spots can be determined in view of the material of an object to be processed as well. This embodiment can control sizes of modified spots, thus making it possible to carry out precise cutting along a line along which the object is intended to be cut and yield a favorable flatness in cross sections by making modified spots smaller for objects to be processed having a relatively small thickness. Also, by making modified spots greater, it enables cutting of objects to be processed having a relatively large thickness.
[0413] There are cases where an object to be processed has respective directions easy and hard to cut due to the crystal orientation of the object, for embodiment. When cutting such an object, the size of crack spots 90 formed in the easy-to-cut direction is made greater as shown in FIGS. 56 and 57 , for embodiment. When the direction of a line along which the object is intended to be cut orthogonal to the line 5 along which the object is intended to be cut is a hard-to-cut direction, on the other hand, the size of crack spots 90 formed in this direction is made greater as shown in FIGS. 57 and 66 . Here, FIG. 66 is a sectional view of the object 1 shown in FIG. 57 taken along LXVI-LXVI. Hence, a flat cross section can be obtained in the easy-to-cut direction, while cutting is possible in the hard-to-cut direction as well.
[0414] Though the fact that sizes of modified spots are controllable has been explained in the case of crack spots, the same holds in melting spots and refractive index change spots. For embodiment, the power of pulse laser light can be expressed by energy per pulse (J), or average output (W) which is a value obtained by multiplying the energy per pulse by the frequency of laser light. The foregoing holds in sixth and seventh embodiments which will be explained later.
[0415] The laser processing apparatus in accordance with the fifth embodiment of the present invention will be explained. FIG. 67 is a schematic diagram of this laser processing apparatus 400 . The laser processing apparatus 400 will be explained mainly in terms of its differences from the laser processing apparatus 100 in accordance with the first embodiment shown in FIG. 14 .
[0416] The laser processing apparatus 400 comprises a power regulator 401 for adjusting the power of laser light L emitted from a laser light source 101 . The power regulator 401 comprises, for embodiment, a plurality of ND (neutral density) filters, and a mechanism for moving the individual ND filters to positions perpendicular to the optical axis of the laser light L and to the outside of the optical path of laser light L. An ND filter is a filter which reduces the intensity of light without changing the relative spectral distribution of energy. A plurality of ND filters have respective extinction factors different from each other. By using one of a plurality of ND filters or combining some of them, the power regulator 401 adjusts the power of laser light L emitted from the laser light source 101 . Here, a plurality of ND filters may have the same extinction factor, and the power regulator 401 may change the number of ND filters to be moved to positions perpendicular to the optical axis of laser light L, so as to adjust the power of laser light L emitted from the laser light source 101 .
[0417] The power regulator 401 may comprise a polarization filter disposed perpendicular to the optical axis of linearly polarized laser light L, and a mechanism for rotating the polarization filter about the optical axis of laser light L by a desirable angle. Rotating the polarization filter about the optical axis by a desirable angle in the power regulator 401 adjusts the power of laser light L emitted from the laser light source 101 .
[0418] Here, the driving current for a pumping semiconductor laser in the laser light source 101 can be regulated by a laser light source controller 102 which is an embodiment of driving current control means, so as to regulate the power of laser light L emitted from the laser light source 101 . Therefore, the power of laser light L can be adjusted by at least one of the power regulator 401 and laser light source controller 102 . If the size of a modified region can attain a desirable value due to the adjustment of power of laser light L by the laser light source controller 102 alone, the power regulator 401 is unnecessary. The power adjustment explained in the foregoing is effected when an operator of the laser processing apparatus inputs the magnitude of power into an overall controller 127 , which will be explained later, by using a keyboard or the like.
[0419] The laser processing apparatus 400 further comprises a dichroic mirror 103 disposed such that the laser light L whose power is adjusted by the power regulator 401 is incident thereon whereas the orientation of the optical axis of laser light L is changed by 90°; a lens selecting mechanism 403 including a plurality of light-converging lenses for converging the laser light L reflected by the dichroic mirror 103 ; and a lens selecting mechanism controller 405 for controlling the lens selecting mechanism 403 .
[0420] The lens selecting mechanism 403 comprises light-converging lenses 105 a , 105 b , 105 c , and a support plate 407 for supporting them. The numerical apertures of respective optical systems including the light-converging lenses 105 a , 105 b , 105 c differ from each other. According to a signal from the lens selecting mechanism controller 405 , the lens selecting mechanism 403 rotates the support plate 407 , thereby causing a desirable light-converging lens among the light-converging lenses 105 a , 105 b , 105 c to be placed onto the optical axis of laser light L. Namely, the lens selecting mechanism 403 is of revolver type.
[0421] The number of light-converging lenses attached to the lens selecting mechanism 403 is not restricted to 3 but may be other numbers. When the operator of the laser processing apparatus inputs a size of numerical aperture or an instruction for choosing one of the light-converging lenses 105 a , 105 b , 105 c into the overall controller 127 , which will be explained later, by using a keyboard or the like, the light-converging lens is chosen, namely, the numerical aperture is chosen.
[0422] Mounted on the mounting table 107 of the laser processing apparatus 400 is an object to be processed 1 irradiated with the laser light L converged by one of the light-converging lenses 105 a to 105 c which is disposed on the optical axis of laser light L.
[0423] The overall controller 127 is electrically connected to the power regulator 401 . FIG. 67 does not depict it. When the magnitude of power is fed into the overall controller 127 , the latter controls the power regulator 401 , thereby adjusting the power.
[0424] FIG. 68 is a block diagram showing a part of an embodiment of the overall controller 127 . The overall controller 127 comprises a size selector 411 , a correlation storing section 413 , and an image preparing section 415 . The operator of the laser processing apparatus inputs the magnitude of power of pulse laser light or the size of numerical aperture of the optical system including the light-converging lens to the size selector 411 by using a keyboard or the like. In this embodiment, the input may choose one of the light-converging lenses 105 a , 105 b , 105 c instead of the numerical aperture size being directly inputted. In this case, the respective numerical apertures of the light-converging lenses 105 a , 105 b , 105 c are registered in the overall controller 127 beforehand, and data of the numerical aperture of the optical system including the chosen light-converging lens is automatically fed into the size selector 411 .
[0425] The correlation storing section 413 has stored the correlation between the set of pulse laser power magnitude and numerical aperture size and the size of modified spot beforehand. FIG. 69 is an embodiment of table showing this correlation. In this embodiment, respective numerical apertures of the optical systems including the light-converging lenses 105 a , 105 b , 105 c are registered in the column for numerical aperture. In the column for power, magnitudes of power attained by the power regulator 401 are registered. In the column for size, sizes of modified spots formed by combinations of powers of their corresponding sets and numerical apertures are registered. For embodiment, the modified spot formed when the power is 1.24×10 11 (W/cm 2 ) while the numerical aperture is 0.55 has a size of 120 μm. The data of this correlation can be obtained by carrying out experiments explained in FIGS. 58 to 65 before laser processing, for embodiment.
[0426] When the magnitude of power and numerical aperture size are fed into the size selector 411 , the latter chooses the set having their corresponding values from the correlation storing section 413 , and sends data of size corresponding to this set to the monitor 129 . As a consequence, the size of a modified spot formed at thus inputted magnitude of power and numerical aperture size is displayed on the monitor 129 . If there is no set corresponding to these values, size data corresponding to a set having the closest values is sent to the monitor 129 .
[0427] The data of size corresponding to the set chosen by the size selector 411 is sent from the size selector 411 to the image preparing section 415 . According to this size data, the image preparing section 415 prepares image data of a modified spot in this size, and sends thus prepared data to the monitor 129 . As a consequence, an image of the modified spot is also displayed on the monitor 129 . Hence, the size and form of modified spot can be seen before laser processing.
[0428] The size of numerical aperture may be made variable while the magnitude of power is fixed. The table in this case will be as shown in FIG. 70 . For embodiment, the modified spot formed when the numerical aperture is 0.55 while the power is fixed at 1.49×10 11 (W/cm 2 ) has a size of 150 μm. Alternatively, the magnitude of power may be made variable while the size of numerical aperture is fixed. The table in this case will be as shown in FIG. 71 . For embodiment, the modified spot formed when the power is fixed at 1.19×10 11 (W/cm 2 ) while the numerical aperture is fixed at 0.8 has a size of 30 μm.
[0429] The laser processing method in accordance with the fifth embodiment of the present invention will now be explained with reference to FIG. 67 . The object to be processed 1 is a silicon wafer. In the fifth embodiment, operations of steps S 101 to S 111 are carried out as in the laser processing method in accordance with the first embodiment shown in FIG. 15 .
[0430] After step S 111 , the magnitude of power and numerical aperture size are fed into the overall controller 127 as explained above. According to the data of power inputted, the power of laser light L is adjusted by the power regulator 401 . According to the data of numerical aperture inputted, the lens selecting mechanism 403 chooses a light-converging lens by way of the lens selecting mechanism controller 405 , thereby adjusting the numerical aperture. These data are also fed into the size selector 411 of the overall controller 127 ( FIG. 68 ). As a consequence, the size and form of a melting spot formed within the object 1 upon irradiation of one pulse of laser light L are displayed on the monitor 129 .
[0431] Then, operations of steps S 113 to S 115 are carried out as in the laser processing method in accordance with the first embodiment shown in FIG. 15 . This divides the object 1 into silicon chips.
Sixth Embodiment
[0432] A sixth embodiment of the present invention will now be explained mainly in terms of its differences from the fifth embodiment. FIG. 72 is a schematic diagram of this laser processing apparatus 500 . Among the constituents of the laser processing apparatus 500 , those identical to constituents of the laser processing apparatus 400 in accordance with the fifth embodiment shown in FIG. 67 are referred to with numerals identical thereto without repeating their overlapping explanations.
[0433] In the laser processing apparatus 500 , a beam expander 501 is disposed on the optical axis of laser light L between a power regulator 401 and a dichroic mirror 103 . The beam expander 501 has a variable magnification, and is regulated by the beam expander 501 so as to increase the beam diameter of laser light L. The beam expander 501 is an embodiment of numerical aperture regulating means. The laser processing apparatus 500 is equipped with a single light-converging lens 105 instead of the lens selecting mechanism 403 .
[0434] The operations of the laser processing apparatus 500 differ from those of the laser processing apparatus of the fifth embodiment in the adjustment of numerical aperture based on the magnitude of numerical aperture fed into the overall controller 127 . This will be explained in the following. The overall controller 127 is electrically connected to the beam expander 501 . FIG. 72 does not depict this. When the size of numerical aperture is fed into the overall controller 127 , the latter carries out control for changing the magnitude of beam expander 501 . This regulates the magnification of beam diameter of the laser light L incident on the light-converging lens 105 . Therefore, with only one light-converging lens 105 , adjustment for increasing the numerical aperture of the optical system including the light-converging lens 105 is possible. This will be explained with reference to FIGS. 73 and 74 .
[0435] FIG. 73 is a view showing the convergence of laser light L effected by the light-converging lens 105 when the beam expander 501 is not provided. On the other hand, FIG. 74 is a view showing the convergence of laser light L effected by the light-converging lens 105 when the beam expander 501 is provided. As can be seen when FIGS. 73 and 74 are compared with each other, the sixth embodiment can achieve adjustment so as to increase the numerical aperture with reference to the numerical aperture of the optical system including the light-converging lens 105 in the case where the beam expander 501 is not provided.
Seventh Embodiment
[0436] A seventh embodiment of the present invention will now be explained mainly in terms of its differences from the fifth and sixth embodiments. FIG. 75 is a schematic diagram of this laser processing apparatus 600 . Among the constituents of the laser processing apparatus 600 , those identical to constituents of the laser processing apparatus in accordance with the fifth and sixth embodiments are referred to with numerals identical thereto without repeating their overlapping explanations.
[0437] In the laser processing apparatus 600 , an iris diaphragm 601 is disposed on the optical axis of laser light L instead of the beam expander 501 between a dichroic mirror 103 and a light-converging lens 105 . Changing the aperture size of the iris diaphragm 601 adjusts the effective diameter of the light-converging lens 105 . The iris diaphragm 601 is an embodiment of numerical aperture regulating means. The laser processing apparatus 600 further comprises an iris diaphragm controller 603 for changing the aperture size of the iris diaphragm 601 . The iris diaphragm controller 603 is controlled by an overall controller 127 .
[0438] The operations of the laser processing apparatus 600 differ from those of the laser processing apparatus of the fifth and sixth embodiments in the adjustment of numerical aperture based on the size of numerical aperture fed into the overall controller 127 . According to the inputted size of numerical aperture, the laser processing apparatus 600 changes the size of aperture of the iris diaphragm 601 , thereby carrying out adjustment for decreasing the effective diameter of the light-converging lens 105 . Therefore, with only one light-converging lens 105 , adjustment for decreasing the numerical aperture of the optical system including the light-converging lens 105 is possible. This will be explained with reference to FIGS. 76 and 77 .
[0439] FIG. 76 is a view showing the convergence of laser light L effected by the light-converging lens 105 when no iris diaphragm is provided. On the other hand, FIG. 77 is a view showing the convergence of laser light L effected by the light-converging lens 105 when the iris diaphragm 601 is provided. As can be seen when FIGS. 76 and 77 are compared with each other, the seventh embodiment can achieve adjustment so as to increase the numerical aperture with reference to the numerical aperture of the optical system including the light-converging lens 105 in the case where the iris diaphragm is not provided.
[0440] Modified embodiments of the fifth to seventh embodiments of the present invention will now be explained. FIG. 78 is a block diagram of the overall controller 127 provided in a modified embodiment of the laser processing apparatus in accordance with this embodiment. The overall controller 127 comprises a power selector 417 and a correlation storing section 413 . The correlation storing section 413 has already stored the correlation data shown in FIG. 71 . An operator of the laser processing apparatus inputs a desirable size of a modified spot to the power selector 417 by a keyboard or the like. The size of modified spot is determined in view of the thickness and material of the object to be modified and the like. According to this input, the power selector 417 chooses a power corresponding to the value of size identical to thus inputted size from the correlation storing section 413 , and sends it to the power regulator 401 . Therefore, when the laser processing apparatus regulated to this magnitude of power is used for laser processing, a modified spot having a desirable size can be formed. The data concerning this magnitude of power is also sent to the monitor 129 , whereby the magnitude of power is displayed. In this embodiment, the numerical aperture is fixed while power is variable. If no size at the value identical to that of thus inputted value is stored in the correlation storing section 413 , power data corresponding to a size having the closest value is sent to the power regulator 401 and the monitor 129 . This is the same in the modified embodiments explained in the following.
[0441] FIG. 79 is a block diagram of the overall controller 127 provided in another modified embodiment of the laser processing apparatus in accordance with this embodiment. The overall controller 127 comprises a numerical aperture selector 419 and a correlation storing section 413 . It differs from the modified embodiment of FIG. 78 in that the numerical aperture is chosen instead of the power. The correlation storing section 413 has already stored the data shown in FIG. 70 . An operator of the laser processing apparatus inputs a desirable size of a modified spot to the numerical aperture selector 419 by using a keyboard or the like. As a consequence, the numerical aperture selector 419 chooses a numerical aperture corresponding to a size having a value identical to that of the inputted size from the correlation storing section 413 , and sends data of this numerical aperture to the lens selecting mechanism controller 405 , beam expander 501 , or iris diaphragm controller 603 . Therefore, when the laser processing apparatus regulated to this size of numerical aperture is used for laser processing, a modified spot having a desirable size can be formed. The data concerning this numerical aperture is also sent to the monitor 129 , whereby the size of numerical aperture is displayed. In this embodiment, the power is fixed while numerical aperture is variable.
[0442] FIG. 80 is a block diagram of the overall controller 127 provided in still another modified embodiment of the laser processing apparatus in accordance with this embodiment. The overall controller 127 comprises a set selector 421 and a correlation storing section 413 . It differs from the embodiments of FIGS. 78 and 79 in that both power and numerical aperture are chosen. The correlation storing section 413 has stored the correlation between the set of power and numerical aperture and the size in FIG. 69 beforehand. An operator of the laser processing apparatus inputs a desirable size of a modified spot to the set selector 421 by using a keyboard or the like. As a consequence, the set selector 421 chooses a set of power and numerical aperture corresponding to thus inputted size from the correlation storing section 413 . Data of power in thus chosen set is sent to the power regulator 401 . On the other hand, data of numerical aperture in the chosen set is sent to the lens selecting mechanism controller 405 , beam expander 501 , or iris diaphragm controller 603 . Therefore, when the laser processing apparatus regulated to the power and numerical aperture of this set is used for laser processing, a modified spot having a desirable size can be formed. The data concerning the magnitude of power and size of numerical aperture is also sent to the monitor 129 , whereby the magnitude of power and size of numerical aperture is displayed.
[0443] These modified embodiments can control sizes of modified spots. Therefore, when the size of a modified spot is made smaller, the object to be processed can precisely be cut along a line along which the object is intended to be cut therein, and a flat cross section can be obtained. When the object to be cut has a large thickness, the size of modified spot can be enhanced, whereby the object can be cut.
Eighth Embodiment
[0444] An eighth embodiment of the present invention controls the distance between a modified spot formed by one pulse of laser light and a modified spot formed by the next one pulse of pulse laser light by regulating the magnitude of a repetition frequency of pulse laser light and the magnitude of relative moving speed of the light-converging point of pulse laser light. Namely, it controls the distance between adjacent modified spots. In the following explanation, the distance is assumed to be a pitch p. The control of pitch p will be explained in terms of a crack region by way of embodiment.
[0445] Let f (Hz) be the repetition frequency of pulse laser light, and v (mm/sec) be the moving speed of the X-axis stage or Y-axis stage of the object to be processed. The moving speeds of these stages are embodiments of relative moving speed of the light-converging point of pulse laser light. The crack part formed by one shot of pulse laser light is referred to as crack spot. Therefore, the number n of crack spots formed per unit length of the line 5 along which the object is intended to be cut is as follows:
[0000]
n=f/v.
[0446] The reciprocal of the number n of crack spots formed per unit length corresponds to the pitch p:
[0000] p= 1/ n.
[0447] Hence, the pitch p can be controlled when at least one of the magnitude of repetition frequency of pulse laser light and the magnitude of relative moving speed of the light-converging point is regulated. Namely, the pitch p can be controlled so as to become smaller when the repetition frequency f(Hz) is increased or when the stage moving speed v(mm/sec) is decreased. By contrast, the pitch p can be controlled so as to become greater when the repetition frequency f(Hz) is decreased or when the stage moving speed v(mm/sec) is increased.
[0448] Meanwhile, there are three ways of relationship between the pitch p and crack spot size in the direction of line 5 along which the object is intended to be cut as shown in FIGS. 81 to 83 . FIGS. 81 to 83 are plan views of an object to be processed along the line 5 along which the object is intended to be cut, which is formed with a crack region by the laser processing in accordance with this embodiment. A crack spot 90 is formed by one pulse of pulse laser light. Forming a plurality of crack spots 90 aligning each other along the line 5 along which the object is intended to be cut yields a crack region 9 .
[0449] FIG. 81 shows a case where the pitch p is greater than the size d. The crack region 9 is formed discontinuously along the line 5 along which the object is intended to be cut within the object to be processed. FIG. 82 shows a case where the pitch p substantially equals the sized. The crack region 9 is formed continuously along the line 5 along which the object is intended to be cut within the object to be processed. FIG. 83 shows a case where the pitch p is smaller than the size d. The crack region 9 is formed continuously along the line 5 along which the object is intended to be cut within the object to be processed.
[0450] In FIG. 81 , the crack region 9 is not continuous along the line 5 along which the object is intended to be cut, whereby the part of line 5 along which the object is intended to be cut keeps a strength to some extent. Therefore, when carrying out a step of cutting the object to be processed after laser processing, handling of the object becomes easier. In FIGS. 82 and 83 , the crack region 9 is continuously formed along the line 5 along which the object is intended to be cut, which makes it easy to cut the object while using the crack region 9 as a starting point.
[0451] The pitch p is made greater than the size d in FIG. 81 , and substantially equals the size d in FIG. 82 , whereby regions generating multiphoton absorption upon irradiation with pulse laser light can be prevented from being superposed on crack spots 90 which have already been formed. As a result, deviations in sizes of crack spots 90 can be made smaller. Namely, the inventor has found that, when a region generating multiphoton absorption upon irradiation with pulse laser light is superposed on crack spots 90 which have already been formed, deviations in sizes of crack spots 90 formed in this region become greater. When deviations in sizes of crack spots 90 become greater, it becomes harder to cut the object along a line along which the object is intended to be cut precisely, and the flatness of cross section deteriorates. In FIGS. 81 and 82 , deviations in sizes of crack spots can be made smaller, whereby the object to be processed can be cut along the line along which the object is intended to be cut precisely, while cross sections can be made flat.
[0452] As explained in the foregoing, the eighth embodiment of the present invention can control the pitch p by regulating the magnitude of repetition frequency of pulse laser light or magnitude of relative moving speed of the light-converging point of pulse laser light. This enables laser processing in conformity to the object to be processed by changing the pitch p in view of the thickness and material of the object and the like.
[0453] Though the fact that the pitch p can be controlled is explained in the case of crack spots, the same holds in melting spots and refractive index change spots. However, there are no problems even when melting spots and refractive index change spots are superposed on those which have already been formed. The relative movement of the light-converging point of pulse laser light may be realized by a case where the object to be processed is moved while the light-converging point of pulse laser light is fixed, a case where the light-converging point of pulse laser light is moved while the object is fixed, a case where the object and the light-converging point of pulse laser light are moved in directions opposite from each other, and a case where the object and the light-converging point of pulse laser light are moved in the same direction with their respective speeds different from each other.
[0454] With reference to FIG. 14 , the laser processing apparatus in accordance with the eighth embodiment of the present invention will be explained mainly in terms of its differences from the laser processing apparatus 100 in accordance with the first embodiment shown in FIG. 14 . The laser light source 101 is a Q-switch laser. FIG. 84 is a schematic diagram of the Q-switch laser provided in a laser light source 101 . The Q-switch laser comprises mirrors 51 , 53 which are disposed with a predetermined gap therebetween, a laser medium 55 disposed between the mirrors 51 and 53 , a pumping source 57 for applying a pumping input to the laser medium 55 , and a Q-switch 59 disposed between the laser medium 55 and the mirror 51 . The material of the laser medium 55 is Nd:YAG, for embodiment.
[0455] A pumping input is applied from the pumping source 57 to the laser medium 55 in a state where the loss in a resonator is made high by utilizing the Q-switch 59 , whereby the population inversion of the laser medium 55 is raised to a predetermined value. Thereafter, the Q-switch 59 is utilized for placing the resonator into a state with a low loss, so as to oscillate the accumulated energy instantaneously and generate pulse laser light L. A signal S (e.g., a change in a repetition frequency of an ultrasonic pulse) from a laser light source controller 102 controls the Q-switch 59 so as to make it attain a high state. Therefore, the signal S from the laser light source controller 102 can regulate the repetition frequency of pulse laser light L emitted from the laser light source 101 . The laser light source controller 102 is an embodiment of frequency adjusting means. The repetition frequency is regulated when an operator of the laser processing apparatus inputs the magnitude of repetition frequency to an overall controller 127 , which will be explained later, by using a keyboard or the like. The foregoing are details of the laser light source 101 .
[0456] During the laser processing, the object to be processed 1 is moved in the X- or Y-axis direction, so as to form a modified region along a line along which the object is intended to be cut. Therefore, when forming a modified region in the X-axis direction, the speed of relative movement of the light-converging point of laser light can be adjusted by regulating the moving speed of the X-axis stage 109 . When forming a modified region in the Y-axis direction, on the other hand, the speed of relative movement of the light-converging point of laser light can be adjusted by regulating the moving speed of the Y-axis stage 111 . The adjustment of the respective moving speeds of these stages is controlled by the stage controller 115 . The stage controller 115 is an embodiment of speed adjusting means. The speed is regulated when the operator of laser processing apparatus inputs the magnitude of speed to the overall controller 127 , which will be explained later, by using a keyboard or the like. The speed of relative movement of the light-converging point of pulse laser light can be adjusted when, while the light-converging point P is made movable, its moving speed is regulated.
[0457] The overall controller 127 of the laser processing apparatus in accordance with the eighth embodiment further adds other functions to the overall controller 127 of the laser processing apparatus in accordance with the first embodiment. FIG. 85 is a block diagram showing a part of an embodiment of the overall controller 127 of the laser processing apparatus in accordance with the eighth embodiment. The overall controller 127 comprises a distance calculating section 141 , a size storing section 143 , and an image preparing section 145 . To the distance calculating section 141 , the magnitude of repetition frequency of pulse laser light and respective magnitudes of moving speeds of the stages 109 , 111 are inputted. These inputs are effected by the operator of laser processing apparatus using a keyboard or the like.
[0458] The distance calculating section 141 calculates the distance (pitch) between adjacent spots by utilizing the above-mentioned expressions (n=f/v, and p=1/n). The distance calculating section 141 sends this distance data to the monitor 129 . As a consequence, the distance between modified spots formed at the inputted magnitudes of frequency and speed is displayed on the monitor 129 .
[0459] The distance data is also sent to the image preparing section 145 . The size storing section 143 has already stored therein sizes of modified spots formed in this laser processing apparatus. According to the distance data and the size data stored in the size storing section 143 , the image preparing section 145 prepares image data of a modified region formed by the distance and size, and sends thus prepared image data to the monitor 129 . As a consequence, an image of the modified region is also displayed on the monitor 129 . Hence, the distance between adjacent modified spots and the form of modified region can be seen before laser processing.
[0460] Though the distance calculating section 141 calculates the distance between modified spots by utilizing the expressions (n=f/v, and p=1/n), the following procedure may also be taken. First, a table having registered the relationship between the magnitude of repetition frequency, the moving speeds of stages 109 , 111 , and the distance between modified spots beforehand is prepared, and the distance calculating section 141 is caused to store data of this table. When the magnitude of repetition frequency and the magnitudes of moving speeds of stages 109 , 111 are fed into the distance calculating section 141 , the latter reads out from the above-mentioned table the distance between modified spots in the modified spots formed under the condition of these magnitude.
[0461] Here, the magnitudes of stage moving speeds may be made variable while the magnitude of repetition frequency is fixed. On the contrary, the magnitude of repetition frequency may be made variable while the magnitudes of stage moving speeds are fixed. Also, in these cases, the above-mentioned expressions and table are used in the distance calculating section 141 for carrying out processing for causing the monitor 129 to display the distance between modified spots and an image of the modified region.
[0462] As in the foregoing, the overall controller 127 shown in FIG. 85 inputs the magnitude of repetition frequency and the stage moving speeds, thereby calculating the distance between adjacent modified spots. Alternatively, a desirable distance between adjacent modified spots may be inputted, and the magnitude of repetition frequency and magnitudes of stage moving speeds may be controlled. This procedure will be explained in the following.
[0463] FIG. 86 is a block diagram showing a part of another embodiment of the overall controller 127 provided in the eighth embodiment. The overall controller 127 comprises a frequency calculating section 147 . The operator of laser processing apparatus inputs the magnitude of distance between adjacent modified spots to the frequency calculating section 147 by using a keyboard or the like. The magnitude of distance is determined in view of the thickness and material of the object to be processed and the like. Upon this input, the frequency calculating section 147 calculates a frequency for attaining this magnitude of distance according to the above-mentioned expressions and tables. In this embodiment, the stage moving speeds are fixed. The frequency calculating section 147 sends thus calculated data to the laser light source controller 102 . When the object to be processed is subjected to laser processing by the laser processing apparatus regulated to this magnitude of frequency, the distance between adjacent modified spots can attain a desirable magnitude. Data of this magnitude of frequency is also sent to the monitor 129 , whereby this magnitude of frequency is displayed.
[0464] FIG. 87 is a block diagram showing a part of still another embodiment the overall controller 127 provided in the eighth embodiment. The overall controller 127 comprises a speed calculating section 149 . In a manner similar to that mentioned above, the magnitude of distance between adjacent modified spots is fed into the speed calculating section 149 . Upon this input, the speed calculating section 149 calculates a stage moving speed for attaining this magnitude of distance according to the above-mentioned expressions and tables. In this embodiment, the repetition frequency is fixed. The speed calculating section 149 sends thus calculated data to the stage controller 115 . When the object to be processed is subjected to laser processing by the laser processing apparatus regulated to this magnitude of stage moving speed, the distance between adjacent modified spots can attain a desirable magnitude. Data of this magnitude of stage moving speed is also sent to the monitor 129 , whereby this magnitude of stage moving speed is displayed.
[0465] FIG. 88 is a block diagram showing a part of still another embodiment of the overall controller 127 provided in the eighth embodiment. The overall controller 127 comprises a combination calculating section 151 . It differs from the cases of FIGS. 86 and 87 in that both repetition frequency and stage moving speed are calculated. In a manner similar to that mentioned above, the distance between adjacent modified spots is fed into the combination calculating section 151 . According to the above-mentioned expressions and tables, the combination calculating section 151 calculates a repetition frequency and a stage moving speed for attaining this magnitude of distance.
[0466] The combination calculating section 151 sends thus calculated data to the stage controller 115 . The laser light source controller 102 adjusts the laser light source 101 so as to attain the calculated magnitude of repetition frequency. The stage controller 115 adjusts the stages 109 , 111 so as to attain the calculated magnitude of stage moving speed. When the object to be processed is subjected to laser processing by thus regulated laser processing apparatus, the distance between adjacent modified spots can attain a desirable magnitude. Data of thus calculated magnitude of repetition frequency and magnitude of stage moving speed are also sent to the monitor 129 , whereby thus calculated values are displayed.
[0467] The laser processing method in accordance with the eighth embodiment of the present invention will now be explained. The object to be processed 1 is a silicon wafer. In the eighth embodiment, operations from steps S 101 to S 111 are carried out in a manner similar to that of the laser processing method in accordance with the first embodiment shown in FIG. 15 .
[0468] After step S 111 , the distance between adjacent melting spots in the melting spots formed by one pulse of pulse laser, i.e., the magnitude of pitch p, is determined. The pitch p is determined in view of the thickness and material of the object 1 and the like. The magnitude of pitch p is fed into the overall controller 127 shown in FIG. 88 .
[0469] Then, in a manner similar to that of the laser processing method in accordance with the first embodiment shown in FIG. 15 , operations of step S 113 to S 115 are carried out. This divides the object 1 into silicon chips.
[0470] As explained in the foregoing, the eighth embodiment can control the distance between adjacent melting spots by regulating the magnitude of repetition frequency of pulse laser light, and regulating the magnitudes of moving speeds of X-axis stage 109 and Y-axis stage 111 . Changing the magnitude of distance in view of the thickness and material of the object 1 and the like enables processing in conformity to the aimed purpose.
Ninth Embodiment
[0471] A ninth embodiment of the present invention changes the position of the light-converging point of laser light irradiating the object to be processed in the direction of incidence to the object, thereby forming a plurality of modified regions aligning in the direction of incidence.
[0472] Forming a plurality of modified regions will be explained in terms of a crack region by way of embodiment. FIG. 89 is a perspective view of an object to be processed 1 formed with two crack regions 9 within the object 1 by using the laser processing method in accordance with the ninth embodiment of the present invention.
[0473] A method of forming two crack regions 9 will be explained in brief. First, the object 1 is irradiated with pulse laser light L, while the light-converging point of pulse laser light L is located within the object 1 near its rear face 21 and is moved along a line 5 along which the object is intended to be cut. This forms a crack region 9 ( 9 A) along the line 5 along which the object is intended to be cut within the object 1 near the rear face 21 . Subsequently, the object 1 is irradiated with the pulse laser light L, while the light-converging point of pulse laser light L is located within the object 1 near its surface 3 and is moved along the line 5 along which the object is intended to be cut. This forms a crack region 9 ( 9 B) along the line 5 along which the object is intended to be cut within the object 1 near the surface 3 .
[0474] Then, as shown in FIG. 90 , cracks 91 naturally grow from the crack regions 9 A, 9 B. Specifically, the cracks 91 naturally grow from the crack region 9 A toward the rear face 21 , from the crack region 9 A ( 9 B) toward the crack region 9 B ( 9 A), and from the crack region 9 B toward the surface 3 . This can form cracks 9 elongated in the thickness direction of the object in the surface of object 1 extending along the line 5 along which the object is intended to be cut, i.e., the surface to become a cross section. Hence, the object 1 can be cut along the line 5 along which the object is intended to be cut by artificially applying a relatively small force thereto or naturally without applying such a force.
[0475] As in the foregoing, the ninth embodiment forms a plurality of crack regions 9 , thereby increasing the number of locations to become starting points when cutting the object 1 . As a consequence, the ninth embodiment makes it possible to cut the object 1 even in the cases where the object 1 has a relatively large thickness, the object 1 is made of a material in which cracks 91 are hard to grow after forming the crack regions 9 , and so forth.
[0476] When cutting is difficult by two crack regions 9 alone, three or more crack regions 9 are formed. For embodiment, as shown in FIG. 91 , a crack region 9 C is formed between the crack region 9 A and crack region 9 B. Cutting can also be achieved in a direction orthogonal to the thickness direction of the object 1 as long as it is the direction of incidence of laser light as shown in FIG. 92 .
[0477] Preferably, in the ninth embodiment of the present invention, a plurality of crack regions 9 are successively formed from the side farther from the entrance face (e.g., surface 3 ) of the object to be processed on which the pulse laser light L is incident. For embodiment, in FIG. 89 , the crack region 9 A is formed first, and then the crack region 9 B is formed. If the crack regions 9 are formed successively from the side closer to the entrance face, the pulse laser L irradiated at the time of forming the crack region 9 to be formed later will be scattered by the crack region 9 formed earlier. As a consequence, deviations occur in sizes of the crack part (crack spot) formed by one shot of pulse laser light L constituting the crack region 9 formed later. Hence, the crack region 9 formed later cannot be formed uniformly. Forming the crack regions 9 successively from the side farther from the entrance face does not generate the above-mentioned scattering, whereby the crack region 9 formed later can be formed uniformly.
[0478] However, the order of forming a plurality of crack regions 9 in the ninth embodiment of the present invention is not restricted to that mentioned above. They may be formed successively from the side closer to the entrance face of the object to be processed, or formed randomly. In the random forming, for embodiment in FIG. 91 , the crack region 9 C is formed first, then the crack region 9 B, and finally the crack region 9 A is formed by reversing the direction of incidence of laser light.
[0479] Though the forming of a plurality of modified regions is explained in the case of crack regions, the same holds in molten processed regions and refractive index change regions. Though the explanation relates to pulse laser light, the same holds for continuous wave laser light.
[0480] The laser processing apparatus in accordance with the ninth embodiment of the present invention has a configuration similar to that of the laser processing apparatus 100 in accordance with the first embodiment shown in FIG. 14 . In the ninth embodiment, the position of light-converging point P in the thickness direction of the object to be processed 1 is adjusted by the Z-axis stage 113 . This can adjust the light-converging point P so as to locate it at a position closer to or farther from the entrance face (surface 3 ) than is a half thickness position in the thickness direction of the object to be processed 1 , and at a substantially half thickness position.
[0481] Here, adjustment of the position of light-converging point P in the thickness direction of the object to be processed caused by the Z-axis stage will be explained with reference to FIGS. 93 and 94 . In the ninth embodiment of the present invention, the position of light-converging point of laser light in the thickness direction of the object to be processed is adjusted so as to be located at a desirable position within the object with reference to the surface (entrance face) of the object. FIG. 93 shows the state where the light-converging point P of laser light L is positioned at the surface 3 of the object 1 . When the Z-axis stage is moved by z toward the light-converging lens 105 , the light-converging point P moves from the surface 3 to the inside of the object 1 as shown in FIG. 94 . The amount of movement of light-converging point P within the object 1 is Nz (where N is the refractive index of the object 1 with respect to the laser light L). Hence, when the Z-axis stage is moved in view of the refractive index of the object 1 with respect to the laser light L, the position of light-converging point P in the thickness direction of the object 1 can be controlled. Namely, a desirable position of the light-converging point P in the thickness direction of the object 1 is defined as the distance (Nz) from the surface 3 to the inside of the object 1 . The object 1 is moved in the thickness direction by the amount of movement (z) obtained by dividing the distance (Nz) by the above-mentioned refractive index (N). This can locate the light-converging point P at the desirable position.
[0482] As explained in the first embodiment, the stage controller 115 controls the movement of the Z-axis stage 113 according to focal point data, such that the focal point of visible light is located at the surface 3 . The laser processing apparatus 1 is adjusted such that the light-converging point P of laser light L is positioned at the surface 3 at the position of Z-axis stage 113 where the focal point of visible light is located at the surface 3 . Data of the amount of movement (z) explained in FIGS. 93 and 94 is fed into and stored in the overall controller 127 .
[0483] With reference to FIG. 95 , the laser processing method in accordance with the ninth embodiment of the present invention will now be explained. FIG. 95 is a flowchart for explaining this laser processing method. The object to be processed 1 is a silicon wafer.
[0484] Step S 101 is the same as step S 101 of the first embodiment shown in FIG. 15 . Subsequently, the thickness of the object 1 is measured. According to the result of measurement of thickness and the refractive index of object 1 , the amount of movement (z) of object 1 in the Z-axis direction is determined (S 103 ). This is the amount of movement of object 1 in the Z-axis direction with reference to the light-converging point of laser light L positioned at the surface 3 of object 1 in order for the light-converging point P of laser light L to be located within the object 1 . Namely, the position of light-converging point P in the thickness direction of object 1 is determined. The position of light-converging point P is determined in view of the thickness and material of object 1 and the like. In this embodiment, data of a first movement amount for positioning the light-converging point P near the rear face within the object 1 and data of a second movement amount for positioning the light-converging point P near the surface 3 within the object 1 are used. A first molten processed region to be formed is formed by using the data of first movement amount. A second molten processed region to be formed is formed by using the data of second movement amount. Data of these movement amounts are fed into the overall controller 127 .
[0485] Steps S 105 and S 107 are the same as steps S 105 and S 107 in the first embodiment shown in FIG. 15 . The focal point data calculated by step S 107 is sent to the stage controller 115 . According to the focal point data, the stage controller 115 moves the Z-axis stage 113 in the Z-axis direction (S 109 ). This positions the focal point of visible light of the observation light source 117 at the surface 3 . At this point of Z-axis stage 113 , the focal point P of pulse laser light L is positioned at the surface 3 . Here, according to imaging data, the imaging data processor 125 calculates enlarged image data of the surface of object 1 including the line 5 along which the object is intended to be cut. The enlarged image data is sent to the monitor 129 by way of the overall controller 127 , whereby an enlarged image in the vicinity of the line 5 along which the object is intended to be cut is displayed on the monitor 129 .
[0486] The data of first movement amount determined by step S 103 has already been inputted to the overall controller 127 , and is sent to the stage controller 115 . According to this data of movement amount, the stage controller 115 moves the object 1 in the Z-axis direction by using the Z-axis stage 113 to a position where the light-converging point P of laser light L is located within the object 1 (S 111 ). This inside position is near the rear face of the object 1 .
[0487] Next, as in step S 113 of the first embodiment shown in FIG. 15 , a molten processed region is formed within the object 1 so as to extend along the line 5 along which the object is intended to be cut (S 113 ). The molten processed region is formed near the rear face within the object 1 .
[0488] Then, according to the data of second movement amount as in step S 111 , the object 1 is moved in the Z-axis direction by the Z-axis stage 113 to a position where the light-converging point P of laser light L is located within the object 1 (S 115 ). Subsequently, as in step S 113 , a molten processed region is formed within the object 1 (S 117 ). In this step, the molten processed region is formed near the surface 3 within the object 1 .
[0489] Finally, the object 1 is bent along the line 5 along which the object is intended to be cut, and thus is cut (S 119 ). This divides the object 1 into silicon chips.
[0490] Effects of the ninth embodiment of the present invention will be explained. The ninth embodiment forms a plurality of modified regions aligning in the direction of incidence, thereby increasing the number of locations to become starting points when cutting the object 1 . In the case where the size of object 1 in the direction of incidence of laser light is relatively large or where the object 1 is made of a material in which cracks are hard to grow from a modified region, for embodiment, the object 1 is hard to cut when only one modified region exists along the line 5 along which the object is intended to be cut. In such a case, forming a plurality of modified regions as in this embodiment can easily cut the object 1 .
Tenth Embodiment
[0491] A tenth embodiment of the present invention controls the position of a modified region in the thickness direction of an object to be processed by adjusting the light-converging point of laser light in the thickness direction of the object.
[0492] This positional control will be explained in terms of a crack region by way of embodiment. FIG. 96 is a perspective view of an object to be processed 1 in which a crack region 9 is formed within the object 1 by using the laser processing method in accordance with the tenth embodiment of the present invention. The light-converging point of pulse laser L is located within the object 1 through the surface (entrance face) 3 of the object with respect to the pulse laser light L. The light-converging point is adjusted so as to be located at a substantially half thickness position in the thickness direction of the object 1 . When the object to be processed 1 is irradiated with the line 5 along which the object is intended to be cut under these conditions, a crack region 9 is formed along a line 5 along which the object is intended to be cut at a half thickness position of the object 1 and its vicinity.
[0493] FIG. 97 is a partly sectional view of the object 1 shown in FIG. 96 . After the crack region 9 is formed, cracks 91 are naturally grown toward the surface 3 and rear face 21 . When the crack region 9 is formed at the half thickness position and its vicinity in the thickness direction of the object 1 , the distance between the naturally growing crack 91 and the surface 3 (rear face 21 ) can be made relatively long, for embodiment, in the case where the object 1 has a relatively large thickness. Therefore, apart to be cut extending along the line 5 along which the object is intended to be cut in the object 1 maintains a strength to a certain extent. Therefore, when carrying out the step of cutting the object 1 after terminating the laser processing, handling the object becomes easier.
[0494] FIG. 98 is a perspective view of an object to be processed 1 including a crack region 9 formed by using the laser processing method in accordance with the tenth embodiment of the present invention as with FIG. 96 . The crack region 9 shown in FIG. 98 is formed when the light-converging point of pulse laser light L is adjusted so as to be located at a position closer to the surface (entrance face) 3 than is a half thickness position in the thickness direction of the object 1 . The crack region 9 is formed on the surface 3 side within the object 1 . FIG. 99 is a partly sectional view of the object 1 shown in FIG. 98 . Since the crack region 9 is formed on the surface 3 side, naturally growing cracks 91 reach the surface 3 or its vicinity. Hence, fractures extending along the line 5 along which the object is intended to be cut are likely to occur in the surface 3 , whereby the object 1 can be cut easily.
[0495] In the case where the surface 3 of the object 1 is formed with electronic devices and electrode patterns in particular, forming the crack region 9 near the surface 3 can prevent the electronic devices and the like from being damaged when cutting the object 1 . Namely, growing cracks 91 from the crack region 9 toward the surface 3 and rear face 21 of the object 1 cuts the object 1 . Cutting may be achieved by the natural growth of cracks 91 alone or by artificially growing cracks 91 in addition to the natural growth of crack 91 . When the distance between the crack region 9 and the surface 3 is relatively long, the deviation in the growing direction of cracks 91 on the surface 3 side becomes greater. As a consequence, the cracks 91 may reach regions formed with electronic devices and the like, thereby damaging the electronic devices and the like. When the crack region 9 is formed near the surface 3 , the distance between the crack region 9 and the surface 3 is relatively short, whereby the deviation in growing direction of cracks 91 can be made smaller. Therefore, cutting can be effected without damaging the electronic devices and the like. When the crack region 9 is formed at a location too close to the surface 3 , the crack region 9 is formed at the surface 3 . As a consequence, the random form of the crack region 9 itself appears at the surface 3 , which causes chipping, thereby deteriorating the accuracy in breaking and cutting.
[0496] The crack region 9 can also be formed while the light-converging point of pulse laser light L is adjusted so as to be located at a position farther from the surface 3 than is a half thickness position in the thickness direction of the object 1 . In this case, the crack region 9 is formed on the rear face 21 side within the object 1 .
[0497] As with FIG. 96 , FIG. 100 is a perspective view of the object 1 including crack regions formed by using the laser processing method in accordance with the tenth embodiment of the present invention. The crack region 9 in the X-axis direction shown in FIG. 100 is formed when the light-converging point of pulse laser light L is adjusted so as to be located at a position farther from the surface (entrance face) 3 than is a half thickness position in the thickness direction of the object 1 . The crack region 9 in the Y-axis direction is formed when the light-converging point of pulse laser light L is adjusted so as to be located at a position closer to the surface 3 than is the half thickness position in the thickness direction of the object 1 . The crack region 9 in the X-axis direction and the crack region 9 in the Y-axis direction cross each other three-dimensionally.
[0498] When the object 1 is a semiconductor wafer, for embodiment, a plurality of crack regions 9 are formed in parallel in each of the X- and Y-axis directions. This forms the crack regions 9 like a lattice in the semiconductor wafer, whereas the latter is divided into individual chips while using the lattice-like crack regions as starting points. When the crack region 9 in the X-axis direction and the crack region 9 in the Y-axis direction are located at the same position in the thickness direction of the object 1 , there occurs a location where the crack region 9 in the X-axis direction and the crack region 9 in the Y-axis direction intersect each other at right angles. At the location where the crack regions 9 intersect each other at right angles, they are superposed on each other, which makes it difficult for the cross section in the X-axis direction and the cross section in the Y-axis direction to intersect each other at right angles with a high accuracy. This inhibits the object 1 from being cut precisely at the intersection.
[0499] When the position of the crack region 9 in the X-axis direction and the position of the crack region 9 in the Y-axis direction differ from each other in the thickness direction of the object 1 as shown in FIG. 100 , the crack region 9 in the X-axis direction and the crack region 9 in the Y-axis direction can be prevented from being superposed on each other. This enables precise cutting of the object 1 .
[0500] In the crack region 9 in the X-axis direction and the crack region 9 in the Y-axis direction, the crack region 9 to be formed later is preferably formed closer to the surface (entrance face) 3 than is the crack region 9 formed earlier. If the crack region 9 to be formed later is formed closer to the rear face 21 than is the crack region 9 formed earlier, the pulse laser light L irradiated when forming the crack region 9 to be formed later is scattered by the crack region 9 formed earlier at the location where the cross section in the X-axis direction and the cross section in the Y-axis direction intersect each other at right angles. This forms deviations between the size of a part formed at a position to become the above-mentioned intersecting location and the size of a part formed at another position in the crack region 9 to be formed later. Therefore, the crack region 9 to be formed later cannot be formed uniformly.
[0501] When the crack region 9 to be formed later is formed closer to the surface 3 than is the crack region 9 formed earlier, by contrast, scattering of the pulse laser light L does not occur at a position to become the above-mentioned intersecting location, whereby the crack region 9 to be formed later can be formed uniformly.
[0502] As explained in the foregoing, the tenth embodiment of the present invention adjusts the position of light-converging point of laser light in the thickness direction of an object to be processed, thereby being able to control the position of a modified region in the thickness direction of the object. Changing the position of light-converging point in view of the thickness and material of the object to be processed and the like enables laser processing in conformity to the object.
[0503] Though the fact that the position of a modified region can be controlled is explained in the case of a crack region, the same holds in molten processed regions and refractive index change regions. Though the explanation relates to pulse laser light, the same holds for continuous wave laser light.
[0504] The laser processing apparatus in accordance with the tenth embodiment of the present invention has a configuration similar to the laser processing apparatus 100 in accordance with the first embodiment shown in FIG. 14 . In the tenth embodiment, the Z-axis stage 113 adjusts the position of light-converging point Pin the thickness direction of object 1 . This can adjust the light-converging point P so as to locate it at a position closer to or farther from the entrance face (surface 3 ) than is a half thickness position in the thickness direction of the object 1 or at a substantially half thickness position, for embodiment. These adjustment operations and the placement of the light-converging point of laser light within the object can also be achieved by moving the light-converging lens 105 in the Z-axis direction. Since there are cases where the object 1 moves in the thickness direction thereof and where the light-converging lens 105 moves in the thickness direction of the object 1 in the present invention, the amount of movement of the object 1 in the thickness direction of the object 1 is defined as a first relative movement amount or a second relative movement amount.
[0505] The adjustment of light-converging point P in the thickness direction of the object to be processed caused by the Z-axis stage is the same as that in the ninth embodiment explained with reference to FIG. 93 and FIG. 94 .
[0506] The imaging data processor 125 calculates focal point data for locating the focal point of visible light generated by the observation light source 117 on the surface 3 according to the imaging data in the tenth embodiment as well. According to this focal point data, the stage controller 115 controls the movement of the Z-axis stage 113 , so as to locate the focal point of visible light at the surface 3 . The laser processing apparatus 1 is adjusted such that the light-converging point P of laser light L is located at the surface 3 at the position of Z-axis stage 113 where the focal point of visible light is located at the surface 3 . Hence, the focal point data is an embodiment of second relative movement amount of the object 1 in the thickness direction thereof required for locating the light-converging point P at the surface (entrance face) 3 . The imaging data processor 125 has a function of calculating the second relative movement amount.
[0507] Data of the movement amount (z) explained with reference to FIGS. 93 and 94 is fed into and stored in the overall controller 127 . Namely, the overall controller 127 has a function of storing data of the relative movement amount of the object to be processed 1 in the thickness direction of the object 1 . The overall controller 127 , stage controller 115 , and Z-axis stage 113 adjust the position of light-converging point of pulse laser light converged by the light-converging lens within the range of thickness of the object 1 .
[0508] The laser processing method in accordance with the tenth embodiment will be explained with reference to the laser processing apparatus in accordance with the first embodiment shown in FIG. 14 and the flowchart for the laser processing method in accordance with the first embodiment shown in FIG. 15 . The object to be processed 1 is a silicon wafer.
[0509] Step S 101 is the same as step S 101 of the first embodiment shown in FIG. 15 . Subsequently, as in step S 103 of the first embodiment shown in FIG. 15 , the thickness of object 1 is measured. According to the result of measurement of thickness and the refractive index, the amount of movement (z) in the Z-axis direction of object 1 is determined (S 103 ). This is the amount of movement of object 1 in the Z-axis direction with reference to the light-converging point of laser light L positioned at the surface 3 of object 1 required for positioning the light-converging point P of laser light L within the object 1 . Namely, the position of light-converging point P in the thickness direction of object 1 is determined. The amount of movement (z) in the Z-axis direction is one embodiment of data of relative movement of the object 1 in the thickness direction thereof. The position of light-converging point P is determined in view of the thickness and material of the object 1 , effects of processing (e.g., easiness to handle and cut the object), and the like. This data of movement amount is fed into the overall controller 127 .
[0510] Steps S 105 and S 107 are similar to steps S 105 and S 107 of the first embodiment shown in FIG. 15 . The focal point data calculated by step S 107 is data of a second movement amount in the Z-axis direction of object 1 .
[0511] This focal point data is sent to the stage controller 115 . According to this focal point data, the stage controller 115 moves the Z-axis stage 113 in the Z-axis direction (S 109 ). This positions the focal point of visible light of the observation light source 117 at the surface 3 . At this position of Z-axis stage 113 , the light-converging point P of pulse laser light L is positioned at the surface 3 . According to imaging data, the imaging data processor 125 calculates enlarged image data of the surface of object 1 including the line 5 along which the object is intended to be cut. This enlarged image data is sent to the monitor 129 by way of the overall controller 127 , whereby an enlarged image near the line 5 along which the object is intended to be cut is displayed on the monitor 127 .
[0512] Data of the relative movement amount determined by step S 103 has already been inputted to the overall controller 127 , and is sent to the stage controller 115 . According to this data of movement amount, the stage controller 115 causes the Z-axis stage 113 to move the object 1 in the Z-axis direction at a position where the light-converging point P of laser light is located within the object 1 (S 111 ).
[0513] Steps S 113 and S 115 are similar to steps S 113 and S 115 shown in FIG. 15 . The foregoing divides the object 1 into silicon chips.
[0514] Effects of the tenth embodiment of the present invention will be explained. The tenth embodiment irradiates the object to be processed 1 with pulse laser light L while adjusting the position of light-converging point P in the thickness direction of object 1 , thereby forming a modified region. This can control the position of a modified region in the thickness direction of object 1 . Therefore, changing the position of a modified region in the thickness direction of object 1 according to the material and thickness of object 1 , effects of processing, and the like enables cutting in conformity to the object 1 .
Eleventh Embodiment
[0515] A Eleventh embodiment of the present invention will now be explained. The laser processing method in accordance with the eleventh embodiment comprises a modified region forming step (first step) of forming a modified region caused by multiphoton absorption within an object to be processed, and a stress step (second step) of generating a stress at a part where the object is cut. In the eleventh embodiment, the same laser light irradiation is carried out in the modified region forming step and stress step. Therefore, a laser processing apparatus, which was explained above, emits laser light twice under the same condition in the modified region forming step and stress step, respectively.
[0516] With reference to FIGS. 14 and 101 , the laser processing method in accordance with the eleventh embodiment will now be explained. FIG. 101 is a flowchart for explaining the laser processing method.
[0517] Steps S 101 , S 103 , S 105 , S 107 , S 109 and S 111 shown in FIG. 101 , are the same as theses shown in FIG. 15 , and therefore, the detailed explanations of the Steps S 101 , S 103 , S 105 , S 107 , S 109 and S 111 are omitted.
[0518] After Step S 111 , laser light L is generated from the laser light source 101 , so as to irradiate the line 5 along which the object is intended to be cut 5 in the surface 3 of the object 1 therewith. FIG. 102 is a sectional view of the object 1 including a crack region 9 during laser processing in the modified region forming step. Since the light-converging point P of laser light L is positioned within the object 1 as depicted, the crack region 9 is formed only within the object 1 . Subsequently, the X-axis stage 109 and Y-axis stage 111 are moved along the line to be cut 5 , so as to form the crack region 9 within the object 1 along the line 5 along which the object is intended to be cut (S 1113 ).
[0519] After the modified region is formed, the crack region 9 is irradiated with the laser light L having for example, wavelength of 1064 nm (YAG laser) along the line 5 along which the object is intended to be cut in the surface 3 of the object 1 again under the same condition (i.e., the light-converging point P is located in the crack region 9 that is a modified region). The laser light L has a transparent characteristics to non-molten processed region of the object, that is, except for the molten processed region of the object, and a high absorption characteristics to the molten processed region comparing with the non-molten processed region. As a consequence, the absorption of laser light L due to scattering by the crack region 9 or the like or the generation of multiphoton absorption in the crack region 9 heats the object 1 along the crack region 9 , thereby generating a stress such as a thermal stress due to a temperature difference (S 1114 ). FIG. 103 is a sectional view of the object 1 including the crack region 9 during laser processing in the stress step. As depicted, the crack is further grown by the stress step while using the crack region 9 as a start point, so as to reach the surface 3 and rear face 21 of the object 1 , thus forming a cut section 10 in the object 1 , whereby the object 1 is cut (S 1115 ). As a consequence, the object 1 is divided into chips.
[0520] Though the eleventh embodiment carries out the same laser light irradiation as that of the modified region forming step in the stress step, it will be sufficient if laser light transmittable through an unmodified region which is a region not formed with a crack region in the object to be processed but more absorbable by the crack region than by the unmodified region is emitted. This is because of the fact that the laser light is hardly absorbed at the surface of the object, whereas the object is heated along the crack region, whereby a stress such as a thermal stress due to a temperature difference occurs in this case as well.
[0521] Though the eleventh embodiment relates to a case where a crack region is formed as the modified region, the same applies to cases where the above-mentioned molten processed region and refractive index change region are formed as the modified region, whereby a stress can occur upon irradiation with laser light in the stress step, so as to generate and grow a crack while using the molten processed region and refractive index change region as a start point and thereby cut the object.
[0522] Even when the crack grown by the stress step while using the modified region as a start point fails to reach the surface and rear face of the object in the case where the object has a large thickness or the like, the object can be broken and cut by applying an artificial force such as a bending stress or shearing stress thereto. This artificial force can be kept smaller, whereby unnecessary fractures deviating from the line to be cut can be prevented from occurring in the surface of the object.
[0523] Effects of the eleventh embodiment will now be explained. In the modified region forming step of this embodiment, the line 5 along which the object is intended to be cut is irradiated with pulse laser light L while locating the light-converging point P within the object to be processed 1 under a condition causing multiphoton absorption. Also, the X-axis stage 109 and Y-axis stage 111 are moved, so as to shift the light-converging point P along the line 5 along which the object is intended to be cut. This forms a modified region (e.g., crack region, molten processed region, or refractive index change region) within the object 1 along the line 5 along which the object is intended to be cut. When an object to be processed has a start point in a part to be cut, the object can be broken and cut with a relatively small force. In the stress step of the eleventh embodiment, the same laser light irradiation as that of the modified region forming step is carried out in the stress step, so as to generate a stress such as a thermal stress due to a temperature difference. As a consequence, the object 1 can be cut by a relatively small force, e.g., a stress such as a thermal stress due to a temperature difference. Therefore, the object 1 can be cut without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut in the surface 3 of the object 1 .
[0524] Since the object 1 is irradiated with the pulse laser light L while locating the light-converging point P within the object 1 under a condition causing multiphoton absorption in the modified region forming step, the pulse laser light L is transmitted there through and is hardly absorbed at the surface 3 of the object 1 in the eleventh embodiment. In the stress step, the same laser light irradiation as that of the modified region forming step is carried out. Therefore, the surface 3 does not incur damages such as melt caused by irradiation with laser light.
[0525] As explained in the foregoing, the eleventh embodiment can cut the object 1 without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut or melt in the surface 3 of the object 1 . Therefore, in the case where the object 1 is a semiconductor wafer, for embodiment, semiconductor chips can be cut out from the semiconductor wafer without generating unnecessary fractures deviating from lines along which the object is intended to be cut or melt in the semiconductor chips. The same holds in objects to be processed having a surface formed with electrode patterns, and those having a surface formed with electronic devices such as piezoelectric device wafers and glass substrates formed with display devices such as liquid crystals. Hence, this embodiment can improve the yield of products (e.g., semiconductor chips, piezoelectric device chips, display devices such as liquid crystals) made by cutting objects to be processed.
[0526] Also, in the eleventh embodiment, the line 5 along which the object is intended to be cut in the surface 3 of the object 1 does not melt, whereby the width of the line 5 along which the object is intended to be cut (which is the gap between regions to become semiconductor chips in the case of a semiconductor wafer, for embodiment) can be reduced. This can increase the number of products prepared from a single object to be processed 1 , and improve the productivity of products.
[0527] Since laser light is used for cutting and processing the object 1 , the eleventh embodiment enables processing more complicated than that in dicing with a diamond cutter. For the eleventh embodiment, cutting and processing can be carried out even when lines 5 along which the object 1 is intended to be cut 5 have a complex form as shown in FIG. 16 also.
[0528] The laser processing method in accordance with the eleventh embodiment according to the present invention can cut an object to be processed without generating melt or unnecessary fractures deviating from the line to be cut in the surface of the object. Therefore, the yield and productivity of products (e.g., semiconductor chips, piezoelectric device chips, and display devices such as liquid crystals) manufactured by cutting objects to be processed can be improved.
[0529] Besides, in the above eleventh embodiments, the crack which is grown from the crack region 9 in the stress step reaches the surface 3 and rear face 21 of the object 1 , but the crack which is grown from the crack region 9 in the stress step the laser light L may be grown so as not to reach the surface 3 and rear face 21 of the object.
Twelfth Embodiment
[0530] The twelve embodiment according to the present invention will now be explained. The laser processing method in accordance with the twelfth embodiment comprises a modified region forming step of forming a modified region caused by multiphoton absorption within an object to be processed, and a stress step of generating a stress at a part where the object is cut, as similar to the eleventh embodiment.
[0531] A laser processing apparatus for the twelfth embodiment is the same as that of the first embodiment as shown in FIG. 14 , and the detailed explanation of the laser processing apparatus is omitted.
[0532] An absorbable laser irradiating apparatus used in the stress step of the twelfth embodiment employs the same configuration as that of the above-mentioned laser processing apparatus 100 as shown in FIG. 14 except for the laser light source and diachronic mirror. The laser light source in the absorbable laser irradiating apparatus uses CO 2 laser with a wavelength of 10.6 μm for generating continuous wave laser light. This is because of the fact that it is absorbable by the object 1 to be processed, which is a Pyrex glass wafer. Alternatively, the laser diode may be used as a light source for generating the absorbable laser light with a wavelength of 808 nm, 14 W as output power and beam size of about 200 μm. The laser light generated by such laser light source has a absorption characteristics to the object 1 and will hereinafter be referred to as “absorbable laser light”. Here, its beam quality is TEM 00 , whereas its polarization characteristic is that of linear polarization. This laser light source has an output of 10 W or less in order to attain such an intensity that the object to be processed 1 is heated but not melted thereby. The diachronic mirror of the absorbable laser irradiating apparatus has a function of reflecting the absorbable laser light, and is arranged so as to change the orientation of the optical axis of absorbable laser light by 90°.
[0533] With reference to FIGS. 14 and 104 , the laser processing method in accordance with the twelfth embodiment will now be explained. FIG. 104 is a flowchart for explaining the laser processing method.
[0534] Steps S 101 , S 103 , S 105 , S 107 , S 109 and S 111 shown in FIG. 104 , are the same as theses shown in FIG. 15 , and therefore, the detailed explanations of the Steps S 101 , S 103 , S 105 , S 107 , S 109 and S 111 are omitted.
[0535] Firstly, as shown in FIG. 104 , steps S 101 and S 103 are executed and next step S 104 is executed. In the step S 104 , the object 1 is mounted on the mounting table 107 of the laser processing apparatus 100 (S 104 ). Next steps S 105 , S 107 , S 109 , and S 111 are executed. After Step 111 of FIG. 104 , laser light L is generated from the laser light source 101 , so as to irradiate the line 5 along which the object is intended to be cut in the surface 3 of the object 1 therewith. FIG. 102 is a sectional view of the object 1 including a crack region 9 during laser processing in the modified region forming step. Since the light-converging point P of laser light L is positioned within the object 1 as depicted, the crack region 9 is formed only within the object 1 . Subsequently, the X-axis stage 109 and Y-axis stage 111 are moved along the line 5 along which the object is intended to be cut, so as to form the crack region 9 within the object 1 along the line 5 along which the object is intended to be cut (S 1213 ).
[0536] After the modified region is formed by the laser processing apparatus 100 , the object 1 is transferred to the mounting table 107 of the absorbable laser irradiating apparatus, so as to be mounted thereon (S 1215 ). The object 1 does not break into pieces, since the crack region 9 in the modified region forming step is formed only therewithin, and thus can easily be transferred.
[0537] The object 1 is illuminated in step 1217 , focal point data for positioning the focal point of visible light from the observation light source at the surface 3 of the object 1 is calculated in step 1219 , and the object 1 is moved in the Z-axis direction so as to position the focal point at the surface 3 of the object 1 in step 1221 , thereby locating the light-converging point of absorbable laser light L 2 at the surface 3 of the object. Here, details of operations in the steps 1217 , 1219 , and 1221 are similar to those of steps 105 , 107 , and 109 in the above-mentioned laser processing apparatus 100 .
[0538] Next, absorbable laser light L 2 is generated from the laser light source of the absorbable laser irradiating apparatus, so as to irradiate the line 5 along which the object is intended to be cut in the surface 3 of the object 1 therewith. Here, the vicinity of the line 5 along which the object is intended to be cut may be irradiated as well. Then, the X-axis stage and Y-axis stage of the absorbable laser irradiating apparatus are moved along the line 5 along which the object is intended to be cut, so as to heat the object 1 along the line 5 along which the object is intended to be cut, thereby generating a stress such as thermal stress caused by a temperature difference at a part where the object 1 is cut along the line 5 along which the object is intended to be cut (S 1223 ). Here, since the absorbable laser has such an intensity that the object 1 is heated but not melted thereby, the surface of the object does not melt.
[0539] FIG. 105 is a sectional view of the object 1 including the crack region 9 during laser processing in the stress step. As depicted, upon irradiation with absorbable laser light, the crack further grows while using the crack region 9 as a start point, so as to reach the surface 3 and rear face 21 of the object 1 , thus forming a cut section 10 in the object 1 , whereby the object 1 is cut (S 1225 ). As a consequence, the object 1 is divided into silicon chips.
[0540] Though the twelfth embodiment relates to a case where a crack region is formed as the modified region, the same applies to cases where the above-mentioned molten processed region and refractive index change region are formed as the modified region, whereby a stress can occur upon irradiation with absorbable laser light, so as to generate and grow a crack while using the molten processed region and refractive index change region as a start point and thereby cut the object.
[0541] Even when the crack grown by the stress step while using the modified region as a start point fails to reach the surface and rear face of the object in the case where the object has a large thickness or the like, the object can be broken and cut by applying an artificial force such as a bending stress or shearing stress thereto. This artificial force can be kept smaller, whereby unnecessary fractures deviating from the line to be cut can be prevented from occurring in the surface of the object.
[0542] Effects of the twelfth embodiment will now be explained. In the modified region forming step of this embodiment, the line 5 along which the object is intended to be cut is irradiated with pulse laser light L while locating the light-converging point P within the object to be processed 1 under a condition causing multiphoton absorption. Also, the X-axis stage 109 and Y-axis stage 111 are moved, so as to shift the light-converging point P along the line 5 along which the object is intended to be cut. This forms a modified region (e.g., crack region, molten processed region, or refractive index change region) within the object 1 along the line 5 along which the object is intended to be cut. When an object to be processed has a start point in a part to be cut, the object can be broken and cut with a relatively small force. In the stress step of this embodiment, the object 1 is irradiated with absorbable laser light along the line 5 along which the object is intended to be cut, so as to generate a stress such as a thermal stress due to a temperature difference. As a consequence, the object 1 can be cut by a relatively small force, e.g., a stress such as a thermal stress due to a temperature difference. Therefore, the object 1 can be cut without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut in the surface 3 of the object 1 .
[0543] Since the object 1 is irradiated with the pulse laser light L while locating the light-converging point P within the object 1 under a condition causing multiphoton absorption in the modified region forming step, the pulse laser light L is transmitted there through and is hardly absorbed at the surface 3 of the object 1 in this embodiment. In the stress step, the absorbable laser light has such an intensity that the object 1 is heated but not melted thereby. Therefore, the surface 3 does not incur damages such as melt caused by irradiation with laser light.
[0544] As explained in the foregoing, this embodiment can cut the object 1 without generating unnecessary fractures deviating from the line 5 along which the object is intended to be cut or melt in the surface 3 of the object 1 . Therefore, in the case where the object 1 is a semiconductor wafer, for embodiment, semiconductor chips can be cut out from the semiconductor wafer without generating unnecessary fractures deviating from lines along which the object is intended to be cut or melt in the semiconductor chips. The same holds in objects to be processed having a surface formed with electrode patterns, and those having a surface formed with electronic devices such as piezoelectric device wafers and glass substrates formed with display devices such as liquid crystals. Hence, this embodiment can improve the yield of products (e.g., semiconductor chips, piezoelectric device chips, display devices such as liquid crystals) made by cutting objects to be processed.
[0545] Also, in this embodiment, the line 5 along which the object is intended to be cut in the surface 3 of the object 1 does not melt, whereby the width of the line 5 along which the object is intended to be cut (which is the gap between regions to become semiconductor chips in the case of a semiconductor wafer, for embodiment) can be reduced. This can increase the number of products prepared from a single object to be processed 1 , and improve the productivity of products.
[0546] Since laser light is used for cutting and processing the object 1 , this embodiment enables processing more complicated than that in dicing with a diamond cutter. For embodiment, cutting and processing can be carried out even when line 5 along which the object is intended to be cut have a complex form as shown in FIG. 16 .
[0547] The laser processing method of the twelfth embodiment according to the present invention can cut an object to be processed without generating melt or unnecessary fractures deviating from the line to be cut in the surface of the object. Therefore, the yield and productivity of products (e.g., semiconductor chips, piezoelectric device chips, and display devices such as liquid crystals) manufactured by cutting objects to be processed can be improved.
[0548] Besides, in the above eleventh embodiments, the crack which is grown from the crack region 9 in the stress step reaches the surface 3 and rear face 21 of the object 1 , but the crack which is grown from the crack region 9 in the stress step the laser light L may be grown so as not to reach the surface 3 and rear face 21 of the object.
Thirteenth Embodiment
[0549] The thirteenth embodiment according to the present invention will now be explained. The laser processing method in accordance with the thirteenth embodiment comprises attaching step of adhesively attaching an object to be processed to an adhesive and expansive sheet, a modified region forming step of forming a modified region in the object, and cutting/separation step of cutting the object at the modified region thereof and separating the cut parts of the object so as to make the space there between.
[0550] The above modified region forming step of the thirteenth embodiments may be any one of the first to twelfth embodiments stated above. Further, in the modified region forming step, the object may be cut at the modified region. In this case that the object is cut at the modified region in the modified region forming step, in the separation step, the cut parts of the object are spaced to each other by a predetermined distance by expansion of the adhesive and expansion sheet. Alternatively, when in the modified region forming step, although the modified region is formed in the body as a molten processed region, the object is not cut, in the separation step, the object is cut and the cut parts of the object are separated to each other with a predetermined space therebetween.
[0551] FIG. 106 shows a film expansion apparatus 200 and the apparatus 200 has a ring shape holder 201 and a column like expander 203 . The adhesive and expansive sheet on which the object to be cut is attached is set to the ring shape holder 201 . After setting of the adhesive and expansive sheet 204 on the ring shape holder 201 at peripheral edge of the sheet, the modified region is formed in the object along a line along which the object is intended to be cut. After the formation of the modified region in the object, the column like expander 203 is moved up against the adhesive and expansive sheet 204 so that a part of the sheet is pushed upward as shown in FIG. 107 . The movement of the part of the sheet 204 causes the expansion of the sheet along a lateral direction thereof so that the sheet 204 is expanded as shown in FIG. 107 . As the result of the expansion of the sheet 204 , the parts of the object which is cut in the modified region forming step are separated to each other with a predetermined space therebetween. So, the pick up of the parts of the object from the adhesive and expansive sheet 204 is performed easily and surely.
[0000] When the object is not cut in the modified region formation step, the expansion of the sheet 204 caused by the upward movement of the expander 203 causes the separation of the object into parts of the object in the modified region and thereafter the cut parts of the object are separated to each other with a predetermined space therebetween.
[0552] The laser processing method and apparatus in accordance with the present invention can cut an object to be processed without generating melt or fractures deviating from lines along which the object is intended to be cut on a surface of the object. Therefore, the yield and productivity of products (e.g., semiconductor chips, piezoelectric device chips, and display devices such as liquid crystal) prepared by cutting objects to be processed can be improved.
[0553] The basic Japanese Application No. 2000-278306 filed on Sep. 13, 2000 and No. 2001-278768 filed on Sep. 13, 2001 and PCT Application No. PCT/JP01/07954 filed on Sep. 13, 2001 are hereby incorporated by reference.
[0554] From the invention thus described, it will be obvious that the embodiments of the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims. | A laser beam machining method and a laser beam machining device capable of cutting a work without producing a fusing and a cracking out of a predetermined cutting line on the surface of the work, wherein a pulse laser beam is radiated on the predetermined cut line on the surface of the work under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the work, and a modified area is formed inside the work along the predetermined determined cut line by moving the condensed point along the predetermined cut line, whereby the work can be cut with a rather small force by cracking the work along the predetermined cut line starting from the modified area and, because the pulse laser beam radiated is not almost absorbed onto the surface of the work, the surface is not fused even if the modified area is formed. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. §119 (e) of the U.S. Provisional Patent Application Ser. No. 61/241,317 filed on Sep. 10, 2009.
FIELD OF THE INVENTION
[0002] This application relates to the field of oilfield equipment and more specifically to a Rotating Control Device (RCD) and Cool Fluid Circulation System (CFCS) for managing drilling fluid composition and temperature across the interface of an RCD insert.
BACKGROUND OF THE INVENTION
[0003] As is known, in managed pressure applications, there is a need to dynamically and effectively control fluid pressure within a wellbore during drilling. More specifically, it is important to maintain drilling fluid in a wellbore at a pressure less than or equal to the fluid pressure of a geological formation in order to prevent drilling related problems such as stuck pipes, loss of circulation and excessive use of drilling mud.
[0004] Drilling fluid is required during drilling operations to lubricate the drill bit and carry drill cuttings to the surface. Typically, drilling fluid is pumped downwardly through the drill pipe to the drill bit whereupon it returns upwardly to the surface through the wellbore annulus. Drilling fluid returning to the surface will be affected by gravity and friction encountered along the walls of the wellbore thereby increasing the hydrostatic pressure at the bottom of the wellbore.
[0005] Managed Pressure Drilling (MPD) is an adaptive drilling process used to precisely control the annular pressure profile throughout a wellbore. More specifically, MPD allows bottom hole pressure adjustments with minimal interruptions to the drilling process. The annular pressure profile is controlled such that it is balanced or nearly balanced. The objective of MPD is to ascertain the downhole pressure environment limits and to manage the annular hydraulic pressure profile accordingly.
[0006] MPD uses a closed, pressurizable fluid system to control the annular pressure profile. More specifically, the annular pressure in the wellbore is controlled through adjustments in backpressure, fluid density, fluid rheology, annular fluid level, circulating geometry, hole geometry or the like.
[0007] Similarly, Underbalanced Drilling (UBD) uses a closed and pressurizable fluid system wherein the annular wellbore pressure profile is less than the fluid pressure in the formation being drilled. Annular pressure in the wellbore is similarly controlled through adjustments in backpressure, fluid density, fluid rheology, annular fluid level, circulating geometry, hole geometry and the like.
[0008] In order to prevent drilling related problems as described above, MPD and UBD decrease the Equivalent Circulating Density (ECD) by lowering the hydrostatic pressure of drilling fluid. A low density drilling fluid can mitigate the risk of a well becoming overbalanced and developing drilling problems. A gas is often injected into a drilling fluid in order to reduce the drilling fluid density. Some gases commonly used for drilling fluid injection include air, nitrogen, natural gas and processed flue gas. As is known, the use of natural gas and/or processed flue gas may increase the combustible and/or corrosive nature of the drilling fluid.
[0009] Furthermore, in MPD and UBD, drilling fluid is naturally heated while traveling to and from the drill bit by the drilling process and/or geological formations. As a result, drilling fluid often reaches temperatures greater than 65 degrees Celsius (149 degrees Fahrenheit) and can exceed 85 degrees Celsius (185 degrees Fahrenheit). Furthermore, drilling fluid may be comprised of or accumulate combustible and corrosive components during the drilling process.
[0010] As in other drilling operations, managed pressure and underbalanced drilling require a Blowout Preventer (BOP) to prevent an uncontrolled release of formation fluids from the wellbore. A release may cause significant damage to a drilling rig and injuries or fatalities to rig personnel. As a result, MPD and UBD further require that a Rotating Control Device (RCD) be installed on the top of the BOP stack to form a positive pressure seal on the drill pipe and safely divert drilling fluid away from the drill floor. An RCD typically contains a radial insert that forms a seal around the drill pipe.
[0011] As is known, RCD inserts are generally radial and fabricated from synthetic rubber such as neoprene or nitrile rubber. During drilling, the drill pipe is axially forced downwards through the RCD and RCD insert such that over time the RCD insert will incur wear and tear as the insert slidably engages the drill pipe. Thus, as a result of normal use, RCD inserts will deteriorate and become less effective over time. Furthermore, in particular, high temperature drilling fluid and/or any corrosive components of a drilling fluid will accelerate the deterioration of an RCD insert.
[0012] An RCD insert manufacturer will typically recommend a maximum operating lifetime before which RCD inserts should be replaced to ensure safe and productive operation of a drilling rig. The replacement of an RCD insert requires considerable Non Productive Time (NPT) as the drill string must be broken and the RCD disassembled. Accordingly, there continues to be a need for systems that can increase the time between RCD insert replacements.
[0013] As noted, temperature and/or corrosive drilling fluid may cause accelerated deterioration of an RCD insert such that the accelerated deterioration of an RCD insert may cause the premature and/or unexpected failure of the insert before the expiration of the manufacturer recommended maximum operating lifetime. Any premature or unexpected failure can present a significant safety risk to personnel if drilling fluid is released onto the drill floor.
[0014] Thus, while RCD inserts are currently manufactured to resist the corrosive chemical properties or high temperatures of returned drilling fluid, RCD inserts are generally not designed to resist the combination of both the corrosive chemical properties and high temperatures of returned drilling fluids found in many drilling operations.
[0015] More specifically, as is known to one of skill in the art, RCD inserts are generally designed to perform specifically to a recommended maximum operating temperature (typically 65-85° C.). Increases in temperature and/or corrosive drilling fluid compositions can decrease the operating lifetime of an RCD insert. Thus, the maximum operating lifetime of an RCD insert can be extended (and the risk of premature failure reduced) by decreasing the temperature of returned drilling fluid at the RCD insert/drilling fluid interface and/or moderating the composition of returned drilling fluid coming into contact with the RCD insert.
[0016] It is therefore an object of the present invention to improve the useful life of an RCD insert by providing a system and method for lowering the temperature and moderating the composition of returned drilling fluid coming into contact with an RCD insert within an RCD.
[0017] A review of the prior art reveals that a number of technologies have been used in the past for cooling inserts in a Rotating Control Device. For example US Patent Publications 2006/0144622 and 2008/0210471 to Bailey et al. disclose Rotating Control Devices (RCDs) having thermal transfer systems for circulating cooling fluid inside radial RCD seals.
[0018] U.S. Pat. Nos. 6,749,172 and 7,004,444 to Kinder disclose Rotating Control Devices (RCDs) having two independent fluid circuits for cooling and lubrication between a rotating body and the RCD casing.
[0019] Other references include U.S. Pat. No. 5,662,181 which describes circulating chilled water or antifreeze through the top seal packing box of an RCD and U.S. Pat. No. 5,277,249 which describes an RCD having a heat exchanger and fluid circuits for cooling radial seals in a packer assembly.
[0020] While the prior art may provide a partial solution, each are limited in various ways as briefly described below.
[0021] In particular, past systems may be limited as they do not suggest or teach the advantages of a cooling system in which the cooling fluid is in direct contact with the hot drilling fluid. More specifically, previous systems do not suggest a system to prevent hot drilling fluid from directly contacting the radial RCD inserts. Furthermore, previous systems do not teach moderating the composition of drilling fluid across the interface of a radial RCD insert.
SUMMARY OF THE INVENTION
[0022] It is the object of the present invention to obviate or mitigate at least one disadvantage of previous rotating control devices and specifically to provide systems and methods that enhance the operating life of an RCD insert within an RCD.
[0023] In accordance with a first embodiment of the invention, there is provided a cool fluid circulation system (CFCS) for circulating cool drilling fluid across a rotating control device (RCD) and RCD insert operatively connected to a well head having a hot drilling fluid return outlet, the CFCS comprising: a body for operative connection between the RCD and the hot drilling fluid return outlet at the well head, the body including an inlet for injecting cool drilling fluid adjacent the RCD insert and an outlet for removing partially warmed drilling fluid; wherein the cool drilling fluid is in direct contact with hot drilling fluid in a buffer zone adjacent the hot drilling fluid return outlet.
[0024] In further embodiments, the CFCS includes a void space above the inlet and outlet for containing and circulating a volume of cool drilling fluid adjacent the RCD insert and/or a second void space below the inlet and outlet for containing and circulating a volume of cool drilling fluid adjacent an interface with hot drilling fluid.
[0025] In another embodiment, the invention provides a system for circulating cool drilling fluid across a rotating control device (RCD) and RCD insert operatively connected to a well head having a hot drilling fluid return outlet, the CFCS comprising: a body for operative connection between the RCD and the hot drilling fluid return outlet at the well head, the body including an inlet for injecting cool drilling fluid adjacent the RCD insert and an outlet for removing partially warmed drilling fluid; wherein the cool drilling fluid is in direct contact with hot drilling fluid adjacent the hot drilling fluid return outlet; and, a cool drilling fluid circulation system operatively connected to the inlet for injecting cool drilling fluid into the inlet and for removing partially warmed drilling fluid from the outlet.
[0026] In a further embodiment, the system includes a choke system for controlling the flow rate and pressure of cool drilling fluid within the cool drilling fluid circulation system and will preferably include at least one temperature sensor operatively connected to the body for measuring the temperature of cool drilling fluid within the body and/or at least one pressure sensor operatively connected to the body for measuring the pressure of cool drilling fluid within the body.
[0027] In a further embodiment, the system includes a control system operatively connected to the temperature sensor and pressure sensor for automatically controlling the flow rate of cool drilling fluid within the cool drilling fluid circulation system in response to measured temperatures and pressures in the cool drilling fluid circulation system.
[0028] In another aspect, a method is described for circulating cool drilling fluid across a rotating control device (RCD) having an RCD inlet and an RCD outlet and RCD insert, the RCD operatively connected to a well head having a hot drilling fluid return outlet, the method comprising the step of: circulating a volume of cool drilling fluid adjacent the RCD insert through the RCD inlet and outlet wherein the cool drilling fluid is in direct contact with hot drilling fluid adjacent the hot drilling fluid return outlet.
[0029] In further embodiments of the method, the cool drilling fluid recovered from the RCD outlet is subjected to a cooling process prior to recirculating cool drilling fluid into the RCD inlet.
[0030] In yet another embodiment, the cool drilling fluid recovered from the RCD outlet is subjected to a solids separation process prior to recirculating cool drilling fluid into the RCD inlet.
[0031] In yet another embodiment, the temperature of the cool drilling fluid recovered from the RCD outlet is monitored and the flow rate of the cool drilling fluid is adjusted through the RCD to ensure adequate cooling of the RCD insert.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The invention is described with reference to the accompanying figures in which:
[0033] FIG. 1 is a cross sectional view of a Rotating Control Device and Cool Fluid Circulation System (CFCS) having a cool drilling fluid inlet and outlet in accordance with one embodiment of the invention.
[0034] FIG. 2 is a schematic diagram of a primary circulation system and cool drilling fluids circulation system in accordance with one embodiment of the invention; and,
[0035] FIG. 3 is a schematic representation of a decision making process for controlling the pressure of cool drilling fluid in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] As used herein, the term “returned drilling fluid” 30 refers to all fluids, solids and gases in a drilling operation that have been returned to the surface through a wellbore 40 including drilling fluid, drill cuttings, oil and the like.
[0037] Overview
[0038] With reference to the figures, the present invention generally relates to a system enabling the circulation of cool drilling fluid through a Rotating Control Device (RCD) 10 and RCD insert 14 . The device and its control system are particularly useful in managed pressure or underbalanced well drilling.
[0039] As known, an RCD 10 and RCD insert 14 generally seals around and rotates with a drill pipe 24 to prevent drilling fluid circulating through the annulus from escaping onto the drill floor. In addition, the RCD 10 and RCD insert 14 permits the drill pipe 24 to slide into and out of the wellbore while maintaining a tight seal on the drill pipe 24 . Within known systems, a main drilling fluid outlet 28 at the well head allows drilling fluid to be removed from the annulus of the well for drill cutting removal and re-use. In various applications, a well incorporating an RCD may include other systems for enhancing the hydraulic pressure seal and/or to provide other functions to and around a drill pipe 24 as known to those skilled in the art.
[0040] In accordance with the invention, the RCD further includes a cool fluid circulation system (CFCS) 15 for operative connection between the RCD and main drilling fluid outlet 28 of the well. The CFCS 15 includes a cool drilling fluid inlet 18 and cool drilling fluid outlet 20 that enables the circulation of cool drilling fluid 16 across the lower surfaces of the RCD insert 14 and within an RCD cavity 22 . In accordance with the objects of the present invention, the circulation of cool drilling fluid 16 across the lower surfaces of the RCD insert 14 lowers the temperature and moderates the composition of drilling fluid in the RCD cavity 22 thereby slowing the deterioration of the RCD insert 14 . As a result, the present invention will increase the maximum operating lifetime and mitigate the risk of premature failure of an RCD insert 14 .
[0041] In addition, the present invention further includes external fluid circuits for circulating drilling fluids and cool drilling fluids ( FIG. 2 ). A first drilling fluid circuit 400 withdraws returned drilling fluid from the wellbore and inserts recycled drilling fluid down the drill pipe 24 . A second drilling fluid circuit 200 circulates cool drilling fluid 16 across the interface of the RCD insert within the rotating control device 10 . A control system 500 monitors the circulation of drilling fluids ( FIG. 3 ).
[0042] Rotating Control Device and Cool Fluid Circulation System
[0043] FIG. 1 generally describes an RCD 10 which as known to those skilled in the art includes a body 12 and a bearing assembly (not shown) retained within the body 12 that rotates with drill pipe 24 and that operatively supports the RCD insert. The bearing assembly is operationally located between the RCD body 12 and a drill pipe 24 so as to permit rotational movement of the RCD insert with respect to the body. As known, the drill pipe 24 will pass through the top of the RCD body 12 , RCD insert 14 and into the wellbore.
[0044] As shown in FIGS. 1 and 2 , returned drilling fluid 30 flowing upwardly within the annular column 12 a is withdrawn through an outlet 28 into a first fluid circuit 400 . During Managed Pressure or Underbalanced drilling that does not include a CFCS 15 , the returned drilling fluid 30 fills the RCD cavity 22 and is in direct contact with the RCD insert 14 .
[0045] In accordance with the invention, the CFCS 15 includes a cool drilling fluid inlet 18 and cool drilling fluid outlet 20 operationally connected to the RCD below the RCD insert 14 . Both the inlet 18 and outlet 20 are connected to the cool drilling fluid circulation system 200 . The inlet 18 and outlet 20 are diametrically opposite each other and are located above the returned drilling fluid outlet 28 in the annulus 12 a.
[0046] In operation, cool drilling fluid 16 enters the CFCS through the cool drilling fluid inlet 18 to create a buffer zone 22 a of cool drilling fluid between the returned drilling fluid and the RCD insert. The inlet 18 is positioned to generally direct cool drilling fluid 16 across the interface of the RCD insert 14 such that the buffer zone 22 a prevents returned drilling fluid 30 from directly contacting the RCD insert 14 . A cool drilling fluid outlet 20 is positioned opposite to the inlet 18 in order to withdraw cool drilling fluid 16 from the buffer zone and RCD cavity 22 .
[0047] Importantly, the temperature and pressure of drilling fluid within the buffer zone 22 a can be controlled and any abrasive or corrosive components of returned drilling fluid 30 will be substantially prevented from contacting the RCD insert 14 . In other words, the combined design of the RCD 10 , the CFCS 15 and the operational temperature and pressure of cool drilling fluid 16 are designed and controlled to prevent substantive mixing and diffusion of returned drilling fluid 30 into the RCD cavity 22 so as to provide maximum cooling and fluid composition moderation across the lower surfaces of the RCD insert.
[0048] Primary Drilling Fluid Circulation System and Cool Fluids Circulation System
[0049] With reference to FIG. 2 , the invention further provides a system enabling the use of the CFCS within a drilling operation. The system includes a primary drilling fluids circulation system 400 and a cool fluids circulation system 200 for operative connection to the CFCS.
[0050] The primary drilling fluids circulation system (primary fluid circuit) 400 enables downhole pumping of drilling fluid, surface recovery of returned drilling fluid, surface cleaning and separation of returned drilling fluid, chemical modification of drilling fluid and re-circulation of returned drilling fluid 30 . Within the primary fluid circuit, drilling fluids are pumped down the drill pipe to the drill bit, and returned upwardly to the surface between the drill pipe and wellbore 40 where the returned drilling fluid is withdrawn through the annular outlet 28 . At surface, the primary fluid circuit 400 includes piping 420 , storage tanks 402 and pumps 404 as required for the operation of the primary fluid circuit 400 .
[0051] In addition, as it is desirable to remove undesirable components such as drill cuttings and oil from the returned drilling fluid 30 before the recirculation of drilling fluid down the drill pipe 24 , the primary fluid circuit 400 will typically include a separation system 418 for removing drill cuttings, oil and other contaminants from the returned drilling fluid 30 . The separation system may include components such as a shale shaker, sedimentation tanks, chemical processing, and/or cleaning systems and the like in order that clean drilling fluid 30 is reused and pumped down the drill pipe 24 .
[0052] The primary fluid circuit 400 will further include appropriate manifolds 416 , valves 406 and choking devices 412 to enable control of the pressure and flow of drilling fluid 30 and/or chemical injection/adjustment within the system. Other systems may include gas injection 430 as well as standard well kill systems including pump 432 and kill mud tanks 432 a.
[0053] The primary fluid circuit will also include appropriate temperature 422 and pressure sensors 424 to monitor drilling fluid properties.
[0054] The cooling fluid circulation system (cool fluid circuit) 200 is provided to insert cool drilling fluid 16 into the cool drilling fluid inlet 18 and withdraw drilling fluid from cool drilling fluid outlet 20 . The cool fluid circuit 200 includes piping 220 , a fluids handling system operating in conjunction with the separation system 418 and appropriate pumps 204 as required for the operation of the cooling fluid circulation system. Appropriate valves 206 are also provided to stop or redirect cool drilling fluid 16 flow as may be desired within a specific system.
[0055] Operation
[0056] Generally, in operation, in order to provide effective RCD insert cooling, it is necessary to balance the pressure and flow rate of cool drilling fluid 16 circulating in the RCD cavity. For example, insufficient cool drilling fluid 16 pressure and flow would generally cause the temperature of RCD insert 14 to rise whereas conversely, high pressure cool drilling fluid 16 may cause undesirable mixing and diffusion between the cool drilling fluid 16 and the returned drilling fluid 30 .
[0057] As a result, as the pressure of returned drilling fluid 30 may change over time, a choking device 212 may be installed downstream of the RCD outlet 20 in order to control the pressure of cool drilling fluid 16 within the RCD. Choking device 212 can be adjusted to increase or decrease the flow of cool drilling fluid 16 as required to maintain a desired pressure and flow of cool drilling fluid within the RCD cavity 22 .
[0058] The cool fluid circuit 200 may further include appropriate sensors to monitor drilling fluid 16 characteristics such as the temperature and pressure within the circuit. In a preferred embodiment, temperature 208 and pressure 210 sensors are located at the cool drilling fluid inlet 18 and outlet 20 to the RCD 10 . The system will also preferably include emergency release piping 420 to enable effective diversion in the event of an emergency as well as equalization and bleed-off piping 600 as known to those skilled in the art.
[0059] In another embodiment, the cooling fluid circulation system 200 may include a refrigeration system (not shown) for actively or passively cooling drilling fluids.
[0060] Control System
[0061] The RCD, primary fluid circuit 400 and cooling fluid circulation system 200 may be monitored and controlled by a control system 500 . In a preferred embodiment, the control system 500 is electronic and operationally connected to appropriate temperature sensors 214 , 424 , pressure sensors 216 , 426 , valves 206 , 406 and choking devices 212 , 412 in order to enable effective control of the system during drilling.
[0062] In one embodiment, temperature and pressure sensors operationally transmit temperature and pressure data to the control system. The control system may decide to increase or decrease fluid pressure within the primary fluid circuit 400 or cooling fluid circulation system 200 as required for drilling and the optimal operation of the RCD 10 and CFCS 15 . More specifically, the control system may instruct a choking device 212 , 412 to increase or decrease fluid pressure in the desired fluid circuit.
[0063] Referring to FIG. 3 , a preferred embodiment of a control decision structure is provided. By way of example, the electronic interface may take a temperature reading at the RCD outlet 502 and determine if the temperature is too high 506 . If the temperature is too high, the control system will take steps to increase cool drilling fluid pressure 510 . Increased cool drilling fluid pressure may be provided by closing a choking device 212 or increasing pump pressure 204 . Conversely, if the temperature reading at the outlet 502 is not too high, the control system will evaluate if the pressure reading at the RCD outlet 504 is too high 508 . If the pressure reading 504 at the outlet is too high, the control system will reduce the pressure of cool drilling fluid 512 . If the pressure is not too high, no adjustments will be made by the control system 514 .
[0064] Similar embodiments can be realized by alternate positioning of sensors and control decision structures.
[0065] Although the present invention has been described and illustrated with respect to preferred embodiments and preferred uses thereof, it is not to be so limited since modifications and changes can be made therein which are within the full, intended scope of the invention as understood by those skilled in the art. | Systems and methods for cooling a Rotating Control Device (RCD) and RCD insert during drilling operations are described. The system includes a body for connection between the RCD and a hot drilling fluid return outlet of a well head, the body including an inlet for injecting cool drilling fluid adjacent the RCD insert and an outlet for removing partially warmed drilling fluid. During operation, cool drilling fluid is circulated through the inlet and outlet such that cool drilling fluid is in direct contact with hot drilling fluid recovered from the well in a buffer zone adjacent the hot drilling fluid return outlet. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an improved optical arrangement for performing traceable null testing of aspheric surfaces and, in particular, relates to one such arrangement using reflective/diffractive optics.
2. Description of the Prior Art
Prior art arrangements of null testing optical components have included the use of refractive null lenses. The use of such lenses in a null testing optical arrangement results in a null testing system which is difficult to qualify because accurate knowledge of all of the lens construction parameters, such as radius of curvature, thickness, centering, surface form, material refractive index and homogeneity, is needed. The use of refracting null lenses in null testing optical arrangements also requires that the refractive lens be made from a good specimen of optical glass having well known optical properties.
The use of a diamond turned (kinoform) reflective/diffractive null optical component in the arrangement of the present invention overcomes the above identified problems associated with the qualification of the refractive lens null optical component used in prior art null testing optical arrangements. Also, the improved null testing optical arrangement of the present invention avoids the use of optical materials in the transmission of light and allows the diffractive null testing technique to be immune to homogeneity variations.
Consequently, it is highly desirable to provide an improved null test optical arrangement that overcomes the above recited drawbacks of the prior art null testing optical arrangements using conventional null testing components.
SUMMARY OF THE INVENTION
The present invention contemplates an improved null testing optical arrangement for measuring aspheric surfaces. The improved null testing optical arrangement includes a reflective/diffractive (kinoform) optic having a first surface, a second surface that is both reflective and diffractive, and an aperture between the first and second surfaces. The improved null testing optical arrangement also includes a light transmitting/receiving means positioned adjacent to the first side of the reflective/diffractive (kinoform) optic and proximal to the aperture. The improved null testing optical arrangement further includes an interferometer positioned proximal to the light transmitting/receiving means so as to transmit light to the light transmitting/receiving means. The interferometer initiates a test light wavefront and analyzes a return light wavefront received by the light transmitting/receiving means from the reflective/diffractive (kinoform) optic and aspheric optic work piece.
The present invention also contemplates a method for null testing an optical work piece having an aspheric surface thereon with the improved reflective/diffractive null testing optical arrangement. The method comprises positioning the reflective/diffractive optic a predetermined distance from the aspheric surface of the optical work piece, wherein the second surface of the reflective/diffractive optic is oriented so as to face the aspheric surface of the optical work piece. Light is transmitted from the interferometer towards the light transmitting/receiving means. The light received by the transmitting/receiving means is passed through the aperture towards the aspheric optical work piece to cause the light to be reflected by the aspheric surface of the aspheric optical work piece onto the second surface of the reflective/diffractive (kinoform) optic. The light is further reflected by the second surface of the reflective/diffractive (kinoform) optic onto the aspheric surface of the optical work piece. The light is finally reflected by the aspheric surface of the optical work piece through the aperture and onto the light transmission/receiving means. The light is finally transmitted by the light transmission/receiving means to the interferometer where the interference pattern of the multiple reflected light is analyzed.
Accordingly it is one object of the present invention to provide an improved null testing optical arrangement for performing traceable null testing of aspheric surfaces.
Another object of the present invention is to provide a method for traceable null testing of an aspheric surface.
These objects are accomplished, at least in part, by an improved optical arrangement for performing traceable null testing of aspheric surfaces using reflective/diffractive optics.
Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description read in conjunction with the attached drawings and claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings, not drawn to scale, include:
FIG. 1 is a schematic diagram illustrating the use of a refractive lens null optical component in a prior art null testing optical arrangement to test a concave mirror;
FIG. 2 is a schematic diagram illustrating the use of a plane aluminum reflective surface null optical component in a prior art null testing optical arrangement to test the same concave mirror;
FIG. 3 is a graph of a typical wavefront error for the concave mirror as tested by the prior art null testing arrangements illustrated in FIGS. 1 and 2;
FIG. 4 is a schematic diagram illustrating the use of a diamond turned reflective/diffractive (kinoform) optical component in the null testing optical arrangement embodying the principles of the present invention;
FIG. 5 is a graph of residual wavefront error achieved with the reflective/diffractive null testing optical arrangement of FIG. 4.
FIG. 6 is a view of the reflective/diffractive second side of the reflective/diffractive null optic;
FIG. 7 is a view of a section (not to scale) of the reflective/diffractive null optic illustrating the diffraction grating turned therein.
FIG. 8 is a sectional view of FIG. 7, illustrating a typical profile for the diffraction grating.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the use of a refractive lens 10 null optic in a prior art null testing optical arrangement 12 for testing the surface of concave mirror 14. FIG. 2 illustrates the use of a plane reflective mirror 16 null optic having an aperture 17 in another prior art null testing optical arrangement 18 for testing the surface of concave mirror 14. With the prior art null testing optical arrangements shown in FIGS. 1 and 2, null testing is typically performed by constructing the optical system to be tested within the system's design tolerances followed by testing the system with a commercial interferometer. A typical wavefront aberration for concave mirror 14 for light at a wave length of 633 nm is shown graphically in terms of wavefront aberration (waves) versus pupil radius (inches) in FIG. 3.
Referring to FIGS. 4, 6, 7 and 8, the arrangement 22 of the present invention includes a reflective/diffractive null optic 24 having a first surface 28, a reflective/diffractive disposed on a second surface 30 thereof, and an aperture 32 therebetween where light from a light source can pass through. FIGS. 6, 7 and 8 illustrate a portion 33 of a diffraction pattern 35 of the reflective/diffractive surface 30 that comprises a series of concentric facet surfaces 37. In a preferred embodiment, the null optic 24 is made from aluminum and the concentric facet surfaces 37 are formed by well known diamond cutting apparatus and techniques. As will be appreciated by those skilled in the art, other reflective materials may be used without departing from the scope of the present invention.
In another preferred embodiment, the aperture 32 is substantially central in the surfaces, 28 and 30. While the aperture 32 need only be a size convenient to admit light therethrough, the aperture should be kept small because a portion of the test pattern is lost by the aperture. In practice, an aperture 32 approximately 5 mm in diameter has been found to perform satisfactorily.
As shown in FIG. 4, the arrangement 22 of the present invention also includes an interferometer 42 and a light transmitter/receiver 44. Any well known commercial interferometer may be used as the interferometer 42 and the light transmitter/receiver 44 may be any well known apparatus for transmitting light such as a highly corrected lens supplied with a commercial interferometer or a light transmission sphere. The arrangement 22 also includes a wavefront analyzer 46. A commercially available computer may be used as the wavefront analyzer 46.
Now referring to FIG. 4, the reflective/diffractive optic 24 is used in the null testing arrangement 22 of the present invention by positioning the optic 24 in front of the concave mirror 14 to be tested so that the second surface 30 having the diamond turned diffraction pattern thereon faces the reflective surface 36 of concave mirror 14. The optic 24 is positioned at its design distance d from the reflective surface 38 of the concave test mirror 14. The design distance d is in the vicinity of the focus of the test mirror. The interferometer 42 and light transmitter/receiver 44 are positioned adjacent to the first surface 28 of the optic 24. A light wavefront from the interferometer 42 is focused through the light transmitter/receiver 44 so that it passes the light wavefront through the aperture 32. The light wavefront passing through the aperture 32 is initially reflected off of the concave test mirror 14 onto the reflective/diffractive surface 30 of the reflective/diffractive optic 24. The wavefront is then reflected by the reflective/diffractive surface 30 back onto the concave mirror 14 where a second reflection causes the light wavefront to pass back through aperture 32, through the light transmitter/receiver 44 and through the interferometer 42. The mirror 14 is characterized by analyzing the wavefront of the light returning through the interferometer 42 with analyzer 46.
The reflection of the wavefront from the reflective/diffractive surface 30 of optic 24 generates a reference wavefront that can be completely characterized by measuring the diameters of diffractive rings on the second surface of the optic 24. This reference wavefront allows the reflective surface 36 of mirror 14 to be analyzed because the diffraction pattern on the reflective/diffractive surface 30 of optic 24 cancels the aspheric components of the wavefront thus allowing analysis by the interferometer 42.
FIG. 5 graphically illustrates a residual wavefront aberration in terms of wavefront aberration (waves) versus pupil radius (inches) of the aperture 32 of optic 24 typically measured with the null testing optical arrangement 22 of the present invention with light at a wavelength of 633 nm.
Thus, with the present invention now fully described, it can be seen that the objectives set forth above are efficiently attained and since certain changes may be made in the above-described device without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Hence the present invention is deemed limited only by the appended claims and the reasonable interpretation thereof. | An improved null optical testing arrangement (22) for null testing aspheric surfaces of optics includes a reflective/diffractive null optical component (24). The reflective/diffractive null optical component (24) provides a reflective/diffractive surface (30) that is easily qualified as a null testing optical arrangement. The reflective/diffractive surface (30) of the null optic (24) generates a reference wavefront which can be completely characterized by measuring the diameters of diffractive rings with an interferometer (42). | 6 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates generally to a liquid supply system, and more specifically, it relates to a system for supplying a liquid at a substantially constant pressure.
While the following description relates primarily to a domestic water supply system, it will be apparent that the invention is also applicable to other types of liquid supply systems.
A domestic water supply system in common use includes a motor-pump unit located in a water well, the unit being suspended by a pipe which also conveys the pumped water to the house. At the surface, the system further includes a storage-pressure tank which receives the pumped water and is connected to the plumbing of the house. A water pressure actuated switch is mounted adjacent to the tank through which electric power is supplied to the motor. Hysteresis in the operation point of this switch establishes an operating pressure range for the tank and water supply system. The electric motor is a constant speed type and the pump is usually a centrifugal type. The storage tank is relatively large (usually about 15 to 30 gallons) and stores a sizable amount of water, so that the motor does not have to be turned on and off frequently.
Systems similar to the foregoing have included a jet pump in place of the centrifugal pump, and this arrangement is useful with relatively small diameter pipes. However, jet pumps are usually avoided because they have a lower efficiency than centrifugal pumps.
Another type of water supply system includes a variable speed motor and a centrifugal pump. The power supply for the motor includes a DC link electronic package which varies the motor speed in response to the water pressure. In another type of system, an electronic package is part of the motor-pump unit so that the heat-generating electronic package may be cooled by the well water. Systems including a pressure sensor and a variable speed motor and designed to supply water at a substantially constant pressure have also been provided. Such systems have been used as pressure boosters in relatively tall buildings in some areas (usually outside the United States).
It is a general object of the present invention to provide a system for supplying a liquid at a substantially constant pressure which is an improvement over the foregoing systems.
SUMMARY OF THE INVENTION
This invention relates to a liquid supply system including a motor-pump unit designed for installation in a liquid supply such as a well or storage tank. The unit supplies the liquid to a supply pipe, and the invention further comprises a pressure sensor connected to the pipe and operable to provide a control signal representative of the liquid pressure in the pipe. The motor is a variable-speed AC motor, and the invention still further comprises a control for the motor, the control being responsive to the control signal and actuating a power circuit to drive the motor at a speed selected to maintain the liquid pressure at a substantially constant value. The control circuit includes means for turning off the power to the motor in the absence of flow through pipe, which does not require a flow sensor. The power circuit comprises a DC link including a rectifier and an inverter. The rectifier is located adjacent the pressure sensor; the inverter may be located adjacent the rectifier and the pressure sensor or in the casing of the motor-pump unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a liquid supply system embodying the invention;
FIG. 2 is a block diagram of a control circuit of the system shown in FIG. 1;
FIG. 3 is a block diagram of a power circuit of the system shown in FIG. 1; and
FIG. 4 is an illustration of an alternative embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a liquid supply system, in accordance with the invention. An underground storage tank 11 contains a liquid 12 to be pumped at a substantially constant pressure, and a motor-pump unit 13 is mounted in the tank 11. While FIG. 1 shows a closed tank, it may instead be another type of reservoir such as a well. The unit 13 includes an electric motor 14 and a pump 15 which, when driven by the motor 14, pumps the liquid through a pipe 16, and a pressure tank or accumulator 17 is connected in the pipe 16. The motor 14 is a conventional variable speed AC motor, and the pump 15 may be a conventional centrifugal pump. A conventional one-way check valve is usually provided in the pipe 16 or between the pump and the pipe. Electrical power to drive the motor 14 is supplied through a drop cable 18 connected between the motor 14 and a variable frequency drive or power circuit 19.
The drive circuit 19 may comprise a conventional DC link arrangement as illustrated in FIG. 3. A standard 60-cycle AC supply 21 is connected by conductors 22 to a rectifier circuit 23 which produces a DC voltage on lines 24. An inverter 26 is connected to the lines 24 and converts the DC voltage to a three-phase variable frequency AC supply voltage on polyphase lines 27, and the motor 21 is connected to the lines 27. In the embodiment of the invention shown in FIG. 1, the three lines 27 form the drop cable 18.
The frequency of the supply voltage on the lines 27 is controlled by an electrical speed command signal on a line 31, shown in FIGS. 1 to 3, formed by a control circuit 32 (FIGS. 1 and 2). With reference first to FIG. 1, the control circuit 32 includes a pressure sensor 33 which supplies pressure signal representing the liquid pressure in the pipe 16. The sensor 33 may be mounted in the pipe 16 downstream from the tank 17 as shown by the solid lines or upstream from the tank 17 as shown by the dashed lines, for example. The pressure signal appears on a line 34 that is connected to a summation point or circuit 36 which also receives a set point signal on a line 37. A set point circuit 38 generates the set point signal in accordance with the setting of a dial 39, the setting being at a desired liquid pressure in the pipe 16. The summation circuit combines the signals on the lines 34 and 37 and produces an error signal on a line 41 which represents the deviation of the actual pressure in the pipe from the desired or preset pressure.
The error signal is connected by the line 41 to a conventional p+i (proportional plus integral) controller 42 of a type which is known to those skilled in this art. The controller 42 generates a speed command signal derived from the error signal, and the speed command signal is connected by the line 31 to control the drive 19. Thus, the liquid pressure in the pipe 16 is a function of the speed of the motor-pump unit 13, the speed of the unit 13 is a function of the frequency of the drive 19, which, in turn, is a function of the speed command signal and the error signal.
The foregoing describes the normal operation of the system when the pipe 16 is opened to allow flow out of the pipe 16. Such flow causes the pressure to start to drop, thereby generating error and speed command signals which cause the unit 13 to pump liquid. The quantity of liquid pumped is essentially equal to the quantity being dispensed from the pipe 16, thereby maintaining the liquid pressure essentially constant at the selected level.
If only the portion of the control circuit 32 described thus far were provided, a problem may be encountered when the pipe 16 is closed and the flow of liquid stops. The motor-pump unit 13 is preferably operated only when there is flow out of the pipe 16 which should be replaced. A feedback control loop as described above is not able to recognize a condition where the flow has stopped because it senses pressure only and does not include a flow sensor for sensing liquid flow. Consequently, the system will attempt to continue normal operation and maintain pressure regulation.
To turn of the unit 13 when flow out of the pipe 16 has stopped, without utilizing a flow sensor (which is an expensive item that would also have to be connected in the pipe 16), the control circuit is constructed in accordance with this invention to sense when the flow has stopped, utilizing only the pressure sensor 33. Broadly stated, this is accomplished by periodically reducing the speed of the motor. If there is continued flow out of the pipe 16, the pressure at the sensor 33 immediately drops when the motor slows down; this pressure drop is sensed and is utilized to return the motor to a higher speed necessary to maintain a constant pressure. On the other hand, if there is no flow out of the pipe 16, the pressure does not drop when the motor slows down. This condition is recognized and utilized to turn off the power to the motor; the motor remains off until the pressure starts to drop due to subsequent flow out of the pipe 16.
More specifically, a switch 51 is connected between the control 42 and the line 31. While the drawing shows a mechanical two-position switch 51, an electronic switching circuit may be used instead. The switch 51 includes a movable contact 52, a stationary normal contact 53 connected to the control 42, and a stationary dip contact 54 connected to a programmed speed dip circuit 56. When in the solid and dashed line positions, the switch 51 connects the control 42 or the speed dip circuit 56, respectively, to the drive 19. The circuit 56 is programmed to ramp down the speed of the motor 14 to zero.
The position of the switch 51 is controlled by a timer 57. The contact 52 has the normal position shown by the solid line in FIG. 1, but periodically the contact 52 is moved by the timer 57 to the test position shown by the dashed line. The timer 57 is connected by a line 58 to receive a reset signal from a pressure monitoring circuit 59 which receives the pressure signal on the line 34. The circuit 59 is responsive to a change (ΔP) in the liquid pressure, and it also forms the time derivative (dp/dt). The presence of either a pressure change (ΔP) or the derivative (dp/dt) produces a reset signal on the line 58, which resets the timer 57 and moves the contact 52 back to the normal solid line position.
To summarize the operation of the system shown in FIG. 1, assume that the unit 13 is initially turned off, that the pressure in the pipe 34 is at the desired level, and that the switch 51 is in the normal position. When the pipe 16 is opened to allow flow of the liquid out of the pipe, the pressure immediately starts to drop, resulting in an error signal on the line 41 and a speed command signal on the line 31. The control 42 and the drive 19 (which include conventional ramp circuits) then power the unit 13 at a speed which returns the pipe 34 pressure to the value set in the circuit 38. The feedback circuit operates to move the error signal toward zero; in other words, the speed of the unit 13 is such that it pumps the liquid at the rate at which it flows out of the pipe 34, thereby maintaining the pipe pressure at a substantially constant value.
At the end of the period of the timer 57, the timer moves the switch contact 52 to the speed dip circuit 56 which causes the speed of the unit 13 to slow down. If the liquid is still flowing out of the pipe 34, the slowdown of the unit 13 causes the monitoring circuit 59 to produce both a pressure change (ΔP) signal and a derivative (dp/dt) signal, either one of which causes a reset signal on the line 58 to immediately reset the timer 57 and to return the switch 51 to the normal position. The speed of the unit 13 immediately increases to return the pressure to the preset value. The length of time for the switch to move from the normal to the test position and return to the normal position is very short so that the drop in pressure is nearly imperceptible. At the end of each timer 57 period (which may, for example, be about 10 seconds), the foregoing test procedure is repeated so long as flow continues out of the pipe 16.
On the other hand, if the pipe 16 is closed to stop the flow out of the pipe, the unit 13 will slow down, but may not stop (a centrifugal pump or a jet pump may enable the unit 13 to continue without flow out of the pipe 34). When the timer 57 moves the switch 51 to the test position, the monitoring circuit 59 will not generate a reset signal because the pipe pressure does not drop. Consequently, the timer 57 will not be reset, and the switch 51 will remain in the reset position. As previously mentioned, the circuit 56 includes a ramp circuit for ramping the drive 19 down to zero frequency and the unit 13 down to zero speed. The system will remain in this condition until the pipe 16 is subsequently opened to allow liquid flow, causing the generation of a reset signal, resetting of the timer 57, and movement of the switch 51 to the normal position. Operation then continues as described above.
The circuit shown in FIG. 2 is a more detailed version of part of the circuit shown in FIG. 1, and the same reference numerals are used for the corresponding parts. The speed dip circuit 56 is formed by a ramp generator which will ramp the motor speed to zero if the timer 57 is not reset, A line 65 connects the output of the control 42 to the generator 56 so that the generator 56 is initialized with the control 42 signal. This prevents a step change in the motor speed when the switch 51 moves to the test position. Similarly, a line 66 connects the output of the generator 56 to the control 42 in order to initialize it and prevent a step change when the switch 51 moves to the normal position.
The pressure monitoring circuit 59 includes a differentiator circuit 67 connected by a line 68 to receive the liquid pressure signal from the sensor 33. The differential of the pressure signal is fed to an absolute value circuit 69, and the absolute value is fed to a comparator circuit 71 where it is compared with a limit signal on a second input 72. If the absolute value is greater than the limit signal, the comparator 71 passes a signal through an OR circuit 72 to reset the timer 57.
Similarly, the error signal on the line 41 is connected by a line 73 to an absolute value circuit 74, and the absolute value error signal is fed to one input of a comparator circuit 74. A limit signal is fed on a second input 76 to the comparator 74, and if the error signal exceeds the limit value, the comparator 74 sends a signal through the OR circuit 72 to reset the timer 57.
It will be apparent that either an excessive change of pressure signal or an excessive rate of change of pressure signal will reset the timer. The former is more likely to occur if the accumulator tank 17 is relatively large, whereas the latter is more likely to occur if the tank 17 is relatively small. A water tank for a typical domestic house may be about three gallons when using a system in accordance with this invention, whereas tanks in common use with most domestic water supplies are about 15-30 gallons. The size of tanks for other uses will depend upon the quantity of liquid normally being pumped.
FIG. 4 illustrates an alternative embodiment of the invention, including a motor-pump unit 81 suspended in a well 82 by a pipe 83. The pipe 83 conveys pumped liquid 84 (such as water) to a pressure/storage tank 86 and to a pipe 87 of a domestic plumbing system. A pressure sensor 88 is connected in the pipe 83, and a control module 89 controls the power to an electric motor of the unit 81.
The control module 89 includes the AC to DC rectifier 23 shown in FIG. 3 and the control circuit shown in FIGS. 1 and 2. The system of FIG. 4 includes a drop cable 90 which connects the control module 89 with the unit 81. In this system, the cable 90 is formed by the two wires 24 of the DC link, and the DC to AC inverter 26 is contained in a casing 91 that is part of the unit 81. The variable frequency output of the inverter 26 is connected to the adjacent motor 92 of the unit 81.
The arrangement shown in FIG. 4 has a number of advantages. The drop cable 90 has only two wires instead of three as in the system of FIGS. 1 to 3; the inverter 26 is closely adjacent the motor and it may be cooled relatively easily by the well water; and the rectifier 23 is readily accessible and is adjacent the pressure sensor at the ground surface.
The pressure sensor, the DC link, and the control circuit of FIGS. 1 to 3 may be mounted on the pipe 16, as described in the pending patent application of Jimmy Cochimin titled Liquid Pumping System, filed simultaneously herewith. In the system of FIG. 4, the pressure sensor and the control module 89 may be mounted on the pipe 83 as described in the above Cochimin pending patent application. The disclosure of the above pending patent application is incorporated herein by reference.
While the drawings and the description disclose a control including electronic components, the control could instead be implemented with a programmed microcontroller, whereby the circuits are replaced by calculations and the contacts replaced by branches of program logic.
A system constructed in accordance with this invention has numerous advantages as compared with conventional systems. It may easily be connected in a supply system because it includes a pressure sensor but does not require a flow sensor. The size of the pressure/storage tank (also referred to as an accumulator) is substantially less than that of a conventional supply system, thereby requiring less expense and space. Still further, the system provides liquid at a substantially constant pressure while the motor-pump unit is operating, thereby avoiding the pressure swings found in conventional domestic water supply systems. While the motor-pump unit is turned off, the system pressure will be maintained by a conventional check valve 93 (FIG. 4) which is normally provided between the pump 94 and the pipe 83. In the arrangement where the inverter is included in the motor and the rectifier is located above ground, only a two-wire drop cable carrying a variable DC voltage is needed. The wires carrying the pressure signal is connected to the rectifier which may be located close to the pressure sensor. | This disclosure relates to a liquid supply system including a motor-pump unit designed for installation in a liquid supply such as a well or storage tank. The unit supplies the liquid to a supply pipe, and a pressure sensor connected to the pipe is operable to provide a control signal representative of the liquid pressure in the pipe. The motor is a variable-speed AC motor. A control for the motor is responsive to the control signal and actuates a power circuit to drive the motor at a speed adjusted to maintain the liquid pressure at a substantially constant value. The control circuit further includes means for turning off the power to the motor in the absence of flow through pipe, which does not require a flow sensor. The power circuit comprises a DC link including a rectifier and an inverter. The rectifier is located adjacent the pressure sensor; the inverter may be located adjacent the rectifier and the pressure sensor or in the casing of the motor-pump unit. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Cross reference is made to:
[0002] U.S. patent application Ser. No. ______, filed Jan. ______, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-3);
[0003] U.S. patent application Ser. No. ______, filed Jan. ______, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-4); and
[0004] U.S. patent application Ser. No. ______, filed Jan. ______, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-5), all of which are incorporated herein by this reference in their entirety.
FIELD OF THE INVENTION
[0005] The invention relates generally to set-top boxes and more particularly to one or more profiles associated with a set-top box. Additional aspects of the invention relate to the interoperability of STB's, one or more profiles and one or more applications associated with the open cable application platform.
BACKGROUND OF THE INVENTION
[0006] Multiple Service Operators (MSOs), e.g., cable companies, are working to transform their value proposition from one dominated by basic subscriptions and equipment leases to a customer service driven value model. One of the reasons for this is the recent ruling by the Federal Communications Commission (FCC), which has been upheld in court, that MSOs adopt the Open Cable Application Platform (OCAP) and that Set-Top Boxes (STBs) be open to other uses. With larger pipes, more powerful STBs, and improved customer service applications residing in those STBs, the MSO can begin to dominate the other Local inter-Exchange Carriers (LECs). This enhanced customer service value equation is viewed to be one key to continued MSO growth, increased revenue and increased margins. OCAP is a new paradigm that will allow MSOs to create, or have made, and deploy, a whole suite of new interactive communications services that can drive new revenue streams with higher margins for the MSOs. The OCAP middleware, written in the Java® language, will facilitate “write once, use anywhere” application software to provide new features and services created by third party developers.
[0007] The OpenCable™ Platform specification can be found at http://www.opencable.com/ocap/, “OpenCable Application Platform Specification (OCAP) 1.1,” which is incorporated herein by reference in its entirety.
[0008] OCAP is an operating system layer designed for consumer electronics, such as STBs, that connect to a cable television system. Generally, the cable company controls what OCAP programs can be run on the STB. OCAP programs can be used for interactive services such as eCommerce, online banking, program guides and digital video recording. Cable companies have required OCAP as part of the CableCard 2.0 specification, and they indicate that two way communications by third party devices on their networks will require them to support OCAP.
[0009] More specifically, OCAP is a Java® language-based software/middleware portion of the OpenCable initiative. OCAP is based on the Globally Executable MHP (GEM)-standard, as defined by CableLabs. Because OCAP is based on GEM, OCAP shares many similarities with the Multimedia Home Platform (MHP) standard defined by the Digital Video Broadcasting (DVB)-project. The MHP was developed by the DVB Project as the world's first open standard for interactive television. It is a Java® language-based environment which defines a generic interface between interactive digital applications and the terminals on which those applications execute. MHP was designed to run on DVB platforms but there was a demand to extend the interoperability it offers to other digital television platforms. This demand gave rise to GEM, or Globally Executable MHP, a framework which allows other organizations to define specifications based on MHP.
[0010] One such specification is OCAP which has been adopted by the US cable industry. In OCAP the various DVB technologies and specifications that are not used in the US cable environment are removed and replaced by their functional equivalents, as specified in GEM. On the terrestrial broadcast side, CableLabs and the Advanced Television Systems Committee (ATSC) have worked together to define a common GEM-based specification, Advanced Communications Application Platform (ACAP), which will ensure maximum compatibility between cable and over-the-air broadcast receivers.
[0011] Packet Cable 2.0 is a specification based on the wireless Third Generation Partnership Program (3GPP) Internet protocol Multimedia Subsystem (IMS), which uses Session Initiated Protocol (SIP) for session control. By using SIP, MSOs can create the foundation of a service delivery platform on top of their existing DOCSIS (Data Over Cable Service Interface Specification) or cable modem service. Two of the SIP features that are particularly important to this invention are extensibility and interoperability. These SIP features are important because new messages and attributes can be easily defined and communications between previously incompatible endpoints are facilitated.
[0012] Another development that sets the stage for the disclosed inventions is the processing power, multimedia codecs and storage capabilities of the STBs. Many of the more advanced STBs have Digital Video Recorders (DVRs) based on hard disk drives or flash memory that provide many gigabytes of available storage. They also have advanced audio/video codecs designed to handle the requirements of High Definition Television (HDTV). Processors such as the Broadcom BCM7118 announced in January 2007, provide over 1000 Dhrystone mega-instructions per second (DMIPS) worth of processing power to support OCAP, new customer applications, and DOCSIS 2.0 and DSG advanced mode. The Broadcom chip, and other general purpose and application-specific integrated circuit (ASIC) processors used for STBs, provide powerful security capabilities such as the emerging Polycipher Downloadable Conditional Access Security (DCAS) system. DCAS eliminates the need for a CableCard and supports multiple conditional access systems and retail products.
SUMMARY OF THE INVENTION
[0013] These technologies provide the platform for a greatly enhanced, multimedia, customer communication experience. Specifically, one exemplary aspect of this invention is advanced multimedia communications via OCAP using customer specific profiles resident in the STB. Telephony application servers have already been proposed by CableLabs and others. Phone and STB association can be done in the MSO network. Similarly, personalized information for the display of financial data, home security information and the like, is also known.
[0014] However, an exemplary aspect of this invention utilizes storage of personalized information and communication preferences in the STB in a structured format or via cookies. The combination of feature rich telephony applications with the personalized data stored in STBs facilitates feature rich communications sessions. Providing advanced multimedia communications applications using personalized data resident in STBs could allow the MSOs to provide, for example, many previously unavailable services, and therefore provide considerable new business potential.
[0015] The types of personal information that can be stored in STBs may include, but are not limited to, communication preferences, payment preferences, vendor preferences, priority preferences, personal information, etc. Examples of communications preferences could include when to be reached or not reached, numbers to reach, calendar synchronization, etc., and in general any information related to communications. Examples of payment preferences could include credit card information, direct deposit/debit information, what financial instrument was used for the most recent transaction with a specific company, and in general any information related to transactions. Examples of vendor preferences could include favorite delivery pizza, most commonly ordered items, etc. Examples of priority preferences could include conditions like don't interrupt me watching the Chicago Bears beat the Green Bay Packers unless it is my boss calling, and in general any preference that can be used to assist with priority determinations. Examples of personal information could include clothing or shoe size, favorite colors, name, address, etc., and in general any information about an individual(s). Other such personal information categories and variations stored in STBs as can be imagined by one schooled in this art are also within the scope of this invention disclosure.
[0016] Screen menus, pushed URLs, and adaptations specific to various devices connected to STBs (such as different size screens, different capability devices, etc.) can be rendered as part of this process of enhanced communications. Similarly contextual favorites or preferences can be provided depending on what content is being displayed or interacted with.
[0017] When one combines the integration of a profile, such as, for example, personal information in STBs, with applications resident in a variety of places on the MSO's network, these new value added services are enabled.
[0018] A few simple examples of what is possible could include, but are not limited to, enhanced web enabled service transactions, mobile requests for goods or services using the profiles and communication capabilities of the STB/MSO network, display of or sharing of information among two or more individuals, etc.
[0019] For example, the user can initiate a service transaction on the STB itself. The exemplary menu based request will use the stored service information entry to key a web service request. If the request should trigger a human response (like communication with a retention agent when service cancellation is requested), then the STB information can key to the customer phone for an outbound call to confirm the cancellation request and allow the agent to describe a retention offer.
[0020] Another example could be a user delayed at work wanting to order a pizza to be ready shortly after their arrival at their home. The user can access personal information in their remote STB about their preferred vendor, most recent order and previous method of payment. They can place a new pizza order based on this stored information rather than having to key or speak all this information while driving. The user benefits from an enhanced user experience, the accuracy of the order is improved, and they can have the food arrive closely timed with their own arrival at home.
[0021] Another example is when a user has relocated to a new city or state; they may not have had the time to develop favorite vendors for pizza or other goods and services. In such a case, the MSO can push a list of preferred partners to the new user that the new user can edit or modify based on their own personal experiences and preferences.
[0022] The exemplary embodiments discussed herein just hint at the power of the proposed enhancement to this new communications paradigm. There are many other potential examples and applications to serve them that are possible.
[0023] For example, it is generally recognized that an intelligent agent is a software agent that assists users and will act on their behalf, in performing non-repetitive computer-related tasks. An agent in this sense of the word is like an insurance agent or a travel agent. While the working of software agents used for operator assistance or data mining (sometimes referred to as bots) is often based on fixed pre-programmed rules, “intelligent” in this context is often taken to imply the ability to adapt and learn. The term “personal” indicates that a particular intelligent agent is acting on behalf of an individual or a small collective group of users such as a household, business entity, etc.
[0024] OCAP provides another venue for an intelligent personal agent but offers several advantages compared with previous attempts at this type of application. One is the fact that STBs are already equipped to handle two-way, full-motion, High Definition (HD) video, as well as any other communication media. Another advantage is the integration of the personal profile information with the Intelligent Personal Agent application. Another is the improved security discussed herein. The extensibility and the interoperability that the Session Initiation Protocol (SIP) adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged.
[0025] Another exemplary aspect of the invention is the use of personalized information and personal preferences contained in a STB in combination with an intelligent personal agent application and improved security to provide, for example, a greatly enhanced user agent experience.
[0026] The fact that sensitive information about the user can be stored within their own STB reduces security concerns associated with having too much web presence. The disclosure or query of the personal information can be established on a trust basis which also helps with security and privacy. The push of security information such as DCAS makes the environment significantly safer. One could also envision if there are multiple users within one household, that they can each have a profile that is login protected for personal privacy. Parents would be able to set certain conditions/limits for children using the intelligent personal agent application that would also add to the safety and age appropriate use of the application.
[0027] The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to current intelligent personal agents. It could provide an opportunity for video messages to be personalized for the party which is initiating the contact.
[0028] The personal information stored in the STB can convey many exemplary benefits such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, as well as multimedia messaging, etc. The integration of the personal information with the intelligent personal agent also enhances the user experience.
[0029] There are several examples of what this idea can provide the user that current intelligent agents are not able to do. One is the ability to greet calling parties with a full motion video greeting unique to that calling party. Another is the ability to handle more complicated transactions. For example, the user wants to buy a particular item at a particular price from one of several preferred vendors. Offers from preferred business partners can be pushed to the MSO's users and the content can be filtered, compared with conditions set by the user for a purchase, and the intelligent personal agent can either complete the transaction or call the user on a mobile device to seek approval and then transact business. While there are shopping agents, mobility applications and contactless payment devices, this intelligent agent can provide a user experience unequaled in the current art. Another possible variation is for the intelligent personal agent to coordinate multiple parties within a household. Let's say an invitation arrives inviting a family over to dinner at the calling party's house. The intelligent agents can interact with personal information and scheduler software for all of the members of the family to make certain that the invite has considered each members previous commitments prior to replying and either accepting or modifying the proposed dinner invitation. There are numerous other variations that are possible with this intelligent personal agent not possible within the existing art.
[0030] Social network services focus on the building and verifying of online social networks for communities of people who share interests and activities, or who are interested in exploring the interests and activities of others, and that necessitates the use of software.
[0031] Most social network services are primarily web based and provide a collection of various ways for users to interact, such as chat, messaging, email, video, voice chat, file sharing, blogging, discussion groups, and so on.
[0032] The main types of social networking services are those that contain directories of some categories (such as former classmates), means to connect with friends (usually with self-description pages), and recommender systems linked to trust. Popular methods now combine many of these, with MySpace™, Bebo™ and Facebook™ services being the most widely used.
[0033] OCAP combined with personal profile information provides another venue for a social network, but offers several advantages compared with previous attempts at this type of application. One is the fact that, as discussed, STBs are equipped to handle two-way, full-motion, High Definition (HD) video. Another is the improved security discussed above. The extensibility and the interoperability that SIP adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged. One exemplary embodiment of the social network proposed here can be one-to-one, one-to-many and many-to-one, and can cover both personal and professional interest areas.
[0034] Another exemplary aspect of this invention is the use of personalized information and personal preferences contained in a STB combined with two-way, full-motion, HD video and improved security to provide a greatly enhanced social networking experience.
[0035] The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to the current social networking offerings. It would provide an experience that is much more like a face-to-face interaction.
[0036] The personal information stored in the STB can convey all of the benefits listed above such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, etc. The integration of the personal information combined with the social networking application(s) also enhances the user experience.
[0037] In addition to the normal uses of a social networking application such as on-line dating, discussion groups, virtual communities, and the like, one can imagine extensions to the use of this application. One such extension would be the addition of personal reviews of restaurants, movies, books, music, and the like. Other users of the social network could determine over time which reviewers tend to rate goods and services consistently with their interests and/or from a perspective that they enjoy their reviews, and could preview the ratings provided about items of interest by those reviewers. One could also see reviews when previewing related media. The reviewers and the users that tend to agree or become popular could go on to form their own social network based on their experience with each other's recommendations or interactions. With the extensibility of Packet Cable 2.0, a user could also provide a review of a movie that they had just viewed in a theater via their cell phone while their thoughts are fresh.
[0038] Many small businesses start out as part-time home businesses. In addition, some people run a small business focusing on rental properties, or the like, in parallel with their normal employment. Some fairly sizable businesses are run at locations served by MSO DOCSIS services. OCAP provides an opportunity to integrate business profile information into STBs similar to how personal information is integrated in a STB, as discussed in above. Further, business application software, such as the Quicken® Home and Business program or the Quicken® Rental Property Manager program can be advantageously integrated together with business information profiles in the STB.
[0039] There are many other instances where OCAP can provide an enhanced user experience to business users. Via OCAP, and with a business profile, actual inventory levels can be compared with desired levels stored as business information in the STB. Since preferred vendor and preferred payment information can also be stored, when inventory runs below a certain level, it can be automatically ordered, or alternatively, OCAP can provide a pop-up or call a specified phone number such as a mobile phone to confirm that the inventory reorder should be processed.
[0040] Another example would be management of a rental vacation property. Not only could the landlord view bookings and the like, but the ability to extend a rental stay could be offered to the guest via the TV/STB when such an opening is available. Further, an offer to return at a future date could also be made via OCAP. In this way, the renter feels that they are getting increased attention without significant intrusion, and the landlord is more likely to be able to keep the rental property at maximum capacity.
[0041] While the internet provides some of these types of features, OCAP allows for, as an example, a richer feature set, improved convenience and the ability to leverage previously incompatible devices in a seamless way. Specifically, the ability to reorder inventory when the small business owner is mobile, and the ability to provide all of the information regarding the transaction such as vendor, inventory type and quantity, preferred payment options, and the like, without the small business owner having to key in such information, is useful. Similarly, renting vacation properties is typically done via the internet. However, not everyone takes a PC or web-enabled device everywhere with them. Offering the ability to extend a stay, rebook a future vacation, or offer incentives to good repeat guests can all be done via OCAP and displayed on a TV or forwarded as an audio message to the rental property phone.
[0042] The use of business information and business preferences contained in a STB integrated with other PC or STB-based business software can provide full compatibility with previously incompatible endpoints and improved security to provide a greatly enhanced business experience.
[0043] The fact that sensitive information about business(es) can be stored within their own STBs improves security concerns associated with web-based attacks. The disclosure or query of the business information can be established on a trust basis, which also helps with security and privacy. The push of security information, such as DCAS, also makes the environment significantly safer. One could also envision, if there are multiple users within one entity, that they can each have a profile that is login protected for privacy. In addition, one or more members of the entity can also have a business profile in the STB.
[0044] The two-way, full-motion, HD video, without many of the quality issues associated with the Internet, is also a significant enhancement to businesses. It provides, for example, an opportunity for video messages to be personalized to the guest or customer when the business owner is unavailable.
[0045] The business information stored in the STB can also convey the benefits of personal information listed above, such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, inventory levels, business events/calendar, as well as multimedia messaging, etc. The integration of the business information combined with existing business software enhances the business owners' ability to conduct their businesses.
[0046] There are several examples of what this idea can provide to the business user that current PC based software does not allow. One is the ability to greet guests and customers with a full motion video greeting unique to each party. Another is the ability to handle more complicated transactions. For example, a vacation rental guest decides that they really like the property that they rented, but would like to consider other such properties for a future vacation prior to the end of their current vacation. Offers from the landlord can be extended to preferred guests while on their current vacation for reduced rate stays at this or other properties, to retain the guest's business. All of this can be displayed to the TV at the property, or if the TV is not used, sent via an audio message to the phone in the rental. There are numerous other variations that are possible with this business application and profile that are not possible within the existing art.
[0047] Aspects of the invention thus relate to one or more profiles on a STB.
[0048] Aspects of the invention further relate to the use of personalized information and personal preferences associated with a STB combined with an intelligent personal agent application and improved security to provide an enhanced user experience.
[0049] Aspects of the invention also relate to use of a personalized profile of communications preferences and personal information resident in STBs combined with communications applications also resident in STB's to enable enhanced communications and customer service in an OCAP/IMS network(s).
[0050] Aspects further relate to having business information and preferences stored in STBs, an OCAP business application combined with existing business software and enhanced security within an OCAP/IMS network(s).
[0051] Aspects also relate to use of a personalized profile of communications preferences and personal information resident in a STB combined with two-way, full-motion, high definition video and enhanced security to implement a social networking application within an OCAP/IMS network(s).
[0052] Aspects also relate to utilizing a master profile to regulate creation and use of subordinate profile(s).
[0053] Aspects also relate to integration and cooperation between a profile associated with a STB and one or more applications associated with other electronic devices.
[0054] Aspects of the invention can also be used to support enhanced e-commerce in association with a STB.
[0055] Aspects still further relate to business management in conjunction with one or more business profiles on a STB.
[0056] Aspects also relate to setup and use of an automated agent performing certain tasks in association with a profile associated with a STB.
[0057] Additional aspects relate to a set-top box with an operating system layer supporting cable network interconnectability and providing an application platform on which one or more customer service applications can be run.
[0058] Aspects still further relate to use of social networking applications and integration with a profile associated with a STB.
[0059] These and other needs are addressed by the various embodiments and configurations of the present invention.
[0060] The present invention can provide a number of advantages depending on the particular configuration.
[0061] These and other advantages will be apparent from the disclosure of the invention(s) contained herein.
[0062] The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
[0063] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.
[0064] The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic even if performance of the process or operation uses human input, whether material or immaterial, received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material”.
[0065] The term “computer-readable medium” as used herein refers to any tangible storage and/or transmission medium that participate in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read. A digital file attachment to e-mail or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the invention is considered to include a tangible storage medium or distribution medium and prior art-recognized equivalents and successor media, in which the software implementations of the present invention are stored.
[0066] The terms “determine”, “calculate” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.
[0067] The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the invention is described in terms of exemplary embodiments, it should be appreciated that individual aspects of the invention can be separately claimed.
[0068] The preceding is a simplified summary of the invention to provide an understanding of some aspects of the invention. This summary is neither an extensive nor exhaustive overview of the invention and its various embodiments. It is intended neither to identify key or critical elements of the invention nor to delineate the scope of the invention but to present selected concepts of the invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 illustrates an exemplary content system according to this invention;
[0070] FIG. 2 illustrates an exemplary set-top box according to this invention;
[0071] FIG. 3 illustrates an exemplary profile according to this invention;
[0072] FIG. 4 is a flowchart outlining an exemplary method for creating or editing a profile according to this invention;
[0073] FIG. 5 is a flowchart outlining an exemplary method for performing a service transaction according to this invention;
[0074] FIG. 6 is a flowchart illustrating the exemplary interaction between a set-top box and a service provider according to this invention;
[0075] FIG. 7 illustrates an exemplary flowchart for intelligent agent performance according to this invention;
[0076] FIG. 8 is a flowchart illustrating an exemplary method for utilization of a business profile according to this invention;
[0077] FIG. 9 is a flowchart outlining an exemplary method for social network interaction according to this invention;
[0078] FIG. 10 is a flowchart outlining an exemplary method for initiating a transaction in greater detail according to this invention;
[0079] FIG. 11 is a flowchart outlining an exemplary method for storing transaction information in greater detail according to this invention; and
[0080] FIG. 12 is a flowchart outlining an exemplary method for social network interaction in greater detail according to this invention.
DETAILED DESCRIPTION
[0081] FIG. 1 illustrates an exemplary content system 100 . The system 100 comprises one or more trusted entities 200 , one or more content/service providers 300 , such as a cable company, and a set-top box 500 , all interconnected by one or more links 5 and networks 10 . The set-top box 500 is connected to one or more of a stereo 700 , PC 800 , TV 900 , or in general any electronic device as represented by box 600 . Associated with the set-top box 500 are one or more profiles 400 , as will be discussed in detail hereinafter.
[0082] In general, the set-top box 500 is capable of receiving content, such as video content, as well as providing services such as access to the internet, telephony service, and the like. As will be discussed hereinafter, the set-top box is also capable of providing services such that, for example, the user located at one of the attached devices utilizes the set-top box 500 to assist with the ordering, consumption and/or management of the service.
[0083] Typically, the content/service provider 300 provides content, such a video content, to a user via the set-top box 500 . An exemplary embodiment of the present invention expands on this concept and in conjunction with profile 400 provides enhanced content capabilities through the set-top box 500 .
[0084] Furthermore, and in accordance with an optional exemplary embodiment, trusted relationships can be established between the content/service provider 300 and one or more trusted entities 200 . For example, the content/service provider 300 , such as a cable company, can negotiate trusted relationships with various service providing entities. Upon the completion of various checks and assurances from the service providing entities, the various entities could be listed as a trusted entity 200 , at which point service requests made via set-top box 500 , in conjunction with profile 400 , would be handled in a different manner.
[0085] The association of the profile 400 with the set-top box 500 allows, for example, a richer communications environment to be provided to a user. For example, a customer at their home calls into a customer service number. Instead of the call being rerouted from center to center based on information the customer inputs via the phone, the call can use a common customer routing center. The routing center, which could be one of the trusted entities 200 , can use the phone number to look-up a key set-top box entry for the customer, and the center can then electronically retrieving the stored service information entry via the set-top box 500 , from the profile 400 . The information retrieved from the profile 400 can be combined with the caller's requested service, routed to the appropriate agent with the information retrieved from the customer STB (relieving the need to interrogate other databases or the user and making for more efficient contact centers), and additional information for the customer can be displayed on, for example, the TV 900 or PC 800 associated with the set-top box 500 .
[0086] In another example, the customer can initiate a service transaction on the set-top box itself. For example, a menu based request can use stored service information in the profile 400 to key a web service request. If the question triggers a human response, like that from a retention agent when service cancellation is requested, the set-top box information can key to the customer phone for an outbound call to confirm the cancellation request and allow for a retention offer to be made.
[0087] Therefore, in accordance with one exemplary embodiment, the profile 400 can be used, for example, to assist with contacts to a contact center and can be utilized in conjunction with the set-top box to provide a service to, for example, other retailers, service outfits, and trusted or other entities. The set-top box can also store customer service records specific to, for example, an individual or a business. The same method used to assist with a customer service contact as discussed above could similarly be used to access records or other information stored in the profile 400 to assist with business services, business management, online banking, or the like.
[0088] For example, the same mechanisms can be used to push structured information and menu information for the requested transaction, inquiry, or service request, thereby providing a richer customer service experience. This richer experience combined with the ease of retrieval of customer service information, personal information and/or business information from the profile 400 provides, for example, a significantly richer customer contact capability than that which can be offered by traditional centers. This in turn gives an opportunity for new large business service opportunities for the contact/service provider 300 .
[0089] In accordance with an exemplary embodiment, the profile 400 used in conjunction with one or more applications on the set-top box 500 provides a richer experience for a user of the set-top box for interacting with one or more content/service providers, trusted entities, other entities, or in general any entity that may be able to provide a richer customer experience based on the information available to them via the profile 400 .
[0090] FIG. 2 illustrates in greater detail an exemplary set-top box 500 . The exemplary set top box includes one or more of a DVR 510 , codec 515 , hard drive 520 , one or more customer service applications 525 , a binding hardware/software module 530 , a menu module 535 , a business application integration module 540 , a social network applications module 545 , a processor 550 , a memory 555 , an I/O interface 560 , a SIP functionality/integration module 565 , a security module 570 , one or more communications applications 575 and an intelligent agent module 580 .
[0091] The DVR 510 can be used to store video information, as is conventionally known, and can also be used as a storage device for one or more applications on the set-top box. For example, the DVR 510 can used as back up for non-active applications, while active applications can be run on, for example, the hard drive 520 in conjunction with one or more of the processor 550 , memory 555 and I/O interface 560 .
[0092] The set-top box can also include one or more codecs 515 that provide, for example, one or more of coding and decoding of video information, audio information, high-definition video information, multimedia information, or in general any audio or video format received by or sent from the set-top box 500 .
[0093] The set-top box 500 also includes one or more customer service applications 525 . These customer service applications can cooperate with the profile 400 to provide various functionalities to a user at one or more of a TV 900 , PC 800 , stereo 700 , or in general any electric device 600 connected to the set-top box 500 . As discussed above, these customer service applications can include, but are not limited to, ordering, online banking, call center assistance applications, profile management applications, or in general any application that is capable of operating on or in conjunction with the set-top box 500 . As will be appreciated, the application need not run exclusively on the set-top box 500 , but could operate in conjunction with one or more applications, on, for example, a connected electronic device such as PC 800 .
[0094] The hardware/software binding module 530 allows the set-top box 500 to be associated with one or more other electronic devices, such as a telephone, soft phone, or in general any device that is capable of being bound to the set-top box 500 . For example, if a user activates a customer service application on the set-top box 500 to cancel the particular service with a trusted entity 200 , upon the intelligent agent module (discussed hereinafter) determining that a cancellation service request has been initiated, the intelligent agent module can request the hardware/software binding module to initiate a call so that the user can communicate directly with the trusted entity customer service agent regarding the cancellation request. This binding can be done, for example, with the cooperation of the SIP functionality/integration module 565 , in that SIP provides a convenient mechanism to established, tear down, or redirect communications. More specifically, stored within the profile can be information specifying phone information associated with the user of the set-top box. SIP protocols can be initiated from the STB to specify that the phone associated with the user is to place a call to a specific customer service agent. A message indicating that a phone call has been initiated can then be displayed on one or more of the phone and a device associated with the STB 500 .
[0095] The menu module 535 provides an interface, such as a graphical user interface, which can be displayed on one or more of the TV 900 , PC 800 , or in general any display device that allows manipulation of, for example, one or more of the features of the set-top box 500 and one or more profiles. For example, a user can utilize the menu module 535 to edit one or more profiles 400 stored on the set top box. Additionally the menu module 535 can used in conjunction with various customer service applications 525 residing on the set top box to provide necessary menus to the user associated with the particular customer service application that was requested. For example, in an on-line banking environment, where their customer service application provides to the user the ability to manage their bank accounts, the customer service application can serve various menus in conjunction with the menu module 535 that allow the various actions associated with the customer service application to be performed. Menu module 535 can also cooperate with one or more of the content/service provider 300 , trusted entities 200 , or other entities on the network 10 , to provide menus to a user of the set-top box 500 in conjunction with one or more of the services, products, or features provided by that particular entity.
[0096] For example, if the set-top box 500 is in communication with a real estate agent connected to network 10 , the real estate agent could push a series of menus to the menu module 535 that allow the user of the set-top box 500 to access various listings of that agent. With these menus, the user could set up, for example, virtual viewings of the listing in high-definition video formation. The SIP functionality 565 could also be used to spawn a call that is bound to the real estate viewing application in conjunction with the hardware/software binding module 530 . Personal preferences of the user could also be layered on top of the menus pushed to the STB to account for their own personal preferences, such as skin-type display characteristics.
[0097] The business application integration module 540 allows one or more business applications stored on, for example, PC 800 , to be utilized in conjunction with the set-top box 500 and profile 400 . In addition to the stand-alone business application(s) stored on the set-top box, the business application integration module 540 allows for integration and sharing of information stored in, for example, the profile 400 with one or more business applications, such as financial management applications, run on the PC 800 . To provide a layer of security for these communications, the business application integration module 540 can cooperate with the security module 570 to regulate the type of information that can be shared by the set-top box 500 , the profile 400 and the other financial management applications. For example, the profile 400 can be associated with a number of rules governing who has access to one or more portions of information, who can spawn customer service applications, who can authorize use of funds, or in general any rule that governs, regulates, restricts or allows access to one or more of information within the profile, applications on the set top box, or communications for the set-top box 500 to an entity connected to network 10 .
[0098] The social network application module 545 in a similar manner cooperates with the profile 400 and set-top box 500 to allow the use of personalized information and personal preferences as contained in the profile 400 to provide a richer social networking environment. For example, social networking applications used in conjunction with the set-top box 500 allow the user to experience two-way, full-motion high-definition video content as well as enhanced security. For example, storing personalized information and personal preferences in the profile 400 can provide a layer of security above that which is typically associated with a web presence. The disclosure, query or access to information in the profile 400 can be based on one or more of a trust relationship with one or more trusted entities, analysis by the intelligent agent, or rules associated with a profile, or a master profile. The push of security information such as DCAS makes the environment associated with the use of the profile 400 significantly safer. As discussed above, social networking applications can be established on a hierarchical basis where, for example, parents would be able to set certain conditions, limits or thresholds for children using a social networking applications to add safety and age appropriate rules governing use of the applications, as well as access to information within the profile and restrictions on access to the various types of service applications available to that particular user.
[0099] The set-top box environment also provides the ability to utilize two-way, full-motion video, in addition to high-definition video, and does not suffer from the drawbacks associated with typical internet-based applications, such as latency, dropped frames, and the like. The social network application module 545 is thus capable of providing interaction with one or more other participants that is more like a face-to-face interaction.
[0100] As with the other modules, the social network application module can benefit from the various information stored on the profile 400 and features of the set-top box 500 such as communications, preferences, alternate contact modalities, payment preferences, priority preferences, trusted contact information, personal information, business information, or the like. The ability to integrate the personal information stored in the profile 400 with one or more social networking applications associated with the social network application module 545 provides the ability to enhance a user's experience.
[0101] In general, any application stored in a social network applications module 545 can be used for social networking. These applications can include any type of communications modality such as video, text, image sharing, or the like, in either a one-directional, two-way or multiparty format. For example, multimedia versions of social networking applications can also be used that combine one or more of the above with such functionality, as, for example, blogging, real-time white-boarding, chatting, video conferencing, or in general, any multimedia application between one or more parties.
[0102] The SIP functionality/integration module 565 allows one or more SIP-based communications to be used in conjunction with the set-top box 500 and profile 400 . These SIP-based communications could be run in parallel with various applications run on the set-top box 500 and, as discussed above, can be bound to one or more other devices such a telephone, PDA, home phone, business phone, or in general any SIP-enabled device. In addition to being able to run in parallel with one or more applications on the set-top box 500 , upon execution of a specific customer service application initiated in the set-top box, a SIP communication could be established and, once active, the corresponding communication on the set-top box could optionally be terminated.
[0103] Security module 570 can provide varying levels of security for the information within the profile 400 . Furthermore, as previously discussed, a hierarchical security platform can be established with, for example, a master profile that regulates dependent profiles, such as those that would be established by parents for their children. Extending this basic concept to a business environment, business managers could also set up various rules in conjunction with the security module 570 regulating the control, access to, and usability by employees of information stored in the profile 400 .
[0104] In general, since any information can be stored in the profile 400 , various rules, policies, profiles, and the like, can be established that govern not only access to, but dissemination of the information within the profile. For example, access to the various types of information in the profile can be regulated based on who is trying to access the information, what type of information is being accessed, what the accessed information is going to be used for, and the like and can be analyzed by the security module 570 to determine whether that access or dissemination should be allowed. For example, the security module 570 can cooperate with the intelligent agent module 580 to assist with analysis of any security risks that may be associated with providing access to the information within the profile 400 .
[0105] Communications applications module 575 enables various types of communications application to be used with the set-top box 500 . These communications include, for example, audio communications, video communications, chat communications, telephony-type communications, or in general any communication between the set-top box and, another entity on the network, with one or more of the devices associated with and connected to the set-top box, to another entity on the network, or communications associated with a bound device, such a bound IP soft phone.
[0106] Intelligent agent module 580 is a software agent that assists users with various functions and is capable of acting on their behalf in an automated or semi-automated manner. Intelligent agent module 580 is thus capable of cooperating with one or more of the other modules in the set-top box, or devices connected to the set top box, and based on information and/or rules within the profile 400 , to perform various actions. The actions can be triggered by one or more triggering events that may be based on information received by the set-top box, or information sent to an entity on the network 10 . For example, upon receiving a new program schedule, the intelligent agent could parse the various shows that are scheduled to be shown within the next week, and knowing, based on information within the profile 400 , if their user is a fan of a particular actor, automatically docket the recording of the movie featuring the actor.
[0107] As another example, the intelligent agent module 580 can monitor the various interactions between the set-top box and entities on the network 10 . If, for example, a parent has established restrictions on social networking applications associated with a child, and the intelligent agent module 580 detects that the child is attempting to access one of these social networking applications on the prohibited list, the intelligent agent module can spawn a communication to the parent indicating such an attempt. For example, the intelligent agent module can cooperate with an email or call spawning module and, for example, send a text message to the parent indicating that the child was trying to access a prohibited social networking application at a given date and time. This can be enabled with cooperation of the SIP functionality module 565 and the text message sent to a SIP enabled endpoint. At the same time, a communication could be established between the SIP endpoint and the set-top box, and if the SIP endpoint is video enabled, real-time communications could be established between the parent and child to discuss their activities.
[0108] FIG. 3 outlines an exemplary profile 400 . The exemplary profile 400 comprises one or more of business, personal, and entity information 410 , communications preferences 420 , personal preferences 430 , payment information 440 , vendor information 450 , priority information 460 , contextual preferences and sub-profiles 470 , alternate contact modalities 480 and one or more trusted contacts 490 .
[0109] As discussed, one ore more of the personal, business and entity information can include any information that a user would like to store. For example, examples of personal information include name, address, credit card information, banking information, movie preferences, communications preferences, restaurant preferences, vendor preferences, billing preferences, and the like. Examples of business information includes, for example, preferred vendors, banking information, communications preferences, ordering or inventory information, employee information, payment information, accounting information, business management information, or in general any information related to a business. Entities can also include information about items such as groups of individuals, groups of businesses, or in general any entity that may not be personal or business in nature. Interfaces that can be provided that provide access to the information stored within the profile, and this information can be edited, updated or deleted as appropriate. The editing, updating or deleting of this information can be performed via an interface on the set-top box, or via any interface connected to the set-top box. This access to the information within the profile can be password protected, and the information can be transferred via or in accordance with well known encryption techniques and standards.
[0110] The communications preferences 420 provide to the user the ability to store various types of communications preferences or modalities that can effect not only the type of communication to use to access the user, e.g., video, chat, IM, telephone, or the like, but that can also be used in conjunction with presence information and/or communication routing.
[0111] The personal preferences 430 are a set of rules related to a particular user's personal preferences. These personal preferences can relate to any functionality of the set-top box, display characteristics of the STB, operation of the STB, or the like, and can be related to any one or more of menu options, communications preferences, contact preferences, set-top box management, or the like.
[0112] Vendor information 450 stores various information that can be used for payment of goods and/or services ordered through or in conjunction with the set-top box. This payment information can have a higher security level than other types of information within the profile 400 , such that, for example, a password is required before the purchase for goods and services can be made. Additionally, the payment information could be limited to use by the contact/service provider 300 .
[0113] Vendor information 450 can include such information as preferred vendors, vendors who should not be used, historical purchase information, account information, reference information associated with a particular vendor, or in general any information associated with a vendor. When new vendors are utilized, and in conjunction with the intelligent agent module 580 , new information can be added to the vendor information 450 and stored in the profile 400 .
[0114] In addition, also in conjunction with the intelligent agent module 580 , the vendor information 450 can be dynamic such that as, for example, a user accesses a particular vendors website, account information can be populated into the vendor information 450 such as order placed, remaining balance, special offerings, or in general any information associated with that particular vendor.
[0115] Priority information 460 includes any information, such as rules, that can be used to assist with prioritizing certain activities, applications, or in general, any functionality associated with the set-top box 500 . This priority information 460 could also be used in conjunction with the intelligent agent module 580 to assist with determining prioritization of certain activities.
[0116] The contextual preferences and sub-profiles 470 establishes preferences based on context that could also be categorized as sub-profiles depended upon, for example, a particular application being run on the set-top box 500 . As with the other types of information, the contextual preferences 470 can be used in conjunction with the intelligent agent module 580 to provide dynamic application behavior.
[0117] The alternate contact modalities 480 outline various contact modalities for a particular user. These alternate contact modalities 480 can be used with the communication preference information, personal preference information and/or priority information to assist with completion of an incoming communication to an endpoint. For example, based on information in the alternate contact modalities profile, one or more of the binding module and SIP functionality module can be utilized to complete an incoming communication to an endpoint where the user is located.
[0118] Trusted contacts 490 include information regarding one or more entities that are trusted. For example, an entity can be trusted if it is approved by the content/service provider 300 . Additionally, an entity can be trusted if, for example, the user has had previous interactions with the entity and has identified them it as being trusted.
[0119] Optionally, the intelligent module 580 can also be used to analyze transactions with a particular entity, and upon, for example, a threshold number of transactions being completed in a satisfactory manner, the entity can be identified as “trusted.”
[0120] The trusted entities need not be limited to businesses that sell goods and/or services, but can also include entities such as schools, other individuals, or in general any one or any entity that is identified as being trusted. For example, in a social networking environment, parents can establish rules that can identify certain chat groups or other users that are trusted. In conjunction with the intelligent module, for example, a child can request a parent to approve a specific entity as trusted, and communications with that entity are restricted until it is approved by that parent.
[0121] Trusted status can also be achieved by, for example, the intelligent agent module 580 analyzing an entity's, user's or merchant's feedback. Upon a merchant having reached a threshold level of feedback, the agent can identify the merchant as “trusted” which could then, optionally, forward the “trusted” identification to an additional entity, such as a parent, for final approval.
[0122] FIG. 4 outlines an exemplary method for profile management. In particular, control begins in step S 100 and continues to step S 110 . In step S 110 , an interface is provided that allows for one or more of creation and editing of a profile. Next, in step S 120 , an option is provided for editing or creating a new profile. Then, in step S 130 , and optionally based on password verification, creation, editing or updating of the profile is allowed. Control then continues to step S 140 .
[0123] In step S 140 , the profile is saved. Next, in step S 150 , a determination is made whether to edit or create another profile. If editing or creation of another profile is desired, control jumps back to step S 120 , with control otherwise ending in step S 160 .
[0124] FIG. 5 outlines an exemplary method for a service transaction. In particular, control begins in step S 200 and continues to step S 210 . In step S 210 , a service transaction is initiated on or in association with the set-top box. As will be appreciated, the original request for initiation of a service transaction can come from one or more of the attached or associated devices such as a TV, personal computer, or the like. As previously discussed, this service transaction could also be initiated from an associated device, such as a SIP enabled communications device.
[0125] In step S 220 , a web service request is triggered by, for example, a menu based request that has stored information that can be derived from, for example, the stored profile. Next, in step S 230 , a determination is made whether another device, such as a communication device, should be bound to the service transaction. If another device should be bound to the service transaction, control jumps to step S 240 where the communication device is bound, and for example, a call is spawned from that device.
[0126] Otherwise, control continues to step S 250 , where profile information is used to assist with completion of the web service request. Control then continues to step S 260 where the control sequence ends.
[0127] FIG. 6 outlines an exemplary exchange between the set-top box and a service provider. This exemplary exchange could be utilized upon the initiation of a service request from a user associated with a set-top box to a goods and/or services provider. In particular, control begins in step S 300 and continues to step S 305 . In step S 305 , a service request is initiated. As will be appreciated, this could also be a request for goods or in general a request for anything. Next, in step S 310 , the service request is received. Then, in step S 320 , a check is made to determine that the service availability is present. Control then continues to step S 330 , where the profile information stored on the set-top box is requested based on, for example, information in the service request. Next, in step S 315 , the requested information is retrieved. Next, in step S 325 , the requested information can be filtered based on one or more of preferences, personal preferences, contextual preferences, sub-profiles, analysis by one or more of a security agent or intelligent agent, or in general any filtering criteria. The filtered information is then forwarded to the service provided in step S 335 . Next, in step S 340 , the profile information is received. Then, in step S 350 , the service request is initiated. Control then continues to step S 360 .
[0128] In step S 360 , the coordination of the supply of goods and/or services can optionally be coordinated with, for example, an outside party, such as a trusted entity. Then, in step S 370 , the service is provided to the user, with control then continuing to step S 345 where the control sequence ends.
[0129] FIG. 7 outlines an exemplary method for analyzing incoming information and the use of an intelligent agent. In particular, control begins in step S 400 and continues to step S 410 . In step S 410 , one or more types of information, such as information incoming to the set-top box, information from the set-top box, and information received from a user, can be analyzed. Next, in step S 420 , a determination is made whether to invoke the intelligent agent based on this analysis. This analysis can be based on, for example, logic in the form of one or more of neural networks, expert systems, key word searching, or the like. If the intelligent agent is to be invoked, control jumps to step S 440 with control otherwise continuing to step S 430 where the control sequence ends.
[0130] In step S 440 , the intelligent agent is activated. Inputs to assist the intelligent agent with determining an appropriate action can include one or more of profile information, security information, and rules, and can also be based on queries that are spawned to, for example, an end user. Control then continues to step S 450 .
[0131] In step S 450 , the information that triggered the spawning of the intelligent agent is analyzed, and utilization of profile information, security information, rules, query responses and the like is taken into consideration for an appropriate action. Next, in step S 460 , the action is performed, with control continuing to step S 470 where the control sequence ends.
[0132] FIG. 8 outlines an exemplary method for business profile interaction according to this invention. In particular, control begins in step S 500 and continues to step S 510 . In step S 510 , a determination is made whether a business profile is being used. If a business profile is being used, control jumps to step S 530 , with control otherwise continuing to step S 520 where the control sequence ends.
[0133] In step S 530 , a determination is made whether one or more of a business profile and rule is requesting access to a business application. If the determination result is yes, control jumps to step S 540 , with control otherwise continuing back to step S 520 where the control sequence ends.
[0134] In step S 540 , the business profile and/or rule information is integrated with one or more business applications. Next, in step S 550 , information can optionally be exchanged between the profile and business applications. Then, in step S 560 , the profile can optionally be updated with information received from the one or more business applications. In a similar manner, information from the profile can be used to update the one or more business applications with selected information. Control then continues to step S 570 where the control sequence ends.
[0135] FIG. 9 illustrates an exemplary method of social networking utilizing the set-top box and profile(s) associated therewith. In particular, control begins in step S 600 and continues to step S 610 . In step S 610 , one or more social networking applications are initiated with their corresponding interfaces. Initiation of the various social networking applications can be limited by information in the profile, security information, and/or rules. For example, as discussed above, parental controls may be input into the rule set, thereby restricting the type of social networking application that can be available to certain users. This type of restrictive rule can be placed in the master profile, with a hierarchical rule set that governs all subordinate profiles. Next, in step S 620 , interactions with one or more social networking applications can be monitored for compliance with security information, the rules, and, for example, information in the profile. The various types of interactions include two-way video, high definition video, interactive media, enhanced blogging, text messaging, chat, or in general, any communication modality. Control then continues to step S 630 .
[0136] In step S 630 , the disclosure of sensitive information is regulated by the intelligent agent with reliance on the rules, security information, and type of profile. For example, as previously discussed, if this is a child's profile, a parent can apply various rules and security information that regulates the disclosure of sensitive information, with, in step S 640 , a determination being made, upon violation of one or more of the security information and rules, of whether an alert should be sent. If an alert should be sent, control continues to step S 650 where an alert is prepared and sent. Otherwise, control jumps to step S 660 .
[0137] In step S 660 , an option is provided to manage or update the profile. If managing or updating is required, control continues to step S 670 , with control otherwise jumping to step S 680 where the control sequence ends.
[0138] In step S 670 , updating and/or management of the profile is allowed. This updating or management can be user-centric, for example, if a user wants to add another social networking application to a trusted category, update personal information, update payment information, or in general update any information associated with the profile. In addition, the profile can also be managed by a superior profile holder, such as a parent, as appropriate.
[0139] FIG. 10 illustrates an exemplary method for initiating a transaction in greater detail. In particular, control begins in step S 700 and continues to step S 705 . In step S 705 , one or more communications devices or other electronic devices are associated with the STB. For example, a phone number or other identifier can be stored in the profile with an indication that the device associated with that identifier or phone number is associated with the STB. This activity could be user centric, in association with the service provider, or in general, through any process. Next, in step S 710 , a transaction is initiated. Depending on whether a personal agent or a service provider agent is being used for the particular instance of the invention, control continues to either step S 712 or step S 715 , respectively.
[0140] In step S 715 , a desired transaction is selected. This desired transaction can be selected from a list of available transactions, or, for example, a user can navigate via a web-based service to find merchants, service providers, or the like, with which they would like to initiate a transaction. Next, in step S 720 , the service agent looks up the STB and retrieves information, such as payment information, from the profile. Then, in step S 725 , the service agent forwards the transaction information and payment information to the business providing the requested service. Control then continues to step S 730 .
[0141] In a similar manner, in step S 712 , a desired transaction is selected in cooperation with a personal agent. As with the transaction request to a service provider, the selection of the desired transaction can be either from one or more of canned transactions, or navigated to, based on, for example, web navigation. Next, in step S 714 , the personal agent forwards the transaction information and payment information to the business providing the requested service. The transaction information can include such information as the name of the person placing the order, address, phone number, order options, and in general any information associated with an order. Control then continues to step S 730 .
[0142] In step S 730 , a determination is made whether the transaction information is to be stored. If the transaction information is to be stored, control continues to step S 735 with control returning to step S 740 .
[0143] In step S 740 , a determination is made whether another transaction is desired. If another transaction is desired, control jumps to step S 750 , with control otherwise ending at step S 745 .
[0144] In step S 750 , a determination is made whether a previous transaction should be reused. If it is to be reused, control continues to step S 755 with the selection and retrieval of the previous transaction, with control continuing in step S 760 to either step S 725 or step S 714 as appropriate.
[0145] If a previous transaction is not to be reused, control continues to step S 765 where control returns to either step S 715 of step S 712 , as appropriate.
[0146] FIG. 11 illustrates in greater detail storing information regarding the transaction of step S 735 . In particular, control begins in step S 800 and continues to step S 810 . In step S 810 , the stored transaction information trigger is detected. For example, upon completion of a transaction, the user can be queried as to whether they would like to store the transaction. Next, in step S 820 , information regarding the transaction can be stored in one or more of the STB, service provider network, and communications device, depending on, for example, whether a personal agent or service agent is being used and whether the device from which the transaction request was sent is able to store the transaction information. Then, in step S 830 , a determination is made whether the information should be stored on the communications device. If the information is to be stored on the communications device, control continues to step S 835 . Otherwise, control jumps to step S 845 .
[0147] In step S 835 , an agent sends a configuration request to the phone. Next, in step S 840 , the menu item is populated on the phone with control continuing to step S 845 .
[0148] In step S 845 , a determination is made whether the transaction information should be stored on the service provider network. If the transaction information is to be stored on the service provider network, control continues to step S 850 , with control otherwise continuing to step S 860 .
[0149] In step S 860 , a determination is made whether to store the transaction information on the set-top box, e.g., in a profile. If the transaction information is to be stored on the set-top box, control continues to step S 865 . Otherwise, control jumps to step S 875 .
[0150] In step S 865 , an agent sends a configuration request to the set top box. Next, in step S 870 , the menu item is populated on the menuing service, with control continuing to step S 875 .
[0151] In step S 875 , the menu item is made available for subsequent transactions. Control then continues to step S 880 where the control sequence ends.
[0152] FIG. 12 illustrates in greater detail a social networking application associated with an exemplary embodiment of the present invention. In particular, control begins in step S 900 and continues to step S 910 . In step S 910 , one or more buddy lists of one or more buddies are created. Next, in step S 920 , one or more of rules, rights, and preferences are associated with the one or more buddies. Then, in step S 930 , the status of one or more buddies can optionally be populated on the user's device. In a similar manner, the status of the user can be pushed to other users' devices and their status provided thereon. Control then continues to step S 940 .
[0153] In step S 940 , one or more of audio, video and multi-media content can optionally be rendered on other buddies' devices. Snapshots or screen captures or audio sub-clips can also be provided to the other buddies. Next, in step S 950 , information can be exchanged among the buddies via one or more of text messaging, chat, or any other known methods of exchanging information between devices. Control then continues to step S 960 where the control sequence ends.
[0154] Below are examples of transactions, the setup of these transaction and options for performing the transaction according to exemplary embodiments of this invention.
[0155] In accordance with a first exemplary scenario, a user is assumed to either have a cell phone provided by a service provider or to have a cell phone number that is associated with the phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the service provider so that calls from that cell phone can be associated with that user and their specific STB. A user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time when they make a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, then at a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user can use their cell phone and call the personal agent phone number associated with the STB. The call to the personal agent results in a voice menu being presented to the user from which the user can select the desired transaction orally, for example with the assistance of an agent or an IVR-type system. This request is then sent from the STB with secure payment information to the business providing the requested service for the transaction.
[0156] In another exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number that is associated with the phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the SP so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time, when they make a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, then at a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone and calls a service provider agent service phone number that is associated with a set of servers in the service provider network. The call to the service agent results in the user being presented with a voice menu from which the user can select the desired transaction either orally or based on keyed-in responses. The service agent then uses the association of the cell phone with the user to determine the STB for the user, and then uses this information to launch a secure fetch of the payment information and to send the transaction request to the business providing the requested service for the transaction.
[0157] In yet another scenario, a user is assumed either to have a cell phone or some other type of communication device provided by the service provider or to have the cell phone number of the device specially stored as a contact in their profile. In the later case, an agent in the STB shares the cell phone data with a server in the service provider system so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time, when the user makes a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference to be used in the future. If the user indicates that they would like to store this transaction, the agent sends a configuration request to the user's cell phone so that a menu item associated with the preference is created on the cell phone and made easily accessible in the future. At a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone menu button to indicate the request to a set of servers in the service provider network. The request launches a secure fetch of the payment information and sends the transaction request to the business providing the requested service for the transaction.
[0158] For another exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number of the cell phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the service provider network so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At a later time, when the user makes a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, the agent sends a configuration request to a server in the SP network that provides service menuing to the cell phone. At a still later time when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone to access their menuing preferences stored in the SP network. They select the menu button for the desired transaction, which indicates the request to a set of servers in the SP network. The request launches a secure fetch of the payment information and sends the transaction request to the business providing the requested service for the transaction.
[0159] Below are examples of social networking applications based on exemplary embodiments described herein.
[0160] In a first exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number of the cell phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the SP so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At a later time, the user indicates, either in their preferences, via a web transaction, or via a cell phone menu, that a group of other SP users are “buddies” of the user. Any user can have a number of buddy groups, and other users can be members of multiple buddy groups for the same user or for different users. A specific buddy group makes up an instance of a social network for the user.
[0161] Using methods well known in the art, the presence of each user in the buddy group can be exposed in real-time to the whole group. (Watching a television program, or currently mobile, busy, or off-line, are examples of buddy states). The STB social network agent provides an interface to indicate the buddy state to a network server and to provide the ability to render the state of the user's buddies over the top of a program that the user is viewing. The agent is capable of rendering video and/or audio of both the viewer and the program being viewed to the network server. The network server can in turn render the video and audio in an appropriate format to the other buddies in the users' currently selected group while respecting any copy restriction flags in the program material sent to it. The social network agent in the STB, and an appropriate client in the cell phone then make it possible for the buddies to share their thoughts, feelings, and reactions to the program being watched. Their interaction can be stored on the network server to be accessible to the other buddy list members. Optionally, the conversation can be tagged and made available for search and access by other members of the social network service being provided by the enterprise. Some service providers may give to active buddy groups privileged access to desired material in order to generate interest in the material by other groups.
[0162] A number of variations and modifications of the invention can be used. It would be possible to provide for some features of the invention without providing others.
[0163] The exemplary systems and methods of this invention have been described in relation to STB's and profile(s). However, to avoid unnecessarily obscuring the present invention, the description omits a number of known structures and devices. This omission is not to be construed as a limitation of the scope of the claimed invention. Specific details are set forth to provide an understanding of the present invention. It should however be appreciated that the present invention may be practiced in a variety of ways beyond the specific detail set forth herein.
[0164] Furthermore, while the exemplary embodiments illustrated herein show various components of the system collocated, certain components of the system can be located remotely, at distant portions of a distributed network 10 , such as a LAN, cable network, and/or the Internet, or within a dedicated system. Thus, it should be appreciated, that the components of the system can be combined in to one or more devices, such as a STB, or collocated on a particular node of a distributed network, such as an analog and/or digital communications network, a packet-switch network, a circuit-switched network or a cable network.
[0165] It will be appreciated from the preceding description, and for reasons of computational efficiency, that the components of the system can be arranged at any location within a distributed network of components without affecting the operation of the system. For example, the various components can be located in a switch such as a PBX and media server, gateway, a cable provider, in one or more communications devices, at one or more users' premises, or some combination thereof. Similarly, one or more functional portions of the system could be distributed between a communications device(s), such as a STB, and an associated computing device. The one or more functional portions of the system could be also be installed in a TV or TV tuner card, such as those installed in a computer.
[0166] Furthermore, it should be appreciated that the various links, such as link 5 , connecting the elements can be wired or wireless links, or any combination thereof, or any other known or later developed element(s) that is capable of supplying and/or communicating data to and from the connected elements. These wired or wireless links can also be secure links and may be capable of communicating encrypted information. Transmission media used as links, for example, can be any suitable carrier for electrical signals, including coaxial cables, copper wire and fiber optics, and may take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications.
[0167] Also, while the flowcharts have been discussed and illustrated in relation to a particular sequence of events, it should be appreciated that changes, additions, and omissions to this sequence can occur without materially affecting the operation of the invention.
[0168] In yet another embodiment, the systems and methods of this invention can be implemented in conjunction with a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device or gate array such as PLD, PLA, FPGA, PAL, special purpose computer, any comparable means, or the like. In general, any device(s) or means capable of implementing the methodology illustrated herein can be used to implement the various aspects of this invention. Exemplary hardware that can be used for the present invention includes computers, handheld devices, telephones (e.g., cellular, Internet enabled, digital, analog, hybrids, and others), and other hardware known in the art. Some of these devices include processors (e.g., a single or multiple microprocessors), memory, nonvolatile storage, input devices, and output devices. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, or virtual machine processing can also be constructed to implement the methods described herein.
[0169] In yet another embodiment, the disclosed methods may be readily implemented in conjunction with software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized.
[0170] In yet another embodiment, the disclosed methods may be partially implemented in software that can be stored on a storage medium, executed on programmed general-purpose computer with the cooperation of a controller and memory, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated measurement system, system component, or the like. The system can also be implemented by physically incorporating the system and/or method into a software and/or hardware system.
[0171] Although the present invention describes components and functions implemented in the embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. Other similar standards and protocols not mentioned herein are in existence and are considered to be included in the present invention. Moreover, the standards and protocols mentioned herein and other similar standards and protocols not mentioned herein are periodically superseded by faster or more effective equivalents having essentially the same functions. Such replacement standards and protocols having the same functions are considered equivalents included in the present invention.
[0172] The present invention, in various embodiments, configurations, and aspects, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, configurations, and aspects, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
[0173] The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects of the invention may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.
[0174] Moreover, though the description of the invention has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter. | Utilization of stored of personalized information and communication preferences in a profile in a STB in a structured format or via cookies allows at least a combination of feature rich telephony applications, with the personalized data stored in STBs facilitating feature rich communications sessions. Providing advanced multimedia communications applications using personalized data resident in STBs could allow an entity to provide, for example, many previously unavailable services, and therefore provide considerable new business potential. The personal information stored in the STB can convey many exemplary benefits, such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, as well as multimedia messaging, etc. The integration of the personal information with the intelligent personal agent also enhances the user experience. | 7 |
FIELD OF THE INVENTION
This invention is related generally to prevention of erosion and promotion of seed germination in soil, and more particularly, to installation of erosion blankets to prevent erosion and promote seed germination.
BACKGROUND OF THE INVENTION
Erosion blankets are used throughout the world to stabilize soil before seed germinates and/or small plant plugs cover the ground. Erosion blankets are used for a variety of reasons, such as stabilizing large areas along highways, stabilizing areas around detention/retention ponds, establishing fine quality lawns for commercial and residential properties and restoring prairies. Erosion blankets are typically provided in rolls of 65 to 100 yard rolls, depending upon the type of blanket. The most widely used blankets are made of straw and wood fiber. Typically, erosion blankets of every type are installed by hand.
Erosion blankets are typically utilized to keep the soil and seed from eroding away during and after precipitation. In addition to preventing erosion, such blankets retain moisture in the soil under the blanket for a much longer period of time. The extended presence of moisture enables the seed to germinate much more quickly than without blanket cover.
In addition, erosion blankets retard weed growth when grass seed is planted in the late spring and early summer months. Due to the consistent shade that is provided by the erosion blanket the vast majority of noxious weed seed will not germinate.
In the landscaping industry, two alternative products are often used to encourage seed germination. These products are straw mulch and hydro mulch, both of which are typically mechanically blown or dropped onto the soil. However, bales of straw which are broken apart and spread on the soil as straw mulch can blow away which leads to mixed results. Hydro mulch, a paper component with seed and fertilizer mixed in slurry of water, helps the seed germinate but does not control erosion. Furthermore, hydro mulch is a poor medium to keep moisture in the soil during critical dry times of the growing season. While straw mulch and hydro mulch are less effective than erosion blankets, their use is popular due to their lower associated costs, especially the labor costs involved in installing the mulch on the soil.
Erosion blankets are typically installed after a site has been fine graded (soil prepared for seed) and seeded. The seed may be broadcast or installed using a mechanical seeder. For use with small plant plugs, the erosion blanket is installed and the plant plugs are manually planted into the blanket. In either use, after the erosion blanket has been laid on the ground, stakes must be manually driven through the blanket into the ground to keep the blanket in correct position. The stakes are typically six inches long and must be driven deep enough such that they are flush with the erosion blanket so that mowers do not strike them. The manual operations dealing with the installation of stakes significantly increase the cost of installing an erosion blanket and often lead landscapers to use the less labor-intensive products mentioned above for reasons involving both time and costs.
Therefore, there is a continuing significant need in the field of erosion prevention and seed germination promotion for improvements related to the installation of erosion blankets and for more efficient installation thereof. An improved device and method achieving these goals would lead to better erosion protection and, therefore, higher quality lawns and prairies, as well as cleaner lakes, creeks, streams, rivers and oceans.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an improved device which efficiently installs erosion blankets.
Another object of the invention is to provide an erosion blanket installation device which is simple in structure and operation in order to facilitate effective installation.
Another object of the invention is to provide an erosion blanket installation device which mechanically drives stakes into the ground to hold the blanket in position.
Another object of the invention is to provide an erosion blanket installation device which mechanically drives staples into the ground to hold the blanket in position.
Another object of the invention is to provide an erosion blanket installation device which simultaneously unrolls and pins to the ground the erosion blanket.
Another object of the invention is to provide a method of mechanically installing an erosion blanket on the ground.
Still another object of the invention is to provide a method of installing an erosion blanket on the ground which minimizes the need for manual operations during installation.
Still another object of the invention is to provide an easy penetration point in the ground for the insertion of a stake which automatically pins an erosion blanket to the ground.
Yet another object of the invention is to provide a method of automatically pinning an erosion blanket to the ground during installation.
These and other objects of the invention will be apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
This invention is an improved method and device for efficiently and effectively installing erosion blankets on ground surfaces. The invention represents a significant advance over the state of the art by providing a novel device, which allows for an automatic method of installation which is heretofore unknown in the art.
The erosion blanket installation device is able to install a 500 yard roll of a straw erosion blanket on the ground while securing the blanket in place until the turf or vegetation naturally stabilizes the ground soil via a staple or a pneumatically driven stake which enters a 5″-6″ furrow.
The device for installing an erosion blanket, i.e., laying and securing the blanket along a pathway on the ground, is comprised of a vehicle frame, an axle arm connected with respect to the vehicle frame and engaging an axle around which the blanket roll is sleeved, at least one staple or stake gun connected with respect to the frame and at least one staple or stake cartridge connected with respect to the gun for supplying staples or stakes to pin the blanket to the ground.
The erosion blanket is rolled so that it may be sleeved around the blanket axle before use of the device. The blanket is positioned in the vehicle frame by sliding the roll around the blanket axle. As the device is propelled along the pathway the blanket is unwound from the roll and is placed on the ground. The device preferably includes a blanket guide roller for which directs the blanket to the ground upon unwinding. The gun pins the blanket in position by driving a staple or stake through it into the ground.
For use with a stake gun, rather than a staple gun, the device also preferably includes at least one furrow blade connected with respect to the frame. Preferably three furrow blades are supported by a furrow bar which is connected to a hydraulic cylinder which urges the blades into the ground. The blades furrow the ground during movement of the device and are urged to stay in position by their arcuate shape.
The preferable device includes at least one hitch connection point connected with respect to the frame. The hitch connection points are designed to connect to a hitch of a tractor or other vehicle which is able to tow the device. There are preferably three hitch connection points to provide sufficient connection to the towing vehicle.
The preferable device further includes an air compressor which is connected to each gun for forcing staples or stakes through the blanket into the ground. An air compressor is connected to each gun via a compressor hose and allows for pneumatic pinning of the blanket.
It is also preferred that the device include a retractable arm which is connected with respect to the frame. The retractable arm is movable between an open position which allows the roll to be loaded by sliding over the blanket axle and a closed position in which the retractable arm engages the free end of the blanket axle to hold the roll in place. A spring-loaded retractable-arm pin is connected with respect to the frame and pivotably supports the retractable arm with respect to the frame. A retractable-arm brace connects the retractable-arm pin to the frame. In use, the retractable arm is pivoted so that the erosion blanket may be positioned within the vehicle. After the blanket roll is in position within the device, the retractable arm is pivoted so that the second end of the blanket axle may engage the retractable arm to hold the roll in place.
In another preferred embodiment the device includes at least one compression wheel for pressing the blanket against the ground as the blanket unwinds. The compression wheel is supported by a compression-wheel frame. The compression-wheel frame preferably supports each gun and staple or stake cartridge as well.
The novel method of installing erosion blankets on ground surfaces comprises (a) propelling a blanket-laying device along a pathway, (b) rotating the roll of the erosion blanket supported in the device such that the blanket unwinds and is positioned on the surface along the pathway; and (c) in conjunction with the rotating step, mechanically pinning the blanket to the ground.
It is preferred that the rotating and pinning steps are performed simultaneously. The rotating and pinning steps are also preferably performed continuously until the roll expires. Furthermore, the rotating step is preferably performed in conjunction with, and as a result of, the propelling step. That is, the propelling of the device causes the roll to rotate and unwind. In the novel method, the blanket is preferably initially anchored to the ground surface by manually driving staples or stakes through the blanket into the yard. However, alternate embodiments of the invention allow for the blanket to be anchored to the ground without any manual manipulation.
The preferred method includes the step of pressing the blanket to the surface as it unwinds from the roll to allow for effective surface coverage. Such step is preferably performed by compression wheels, and more preferably by at least 3 axially-spaced compression wheels, e.g., one wheel pressing the left side of the blanket, one wheel pressing the middle of the blanket, and one wheel pressing the right side of the blanket.
The preferred method also includes the step of furrowing the surface before the pinning step. Such a step is preferably performed by at least 3 blades which are aligned with the means for mechanically pinning the blanket to the ground.
The device is preferably propelled along the pathway at at least about 3 miles per hour (mph). A tractor or similar vehicle can be connected to the device via a hitch in order to tow the device at the proper velocity. It is preferred that the erosion blanket is installed on the surface at a rate of at least about 400 yards every 3 minutes, or 400 feet/minute. Even more preferably, the erosion blanket is installed on the surface at a rate of at least about 500 yards every 3 minutes, or 500 feet/minute.
The pinning step is preferably performed using staples or stakes. Such staples or stakes are preferably biodegradable. The staples or stakes are preferably forced through the blanket into the ground by an air compressor included in the vehicle. As discussed above, the air compressor is connected to a gun which fires the staples or stakes into the ground. The gun is connected to a staple or stake cartridge which supplies the staples or stakes.
It is preferable that the number of staples or stakes held by the device be proportional to the length of the roll. Upon expiration of the roll positioned in the device, the preferred method includes the steps of loading staples or stakes and another roll of the blanket with respect to the device; propelling the device along a pathway; rotating the roll such that the blanket unwinds and is positioned on the surface along the pathway; and in conjunction with the rotating step, mechanically pinning the blanket to the ground.
The step of loading staples or stakes and another roll is preferably accomplished in less than about 15 minutes. The preferred method uses blanket rolls which are 500 yards long and at least 15,000 yards of blanket are installed in 8 hours.
An alternate method of installing an erosion blanket along a pathway on a ground surface comprises providing a roll of an erosion blanket; supporting the roll in a device; propelling the device in a direction along a pathway; and unwinding the roll so that the blanket covers the pathway, the device automatically pinning the blanket to the ground surface as it unrolls.
The preferred alternate method further comprises the step of pressing the blanket to the surface as it unwinds to allow for effective surface coverage. Such a step is preferably performed by compression wheels, and more preferably by at least 3 axially-spaced compression wheels.
The preferred alternate embodiment also comprises the step of furrowing the surface simultaneous with the propelling step. The furrowing step is preferably performed by at least 3 blades
The pinning step is preferably performed using staples or stakes. The staples and stakes are preferably biodegradable and are forced through the blanket into the ground by an air compressor included in, or connected to, the device.
In the preferred alternate method, the erosion blanket is installed on the surface at a rate of at least about 400 feet/minute. More preferably, the erosion blanket is installed on the surface at a rate of about 500 feet/minute.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the erosion-blanket-laying device in accordance with the invention.
FIG. 2 is a rear view of the erosion-blanket-laying device in accordance with the invention.
FIG. 3 is a view from the right side of the erosion-blanket-laying device in accordance with the invention.
FIG. 4 is a view from the left side of the erosion-blanket-laying device in accordance with the invention.
FIG. 5 is a overhead plan view of the erosion-blanket-laying device in accordance with the invention.
FIG. 6 is a detailed view of the compression wheel, gun and cartridge in accordance with the invention.
FIG. 7 is a detailed view of the compression wheel in accordance with the invention.
FIG. 8 is a detailed view of typical stakes for use with the erosion-blanket-laying device in accordance with the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a front view of the erosion-blanket-laying device 10 in accordance with the invention. Device 10 includes a frame 20 which comprises five frame supports (two external frame supports 20 a , 20 e and three internal frame supports 20 b , 20 c , 20 d ) which, as seen in FIGS. 3 and 4, extend horizontally from the front before arcing downwardly toward the rear of device 10 . Frame supports 20 a , 20 b , 20 c , 20 d , 20 e are connected by front frame crossbars 30 a , 30 b and rear crossbars 30 c , 30 d . Each frame support and crossbar is preferably 2″ by 2″ steel framing (hollow square framing with a thickness of ¼″). Alternatively, each frame support and crossbar is 90-degree angle bar. Preferably, the frame supports and crossbars are 1018 Cold Roll steel.
Connected to front frame crossbars 30 a , 30 b is a vertical stabilizer frame 24 comprising five vertical stabilizer bars 24 a , 24 b , 24 c , 24 d , 24 e . Vertical stabilizer bars 24 are preferably flat pieces which are 4″ wide, ½″ thick and 1′11″ to 2′ long. Lower end 25 b of vertical stabilizer bar 24 b is connected to hitch-connection point 35 b . Upper portion 23 c of vertical stabilizer bar 24 c is connected to hitch-connection point 35 c . Lower end 25 d of vertical stabilizer bar 24 d is connected to hitch-connection point 35 d . The three hitch connection points 35 provide for connection of device 10 to a tractor or other towing vehicle. Such a vehicle preferably has a category 2, three-point hitch and at least a 100 hp engine. All connections between frame supports 20 , cross bars 30 and hitch-connection points 35 are weldings.
As seen in FIG. 3, fixed axle arm 26 is welded to a rear portion of external frame support 20 a and extends forward. Axle arm is preferably 2″ by 2″ steel framing. Axle arm 26 includes a connection point for erosion blanket axle 92 . Preferably, blanket axle 92 is welded to axle arm 26 at distal end 92 a of blanket axle. Erosion blanket 90 (shown in FIGS. 3 and 4) is wound into a roll so it can be slipped onto blanket axle 92 when being positioned in device 10 . Blanket axle 92 is preferably made of lightweight polished steel with ⅜″ thick wall. Blanket axle preferably has a diameter of 3½″ and a length of about 6′7″. Blanket axle 92 must have sufficient strength to hold a 500 yard blanket roll which has an approximate mass of 150 lbs.
As seen in FIG. 4, retractable arm 27 is connected to external frame support 20 e through retractable arm pivot 28 so that retractable arm 27 may swing about pivot 28 . Retractable arm 27 is preferably constructed from flat bar steel. The lower end of retractable arm 27 has an opening provide for connection to the proximal end 92 b of blanket axle 92 . Pressure clips (not shown) are provided at the opening to hold the connection to blanket axle 92 in place. Such pressure clips can be opened manually in order to disconnect blanket axle 92 from retractable arm 27 .
Retractable-arm brace 29 is connected to frame support 20 e . Provided on retractable-arm brace 29 is a connection point for spring-loaded retractable-arm lock 31 . Retractable-arm lock 31 is preferably a spring-loaded pin which passes through retractable arm 27 and retractable-arm brace 29 to prevent retractable arm 27 from pivoting about retractable-arm pivot 28 . In order to load a roll of erosion blanket 90 , retractable-arm lock 31 is removed from retractable arm 27 and retractable arm 27 is pivoted about retractable-arm pivot 28 so that the lower end of retractable arm 27 is moved toward frame support 20 e . Retractable arm 27 may be suspended in the blanket loading position by connection to pin hole 32 . Erosion blanket 90 is positioned within the opening created by slipping blanket 90 over blanket axle 92 after retractable arm is pivoted out of the way. Then retractable arm 27 is pivoted back to its original locked position and proximal end 92 b of blanket axle 92 is connected to the lower end of retractable arm 27 . Retractable-arm lock 31 is reconnected to retractable arm 27 and retractable-arm brace 29 to lock blanket 90 in position.
Compression wheels 70 are connected with respect to the lower end of interior frame supports 20 b , 20 c , 20 d . Such connection is preferably through a spring-mounted piston-like arrangement (shown in FIG. 6) for reasons discussed below. Compression wheels 70 are preferably composite cement rollers epoxied with a textured rubber coating and have lengths of 9″ and diameters of 6″. The composite cement is preferably formed from poured concrete and fiberglass fibers which add strength and durability. The rubber surface is preferably ½″ thick. Wheels 70 preferably weigh about 18.5 lbs each. Compression wheels 70 rotate about compression-wheel axles 71 which pass through forked wheel brackets 72 . Compression-wheel axles are preferably of the ball bearing type.
As shown in FIG. 7, wheel brackets 72 upwardly terminate in hollow bracket shafts 73 which house springs 74 with lengths of 12″ and diameters of ¾″. Bracket shafts 73 are preferably 1⅜″ by 1⅜″ and are received within the interior frame supports 20 b , 20 c , 20 d . Springs 74 extend out of bracket shafts 73 and engage spring stops 21 which are positioned within interior frame supports 20 b , 20 c , 20 d . Thus compression wheels 70 are urged downward from frame supports 20 b , 20 c , 20 d . This configuration allows wheels 70 to support the weight of the device (approximately 1200 lbs.) while absorbing the vibrations encountered when the device is propelled along a pathway on the ground.
Mounted to the rear side 72 a of each wheel bracket 72 is a gun 60 . The mounting arrangement is preferably designed to allow for gun 60 to be easily removed from and reattached to wheel brackets 72 . Preferably, each gun 60 is connected to each wheel bracket 72 with self-locking nuts. Each gun 60 has an outer hard metal casing with an airtight finish to prevent dust and water from entering the internal motor.
Each gun 60 is powered by air compressor 40 which is secured to the top of center frame support 20 c (as seen in FIG. 5 ). Air compressor 40 is preferably comprised of a 2½ gallon steel tank with various air valves. The tank is pressurized by a compressor motor which is powered by a power take-off 45 from the tractor or other towing vehicle. Device 10 preferably includes a female power take-off fitting for connection to a male power take-off at the rear of the towing vehicle. Air-compressor hoses 41 extend from air compressor 40 and lead to guns 60 . Air compressor 40 has a preferred operating pressure of between about 75 and 115 psi. Such pressure is sufficient to force staples or stakes 61 through blanket 90 and into the ground.
Before use, the air compressor is turned on and each pneumatic gun 60 is calibrated for a predetermined tractor speed and the number of staples or stakes to be installed per yard.
Cartridge 62 is connected to gun 60 to provide staples or stakes 61 for pinning blanket 90 to the ground. For use with stakes, each cartridge 62 holds approximately 170 stakes. By firing a stake every 3 feet, 170 stakes are used for 510 feet of erosion blanket. Therefore, three cartridges 62 are loaded into each gun 60 to provide enough stakes for a 500 yard roll of erosion blanket. Stakes 60 are preferably biodegradable and breakdown in the environment after about 6 months. Each stake 60 is preferably 6 inches long.
Guide chamber 63 (best shown in FIG. 5) allows stakes 61 to be forwarded to gun 60 and set into position for “hammer,” one at a time, from the roll of stakes in cylindrical cartridge 62 . Hammer mechanism 64 shoots stakes 61 into the ground one at a time when triggered by trigger wire 65 .
Trigger wire 65 extends from hammer mechanism 64 to a position 2.87″ from each wheel axle 71 . Trigger wire 65 monitors each wheel 70 and triggers each hammer mechanism 64 every two revolutions of each wheel 70 (approximately every 3′ the device travels). The middle trigger wire (connected to middle gun 60 c ) is preferably offset from the outer trigger wires (connected to outer guns 60 b , 60 d ) by 1½ so that staples or stakes 60 are fired into blanket 90 in a pattern which more strongly secures blanket 90 to the ground.
Blanket guide roller 80 (FIGS. 3 and 4) is connected with respect to axle arm 26 and exterior frame support 20 e . Guide roller 80 rotates about roller axle 81 which connects to roller bracket 82 and axle arm 26 through greased ball bearing fittings. Guide roller 80 preferably is lightweight steel with a ⅜″ thick steel wall cylinder with a ¼″ thick textured rubber surface covering. Roller axle 81 is preferably a 1″ ball bearing axle. Roller bracket 82 is connected to exterior frame support 20 e . When blanket 90 unwinds, it is directed between guide roller 80 and frame supports 20 b , 20 c , 20 d . Blanket 90 is then directed downward to compression wheels 70 where blanket 90 is positioned on the ground surface.
Furrow bar 50 is pivotally mounted with respect to exterior frame supports 20 a , 20 e (shown in FIGS. 3 and 4) and supports three furrow blades 55 . (shown in FIGS. 1 and 2 ). Each furrow blade 55 is aligned with a compression wheel 70 and gun 60 . Each furrow blade 55 is preferably formed from A-36 Steel or a chromium based hardened steel. The blades 55 must be durable and replaceable in case of breakage. Each blade 55 is preferably 9″ long and curved forward so that it digs into the ground during the forward motion of device 10 .
Furrow bar 50 is preferably primarily 1″ by 1″ steel with ends which are ¾″ diameter cylindrical steel to allow for pivoting with respect to device 10 . Furrow bar 50 is pivotally attached to exterior frame supports 20 a , 20 e (shown in FIG. 5 ). Furrow bar 50 is not attached to wheel bracket 72 . A 1″ by 1″ by 4″ piece of steel is welded at the end of furrow bar 50 to attach to a commercially available hydraulic cylinder 58 with a steel eye bracket. The upper end of hydraulic cylinder 58 is connected to axle arm 26 with another steel eye bracket. Hydraulic hose 59 extends from the upper end of cylinder 58 and leads to a hitch connection point. A hydraulic control lever is positioned near the driver's seat in the tractor (not shown) so that the driver may activate the cylinder to raise or lower furrow bar 50 and, thus, furrow blades 55 .
The total weight of the preferred device (including a 500 yard blanket roll) is approximately 1250 lbs. The total weight of the alternative device which uses 90 degree angle steel is approximately 975 lbs.
In order to begin use of the erosion blanket installation device, an erosion blanket roll must first be loaded into the device. The end of the blanket roll is threaded over the guide roller and under the compression wheels and is then manually stapled or staked into place by hand. This is done to ensure that the end of the roll stays in place and the roll unwinds properly as the device is towed forward. The tractor driver will lower the furrow blades via the hydraulic control lever mounted near the driver's seat. The blades cause the device to rise about 6″ from the ground. Then the driver will engage the power take-off which powers the air compressor.
For use with stakes, a furrow blade preferably readies the ground for penetration. Once the tractor begins towing the device at the predetermined speed, the furrow blades will immediately dig into the ground to a depth of 5″ to 6″ and the device will be lowered onto the spring-loaded compression wheels. Because blanket 90 is positioned between wheels 70 and the ground, blanket 90 will unroll. At the same time, three guns 60 will fire stakes 62 through blanket 90 into the furrows in the ground. Stakes 62 lock in the ground and anchor the blanket in place until turf or vegetation grows through blanket 90 and naturally stabilizes the ground.
When the roll expires, another blanket roll is installed in the device and the cartridges are refilled. The end of the new roll is again manually stapled or staked and the process is repeated.
Use of the novel device with a tractor connected via a three-point hitch allows an erosion blanket to be installed and stapled or staked in place with 3 rows of staples or stakes. A 500 yard erosion blanket roll can be installed and sufficient staples or stakes can be reloaded in the device in 15 minutes. Such a device allows two people to install a 500 yard roll in the device. For use with stakes, the device preferably creates 3 rows of 6″ deep furrows into which the 6″ biodegradable stakes are driven by a pneumatic gun. Such furrows are created by 9″ curved blades connected to the bottom of the device. Furrows are not necessary for use with staples.
Thus, it should be apparent that there has been provided, in accordance with the present invention, a novel device for efficiently and effectively installing erosion blankets on ground surfaces that fully satisfies the objectives and advantages set forth above.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | An improved device and method for mechanically installing erosion blankets on a ground surface. The device holds a roll of an erosion blanket and provides that the blanket unwind when the device is propelled forward. Upon unwinding, the device positions the blanket on the ground and pins the blanket in position using staples, stakes or the like. Preferred embodiments of the device provide for furrowing of the ground before installation of the blanket. | 4 |
BACKGROUND OF THE INVENTION
In large buildings, such as office buildings, the core of the building is generally isolated from external environmental conditions. As a result, the core of a building is usually cooled year-round due to the heating load of the lights, machinery and personnel while the periphery of the building is heated or cooled, as required. Thus, in such buildings, there is ordinarily a concurrent demand for cooling and heating and/or neutral air to provide temperature regulation and to overcome air stagnation.
Various configurations have been employed to meet the differing demands of different parts of the system. In constant volume systems, a constant delivery fan is used to provide a constant air flow with the character/temperature of the flow being thermostatically controlled. In variable volume systems, many means are used to control fan volume. The fan speed of a variable speed fan can be varied to maintain static pressure requirements while the individually controlled dampers regulate the flow in each zone. Other means of control are riding the fan curve, using inlet guide vanes and using discharge dampers. Additionally, in conventional variable volume systems, only cooled or neutral air is circulated in the system. At locations where heating is required, a local heat source, such as an electric resistance heater, is provided. The air to be heated is provided from a separate source, such as the ceiling plenum, and requires additional fans.
In variable air volume systems where the air flow to each zone is controlled at the conditioning unit, each zone generally has a plurality of air outlets but a single sensor. The single sensor determines the amount of neutral or conditioned air supplied to each zone and is influenced by the cumulative flow through the various air outlets in each zone. The satisfactory operation of such a system requires that the demand required by each air outlet be somewhat uniform. Contrary to this requirement is, for example, a conference room located in a zone and defining a subzone. The infrequent use of such a room, coupled with high attendance when used, would generally find the room in either an overcooled/overheated condition or unsatisfied. An unsatisfied cooling condition would be exacerbated if the occupants of the zone were concentrated in the conference room since demand would be lessened at the zone sensor location. Other areas are corner rooms which have different sun loads, wind exposure etc., than occur in some or all of the other parts of the zone.
SUMMARY OF THE INVENTION
The present invention is directed to a subzone control which makes a zone sensor responsive to conditions in a subzone in an area remote from the zone sensor. More specifically, the delivery of neutral or conditioned air is diverted to the subzone requiring an increased delivery at the expense of the area in which the zone sensor is located. Since the zone sensor will indicate a need for a greater delivery to the zone, the air handling unit will be required to increase the delivery and thereby provide sufficient flow for the entire zone including the subzone.
It is an object of this invention to provide a method and apparatus for providing a subzone with required amounts of neutral or conditioned air.
It is another object of this invention to provide a method and apparatus for providing a sufficient flow of neutral or conditioned air to a subzone or area remote from a zone sensor.
It is a further object of this invention to provide an increased flow of neutral or conditioned air to a zone to accomodate increased demand in a subzone remote from the zone sensor.
It is an additional object of this invention to divert the flow of neutral or conditioned air in a zone such as to change the zone sensor's input to the control for the air handling unit. These objects, and others as will become apparent hereinafter, are accomplished by the present invention.
Basically, the delivery of neutral or conditioned air to a zone is at least partially diverted at a point upstream of a zone sensor. The diversion is in response to a need for an increased delivery of neutral or conditioned air to a subzone or area remote from the zone sensor. The resultant reduced delivery to the area in which the zone sensor is located causes the zone sensor to indicate a need for an increased delivery of air to the zone. Responsive thereto, the air handler is caused to increase the delivery of neutral or conditioned air to the zone so as to provide sufficient flow to the entire zone including the subzone.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the present invention, reference should now be made to the following detailed description thereof taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic representation of an air distribution system using the present invention;
FIG. 2 is a schematic representation of the present invention;
FIG. 3 is a first alternative arrangement of the diverter structure;
FIG. 4 is a second alternative arrangement of the diverter structure; and
FIG. 5 is a third alternative arrangement of the diverter structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a six zone distribution system 50. The variable volume multizone unit 10 supplies four perimeter zones via ducts 50a, b, c and d, respectively, and two interior zones via ducts 50e and f, respectively. The system 50 is under the control of a computer which receives temperature data from a single source in each zone and velocity/volume data for each zone. Dampers located at unit 10 control the flow to each zone. Warm, cool or neutral air is delivered to each zone of the system 50, as required.
As illustrated, the interior zone supplied by duct 50e has ten air outlets, T-1 to 10, which are not individually controlled but the total supply of neutral or conditioned air to the zone served by duct 50e is responsive to zone temperature sensor 20 and a velocity/volume sensor (not illustrated) which communicate with the computer (not illustrated) controlling unit 10. If, for example, air outlets T-6 and 7 are located in a conference room while air outlets T-1 to 5 and 8-10 are located in normally occupied offices or work areas, the actual demand in the subzone defined by the conference room can be quite different from that sensed by temperature sensor 20. Since the zone is an interior zone, cool air will normally be supplied to air outlets T-1 to 10 which will overcool the conference room when it is unoccupied. Overcooling, or overheating, might be overcome by providing for a shut off of flow to unoccupied subzones as by providing a damper which is only open when the room lights are on as an indication of the room being occupied. Assuming that conditioned air is being delivered to the conference room, the only communication of a heating/cooling demand to the sensor 20 would be as a result of the initiation of supply to the conference room which would reduce the amount of conditioned air reaching the area in which sensor 20 is located. However, because zone temperature sensor 20 is not in the conference room, it may even be subject to a reduced cooling load demand as a result of worker movement to the conference room from the rest of the zone. Any change in the supply of air to the zone is in response to the conditions sensed by sensor 20 and can cause the opening/closing of the dampers and increasing/decreasing of air delivery by the air handling unit of unit 10.
From the foregoing, it is obvious that air outlets T-6 and 7 influence the system only to the extent that they cause sensor 20 to be unsatisfied and, since they only make up 20% of the air outlets in the zone, they can only cause, at most, a 20% change in the air flow to the zone assuming that they can go between blocked/closed and fully open. Rather than bleeding off air by opening the damper(s) to air outlets T-6 and 7 and permitting otherwise unimpeded flow to air outlets T-8 to 10, the present invention diverts a portion, or even all, of the air normally delivered to air outlets T-8 to 10. The diverting of the flow has two effects. First, three air outlets T-8 to 10, are at least partially taken out of the system so that more flow is directed to all air outlets upstream of the diversion such that the conference room's share can increase to almost 30% (2/7) of the active air outlets. Second, since air delivery to the area in which sensor 20 is located is, at least, reduced, sensor 20 indicates an unsatisfied condition which results in an increased air flow to the zone.
Referring now to FIG. 2, the duct 50e forms a tee 52 having a first branch 54 and a second branch 56. Branch 54 delivers the air to the subzone defined by the conference room via outlets T-6 and 7 while branch 56 delivers the air to the outlets T-8 to 10. A splitter damper 60 is located at the intersection of branches 54 and 56. Although damper 60 is illustrated as movable between seats 61 and 62 where it respectively shuts off branches 56 and 54, mechanical stops may be provided to limit movement of the damper with respect to either or both seats. Such a stop may be fixed or adjustable as in the case of threaded member which can be advanced and retracted to engage the damper 60 over a range of positions which define a limit of movement for the damper 60. Alternatively, the movement of damper 60 can be dictated by its actuator or motor 64.
A microprocessor or computer 70 controls the movement or positioning of damper 60. Computer 70 is separate and independent from the computer which has overall control of system 50. Computer 70 receives an input indicative of the temperature in the subzone (conference room) via subzone thermostat 72 and an input indicative of the supply air temperature via temperature sensor 74. Additionally, computer 70 is in 2-way communication with actuator or motor 64 to position the damper 60, as required, and to receive a position feedback.
In operation, the temperature information supplied to computer 70 by temperature sensor 74 causes the subzone to be placed in either the heating or cooling mode. In the heating mode the zone supply air would, typically, be about 85° F. while in the cooling mode it would, typically, be about 55° F., and in the neutral mode would typically be at 70°-75° F. The subzone thermostat 72 furnishes subzone temperature information to computer 70. Assuming that temperature sensor 74 senses a temperature indicative of the cooling mode, a rise of temperature in the subzone to a predetermined setable level indicative of a cooling demand in the subzone causes computer 70 to actuate motor 64 to open the splitter damper 60. The opening of splitter damper 60 diverts or allocates more air to the subzone by opening branch 54 and correspondingly reducing the flow in branch 56. Reduced flow in branch 56 raises the temperature at the downstream location of zone sensor 20 which then indicates an unsatisfied condition to the computer controlling the overall system. The computer then increases the zone supply air by opening the zone damper and/or increasing the air handling unit output. Although there is no direct communication between the computers, the increased zone air supply is under the control of one computer but is in response to action taken by computer 70. The increased zone air supply results in an increased air supply in outlets T-1 to 10. As the subzone served by outlets T-6 and 7 becomes satisfied the position of splitter damper 60 is changed to reduce the amount of air diverted. This, in turn, increases the amount of conditioned air that reaches the location of zone sensor 20. Because there is no direct communication between the computers, they each react to the condition created by the action of the other. However, because computer 70 is able to divert flow to supply the subzone at the expense of the downstream outlets while zone sensor 20 provides the temperature information for the control of the entire zone, the satisfaction of the subzone controls the system response.
In a similar fashion, when the zone is in the heating mode, the splitter damper 60 will be controlled to divert heated air to the subzone served by air outlets T-6 and 7 if the subzone is too cool. If the demand in the subzone is different from that of the air being supplied to the zone, as sensed by temperature sensor 74, the damper 60 will be positioned to shut off, or reduce to a preset minimum, the amount of air of the wrong temperature being supplied to the subzone. Where neutral air is sensed by temperature sensor 74, it will ordinarily be diverted into the subzone in response to either a heating or cooling demand in the subzone. This is the case because neutral air is normally warmer than the heating set point and cooler than the cooling set point because it is primarily return air. It is therefore just a lower quality of heated/cooled air relative to a heating/cooling demand.
Although a single damper 60 at a tee 52 has been described, other configurations are suitable. In FIG. 3, the damper 60 has been replaced by two dampers 80 and 82 which may be either separate or linked. If separate, separate actuators corresponding to actuator 64 would be required whereas if the dampers were linked a single actuator would be required. Otherwise, the device of FIG. 3 would be the same as that of FIG. 2. As illustrated in FIG. 4, the tee 52 of FIG. 2 can be replaced with a wye 84 and two dampers 86 and 87 can replace damper 60. The dampers 86 and 87 would be operated by a single actuator 88. Otherwise, the device of FIG. 4 would be the same as that of FIG. 2. As illustrated in FIG. 5, the tee 52 can be replaced with a wye 90 and damper 60 replaced with damper 92. Otherwise, the device of FIG. 5 would be the same as that of FIG. 2.
Although preferred embodiments of the present invention have been specifically described and illustrated, other changes will occur to those skilled in the art. For example, although the invention is specifically described with respect to temperature, the sensor 20 could be responsive to another characteristic, or combination of characteristics, that go into occupant comfort and make up the load on the system such as humidity and air velocity. It is therefore intended, that the scope of the present invention is to be limited only by the scope of the appended claims. | A zone whose air supply volume and character is responsive to temperature data supplied from a single location in the zone is made responsive to the requirements of a subzone remote from the sensor location. The air supply to the subzone is changed responsive to an unsatisfied condition therein resulting in a changed supply to the area in which the sensor is located. As a result, the sensor responds to the changed air supply by indicating an unsatisfied condition to which the system responds by changing the amount of air supplied to the zone. | 5 |
FIELD OF THE INVENTION
The present invention generally relates to cementing, and more particularly to methods of improving the shelf life of a gas-generating material present in a cement composition by including a C 8 -C 18 hydrocarbon in a mixture used to coat the gas-generating material.
BACKGROUND AND SUMMARY OF THE INVENTION
The following paragraphs contain some discussion, which is illuminated by the innovations disclosed in this application, and any discussion of actual or proposed or possible approaches in this Background section does not imply that those approaches are prior art.
Natural resources such as oil and gas residing in a subterranean formation or zone are usually recovered by drilling a wellbore down to the subterranean formation while circulating a drilling fluid in the wellbore. After terminating the circulation of the drilling fluid, a string of pipe, e.g., casing, is run in the wellbore. The drilling fluid is then usually circulated downwardly through the interior of the pipe and upwardly through the annulus, which is located between the exterior of the pipe and the walls of the wellbore. Next, primary cementing is typically performed whereby a cement slurry is placed in the annulus and permitted to set into a hard mass (i.e., sheath) to thereby attach the string of pipe to the walls of the wellbore and seal the annulus. Subsequent secondary cementing operations may also be performed. One example of a secondary cementing operation is squeeze cementing whereby a cement slurry is employed to plug and seal off undesirable flow passages in the cement sheath and/or the casing.
One problem commonly encountered during the placement of a cement slurry in a wellbore is unwanted gas migration from the subterranean formation into and through the cement slurry. Gas migration is caused by the behavior of the cement slurry during a transition phase in which the cement slurry changes from a true hydraulic fluid to a highly viscous mass showing some solid characteristics. When first placed in the annulus, the cement slurry acts as a true liquid and thus transmits hydrostatic pressure. However, during the transition phase, certain events occur that cause the cement slurry to lose its ability to transmit hydrostatic pressure. One of those events is the loss of fluid from the slurry to the subterranean zone. Another event is the development of static gel strength, i.e., stiffness, in the slurry. As a result, the pressure exerted on the formation by the cement slurry falls below the pressure of the gas in the formation such that the gas begins to migrate into and through the cement slurry. Eventually the gel strength of the cement slurry increases to a value sufficient to resist the pressure exerted by the gas in the formation against the slurry.
The flow channels formed in the cement during such gas migration undesirably remain in the cement once it has set. Those flow channels can permit further migration of fluid through the cement. Thus, the cement residing in the annulus may be ineffective at maintaining the isolation of the subterranean formation. As such, gas may undesirably leak to the surface or to other subterranean formations. An expensive remedial squeeze cementing operation may be required to prevent such leakage. However, the gas leakage may further cause high volume blow-outs shortly after cement replacement and before the cement has initially set.
In an effort to suppress gas migration, cement slurries have been designed that include metal particles such as an aluminum powder for generating a stabilized, dispersed gas. The gas is often generated in situ in a cement slurry by reacting the metal particles with an alkaline solution, e.g., the cement slurry, and/or water to yield hydrogen. A sufficient amount of gas is formed in the cement slurry to prevent the migration of gas into or through the slurry before it has sufficiently gelled to resist such migration.
The metal particles contained in the cement slurry are usually encapsulated with an inhibitor for delaying the hydrogen-generating reaction until a desired time such as after the slurry has been placed in its desired location in the wellbore, e.g., the annulus. Ideally, the inhibitor effectively inhibits the particles from interacting and reacting with oxygen, water vapor, and the cement slurry until gas generation is desired. Examples of chemical reaction inhibitors commonly used to encapsulate the reactant metal particles, particularly aluminum powder, are fatty acids of sorbitan, glycerol, and/or pentaerythritol such as sorbitan monooleate. Additional information relating to the use of metal particles to generate gas in cement slurries and/or inhibitors to retard the generation of the gas may be found in U.S. Pat. Nos. 5,718,292, 4,565,578, 4,450,010, 4,367,093, and 4,340,427, and in U.S. Patent Application Publication No. 2004/0221990 A1, each of which is incorporated herein by reference.
Unfortunately, metal particles coated with such inhibitors suffer from the drawback of undergoing severe sintering when they are not flowable such as when they are being stored. As used herein, “sintering” refers to the agglomeration of metal powders at temperatures below the melting point. Such sintering may be facilitated by the non-uniformity of the inhibitor coating, mechanical vibration of the particles such as when they are being transported, the compaction of the particles in a container, and/or the exposure of the particles to relatively high temperatures, air, oxygen, and/or moisture. As a result of such sintering, the metal particles are neither free flowing as before nor properly encapsulated with the inhibitor, making the particles extremely reactive. They may react with water vapor and release the hydrogen prematurely, or they may bond with oxygen to form metal oxides, precluding them from later forming hydrogen gas. The duration for which the particles can be stored without undergoing any changes in their physical (e.g., free flowing nature) or chemical properties, which is known as the shelf life of the particles, thus is often shorter than desired. A need therefore exists to develop an improved way of delaying the reaction of the metal particles and thereby improve the shelf life of such particles.
Methods of Improving the Shelf Life of a Cement Composition Comprising a Coated Gas-Generating Material
Some teachings and advantages found in the present application are summarized briefly below. However, note that the present application may disclose multiple embodiments, and not all of the statements in this section necessarily relate to all of those embodiments. Moreover, none of these statements limit the claims in any way.
According to various embodiments, methods of increasing a shelf life of a gas-generating material comprise: including a C 8 -C 18 hydrocarbon in a mixture used to coat the gas-generating material. In an embodiment, the C 8 -C 18 hydrocarbon primarily comprises an aliphatic hydrocarbon. This gas-generating material may be used in a cement composition to generate gas therein after the composition has been placed in a wellbore. The coating surrounding the gas-generating material serves to delay the reaction for producing the gas until desired. The gas may serve to inhibit gas migration from an adjacent subterranean formation into and through the cement composition before it sets into a hard mass.
Coating the gas-generating material with the mixture can ensure that it can be stored for a relatively long period of time (e.g., up to 1 year or longer) without being concerned that it might experience sintering and thus loose its free flowing nature and react prematurely. Without being limited by theory, it is believed that the C 8 -C 18 hydrocarbon acts as a thinner to dilute the fatty acid ester of sorbitan, glycerol, or pentaerythritol, thus providing for a more uniform coating of the gas-generating material with the mixture. The C 8 -C 18 hydrocarbon is hydrophobic in nature. Thus, in some embodiments, it may enhance the ability of the coating to protect the gas-generating material from contacting water while it is being stored. However, it is understood that during the coating procedure, the whole mixture may reach temperatures higher than the ambient temperature due to mechanical reasons. Consequently, a portion of the C 8 -C 18 hydrocarbon may evaporate depending upon its vaporization temperature (usually increases with increasing molecular weight i.e., from C 8 to C 18 ) and the temperature it reaches during coating, leaving the relatively uniform coating of the fatty acid ester of sorbitan, glycerol, or pentaerythritol to protect the gas-generating material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a side plan view of a drill rig and a wellbore for recovering oil or gas from a subterranean formation penetrated by the wellbore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Gas-generating additives for use in cement compositions include a gas-generating material at least partially encapsulated with a coating comprising one or more fatty acid esters of sorbitan, glycerol, and/or pentaerythritol and initially one or more C 8 -C 18 hydrocarbons for increasing the shelf life of the gas-generating material. The term “shelf life” is known in the art as meaning the duration for which the gas-generating material can be stored without undergoing any significant changes in either its physical (e.g., its free flowing nature) or chemical properties. In various embodiments, the shelf life may be increased to in a range of from greater than about 6 months to about 12 months. In other embodiments, the shelf life may be increased to 12 months or greater. Thus, the coated gas-generating material may be stored without losing its free flowing nature and its ability to generate gas until it is time to prepare the cement compositions. It is understood that during the coating procedure, the temperature of the whole coating mixture may exceed the ambient temperature due to mechanical reasons, e.g., grinding of the gas-generating particles. As a result, at least a portion of the C 8 -C 18 hydrocarbon may evaporate due to its temperature reaching its vaporization temperature (usually increases with increasing molecular weight i.e., from C 8 to C 18 ) or higher during the coating procedure. Thus, only the relatively uniform coating of the fatty acid ester of sorbitan, glycerol, or pentaerythritol may remain to protect the gas-generating material.
The gas-generating additives may be included in cement compositions that also comprise cement and fluid. Various types of cements are known in the art and may be used in the cement compositions. The cement may be a hydraulic cement composed of calcium, aluminum, silicon, oxygen, and/or sulfur which sets and hardens by reaction with water. Examples of hydraulic cements include but are not limited to Portland cements, pozzolan cements, gypsum cements, high alumina content cements, silica cements, and high alkalinity cements. In some embodiments, the cement may be a class A, B, C, G, or H Portland cement. The cement compositions may also include a sufficient amount of fluid to form a pumpable cementitious slurry. Examples of suitable fluids include but are not limited to fresh water or salt water, e.g., an unsaturated aqueous salt solution or a saturated aqueous salt solution such as brine or seawater. In some embodiments, the water may be present in the cement compositions in an amount in the range of from about 33% to about 200% by weight of the cement (bwoc), alternatively from about 35% to about 60% bwoc.
The gas-generating material is desirably capable of generating gas such as hydrogen (H 2 ) via a chemical reaction. In various embodiments, the gas-generating material may comprise one or more metals that react with aqueous alkaline solutions or water to produce hydrogen. Examples of suitable metals include but are not limited to aluminum, calcium, zinc, magnesium, lithium, sodium, potassium, and combinations thereof. In some embodiments, the hydrogen-generating material is an aluminum powder. Examples of suitable commercial aluminum powders include SUPER CBL powder and GAS CHECK powder, both of which are available from Halliburton Energy Services, Inc. (HES). The amount of the gas-generating material included in the cement composition may be selected based on the amount of gas production required to prevent formation gas from migrating from a subterranean formation into the cement composition while it is being placed in a wellbore. The amount of gas-generating material required to yield a specified volume percent of gas in the cement composition increases with pressure. For example, about 0.6% bwoc of an aluminum powder coated with the mixture described above is required to produce about 5% of hydrogen gas by volume of the cement composition in the case of an American Petroleum Institute (API) casing schedule of 6,000 feet. Further, about 1.10% bwoc of the coated aluminum powder is required to produce the same volumetric amount of hydrogen gas in the case of an API casing schedule of 14,000 feet. These comparisons are based upon the use of a neat cement slurry having an initial compressibility of 28 (μv/v)/atm.
The coating employed to encapsulate the gas-generating material may serve as an inhibitor that delays the release of the gas in the cement composition until a desired time. Otherwise, the reaction of the gas-generating material to produce gas may occur rapidly, causing the gas to be released prior to the desired time, for example, prior to placing the cement composition in the annulus of a wellbore. Moreover, hydrogen gas is highly explosive and thus its generation at inappropriate times may be dangerous. The coating may initially be formed to include from about 3% to about 10%, or alternatively from about 4% to about 5%, of the one or more fatty acid esters of sorbitan, glycerol, and/or pentaerythritol, all percentages being by weight of the gas-generating material. It may further initially include from about 0.25% to about 5%, or alternatively from about 1% to about 2%, of the one or more C 8 -C 18 hydrocarbons, all percentages being by weight of the gas-generating material. Examples of suitable fatty acid esters of sorbitan, glycerol, and/or pentaerythritol include but are not limited to sorbitan monooleate (SMO), sorbitan monoricinoleate, sorbitan monotallate, sorbitan monoisostearate, sorbitan monostearate, sorbitan dioleate, sorbitan trioleate, glycerol monoricinoleate, glycerol monostearate, pentaerythritol monoricinoleate, and combinations thereof. Examples of suitable C 8 -C 18 hydrocarbons include but are not limited to isoparaffins such as IA-35 synthethic isoparaffin and EXPAR M synthetic isoparaffin, which are commercially available from EXPO Chemical Company, Inc. of Houston, Tex.
The inhibitor optionally may also include an anti-oxidant to make the gas-generating material less susceptible to reaction with oxygen (O 2 ). Otherwise, the atoms of the gas-generating material might bond with oxygen atoms to form an oxide, limiting the ability of the gas-generating material to later react with the cement composition and produce gas downhole. The anti-oxidant may be, for example, butylhydroxytoluene (BHT), butylated hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ). The amount of the anti-oxidant present in the mixture for coating the gas-generating material may range from about 0.01% to about 2.0% by weight of the gas-generating material, or alternatively from about 0.01% to about 1%.
As deemed appropriate by one skilled in the art, additional additives may be added to the cement compositions for improving or changing the properties of the cement compositions. Examples of suitable additives include but are not limited to fluid loss control agents, weighting agents, de-foamers, dispersing agents, set accelerators, and formation conditioning agents.
The gas-generating material may be prepared by first mixing together the components of the inhibitor, followed by coating the gas-generating material with the resulting liquid mixture. In some embodiments, the coating of the gas-generating material may be accomplished by mixing it with the liquid mixture such that it is thoroughly contacted and wetted with the mixture. In alternative embodiments, the liquid mixture may be sprayed onto the surface of the gas-generating material. As a result, the gas-generating material is entirely, or at least partially, coated with the mixture. The gas-generating material may be ground into a fine powder during this coating procedure. The coated gas-generating material may then be stored either off-site or on-site near where it is to later be used in a cement composition. The coating desirably prevents the gas-generating material from prematurely reacting while it is being stored and, if formed off-site, during its transport to the on-site location. When the time comes to form a cement composition, the coated gas-generating material may be dry blended with the cement, followed by mixing the resulting dry blend with water to form a pumpable cement slurry. Alternatively, the coated gas-generating material may be introduced to the mix water before it is combined with the cement to form a cement slurry.
FIG. 1 illustrates using a cement composition comprising the coated gas-generating material described herein. An oil rig 40 may be positioned near the surface of the earth 42 for later recovering oil from a subterranean formation (not shown). A wellbore 44 may be drilled in the earth 42 such that it penetrates the subterranean formation. A pipe 52 , e.g., a casing, may extend down through wellbore 44 for delivering fluid to and/or from the wellbore. In a primary cementing process, the cement composition may be pumped down through pipe 52 and up through the annulus of wellbore 44 as indicated by arrows 46 using one or more pumps 54 . The cement composition may be allowed to set within the annulus, thereby sealing wellbore 44 . Any secondary cementing operations known in the art may also be performed using the cement composition. For example, a squeeze cementing technique may be employed to plug permeable areas or voids in the cement sheath or the pipe 52 .
The inhibitor employed to coat the gas-generating material desirably delays the reaction by which the gas-generating material produces gas, e.g., hydrogen, until the cement composition has been placed in its desired location in the wellbore and before or during a transition time of the cement composition. The placement time of the cement slurry may vary with well depth, hole size, casing size, and placement rate. It is typically in the range of from about 15 minutes to about 300 minutes. In embodiments in which the gas-generating material is aluminum such as the finely ground SUPER CBL aluminum powder, the reaction by which it produces hydrogen relies on the alkalinity of the cement composition and generally proceeds according to the following reaction:
2Al (s) +2OH − (aq) +6H 2 O→2Al(OH) 4 − (aq) +3H 2(g)
The particular reaction rate delay that results from coating the gas-generating material with the inhibitor depends on various factors, including the properties of the gas-generating material, the downhole conditions, the composition of the cement composition, and so forth. The reaction rate increases with increasing temperature and decreases with increasing pressure. The reaction may be delayed for an initial time period of from about 15 minutes to about 90 minutes during which the coating either slowly dissolves or the reactants undergo diffusion through the coating. The reaction rate then slowly increases to a peak reaction rate for a period of from about 30 minutes to about 300 minutes.
EXAMPLES
The invention having been generally described, the following examples are given as particular embodiments of the invention and to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification or the claims to follow in any manner.
Example 1
A test sample was prepared by coating SUPER CBL aluminum powder with 4% SMO and 2% IA-35 isoparaffin by weight of the SUPER CBL aluminum powder. Its shelf life was accelerated to allow this example to be carried out in a short period of time. That is, the test sample was placed in a plastic cell, and that cell was then placed in a vibrating water bath. Subsequently, air saturated with water vapor was passed through the cell while the bath was maintained at a higher temperature of 120° F. Therefore, the four ingredients, i.e., water vapor, oxygen, heat, and mechanical energy, required to accelerate the aging process were provided. The test sample survived 5 weeks without becoming very reactive and still remains usable.
Example 2
A test sample was prepared by coating SUPER CBL aluminum powder with 4% SMO and 0.5% BHT by weight of the SUPER CBL aluminum powder. It was then tested in the same manner as the test sample in Example 1. This test sample also survived 5 weeks without becoming very reactive and still remains usable.
Comparative Example 1
A conventional control sample was prepared by coating SUPER CBL aluminum powder with 4% SMO by weight of the SUPER CBL aluminum powder. It was then tested in the same manner as the test sample in Example 1. This test sample became too reactive to remain usable after 3 weeks. The typical shelf life of a conventional SUPER CBL aluminum powder coated with 4% SMO is about 6 months when its aging process is not accelerated.
Based on the foregoing examples, using IA-35 isoparaffin or a BHT anti-oxidant in combination with the SMO forms a better coating for the aluminum powder by improving the shelf life of that powder. Therefore, an aluminum powder coated in this manner may serve as a very good gas-generating material in a cement composition.
In various embodiments, methods of cementing in a wellbore comprise: coating a gas-generating material with a mixture comprising a fatty acid ester of sorbitan, glycerol, or pentaerythritol and a C 8 -C 18 hydrocarbon for increasing a shelf life of the gas-generating material; preparing a cement composition comprising the gas-generating material; introducing the cement composition into a wellbore; and allowing the cement composition to set.
In additional embodiments, methods of cementing in a wellbore comprise: coating a gas-generating material with a mixture comprising a fatty acid ester of sorbitan, glycerol, or pentaerythritol and a C 8 -C 18 hydrocarbon, thereby delaying the generation of a gas; preparing a cement composition by combining a cement, a fluid for making the cement composition pumpable, and the gas-generating material; displacing the cement composition into the wellbore; allowing the gas-generating material to generate the gas within the cement composition; and allowing the cement composition to set.
According to various embodiments, gas-generating additives for use in a cement composition comprise: a gas-generating material at least partially encapsulated by a coating comprising a fatty acid ester of sorbitan, glycerol, or pentaerythritol and having a shelf life of about 12 months or greater. In more embodiments, cement compositions comprise: a gas-generating material at least partially coated with a mixture comprising a fatty acid ester of sorbitan, glycerol, or pentaerythritol and a C 8 -C 18 hydrocarbon for increasing a shelf life of the gas-generating material. In yet more embodiments, cement compositions comprise: a cement; a fluid for making the cement composition pumpable; a hydrogen-generating material at least partially coated with a mixture for delaying a hydrogen-generating reaction, the mixture comprising sorbitan monooleate and an isoparaffin.
MODIFICATIONS AND VARIATIONS
The foregoing methods of cementing a wellbore may be applied to various types of wells, including injection wells, single production wells such as oil and gas wells, and multiple completion wells.
While preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention.
Accordingly, the scope of protection is not limited by the description set out above but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are a further description and are an addition to the preferred embodiments of the present invention. The discussion of a reference herein is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent that they provide exemplary, procedural, or other details supplementary to those set forth herein. | According to various embodiments, methods of increasing a shelf life of a gas-generating material comprise: including a C 8 -C 18 hydrocarbon in a mixture used to coat the gas-generating material. This gas-generating material may be used in a cement composition to generate gas therein after the composition has been placed in a wellbore. The coating surrounding the gas-generating material serves to delay the reaction for producing the gas until desired. The gas may serve to inhibit gas migration from an adjacent subterranean formation into and through the cement composition before it sets into a hard mass. Coating the gas-generating material with the mixture may ensure that it can be stored for a relatively long period of time (e.g., up to 1 year or longer) without being concerned that it might experience sintering and thus react prematurely. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to pressure sensitive adhesives, and more particularly to adhesives used in the graphics industry.
Pressure sensitive adhesives for the graphics industry are usually coated on one side or two sides of a substrate. The substrate can be a thin film (e.g., "tape") coated on either one or both sides, or a board (e.g., paper, plastic, or foam) coated on one side to be used for mounting. One might adhere an art poster to a board prior to framing or use a double adhesive sided tape to make a display of pictures or articles where the two sided tape is hidden between the two objects being held together. Alternatively, the tape can already be adhered on one of the substrate, with a release liner, so the release liner can be peeled away to expose a tacky pressure sensitive adhesive. A two-sided tape can be provided in a small one-half inch by three yard roll, on a dispenser, for the user to roll off small strips, place them on the back of an item, then adhere the item to another substrate. The item could be pressure sensitive wallpaper or vinyl letters for a boat name or identification number.
Both skilled as well as unskilled users of conventional pressure sensitive adhesives have been victim to sticking down a misaligned item, due to prematurely letting go of it. Even after correct placement, the user must "smooth out" the item. The further skill of achieving an acceptable bubble-free and wrinkle-free lamination is very difficult to perfect, especially for the novice. For this very reason, a product that is non-tacky until heated was developed for a number of applications. This heat activated adhesive is used extensively in the framing industry (dry mount adhesive). A significant source and amount of heat (a heat press) is used to press and heat the substrate until the adhesive melts 160 F-250 F and bonds the substrate to the item.
Heat activated adhesives have a number of drawbacks. All substrates will curl to some extent when heat and pressure are applied. The danger of burns is ever-present. The cost of electricity and fairly long production time to heat up and cool down bonded substrate are clear disadvantages. Once an adhesive becomes a liquid or soft enough to flow and effect a bond, there is a risk it will change the visual appearance of a paper or poster due to melt-through or paper/plastic transmission variables. Many applications simply are not practical for heat activated adhesives. Universal adhesion to, e.g., plastic, paper, metal, and fabric with a single adhesive is very difficult to achieve. Due to this limitation the industry has responded with many heat activated products based on polyester, polyolefins, nylons, and polyurethane, etc. Each such adhesive has its unique application temperature, melt parameters, and substrate suitability.
Certainly conventional pressure sensitive adhesive have a convenience advantage over heat activated adhesives, but the previously stated problems with such pressure sensitive adhesives, limits their appeal to users having a high level of skill in application, or a high frustration tolerance.
Some industries have developed specific products to deal with such pressure sensitive application problems. The sign industry uses large quantities of pressure sensitive vinyl, and markets an auxiliary product called "application fluid". This is essentially a slippery fluid wiped or sprayed on the tacky adhesive side of the vinyl so one can temporarily make the adhesive non-tacky for ease of placement and creation of fewer air bubbles. This fluid is a messy solution for use on non-porous substrate. Other companies have addressed the drawbacks of pressure sensitive adhesives by cutting the tack and/or peel values of the adhesives. This can be accomplished in a number of ways, such as by including additives like waxes, lubricants, and silicone. Another approach is to include fillers and particulates (e.g., microspheres) in the adhesive coating to roughen up the surface of the adhesive, thereby cutting down on initial surface contact area. It is easily appreciated that most pressure sensitive adhesive applications call for permanent, reliable bonding. The techniques for achieving less tack are unreliable and the effectiveness of the coating is unpredictable batch to batch, due to variations in coating parameters, such as oven temperature, humidity, raw materials, etc. Above all, it must be noted that in general the lower the initial tack, the lower the chances for high permanent bonding.
SUMMARY OF THE INVENTION
It is an object of the present invention to effect permanent and reliable pressure sensitive adhesive bonding of one substrate to another using a novel pressure activated adhesive system which is initially non-tacky.
It is another object of the invention to provide a method of producing a pressure activated adhesive system which is initially non-tacky and which can ultimately be used on graphics sheet material, as well as in a tape or on a framing board.
According to the invention, an adhesive coating or layer has a differential height barrier structure deposited on the surface of one or both sides. Consequently, a highly aggressive adhesive formulation can be temporarily neutralized so as not to resist sliding of an item being positioned on the surface, until pressure is deliberately applied. Conversely, the adhesive system can be carried by decorative sheet material for easy application of the sheet material to cover a wall or floor, whereby the sheet can be slid into exact position without "sticking", before permanent adhesion.
The present invention may be implemented by forming an array of discrete surface barrier structures which cover 10-30% of the active surface area of the adhesive. The barrier is preferably formed by an array of hard, discrete structures distributed on the adhesive surface and projecting therefrom by about 0.00025-0.0005 inch. The present invention relies on the substrate to be bonded (the item without adhesive) never coming into contact with the actual adhesive until pressure is applied either manually, by vacuum, or by mechanical press. When pressure is applied, the barrier pattern no longer keeps the adhesive from contacting the item. The adhesive wets out and bonds in seconds (an unexpectedly short period of time). Air entrapment and bubbles are insignificant due to the escape of air around and between the barrier pattern. This achieves smooth adhesion.
The present invention is different from the "repositionable" or "controlled-tack" products which are commercially available. The present invention allows for sliding the item to be mounted into position as if no adhesive were present on the mounting substrate. In the embodiment wherein a decorative sheet carries the adhesive system of the invention, the sheet is the item to be positioned without tackiness. After the item has been correctly positioned, it is secured by pressing down with a finger to tack the item in place. Permanent full-surface bonding can be effected by pressure alone.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will be more evident upon reading the following description of the preferred embodiment with reference to the accompanying drawings, in which:
FIG. 1 is a schematic view partly in section, of a mounting substrate which carries an adhesive system by which an item such as a photograph can be secured to the substrate;
FIG. 2 is a schematic view similar to FIG. 1, after the release sheet has been removed from the adhesive system, thereby exposing the adhesive layer for receiving the photograph;
FIG. 3 is an enlarged view of the adhesive layer shown in FIG. 2, with the discrete barrier structure as shown on the surface according to the preferred embodiment of the invention;
FIG. 4 is an enlarged view of the release sheet portion of the adhesive system of FIG. 1, before the discrete barrier structures have been transferred to the adhesive layer;
FIG. 5 is an enlarged view of the completed graphic system, showing the nature of the bonded interface between the photograph and the adhesive layer; and
FIG. 6 is a schematic view, partly in section, of a decorative sheet material which carries an adhesive system by which the sheet material can be secured to a floor or wall.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-5 illustrate one embodiment of the present invention, whereby a graphic item such as a photograph 10 or the like, can be bonded to a framing board or similar mounting substrate 12, by use of a pressure activated adhesive system 14. In the illustrated embodiment, the board 12 has a relatively large surface area onto which the smaller photograph 10 is to be precisely aligned and secured. In this embodiment, the adhesive system 14 has first been bonded to the substrate 12, and the adhesive system has the same or preferably smaller area as the photograph 10.
The adhesive system of this embodiment consists essentially of a release liner in the form of a transfer sheet 16 which serves as a carrier for the adhesive layer 18. In a commercial context, the user would typically have a roll of tape composed of the two layer adhesive system 14. A suitable length of tape would be unrolled, cut, and secured on the substrate 12, with tacky adhesive side down. Alternatively, one side of a double sided non-tacky tape according to the invention could be exposed by removing its release liner, positioning the tape on the substrate and then securing it against substrate 12 to arrive at the configuration shown in FIG. 1.
In other embodiments, the substrate 12 could be purchased with the adhesive system 14 already in place thereon, covering either all or a pre-defined portion of the entire area of the substrate 12. In this embodiment, the adhesive system 14 would have been laminated to substrate 12.
As shown in FIG. 2, the user peels away the release sheet or layer 16 on the side of the adhesive liner opposite substrate 12, to expose the adhesive surface 20 of adhesive layer 18. Of course, the adhesion between layer 18 and substrate 12 is significantly greater than the adhesion between surface 20 of layer 18 and surface 22 of the release sheet 16. Preferably, release sheet 16 is a polyester or other dimensionally stable film having a preferred thickness in the range of about 2.0 to 5.0 mils. A more important characteristic, however, is that upon removal of the release sheet 16, the exposed adhesive surface 20 of the adhesive layer 18, exhibits certain key features as shown in FIG. 3.
FIG. 3 shows the exposed surface 20 as carrying a multiplicity of discrete barrier structures 24, which are spaced apart for reasons to be discussed more fully below. Preferably, the structures are in the form of discrete, minute units, which resemble the ink dot pattern in newspaper or other ink printed photographs. Each dot 24 has an exposed upper surface or top end 26 which is free of any tackiness, i.e., the surface 20 has no adhesive thereon. The lower surface or bottom end 28 of each dot 24, can be on or slightly embedded within the substantially flat exposed adhesive surface 30. Under either condition, each dot 24 projects from the nominal adhesive surface 30, by a distance "h" in the range of about 0.00025-0.00050 inch (0.25 to 0.50 mils). Therefore, the length of each dot in the direction "h", is at least about 0.00025 inch.
The barrier structure such as dots 24 preferably have a flat upper surface 26, rather than a sharp or highly curved surface. The barrier structure should occupy 10-30%, preferably about 20%, of the total area of surface 20 of the adhesive layer 18. This can be achieved with the preferred dot structure, by using screen printing or analogous techniques in the range of about 40-60 lines per inch.
One technique for producing the configuration of dots 24 as shown in FIG. 3, can be implemented by first printing, nipping, or otherwise depositing the dots onto the underside 22 of the carrier sheet 16 before the sheet 16 is laminated as by nip rolls, with adhesive material constituting layer 18. Layer 18 could be carried by a tape release liner (not shown), or it could have been previously applied as by coating on the framing board 12 (or graphics sheet as shown in FIG. 6). Preferably, the adhesive 18 is not coated onto the dots. The carrier sheet 16 can be printed for example, by rotary screen with an ink having high solids content, to produce the configuration shown in FIG. 4. Because the release liner or sheet 16 is of a conventional type which has release properties, the top surface 26 of each dot 24 is only tenuously adhered to sheet 16. In contrast, the bottom surface 28 of each dot will adhere aggressively to the adhesive material at 30 on the layer 18, when the layers 16 and 18 are laminated or otherwise formed together to produce, e.g., a tape. Thus, as may be appreciated with reference to FIGS. 1-3, upon peeling away of liner 16 from adhesive layer 18, the dots 24 transfer from liner 16 as shown in FIG. 4, to layer 18 as shown in FIG. 3.
When the active surface 20 adhesive layer 18 is exposed as shown in FIGS. 2 and 3, the photograph 10 can be placed on the adhesive layer 18, whereby the lower surface 32 of item 10 rests on the barrier structure 24. In particular, the underside 32 of item 10 can slide on the upper surfaces 26 of the barrier structure, to achieve "non-tack" repositioning and alignment of the item 10 relative to the substrate 12. It should be appreciated that, typically, the user can secure the adhesive system 14 to the substrate 12 without exercising great care, because the area of the adhesive system 14 should be smaller than that of the item 10. Therefore, any misalignment of the adhesive system will be covered and hidden by the item 10. Whereas conventionally, significant problems or inconveniences have burdened the user in trying to achieve precise alignment of the item 10 relative to substrate 12, the freedom afforded by the present invention to slide and reposition the item while the item rests on the adhesive layer 18, represents a major advance in the state of the art.
Once the user has properly aligned the item on the adhesive layer 18, the user presses on the item with, for example, casual finger pressure, thereby tacking the item in place. Thereafter, substantially all of the surface 32 of item 10 is bonded to surface 30 of adhesive layer 18 by using a roller, squeegee, vacuum press, or other application of pressure over the entire viewable surface 34 of item 10. The resulting bonded interface is shown in FIG. 5. The application of bonding pressure may cause the barrier structure to recede somewhat into the adhesive layer 18, while at the same time the adhesive material 30' adjacent the barrier structure 24, wets out to provide attachment to the portion 32' of the item 10, thereby reducing substantially the gap 36 which was perhaps created during the initial tacking after satisfactory alignment of the item.
The projecting barrier structure not only permits sliding of the item 10 relative to the adhesive layer 18, but also permits the escape of air from between item 10 and surface 20, as the user draws a squeegee or similar edge tool across surface 34 of item 10 to effectuate the uniform and permanent bond between surface 32 and surface 30. Furthermore, the pressure applied by the edge tool or the like, is imposed on relatively flat surfaces 26 of the barrier structure, thereby avoiding localized grainy patterns often accompanying the use of semi-tacky adhesive systems containing, for example, microspheres. Moreover, most known adhesive systems of this type have the microspheres distributed either uniformly or preferentially toward the surface of the adhesive layer, but the microspheres are usually submerged and therefore covered by adhesive material. Even if such microspheres project from the nominal surface level of the adhesive layer, thereby reducing the area of the item which contacts adhesive material in the layer, some tackiness is still present and prevents the sliding advantage achievable with the present invention. Thus, the present invention achieves the combination of sliding alignment, exhaust of trapped air, and avoidance of gritty surface irregularities. This combination is not possible with any currently known pressure sensitive adhesive systems in the field of graphics.
Of course, the user of the inventive adhesive system expects that the item 10 will remain securely bonded to the substrate 20 indefinitely, producing a graphic system 38 observable as a permanent mounting of the item 10 on the mounting substrate 12. Another advantage of the present invention, is that an aggressive adhesive material can be utilized while still achieving the sliding alignment capability. Preferably, a conventional pressure sensitive acrylic adhesive is used, at a thickness in the range of 1.0-2.0 mils, preferably about 1.5 mils. Despite the initial isolation of the item 10 from the adhesive surface 30 due to coverage by the barrier structure 24, the effect of the barrier structure receding into the adhesive and/or the adhesive moving outwardly along the sides of the barrier structure after full surface pressure has been applied, as represented at 30' in FIG. 5, assures that enough contact is maintained at the interface between items 10 and layer 18, to achieve long-lasting, secure bonding.
Based on the foregoing description, one of ordinary skill in the graphics field, can optimize the inventive pressure activated adhesive system according to the particular end use. For example, when a relatively thick item 10 is to be mounted, an important objective is achieving permanent bonding despite the significant weight of the item. On the other hand, if one intends to mount a thin metallic foil to a substrate, an important objective might be avoidance of air bubbles and any grainy or gritty surface irregularities due to the presence of the underlying barrier structures. Variables which are available to optimize the invention include the configuration of the barrier structure, the extent of surface area occupied by the barrier structure, the projection height of the barrier structure from the nominal surface of the adhesive layer, and the composition and color of the barrier structure. If the density and/or height "h" of the dots are too large, the permanent bond effectiveness will be undermined. If the density and/or height are too small, the "non-tacky" sliding for alignment will be undermined.
As a particular example, a dot pattern printed at 55 lines per inch according to conventional standards of photographic rendition, would result in a center-to-center distance between adjacent dots, of about 0.020 inch, and a distance between edges of adjacent dots, of about 0.012 inch. The dots would cover about 20-30 percent of the total surface area.
Another optimization regarding the composition of the barrier structure, includes the use of a release ink, such as silicone ink, if one wanted to minimize the possibility that the adhesive material at 30' might "crawl-up" the sides of the barrier structure and thereby reach the upper surface 26 on which no adhesive should be present. Another advantage of the present invention, is that only the barrier material, i.e., the dots, project above the nominal surface of the adhesive layer. This also avoids the possibility that (for example due to low surface tension) adhesive material immediately beneath the dots might extrude around the dots during handling and thereby contaminate the upper surface of the dots.
The barrier structure can include materials chosen primarily for convenience in distribution onto the adhesive surface. In the embodiment illustrated in FIGS. 1, 2, and 3, the dots 24 were printed onto the release sheet or liner 16, and thereafter transferred onto the pressure sensitive layer 18. Alternatively, the mounting board 12 or other substrate could have been first coated or laminated with an adhesive and thereafter the release liner, with printed barrier structure down, placed thereon. The release liner would cover the substrate and the adhesive coating, until the user was ready to mount an item thereon, at which time the user would peel away the release liner.
As is known with conventional pressure sensitive adhesive systems, the present invention can be implemented in the context of either single sided or double sided tape. The invention could alternatively be in the form of a laminate sold in rolls for covering a poster board or other mounting board.
As shown in FIG. 6, a decorative sheet material 100 (or mounting board) could be coated with adhesive 102 and a liner 104 having the barrier structure 106, nip rolled against the adhesive coating on the back side 108 of the decorative sheet or board. One can readily appreciate that the configuration shown in FIG. 6 could be applied to a wall or floor 116, after the release liner 104 is removed. In this embodiment, the decorative sheet has a back side 108 laminated to the side 110 of the adhesive layer 102 which is opposite the side 112 of the adhesive layer 102 which carries the dots 106. The other side 114 of the decorative sheet, exhibits or is covered by, a graphic pattern or design.
Although the barrier structure has been described in the preferred form of discrete, spaced-apart structures such as dots, other formations such as chevrons or herringbones, if properly spaced apart, can also be utilized for some applications. | An adhesive coating or layer has a differential height barrier structure deposited on the surface of one or both sides. Consequently, a highly aggressive adhesive formulation can be temporarily neutralized so as not to resist sliding of an item being positioned on the surface, until pressure is deliberately applied. Conversely, the adhesive system can be carried by decorative sheet material for easy application of the sheet material to cover a wall or floor, whereby the sheet can be slid into exact position without "sticking", before permanent adhesion. The present invention may be implemented by forming an array of discrete surface barrier structures which cover 10-30% of the active surface area of the adhesive. The barrier is preferably formed by an array of minute units of hard material or other discrete structures distributed on the adhesive surface and projecting therefrom by about 0.00025-0.0005 inch. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a card reader and to a card reader/writer The invention has application, for example, to a card reader for use in a transaction terminal such as an automated teller machine (ATM).
There are presently two types of card that can be used in an ATM: a magnetic stripe card; and an integrated circuit (IC) card. IC cards carry an IC chip which can be configured to provide a variety of functions. IC cards are commonly referred to as "smart cards", and are well known to persons skilled in the art.
Both types of card can store a variety of encoded user information, such as, account information, or user identification information in the form of a so called PIN (Personal Identification Number) which is required by an ATM before the ATM will grant a user access to the services provided by the ATM.
Many such cards are multipurpose cards which function not only as a user identification card for use with ATMs, but also as a cheque guarantee card, and/or as a debit/credit card which enables money to be debited from a user's bank account.
Whatever type of card is used, fraudulent or unauthorized use of such cards is a common problem, with significant consequences to the financial institutions issuing the cards.
It is known, for example, to insert a card shaped device into a card reader, which causes a card subsequently inserted into the card reader to become jammed when the reader attempts to return the card to the user. Both the card shaped device and the jammed card can then be removed from the card reader by an unauthorized person, utilizing a specially designed tool. The card can then be used fraudulently in an ATM if the PIN associated with the illegally removed card is known.
Even if the PIN is not known it may still be possible to make use of a multipurpose card either as a cheque guarantee card or as a debit/credit card, as only the user's signature is required in order to authorize a transaction with such cards.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a card reader, which reduces the risk of magnetic stripe cards or smart cards being fraudulently used.
According to the present invention, there is provided a card reader including detection means for determining a predetermined irregular mode of operation, characterized by card invalidation means operable to render a card permanently non-usable in response to the detection of said predetermined irregular mode of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic plan view of a magnetic stripe card;
FIG. 2A is a schematic side view of a first embodiment of a card reader in accordance with the present invention, with a card inserted therein, including a card invalidation means comprising a deformation plate;
FIG. 2B is a schematic plan view of the card reader of FIG. 2A;
FIG. 3 is a block diagram of parts of a card reader in accordance with the present invention;
FIG. 4A is an enlarged perspective view of the deformation plate of FIG. 2;
FIG. 4B is an enlarged perspective view of a cutting blade which can be utilized as the invalidation means in the reader of FIG. 2 instead of the deformation plate;
FIG. 5A is a schematic side view of a further embodiment of a card reader in accordance with the invention with a card inserted therein, wherein the invalidation means comprises hot air deformation means;
FIG. 5B is a schematic plan view of the card reader of FIG. 5A; and
FIG. 5C is a block diagram of the card reader of FIGS. 5A and 5B;
DETAILED DESCRIPTION
FIG. 1 illustrates a magnetic stripe card 2 carrying a magnetic stripe 3 running along the length of the reference edge 4 of the card 2. Substantially parallel to the magnetic stripe 3 is a stripe 5 designed to receive the written signature of the authorized user of the card.
Most cards are substantially rectangular in shape being approximately 85 mm long and 55 mm wide.
FIGS. 2A and 2B illustrate a first embodiment of a card reader 10 in accordance with the invention. The card reader 10 is designed to read magnetic stripe cards, such as the card illustrated in FIG. 1. The invention is also applicable to card readers which read smart cards; however, for simplicity the invention will be described herein only in terms of a magnetic stripe card reader.
The card reader 10 is designed to be incorporated in a host device, for example an ATM, and connected to a central processor unit (CPU) 100 (FIG. 3) in the host device via is connection means 101, thus enabling communication between the reader and the CPU 100 in the host device.
The reader 10 includes an input slot 11 dimensioned so as to receive the card 2. When not in use, access to the interior of the reader 10 is prohibited by means of a retractable shutter 12, the shutter 12 being retractable so as to enable the card 2 to be received into the interior of the reader 10.
The shutter 12 is located approximately 2 cms behind the slot 11. In the space between the slot 11 and the shutter 12 is located a pre-magnetic head 13, which detects whether or not a card 2 inserted into the slot 11 has a magnetic stripe 3, and sends a signal to that effect to a control means 50 in the reader 10. The position of the shutter 12 is controlled by a shutter actuator 51 (FIG. 3), which is operable under the control of the control means 50. If the pre-magnetic head 13 fails to detect a magnetic stripe 3, then the shutter 12 will not be retracted and access to the interior of the reader 10 will be denied.
The reader 10 incorporates card feed means 14 in the form of a first pair 15 and a second pair 16 of co-operating belt means which receive the card 2 adjacent the shutter 12 and convey the card 2 along a feed path 17. The belt means 16 grip the card 2 near the reference edge 4 and the belt means 15 grip the card 2 near the edge opposite thereto, to feed the card 4 along the feed path 17.
A magnetic stripe read-head 18 is located in the reader 10 so that the magnetic stripe 3 of a card 2 when transported along the feed path 17 passes above the read head 18, which can read the data therefrom. The read-head 18 detects the changes in magnetism along the length of the stripe 3 and provides an electrical signal in response thereto to the control means 50, the signals being representative of the data stored in the stripe 3, as is well known to persons skilled in the art.
In normal operation passage of the card 2 from the slot 11 throughout the reader 10 is monitored by the central processor 50 via an array of optical detectors 58, which are located along the feed path 17, from the shutter 12 to a location beyond the magnetic head 18 where the card 2 is stored prior to being returned to the user, during normal operation of the reader 10.
When the data has been read from the magnetic stripe 3, and an authorized user has completed a valid transaction with the host device, the reader 10 will attempt to return the card 2 to the slot 11 for removal by the user. As the card 2 is returned to the slot 11 the control means 50 causes the shutter 12 to be retracted and the card 2 to extend through the slot 11. The belt motor 52 is controlled to stop the card 2 from being expelled totally from the reader 10.
State of the art card readers operate largely as described above. A card reader in accordance with a first embodiment of the present invention is further provided with a movable deformation plate 21 located behind the shutter 12 (FIG. 2A), which can be actuated to invalidate a card 2 jammed in the reader 10 once the control means 50 determines that the card 2 has been jammed intentionally at the shutter 12, as will be described in detail below.
If the card 2 is jammed, say at the shutter 12, then the detector 58' adjacent the shutter 12 will detect the prolonged presence of the card 2 beneath the shutter 12, and will send a signal to this effect to the central processor 50.
The optical detectors 58 each comprise a light emitting diode (LED) 581 and an optical sensor 582 which is arranged to detect light emitted by the LED only if the light is reflected from the surface of a card 2 located in the feed path 17 above the detector 58.
If a card shaped device has been inserted into the space between the slot 11 and the shutter 12, the card 2 will become jammed beneath the shutter 12, with a portion of the card 2 extending beyond the shutter 12. Thus a person utilizing a specially designed tool could then remove the card shaped device and the card 2 from the reader, as discussed above.
A first embodiment of a reader 10 in accordance with the present invention is adapted to address this problem by providing the reader 10 with a card invalidation means in the form of a deformation plate 21, as mentioned above, which is actuable under the control of the control means 50 to damage a card 2 which is jammed in this manner.
The plate 21 is located, usually, in a retracted position above the feed path 17 in the card reader 10 behind the shutter 12 as shown in FIG. 2A. When a card 2 is jammed in the feed path 17, as discussed above, the presence of the card 2 at the shutter 12 is detected by the sensor 58' adjacent the shutter 12, whereupon the control means 50 sends a signal to the plate actuator means 53 which actuates the plate 21 which is urged down onto the card 2 with sufficient force to deform permanently the card 2, such that the card 2 will not be reusable.
The plate 21 (FIG. 4A) can be replaced by a blade 24 with a cutting edge 25 (FIG. 4B) such that when the blade 24 is urged down into contact with the card 2 the card is cut into two pieces. Both the plate 21 and the blade 24 are attached to movable means (not shown) in the reader 10 by screws (not shown) which are received through screw holes 32 located remote from the edge of the plate 21 or blade 24 which engages the card 2 when in use.
In a further embodiment of the present invention, illustrated in FIGS. 5A and 5B, and with reference to FIG. 5C, the card reader 10 is provided with a hot air nozzle 26 located just behind the shutter 12, in place of the invalidation means 21, 24. In all other respects the card reader 10 of FIGS. 5A and 5B operates in the same manner as the card readers of FIGS. 2A and 2B.
The hot air nozzle 26 is arranged to focus air forced through the nozzle. The nozzle 26 is connected to a flexible tube 28 which is in turn connected to a source of hot air in the form of a fan 30 and a heater 32 which heats the air produced by the fan 30. When a card 2 is jammed in the reader 10 at the shutter 12 as detected by the detector 58' (FIG. 5A), the control means 50 will cause a hot air actuation means 53 (FIG. 5C) to actuate the supply of hot air resulting in a controlled and focused blast of hot air being issued from the nozzle 26, thus distorting the plastic card 2. Such distortion of the card 2 renders the magnetic stripe 3 unreadable, and therefore the card 2 invalid.
The card reader 10 is also provided with both an air pressure sensor 56 (FIG. 5C) and an air temperature sensor 57, to ensure that only the required degree of deformation of the card 2 is produced. The air pressure sensor 56 will also detect any blockage of the air nozzle 26, and transmit a signal to this effect to the control means 50 which will then close down the reader 10 to ensure that the aforementioned fraudulent removal of a card 2 can not be attempted while the invalidation means may be ineffective.
The card reader 10 will not accept a subsequently tendered magnetic stripe card when any one of the detectors 58 detect that a card 2 is present in the feed path 17. Thus the invalidation means within the reader 10 can not be inadvertently actuated to damage a validly inserted card.
Such invalidated cards will not only be inoperative with ATMs. but will also not be usable as a cheque guarantee card, debit/credit card or any other sort of data card. | The invention relates to a card reader system (10) including a detector (58') for determining a predetermined irregular mode of operation of the reader system. The invention is characterized by a card invalidation device (21, 24, 26) operable to render a card (2) permanently non-usable in response to the detection of the predetermined irregular mode of operation. | 6 |
FIELD OF THE INVENTION
This invention relates to vanadium oxide crystalline compositions and more particularly to such compositions in which the vanadium oxide forms two dimensional layers between which are intercalated guest cations.
BACKGROUND OF THE INVENTION
There has been growing interest in vanadium compounds of various types for use as catalysts in a variety of chemical procedures. There also has been particular interest in vanadium oxides for use in electronic devices for heat sensing.
There has also been growing interest in layered structures, typically for use as hosts to support guest cations intercalated between the layers. In particular, layered inorganic oxides constitute a diverse class of materials most of which share the common structural feature of a cationic guest which lies between the anionic oxide layers. The largest number of examples known are layered materials composed largely of main group cations like clays, but solids with transition or post-transition elements like the layered double hydroxides and certain alkali metal titanates are also known. Layered oxides hosting both transition and main group cations, such as the Zr, V and Mo phosphates and phosphonates, have also been studied. While many of these solids are noted for their unique characteristic of allowing a wide variety of organic or inorganic chemistries to be performed in the interlamellar region, the closed shell diamagnetic layers serve mainly as an inert nanoscale scaffolding. In contrast to these diamagnetic layers, several lamellar vanadium oxide solids have been prepared by the intercalation of both alkali metal cations and conductive organic polymers between layers of V 2 O 5 . The present invention represents novel forms of such layered structures involving vanadium oxides.
SUMMARY OF THE INVENTION
The present invention provides compositions of the generic formula
(M.sub.1).sub.a (M.sub.2).sub.b (M.sub.3).sub.c [V.sub.x O.sub.y ]·zH.sub.2 O
in which the layered mixed-valence vanadium oxide forms host layers between which are intercalated either a) cationic transition or post-transition metal coordination complexes, b) monomeric ammonium or diammonium cations, or c) a mixture of alkali metal cations and monomeric ammonium or diammonium cations.
In the generic formula, M 1 is a metal-coordination complex [L n A] +w , where L is a bidentate amine ligand, A is a transition or post-transition metal, n is equal to 1, 2 or 3, and w is 1, 2, 3 or 4. When a is other than zero, b and c are zero. When b has a non-zero value, a is equal to zero and c may or may not have a non-zero value. When c has a value, M 3 is an alkali metal cation.
More complete descriptions of M 1 , M 2 and M 3 and particular examples of each will be provided in the more detailed description.
DETAILED DESCRIPTION OF THE INVENTION
As set forth above, the generic formula of compositions provided by the invention is
(M.sub.1).sub.a (M.sub.2).sub.b (M.sub.3).sub.c [V.sub.x O.sub.y ]zH.sub.2 O.
As mentioned above, M 1 is a metal coordination complex given by [L n A] +w , where the bidentate ligand L is a diamine of the form R 2 N(C m H 2m )NR 2 , or an aromatic diamine. R, as is familiar to the art, corresponds to C p H 2p+1 where 1≦m≦4, 0≦p≦4, the metal A is a transition or post-transition metal, preferably either Ni, Cu, or Zn, and w is an integer from 1 to 4.
The group in which the guest cations are solely interlayer transition or post-transition metal coordination complexes M 1 will be described as the first group of the generic formula.
The compositions of this first group of the generic formula, corresponding to b and c equal to zero in the generic formula, have been prepared, for example, in a single step by the reaction of a transition or post-transition element source, a bidentate amine and V 2 O 5 in water sealed in a 23-ml poly(tetrafluoroethylene) lined acid digestion bomb and heated in the 170°-200° C. range and are isolated as highly crystalline, typically thin black plates. Since no external reducing agent is employed, the amine presumably serves as the reducing agent. The materials, (L 2 M) y [VO x ] with L=bidentate amine, M═Cu, Ni or Zn, 0.16≦y≦0.33 and 2.33≦x≦2.83, share common structural features of a mixed valence V 4+ /V 5+ oxide layer as well as a six coordinate interlayer cation with four of the six co-ordination sites occupied by N atoms from two bidentate amine ligands and two sites from O atoms of the VO layer. The layers are built up in all cases from VO 5 square pyramids and VO 4 tetrahedra connected by edge and corner sharing interactions.
As an example of the preparation of a compound of the first group, there was heated together at a temperature of 170° C. for 44 hours and then at 200° C. for 112 hours a mixture of 0.312 gram of V 2 O 5 , 0.049 gram of ZnO, 10 milliliters of H 2 O and 0.325 gram of 2,2'-dipyridyl. After such treatment, there was filtered a mixture of brown chunks of [(bipy) 2 Zn] 2 [V 6 O 17 ] and black rod-shaped crystals of VO(VO 3 ) 6 [VO(bipy) 2 ], where (bipy)=2,2'-dipyridyl, and a small amount of unidentified green powder.
The structure of the compound [(bipy) 2 Zn] 2 [V 6 O 17 ], which is to be designated as Compound 1, consists of VO layers, which, when viewed parallel to [100], display a very pronounced sinusoidal ruffling with an amplitude of ca. 13 Å and a period of ca. 15 Å. These layers are composed solely of V 5+ O 4 tetrahedra, each of which has a terminal vanadyl (V═O) group and shares three corners with three neighboring VO 4 units. Within each VO layer there are very large, roughly circular rings, which alternately lie in planes approximately parallel to (011) and (011), defined by fourteen VO 4 tetrahedra with a transannular V-V distances near 13 Å. There are two Zn atoms per ring, on either side of the 1 site in the center of the ring, each bonded in a cis fashion to two oxygen atoms from two second nearest neighbor VO 4 groups on opposite sides of the ring. The two Zn atoms have bipy ligands that protrude above and below the mean plane of the V 14 ring and fill the troughs created from the ruffling of the layers with the organic ligands.
The use of ethylenediamine (en) as a bidentate ligand has allowed not only the isolation of several new one dimensional (1-D) Cu-en-VO materials but several layered solids as well. Two layered examples from the en system are the isotypic, mixed valence V 4+ /V 5+ vanadium oxides (en) 2 Zn[V 6 O 14 ] and (en) 2 Cu[V 6 O 14 ] to be designated Compounds 2 and 3, respectively. Compound 2 was prepared by mixing 0.192 (g) of V 2 O 5 , 0.042 (g) of ZnO, 10 (ml) of H 2 O and 0.2 (ml) of en and heating to 170° C. for 66 hours. Compound 3 was prepared by heating 170° C. for 65 hours a mixture of 0.17 (g) of copper chloride dihydrate, 0.181 (g) of V 2 O 5 , 0.28 (ml) of en and 8 (ml) of water. Both materials contain Cu or Zn in a distorted MO 2 N 4 octahedral environment coordinated to four N donor atoms, which lie approximately in a plane parallel to the VO layers, and two trans O atoms from two adjacent layers, coordinated via very long M--O interactions. While this nearly square planar coordination is not atypical for the Cu in Compound 3 (four N at ≈2.07 Å; two O at 2.53 Å), it is unusual for the Zn found in Compound 2 (two N at 2.12 Åand two at 2.07 Å; two O at 2.45 Å). The VO layers in Compounds 2 and 3 contain infinite zig-zag chains of edge-sharing V 4+ O 5 square pyramids running parallel to [010], with their terminal vanadyl groups oriented in pairs toward opposite sides of the layer, connected together by V 5+ O 4 tetrahedra giving a layer composition of [(V 5+ ) 2 (V 4+ ) 4 O 14 ] 2- according to valence sum calculations. Surprisingly, in spite of the fact that 2/3 of the V atoms are in the 4+ oxidation state (d 1 ), Compound 2 does not give an ESR signal and is nearly diamagnetic according to preliminary magnetization measurements that show that χ=M/H actually decreases in the range 150<T<300K. Compound 3 also appears to have layers with suppressed magnetic moments with μ eff (300K)≈2.2 BM (μ eff =[8χT] 1/2 ) only slightly greater than that expected (˜1.8 BM) for the Cu 2+ (S=1/2). Below room temperature, the moment slowly decreases and reaches the value expected for only the Cu 2+ by ˜70K and below this temperature χ -1 (T) is linear (unlike T>70K) with a θ near zero indicative of a paramagnet. The magnetic data for Compounds 2 and 3 imply that either the layers have already undergone an antiferromagnetic phase above room temperature or the spins are paired within states that are delocalized within the layers.
Changing the reaction conditions in the en/Cu 2+ V 2 O 5 system gives rise to other vanadium oxides with ligated Cu bound to the layers, such as [(en) 2 Cu] 2 [V 10 O 25 ], to be designated as Compound 4. This was prepared by heating at 170° C. for 42 hours a mixture of 0.51 (g) of copper chloride dihydrate, 0.181 (g) of V 2 O 5 , 0.45 (ml) of en and 8.0 (ml) of water. Like Compounds 2 and 3, Compound 4 has a nearly square planar (en) 2 M 2+ (M═Cu) cation bonded to two trans oxygen atoms from two adjacent layers which are formulated as [(V 5+ ) 6 (V 4+ ) 4 O 25 ] 4- according to valence sum calculations. The layers are built up from double strands of infinite corner sharing strings of edge-sharing trimeric VO 5 square pyramids, which run parallel to [001] and are connected together by VO 4 tetrahedra. The double strands are in turn bridged together by additional VO 4 tetrahedra to create a layer containing ordered voids with O--O diameters of 6 Å. Magnetization data shows that μ(300K)≈5.5 BM which is well below that expected for the six unpaired spins from 2 Cu 2+ and 4 V 4+ . The moment decreases nearly linearly over the entire range 20K<T<300K and reaches a value of ca. 2.8 BM near 10K which is the moment expected for two Cu 2+ (S=1/2) centers. Below ca. 15K, χ -1 (T) is linear with a θ near zero consistent with paramagnetism. Thus the magnetic behavior of Compound 4 resembles that of Compound 3 in that the layers have magnetic moments that slowly decrease over large temperature intervals, with no characteristic anomalies indicative of a phase transition, and appear essentially diamagnetic at very low temperatures.
As mentioned previously, another major group of the generic formula corresponding to a and c equal to zero in the generic formula, to be designated group 2, consists of organically templated mixed-valence vanadium oxides. In this second group, M 2 is an organic cation taken from the group consisting of R 4 N + , cyclic ammonium or polyammonium cations [Q 4-p N(C n H 2n ) p NQ 4-p ] +f where 1≦p≦3 and Q═R, C 6 H 5 or (C n H 2n ) N + R 3 with 1≦n≦4, and R is C m H 2m+1 or C 6 H 5 , where m=0≦m≦4 and f is the number of N atoms in the cyclic ammonium or polyammonium cation.
An example of this group 2 is (H 3 N(CH 2 ) 3 NH 3 )[V 4 O 10 ] to be designated Compound 5. Black plate-like crystals of Compound 5 were prepared from the hydrothermal reaction of 0.296 (g) of V 2 O 5 , 2.0 (ml) of 1.0M HCl, 0.2 (ml) of (dap) and 10 (ml) of H 2 O at 170° C. for 66 hours, where (dap) is 1,3-diaminopropane.
A single crystal X-ray diffraction study of Compound 5 revealed the novel vanadium oxide layers with propanediammonium dications occupying the interlamellar space. The layers are constructed from equal number of VO 4 tetrahedra and VO 5 square pyramids. While VO 4 tetrahedra are isolated from each other, the VO 5 square pyramids exist in pairs sharing one edge. Within a pair of square pyramids, the two apical oxygen atoms are oriented toward opposite sides of the plane of the layer. Each pair of the pyramids is linked to six VO 4 tetrahedra via corner-sharing, forming two dimensional layers. There are four independent V sites in this structure. While the atoms V(1) and V(4) have a distorted square pyramidal configuration, the atoms V(2) and V(3) are in a fairly regular tetrahedral coordination environment. The V-O bond distances of V(2)O 4 tetrahedron are in the range of 1.648 (4)-1.826 (4) Å, and bond angles in the range of 106.0(2)-113.2(2)°. The V(3)O 4 tetrahedron has bond distances in the range of 1.643 (5)-1.834 (4) Å, and bond angles in the range of 107.6(2)-111.3(2)°. The V(1)O 5 square pyramid has the shortest bond distance of 1.612 (4) Å formed with the vanadyl oxygen O(9), and the rest of the four V-O bond distances in the range of 1.912 (4)-1.967 (4) Å. The V(4)O 5 square pyramid has its vanadyl oxygen O(7) at a distance of 1.603 (4) Å, and the other four oxygen atoms at distances in the range of 1.924 (4)-1.974 (4) Å. While the square pyramidal vanadium has an oxidation state of +4, the tetrahedral vanadium is indicative of an oxidation state of +5. This assignment of oxidation state is consistent with the overall charge balance of the compound and confirmed by the valence sum calculation which gave a value of 4.1 for V(1) and V(4), and 4.8 for V(2) and V(3). There is an extensive hydrogen bonding network formed among the --NH 3 + groups of the propanediammonium cations and the terminal oxygen atoms (O(6), O(7), O(9), O(10)) from the oxide layers above and below. This extensive hydrogen bonding motif causes the organic components to be released only at elevated temperatures. Thermogravimetric analysis (TGA) at a heating rate of 10° C./min. under N 2 showed no weight loss until ca. 300° C. where the release of the organic component commences.
There has been a great deal of interest in vanadium bronzes M x V 2 O 5 , especially lithium vanadium bronzes Li x V 2 O 5 , because of their interesting electronic properties and potential applications in high energy batteries. The oxide layers in the structures of Compound 5 are similar to those in the structure of CsV 2 O 5 , described in Acta Cryst 1977, B33, 789 by K. Walterson et al, where the Cs + cations lie between the vanadium oxide layers. Compound 5 is believed to represent the first example of a new class of materials: organically based vanadium bronzes. One would expect that new vanadium oxide structure types can be made by introduction of organic templates of different sizes and charges. In fact, we have isolated several new layered vanadium oxides containing different organic cations including α- and β-(H 3 N(CH 2 ) 2 NH 3 )[V 4 O 10 ], (HN(C 2 H 4 ) 3 NH)[V 6 O 14 ]. H 2 O, α- and β-(H 2 N(C 2 H 4 ) 2 NH 2 )[V 4 O 10 ].
The third group corresponds to the situation where a=0, and both b and c have real values in the generic formula, so that both M 2 and M 3 are included.
An example of this group is Cs 0 .29 (DABCO) 0 .34 V 2 O 5 where DABCO is diprotonated 1,4-Diazabicyclo[2.2.2] octane N(C 2 H 4 ) 3 N. Samples of this were prepared by heating at 170° C. for 112 hours a mixture of 0.202 (g) CsVO 3 , 0.312 (g) H 2 O 3 PCH 3 , 10 (ml) H 2 O and 0.310 (g) DABCO. Other members of this group can be formed by including cations from the others of the alkali metal group, K + or Rb + .
The following are additional examples of the preparation of further representatives of the general class.
A mixture of 0.277 grams of V 2 O 5 , 0.049 gram of Cu0, 10 milliliters of water and 0.3 milliliter of H 2 N--CH 2 --CH 2 --CH 2 --NH 2 (dap) was heated at 170° C. and after 44 hours 0.118 grams of a solid was recovered after filtering, washing and air-drying. The solid was found to be of the following composition: (dap) 2 Cu[V 6 O 14 ], a member of the first group.
A mixture of 0.130 gram of V 2 O 3 , 0.197 gram of piperazine and 10 (ml) water was heated at 170° C. After 67 hours, and after filtering, water washing and air drying there was recovered 0.122 gram of a solid whose composition was found to be (H 2 N(CH 2 CH 2 ) 2 NH 2 )[V 4 O 9 ], a member of the second group.
A mixture of 0.218 gram of V 2 O 5 , 0.181 gram of piperazine and 10 milliliters of water was heated at 170° C. and after 115 hours there was recovered 0.152 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 2 N(CH 2 CH 2 ) 2 NH 2 )[V 4 O 10 ], a member of the second group.
A mixture of 0.173 gram of V 2 O 5 , 0.1 milliliter of en and 10 milliliters of water was heated at 170° C. and after 121 hours there was recovered 0.10 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 3 NCH 2 CH 2 NH 3 )[V 4 O 10 ], also a member of the second group.
A mixture of 0.257 gram of CsVO 3 , 0.186 gram of H 2 O 3 PCH 3 , 0.1 milliliter of en and 8 milliliters of water was heated at 170° C. and after 69 hours there was recovered 0.075 gram of a solid whose composition was found to be a mixture of α- and β-phase of (H 3 NCH 2 CH 2 NH 3 )[V 4 O 10 ], a member of the second group.
A mixture of 0.225 gram of V 2 O 5 , 0.201 gram of DABCO and 10 milliliters of water was heated at 170° C. and after 45 hours there was recovered 0.127 gram of a solid whose composition was found to be (HN(C 2 H 4 ) 3 NH)[V 6 O 14 ]. H 2 O, another member of the second group.
A mixture of 0.192 gram of V 2 O 5 , 0.042 gram of ZnO, 10 milliliters of water and 0.2 milliliter of en was heated at 170° C. and after 66 hours there was recovered 0.187 gram of a solid whose composition was found to be (en) 2 Zn[V 6 O 14 ], a member of the first group.
A mixture of 0.5 gram of nickel acetate, 0.181 gram of V 2 O 5 , 0.45 milliliter of ethylenediamine and 8.0 milliliters of water was heated to 200° C. After 74 hours, there was recovered a cluster of black crystals of (en) 2 Ni[V 6 O 14 ], another member of the first group.
A mixture of 0.51 gram of copper chloride dehydrate, 0.181 gram of V 2 O 5 , 0.45 milliliter of ethylenediamine and 8.0 milliliters of water was heated at 170° C. After 42 hours, there was recovered crystals of [(en) 2 Cu] 2 [V 10 O 25 ], also a member of the first group.
A mixture of 0.17 gram of copper chloride dihydrate, 0.181 gram of V 2 O 5 , 0.28 milliliter of ethylenediamine was heated to 170° C. After 65 hours, there was recovered 0.1743 gram of (en) 2 Cu[V 6 O 14 ], also of the first group.
A mixture of 0.34 gram of copper chloride dihydrate, 0.181 gram of V 2 O 5 , 0.8 milliliter of ethylenediamine and 8.0 milliliters of water was heated to 125° C. After 68 hours there was recovered 0.215 gram of a solid of which most was (en) 2 Cu[V 6 O 16 ] and some was (en)Cu[V 2 O 6 ], members of the first group. | A number of layered vanadium oxide crystalline compositions are prepared by simple hydrothermal reactions. Generally, the compositions comprise parallel layers of mixed valence vanadium oxides with guest cations intercalated between the layers. The guest cations may comprise metal coordination complexes with bidentate ligands, monomeric ammonium or diammonium cations, or mixtures of alkali metal cations with monomeric ammonium cation or diammonium cations. | 2 |
BACKGROUND OF THE INVENTION
The present invention broadly relates to the process of replacing full bobbins by empty bobbins at a spinning machine and pertains, more specifically, to a new and improved method of automatically exchanging full bobbins for empty bobbins at a flyer, i.e. a flyer frame or roving frame. The present invention also relates to a new and improved apparatus for automatically exchanging full bobbins for empty bobbins at a flyer, i.e. a flyer frame or roving frame.
Generally speaking, the present invention relates to a new and improved method of the type as described and which method may encompass the steps of tilting the full bobbins out of their substantially vertical operating position into an inclined position, lifting the full bobbins in their inclined position to doff the full bobbins and bringing the full bobbins into a substantially vertical position. The method includes in analogous manner the steps of tilting the empty bobbins out of a substantially vertical position into an inclined position, lowering the empty bobbins in the inclined position and bringing the empty bobbins into their substantially vertical operating position. The replacement of full bobbins by empty bobbins is accomplished by a doffing apparatus separate from the flyer.
In a known apparatus for automatically doffing cops or full bobbins and replacing them with empty tubes, the predecessor of which is disclosed, for example, in U.S. Pat. No. 4,757,679, granted Jul. 19, 1988, the empty tubes are suspended at a carrier with integrated transit beam in the transport-starting position, the empty tubes having been transferred to the carrier from the suspension transport means arriving from a ring spinning machine. In substantially vertical downward travel, the carrier positions the empty tubes in two lengthwise rows at an interim or intermediate storing conveyor in the lower part of the roving frame and extending along the face of and substantially parallel to the latter, i.e. upon a conveyor comprising a plurality of pegs and displaceable by one half the longitudinal pitch between the axes of adjacent cops. The carrier is then again lifted. The conveyor is displaced by a half of the pitch with respect to the arrangement or layout of the full bobbins in the flyer. Substantially at the level of the flyer support bed, the flyer comprises a horizontally disposed guide bar which extends over the entire length of the machine and projects at one end therefrom by a certain distance, and a doffing carriage is mobile along the entire machine face by means of the aforesaid guide bar.
In the vertical position the doffing carriage is aligned with the interim or intermediate storing conveyor and can be brought by means of a lever construction into an inclined position in which it defines an acute angle to the flyer. In this inclined position the doffing carriage is aligned with a cop carrier which has been lowered from the operating or spinning position and tilted into an inclined position, and which cop carrier holds at spindles the full bobbins to be replaced by empty tubes. At the lower end of its pneumatic cylinder the doffing carriage has twelve gripping elements by means of which it doffs the full bobbins or cops from the cop carrier in groups and places them on the pegs of the interim storing conveyor between the empty bobbins or tubes which are already present thereupon. When the whole flyer has been cleared the interim storing conveyor is again displaced by a half pitch, i.e. by one half the longitudinal distance between the axes of adjacent full bobbins. The doffing carriage is now in a position to lift the empty bobbins or tubes by groups from the interim storing conveyor, to bring them into the inclined position and to deposit them onto the spindles at the cop carrier. The cop carrier with the complete number of empty bobbins or tubes again tilts into the substantially horizontal position and is vertically lifted into the correct position for commencement of spinning. The carrier then is again lowered in order to engage the full bobbins at the interim storing conveyor and to vertically convey them into their upper removal or discharge position. From this removal or discharge position the full bobbins or cops are plugged onto transport means by a pivotable lever arm in order to supply subsequent ring spinning machines with roving bobbins.
The mode of operation by groups of the doffing carriage, both for the full bobbins as well as for the empty bobbins, and the interim storing at the conveyor, lead to substantially long doffing times during which spinning cannot take place. Moreover, this known flyer doffer is relatively complicated and requires a corresponding constructional expenditure. The doffing carriage is displaced after use on the guide bar to one side out of the working range of the spindles and remains in this position on the flyer, whereby substantial space is required and accessibility is strongly impaired.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved method of, and apparatus for, automatically exchanging bobbins at a flyer, and which method and apparatus do not exhibit the aforementioned drawbacks and shortcomings of the prior art.
Another and more specific object of the present invention aims at providing a new and improved method of, and apparatus for, automatically exchanging bobbins at a flyer, and which method and apparatus render possible that the doffing time can be substantially reduced.
A still further important object of the present invention is directed to a new and improved method of, and apparatus for, automatically exchanging bobbins at a flyer, and which method and apparatus permits using the simplest possible means requiring a minimum of space and substantially improving accessibility of the flyer.
Yet a further significant object of the present invention aims at providing a new and improved apparatus for automatically exchanging bobbins at a flyer, and which apparatus is of relatively simple construction and design, economical to manufacture and yet affords highly reliable operation thereof without being subject to breakdown and malfunction, and also requires a minimum of maintenance and servicing.
In keeping with the immediately preceding object, it is a further object of the present invention to provide a new and improved apparatus for automatically exchanging bobbins at a flyer, and which apparatus provides the possibility of equipping existing flyers with a doffer or doffing apparatus. In this manner, existing manually doffed flyers can be modernized, particularly flyers which have a tiltable bobbin rail or carriage.
Now in order to implement these and still further objects of the present invention which will become more readily apparent as the description proceeds, the method of the present development is manifested, among other things, by the features that all full bobbins are jointly moved out of the inclined position by means of a carrier of the doffing apparatus separate from the flyer and that all empty bobbins or tubes are jointly brought into the inclined position by means of the carrier.
As alluded to above, the invention is not only concerned with the aforementioned method aspects, but also relates to a new and improved construction of apparatus for carrying out this method. Generally speaking, the inventive apparatus comprises a flyer having a bobbin rail which can be tilted into an inclined position and which has spindles for bobbins, and a device entirely separate from the flyer. This device comprises an elevationally movable carrier with gripping means for the bobbins. The carrier extends over the full working length of the flyer.
To achieve the aforementioned measures, the inventive apparatus, in its more specific aspects, is structured such that the carrier is movable between a substantially vertical path of motion and an inclined path of motion corresponding to the inclined position of the tiltable bobbin rail.
Due to the fact that the exchange of bobbins is accomplished in one single sequence of movements, it is now rendered possible to completely do without a doffing carriage and, optionally, automatically exchange bobbins without the need for interim storing, so that the flyer can be manufactured at favorable costs. All full bobbins can be directly removed in one operation, instead of by groups, from the tiltable bobbin rail and all empty bobbins or tubes can be deposited at the tilted bobbin rail in one operation. This time-saving operation substantially improves the efficiency of the flyer. Access to the flyer can be further improved because there is actually no need for interim or intermediate storing. The favorable space-saving design of the tiltable bobbin rail can be preferably retained since the drive mechanism does not have to be decoupled. In the event of modernizing an existing flyer, it is not required that the latter be basically redesigned, provided that the bobbin rail is structured to be tiltable or, at least, outwardly movable.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings, there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 is a diagrammatic side view of a flyer doffer provided with an apparatus constructed according to the invention;
FIG. 2 is a section taken substantially along the line II--II in FIG. 1;
FIG. 3a is a partial plan view of the bobbin rail at a first stage of the inventive method;
FIG. 3b is a partial plan view of the carrier in a corresponding superimposed position relative to the first stage of the inventive method;
FIG. 4a is a partial plan view of the bobbin rail at a second stage of the inventive method;
FIG. 4b is a partial plan view of the carrier in a corresponding superimposed position relative to the second stage of the inventive method;
FIG. 5a is a partial plan view of the bobbin rail at a third stage of the inventive method;
FIG. 5b is a partial plan view of the carrier in a corresponding superimposed position relative to the third stage of the inventive method;
FIG. 6a is a partial plan view of the bobbin rail at a fourth stage of the inventive method;
FIG. 6b is a partial plan view of the carrier in a corresponding superimposed position relative to the fourth stage of the inventive method;
FIG. 7 is a fragmentary side view of the flyer doffer depicted in FIG. 1 but showing an alternative embodiment with respect to the lifting mechanism for the carrier;
FIG. 8 is a section taken substantially along the line VIII--VIII in FIG. 7;
FIG. 9 is a partial sectional view depicting in an enlarged showing a preferred embodiment of the mounting of a gripper element in the carrier depicted in FIGS. 1 and 7;
FIG. 10 is a section through a first exemplary embodiment of a gripper-bobbin connection in a flyer doffer as depicted in FIGS. 1 or 7;
FIG. 11 is a section through a second exemplary embodiment of a gripper-bobbin connection in a flyer doffer as depicted in FIGS. 1 or 7;
FIG. 12 is a section through a third exemplary embodiment of a gripper-bobbin connection in a flyer doffer as depicted in FIGS. 1 or 7;
FIG. 13 is a partial section through a part of the third exemplary embodiment of the gripper-bobbin connection as illustrated in FIG. 12 and incorporating a modification of a portion of the gripper-bobbin connection;
FIG. 14 is a diagrammatic side view of a second flyer doffer provided with an apparatus constructed according to the invention;
FIG. 15 is a plan view of a carrier for the second flyer doffer depicted in FIG. 14;
FIG. 16 is a diagram showing the sequence of movements during the doffing procedure in accordance with prior art methods as disclosed, for example, in the aforementioned U.S. Pat. No. 4,757,679;
FIG. 17 is a diagram showing the sequence of movements during the doffing procedure carried out with the aid of interim storing in the flyer doffer depicted in FIGS. 1 and 7;
FIG. 18 is a diagram showing the sequence of movements during the doffing procedure carried out without the aid of interim storing in the flyer doffer depicted in FIGS. 1 and 7;
FIG. 19 is a diagram showing the sequence of movements during the doffing procedure carried out with the aid of interim storing in the flyer doffer depicted in FIGS. 14 and 15;
FIG. 20 is a diagram showing the sequence of movements of the doffing procedure without the aid of interim storing in the flyer doffer depicted in FIGS. 14 and 15; and
FIG. 21 is a diagram similar to the diagram in FIG. 20 but depicting an alternative mode of operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that to simplify the showing thereof, only enough of the structure of the inventive apparatus for automatically exchanging bobbins at the flyer has been illustrated therein as is needed to enable one skilled in the art to readily understand the underlying principles and concepts of the present invention. Turning attention now specifically to FIG. 1 of the drawings, there is depicted therein by way of example and not limitation a flyer or roving frame 3 schematically illustrated only with a drafting unit or arrangement 4, a pair of flyers 5 and a bobbin rail 6. The bobbin rail 6 is depicted after having been lowered in a generally vertical direction out of its operating position and then tilted into an inclined position to define an acute angle to the vertical. Full bobbins 10, which are also known as roving bobbins or flyer bobbins, each consist of an empty bobbin or tube 11 with a sliver or fiber band package or cop 12 and are held by spindles 13 shown in broken lines in FIG. 1.
A carrier 21 with an integrated transit beam of a doffer or doffing or doffing and donning apparatus 20, which is entirely separate from the flyer or roving frame 3 and extends over the entire working length thereof, i.e. across the entire range of spinning locations of the flyer or roving frame 3, is movable or displaceable along at least two angular one-piece slide rails or tracks 22 which are bent away in the direction of the tilted bobbin rail 6 and supported by sectional supports 23 at the machine floor or base 29. Each slide rail or track 22 comprises a substantially vertical path of motion 15a and an inclined path of motion 15b which defines the same acute angle to the vertical as the inclined position of the full bobbins at the tilted bobbin rail 6.
FIG. 2 depicts in a sectional view taken substantially along the line II--II of FIG. 1 and in top plan view and on an enlarged scale an exemplary embodiment of an extruded section of a slide rail or track 22. It is readily conceivable that the carrier 21 is movable at the associated slide rail or track 22 by means of rolls or rollers 24 at the outer side or surface of an open cross-piece 26 of the associated slide rail or track 22, by means of rolls or rollers 25 at the inner side or surface of the open cross-piece 26 as well as by means of lateral guide rolls or rollers 27. The carrier 21 comprises an endless band or belt 32 which is tensioned around two deflection rolls or rollers 31 and is movable by means of a suitable drive motor 33. Holding or retaining means in the form of gripping elements 34, which will be described in greater detail in conjunction with FIG. 9, are secured at the endless band or belt 32 and arranged in a spaced relationship to one another by half a pitch 36 relative to the pitch 35 of the bobbins 10 or 11 at the tiltable bobbin rail 6 and in the spinning positions or locations, so that the gripping elements 34 are arranged with a density double that of the spinning positions or locations.
At the top or upper portion of FIG. 1 the carrier 21 is located in the discharge position for the full bobbins 10, which position is likewise the delivery-starting position for the empty bobbins or tubes 11. A suspended transport device 40 well known to the art is also arranged at this substantially vertical position. A pivotable lever arm 41 is provided for changing the position of the full bobbins 10 from the carrier 21 to the suspended transport device 40, and the position of the empty bobbins or tubes 11 from the suspended transport device 40 to the carrier 21.
Having now had the benefit of the foregoing discussion of the first exemplary embodiment of the apparatus for automatically exchanging bobbins, its mode of operation will now be described in conjunction with FIGS. 3 through 6 and is as follows:
The full bobbins 10 are to be replaced by the empty bobbins or tubes 11. The full bobbins 10 are lowered with the bobbin rail 6 in a substantially vertical direction and brought into the inclined position which defines an acute angle to the vertical. The empty bobbins or tubes 11 are now located at the carrier 21 in the delivery-starting position. The carrier 21 together with the empty bobbins or tubes 11 is lowered initially or at first in a substantially vertical direction and then, by virtue of the angular shape of the slide rails or tracks 22, in an oblique direction into the inclined position. This downward travel is effected by means of at least two cables or ropes 42 which are slung or trained around deflection rolls or rollers 43. Thus the empty bobbins or tubes 11 are lowered into the inclined position thereof in a continuous sequence of movements without interim or intermediate storing.
The empty gripping elements 34 of the carrier 21 are aligned during the continuous sequence of movements with the full bobbins 10. In this manner, the empty bobbins or tubes 11 move into empty spaces 46 located between the full bobbins 10 as depicted in FIG. 3. The empty gripping elements 34 now grip or engage the full bobbins 10. In this inclined position the carrier 21 with full bobbins 10 and empty bobbins or tubes 11 is raised above the spindles 13 (FIG. 5a). The motor or drive means 33 is then set in motion and displaces the endless band or belt 32 by the half pitch 36 in the direction of the arrow 47 as shown in FIGS. 4b and 5b. The empty bobbins or tubes 11 are now aligned with the spindles 13. The carrier 21 is again lowered into the inclined position and deposits the empty bobbins or tubes 11 onto the spindles 13 at the respective working positions. The carrier 21 now contains only the full bobbins 10 located in the inclined position as shown in FIG. 6b. The full bobbins 10 are now lifted or conveyed out of this inclined position in a continuous movement, i.e. without interim or intermediate storing, into the substantially vertical discharge position. The carrier 21 thus simultaneously serves as an intersection location for the empty bobbins or tubes 11 and for the full bobbins 10. The interim or intermediate storing location 49 shown in broken lines in FIG. 1 is thus unnecessary in this first exemplary embodiment of the apparatus for automatically exchanging bobbins. This process or sequence of movements is diagrammatically illustrated in FIG. 18.
In the exemplary embodiment of FIG. 7, which is a variant of the first exemplary embodiment of the apparatus for automatically exchanging bobbins, the lifting mechanism for the carrier 21 is realized or effected by means of a substantially vertically adjustable slide block 55. This slide block 55 and a threaded or screw spindle 57, which serves for elevational adjustment and is driven by a suitable motor 56, are integrated in a substantially vertical sectional support 23a. Form-locked spindles, toothed racks, bands and the like could be used in place of the threaded or screw spindle 57. The adjustable slide block 55 comprises a lug 60 which projects through a vertical opening or slot 61 of the substantially vertical sectional support 23a. A hinged rod 62 connects the lug 60 to the carrier 21, optionally in conjunction with a cylinder 63. Reliable downward travel of the carrier 21 is ensured by this alternative embodiment. The cables or ropes 42 tensioned or trained over deflection rolls or rollers 43 can be retained for the purpose of weight compensation for the carrier 21. In FIG. 8, the positions of the lateral guide rolls or rollers 27 are indicated by broken lines within the slide rail 22a which is slightly modified with respect to the construction depicted in FIG. 2.
Reliable operation or functioning of the apparatus constructed according to the invention is determined to a very great extent by rigid guides or guidances. FIG. 2 depicts a suitable manner of guiding the carrier 21 at the angular slide rails or tracks 22 or 22a (FIG. 8). The gripping elements 34 must also be rigidly guided, for example, as shown in FIG. 9. The gripping elements 34 are connected with the endless band or belt 32 by means of gripper holders 68. In an analogous manner with respect to the construction in FIG. 2, rolls or rollers 25.1 and lateral guide rolls or rollers 27.1 bear against a sectional rail or track 69. Rolls or rollers 24.1 are not provided due to the provision of ribs 70 at the sectional rail or track 69. This sectional rail or track 69 advantageously encloses the full length of the endless band or belt 32, with horizontal cut-outs 71 being provided for the deflection rolls or rollers 31. The gripper holders 68 project from the sectional rail or track 69 through a continuous slot 72 located at the lower portion of the sectional rail or track 69.
The connection between the gripping element 34 and the empty bobbin or tube 11 also must be structured to be rigid and inflexible. FIGS. 10 through 13 show possible exemplary embodiments of such connections. The right-hand half of FIG. 10 shows a gripping element 34.1 with a stiffener or support means in the form of an optionally interrupted cylindrical jacket or shell 80 which partially extends over the length of the full bobbin 10 or the empty bobbin or tube 11. The left-hand half of FIG. 10 shows a cylindrical jacket or shell 80.1 which can penetrate into the end face of the empty bobbin or tube 11.
FIG. 11 shows a gripping element 34.2 with support means in the form of a pressure body 82 which bears upon the end face of the empty bobbin or tube 11. This pressure body 82 is retained by a spring 83. FIG. 12 shows a gripping element 34.3, the stiffener of which was inspired by a bottle stopper. Elastic rings 84 on a pin or bolt 85 expand at the inner side or wall of the empty bobbin tube 11, while an outer member 86 at the pin or bolt 85 bears upon the end face of the empty bobbin or tube 11. The pin or bolt 85 possesses an annular recess 87 and a spring element 89 which cooperates with a square element 90 of a latch 91. The latch 91 is firmly but rotatedly connected to the gripper holder 68 in such a manner that the spring element 89 turns the square element 90 and thus the latch 91 through 90° during upward travel or movement of the pin or bolt 85. In this manner, the pin or bolt 85 can be latched and unlatched. A variant is shown in FIG. 13 in that a latch 91.1 is secured to the pin or bolt 85 and a spring element 89.1 is secured to the gripper holder 68.
A second exemplary embodiment of the apparatus constructed according to the invention is illustrated in FIG. 14 as a completely different flyer doffer or doffing apparatus 20.1, in which various parts are shown in a superimposed arrangement. A carrier 21.1, illustrated here in double for ease in understanding, is separated from a stationary or immovable transit beam 95. A slide block 55.1 is substantially vertically movable in an associated sectional support 23b, for example, by means of the screw spindle 57 not particularly illustrated in FIG. 14. The inclined path of motion 15b is hingedly and adjustably connected to the slide block 55.1 by means of a hydraulic or pneumatic cylinder 96. The carrier 21.1 is movable by means of a sliding or rolling element 97 and a cylinder 63.1 at this inclined path of motion 15b, which can be pivoted into the substantially vertical path of motion 15a. Additional retaining or holding means in the form of inflatable cuff grippers 99 constituting pneumatically actuatable gripping means are arranged on both sides of a holding beam 101 and cooperate with the gripping elements 34 of the stationary transit beam 95. With regard to the design of the inflatable cuff grippers 99 and the nature of their mounting on the holding beam 101, reference is made to European Patent Application No. 0,303,877, published Feb. 22, 1989 (and the cognate U.S. patent application Ser. No. 07/233,564). The holding beam 101 can be either fixed in the longitudinal direction of the flyer as illustrated in the right-hand half of FIG. 15 or structured such that it is displaceable through at least a half pitch 36 as depicted in the left-hand half of FIG. 15. In the latter case the longitudinal displacement device can comprise a toothed bar 103 on the holding beam 101 and a driveable pinion 104 on the retaining arm 105. Empty bobbins or tubes 11 as well as full bobbins 10 can be picked up by means of the inflatable cuff grippers 99. The same number of grippers or twice the number of grippers can be provided on the holding beam 101, always in relation to the number of spindles 13 at the tiltable bobbin rail 6. In the event of twice the number of grippers 99 and 99.1, separate air lines 107 and 107.1 would be required. The additional grippers 99.1, which are made somewhat smaller than the inflatable cuff grippers 99 because of space conditions, are depicted or indicated in broken lines in FIG. 15.
The mode of operation of the second exemplary embodiment of the apparatus constructed according to the invention will now be discussed in greater detail in conjunction with FIGS. 14 and 19 and is as follows:
The carrier 21.1 travels empty, at first along the substantially vertical path of motion 15a and then along the inclined path of motion 15b, picks up the full bobbins 10 with the inflatable cuff grippers 99 being guided over the full bobbins 10 from above, and places the latter in the interim or intermediate storing location 49. The empty carrier 21.1 subsequently collects the empty bobbins or tubes 11 from the stationary transit beam 95 with the inflatable cuff grippers 99 being guided over the empty bobbin or tubes 11 from above. Therefore, attention should be paid to the fact that the dimension of any possible flange at the bottom end of the bobbin may have to be reduced. The empty bobbins or tubes 11 are brought again via the vertical path of motion 15a and the inclined path of motion 15b into the inclined position and are deposited onto the spindles 13. The full bobbins 10 are subsequently guided during a substantially upward travel from the interim or intermediate storing location 49 to the stationary transit beam 95. Any longitudinal displacements are unnecessary in this case.
Another mode of operation is illustrated in FIG. 20. It is analogously carried out in accordance with the description of the diagram in FIG. 18. FIG. 21 shows a further mode of operation which is briefly considered as follows:
The carrier 21.1 travels empty into the inclined position, collects the full bobbins 10 and transfers the latter to the stationary transit beam 95. Picking up the empty bobbins or tubes 11 is then essentially simultaneously effected with the discharge of the full bobbins 10.
It should be clear that the mode of operation illustrated in FIG. 17 can be straightforwardly carried out by means of the doffer or doffing apparatus 20 depicted in FIG. 1 when the inclined path of motion 15b is pivotably connected with the substantially vertical path of motion 15a instead of being fixedly connected thereto.
In order to provide a still better understanding of the inventive method, a comparison with the prior art is schematically illustrated in FIGS. 16 through 21. It should be noted that, apart from the horizontal connecting lines which do not represent motion or travel, a continuous line signifies the transport of empty bobbins or tubes 11 and a continuous line with transverse hatching represents the transport of full bobbins 10. A broken line signifies that the carrier 21 or 21.1 or a doffing carriage 106 (FIG. 16) is moved without bobbins.
The following points have been considered in the comparison of the prior art method steps depicted in FIG. 16 with the inventive steps depicted in FIGS. 17 through 21:
1.1 Is the transit beam integrated with the carrier 21?
1.2 What is the number of gripper means or gripping elements 34 at the carrier 21? Such number is in relation to that of the spindles 13 at the tiltable bobbin rail 6.
1.3 Is the carrier 21 or 21.1 longitudinally displaceable in the inclined position by a half pitch 36?
2.1 Is the transit beam 95 separate from the carrier 21.1?
2.2 What is the number of inflatable cuff grippers 99 or 99.1 at the carrier 21.1?
2.3 What is the number of gripping elements 34 at the transit beam 95?
3.1 Is an interim or intermediate storing location 49 necessary?
3.2 What is the number of pegs at the interim or intermediate storing location 49?
3.3 Is a longitudinal displacement of the interim or intermediate storing location necessary?
______________________________________Fig. 16 17** 18 19 20 21______________________________________1.1 yes yes yes no no no1.2 same same double -- -- --1.3 no needless* yes no yes needless*2.1 no no no yes yes yes2.2 -- -- -- same double double2.3 -- -- -- same same double3.1 yes yes no yes no no3.2 double double -- same -- --3.3 yes no -- no -- --______________________________________ *The longitudinal displacement takes place in the horizontal position. **A longitudinal displacement is necessary four times.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. | The doffing time of a flyer can be considerably shortened when a carrier carrying empty bobbins is brought in a single sequence of movements, without interim or intermediate storing, from a substantially vertical transport-starting position into a predetermined inclined position and thus into alignment with an inclined bobbin rail. The full bobbins are accordingly conveyed in analogous manner. | 3 |
BACKGROUND
Field
This technology as disclosed herein relates generally to two force members and, more particularly, to a link having an energy absorbing component.
Background
Current solutions for providing an energy absorbing link, are limited or not in practice at all. One possible example of a current practice is the use of metallic solutions such as corrugated and slotted tubes, however, these solutions are typically heavy and are not typically capable of absorbing a sufficient amount of energy. Energy-absorbing bearings are feasible but have a limited stroking distance to absorb an amount of energy that is adequate for what is needed. Fluid-filled struts are in practice for energy absorbing links.
An energy-absorbing link structure that attenuates the energy produced by heavy mass items is needed that is lighter in weight than prior solutions and that has a longer stroke length during maximum load conditions.
SUMMARY
The technology as disclosed herein is a method and apparatus for a two force structural member that is utilized as a link between two heavy structures comprising an energy absorbing tab adjacent a mounting hole of a link member. One embodiment of the technology is a composite structural transmission support link which has a novel integral energy-absorbing feature. The link can be a two-force member that can carry structural loads up an ultimate load. When loaded beyond ultimate load, such as in a crash event, features in the design allow sections of the link to fail in a progressive manner to absorb energy over a defined stroking distance. The energy absorbing link technology as disclosed can be utilized to connect or link two heavy structures.
A link can be designed to support a heavy mass during normal operations of the heavy mass components up to an ultimate load. When this load is exceeded, for example, during a crash event, the energy absorbing technology as disclosed is designed to attenuate energy of the heavy mass by means of controlled failure through a defined stroke distance—which acts to shed energy of the system, for example, an aircraft system. After completion of the stroke of the mass over a defined distance, the link remains intact and imparts a reduced force to the heavy structure, such as an airframe, during the stroke.
In one implementation of the technology as disclosed, a slot can be machined or formed into a link to form a weak region under a bushing area. With one implementation, the weak region can be positioned between two thru-holes used to attach the link between two heavy structures, which can absorb compression loads. With another implementation, the weak region can be position on a far side of a thru-hole between the thru-hole and the end of the link, which can absorb tension loads (tensile loads).
When the component is loaded in compression, the slot can absorb the energy via progressive failure. Ply drops serve as sacrificial components that will fail when stressed beyond maximum capacity, thereby reducing the initial load spike. Ply drops (ply drop-offs) are thickness variations in the laminate composite accomplished by dropping or eliminating plies along the length where, in this case, the ply drops are designed as fail points forming a weak region. This invention has significant weight advantages over a fluid filled strut, with similar energy absorbing capabilities.
One implementation for the basic design of a link can include a composite tube with a rectangular shaped cross section. Cutouts can be formed on each end of the link to act to form a clevis joint. Metallic bushings can be installed through the thru-holes in each arm of the clevis.
The technology as disclosed can be a two-force structural member that is loaded double-shear when subjected to a tensile or compressive load. A novel feature of this technology is a weak area designed into a section of the link on each clevis arm face, adjacent to the thru-hole, through which the clevis pin is inserted. The material in this area can form a slot with a width that roughly matches the outer diameter of the bushing installed through each clevis arm thru-hole. This feature is positioned so that, when the part is loaded in compression, the pin bushing fails and the composite material in the slot area and the ensuing crushing action absorbs energy.
The combination of the length of the slot and depth of the clevis arms define the stroke distance for energy absorption. The layup of the composite material in the slot can be configured to fail through progressive crushing at a relatively constant load, while the link stays intact during the failure event. The slot feature can be formed by a variation in the composite ply layup compared to the link layup, which may include: composite ply drop-offs; composite ply breaks; or, a machined taper in the slot. Ply breaks are when the fibers in a single composite ply are intentionally cut or a gap is left between two different plies.
An energy-absorbing (EA) slot can be integral to the link and can be designed to fail by crushing during a max-load event, thereby attenuating the energy of a heavy mass. One (1) EA slot at each end of link can effectively double the stroking distance and energy absorbed. A slot can be machined or formed into the EA link to form a ‘weak’ region adjacent a bushing bearing area when loaded in compression. If the bushing bearing is appropriately spaced from the end of the link, a slot can be formed in the EA link between the thru-hole and the end of the link to form a weak region adjacent a bushing area when loaded in tension. The slot can absorb energy by the crushing of the material of the slot. The slot can be formed of a composite material.
In another implementation, a gradual variation in the number of plies (ply drops) can be utilized to act as sacrificial components that will fail when stressed beyond maximum capacity to initiate crushing and reduce an initial load spike. The thickness and layup orientation of composite material in the slot can be tuned for a required energy attenuation.
One implementation of a two-force member energy-absorbing link structure can include an elongated structural member having first and second opposing ends and a lengthwise extending central axis where at least the first and second opposing ends of the elongated structural member is constructed of a primary material having a strength characteristic sufficient to link together two structures. A thru-hole can extend substantially orthogonally with respect to the central axis and through one or more of the first and second ends.
A section of the elongated structural member constructed of a secondary material and having a lesser strength characteristic than the strength characteristic of the material sufficient to link the two structures can be adjacent the thru-hole. The section can extend a lengthwise distance substantially along a direction that the lengthwise extending central axis extends and the section can extend from a point of the material proximate and adjacent the thru-hole. In one implementation, the elongated structural member can be a tubular elongated member, and one or more of the first and second opposing distal ends can have a u-shaped clevis structure with opposing first and second prong members forming the u-shaped clevis structure.
One implementation of the technology as disclosed herein can be a two-force member energy-absorbing link structure including an elongated structural member having first and second opposing distal ends and a lengthwise extending central axis where at least the first and second opposing distal ends of the elongated structural member are constructed with a primary material thickness having a strength characteristic sufficient to link together two structures. A thru-hole can extend substantially orthogonally with respect to the central axis and through one or more of the first and second distal ends. A recessed cutaway slot section of the elongated structural member, i.e. the link, can be constructed having a lesser thickness and lesser strength characteristic than the strength characteristic of the material sufficient to link the two structures, wherein the section extends a lengthwise distance substantially along a direction that the lengthwise extending central axis extends and wherein the section extends from a point of the material proximate and adjacent the thru-hole.
The level of energy absorbed can be adjusted through a combination of the design of the layup and form features. Composite materials can be utilized to enhance the performance parameters of the design. The benefits of a design using high performance composite materials is that very high levels of specific-sustained crush stress (per unit energy-absorption, in Joules/gm) may be obtained throughout a relatively large stroke distance, compared to metallic designs. This is particularly useful approach where the structural members also have the ability to attenuate the energy of heavy mass items, such as a rotorcraft transmission during a crash, for virtually no weight penalty.
The features, functions, and advantages that have been discussed can be achieved independently in various implementations or may be combined in yet other implementations, further details of which can be seen with reference to the following description and drawings.
These and other advantageous features of the present technology as disclosed will be in part apparent and in part pointed out herein below.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present technology as disclosed, reference may be made to the accompanying drawings in which:
FIG. 1A is an illustration of two heavy mass structures being connected by links;
FIG. 1B is a magnified view of an encircled portion of FIG. 1A illustrating two links, which can be used to connect two heavy mass structures;
FIG. 2A is a sectional view of a clevis of a link;
FIG. 2B is another sectional view of a clevis and bushing bearing of a link;
FIG. 3A is a front sectional view of a clevis of a link;
FIG. 3B is a perspective view of a clevis of a link;
FIG. 3C is a magnified view of a portion of FIG. 3B , providing a sectional perspective view of a slot area;
FIG. 4A is a magnified view of one end of a link prior a controlled failure; and
FIG. 4B is a magnified view of one end of a link after a controlled failure.
While the technology as disclosed is susceptible to various modifications and alternative forms, specific implementations thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the disclosure to the particular implementations as disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present technology as disclosed and as defined by the appended claims.
DESCRIPTION
According to the implementation(s) of the present technology as disclosed, various views are illustrated in FIG. 1-4 and like reference numerals are being used consistently throughout to refer to like and corresponding parts of the technology for all of the various views and figures of the drawing. Also, please note that the first digit(s) of the reference number for a given item or part of the technology should correspond to the figure number in which the item or part is first identified.
One implementation of the present technology as disclosed (comprising an energy-absorbing slot feature) teaches a novel apparatus and method for an energy-absorbing link.
The details of the technology as disclosed and various implementations can be better understood by referring to the figures of the drawings. Referring to FIGS. 1A and 1B , an illustration of two heavy mass structures being connected by a link system 106 is shown, and an illustration of two links 108 and 110 , which can be used to link two heavy mass structures, is shown. A two-force member energy-absorbing link structure 110 (see FIG. 1B ) is shown, which can be connected between to two heavy structures, as illustrated in FIG. 1A , a first heavy structure 104 and a second heavy structure 102 , (see FIG. 1A ) of the two structure system 100 . As illustrated in FIG. 1A , for example, the first heavy structure can be an aircraft main structure 104 and the second heavy structure can be an aircraft drive system 102 . Encircled area 106 is further illustrated in FIG. 1B .
Referring to FIG. 1B , an elongated structural member, which is a link 110 , is shown having first 112 and second 114 opposing ends. The portion of the link system 106 as illustrated shows a first link 108 and a second link 110 . First link 108 does not illustrate the present technology as disclosed herein while second link 110 does. Both the first link 108 and the second link 110 are connected by their respective second opposing ends 114 to a mounting structure 116 . The second link 110 has a lengthwise extending central axis (identified by reference numeral 214 in FIGS. 2B and 3A ) where at least the first and second opposing ends 112 , 114 of the link 110 are constructed of a primary material 134 having a strength characteristic sufficient to link together two structures (for example, structures 104 and 102 ).
A first thru-hole 118 and a second thru-hole 120 can extend substantially orthogonally with respect to the central axis (see item 214 of FIGS. 2B and 3A ) and through one or more of the first 112 and second 114 opposing ends. A first section 126 and/or a second section 128 of the elongated structural member, which is the second link 110 , can be constructed of secondary material having a lesser strength characteristic than the strength characteristic of the material sufficient to link the first heavy structure and the second heavy structure. The first and second sections 126 and 128 can extend a lengthwise distance substantially along a direction that the lengthwise extending central axis 214 extends. The first and second sections can extend from a location 124 of the material proximate and adjacent the thru-hole.
In one implementation of the technology, the two-force member energy-absorbing link 110 can be constructed such that the elongated structural member, link 110 , is a tubular elongated member. The two-force member energy-absorbing link 110 as illustrated where one or more of the first 112 and second 114 opposing distal ends have a u-shaped clevis structure with opposing first 132 and second 130 prong members (i.e. arms) forming the u-shaped 122 clevis structure. The first and second thru-holes, as illustrated at 118 and 120 , can extend through one or more of the first 130 and second 132 prong members.
The section, illustrated by 126 or 128 , of the elongated structural member 110 can be constructed of a secondary material and can be an elongated slot 126 or 128 extending a lengthwise distance. The first and second sections of weakened material 126 and 128 of the elongated structural member, link 110 , can be formed in the primary material as a weakened region of the elongated structural member, i.e. the link 110 , to allow the weakened sections 126 and 128 to crush when sufficient compression loads are applied to the elongated structural member in the direction that the lengthwise extending central axis 214 extends.
Referring to FIGS. 2A and 2B , a sectional view 200 of first and second arms 130 and 132 of a link is shown. Referring to FIG. 2B , another sectional view of the clevis arms 130 and 132 and bushing bearing 210 of a link is shown. The section (i.e. slot) 126 can be formed with ply-drops 206 and 208 proximate the thru-hole 118 to act as a weakened area to induce a controlled failure and to initiate crushing of the slot 126 constructed of a secondary material to reduce an initial load spike. The slot 126 comprising the secondary material can also be a recess 202 . With one implementation of the technology as disclosed, the section of secondary material 126 , which can be a recessed slot 202 , can be formed having lengthwise slits 216 (See FIG. 2B ) extending at least partially from one end of the slot to the opposing end of the slot in the direction that the lengthwise extending central axis extends.
With one implementation of the technology as disclosed a two-force member energy-absorbing link structure can include an elongated tubular member—i.e. a link 110 . The tubular member can have a rectangular cross section. The link can have first and second opposing distal ends and a lengthwise extending central axis where the elongated structural member is constructed of a primary material having a strength characteristic sufficient to link together two structures. With this implementation a thru-hole can extend substantially orthogonally with respect to the central axis and through one or more of the first and second distal ends. A section 126 of the elongated structural member can be constructed of secondary material 134 having a lesser strength characteristic than the strength characteristic of the material sufficient to link two structures and said section can extend a lengthwise distance 212 substantially along a direction that the lengthwise extending central axis 214 extends and said section extends from a location 124 of the material proximate and adjacent the through hole.
The first and second opposing ends can have a u-shaped clevis structure 204 with opposing first 130 and second 132 prong members forming the u-shaped clevis structure 204 . The thru-hole 118 extends through one or more of the first and second prong members 130 , 132 . The section of the elongated structural member constructed of a secondary material is an elongated slot 126 extending a lengthwise distance 212 (see FIG. 2B ). In one implementation of the technology, the section of the elongated tubular member can be formed in the primary material as a weakened region of the elongated tubular member to allow the section to crush when sufficient compression loads are applied to the elongated tubular member in the direction that the lengthwise extending central axis 214 extends. The section can be formed with ply-drops 206 proximate the thru-hole 118 to act to initiate crushing of the secondary material to reduce an initial load spike. The section can be formed having lengthwise slits 216 extending at least partially in the direction that the lengthwise extending central axis extends.
Referring to FIGS. 3A, 3B and 3C , a front sectional view of a clevis of a link is shown, a perspective view of a clevis of a link is shown and a sectional perspective view a slot area is shown. An elongated structural member, i.e. the link 110 , can have first and second opposing ends. The first end 112 is shown in FIG. 3A . A lengthwise extending central axis 214 can extend in the direction illustrated where at least the first and second opposing ends of the link 110 is constructed having a primary material thickness having a strength characteristic sufficient to link together two structures.
As can be seen, a thru-hole 118 extends substantially orthogonally with respect to the central axis 214 . A recessed cutaway slot 202 section in the link 110 is shown and can be constructed of a material having a lesser thickness and lesser strength characteristic than the strength characteristic of the material sufficient to link the two structures. The recessed cutaway slot 202 can extend a lengthwise distance substantially along a direction that the lengthwise extending central axis extends and said section can extend from a location proximate and adjacent the thru-hole.
The first and second opposing ends can have a u-shaped 204 clevis structure with opposing first and second arm members forming the u-shaped clevis structure. The section can be formed with ply-drops 206 proximate the thru-hole 118 to allow for the initiation of the crushing of the secondary material to reduce an initial load spike. The section can be formed having lengthwise slits 216 extending at least partially in the direction that the lengthwise extending central axis extends.
Referring to FIGS. 4A and 4B , an illustration is provided for one end of a link before ( FIG. 4A ) and after ( FIG. 4B ) a controlled failure. A view of one end 114 of a link 110 is shown. The link 110 is shown mounted to a structure 116 using the clevis 122 and a mounting bolt 402 and washer 403 . The bolt 402 is shown extending through a thru-hole 120 of the clevis 122 and attaching the link 110 to the structure 116 . The link 110 is constructed of a primary material 134 . The link 110 can have a section of weakened material 128 . The section of weakened material 128 can be an elongated slot 404 that extends lengthwise in the same direction as the central axis 214 . The elongated slot 404 can also have a recess 406 as illustrated where material can be removed further weakening the area. FIG. 4B illustrates one end 114 of the link 110 after a controlled failure where the bolt 402 has traversed along the stroke distance 408 and proximately along the same direction as the axis 214 , thereby crushing the section of weakened material 128 , while bolt 402 remains sufficiently intact such that the link 110 is still mounted to the structure 116 .
The various energy-absorbing link examples shown above illustrate a link between two heavy structures. A user of the present technology as disclosed may choose any of the above implementations, or an equivalent thereof, depending upon the desired application. In this regard, it is recognized that various forms of the subject energy-absorbing link could be utilized without departing from the scope of the present invention.
As is evident from the foregoing description, certain aspects of the present technology as disclosed are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the scope of the present technology as disclosed and claimed.
Other aspects, objects and advantages of the present technology as disclosed can be obtained from a study of the drawings, the disclosure and the appended claims. | An apparatus and method for a composite structural aircraft transmission support link having an integral energy-absorbing feature is disclosed. The link is a two-force member that can carry structural loads up an ultimate load. When loaded beyond ultimate load the design allows sections of the link to fail in a controlled and progressive manner, so that energy is absorbed over a defined stroking distance. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to monoclonal antibodies against autoimmune RNA proteins and to immunological and diagnostic testing methods involving the use of such monoclonal antibodies.
SUMMARY OF THE INVENTION
The present invention comprises monoclonal antibodies against an autoimmune RNA protein. These antibodies are generated by a continuous hybridoma cell line which is produced by fusing a myeloma cell with a cell capable of producing antibodies against the autoimmune RNA protein.
The monoclonal antibodies may be used to detect the presence of autoimmune RNA protein in a biological sample by assaying for antibody-RNA protein reaction product in the sample. The monoclonal antibodies of the present invention may also be used to detect the presence of antibodies to the autoimmune RNA protein in a biological sample, and so may be used to screen for systemic lupus erythematosus, subacute cutaneous lupus erythematosus, Sjogren's syndrome, congenital complete heart block and other disorders involving the presence of antibodies to autoimmune RNA protein. In order to detect the presence of antibodies in a sample, the monoclonal antibodies are first treated with a stoichiometric excess of autoimmune RNA protein. The treated monoclonal antibodies are then contacted with the sample. Presence of antibodies in the sample is detected by assaying for antibody-RNA protein reaction which occurs after contacting the sample with the treated monoclonal antibodies.
The present invention further comprises a kit for use in assaying for antibodies against an autoimmune RNA protein comprising a first medium comprising the monoclonal antibodies of the present invention, a second medium comprising animal extract containing a stoichiometric excess of autoimmune RNA protein, and a third medium comprising an enzyme-labelled immunological conjugate to antibodies against the autoimmune RNA protein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to monoclonal antibodies against autoimmune RNA proteins and to methods of preparing and using such monoclonal antibodies. Such autoimmune RNA proteins include La/SSB, Ro/SSA, nRNP and Sm. Antibodies against these proteins are known to occur at high levels in many patients suffering from autoimmune disorders such as systemic lupus erythematosus (SLE) and Sjogren's syndrome. The monoclonal antibodies of the present invention offer an economical and efficient means for diagnosing and screening for these autoimmune disorders.
PURIFICATION OF SELECTED AUTOIMMUNE RNA PROTEIN
In accordance with the present invention, monoclonal antibodies are prepared against a selected autoimmune RNA protein. While any of the above-identified RNA proteins may be selected, one RNA protein is La/SSB. When the RNA protein is La/SSB, one preferred variety is bovine La/SSB.
The first step in producing monoclonal antibodies against the selected autoimmune RNA protein is the purification of the selected autoimmune RNA protein, preferably from a mammal such as a human or bovine animal, and more preferably from the spleen or thymus of such a mammal. If the selected protein is unavailable from the off-the-shelf sources, it may be obtained by extraction and separation methods, such as the affinity chromatography methods described by Harley et al. (J. Rheumatol. 11, pp. 309-14 [1984]) and Akizuki et al. (J. Immunol. 119, pp. 932-38 [1977]). In these methods an affinity column containing antibody activity in the selected autoimmune RNA protein is utilized to separate the autoimmune RNA protein from other tissue components. Preferably, the affinity column is formed from CNBr-activated Sepharose 4B which is coupled to the purified IgG fraction from an SLE patient with precipitin to antibodies against the selected autoimmune RNA protein.
To verify that the separated fractions containing the selected autoimmune RNA protein are substantially pure, the fractions are preferably analyzed for contamination. Preferred contamination tests included sodium dodecylsulfate polyacrylamide gel electrophoresis using a silver stain, the Western blot technique, and the enzyme-linked immunoabsorbent assay (ELISA) for antibodies against the selected autoimmune RNA proteins.
If contamination studies reveal that autoimmune RNA proteins, immunoglobulins and other contaminants were separated by the above-described chromatographic procedure, these substances may be removed from the separated fraction containing the selected autoimmune RNA protein, preferably by treating the fraction with a monospecific anti-protein, by performing further anti-human immunoglobulin affinity column procedures, or by using additional physical separation procedures, including, but not limited to, gel filtration, ion exchange chromatography, isoelectric focusing, chromatofocusing and adsorption into Staph A Sepharose.
Once the necessary separation steps have been completed, the substantially pure selected autoimmune RNA protein preferably is suspended in a biologically acceptable carrier, preferably 0.02M Tris or 0.02M phosphate and 150 mM NaCl at pH 7.4. The preparation then is preferably cooled, concentrated and stored.
ANIMAL IMMUNIZATION WITH AUTOIMMUNE RNA PROTEIN
In accordance with the present invention, cells capable of producing antibodies to the selected autoimmune RNA protein are obtained by immunizing an immunoresponsive animal with the purified preparation of the selected autoimmune RNA protein. Preferably, the animal to be immunized is of a different species than the species from which the selected autoimmune RNA protein is extracted, so that immunization will cause the immunized animal to produce heteroantibodies. The animal selected for immunization is preferably a mammal, more preferably a mouse, and most preferably, a Balb/c mouse.
The animal is immunized with the preparation containing the substantially pure selected autoimmune RNA protein, preferably in combination with an equal amount of an immunological adjuvant, in an amount sufficient to generate production of substantial numbers of cells producing antibodies to the selected autoimmune RNA protein. Preferably, the animal is first injected subcutaneously with purified selected autoimmune RNA protein in an amount sufficient to initiate an immune response in the animal. The initial dosage of protein is preferably administered in combination with an equal amount of an adjuvant, such as Freund's Complete Adjuvant. In a preferred embodiment, 50 μg of purified selected autoimmune RNA protein suspended in between about 50 μl and about 300 μl, and most preferably in about 200 μl of 0.02M phosphate or Tris and 150 mM NaCl at pH 7.4, is administered to the animal by subcutaneous injection as a suspension which also contains 200 μl of Freund's Complete Adjuvant.
Fourteen days after the initial subcutaneous injection, the animal preferably is boosted by intraperitoneal injection of an additional amount of purified selected autoimmune protein, which preferably is administered is combination with an equal amount of an adjuvant, such as Freund's Incomplete Adjuvant. In a preferred embodiment, the first booster injection comprises 10 μg of purified selected autoimmune RNA protein suspended in between about 50 μl to about 250 μl, and more preferably in 200 μl of 0.02M phosphate or Tris and 150 mM NaCl at pH 7.4, and is administered to the animal in combination with 200 μl of Freund's Incomplete Adjuvant.
If required, additional booster injections may be administered to the animal. The number of dosages of such additional boosters will depend upon the animal's response to the immunization and the length of time the animal is to be maintained in an immunized state prior to recovery of antibody-producing cells from the animal. In one preferred embodiment, seven additional booster dosages of selected autoimmune protein are administered to the animal over the four month period following the first booster injection. These seven additional booster dosages preferably comprise between about 10 μg and about 100 μg of selected autoimmune RNA protein suspended in between about 50 μl and about 200 μl, and most preferably 100 μl, of 0.02M phosphate or Tris and 150 mM NaCl at pH 7.4. In this preferred embodiment, the additional booster dosages are administered without adjuvant. Preferably, the last three of such additional booster injections are administered on each of three days before antibody-producing cells are to be recovered from the animal. Each of the additional booster injections preferably is intraperitoneal, except the final injection which most preferably is administered via the tail vein.
PRODUCTION OF HYBRIDOMAS
According to the present invention, cells from the animal immunized as described above are fused with a compatible cell line to produce hybridomas capable of producing monoclonal antibodies against the selected autoimmune RNA protein against which the animal was immunized.
Cells producing antibodies to the selected autoimmune RNA protein are recovered from the immunized animal, and preferably from the animal's spleen. The cells are removed under sterile conditions and are prepared for fusion with a compatible myeloma cell line.
Preferably, the myeloma cell line is from the same animal species as the antibody-producing cell, and most preferably, both of the fused cells are murine. A preferred compatible fusion partner cell is the P3 X63-Ag86.5.3 mouse myeloma cell. Preferably, prior to fusion these cells have been suspended in a medium containing hypoxanthine/aminopterin/thymidine (HAT).
The cells recovered from the immunized animal preferably are mixed with the myeloma cells in the presence of a fusion-promoting agent, preferably polyethylene glycol (PEG). Once fusion has occurred between myeloma and antibody-producing cells, the fusion-promoting action preferably is arrested. Preferably, this arresting step is carried out by centrifuging the mixture and removing substantially all the supernatant which results in the removal of substantially all the PEG. The removed supernatant is replaced with either a HAT medium or a modified Dulbecco's minimal essential medium (DMEM).
The fused cells are next cultured in a medium selective for the growth of those hybridoma cells formed by fusing myeloma cells with antibody-producing cells. Preferably, the selective medium comprises HAT and fetal calf serum (FCS). Preferably, the selective culturing is performed by plating out the fused cells onto a 24-well polystyrene macrotiter plate having in each well a selective medium comprising a mixture of HAT and FCS.
The culture supernatant from the wells demonstrating hybridoma growth are screened to determine which of them are producing monoclonal antibodies against the selected autoimmune RNA protein. Preferably, this screening step is carried out by a modified enzyme-linked immunoabsorbent assay (ELISA) using affinity-purified autoimmune RNA protein obtained from the same species of animal as that from which the purified protein preparation used to immunize the animal, as described above, was obtained.
The hybridomas which grow in the selective culture medium are single-cell cloned. preferably, the cloning is carried out by distributing the hybridomas in the wells of 96-well polystyrene microtiter plates having in each well a nutrient medium. The nutrient medium preferably is the same preparation as that in which the fused cells were suspended and selectively cultured, as described above. Preferably, the nutrient medium also contains fetal bovine serum. More preferably, the fetal bovine serum used is Hybrisure (Hazelton-Dutchland) which was tested to assure it will sustain hybridoma growth. The plates containing the hybridomas in nutrient medium are incubated until the hybridomas have colonized.
After the hybridomas have colonized, as described above, the supernatants are screened, as described above. The cloned cells which are producing antibodies are expanded and used as the source of the monoclonal antibody-producing hybridoma cells.
The above described procedures for fusion, selective hybridoma growth and cloning are adapted from those described by Galfre & Milistein (Methods of Enzymology, Langhorne et al., eds., 73, pp. 3-46 [1981]).
In one preferred embodiment of the present invention, a hybridoma cell line is prepared as described above by fusing P3 X63-Ag86.5.3 mouse myeloma cell with an antibody-producing cell from the spleen of a BALB/c mouse which has been immunized with bovine La/SSB. This hybridoma cell line, designated as Lal, has been deposited with the American Type Culture Collection, Rockville, Md., and has been assigned accession number ATCC No. HB 8609. This deposit is available to the public upon the grant of a patent to the assignee. However, it should be understood that the availability of a deposit does not constitute a license to practice the invention in derogation of patent rights granted by governmental action.
Preferably, the antibody-producing hybridomas of the present invention are propagated in either of two ways. Hybridomas may be propagated in vivo by injecting a sample of the hybridoma into a histocompatible animal of the same species as the myeloma cell and the immunized animal described above. The animal so injected develops tumors which secrete specific moniclonal antibodies identical to those produced by the injected hybridoma. The monoclonal antibodies thus secreted collect in especially high concentrations in the serum and ascites fluid of the animal. Monoclonal antibodies against the selected autoimmune RNA protein may be recovered by extracting samples of these body fluids. Alternatively, selected hybridomas may be propagated in vitro in laboratory culture vessels from which the monoclonal antibodies against the selected autoimmune RNA protein can be harvested by decantation, filtration or centrifugation. This spent culture medium can then be used to purify the antibodies by established methods.
Preparation of Immunologically Active Fragments of Monoclonal Antibodies
When the monoclonal antibodies of the present invention are to be used in assaying methods, such as those involved in diagnostic and screening techniques, it is frequently desirable to use only an immunologically active fragment of the monoclonal antibody--that is an antibody fragment which binds to the antigen under study. Use of such immunologically active fragments reduces unwanted sample interactions and minimizes unwanted background in assay results.
Immunologically active fragments of the monoclonal antibodies of the present invention may be prepared by digestion of the monoclonal antibodies with an enzyme, such as pepsin. A particularly preferred fragment of the monoclonal antibodies of the present invention is the F(ab') 2 fragment which is preferably prepared by pepsin digestion of purified immunoglobulin obtained from hybridoma-induced ascites fluid prepared as described above. Digestion is preferably followed by gel filtration.
When methods involving the use of monoclonal antibodies are described in this disclosure, it should be understood that immunologically active fragments of these monoclonal bodies may be equivalently and interchangeably substituted for the monoclonal antibodies in these methods.
Detection of Antibodies Against the Selected Autoimmune RNA Protein in a Biological Sample
In accordance with the present invention, monoclonal antibodies produced as described above may be used to detect the presence in a biological sample of antibodies against a selected autoimmune RNA protein. The antibody detection method of the present invention is preferably practiced by use of monoclonal antibodies which are disposed in a reaction zone, which preferably comprises a protein-adsorbing surface such as that provided by a solid phase support such as a microtiter polystyrene plate, polystyrene tube or Sepharose beads. The monoclonal antibodies are preferably coated on the surface of the reaction zone, and held thereto in a fixed position. The coating step preferably is accomplished by incubating the monoclonal antibodies on the reaction zone surface for between about 2 and about 20 hours at between about 1° C. and about 24° C., higher temperatures being required for shorter incubation periods. More preferably, the monoclonal antibodies are incubated on the plates for about 16 hours (overnight) at about 4° C.
The unbound components from the monoclonal antibody containing medium preferably are removed next from the reaction zone. This removal is carried out so as to leave undisturbed the monoclonal antibodies which have been adsorbed on the surface of the reaction zone. This removal preferably is carried out by washing the reaction zone one or more times, preferably two times with an eluent to which the monoclonal antibodies are substantially inert. A preferred eluent is PBS-Tween, which is a preparation most preferably comprising 0.02M phosphate, 150 mM NaCl, 0.05% Tween (v/v) and 0.002% NaN 3 (w/v) at a pH between about 7.0 and 7.4.
The monoclonal antibodies disposed in the reaction zone are treated with an animal extract which contains the selected autoimmune RNA protein in an amount in stoichiometric excess of the quantity of monoclonal antibodies disposed in the reaction zone. The extract preferably is obtained from the animal spleen or thymus. Preferably the extract is from the same animal species as the selected autoimmune RNA protein used to generate the antibody-producing cells which were fused to form the hybridoma which generated the monoclonal antibodies. Thus, if bovine La/SSB was used to generate the antibody-producing cells used in the hybridoma, then the animal extract should preferably be bovine as well. It should be understood that the animal extract need not be characterized by any particular degree of protein purity, as long as an excess of the selected protein is present.
The contacting of the monoclonal antibodies with the animal extract is carried out under conditions permitting RNA protein-antibody binding between the selected autoimmune RNA protein in the extract and antibodies disposed in the reaction zone. The contacting step preferably is carried out by incubating the extract in the reaction zone. Preferably, the extract is incubated for a period of between about 2 hours and about 18 hours, at a temperature of between about 1° C. and about 24° C., higher temperatures being required for shorter incubation periods. Most preferably, the extract is incubated for about 16 hours at about 4° C. The contacting step results in binding of the excess autoimmune RNA protein to a substantial number of the monoclonal antibodies disposed in the reaction zone, resulting in formation of a reactive substrate in the reaction zone. This reactive substrate comprises a reactive source of autoimmune RNA protein, which is bound to the monoclonal antibodies, which in turn preferably have been adsorbed onto the surface of the reaction zone as described previously.
After the reactive substrate is formed, unbound components from the extract are next preferably removed from the reaction zone. This removal is preferably carried out so as to retain the reactive substrate in a substantially intact condition in the reaction zone. This removal of unbound extract components is preferably carried out by washing the reaction zone one or more times, preferably two times, with an eluent to which the reactive substrate is substantially inert. A preferred eluent is PBS-Tween.
After the unbound extract components have been removed from the reaction zone, the reactive substrate is next contacted with a biological sample in which the presence of antibodies to the selected autoimmune RNA protein, if any, is to be detected. When the method of the present invention is used to detect the presence of antibodies in an animal, such as a human, the biological sample preferably comprises an animal fluid in which the antibodies of interest are known or suspected to exist. In such an instance, the biological sample will most preferably comprise animal serum.
The biological sample is contacted with the reactive substrate under conditions permitting antibody-RNA protein binding between antibodies to the selected autoimmune RNA protein, if any, in the sample and the autoimmune RNA protein in the reactive substrate. The contacting step preferably is carried out by incubating the sample in the reaction zone for between about 2 hours and about 18 hours, at a temperature of between about 1° C. and about 24° C. Shorter incubation periods require higher temperatures. More preferably the sample is incubated in the reaction zone for about 16 hours at about 4° C. or 2 hours at 24° C. (room temperature). The contacting step results in binding of antibodies to the selected autoimmune RNA protein, if any, in the sample to the autoimmune RNA protein in the reactive substrate.
After the sample contacting step is completed, the presence of antibodies to the selected autoimmune RNA protein in the sample, if any, is determined by assaying for antibody-RNA protein reaction occurring in the reaction zone after the sample is contacted therewith. By comparing the results of such a sample assay with the results of the same assay conducted on an antibody standard, the presence of antibodies to the selected autoimmune RNA protein may be both detected and quantified.
The assaying step may be carried out by any suitable procedure for detecting the occurrence of antibody-RNA protein reaction, such as radioimmunoassay or immunofluorescence assay. Most preferably, however, the assaying step is carried out by an enzyme-linked immunoabsorbent assay (ELISA).
Once the sample contacting step is complete, the ELISA is preferably carried out by removing unbound sample components from the reaction zone, so as to retain the reactive substrate and any sample antibodies bound thereto in a substantially intact condition in the reaction zone. This removal of unbound sample components is preferably carried out by washing the reaction zone one or more times, preferably four times, with an eluent to which the reactive substrate and any sample antibodies bound thereto are substantially inert. A preferred eluent is PBS-Tween.
After unbound sample components have been removed from the reaction zone, the reaction zone next is contacted with an enzyme-labelled immunological conjugate to the antibody to be detected, in an amount in stoichiometric excess relationship to the amount of antibodies to be detected. The selection of an appropriate immunological conjugate will depend on the origin of the biological sample in which antibodies are to detected. Preferably, the conjugate comprises an enzyme conjugated to an immunoglobulin that will react (bind) with antibodies in the biological sample under study. When the biological sample is of human origin, the immunological conjugate preferably comprises goat anti-human immunoglobulin.
The immunological conjugate used in the preferred assay method utilized an enzyme, such as alkaline phosphatase or peroxidase, which is capable of degrading a reagent by a degradation process which is accompanied by a perceptible color change. Suitable degradable reagents include paranitrophenolphosphate when the selected enzyme is alkaline phosphatase, and o-phenylenediamine with hydrogen peroxide when the selected enzyme is peroxidase. It should be noted that where the enzyme utilized in the conjugate is peroxidase, the eluent used to wash the reaction zone, as described above, should not contain azide.
The contacting of the immunological conjugate is carried out under conditions permitting binding between sample antibodies bound to the reactive substrate and conjugate immunoglobulin. This contacting step is preferably carried out by incubating the immunological conjugate in the reaction zone, preferably for a period of between about 1 hour and about 18 hours, at a temperature of between about 1° C. and about 24° C. More preferably the conjugate is incubated in the reaction zone for about 16 hours at about 4° C. This contact results in binding of the immunoglobulin in the conjugate to substantially all of the sample antibodies which have bound to the reactive substrate. Thus, the extent to which the conjugate binds to the reactive substrate is directly proportional to the quantity of antibodies against the selected autoimmune RNA protein contained in the sample under study.
Unbound components of the enzyme-linked immunological conjugate next are removed from the reaction zone, so as to retain the sample antibodies and any immunological conjugate components bound thereto in substantially intact condition in the reaction zone. This removal of unbound immunological conjugate components preferably is carried out by washing the reaction zone one or more times, preferably four times, with an eluent to which the reactive substrate, any sample antibodies bound thereto, and any immunological conjugate components bound to sample antibodies, are substantially inert. A preferred eluent is PBS-Tween.
After the unbound immunological conjugate components have been removed from the reaction zone, the extent of conjugate binding to the sample antibodies is determined by contacting the degradable reagent with the immunological conjugate in the reaction zone. This contact permits a reaction between the enzyme of the conjugate and the degradable reagent which produces a perceptible color change in the reaction zone. The extent of color change caused by this reaction is preferably determined by measuring optical density of the reaction zone at the point of maximum adsorbance. If it is necessary or desirable to delay the measurement of optical density, the reaction may be arrested by adding an appropriate counter reagent, such as 2N NaOH, when the preferred absorbance is reached. By comparing the density measurement with the measurements obtained by conducting the same assay on antibody standards, the amount of antibodies in the sample can be quantified.
The above-described method of detecting antibodies to selected autoimmune RNA protein may be used to screen a subject, such as a human or other animal, for an autoimmune disorder characterizable by elevated levels of such antibodies. Two such autoimmune disorders in humans are systemic lupus erythematosus and Sjogren's syndrome, in which many patients experience elevated levels of La/SSB, Ro/SSA, nRNP or Sm. By testing a serum sample of a subject in accordance with the above-described method of antibody detection, the presence of elevated levels of one or more of these antibodies in a subject can be detected, as required for diagnosis or screening for such autoimmune conditions.
The above-described antibody-detection method may be advantageously practiced with a kit for use in assaying for antibodies against a selected autoimmune RNA protein. The kit comprises a first medium, such as a container, comprising monoclonal antibodies to the selected autoimmune RNA protein, and most preferably comprising an ELISA plate to which monoclonal antibodies to the selected autoimmune RNA protein have been affixed. The kit further comprises a second medium, such as a container, comprising an animal extract in which the selected autoimmune RNA protein is present in stoichiometric excess relationship to the quantity of monoclonal antibodies in the first medium. The kit further comprises a third medium, such as a container, comprising an enzyme-immunoglobulin conjugate reactive with the biological sample.
The kit preferably further comprises a fourth medium, such as a container, comprising a reagent degradable by the enzyme in the third medium, by a degradation process accompanied by a perceptible color change. Preferably the kit further comprises a fifth medium, such as a container, comprising a counter-reagent for stopping the enzyme-reagent degradation reaction.
Detection of a Selected Autoimmune RNA Protein in a Biological Sample
In accordance with the present invention, monoclonal antibodies produced as described above may be used to detect the presence in a biological sample of selected autoimmune RNA protein. The protein detection method of the present invention is preferably practiced by use of monoclonal antibodies which are disposed in a reaction zone, which preferably comprises a protein-adsorbing surface such as that provided by a solid phase support such as a microtiter polystyrene plate, polystyrene tube or Sepharose beads. The monoclonal antibodies preferably are coated on the surface of the reaction zone and adsorptively held thereto in a fixed position. The coating of the monoclonal antibodies on the surface of the reaction zone preferably is carried out by incubating the monoclonal antibodies on the solid phase support at between about 1° C. and about 24° C. for between about 2 hours and about 18 hours. More preferably, the monoclonal antibodies are incubated in the reaction zone at 4° C. for about 16 hours. The coating step results in the formation of a reactive substrate in the reaction zone which substrate preferably is fixed on the reaction zone surface.
The monoclonal antibodies which are not fixed on the surface of the reaction zone are removed from the reaction zone. The removal of the monoclonal antibodies not fixed on the surface of the reaction zone preferably is carried out by washing the reaction zone one or more times, preferably three times, with an eluent to which the monoclonal antibody coated surface of the reaction zone is substantially inert. A preferred eluent is PBS-Tween.
After the removal of the monoclonal antibodies which were not fixed on the reaction zone surface, the reactive substrate is contacted with a biological sample in which the presence of selected autoimmune RNA protein, if any, is to be detected. When the method of the present invention is used to detect the presence of RNA protein in an animal, such as a human, the biological sample preferably comprises an extract of animal tissue or animal fluid in which the protein of interest is known or suspected to exist. The method may also be adapted to permit detection of autoimmune RNA proteins produced by bacteria and other lower organisms governed by recombinant DNA technology.
The biological sample is contacted with the reaction substrate under conditions permitting antibody-RNA protein binding between the monoclonal antibodies as the reactive substrate and the selected autoimmune RNA protein, if any, in the biological sample. The contacting step preferably is carried out by incubating the sample in the reaction zone for between about 1 hour and about 18 hours, at a temperature of between about 1° C. and 24° C. More preferably, the sample is incubated in the reaction zone for about 16 hours at about 4° C. The step results in the binding of monoclonal antibodies in the reactive substrate to the selected autoimmune RNA protein, if any, in the sample.
After the sample contacting step is completed, the presence of selected autoimmune RNA protein in the sample, if any, is determined by assaying for antibody-RNA protein reaction occurring in the reaction zone after the sample in contacted therewith. By comparing the results of such a sample assay with the results of same assay conducted on a selected autoimmune RNA protein standard, the presence of the selected autoimmune RNA protein may be both detected and quantified.
The assaying step may be carried out by any suitable procedure for detecting the occurrence of antibody-RNA protein reaction, such as radioimmunoassay or immunofluorescence assay. Most preferably, however, the assay step is carried out by enzyme-linked immunoabsorbent assay (ELISA), by the same procedure described previously with reference to the detection of antibodies in a biological sample.
The above-described method of detecting a selected autoimmune RNA protein may be used in the study of diseases and disorders which involve the presence of such proteins. This protein detection method may be practiced with a kit for use in assaying for a selected autoimmune RNA protein. Preferably, the kit comprises a first medium, such as a container, comprising monoclonal antibodies to the selected autoimmune RNA protein, and, most preferably, an ELISA plate coated with monoclonal antibodies to the selected autoimmune RNA protein, and a second medium, such as a container comprising an enzyme-immunoglobulin conjugate reactive with the biological sample. The kit preferably further comprises a third medium, such as a container, comprising a reagent degradable by the enzyme in the second medium, by a degradation process accompanied by a perceptible color change. Preferably, the kit further comprises a fourth medium, such as a container, comprising a counter-regent for stopping the enzyme-reagent degradation reaction.
The following examples illustrate the practice of the methods of the present invention and the preparation and use of the compositions of the present invention.
EXAMPLE I
Purification of La/SSB
An affinity chromatography method was used to purify the La/SSB protein as described by Harley et al., (J. Rheumatol. 11, pp. 309-14 [1984]) and Akizuki et al. (J. Immunol. 119, pp. 932-38 [1977]). Calf thymus, bovine spleen and human spleen were extracted with an equal volume (wt:vol) of 2 mM dithiothreitol in phosphate buffered saline (PBS). The 60-80% (saturated) ammonium sulfate fraction was dialyzed against PBS and applied to an affinity column onto which was bound the IgG fraction of an SLE patient whose serum was known to have a particularly high concentration of anti-La/SSB IgG. The affinity column was made by coupling the purified IgG fraction from an SLE patient with anti-La/SSB precipitin to CNBr activated Sepharose 4B (Pharmacia Fine Chemicals, Piscataway, N.J.) by established methodology (Axen et al., Nature 214, pp. 1302-04 [1967]). La/SSB was eluted with 3M MgCl 2 at pH 7.0. The eluate was dialyzed and passed through a gel filtration column (Bio-Gel A-0.5 m, Bio-Rad Laboratories, Richmond, Calif.) in a tris buffer at pH 7.2.
The La/SSB fractions were analyzed for contamination by: (1) sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis (Laemmli, Nature 227, pp. 680-85 [1970]) using a silver stain (Merril et al., Science 211, pp. 1437-38 [1981]); (2) the Western blot technique (Towbin et al., Proc. Nat'l. Acad. Sci. USA 76, pp. 4350-54 [1979] and Burnette, Anal. Biochem. 112, pp. 195-302 [1981]); and, (3) an anti-La/SSB ELISA (Harley et al., J. Rheumatol., 11, pp. 309-14 [1984]).
Monospecific anti-Ro/SSA and anti-human immunoglobulin affinity column procedures were used to eliminate any contamination of the preparation with Ro/SSA and/or immunoglobulin. The fractions displaying antigenic activity were pooled, concentrated and stored at -70° C.
EXAMPLE II
Immunization of a Mouse With Purified La/SSB
To obtain cells capable of producing antibodies to bovine La/SSB, a Balb/c mouse was immunized with purified homogenous bovine La/SSB that was obtained as described in Example I. On day 1 the mouse received a subcutaneous injection containing 50 μg purified bovine La/SSB suspended in 200 μl of 0.02M Tris and 150 mM NaCl at pH 7.4 (TBS) in combination with 200 μl of Freund's Complete Adjuvant. On day 14 the mouse was boosted by an intraperitoneal injection of 10 μg purified bovine La/SSB suspended in 100 μl of TBS and 200 μl of Freund's Incomplete Adjuvant. Over the next four months the mouse was boosted seven times by intraperitoneal injections of 10 to 100 μg La/SSB, each dosage being suspended in between about 50 μl and about 200 μl TBS and administered without adjuvant. On each of the three days before spleen cells were removed, the mouse received booster injections of La/SSB. The first two of the boosts were administered intgraperitoneally and the final boost was administered to the tail vein.
EXAMPLE III
Production and Cloning of Hybridomas Producing Monoclonal Antibodies to La/SSB
Spleen cells of the mouse immunized according to the procedure in Example II were extracted by conventional methods. Murine myeloma fusion partner cells P3 X63-Ag86.5.3 were selected for fusion with the spleen cells.
The fusion of the spleen cells with the myeloma cells, the selective culturing of the resulting hybridoma cells and the cloning of antibody-producing hybridomas were performed in accordance with the procedures described by Galfre and Milstein (Methods of Enzymology, Langone et al., eds., 73, pp. 3-46 [1981]). The myeloma cells were mixed with the spleen cells in a HAT medium. A polyethylene glycol (PEG) solution was added to the mixture to promote fusion. After fusion had occurred, the action of the PEG was arrested by adding additional HAT medium to the mixture.
The fused cells next were selectively cultured by plating them out onto 24-well polystyrene plates. The wells of the plate contained a mixture of HAT medium and fetal calf serum (FCS) which is selective for the growth of hybridoma cells formed by fusion of myeloma cells with antibody-producing cells.
The wells demonstrating hybridoma growth were screened for the presence of antibodies against La/SSB protein by an enzyme-linked immunoabsorbent assay using a peroxidase-anti-mouse immunoglobulin conjugate. The hybridomas which were positive for antibody production and which survived and grew in the wells were single-cell cloned by plating them out into a 96-well plate. The wells of the plate contained a HAT and FCS mixture. The FCS used was Hybrisure (Hazelton-Dutchland). The hybridomas were allowed to colonize.
After colonization of the hybridomas had occurred, the wells were screened to detect which of the hybridomas were producing antibodies against La/SSB. Screening of the hybridomas for antibody production was carried out by the enzyme-linked immunoabsorbent assay (ELISA) technique (also using a peroxidase-anti-mouse immunoglobulin conjugate) of Engvall and Perlman (immunochemistry, 8, pp. 871-74 [1971]), which was modified as described by Harley et al. (J. Rheumatol., 11, pp. 309-14 [1984]). The ELISHA utilized affinity-purified bovine La/SSB and identified five wells containing antibody-producing hybridomas.
EXAMPLE IV
Characterization of Monoclonal Antibodies by Species Specificity Testing
Supernatant from three of the five wells which contained the antibody-producing hybridomas prepared as described in Example III was used to test for species specificity. Testing was carried out by separately incubating La/SSB from various animal species with final samples of each supernatant. The optical density of the resulting fluid mixture was measured with a Microelisa Reader MR580 (Dynatech, Alexandria, Va.) as an assay for antibody-La/SSB reaction.
The results of the tests are summarized in Table I. These results indicate that the antibody-binding activity of each of the three supernatants, when used at the appropriate dilution, was inhibited by extracts containing human or rabbit La/SSB.
Each of the three supernatants were subjected to the Western blot technique to determine if reactivity was actually with the La/SSB moiety or with a minor contaminant in the bovine La/SSB tissue extracts. The results of these tests disclosed that each of the three supernatants bound only the larger of the La/SSB peptides.
Stable clones were produced from only two of the three antibody-producing hybridomas. Based on the observation that antibodies produced by both of these clones bound only to the larger bovine La/SSB peptide, it was concluded that the antibodies produced by the two clones were otherwise similarly reactive. One of these two clones, taken from the well designated Well No. 2 in Table I, was selected for further investigation. This cell line, designated Lal, has been deposited with the American Type Culture Collection, Rockville, Md., and has been assigned accession number ATCC No. HB 8609.
TABLE I______________________________________Inhibition of Hybridoma Supernatant Anti-La/SSB BindingActivity by La/SSB from Different Sources (Expressed inOptical Density Units) Additions to Supernatant Fluid Phase crude crude 10% 20% 10% Calf Human Calf Human RabbitHybridoma Thymus Spleen Thymus Spleen ThymusSupernatant: None Extract Extract Extract Extract Extract______________________________________Experiment 1Well No. 1 1.107 0.473 1.122 0.341 1.249 1.249Well No. 2 1.101 0.954 1.245 0.548 1.395 1.322(Lal)Well No. 3 1.139 0.978 1.241 0.636 1.379 1.284Experiment 2Well No. 1 0.723 0.161 N.D.** 0.033 0.680 0.692[1:10]*Well No. 2 1.154 N.D. N.D. 0.207 1.166 1.199(Lal)[1:4]Well No. 3 1.059 0.462 N.D. 0.089 1.043 1.064[1:10]______________________________________ *Dilutions of hybridoma culture supernatants are expressed in ratio of number of parts of supernatant in the total number of parts of dilution. **N.D.: Not determined.
EXAMPLE V
Characterization of Monoclonal Antibodies by RNA Immunoprecipitation
In the course of characterizing the monoclonal antibodies against La/SSB, the ability of these antibodies to precipitate RNA from various sources was investigated. This analysis of RNA immunoprecipitation was conducted in accordance with the procedures described in Lerner et al., Proc. Natl. Acad. Sci. USA 76, pp. 5495-99 [1979] and Mimori et al., J. Biol. Chem. 259, pp. 560-65 [1984]. These procedures were as follows.
Phosphorus 32-labelled cell extracts of MDBK (bovine) and HeLa (human) cell lines were separately preincubated with Pansorbin (Calbiochem. Behrin, La Jolla, Calif.) in 150 mM sodium chloride, 50 mM Tris-HCl and 0.05% Nonidet P-40 at pH 7.5. The preincubated bovine and human cell extracts thus produced were used to test the RNA-precipitating properties of Lal antibodies, as follows.
Lal antibodies were covalently bound to cynogen bromide-activated Sepharose 4B (Pharmacia), pursuant to the manufacturer's instructions, and were incubated with goat anti-mouse IgG which was bound to protein A Sepharose. The bound monoclonal antibodies were separately incubated with 10 6 to 10 7 cells from each of the preincubated bovine and human cell extracts described above. After incubation was complete, the Sepharose was washed repeatedly. Its protein was denatured in SDS and sodium acetate, and RNA was extracted with phenol:chloroform:isoamyl alcohol mixture formulated in a 50:50:1 ratio. The RNA species in the ethanol precipitate were separated by 7M urea, 10% polyacrylamide gel electrophoresis, and were autoradiographed.
The preincubated bovine and human cell extracts described above also were used to test the RNA-precipitating properties of human serum known to contain anti-La/SSB precipitin. The serum was prepared for testing by adding 10 to 50 μl of serum to 2.5 mg. preswollen protein A Sepharose (Pharmacia). The serum-treated protein then was incubated separately with cell extracts as described above with reference to Lal-treated protein. RNA was likewise extracted and autoradiographed from the incubated protein as described above.
These studies revealed that Lal antibodies immunoprecipitated RNA only from the bovine cell extract, and not from the human cell extract. The human serum containing anti-La/SSB precipitin immunoprecipitated RNA from both the bovine cell extract and the human cell extract.
EXAMPLE VI
Characterization of Monoclonal Antibodies by Antinuclear Antibody Techniques
The species specificity of Lal monoclonal antibodies was further investigated by an antinuclear antibody (ANA) technique. Tissue substrates from four different species, rabbit, mouse, bovine and human were used in determining the presence of antinuclear antibodies. The SIRC rabbit corneal epithelial line (ATCC-CCL60), the NCTC clone of the 929 mouse fibroblast line (ATCC-CCL1), and the MDBK bovine kidney line (ATCC-CCL22) were grown on slides in RPMI 1640 with 50 g/ml gentamycin, 5 mM glutamine and 10% fetal calf serum. Human HEp-2 slides were purchased from Breit Laboratories, Inc., West Sacramento, Calif.
Two different antibody-containing test preparations were used to treat the tissue slides described above. The treated slides then were analyzed for presence of antinuclear antibodies. Standard techniques were used for the ANA determination with these substrates using goat anti-human fluoresceinated IgG (Breit) or goat anti-mouse fluoresceinated IgG (Sigma) as was appropriate for the source of antibody being studied.
The first test preparation was prepared from serum selected from an SLE patient. Each of the tissue substrates described above was reacted with the serum preparation, and each exhibited reactivity with substrates of tissue derived from all four species, namely human (HEp-2), bovine (MDBK), rabbit (SIRC) and mouse (NCTC 929).
The ANA reactivity of the human serum to substrates of each of the four species could be blocked by incubating the serum with 10 μg/ml bovine La/SSB.
The second test preparation was Lal hybridoma-induced ascites fluid. When treated with each of the tissue substrates described above, this preparation exhibited reactivity only with the bovine (MDBK) substrate. The results of these ANA studies are summarized in Table II.
The ANA reactivity of the Lal ascites fluid to the bovine substrate could be blocked by incubating the ascites fluid with 10 μg/ml bovine La/SSB.
TABLE II______________________________________Comparison of ANA Reactivity of SLE Serum and Lal-Induced Ascites Fluid To Various Animal Cell Lines(expressed in endpoint ANA titers) Tissue SubstrateAnti-La/SSB Human Bovine Rabbit MouseSource (HEp-2) (MDBK) (SIRC) (NCTC 929)______________________________________Human SLE 1:3200 1:3200 1:800 1:1600serumLal-induced <1:20 1:25,600 <1:20 <1:20ascites fluid______________________________________
The reaction between Lal ascites fluid and the bovine substrate produced a nuclear ANA pattern which resembled that produced by the reaction between the bovine substrate and the human serum containing anti-la/SSB antibodies.
EXAMPLE VII
Preparation of Ascites Fluid, IgG Purification, and F(ab') 2 Fragment Preparation
Ascites fluid was prepared by injecting pristine (Aldridge Chemical Company, Milwaukee, Wisc.) primed Balb/c mice with stable cloned Lal producing cells. Purified IgG was prepared from ascites fluid by treating the fluid with DE-52 (Watman Inc., Clifton, N.J.) or Affi-Gel Blue (Bio-Rad) column chromatography as described by Catalano et al. (J. Clin. Invest. 60, pp. 313-22 [1977]) and Brack et al. (J. Immunol. Methods 53, pp. 313-19 [1982]). Immunologically active F(ab') 2 fragments of the monoclonal antibodies in the purified IgG were generated by pepsin digestion of the IgG followed by Sephadex G100 (Pharmacia) gel filtration as described by Campbell et al. (Methods in Immunology, 2nd ed., W. A. Benjamin, ed., New York, N.Y., pp. 224-34 [1970]).
EXAMPLE VIII
Detection of Antibodies Against La/SSB in a Biological Sample
In order to measure the presence of antibodies against La/SSB in a biological sample, the enzyme-linked immunoabsorbent assay (ELISA) technique was modified to make use of Lal monoclonal antibodies. Microtiter plates were treated with a fluid medium containing an optimum of 10 g/ml of the purified Lal monoclonal antibodies. The fluid medium was allowed to remain on the plate for 16 hours (overnight) at 4° C. to allow the Lal antibodies to adhere to the surface of the plate. The unbound components are then removed and the plate is washed 2 times with PBS-Tween. The plate then was treated with a saturating concentration of La/SSB-containing bovine spleen extract from which Ro/SSA protein had been depleted by affinity chromatography. The spleen extract was incubated on the plate for 16 hours at 4° C. After washing the plate two times with PBS-Tween, a human serum sample, diluted to between about 1 part serum to about 100 to 10,000 parts diluent, was incubated on the plate for 16 hours at 4° C. The diluent used was PBS-Tween containing 0.1% bovine serum albumin. The plate was then washed again 4 times with PBS-Tween.
An enzyme conjugate of goat anti-human IgG and alkaline phosphatase (Sigma) was incubated on the plate for 16 hours at 4° C. A paranitrophenolphosphate substrate solution was applied to the plate, thereby causing a hydrolysis reaction to begin. The optical density of the plate was measured at 405 mM. By comparing this figure with optical densities produced by following the same procedure with standard quantities of antibodies, the presence of antibodies in the sample could be determined and the amount of such antibodies could be quantified.
The sensitivity of the above procedure was improved by using F(ab') 2 fragments prepared according to Example VII in lieu of the IgG Lal monoclonal antibodies.
EXAMPLE IX
Clinical Testing
Serum samples from 25 individuals, divided into groups according to medical diagnosis and presence or absence of Ro/SS and La/SSB precipitins, were assayed by an enzyme-linked immunoabsorbent assay (ELISA) using petrified La/SSB and by an ELISA using Lal antibodies prepared in accordance with the present invention. Each assay was performed on each sample numerous times. The results expressed in Table III below represent an average of selected multiple determinations from such assays.
Serum samples from ten normal individuals which tested negative for Ro/SSA and La/SSB by a precipitin test were assayed for antibodies against La/SSB first by an ELISA using purified bovine La/SSB prepared in accordance with Example I and then by an ELISA using Lal monoclonal antibodies in accordance with Example VII. The results of the two ELISAs show that all these samples displayed a lower reactivity in the ELISA using the Lal antibodies as shown in Section A of Table III.
Table III, Section B, summarizes the results of the two ELISAs on the serum samples from three patients diagnosed a having SS or SLE who tested positive for Ro/SSA and La/SSB by the precipitin test. These samples showed a response in an ELISA using the Lal antibodies which was comparable to the response obtained from an ELISA using purified La/SSB.
As is shown in Table III, Section C, the serum samples from five SLE or SS patients who tested positive for Ro/SSA and negative for La/SSB under the precipitin test and negative for La/SSB under the ELISA using purified La/SSB, only one did not have substantial reactivity above background in the ELISA using the Lal antibodies.
Three normal individuals who tested negative by precipitation for La/SSB and Ro/SSA but who tested positive under an Anti-La/SSB ELISA using purified La/SSB, were shown by the Lal ELISA using the Lal antibodies to have substantial levels of anti-La/SSB antibodies in their serum although these levels were significantly lower than those found by the ELISA using purified La/SSB. These results are shown in Section D of Table III.
Finally, as shown by Section E of Table III, a group of three SLE or SS patients who had tested positive for Ro/SSA and negative for La/SSB by precipitation and positive for La/SSB by an ELISHA using purified La/SSB, tested positive for anti-La/SSB antibodies under the ELISA using Lal antibodies but showed significantly higher antibody levels when the ELISA used Lal antibodies rather than purified La/SSB.
TABLE III______________________________________Results of Assays for Anti La/SSB Antibodiesin Normal and SLE/SS.sup.1 Patients.sup.2 PrecipitinDONOR SS or Ro/ La/ ELISA using ELISA usingNO. SLE SSA SSB purified La/SSB Lal antibodies______________________________________Section A1 no - - 224 522 no - - 175 293 no - - 69 324 no - - 443 425 no - - 79 236 no - - 683 267 no - - 29 1208 no - - 845 329 no - - 30 3310 no - - 444 112Section B11 yes + + 13,800,000 20,000,00012 yes + + 13,500,000 22,900,00013 yes + + 8,300,000 14,300,00014 yes + + 6,900,000 4,830,000Section C15 yes + - 158 23716 yes + - 409 91217 yes + - 120 20,40018 yes + - 640 3,02019 yes + - 120 1,260Section D20 no - - 7,200 19521 no - - 22,000 3,16022 no - - 21,000 1,820Section E23 yes + - 29,500 155,00024 yes + - 40,000 756,00025 yes + - 45,000 151,000______________________________________ .sup.1 SS = Sjogren's Syndrome; SLE = systemic lupus erthematosus. .sup.2 Results are expressed in units, one unit being the measure of reactivity present in 10.sup.-7 of a standard La/SSB precipitinpositive serum sample.
Changes may be made in the nature, composition, operation and arrangement of the various elements, steps and procedures described herein without departing from the spirit and scope of the invention as defined in the following claims. | Monoclonal antibodies against autoimmune RNA proteins such as La/SSB, Ro/SSA, nNP, and Sm. These monoclonal antibodies which are produced by a continuous hybridoma cell line, may be used in methods for detecting the presence of selected autoimmune RNA proteins and antibodies against such proteins in biological samples, and may be incorporated into diagnostic test kits for this purpose. The monoclonal antibodies may be applied in methods for screening subjects for systemic lupus erythematosus, subacute cutaneous erythematosus, neonatal lupus, Sjogren's syndrome, complete congential heart block, and other disorders which involve the presence of antibodies against autoimmune RNA proteins. | 8 |
RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional Patent Application No. 61/345,854, filed May 18, 2010.
COPYRIGHT NOTICE
[0002] ©2011 Aria Enterprises, Inc. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR §1.71(d).
TECHNICAL FIELD
[0003] This disclosure relates to furniture pieces and, in particular, to folding seats and tables each constructed with an articulated vertebral column that facilitates compact, convenient seat or table surface storage.
SUMMARY OF THE DISCLOSURE
[0004] A portable, compact folding furniture piece constructed as a seat or table is configured for convenient storage. The folding furniture piece comprises an object support assembly configured for operative connection to a mounting structure. The object support assembly includes an articulated vertebral column positioned between a support mount and a support base and a spring mechanism securing together as a flexible unit the support mount, vertebral column, and support base. The vertebral column includes multiple vertebral members. The spring mechanism exhibits flexibility properties such that the object support assembly assumes at rest an unfolded state and, in response to an externally applied bending force, assumes a folded state. In the unfolded state, the vertebral column is substantially straight to provide a closed support surface. In the folded state, the vertebral column is curved to provide a raised, open support surface on which an object can rest. Depending on the embodiment of the furniture piece, the object can be a person or thing.
[0005] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIGS. 1 and 2 are isometric views of a portable, compact folding seat, shown in, respectively, an unfolded state and a folded state, according to one embodiment.
[0007] FIGS. 3 , 4 , and 5 are, respectively, top plan, side elevation, and bottom plan views of the folding seat in the unfolded state shown in FIG. 1 .
[0008] FIG. 6 is an exploded view of the folding seat shown in FIG. 1 .
[0009] FIGS. 7A and 7B show the construction and operation of a seat assembly in, respectively, the unfolded state of FIG. 1 and the folded state of FIG. 2 .
[0010] FIGS. 8A , 8 B, and 8 C show, respectively, side elevation, top plan, and end views of a beveled vertebral slat for use in the seat assembly.
[0011] FIGS. 9A and 9B show, in its respective unfolded and folded states, the folding seat installed in a stadium or theater seating arrangement in which seats are installed on a stepped floor surface.
[0012] FIG. 9C shows the folding seat in its unfolded state of FIG. 9A and including a mounting member hinge-mounted to the seat back.
[0013] FIGS. 10A and 10B are isometric views of the folding seat of FIGS. 1 and 2 , configured in an alternative embodiment as a freestanding chair shown in, respectively, an unfolded state and a folded state.
[0014] FIGS. 11A and 11B are side elevation views of the freestanding chair of FIGS. 10A and 10B , respectively.
[0015] FIG. 12 is an exploded view of the freestanding chair of FIGS. 10A and 10B , showing modifications of a seat back foam layer and a seat assembly foam layer of the folding seat for accommodating chair leg sets to thereby form the freestanding chair.
[0016] FIG. 13 is a perspective view of the frontal portions of two side-by-side wall-mounted folding seats, the left-side seat shown in a folded state and the right-side seat shown in an unfolded state.
[0017] FIGS. 14A and 14B are side elevation views of the wall-mounted folding seat of FIG. 13 shown in, respectively, its unfolded state and its folded state.
[0018] FIG. 15 is a perspective view of the frontal portions of two side-by-side floor-mounted folding seats, the left-side seat shown in a folded state and the right-side seat shown in an unfolded state.
[0019] FIG. 16 is a perspective view of the frontal portions of two side-by-side wall-mounted folding tables, the left-side table shown in a folded state and the right-side table shown in an unfolded state.
[0020] FIGS. 17A and 17B are side elevation views of one wall-mounted folding table of FIG. 16 shown in, respectively, its unfolded state and its folded state.
[0021] FIGS. 18A and 18B and FIGS. 19A and 19B are pairs of isometric and end views showing a first alternative embodiment of a vertebral column in, respectively, a straightened, relaxed configuration corresponding to an unfolded state of a folding seat, and in a curved configuration corresponding to the folded state of a folding seat.
[0022] FIGS. 20A and 20B are respective isometric and end views showing one interior vertebral link of the first alternative embodiment of the vertebral column.
[0023] FIGS. 21A and 21B and FIGS. 22A and 22B are pairs of enlarged fragmentary respective isometric and end views showing in detail the interconnection of multiple vertebral links of the first alternative embodiment of the vertebral column in, respectively, the straightened configuration of FIGS. 18A and 18B , and in the curved configuration of FIGS. 19A and 19B .
[0024] FIGS. 23A and 23B and FIGS. 24A and 24B are pairs of isometric and end views showing a second alternative embodiment of a vertebral column in, respectively, a straightened, relaxed configuration corresponding to an unfolded state of a folding seat, and in a curved configuration corresponding to a folded state of a folding seat.
[0025] FIGS. 25A and 25B are respective isometric and end views showing one interior vertebral link of the second alternative embodiment of the vertebral column.
[0026] FIGS. 26A and 26B and FIGS. 27A and 27B are pairs of enlarged fragmentary respective isometric and end views showing in detail the interconnection of multiple vertebral links of the second alternative embodiment of the vertebral column in, respectively, the straightened configuration of FIGS. 23A and 23B , and in the curved configuration of FIGS. 24A and 24B .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] FIGS. 1 and 2 are isometric views of a portable, compact folding seat 10 , in a preferred embodiment shown in, respectively, an unfolded state and a folded state. FIGS. 3 , 4 , and 5 are, respectively, top plan, side elevation, and bottom plan views of folding seat 10 in the unfolded state shown in FIG. 1 .
[0028] With reference to FIGS. 1-5 , folding seat 10 comprises a generally rectangular seat back 12 that has a seat back rest surface 14 , a seat back mount surface 16 , a top end 18 , and a bottom end 20 . A first or seat back foam layer 22 is bonded with adhesive or Velcro™ fabric hook and loop fastener material to, and covers the surface area of, seat back rest surface 14 to provide a padded seat back 12 . A seat assembly 24 is positioned on seat back foam layer 22 and secured to seat back 12 near its bottom end 20 . Seat assembly 24 is of shorter length than that of seat back 12 . Seat assembly 24 includes a vertebral column 26 of nine lengthwise parallel-aligned beveled vertebral members or slats 28 b and corner vertebral members or slats 28 c of equal lengths positioned between a seat mount 36 and a seat base 38 . Beveled vertebral slats 28 b have beveled ends 30 b, and corner vertebral slats 28 c have right-angle corner ends 30 c. Vertebral column 26 is formed with a beveled vertebral slat 28 b at each end. Between the ends of vertebral column 26 is an alternating sequence of beveled vertebral slats 28 b and corner vertebral slats 28 c such that each corner vertebral slat 28 c is positioned between two beveled vertebral slats 28 b.
[0029] FIG. 6 is an exploded view of folding seat 10 ; FIGS. 7A and 7B show the construction and operation of seat assembly 24 in, respectively, the unfolded state of FIG. 1 and the folded state of FIG. 2 ; and FIGS. 8A , 8 B, and 8 C show several views of beveled vertebral slat 28 b marked with preferred dimensions. With reference to FIGS. 1 , 2 , 6 , 7 A, 7 B, 8 A, 8 B, and 8 C, first and second spaced-apart spring bands 40 and 42 secure together, as a flexible unit, seat mount 36 , vertebral column 26 , and seat base 38 , the last of which having a seat surface 44 . A second or seat assembly foam layer 46 covers the surface area of seat assembly 24 and forms an interface layer between seat assembly 24 and seat back foam layer 22 . Seat assembly foam layer 46 is bonded with adhesive or Velcro™ fabric hook and loop fastener material to seat base 38 , and the portion of seat assembly foam layer 46 covering seat surface 44 provides a padded seat for an occupant. Seat assembly 24 is secured to seat back 12 by four bolts 50 (only one shown) passing through axially aligned holes 52 in seat mount 36 , spacer blocks 54 set in aligned rectangular openings 56 in seat assembly foam layer 46 and seat back foam layer 22 ( FIG. 6 ), and seat back 12 in the manner described below with reference to FIG. 6 .
[0030] With particular reference to FIG. 6 , folding seat 10 is assembled by first joining the component parts of seat assembly 24 . This is accomplished by placing vertebral slats 28 b and 28 c alternately in lengthwise parallel alignment with their ends set even with one another to define for vertebral column 26 linear, discontinuous side margins along its length. Each of spring bands 40 and 42 has nine sets of two spaced-apart holes 60 that are located to receive screws 62 ( FIGS. 7A and 7B ) to hold vertebral slats 28 b and 28 c in the alignment configuration described above. Each of spring bands 40 and 42 has multiple sets of holes 64 through which screws 66 ( FIGS. 7A and 7B ) pass to secure the ends of spring bands 40 and 42 to seat mount 36 and seat base 38 to form seat assembly 24 as a flexible unit. The cross-sectional area of each of vertebral slats 28 b and 28 c defines a trapezoidal-shaped perimeter having nonparallel opposite sides of equal lengths. Each of the nonparallel sides is inclined at an 85.5° angle 70 ( FIG. 8C ) relative to the base of the trapezoid. Inclination angle 70 is set in cooperation with a 10° cant angle 72 ( FIGS. 9A and 9B ) of seat back 12 to establish a desired substantially horizontal, raised seat surface 44 for a seat occupant when folding seat 10 is in its folded state.
[0031] FIGS. 8A , 8 B, and 8 C show beveled vertebral slat 28 b marked with preferred dimensions (in millimeters) and formed with beveled ends 30 b. Corner vetebral slats 28 c are of the same dimensions as those of beveled vertebral slats 28 b, except that corner ends 30 c form right angles relative to the base of the trapezoid. The alternating sequence of beveled slats 28 and corner slats 28 c in vertebral column 26 prevents pinching of the seat occupant's fingers while folding seat 10 relaxes to its unfolded state.
[0032] With particular reference again to FIG. 6 , four rectangular openings 56 of each of seat back foam layer 22 and seat assembly foam layer 46 are arranged in a rectangular pattern to receive corresponding rectangular spacer blocks 54 of the same height as the combined thicknesses of seat back foam layer 22 and seat assembly foam layer 46 . Four bolts 50 pass through holes 52 in seat mount 36 , spacer blocks 54 , and seat back 12 to complete the assembly of folding seat 10 . Two spaced-apart rubber feet 74 are inserted in the bottom end of seat mount 36 to prevent excessive wear of folding seat 10 when it is dragged across the surface of a floor during transportation to and from storage.
[0033] FIGS. 9A and 9B show, in its respective unfolded and folded states, folding seat 10 installed in a stadium or theater seating arrangement in which seats are installed on a stepped floor surface 90 . A floor-contacting end 92 of folding seat 10 rests on a floor portion 94 , and seat back mount surface 16 of seat back 12 is mounted to a riser 96 . Skilled persons will appreciate that folding seat 10 can be installed in other tiered seating arrangements, such as, for example, in bleacher structures or on sloped floor surfaces.
[0034] With reference to FIGS. 4 , 5 , 9 A, 9 B, and 9 C, a mounting member 100 extends at a 10° angle 72 relative to seat back mount surface 16 to mount folding seat 10 to riser 96 with seat back 12 inclined at a 10° cant angle. Mounting member 100 is preferably set at a fixed 10° angle 72 . FIG. 9C shows a higher cost mounting alternative, in which mounting member 100 is hinge mounted to seat back 12 to permit mounting member 100 to pivot outwardly from a flush mount storage position in a recess (not shown) in seat back mount surface 16 to a 10° angle 72 operating position. Mounting member 100 has an L-shaped slot 102 with its longer segment 104 and its shorter segment 108 oriented, respectively, perpendicular and parallel to bottom end 20 of seat back 12 . Folding seat 10 can be dropped downwardly toward floor portion 94 such that longer segment 104 of slot 102 receives a mounting screw 108 anchored in riser 96 and then moved horizontally along shorter segment 106 of slot 102 to releasably lock folding seat 10 in place. FIG. 2 shows in seat back foam layer 22 and seat back 12 an access hole 112 through which a screwdriver can be inserted to turn mounting screw 108 passing through mounting member 100 and into riser 96 . FIG. 5 shows that longer segment 104 is offset from and the distal end of shorter segment 106 is aligned with a longitudinal center line 110 of seat back 12 so that, when folding seat 10 is locked in place, mounting screw 108 is positioned along center line 110 . FIG. 4 shows folding seat 10 with floor-contacting end 92 inclined at a 10° bevel angle 114 . Bevel angle 114 matches the 10° cant angle of seat back 12 and thereby causes folding seat 10 , when installed, to rest level on floor portion 94 . FIG. 9B shows folding seat 10 , when installed and in its folded state, with a substantially horizontal, raised seat surface 44 on which a seat occupant can sit.
[0035] With particular reference to FIG. 6 , FIGS. 7A and 7B , and FIGS. 9A and 9B , whenever no external force is applied to seat base 38 of seat assembly 24 , spring bands 40 and 42 cause folding seat 10 to automatically assume at rest its unfolded state ( FIGS. 7A and 9A ), in which vertebral column 26 is substantially straight. FIG. 6 shows small magnets 116 set in recesses 118 in seat surface 44 and in seat back rest surface 14 of seat base 38 and seat back 12 , respectively. Magnets 116 ensure that seat assembly 24 snaps shut and remains closed, i.e., seat mount 36 and seat base 38 lie in substantially the same plane, when folding seat 10 is unoccupied. Whenever a seat occupant pulls seat base 38 completely away from seat back 12 to present a raised, substantially horizontal sitting surface, folding seat 10 assumes its folded state ( FIGS. 7B and 9B ), in which vertebral column 26 is curved. Opening folding seat 10 applies to vertebral column 26 a bending force that closes the spaces between adjacent nonparallel sides of vertebral slats 28 b and 28 c and thereby squeezes adjacent vertebral slats 28 b and 28 c together to form a curved vertebral column 26 . The weight of an occupant sitting on foam padded seat base 38 maintains the folded state of folding seat 10 as it supports the seat occupant.
[0036] Preferred materials used in the construction of folding seat 10 include 13-ply baltic birch plywood for seat back 12 , vertebral slats 28 b and 28 c, seat mount 36 , and seat mount 38 ; spring steel for spring bands 40 and 42 ; and urethane foam material for seat back foam layer 22 and seat assembly foam layer 46 .
[0037] FIGS. 10A and 10B are isometric views of folding seat 10 , configured in an alternative embodiment as a freestanding chair 120 shown in, respectively, an unfolded state and a folded state. FIGS. 11A and 11B are side elevation views of freestanding chair 120 in, respectively, its unfolded state and its folded state. FIG. 12 is an exploded view of freestanding chair 120 , showing the addition of two similar chair leg sets 122 to and modifications of seat back foam layer 22 and seat assembly foam layer 46 of folding seat 10 to accommodate chair leg sets 122 and thereby form freestanding chair 120 .
[0038] With reference to FIGS. 10A , 10 B, 11 A, 11 B, and 12 , the component parts of folding seat 10 and freestanding chair 120 are the same, except for substitution of chair leg sets 122 for spacer blocks 54 and substitution of two slots 124 for different pairs of rectangular openings 56 . With particular reference to FIG. 12 , each of chair leg sets 122 has an upright portion 130 extending from and positioned at an 80° angle 132 relative to a floor support portion 134 . Upright portion 130 has the same height and width as the height and width of spacer blocks 54 and includes two holes 52 positioned so that bolts 50 pass through them during assembly of the chair. Rectangular openings 56 in seat back foam layer 22 and seat assembly foam layer 46 are replaced by slots 124 that extend into foam layers 22 and 46 from their respective bottom ends and cover a distance equal to the length of upright portions 130 . Upright portions 130 fit into slots 124 , and bolts 50 passing through holes 52 secure chair leg sets 122 in place to form freestanding chair 120 .
[0039] FIG. 13 is a perspective view of the frontal portions of two side-by-side wall-mounted folding seats 150 , one of which (left side) shown in a folded state and the other of which (right side) shown in an unfolded state. FIGS. 14A and 14B are side elevation views of wall-mounted folding seat 150 in, respectively, its unfolded state and its folded state. With reference to FIGS. 13 , 14 A, and 14 B, the component parts of folding seat 10 and wall-mounted folding seat 150 are the same, except for substitution of an inclined wall surface 152 as a common seat back of one or a row of multiple folding seats for a separate seat back 12 . Wall surface 152 is inclined at an 80° angle 154 relative to a floor 156 . Wall-mounted folding seat 150 is useful for installation in public transportation vehicles (e.g., subway car) or any other application in which compact, flat seat storage would be of benefit. When wall-mounted folding seat 150 is installed, seat back foam layer 22 rests against wall “I” surface 152 . Bolts 50 pass through holes 52 drilled at predetermined locations in wall surface 152 , as shown in FIG. 13 .
[0040] FIG. 15 is a perspective view of the frontal portions of two side-by-side floor-mounted folding seats 10 , one of which (left side) shown in a folded state and the other of which (right side) shown in an unfolded state. With reference to FIG. 15 , folding seats 10 are inclined at a 10° cant angle 72 in similar manner to that shown in FIGS. 9A and 9B and fastened to an inverted U-shaped railing 160 that is anchored to a floor 162 . Each of floor-mounted seats 10 can be secured to railing 160 by passing mounting screw 108 through mounting member 100 and a threaded hole (not shown) provided in the horizontal section of railing 160 .
[0041] FIG. 16 is a perspective view of the frontal portions of two side-by-side wall-mounted folding tables 170 , one of which (left side) shown in a folded state and the other of which (right side) shown in an unfolded state. FIGS. 17A and 17B are side elevation views of one wall-mounted folding table 170 in, respectively, its unfolded state and its folded state. With reference to FIGS. 16 , 17 A, and 17 B, the component parts of wall-mounted folding seat 150 and wall-mounted folding table 170 are the same, except for substitution of a flexible, uncushioned table (i.e., hard table top) surface layer 46 ′ for seat assembly foam layer 46 and a wall surface 172 as a mounting surface of folding table 170 for a separate seat back 12 and its corresponding seat back foam layer 22 . Wall surface 172 is oriented at a 90° angle relative to floor 156 , in a conventional arrangement. Wall-mounted folding table 170 is useful for installation in an office furniture system (e.g., a work space cubicle divider wall) or any other application in which compact, flat table storage would be of benefit. When wall-mounted folding table 170 is installed, table surface layer 46 ′ rests against wall surface 172 . Bolts 50 pass through holes 52 drilled at predetermined locations in wall surface 172 , as shown in FIG. 16 . Wall-mounted folding table 170 can be constructed to remain in the folded state while supporting no or a light-weight object by use of a heavy weight or weighted table base 38 or by selection for spring bands 40 and 42 a material having a sufficiently low spring constant. Magnets 116 could be used to keep wall-mounted folding table 170 in the unfolded state.
[0042] FIGS. 18A and 18B and FIGS. 19A and 19B are pairs of isometric and end views of a vertebral column 190 , which constitutes a first alternative embodiment of a vertebral column assembled with individual vertebral links interconnected by web sections confining expansion foam slats to form an integral distributed spring mechanism. FIGS. 18A and 18B show vertebral column 190 in a straightened, relaxed configuration, and FIGS. 19A and 19B show vertebral column 190 in a curved configuration assumed in response to an externally applied bending force. With reference to FIGS. 18A , 18 B, 19 A, and 19 B, vertebral column 190 includes nine parallel-aligned vertebral links, seven of which are interior vertebral links 192 of nominally the same size and shape and two of which are end-coupling vertebral links 194 and 196 . End-coupling vertebral links 194 and 196 are of the same size and shape of interior vertebral links 192 , except for formation of the respective U-shaped free ends 198 and 200 sized to receive different ones of seat mount 36 and seat (or table) base 38 . Each interior vertebral link 192 has on opposite sides and extending along its length two sets of complementary structures configured to interlock with corresponding complementary structures of next adjacent vertebral links 192 . End-coupling vertebral links 194 and 196 have on the sides opposite their respective free ends 198 and 200 structures configured to interlock with corresponding complementary structures of the next adjacent interior vertebral links 192 . The entire assembly of nine vertebral links forms articulating adjoining vertebral links.
[0043] FIGS. 20A and 20B are respective isometric and end views of one interior vertebral link 192 , which is of I-beam shape with different structural features at its four lateral ends. Interior vertebral link 192 has on a seat side member 204 a first set of interlocking structures including an open-end hinge sleeve 206 and a pivot 208 and on an underside member 210 a second set of interlocking structures including a hooked end 212 and a rolled edge 214 . A web 216 interconnects seat side member 204 and underside member 210 . FIGS. 18A and 18B show end-coupling vertebral link 194 , on its seat side member 204 , open-end hinge sleeve 206 of the first set and, on its underside member 210 , hook and 212 of the second set. FIGS. 18A and 18B also show end-coupling vertebral link 196 , on its seat side member 204 , pivot 208 of the first set and, on its underside member 210 , rolled edge 214 of the second set. Vertebral links 192 , 194 , and 196 are preferably made of extruded aluminum.
[0044] FIGS. 21A and 21B and FIGS. 22A and 22B are pairs of enlarged fragmentary isometric and end views showing in detail the interconnection of multiple vertebral links to form vertebral column 190 of articulating adjoining vertebral links 192 and 196 . Each pair of adjacent vertebral links is pivotally joined by engagement of pivot 208 in hinge sleeve 206 and by compression of rolled edge 214 against hooked end 212 by an expansion foam or elastomeric slat 220 positioned between and contacting hooked end 212 and web 216 . Elastomeric slat 220 is preferably made of polyurethane foam of appropriate durometer and is of rectangular cross-sectional shape when at rest, i.e., before insertion between hooked end 212 and web 216 of adjacent vertebral links. Hinge sleeves 206 and pivots 208 arranged in alternating succession and each adjacent hinge sleeve 206 and pivot 208 connected to each other constitute interlocking articulating structures of vertical column 190 that establish its curvature. FIGS. 21A and 21B show vertebral column 190 in a straightened configuration corresponding to the unfolded state of folding seat 10 , and FIGS. 22A and 22B show vertebral column 190 in a curved configuration corresponding to the folded state of folding seat 10 .
[0045] FIGS. 21B and 22B show elastomeric slats 220 exhibiting deformed, concave surfaces 222 that function as bearing surfaces against which hook ends 212 rest. Concave surfaces 222 change shape in response to changing compressive forces imparted by hook ends 212 so as to permit them to remain in place while complying with the different amounts of curvature of vertebral column 190 as it bends between the unfolding and folding states of folding seat 10 . Elastomeric slats 220 urge vertebral column 190 to its straightened configuration by inherent restorative forces of elastomeric slats 220 urging their return to a nominal rectangular shape in the absence of externally applied compressive forces during unfolding of folding seat 10 . If vertebral column 190 is used in the construction of wall-mounted table 170 , elastomeric slats 220 may be formed of softer (i.e., lower durometer) material to decrease its resistance to deformation and thereby cause wall-mounted table 170 to remain in the folded state when no object rests on the table surface.
[0046] FIG. 21B shows the vertebral link dimensions and separation distances of adjoining vertebral links that establish for vertebral column 190 the progressive incremental angular displacements of pivots 208 interlocked within their associated hinge sleeves 206 to achieve the straightened configuration shown in FIG. 18B (unfolded state of folding seat 10 ) and the curved configuration of FIG. 19B (folded state of folding seat 10 ). With reference to FIG. 21B , hooked end 212 and rolled edge 214 interlocked in the straightened configuration are separated by a distance 224 of 2.59 mm. A center-to-center distance 226 of open-end hinge sleeve 206 and pivot 208 of the first set of interlocking structures on underside member 210 of each interior vertebral link 192 is 19.7 mm. The width of vertebral column 190 is a distance 228 of 19.7 mm between the outer surfaces of seat side member 204 and underside member 210 of each of vertebral links 192 , 194 , and 196 . FIG. 22B shows the complete closure of separation distance 224 and resulting contact between interlocked hooked end 212 and rolled edge 214 in the folded state of folding seat 10 .
[0047] FIGS. 23A and 23B and FIGS. 24A and 24B are pairs of isometric and end views of a vertebral column 190 ′, which constitutes a second alternative embodiment of a vertebral column assembled with individual vertebral links interconnected by web sections confining expansion foam slats to form an integral distributed spring mechanism. The component parts of vertebral column 190 and vertebral column 190 ′ are the same, except for a modification of one of the first set of interlocking structures that decouples them and substitution of a larger rectangular elastomeric slat 220 ′ that fits between webs 216 of adjacent vertebral links. The views of vertebral column 190 and its components shown in FIGS. 18A and 18B , FIGS. 19A and 19B , FIGS. 20A and 20B , FIGS. 21A and 21B , and FIGS. 22A and 22B correspond to the views of vertebral column 190 ′ and its components shown in the respective FIGS. 23A and 23B , FIGS. 24A and 24B , FIGS. 25A and 25B , FIGS. 26A and 26B , and FIGS. 27A and 27B . Similar components and structural features are identified by common reference numerals, and corresponding, modified components and features are identified by the same reference numerals followed by primes.
[0048] The modification of the first set of interlocking structures entails substitution of a rolled edges 212 ′ of vertebral links 192 ′ and 194 ′ for hooked ends 212 of vertebral links 192 and 194 . The substitution of rolled edge 212 ′ in each vertebral link 192 ′ and 194 ′ results in a decoupling of adjacent rolled edges 212 ′ and 214 of vertebral column 190 ′, as shown in FIG. 23B . Rectangular elastomeric slat 220 ′ is sized to form a tight fit between webs 216 of adjacent ones of vertebral links 192 ′, 194 ′, and 196 ′, as shown in FIGS. 23B and 26B . FIGS. 24B and 27B show that elastomeric slat 220 ′ undergoes compression on all sides in response to changing compressive forces imparted by different amounts of curvature of vertebral column 190 ′ as it bends between the unfolding and folding states of folding seat 10 .
[0049] FIG. 26B shows the vertebral link dimensions and separation distances of adjoining vertebral links that establish for vertebral column 190 ′ the progressive incremental angular displacements of pivots 208 interlocked within their associated hinge sleeves 206 to achieve the straightened configuration shown in FIG. 23B (unfolded state of folding seat 10 ) and the curved configuration of FIG. 24B (folded state of folding seat 10 ). With reference to FIG. 26B , adjacent rolled edges 212 ′ and 214 in the straightened configuration are separated by a distance 224 ′ of 2 . 59 mm. A center-to-center distance 226 of open-end hinge sleeve 26 and pivot 208 of the first set of interlocking structures on underside member 210 of each interior vertebral link 192 is 19.7 mm. The width of vertebral column 190 ′ is a distance 228 of 19.7 mm between the outer surfaces of seat side member 204 and underside member 210 of each of vertebral links 192 ′, 194 ′, and 196 ′. FIG. 27B shows the complete closure of separation distance 224 ′ and resulting contact between adjacent rolled edges 212 ′ and 214 in the folded state of folding seat 10 . FIGS. 24B and 27B show the convergence of adjacent rolled edges 212 ′ and 214 of vertebral column 190 ′ bent in the folded state of folding seat 10 .
[0050] End-coupling vertebral links 194 and 196 at opposite ends of vertebral column 190 and end-coupling vertebral links 194 ′ and 196 ′ at opposite ends of vertebral column 190 ′ each receive fasteners (not shown) to attach one of the end- coupling vertebral links to seat mount 36 and the opposite one of the end-coupling vertebral links to seat base 38 to form complete seat assemblies 24 .
[0051] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. For example, substitution of a single, wide spring band for spring bands 40 and 42 may be acceptable in certain configurations of folding seat 10 . The scope of the present invention should, therefore, be determined only by the following claims. | A portable, compact folding furniture piece ( 10 ) constructed as a seat or table is configured for convenient storage. The folding furniture piece comprises an object support assembly ( 24 ) that is configured for operative connection to a mounting structure ( 12 ) and includes a spring mechanism ( 40, 42 ) securing together as a flexible unit a support mount ( 36 ), an articulated vertebral column ( 26 ), and a support base ( 38 ). The spring mechanism exhibits flexibility properties such that the object support assembly assumes at rest an unfolded state and, in response to an externally applied bending force, assumes a folded state. In the unfolded state, the vertebral column is substantially straight to provide a closed support surface ( 44 ). In the folded state, the vertebral column is curved to provide a raised, open support surface on which an object can rest. Depending on the embodiment of the furniture piece, the object can be a person or thing | 4 |
BACKGROUND OF INVENTION
The present invention relates in general to polymer-lithographic processes. Specifically, the present invention is concerned with a process for the fabrication of sub-wavelength structures.
In semiconductor technology and in microelectronics, the dimensions of structures are becoming smaller and smaller. In memory production today, e.g., structures with a width of less than 400 nm are produced using optical lithography in combination with the masking technique. Photholithographic processes are vital steps in the fabrication of, e.g., semiconductor devices. In a photolithographic process, an exposure light, usually ultraviolet (UV) light is used to expose a photoresist-coated semiconductor wafer through a mask (in the following called photomask). The purpose of the photolithographic process is to transfer a set of patterns representative of the circuit layer onto the wafer. The patterns on the photomask define the positions, shapes and sizes of various circuit elements such as diffusion areas, metal contacts and metallization layers, on the wafer.
In optical lithography a limit can be expected at approximately 150 nm because of diffraction effects.
However, structures with even smaller dimensions are required for new applications such as single-electron transistors or molecular electronic components. In the case of very high-frequency circuits this is also true in conventional electronics. There is also a need to reduce, e.g., the read and write dimensions in thin film magnetic heads. In addition to that, micro structures having a very high aspect ratio of about 5 to 30 and greater will be needed.
The resolution of conventional optical lithography schemes is mainly limited by the wavelength of the light used for the transfer of a mask pattern onto a resist. The wavelength of the exposing radiation is a main determinant of pattern resolution W, given by the Rayleigh equation , where l is the wavelength of the exposing light, NA is the numerical aperture of the optical lithography tool, and k1 is a constant for a specific lithography process. In other words, the resolution W is proportional to the wavelength l of the exposing light. Cutting-edge production today creates features that are 130 nm wide, using 248 nm illumination. Currently, the implementing schemes based on light are the bottleneck when trying to obtain structures of a feature size below 100 nm. State-of-the-art optical lithography systems for making current DRAMs, for example, are quite expensive. Alternative processes become attractive when moving on to smaller feature sizes, but the required investments are huge. Thus, techniques that maintain compatibility with existing processes are inherently valuable.
One well-known form of optical lithography is the so-called hard-contact lithography, where a mask is put directly into contact with a substrate to be patterned. Features on the mask, comprising alternatively translucent and opaque regions in a well-defined pattern, are transferred into a photoresist in a 1:1 relation to their dimensions on the mask. Hard-contact lithography can, in principle, make structures with sizes below the wavelength of illumination, but the contact used to place the mask on the substrate compromises the integrity of the process as the possibility of confounding material on the surface of the mask and mask damage greatly limit the useful number of times the mask can be used. Cost is particularly worrisome as the feature scale shrinks and the expense of mask fabrication skyrockets with the increase in the density of its features. Contact masks are also generally much more expensive than those used in optical-projection lithography since for an equivalent resolution the critical dimensions in the former need to be smaller than those in the latter, by the reduction factor used in a projection system. Dust particles and other physical impediments to the substrate are catastrophic in hard-contact lithography as they lift the mask away from the surface, blurring the pattern. Such defects appear over an area much larger than the obscuring particle because the mask is unable to conform around their presence; this problem is compounded as the feature scale shrinks such that even a 200 nm particle can be harmful. In addition, the resist can get stuck to the mask. Hard-contact lithography has thus not found a significant role in manufacturing of small-scale integrated circuits.
There are many approaches known, that improve conventional lithography systems in that filters, projection lenses, or appropriately modified masks are employed. These approaches become increasingly complicated and expensive with reduced feature scale. One example is the so-called optical-projection lithography. The optical lithography based on projection is a very successful and widely employed means of making features down to 200 nm. Here, a pattern of intensity variations in the far field results when light is shone through a mask like that used in contact lithography. The light propagates through air and is focused by a lens to create an image of the desired pattern on a resist-covered substrate, often demagnified by a factor of 5–10 from its size on the mask. Projection lithography is largely limited to features sizes equal or larger than the wavelength I of light. Its implementation becomes increasingly difficult as the scale shrinks towards and below 200 nm, where very complicated systems of lenses and materials are required to carry out existing and proposed schemes. The area over which uniform illumination can be achieved is particularly problematic The maximum current field size with the best 248-nmexposure tool is now only 30×30 mm.
It is generally a disadvantage of most of these approaches that they are getting more and more complicated and expensive when trying to obtain smaller feature sizes. Furthermore, there is a tradeoff between maximum resolution, depth of focus and achievable field image which comes from the use of a lens to focus the light.
European Patent Office publication EP-A-1 001 311 proposes a patterning device with which incident light is guidable at least partially to at least one cover element which is in contact with the patterning device. The cover element comprises light-sensitive material and is arranged on top of a substrate protrusion element on a surface of a substrate and/or is itself structured on a substrate.
Though many approaches have been made to arrive at critical dimensions by using conventional lithography systems, there is still a need for uncomplicated and low-cost methods for small feature generation.
On the other hand, printing from a patterned surface to thin layers of material is a well known and well documented process in printing industry.
Printing processes were originally developed for the exchange and storage of information adapted to human vision. This field of application requires pattern and overlay accuracies down to 20 μm for high-quality reproduction. In a few cases, printing processes have been used for technological patterning, e.g., gravure offset printing was used to make 50-μm-wide conductor lines on ceramic substrates, and to pattern thin-film transistors for low-cost displays. Offset printing was used for the fabrication of capacitors and printed and plated metal lines as narrow as 25 μm. Finally, printed circuit boards and integrated circuit packaging are popular applications of screen printing in the electronics industry. (B. Michel et al., IBM J. Res. Develop. 45, 697 (2001) and references therein).
In a process known as flexography, viscous ink is printed onto porous paper and permeable plastic. Flexography is a direct rotary printing method that uses resilient relief image plates of rubber or other resilient materials including photopolymers to print an image on diverse types of materials that are typically difficult to image with traditional offset or gravure processes, such as cardboard, plastic films and virtually any type of substrate whether absorbent or non-absorbent. As such it has found great applications and market potential in the packaging industry. Usually, the viscous ink prevents a direct contact of the stamp with the substrate because it cannot be displaced quickly enough during the fast printing operations. The transfer of a thick layer of ink is desired in this typical mode of operation but also prevents replication of laterally small features—this is the main reason why printed feature sizes cannot be smaller than 20 μm. Printing onto metal foils has been implemented in a few applications but is much more difficult than other processes (H. Kipphan, “Handbuch der Printmedien”, Springer Berlin, 2000 and J. M. Adams, D. D. Faux, and J. J. Rieber, “Printing Technology 4th Ed.”, Delamare Publishers, Albany, N.Y.).
Microcontact printing uses a similar stamp as flexography does, but typically transfers a monolayer of ink onto an impermeable metal surface. A more general process now called soft lithography is successfully applied in different variants to print thiols and other chemicals to a wide variety of surfaces. Typically, the chemicals are first applied to the patterned stamp surface as solutions in a volatile solvent or using a contact inker pad. After inking and drying, the molecules are present in the bulk and on the surface of the stamp in a “dry” state and are transferred to the surface by a mechanical contact. Reasons for the choice of poly-(dimethyl)siloxane (PDMS) as the stamp material are its good rubber-like elasticity, a chemistry similar to glass, the possibility to buffer ink molecules, and (very important) its excellent gas permeability that enables small amounts of air to dissolve into or escape through the stamp matrix. (see B. Michel et al. “Printing meets lithography”, IBM, J. Res. Develop. 45 (5), 697 (2001)).
There remains a need for a method for the manufacture of sub-wavelength structures that are not diffraction restricted, and particularly for structures having increased aspect ratios, so that existing critical dimensions may be narrowed still further.
SUMMARY OF INVENTION
The present invention addresses the above-described need by providing a method for the manufacture of sub-wavelength structures on a substrate. In accordance with the present invention, this is done by providing a deformable photoresist on the substrate, and forming a hydrophilic stamp (made of a material having a higher refractive index than the photoresist) carrying wave guiding structures. The wave guiding structures are then imprinted into the deformable photoresist by bringing the stamp and the substrate in close contact. Light is coupled into the wave guiding structures to create evanescent waves to expose the photoresist; the photoresisist is then developed. The photoresist may be either positive or negative photoresist. The wave guiding structures may be formed by a mask production method or alternatively by a replica method from a precursor. An example of material for the stamp is poly-(dimethyl)siloxane. The coupling of the light may be performed using a grating structure, a prism structure or via optical fiber connectors. The stamp may advantageously be covered with a metal layer such as chromium. The size of the sub-wavelength structures can be varied in accordance with the material of the stamp and/or the photoresist, or in accordance with a wavelength of light used to expose the photoresist. The critical dimensions of said the sub-wavelength structures may depend on an entrance depth of the evanescent waves.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A to 1D schematically depict the process steps according to a first embodiment of the invention when using a positive photo resist.
FIGS. 2A to 2D schematically show the process steps according to a second embodiment of the invention when using a negative photo resist.
DETAILED DESCRIPTION
A preferred embodiment of the invention involves a combination of integrated optics, using waveguide structures and imprinting techniques, using elastomeric stamps.
Imprinting is able to resolve small structures below 100 nm for moderate aspect ratios and resist thickness. For a given structure produced by stamping, the dimension can be further reduced and the aspect ratio increased by curing or exposing the imprinted pre-polymer through the stamp integrated optics structure.
The method lowers the necessary preconditions for the fabrication of the stamp structures. This is similar to processes like Ion Beam Trimming or Slimming and provides a substantially smaller photo structure. Aspect ratios are accordingly increased.
The stamp is fabricated by standard methods like electron beam lithography and dry etching into a material able to support exposure by UV-light, e.g., quartz and SiN but with a higher refractive index than the polymer used, e.g., cross-linked polymer or poly-(dimethyl)siloxane to allow conditions of total internal reflection needed to support guided modes. The stamp is structured in a way that wave guiding structures are formed either directly, using mask production methods such as e-beam exposure and etching into the material, or by using a replica method from a precursor. Coupling of light into the wave guiding structures is done with grating- or prism-like structures or via optical fiber connectors to feed light from an external source into an optical fiber and then into the wave guiding structures on the stamp. The mask is covered with a layer of metal, e.g., chromium, on all horizontal surfaces. Light is trapped within the wave guiding structures and depending on the geometry and material composition waveguide modes are established which are mostly confined to the core of the waveguide but to a certain amount extend into the surrounding photosensitive material. It is important that there are no propagating but only evanescent waves outside the mask material. Propagation of light is only taking place in the core of the waveguide.
FIG. 1A schematically shows how the pre-structure formed on the stamp 10 is imprinted into a photoresistive material (photoresist) 12 formed on the substrate 14 to be processed. The substrate material 14 to be stamped is covered by the photoresistive material 12 which is able to be deformed by stamping. As shown in FIG. 1A , the stamp 10 and the substrate material 14 are brought in close contact and the photoresistive material 12 is displaced. Therefore, the photoresistive material 12 is structured as a replica of the stamp structure. As can be seen in FIG. 1A , the wave guiding structures 16 formed on the stamp 10 will thus immerse into the light-sensitive material, i.e., the photoresistive material 12 , and a region of a critical dimension 30 is formed. As has already been mentioned, the stamp is covered with a metal layer 18 , e.g., chromium, on all horizontal surfaces not to allow direct exposure on the photoresisitive material in the case when the light incoupling is done with grating- or prism-like structures. It can also be advantageous to cover the whole stamp including the wave guiding structures only leaving open the areas especially used for incoupling of light established with grating- or prism-like structures.
Next, the wave guiding structures 16 within the stamp 10 are fed by the coupling mechanism within the stamp, i.e., the grating or prism like structures, with the appropriate wavelength for the exposure of the photosensitive material 12 . On the interfaces between the stamp material and the photosensitive material 12 evanescent waves will expose the photosensitive material 12 , leaving exposed areas 20 ( FIG. 1B ).
In the next step, the stamp is removed from the substrate and the photoresist material, leaving the structure shown in FIG. 1C .
In the case of a positive photoresist 12 , the exposed areas will be developed away leaving a resist line 22 between the regions cleared from photoresist by stamping the two adjacent wave guiding structures into the photoresist. This resist line will be smaller than the stamped resist line, i.e., the region of critical dimension 30 , by the distance exposed by the evanescent waves established ( FIG. 1D ). Thus, by using evenescent waves produced by the waveguide structures 16 , the structures present at the beginning of the process according to the invention ( FIG. 1A ) can be further narrowed ( FIG. 1D ).
FIGS. 2A to 2D depict the conditions when using a negative photoresistive material 24 . As can be seen, the first steps ( FIGS. 1A to 1C ) are identical to the steps performed using the positive photoresistive material 12 . However, in case of a negative resist 24 on both sides of a wave guide 16 , lines 26 are formed that have a critical dimension according to the entrance depth of the evanescent waves. The entrance depth is given by the refractive index difference between the stamp and the photoresistive material and the absorbtive properties as well as the developing characteristic of the photoresistive material. The neighboring lines 28 formed between the two waveguides 16 form a space between resist structures that is to be made arbitrary small. Thus, structures can be produced that are not diffraction restricted.
While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention and the following claims. | A method for the manufacture of sub-wavelength structures on substrates is provided, wherein a deformable photoresist is arranged on a substrate. A hydrophilic stamp (made of a material having a higher refractive index than the photoresist) is used to imprint wave guiding structures into the deformable photoresist. Light is coupled into the wave guiding structures to create evanescent waves to expose the photoresist. By imprinting critical dimensions on the substrate and subsequently exposing the resist by means of optical structures integrated in the stamp, those critical dimensions can be further reduced. | 1 |
The present invention relates to heat transfer apparatus and more particularly to such apparatus which recovers flue gas exhaust heat and employs it to enhance operation of an associated appliance. More particularly still, the present invention relates to such apparatus which recovers flue gas heat from a plurality of appliances and applies it to enhance operation of one of the appliances.
BACKGROUND OF THE INVENTION
A well recognized shortcoming of most home heating systems is their relatively low level of efficiency. Furnaces which burn combustible mixtures, particularly hydrocarbon fuels and atmosphere oxygen, require exhaust flues to externally vent the products of combustion to assure that carbon monoxide and other toxic gases do not accumulate in the home to present a health or safety hazard. Studies have indicated that a significant percentage of the heat from home furnaces is lost through the escape of hot flue gases up the chimney. Other home appliances, particularly hot water heaters, which are fueled by combustible mixtures also lose substantial amounts of thermal energy in the venting of hot exhaust gases.
One prior art approach has been to install thermally actuated valves or dampers within the flues which are carefully calibrated to open at a relatively high temperature which is achieved only when the furnace is in actual operation. Such valves open to allow normal aspiration while the furnace is running and partially close to restrict exhaust gas flow when the furnace is off. Even in the off mode, however, flue dampers must remain open a sufficient amount to permit escape of exhaust gas generated by the furnace pilot light, and therefore, provide a thermal leak. Such devices have been only partially successful in the marketplace inasmuch as they could present a safety hazard under some failure modes. Additionally, and more importantly, such devices only operate to block or prevent the escape of heat during periods in which the furnace is not operating. This heat represents a relatively small portion of the total heat loss through the flue during the overall furnace duty cycle of operation.
Other prior art approaches to capturing some of the heat lost up the flue have suggested the application of heat exchangers, positioned within the flue, which circulate a heat absorbing liquid (water) therethrough. The heated water is then either returned directly to the hot water tank of the home as a supplement to normal hot water generation or is used in a hot water radiator to provide supplemental heat. Although such prior art systems are partially successful in capturing some of the otherwise lost heat of the furnace, they have been employed primarily in hot water heating systems as opposed to forced air heating systems and have been relatively complex and expensive, both in installation and maintenance.
A number of prior art devices employed in forced air type heating systems for building have also recognized the advantage of recovering heat from escaping hot flue gases, and have attempted to devise means for transferring a portion of the heat of the exhausted gas to the area intended to be heated. Such heating systems typically include a heating chamber or furnace provided with a warm air delivery duct and a cool air intake or return. A flue pipe for venting the gases and products of combustion is in communication with the heating chamber. The flue pipe, which normally includes a metallic, heat conducting material, passes through the cool air return duct so that the cool air returning to the heating chamber passes over warm surfaces of a short stretch of the flue pipe. The returning cool air is, in effect, slightly preheated prior to entering the heating chamber. In this manner, the temperature of the air within the heating chamber to be heated is slightly increased. Consequently, the energy required to elevate the temperature of the preheated return air to the desired temperature is reduced.
A system such as that described generally in the preceding paragraph is the subject of a recently issued United States Patent which discloses a heat recovery device which is installed within the cool air return duct of a heating system to transfer the ordinarily wasted heat in the exhaust gases flowing through the flue pipe to the cool return air, thereby preheating the latter and increasing the efficiency of the heating system. The details of the device are drawn toward a complex three stage heat transfer structure which is disposed within a heat conductive tubular member which cooperates to transfer heat away from the gases into the cool return air by means of conduction, convection and radiation processes. A first stage deflects a portion of the gases toward and into heat exchanging contact with the sidewalls of the tubular member and in the second stage directs the remaining portion into a gas pervious heat storage trap. The third stage includes a perforated, heat deflecting and radiating cone structure which cooperates with the first and second stages to produce temperature stratification within the tubular member to further increase heat transfer to the cool return air.
Although devices such as that disclosed above are partially effective to transfer heat to the cool return air duct, such systems have a number of shortcomings. The products of combustion being vented in the duct contain poisonous carbon monoxide as well as other toxic gases which, if somehow were able to leak into the fresh air return could conceivably be circulated through the house and present a hazardous condition. Additionally, air, being a relatively good insulator, is not the most effective fluid for application within high capacity heat exchangers. Finally, such devices are often passive inasmuch as they provide no control of the furnace blower and thus only recover heat when the blower is cycled on. When the furnace blower is not on and air is not passing through the cool air return duct, very little heat would be transferred.
U.S. Pat. No. 2,189,748 to Windheim et al represents another approach taken in prior art heat recovery apparatus. In Windheim, a water heater is installed in the flue of a furnace wherein waste heat is captured by heating the water which subsequently supplements the normal hot water system within the home. Such approaches have limited value inasmuch as the supplemental heat to the hot water system is not always present and thus, a constant hot water temperature within the home is difficult to maintain. Additionally, a rupture of a water heating pipe within the flue could cause the water supply to the home to be directly discharged into the furnace with potential catastrophic results.
Still another prior art approach is disclosed in U.S. Pat. No. 4,136,731 to DeBoer. DeBoer discloses a heat transfer system for use in supplementing the operation of the heating/cooling system of a building and its hot water heating system, which includes a heat exchanger in the flue of the furnace as well as a heat exchanger in the fan (furnace) chamber. A first liquid circulation loop couples the heat exchangers for transferring heat from the flue exchanger to the air moved through the fan chamber heat exchanger. A second liquid circulation loop includes the flue exchanger and the building hot water heater for supplementing the heating of water therein. In the summer months during the cooling mode of the system's operation, cold water employed, for example, for lawn sprinkling is passed through the fan chamber heat exchanger for cooling and dehumidifying air circulated in the building. A valve control system is employed to automatically control the flow path of fluid in the system as a function of detected temperatures.
Although the DeBoer device is partially automated and represents an advance in the art, such devices contain many of the shortcomings described herein above and do not address the common situation of a system of appliances having multiple flues or coordinate operation of the heat recovery apparatus with the overall operation of the furnace itself to maximize heat recovery.
Finding a heat recovery device which overcomes the above outlined problems and reduces dependence on hydrocarbon fuels has recently become more urgent in light of the precipitus increase in the cost of such fuels as well as their predicted shortages.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a flue gas heat recovery apparatus which overcomes many of the above described shortcomings of the prior art and is intended for use with a forced air type furnace of the type which utilizes and external exhaust flue, a blower adapted for circulating heated air through a duct system and a cold air return duct system. According to the present invention, the heat recovery apparatus includes first and second heat exchangers, the first (gas to liquid) heat exchanger associated with the exhaust flue to extract heat therefrom and the second (liquid to gas) exchanger disposed within the cold air return duct. The second heat exchanger receives circulating liquid via a pump in response to the generation of a control signal. The circulation of fluid between the heat exchangers effects a net heat transfer from the gas within the flue to the air within the cold air return. Finally, control means is provided which monitors the temperature of the exhaust gas and operates to generate the control signal as a function of the temperature and preselected temperature level limits. Alternatively, and/or additionally, the control means monitors the temperature of the air flow exiting the furnace and generates the control signal as a function thereof. This arrangement has the advantage of providing a very simple and effective heat recovery apparatus which recovers heat from the furnace flue and transfers it to the cold air return duct of the furnace through a closed, low volume secondary liquid loop. This arrangement also has the advantage of isolating the exhaust gases and household water system from the fresh air portion of the furnace ducting system.
According to the preferred embodiment of the invention, an override feature is provided which will take control of normal operation of the furnace blower during generation of the control signal. This arrangement has the advantage of maximizing heat transfer during periods in which the exhaust gas is elevated above a predetermined temperature, irrespective of furnace operation.
According to another aspect of the invention, the first heat exchanger is also in thermal communication with the exhaust gas flue of a hot water heater, and operates to absorb the exhaust heat therefrom. This arrangement has the advantage of providing a flue gas heat recovery apparatus which simultaneously extracts heat from two (or more) appliances for use in enhancing operation of one of the appliances (furnace).
According to another aspect of the invention, duct means are provided which are operable to selectively reconfigure the exhaust flue associated with the hot water heater described immediately herein above to bypass the first heat exchanger. This arrangement has the advantage of providing for convenient seasonal reconfiguration of the flue gas heat recovery apparatus while retaining relative structural simplicity.
According to still another aspect of the present invention, the control means operates to initiate generation of the control signal when the exhaust gas temperature substantially equals a high temperature set point, and continues generation of the control signal until the gas temperature substantially equals a low temperature set point. This arrangement has the advantage of providing a hysteretic on-off control function for the pump means to prevent a possible unstable condition (as could occur if the turn-on and turn-off temperature set points coincided).
These and other features and advantages of this invention will become apparent upon reading the following specification, which, along with the patent drawing, describes and discloses a preferred illustrative embodiment of the invention in detail.
The detailed description of the specific embodiment makes reference to the accompanying drawing which illustrates, in schematic form, the present invention and its interface with a typical household forced air furnace and hot water heater.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, the preferred embodiment of an inventive flue gas heat recovery apparatus (hereinafter referred to as "the system"), shown generally at 10, is illustrated in schematic form. The system 10 is contemplated for application with a conventional household type gas fired furnace 12 as well as a gas fired hot water heater 14. Although the principally intended application of the system 10 is with furnaces and hot water heaters which consume combustible mixtures of fossil fuels and atmospheric oxygen, it is contemplated that the present invention can be readily adapted to any such home system of appliances which have pilot lights and consume fossil fuels, e.g. gas clothes dryers with varying degrees of success. The Applicant has found that the present invention is most easily accommodated by natural gas fired appliances whose exhaust gases are relatively free of particulate matter. To best take advantage of the present invention, oil fired appliances may require additional apparatus to remove soot or other matter from the exhaust gases which could accumulate to degrade system operation and potentially create a hazardous condition. Likewise, the application of the present invention with a clothes dryer would necessitate the application of additional equipment to filter exhaust lint. Such apparatus and equipment is not considered to be within the scope of the present invention.
The furnace 12 includes an upwardly elongated cabinet 16 which houses a gas burner manifold (not illustrated) which is connected to a source of natural gas. A vent hood or bonnet (also not illustrated) is positioned over the manifold to collect the products of combustion including carbon monoxide and vent them externally of the house or structure associated with the furnace 12 through a hot gas exhaust flue 18. In most installations, the flue 18 interconnects the furnace hood with a chimney formed of masonry which is positioned above the hood whereby the flue 18 promotes natural thermal aspiration of the hot flue gases by mechanisms well known in the art. The burner manifold has a continuously burning pilot light associated therewith which also consumes fuel and generates exhaust gas which is vented via the exhaust flue 18. For the purposes of the ensuing description, exhaust gas generated by the pilot light is not differentiated from that generated during burner-on operation of the furnace 12.
The upper end of the cabinet 16 opens into a hot air duct system 20 which passes throughout the structure intended to be warmed by the furnace 12 for distribution of the hot air generated within the furnace 12. A cold air return duct system is connected to a cold air return duct 22 which extends downwardly to near floor level, communicating with the lower end of the cabinet 16 through an intermediate blower chamber 24. A furnace blower fan and motor 26 and 28, respectively, are positioned at an interface 29 between the blower chamber 24 and the cabinet 16, which defines an airflow directing aperture 27 therein which circumscribes the fan 26. The fan 26 operates, when energized, to draw cold return air into the cold air return duct 22, pass it into the cabinet 16 for heating and return it under pressure to the structure to be heated via the hot air duct 20. A switch, thermostat or other suitable control apparatus 30 operates to cycle the blower fan 26 by energizing the motor 28. This energization can occur manually or automatically by employing control apparatus such as thermostats which are well known in the art. The structural arrangement described herein is considered by the applicant to be of conventional design and is included only as an illustrative environment for the present invention. The fan 26, motor 28 and switch 30 are the units which would preexist in any similar installation.
The hot water heater 14 is likewise of conventional design having a first pipe 32 connected to a source of fresh potable water and a second pipe 34 connected to the household hot water distribution system. The hot water heater 14 has a gas burner manifold, pilot burner and hood (not illustrated) which, like the furnace 12, collects the constituents of combustion (both from the pilot light and burner-on operation of the manifold) and vents them externally of the building via a hot gas exhaust flue 36. As with the hot gas exhaust flue 18 from the furnace 12, the flue 36 is connected to the chimney for ultimate venting into the atmosphere. Both the furnace 12 and the hot water heater 14 draw air from the immediately surrounding atmosphere through inlets 31 and 33, respectively, to support pilot light combustion.
The inventive flue gas heat recovery apparatus or system 10 includes a first, or gas-to-liquid type, heat exchanger indicated generally at 38 which is disposed within a thermally insulated cabinet 40 or other suitable structure which also encases a portion of the flues 18 and 36. The system 10 also includes a second, or liquid-to-gas type, heat exchanger indicated generally at 42 which is disposed within the cold air return duct 22 where it transitions into the blower chamber 24. The heat exchangers 38 and 42 are circuitiously fluidically interconnected by a series of water carrying conduits 44a through 44c which operate to circulate water therebetween under the influence of a series connected pump 46. Although the pump 46 is illustrated as being distinct from the motor 28, it is contemplated that, as an optional embodiment, the motor 28 could be integrated with, and directly mechanically drive the pump 46.
The conduit 44a interconnects the input port of pump 46 with an outlet port 38a of the heat exchanger 38 where it emerges from the cabinet 40. Another conduit 44b interconnects the outlet port of the pump 46 with an inlet port 42a of the heat exchanger 42 where it emerges from the cold air return duct 22. The outlet port 42b of the heat exchanger 42 is connected to one end of a conduit 44c where it emerges from the cold air return duct 22. The other end of the conduit 44c is connected to the inlet port 38b of the heat exchanger 38 where it emerges from the cabinet 40. The conduits 44a through 44c are constructed of copper, steel pipe or other suitable material of a small enough diameter to minimize the transit time of fluid flowing therethrough. This minimizes the heat rejection from the fluid through the conduit. Heat loss can also be reduced by the use of insulation around the outer surfaces of conduits, particularly the conduit 44a and 44b which transports the hottest water and thus has the greatest thermal gradient thereacross.
The cabinet 40 is sealed and inserted serially in line with the hot gas exhaust flues 18 and 36 whereby gas enters the cavity defined by the cabinet 40 from the portion of the flue 18 which interconnects the cabinet 40 with the furnace cabinet 16 and from the portion of the flue 36 which interconnects the cabinet 40 with the hot water heater 14. Baffles or diffusers (not illustrated) are provided within the cabinet 40 to disburse incoming hot exhaust gases received from the furnace 12 and the hot water heater 14 throughout the entire extent of its cavity. The diffusers are sized and positioned so as to prevent straight through flow of the exhaust gases while creating an acceptably low pressure drop across the cabinet 40. Within the cabinet 40, the hot gases swirl about a coil 38c of the heat exchanger 38 and impart a substantial portion of their thermal energy thereto. The cooled exhaust gases then pass upwardly through the flues 18 and 36 to be vented via the chimney. In the preferred embodiment of the invention, the flues 18 and 36 are constructed of four inch and six inch steel tubing, respectively, and the cabinet 40 of the heat exchanger 38 is formed of sheet metal of the type used in standard residential ducting systems.
The heat exchangers 38 and 42 are of the type in which relatively extensive lengths of metallic tubing or conduit is shaped in serpentine fashion to form a planar coil and distributed laterally across the extent of a low path of an air duct, gas flue or other gaseous medium. The metal is typically copper, aluminum or other highly thermally conductive material which readily transfers heat between the fluid flowing within the conduit and the air passing outside thereof. Heat transfer is enhanced by the use of aluminum fins on the serpentine coil to greatly increase the outer surface area and thus the heat radiating/absorbing ability thereof. Such structure is well known in the art and the details thereof are deleted here for the sake of brevity.
Likewise, mounting of the heat exchangers in their respective positions will not be detailed herein for the sake of brevity, it being understood that such structure will be obvious to one of ordinary skill in the art in view of the present specification. A filter 48 is provided by conventional mounting means within the cold air return duct 22 upstream of the heat exchanger 42 to remove any foreign matter which enters the duct system within the structure to prevent contamination of the heat exchanger 42 which could otherwise lose efficiency over time. A four inch fresh air intake opening 50 is provided in the cold air return duct 22 to draw atmospheric air therein to make up for any air lost in the combustion process within the furnace 12 or heat distribution network. Although the intake opening 50 is illustrated as communicating with the atmosphere immediately adjacent the cold air return duct 22, make-up air is drawn from outside the heated structure. A damper 52 is mounted to the cold air return duct 22 by a screw 51 or other suitable fastener and operates as a manually operated valving element to control the amount of make-up air drawn through the intake opening 50.
The coils of the heat exchanger 38 and 42 as well as the conduits 44a through 44c collectively form a closed circuit or loop within which water or other suitable liquid circulates under the influence of pump 46. Because the water flowing within the conduits 44a through 44c is at an elevated temperature and pressure, a 15 pound per square inch (psi) relief valve 54 is incorporated within the circuit in the conduit 44c to provide overflow to a low pressure (atmospheric) drain 55 via a vent tube 56, should the water pressure within the loop exceed that level. Additionally, an expansion tank 58 and an air relief and purge valve 60 are added to the loop at the conduit 44b. The expansion tank operates to absorb mechanical shock due to abrupt starting and stopping of the mass of fluid within the loop when the pump 46 is energized and deenergized as well as providing additional volume when needed due to thermal expansion of the water. The air relief and purge valve 60 operates to remove any air which may inadvertently enter the fluid circulating within the loop. Finally, a source of make-up water 62 is connected to the conduit 44c via a manually operated valve 64 to make up for any water in the loop which may be lost due to leakage, evaporation or the like.
Control of the system 10 is effected by the use of a fluid temperature thermostat 66 mounted within the cabinet 40 enclosing the heat exchanger 38. The thermostat 66 is positioned to sense the temperature of the hot exhaust gases within the cabinet 40 and to feed electrical signals to a control circuit 70 via a conductor 71. An additional, optional thermostat 67 consisting of a transducer can be provided to sense the temperature of the air within the cold air return duct 22 if such a parametric input is desired. A pressure transducer 68 and thermometer 69 mounted within the conduit 44b provide local visual indication of the systems operation. The control circuit 70 is connected to a source of electrical household current (not illustrated) and operates to energize the pump 46 via an electrical line 72 when the sensed fluid temperature of the exhaust gases within the cabinet 40 enclosing the heat exchanger 38 reaches 100 degrees Fahrenheit and to subsequently switch the pump 46 off when the fluid temperature of the exhaust gases falls below 80 degrees Fahrenheit The specified temperatures were those which were experimentally found by the applicant to produce acceptable results for a specific structure being heated and thus are included here only to be by way of an example. The control circuit 70 is also electrically connected to a relay 74 which is electrically disposed intermediate switch 30 and the blower motor 28 to override operation thereof by directly energizing the blower motor 28 whenever the pump 46 is also energized for purposes which will become apparent herein below.
Finally, a four inch tubular metal bypass or discharge flue pipe 76 interconnects a point upstream with a point downstream of the cabinet 40 within the hot gas exhaust flue 36 and includes several manually operated dampers 78 which allow for bypass of the heat exchanger 38 during summer use by opening the dampers 78 within the bypass pipe 76 and closing the damper 78 within the hot gas exhaust flue 36.
The system 10 operates as follows:
When energized by a control signal on the line 72, the pump 46 circulates fluid circuitiously through the conduits 44, and the heat exchangers 38 and 42 at a nominal 14 pounds of pressure. The control circuit 70 operates purely as a function of the sensed temperature within the heat exchanger 38 and is thus independent of furnace operation. Whenever enough heat cumulatively passes through exhaust flues 18 and 36, sufficient to raise the temperature of gases within the cabinet 40 above 100 degrees Fahrenheit, the control circuit 70 will receive a first signal from the thermostat 66 via the line 71. The control circuit 70 then simultaneously energizes the pump 46 via the line 72 and the motor 28 via the relay 74 to cause the water within the loop to be circulated and to effect a net heat transfer from the heat exchanger 38 to the heat exchanger 42. Because the motor 28 is energized, air will be circulating through the furnace irrespective of normal sequencing of furnace operation. Therefore, cool air will be drawn into the cold air return duct 22 and past heat exchanger 42 which, because it is relatively warm with respect to the returning cold air, will impart heat to the air prior to its entering the furnace 12. By reducing the difference in temperature between returning cold air and the hot air emitted from the furnace 12, into the hot air duct 20, more efficient operation can be achieved whereby the heat which otherwise would be lost from the building via the flues 36 and 18 is transmitted to the water within the loop and ultimately imparted to the air in the cold air return duct 22.
The pump 46 and the motor 28 will remain energized until the temperature of the exhaust gases within the cabinet 40 falls below 80 degrees Fahrenheit, at which time a second signal is received from the thermostat 66 via the line 71, and the pump 46 will cease to operate and the motor 28 will be returned to the control of switch 30 for normal furnace operation and sequencing.
The effectiveness of combining appliances (the furnace 12 and the hot water heater 16) is evidenced by observations by the Applicant that, in one installation, the net effect of adding the hot water heater alone was to increase the outlet air temperature of the furnace 12 by 5 degrees.
The present inventive flue gas heat recovery apparatus is relatively simple to operate and maintain and is constructed entirely of commercially available materials. The actual circuit of the control 70 and its associated transducers and relays was not given in detail inasmuch as any number of different circuits can perform the same function as now should be obvious to one of ordinary skill in the art.
Restated, the theory of operation of the system 10 is this. Heat is absorbed from the hot gases in the flues 18 and 36 and transferred to fluid flowing through the heat exchanger 38. The heated liquid is circulated through a closed loop to a second heat exchanger 42 within the cold air return duct 22 which expels the heat to the fresh air entering the furnace 12 to reduce the furnace air in/out temperature differential. This effects a net heat transfer to the cold air return duct.
The heat exchanging water is circulated through a closed loop by the pump 46 which is energized via a control signal by the control circuit 70. The control circuit 70 is hysteretic in that it does not turn the pump 46 on until the exhaust gas temperature equals 100 degrees Fahrenheit (the upper or high temperature set point) and does not turn it off until the exhaust gas water temperature equals 80 degress Fahrenheit (the lower or low temperature set point). This effect can be achieved by the thermostat 66 consisting of a single fluid temperature transducer having two discrete independent set points or two distinct separately calibrated transducers. More sophisticated control could be employed through the use of a microprocessor control and the optional thermostat 67.
In an alternative embodiment of the invention, thermostat 66 can be optional and the control circuit 70 operates to energize pump 46 as a function of the operation of motor 28 whereby pump 46 will operate whenever motor 28 does.
It is to be understood that the invention has been described with reference to a specific embodiment which provides the features and advantages previously described, and that such specific embodiment is susceptible of modification as will be apparent to those skilled in the art. For example, the specified materials or the temperature limits specified in the preferred embodiment for actuation of the control circuit can be readily altered to suit another application. Accordingly, the foregoing description is not to be construed in a limiting sense. | A flue gas heat recovery apparatus is employed with a system of appliances such as a gas furnace and hot water heater, each having separate exhaust gas flues. The apparatus includes a gas-to-liquid heat exchanger in thermal communication with the two flues to simultaneously extract heat therefrom and a liquid-to-gas heat exchanger disposed within the furnace cold air return duct. A pump circulates water between the exchangers in response to a control signal to employ the recovered heat to preheat the cold air entering the furnace through the cold air return duct. A hysteretic control circuit monitors exhaust gas temperature and provides for system operation between high and low gas temperature limits. In the preferred embodiment of the invention, a furnace blower override feature is employed to energize the blower during periods of pump operation. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a method for preparation of an absorbent composite having an absorbent polymer firmly fixed to a substrate. More particularly, the invention relates to a method of manufacturing easily and at high productivity an absorbent composite excellent in absorption capacity, outstandingly low in the residual monomer in the absorbent polymer, and superior in safety, in which the absorbent polymer does not drop off the substrate even after absorbing a large quantity of water, a method of manufacturing continuously and at high productivity, a product obtained from these methods, and an apparatus to be used in such methods.
Recently as the means of obtaining absorbent composite by fixing an absorbent polymer to a substrate, various methods of applying a water-soluble monomer which can be converted into an absorbent polymer on a substrate, and then polymerizing have been proposed (for example, the Japanese Official Patent Provisional Publication Nos. 60-149609, 62-243606, 60-151381, and 62-243612). Since the polymerization reaction of water-soluble monomer in such proposed methods is impeded by oxygen and others existing in the air, it is performed in a polymerization-inert atmosphere such as an oven completely replaced by nitrogen gas.
By these known methods, however, when polymerizing the monomer applied on the substrate, it is required to keep the substrate in a specifically determined condition for a long period, and the apparatus for polymerization itself becomes large in size, and the energy loss is significant, and it is not advantageous for manufacturing absorbent composite industrially. Besides, the absorption capacity of the obtained absorbent composite was insufficient, and the amount of the residual monomer was too much.
OBJECTS OF THE INVENTION
This invention is intended to solve the above problems for industrially manufacturing absorbent composites.
It is hence a primary object of the invention to present a method of easily and efficiently manufacturing an absorbent composite having an absorbent polymer firmly fixed to a substrate, exhibiting an excellent absorption capacity without the polymer dropping off the substrate even after swelling of the polymer, and very low in the residual monomer in the absorbent polymer.
It is other object of the invention to present a method of manufacturing such absorbent composite easily, efficiently, and continuously.
It is a different object of the invention to present an absorbent composite preferably used as sanitary material such as disposable diapers produced in such manufacturing methods.
It is a further different object of the invention to present a manufacturing apparatus to be used in the continuous manufacturing method.
SUMMARY OF THE INVENTION
This invention relates to a method of preparation of an absorbent composite in which an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization is applied to a substrate, and the monomer is polymerized while the substrate to which the aqueous solution is applied is, on both the sides, held in contact with polymerization-inert surfaces facing each other.
The invention also relates to a continuous manufacturing method of an absorbent composite characterized by continuously passing in the sequence of
1. the region of applying to a substrate an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization, and
2. the region of polymerizing the monomer in the state of holding the substrate, on both the sides, in contact with polymerization-inert surfaces facing each other, while moving the substrate.
The invention further relates to a manufacturing apparatus of an absorbent composite comprising the following means 1 and 2 arranged along the moving route of the substrate for applying to the substrate, while moving the substrate continuously, an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization, polymerizing the monomer under a condition that the substrate is, on both the sides, held in contact with polymerization-inert surfaces facing each other, and thereby fixing the absorbent polymer to the substrate.
(1) Means for applying to a moving substrate an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization.
(2) Polymerization means possessing facing polymerization-inert surfaces and means for setting a gap of a clearance corresponding to the thickness of the substrate between the facing polymerization-inert surfaces, for polymerizing the monomer while the substrate to which the aqueous solution is applied is passing through the gap to fix the absorbent polymer to the substrate.
The substrate to be used in the present invention is not particularly limited as far as it is wanted to have an absorption property, and a proper one may be selected from various materials depending on the application of the obtained absorbent composite. Practical examples may include sponge and spongy porous substrates such as synthetic resin foam, and fibrous substrates of paper, string, non-woven fabric, woven fabric and the like made of synthetic fibers such as polyester and polyolefin, cellulose fibers such as cotton and pulp, and others. As a substrate of a long size used in the continuous manufacturing method, it is not particularly limited as far as the length is sufficient for continuously passing the polymerization region and drying region mentioned later, and a proper one may be selected from various materials depending on the application of the obtained absorbent composite (for example, as listed above). Or, in the continuous manufacturing method, instead of the substrate of a long size, a substrate of a short size or substrates of various lengths may be also used. For example, when the substrate is moved by putting on a substrate moving table such as belt and tray, it may be applied also in the continuous manufacturing method. In this case, when the face of the substrate moving table contacting with the substrate is a polymerization-inert surface, it is convenient for polymerization.
As the water-soluble ethylenically unsaturated monomer used in the invention, it is not particularly limited as far as it can be converted into an absorbent polymer by polymerization, and practical examples may include unsaturated monomers containing carboxyl group such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, other unsaturated carboxylic acids, and their lithium, sodium, potassium and other alkaline metal salts, ammonium salt and organic substitutional ammonium salts; unsaturated monomers containing sulfonic group such as 2-(meth)acryloylethane sulfonic acid, 2-(meth)acryloylpropane sulfonic acid, (meth)acryloylpropane-2-sufonic acid, 3-(meth)acryloylpropane sulfonic acid, 2-(meth)acryloylbutane sulfonic acid, (meth)acryloylbutane-2-sulfonic acid, 4-(meth)acryloylbutane sulfonic acid, 2-(meth)acrylamido-2-methylpropane sulfonic acid, 2-(meth)acrylamidoethane sulfonic acid, 3-(meth)acrylamidopropane sulfonic acid, 4-(meth)acrylamidobutane sulfonic acid, vinyl sulfonic acid, (meth)allylsulfonic acid, other unsaturated sulfonic acids, and their alkaline metal salts, calcium, magnesium, other alkaline earth metal salts, ammonium salt, and organic substitutional ammonium salts, water-soluble unsaturated monomers such as (meth)acrylamide, (meth)acrylonitrile, vinyl acetate, N,N-dimethylaminoethyl (meth)acrylate, and its quartenary compounds and others; and (meth)acrylic acid esters such as hydroxyethyl(meth)acrylate, hydroxypropyl-(meth)acrylate, polyethylene glycolmono(meth)acrylate, polypropylene glycolmono(meth)acrylate, methoxypolyethylene glycolmono(meth)acrylate, methoxypolypropylene glycolmono(meth)acrylate, methoxypolybutylene glycolmono(meth)acrylate, ethoxypolyethylene glycolmono(meth)acrylate, ethoxypolypropylene glycolmono (meth)acrylate, ethoxypolybutyrene glycolmono(meth)acrylate, methoxypolyethylene glycol-polypropylene glycolmono(meth)acrylate, phenoxypolyethylene glycolmono (meth)acrylate, benzyloxypolyethylene glycolmono(meth)acrylate, methyl(meth)acrylate, ethyl(meth)acrylate, and butyl(meth)acrylate, and one or more types thereof may be used. Among them, preferably, a desired material is at least one monomer selected from a group comprising (meth)acrylic acid and its salt, 2-(meth)acryloylethane sulfonic acid and its salts, 2-(meth)acrylamido-2-methylpropane sulfonic acid and its salt, and (meth)acrylamide. More preferably, (meth)acrylic acid and/or its salt is the principal ingredient of the water-soluble ethylenically unsaturated monomer. In this case, considering the reactivity of monomer and absorption characteristic of the obtained absorbent composite, the content of (meth)acrylic acid and its salt is preferably in a range of 50 to 100 mol % of the entire water-soluble ethylenically unsaturated monomer.
The monomer concentration in aqueous solution is not particularly defined, but it is desired to be in a range from 20 wt. % to saturated concentration, considering the labor in drying procedure of the obtained absorbent composite, or more preferably from 30 to 70 wt. %.
As the water-soluble radical polymerization initiator used in this invention, hitherto known compounds may be listed, for example, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; peroxides such as hydrogen peroxide, and t-butyl hydroperoxide; and azo compounds such as 2,2'-azobis(2-amidinopropane)dihydrochloride, and 2,2'-azobis(N,N'-dimethylene isobutylamidine)dihydrochloride. Though each of these polymerization initiators may be solely used, two or more types of them may be also used by mixing, or they may be used as redox initiators by combining with reducing agents such as sulfites, L-ascorbic acid, and ferrous chloride.
In this invention, in addition to the water-soluble ethylenically unsaturated monomer, it is desired to contain a crosslinking agent in the aqueous solution to be applied to the substrate. Practical examples of crosslinking agent may include, for example, compounds (a) possessing two or more ethylenically unsaturated groups in one molecule, and/or compounds (b) possessing two or more groups reacting with functional groups such as carboxylic group and sulfonic group in the water-soluble ethylenically unsaturated monomer. Practical examples of said compounds (a) may include, for example, ethyleneglycoldi(meth)acrylate, diethyleneglycoldi(meth)acrylate, triethyleneglycoldi(meth)acrylate, trimethylolpropanetri(meth)acrylate, pentaerythritoltri(meth)acrylate, pentaerythritoldi(meth)acrylate, N,N'-methylenebis(meth)acrylamide, triallyl isocyanurate, and trimethylolpropane diallylether. Practical examples of said compounds (b) may include, for example, polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, triethanolamine, polypropylene glycol, polyvinyl alcohol, pentaerythritol, sorbit, sorbitan, glucose, mannit, mannitan, and sucrose; polyepoxy compounds such as ethylene glycol diglycidylether, glycerin diglycidylether, polyethylene glycol diglycidylether, propylene glycol diglycidylether, polypropylene glycol diglycidylether, neopentyl glycol diglycidylether, 1,6-hexane glycol diglycidylether, trimethylol propane diglycidylether, trimethylol propane triglycidylether, and glycerin triglycidylether; and polyamine compounds such as ethylene diamine and polyethyleneimine. One or more types of each of said compounds (a) and (b) may be used.
When a polyhydric alcohol is used as the crosslinking agent, it is desired to keep the ambient temperature after polymerization (the ambient temperature in the drying region in the continuous manufacturing method) in a range of 150° to 250° C., for heat treatment of the absorbent composite, and when a polyepoxy compound is used, it is desired to keep in a range of 50° to 250° C.
Use of a crosslinking agent is desired in that the ratio of absorption of the obtained absorbent composite may be easily controlled. The crosslinking agent may be used not only by contained in the aqueous solution to be applied on the substrate, but also by sprinkled over the substrate after polymerization (for example, the substrate in the process of passing through the drying region) to realize secondary crosslinking of the formed absorbent polymer.
The content of the water-soluble radical polymerization initiator in the water-soluble ethylenically unsaturated monomer is not particularly defined, but it is desired to add the initiator by 0.01 to 5 parts (by weight) to 100 parts of monomer. If the content of the initiator is less than 0.01 part, the polymerization of monomer may not be complete, and if the content is larger than 5 parts, the absorption capacity of the absorbent polymer formed by polymerization may be lowered. The content of the crosslinking agent, if used, is not particularly limited, but it is desired to use the crosslinking agent by 0.005 to 5 parts (by weight) to 100 parts of monomer. If the crosslinking agent is added excessively or insufficiently, the absorption capacity of the absorbent polymer produced by polymerization may be lowered.
Methods for applying an aqueous solution containing the water-soluble ethylenically unsaturated monomer and water-soluble radical polymerization initiator (hereinafter sometimes called aqueous monomer solution) to the substrate may include the coating by known printing or textile printing methods such as spraying, brushing, roller coating and screen printing, and impregnation of the substrate with the aqueous solution followed by squeezing off to a specified amount. The means for such application of the aqueous solution is disposed in the applying region. Though the amount of the aqueous monomer solution to be deposited on the substrate is not particularly limited, it is generally in the range of 0.1 to 100 parts by weight, preferably 0.5 to 20 parts by weight, based on 1 part by weight of the substrate. The mode of deposition of aqueous monomer solution may be either uniform on the entire surface of the substrate, or non-uniform, such as stripe, lattice, dot and other patterns.
When applying the aqueous monomer solution to the substrate, in order to enhance the absorption capacity of the obtained absorbent composite as well as the efficiency of deposition, thickener and other additives may be contained in the aqueous monomer solution. Such additives may include, for example, polyacrylic acid (or its salt), polyvinyl pyrrolidone, hydroxyethyl cellulose, and pulp fibers.
In this invention it is essential to perform polymerization reaction while holding the substrate, to which the aqueous monomer solution is applied, on both the sides, in contact with polymerization-inert surfaces facing each other. By polymerization or as required afterwards, the substrate after polymerization is dried, and the absorbent composite of the present invention is obtained. In the case of continuous manufacturing method, practically, the substrate to which the aqueous monomer solution is applied is led into the polymerization region comprising an apparatus possessing polymerization-inert surfaces for holding the substrate, and is passed between the facing polymerization-inert surfaces to obtain the absorbent composite by polymerization, or after polymerization, the substrate may be continuously passed in the drying region comprising an apparatus for heating the substrate, while holding the substrate in a gas in succession.
The polymerization-inert surfaces may be any surfaces that would not allow to pass oxygen and others which may impede the polymerization of water-soluble monomer, which may include, for example, glass fiber and other ceramics, steel and other metals, fluororesin, silicone resin, polyester resin and other plastics, being manufactured in the forms of belt, roll, film, sheet, plate, etc. These surfaces are preferably finished in mirror-smooth surface or treated with fluororesin in order to prevent sticking of the absorbent polymer produced in the polymerization process.
The distance (clearance) of the facing polymerization-inert surfaces may be set, for example, to be equivalent to the thickness of the substrate in a stationary state, or the thickness measured in pressure-free state. A proper clearance may be adjusted by placing an adjuster (such as a screw) between the support members for supporting the facing polymerization-inert surfaces, and moving one of the surfaces closer to or remoter from the other by turning the screw. In this case, it is convenient for handling substrates of different thickness. Or when a press plate is used, a spacer having proper thickness (for example, equivalent to thickness of the substrate) may be placed between the two surfaces.
Moreover, in order to promote the polymerization to a high degree of polymerization without delay followed by obtaining an absorbent composite excellent in absorption capacity, it is desired to heat the substrate held by the facing polymerization-inert surfaces during polymerization. Specifically, the substrate may be heated in contact by surfaces of facing belts or the like set to a desired temperature by an electric heater, steam or the like, in the held state, during polymerization, the substrate held between surfaces of facing belts is indirectly heated by microwaves, or the substrate may be held by heated press plates.
The temperature of the substrate upon start of polymerization may differ depending on the type and quantity of radical polymerization initiator, or type and concentration of monomer, but it is generally preferable to keep the decomposition temperature or more of the radical polymerization initiator. Practically, in the case of contact heating, the temperature of the surfaces for holding the substrate may be preferably kept at 50° to 150° C., or more preferably 100° to 120° C. If the temperature is less than 50° C., it is difficult to promote the polymerization promptly to a high degree of polymerization, and if higher than 150° C., the substrate may deteriorate, or the polymerization may be promoted abruptly, making it difficult to control the polymerization, which is not desired. Besides, once the polymerization is started, since heat is generated, it is desired to control the polymerization by adjusting the temperature of surfaces holding the substrate.
Furthermore, in order to promote the polymerization smoothly to a high degree of polymerization, it is desired to keep the surroundings of the facing polymerization-inert surfaces in a polymerization-inert gas atmosphere such as nitrogen.
The time for performing polymerization is not particularly defined, but it is generally 1 to 10 minutes in contact heated polymerization, 10 to 60 seconds in indirectly heated polymerization. In the case of continuous manufacturing method, the substrate may be passed through the facing polymerization-inert surfaces by taking such time as mentioned above.
In this invention, the polymerization may be directly controlled through surfaces holding the substrate, and since the substrate is held by facing surfaces, the effects of fluctuation of monomer concentration due to evaporation of water and oxygen and others which may impede polymerization may be eliminated, and hence the absorbent composite excellent in absorption capacity and far less in the residual monomer may be manufactured easily and at high productivity.
Thus, when the monomer applied to the substrate is polymerized under a condition that the substrate to which the aqueous monomer solution is applied is held by facing polymerization-inert surfaces, an absorbent composite having the water-containing gel of the absorbent polymer formed by polymerization firmly fixed to the substrate will be obtained. However, depending on the monomer concentration of aqueous monomer solution being used, a certain tackiness may be caused in the obtained absorbent composite, and it may be inferior in handling, and therefore it is desired to dry the absorbent composite as required after polymerization.
Any drying method may be applicable, such as the means for hot air, microwaves, infrared rays, and ultraviolet rays.
In the continuous manufacturing method, too, the substrate passing through the polymerization region is sequentially led into the drying region, if drying is necessary, where the substrate is dried, and a desired absorbent composite is obtained.
The drying region in this invention comprises an apparatus for heating the substrate while holding the substrate in a gas, and the examples of a gas may include the air, an inert gas such as nitrogen, steam-air mixture, steam-inert gas mixture, and steam, and the apparatus for holding the substrate in the gas atmosphere may be, for example, rotatable support rolls and support belts, and examples of heating apparatus may include heater with fan for generating hot gas, and machines generating microwaves, infrared rays, ultraviolet rays, and others.
The substrate heating temperature in the drying region may be properly set in consideration of the drying efficiency, and it is desired to keep under 250° C. in order to prevent deterioration of absorbent polymer. Or, from the viewpoint of absorption capacity of the obtained absorbent composite, it is desired to heat 80° C. or more.
The substrate retention time in the drying region is arbitrary, and basically the substrate is kept within the drying region until the tackiness is eliminated from the obtained absorbent composite. Or, by pressure-bonding and drying other substrate to the absorbent composite before the tackiness is eliminated, the absorbent composite and other substrate may be glued together.
In the case of continuous manufacturing method, the substrate moving speed may be set properly depending on the time required for polymerization or drying in the polymerization region or drying region, and the area of these regions, and it is not particularly defined. From the viewpoint of industrial productivity, the moving speed of the substrate is preferably 0.1 to 100 m/min.
Besides, in the drying region, in order to partially change the absorption capacity of the obtained absorbent composite, a compound possessing two or more functional groups capable of reaction with functional group, such as carboxyl group and sulfonic group, for example, polyvalent metal salts and polyethylene glycol diglycidylether may be partly applied to the substrate.
According to the method of the present invention, the absorbent composite having the absorbent polymer firmly fixed to the substrate may be easily and efficiently manufactured using simple equipment.
According to the apparatus of the present invention, a clearance between facing polymerization-inert surfaces may be easily set and such continuous method may be executed.
Besides, the absorbent composite manufactured by the method of the present invention is excellent in absorption capacity, and is outstandingly low in the residual monomer content in the polymer, and therefore it is free from adverse effects on the human health or environments, and it may be hence used widely in sanitary materials, foods, civil engineering, building materials, electric power, agriculture and other fields where absorption and water retaining properties are required.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram for showing a first embodiment of the apparatus for executing the continuous manufacturing method of the invention,
FIG. 2 is a schematic diagram for explaining a part thereof,
and FIG. 3 is a schematic diagram for explaining other embodiment of the apparatus for executing the continuous manufacturing method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the continuous manufacturing method of the present invention is described below. FIG. 1 is a schematic diagram showing an example of the apparatus for executing the continuous manufacturing method of the invention, FIG. 2 is a schematic explanatory drawing magnifying a part thereof, and FIG. 3 is a schematic diagram showing other example of the apparatus.
In the apparatus shown in FIG. 1, the polymerization region is composed of endless belts 1A and 1B for holding a substrate 10 on both the sides, and steam heaters 3A and 3B are disposed in the vicinity of the contacting surfaces of the endless belts 1A and 1B with the substrate 10 for heating the substrate 10. Besides, in the apparatus shown in FIG. 1, the drying region comprising a hot air dryer 6, and the substrate 10 is held in the atmosphere of the circulating hot air by means of a support roll 9.
On the other hand, in the apparatus shown in FIG. 3, the polymerization region is composed of a drum roll 13 and an endless belt 14 which is disposed so as to cover part of the circumference of the drum roll 13, and the substrate 10 is held between the circumferential surface of the drum roll 13 and the surface of endless belt 14. Moreover, in the apparatus shown in FIG. 3, the drying region comprises a compartment for heating the substrate 10 with infrared irradiation from an infrared lamp 15.
A substrate of a long size 10 is let off from the let-off roll 7, and is continuously taken up on a take-up roll 8 after passing through the polymerization region and drying region, and the take-up roll 8 is rotated and driven in the winding direction of the substrate 10.
In the apparatus shown in FIG. 1, the substrate 10 is first immersed in an aqueous monomer solution 4, and the excess aqueous monomer solution is squeezed off by a squeeze roll 5.
The substrate 10 thus applied with the aqueous monomer solution is subjected to monomer polymerization in a state that the substrate is, on both the sides, held in contact with facing surfaces of the endless belts 1A and 1B.
The clearance C between the facing surfaces of the endless belts 1A and 1B is set, for example, by a clearance adjuster 20 shown in FIG. 2. The clearance adjuster 20 is placed between the support member 21A and 21B of the belt drive rolls 2A and 2B. The support member 21A is fitted at both ends of the two belt drive rolls 2A, and the support member 21B is fitted at both ends of the two belt drive rolls 2B. The clearance adjuster 20 is driven in the mutually opposing winding threads to the support members 21A and 21B. When the clearance adjuster 20 is turned in one direction (for example, clockwise), the support members 21A and 21B approach to each other, and the clearance C is narrowed, and when turned in the other direction (for example, counterclockwise), the support members 21A and 21B become remote from each other, so that the clearance C is widened. The clearance C is adjusted in this way, for example, so as to be equivalent to the thickness of the substrate 10.
The endless belts 1A and 1B are driven in the moving direction of the substrate 10 by the belt drive rolls 2A and 2B, respectively, and the peripheral speed of the endless belts 1A and 1B is preferably tuned with the peripheral speed of the take-up roll 8. In the vicinity of the contacting surface of the endless belts 1A and 1B with the substrate 10, steam heaters 3A and 3B are disposed for promoting the polymerization reaction, so that the substrate 10 is heated.
The substrate passing through the polymerization region is led into the hot air drier 6. In the drier 6 in which hot air is circulating, the substrate is dried as being held in the air by the support roll 9.
When dried until the tackiness is eliminated from the substrate in the drying region, the substrate leaves the drier 6, and is taken up on the take-up roll 8, so that a product of absorbent composite 11 is obtained.
In the apparatus shown in FIG. 3, in order to apply the aqueous monomer solution onto the substrate, the aqueous monomer solution is sprayed onto the substrate 10 from a spray nozzle 12. The substrate 10 first passes through the polymerization region under a condition that the substrate is, on both the sides, held in contact with the circumferential surface of the heated drum roll 13 and the surface of endless belt 14, and the monomer is polymerized. Next, the substrate 10 passes near the infrared lamp 15, and is heated and dried by the infrared rays emitted from the lamp 15, thereby becoming an absorbent composite 11.
The present invention is further described below while referring to embodiments, but it must be noted that the scope of the invention is not limited to the illustrated embodiments alone. Meanwhile, the absorption performance of the absorbent composite (ratio of absorption), the amount of the residual monomer in the absorbent polymer in the absorbent composite, and the drop-off rate of absorbent polymer mentioned in the embodiments were measured in the following testing methods.
(1) Ratio of Absorption
A bag (40 mm ×150 mm) made of non-woven fabric after the fashion of a tea bag and containing a given absorbent composite, 0.5 g in weight, in a finely cut form was immersed in an aqueous solution of 0.9% by weight of sodium chloride for 30 minutes. Then, the bag was pulled out of the aqueous solution, drained for 5 minutes, and weighed. The ratio of absorption of the absorbent composite was calculated in accordance with the following formula. ##EQU1##
(2) Amount of Residual Monomer
A given absorbent composite was weighed out in an amount containing 0.5 gr. of solids of absorbent polymer, finely cut, and dispersed by stirring in 1 liter of purified water. The resultant dispersion was left standing for two hours and then passed through a glass microfibre filter paper (produced by Whatman Paper Ltd. and marketed under trademark designation of "Whatman filter paper"). The filtrate was tested by high-performance liquid chromatography (HPLC) for residual monomer content. The amount of the residual monomer in the absorbent polymer was calculated from the result of the test.
(3) Drop-off Rate of Absorbent Polymer
A test piece of 5×5 cm was immersed in an excess 0.9 wt. % saline solution for 1 hour, and the swollen test piece was pulled up, and the remaining brine was filtered by a 100-mesh wire net.
The polymer on the wire net was dried in hot air for 1 hour at 120° C., and weighed, and the lost polymer amount was determined, and the polymer drop-off rate was determined in the following equation.
Meanwhile, the test piece was preliminarily dried at 120° C. for 1 hour, and the weight of the absorbent composite was obtained. ##EQU2##
EMBODIMENT 1
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 40 wt. %) with 75 mol% neutralized by sodium hydroxide, 0.2 part by weight of 2,2'-azobis(N,N'-dimethyleneisobutyl-amidine)dihydrochloride and 0.005 part by weight of N,N'-methylenebisacrylamide were dissolved, and dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
This aqueous monomer solution was screen-printed on a polypropylene nonwoven fabric having 30 g/m 2 of basis weight, and the deposition of aqueous monomer solution was set at 250 g/m 2 .
This nonwoven fabric applied with aqueous monomer solution was, on both the sides, held for 5 minutes in contact with two facing mirror-finished steel press plates heated to 60° C. through a spacer in the same thickness as the thickness of the nonwoven fabric in a stationary state, and the monomer was polymerized.
The nonwoven fabric after polymerization was taken out from the press plates, and dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (1) was obtained.
The results of evaluation of performance of the obtained absorbent composite (1) are shown in Table 1.
EMBODIMENT 2
The same aqueous monomer solution as used in Embodiment 1 was screen-printed on a polyester nonwoven fabric having 45 g/m 2 of basis weight, and the deposition of the aqueous monomer solution was adjusted to 250 g/m 2 .
This nonwoven fabric applied with aqueous monomer solution was, on both the sides, held for 5 minutes in contact with a pair of facing fluororesin-treated glass fiber endless belts heated to 60° C., and the monomer was polymerized. At this time, the belt interval was set at the same spacing as the thickness of the nonwoven fabric in a stationary state by means of adjuster.
The nonwoven fabric after polymerization was taken out from the belt surfaces, and was dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (2) was obtained.
The results of evaluation of performance of the obtained absorbent composite (2) are shown in Table 1.
EMBODIMENT 3
The same aqueous monomer solution as used in Embodiment 1 was sprayed on a polypropylene nonwoven fabric having 30 g/m 2 of basis weight by a spray nozzle, and the deposition of the aqueous monomer solution was 300 g/m 2 .
This nonwoven fabric applied with the aqueous monomer solution was, on both the sides, held in contact with a pair of facing fluororesin-treated glass fiber endless belts, and the monomer was polymerized by emitting microwaves of 2,450 MHz to the nonwoven fabric for 30 seconds at an output of 400 W at ambient temperature of 25° C. At this time, the belt interval was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of an adjuster.
The nonwoven fabric after polymerization was taken out from the belt surfaces, and was dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (3) was obtained.
The results of evaluation of performance of the obtained absorbent composite (3) are shown in Table 1.
EMBODIMENT 4
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 60 wt. %) having 75 mol % neutralized by potassium hydroxide, 0.2 part by weight of potassium persulfate and 0.005 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
This aqueous monomer solution was screen-printed on a polyethylene nonwoven fabric having 30 g/m 2 of basis weight, and the deposition of the aqueous monomer solution was set at 400 g/m 2 .
This nonwoven fabric applied with aqueous monomer solution was held for 5 minutes between two steel press plates heated to 80° C. through a spacer in the same thickness as the thickness of the nonwoven fabric in a stationary state, and the monomer was polymerized.
The nonwoven fabric after polymerization was taken out from the press plates, and was dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (4) was obtained.
The results of evaluation of performance of the obtained absorbent composite (4) are shown in Table 1.
EMBODIMENT 5
The same aqueous monomer solution as used in Embodiment 4 was gravure-printed in dot pattern on a hydrophilic pulp mat having 45 g/m 2 of basis weight, and the deposition of the aqueous monomer solution was 400 g/m 2 .
This pulp mat applied with aqueous monomer solution was held between a pair of facing fluororesin-treated glass fiber endless belts, and microwaves of 2,450 MHz was emitted to the pulp mat for 30 seconds at an output of 400 W at ambient temperature of 25° C., and the monomer was polymerized. At this time, the belt interval was set so as to be equal to the thickness of the pulp mat in a stationary state by means of an adjuster.
The pulp mat after polymerization was taken out from the belt surfaces, and was dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (5) was obtained.
The results of evaluation of performance of the obtained absorbent composite (5) are shown in Table 1.
EMBODIMENT 6
To 100 parts by weight of 50 wt. % aqueous monomer solution comprising 20 mol % of acrylic acid, 60 mol % of potassium acrylate and 20 mol % of 2-methacryloylethane sulfonic acid potassium salt, 0.5 part by weight of potassium persulfate, 0.003 part by weight of ethyleneglycol diacrylate, and 0.1 part by weight of hydroxyethylcellulose were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
In this aqueous monomer solution, a polypropylene nonwoven fabric having 30 g/m 2 of basis weight was dipped, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed until the deposition of aqueous monomer solution became 150 g/m 2 .
This nonwoven fabric applied with aqueous monomer solution was held for 5 minutes between two steel press plates heated to 80° C. through a spacer in the same thickness as the thickness of the nonwoven fabric in a stationary state, and the monomer was polymerized.
The nonwoven fabric after polymerization was taken out from the press plates, and was dried by emitting microwaves with an output of 600 W for 30 seconds at frequency of 2,450 MHz, and an absorbent composite (6) was obtained.
The results of evaluation of performance of the obtained absorbent composite (6) are shown in Table 1.
EMBODIMENT 7
To 100 parts by weight of 40 wt. % aqueous monomer solution comprising 15 mol % of methacrylic acid, 45 mol % of sodium methacrylate, 20 mol % of 2-acrylamide-2-methylpropane sulfonic acid sodium salt and 20 mol % of acrylamide, 0.2 part by weight of ammonium persulfate and 0.005 part by weight of trimethylol propane triacrylate were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
This aqueous monomer solution was screen-printed on a nonwoven fabric consisting of a conjugated polyethylene-polypropylene fiber and having 40 g/m 2 of basis weight, and the deposition of aqueous monomer solution was set at 200 g/m 2 .
This nonwoven fabric applied with aqueous monomer solution was held for 5 minutes between a pair of facing mirror-finished endless steel belts heated to 80° C., and the monomer was polymerized. At this time, the belt interval was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of an adjuster.
The nonwoven fabric after polymerization was taken out from the belt surfaces, and was dried for 5 minutes in a hot air dryer at 120° C., and an absorbent composite (7) was obtained.
The results of evaluation of performance of the obtained absorbent composite (7) are shown in Table 1.
REFERENCE 1
A reference absorbent composite (1) was obtained in the same manner as in Embodiment 1, except that the monomer was polymerized for 20 minutes by putting the nonwoven fabric on a steel plate heated to 60° C. in a nitrogen atmosphere, instead of polymerizing by placing the nonwoven fabric applied with aqueous monomer solution between two steel press plates.
The results of evaluation of performance of the obtained reference absorbent composite (1) are shown in Table 1.
REFERENCE 2
A reference absorbent composite (2) was obtained in the same manner as in Embodiment 4, except that the monomer was polymerized for 20 minutes by putting the nonwoven fabric on a steel plate heated to 80° C. in a nitrogen atmosphere, instead of polymerizing by placing the nonwoven fabric applied with aqueous monomer solution between two steel press plates.
The results of evaluation of performance of the obtained reference absorbent composite (2) are shown in Table 1.
REFERENCE 3
A reference absorbent composite (3) was obtained in the same manner as in Embodiment 6, except that the monomer was polymerized for 20 minutes by putting the nonwoven fabric on a steel plate heated to 80° C. in a nitrogen atmosphere, instead of polymerizing by placing the nonwoven fabric applied with aqueous monomer solution between two steel press plates.
The results of evaluation of performance of the obtained reference absorbent composite (3) are shown in Table 1.
TABLE 1__________________________________________________________________________ Ratio of Amount of Obtained absorbent absorption residual Drop-off composite (g/g) monomer (ppm) rate (%)__________________________________________________________________________Embodiment 1 Absorbent composite (1) 42 120 2Embodiment 2 Absorbent composite (2) 43 100 2Embodiment 3 Absorbent composite (3) 48 150 6Embodiment 4 Absorbent composite (4) 38 80 1Embodiment 5 Absorbent composite (5) 40 60 4Embodiment 6 Absorbent composite (6) 32 200 3Embodiment 7 Absorbent composite (7) 34 150 4Reference 1 Reference absorbent 36 9800 2 composite (1)Reference 2 Reference absorbent 30 6400 1 composite (2)Reference 3 Reference absorbent 29 9000 3 composite (3)__________________________________________________________________________
Hereinafter are shown the embodiments and references of the continuous manufacturing method of the present invention.
EMBODIMENT 8
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 60 wt. %) with 75 mol % neutralized by potassium hydroxide, 0.2 part by weight of potassium persulfate, and 0.005 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, in this aqueous monomer solution, a polyethylene nonwoven fabric having 30 g/m 2 of basis weight was immersed, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed to set the deposition of aqueous monomer solution to 400 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being, on both the sides, held in contact with a pair of facing fluororesin-treated endless steel belts shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time for pinching with the belt surfaces was 3 minutes, and the polymerization was conducted continuously in this period by maintaining the belt surface temperature at 80° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 1m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer as shown in FIG. 1 to be dried continuously at 120° C., and an absorbent composite (8) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (8) are shown in Table 2.
EMBODIMENT 9
In the apparatus shown in FIG. 1, as the equipment for applying aqueous monomer solution to the substrate, a gravure printing press was installed instead of the immersion tank of aqueous monomer solution, and glass fiber endless belts and a microwave generator with an output of 400 W for generating microwaves at frequency of 2,450 MHz were installed instead of the endless steel belts and steam heaters in the polymerization region.
Using such manufacturing apparatus for absorbent composite, the same aqueous monomer solution as used in Embodiment 8 was gravure-printed in dot pattern on a hydrophilic pulp mat having 45 g/m 2 of basis weight at the deposition of 400 g/m 2 .
This pulp mat applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated glass fiber endless belt surfaces. The clearance C of the belt surfaces was set so as to be equal to the thickness of the pulp mat in a stationary state by means of a clearance adjuster shown in FIG. 2. Polymerization was continuously conducted by emitting microwaves with output of 400 W at frequency of 2,450 MHz to the pulp mat held between the belt surfaces. The ambient temperature during polymerization was 25° C., and the holding time between the belt surfaces was 30 seconds. The moving speed of the pulp mat was 1m per minute.
Sequentially, the pulp mat after polymerization was led into a hot air dryer and was continuously dried at 120° C., and an absorbent composite (9) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (9) are shown in Table 2.
EMBODIMENT 10
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 40 wt. %) with 75 mol % neutralized by sodium hydroxide, 0.2 part by weight of 2,2'-azobis(N,N'-dimethyleneisobutylamidine)dihydrochloride and 0.005 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 3, the aqueous monomer solution was sprayed from spray nozzle to the polypropylene nonwoven fabric having 30 g/m 2 of basis weight so that the deposition may be 250 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between the heat drum roll and the fluororesin-treated glass fiber endless belt surface covering the semicircumference of the drum roll surface shown in FIG. 3. The drum roll peripheral surface and belt surface were set to a clearance equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster and the holding time of the nonwoven fabric between them was 3 minutes, and in this period polymerization was conducted continuously by maintaining the drum roll temperature at 60° C. in a nitrogen atmosphere. The nonwoven fabric moving speed was 0.3m per minute.
Sequentially, the nonwoven fabric after polymerization was led to beneath an infrared lamp shown in FIG. 3, and infrared rays were emitted to dry continuously, and an absorbent composite (10) was obtained. The output of the infrared lamp was 400 W, and the irradiation time was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (10) are shown in Table 2.
EMBODIMENT 11
An absorbent composite (11) was obtained in the same manner as in Embodiment 10, except that a polyester nonwoven fabric having 45 g/m 2 of basis weight was used instead of the polypropylene nonwoven fabric.
The results of evaluation of performance of the obtained absorbent composite (11) are shown in Table 2.
EMBODIMENT 12
An absorbent composite (12) was obtained in the same manner as in Embodiment 8, using the same aqueous monomer solution as used in Embodiment 10, except that the deposition of the aqueous monomer solution to the polyethylene nonwoven fabric was adjusted to 300 g/m 2 .
The results of evaluation of performance of the obtained absorbent composite (12) are shown in Table 2.
EMBODIMENT 13
To 100 parts by weight of 50 wt. % aqueous monomer solution comprising 20 mol % of acrylic acid, 60 mol % of potassium acrylate and 20 mol % of 2-methacryloylethane sulfonic acid potassium salt, 0.5 part by weight of potassium persulfate, 0.003 part by weight of ethylene glycol diacrylate, and 0.1 part by weight of hydroxyethyl cellulose were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, in this aqueous monomer solution, a polypropylene nonwoven fabric having 30 g/m 2 of basis weight was immersed, and the nonwoven fabric entirely impregnated with the aqueous monomer solution was squeezed to adjust the deposition of the aqueous monomer solution to 150 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously by keeping the belt surface temperature at 80° C. in a nitrogen atmosphere. The nonwoven fabric moving speed was 1m per minutes.
Sequentially, the nonwoven fabric after polymerization was led into a drying chamber furnished with a microwave generator with an output of 600 W for generating microwaves at frequency of 2,450 MHz, instead of the hot air dryer in FIG. 1, and it was continuously dried, and an absorbent composite (13) was obtained. The holding time in the drying chamber was 30 seconds.
The results of evaluation of performance of the obtained absorbent composite (13) are shown in Table 2.
EMBODIMENT 14
To 100 parts by weight of 40 wt. % aqueous monomer solution comprising 15 mol % of methacrylic acid, 45 mol % of sodium methacrylate, 20 mol % of 2-acrylamide-2-methylpropane sulfonic acid sodium salt, and 20 mol % of acrylamide, 0.2 part by weight of ammonium persulfate and 0.005 part by weight of trimethylol propane triacylate were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 3, the aqueous monomer solution was sprayed from a spray nozzle to a nonwoven fabric consisting of a conjugated polyethylene-propylene fiber and having 40 g/m 2 of basis weight to the deposition of 200 g/m 2 .
In succession, the nonwoven fabric applied with the aqueous monomer solution was moved as being held between a drum roll and a fluororesin-treated glass fiber endless belt surface covering the semicircumference of the drum roll shown in FIG. 3. The drum roll peripheral surface and belt surface were set to a clearance equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster and the holding time of the nonwoven fabric between them was 3 minutes, and in this period polymerization was conducted continuously while maintaining the drum roll temperature at 80° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 0.3m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer, instead of the drying chamber with an infrared ray lamp in FIG. 3, and was continuously dried at 120° C., and an absorbent composite (14) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (14) are shown in Table 2.
REFERENCE 4
The following operation was performed in the same manner as in Embodiment 8, by using the same apparatus as shown in FIG. 1 except that the upper endless belt 1A was removed.
After immersing a polyethylene nonwoven fabric having 30 g/m 2 of basis weight in the same aqueous monomer solution as that used in Embodiment 8, the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed to adjust the deposition of the aqueous monomer solution to 400 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved by putting on a fluororesin-treated endless steel belt 1B. The holding time on the belt was 20 minutes, and in this period polymerization was conducted continuously by maintaining the belt surface at 80° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 0.15 m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer and was dried continuously at 120° C., and a reference absorbent composite (4) was obtained. The holding time in the dryer was 5 minutes.
The results of evaluation of performance of the obtained reference absorbent composite (4) are shown in Table 2.
REFERENCE 5
The following operation was performed in the same manner as in Embodiment 14, using the same apparatus as shown in FIG. 3, except that the endless belt 14 covering the drum roll 13 was removed and that a hot air dryer was installed instead of the infrared ray lamp.
The same aqueous monomer solution as used in Embodiment 14 was sprayed from a spray nozzle to a nonwoven fabric consisting of a conjugated polyethylene-propylene fiber and having 40 g/m 2 of basis weight to the deposition of 200 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved along the periphery of the drum roll 13. The holding time of the nonwoven fabric in contact with the drum roll periphery was 20 minutes, and in this period polymerization was conducted continuously by maintaining the drum roll temperature at 80° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 0.045m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer, and was continuously dried at 120° C., and a reference absorbent composite (5) was obtained. The holding time in the dryer was 5 minutes.
The results of evaluation of performance of the obtained reference absorbent composite (5) are shown in Table 2.
EMBODIMENT 15
A gravure printing press was installed instead of the immersion tank of aqueous monomer solution as the apparatus for applying the aqueous monomer solution of the substrate in the apparatus shown in FIG. 1.
Using such an apparatus, the same aqueous monomer solution as used in Embodiment 8 was gravure-printed in dot pattern on the rayon nonwoven fabric having 80 g/m 2 of basis weight to the deposition of 400 g/m 2 .
The nonwoven fabric applied with aqueous monomer solution was moved as being held between a pair of facing fluororesin-treated endless steel belt surfaces. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 2 minutes, and in this period polymerization was conducted continuously while maintaining the belt surface temperature at 120° C. in a nitrogen atmosphere, and an absorbent composite (15) was obtained. The moving speed of the nonwoven fabric was 25m per minute.
The results of evaluation of performance of the obtained absorbent composite (15) are shown in Table 2.
EMBODIMENT 16
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 37 wt. %) with 75 mol % neutralized by sodium hydroxide, 0.2 part by weight of sodium persulfate and 0.05 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed to adjust the deposition of the aqueous monomer solution to 80 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved as being held between a pair of facing fluororesin-treated glass fiber endless belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously while maintaining the belt surface temperature at 100° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 1m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (16) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (16) are shown in Table 2.
EMBODIMENT 17
An absorbent composite (17) was obtained by polymerizing in the same manner as in Embodiment 16, except that 0.1 part by weight of trimethylol propane triacylate was used instead of N,N'-methylene bisacrylamide, by depositing the aqueous monomer solution by 25 g/m 2 and maintaining the temperature of glass fiber endless belts at 120° C.
The results of evaluation of performance of the obtained absorbent composite (17) are shown in Table 2.
EMBODIMENT 18
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 35 wt. %) with 75 mol % neutralized by sodium hydroxide, 0.4 part by weight of 2,2'-azobis(2-amidinopropane)dihydrochloride and 0.2 part by weight of polyethylene glycol diacrylate (mean oxyethylene units: 8) were dissolved, and the dissolved oxygen in aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 300 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 120° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 10m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (18) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (18) are shown in Table 2.
EMBODIMENT 19
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 60 wt. %) with 60 mol % neutralized by potassium hydroxide, 0.6 part by weight of 2,2'-azobis(2-amidinopropane) dihydrochloride and 0.09 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 400 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 120° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 1m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (19) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (19) are shown in Table 2.
EMBODIMENT 20
To 100 parts by weight of 40 wt. % aqueous monomer solution comprising 20 mol % of acrylic acid, 60 mol % of sodium acrylate and 20 mol % of ammonium acrylate, 0.2 part by weight of sodium persulfate and 1.5 parts by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 250 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 110° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 10m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (20) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (20) are shown in Table 2.
EMBODIMENT 21
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 40 wt. %) with 60 mol % neutralized by sodium hydroxide, 0.2 part by weight of sodium persulfate and 0.05 part by weight of ethyleneglycol diglycidylether were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 60 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 400 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 1 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 150° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 50m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (21) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (21) are shown in Table 2.
EMBODIMENT 22
To 100 parts by weight of partially neutralized acrylic acid aqueous solution (monomer concentration 40 wt. %) with 85 mol % neutralized by sodium hydroxide, 0.05 part by weight of N,N'-methylene bisacrylamide, 0.2 part by weight of sodium persulfate, and 0.2 part by weight of hydrogen peroxide were dissolved, and 10 parts by weight of hydrophilic pulp fibers with fiber length of 50 μm were added, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 300 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 3 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 120° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 10m per minute.
Sequentially, the nonwoven fabric after polymerization was led into a hot air dryer shown in FIG. 1, and was dried continuously at 120° C., and an absorbent composite (22) was obtained. The holding time in the dryer was 3 minutes.
The results of evaluation of performance of the obtained absorbent composite (22) are shown in Table 2.
EMBODIMENT 23
To 100 parts by weight of aqueous monomer solution (monomer concentration 50 wt. %) comprising 20 mol % of acrylic acid, 65 mol % of sodium acrylate, and 15 mol % of methoxy polyethylene glycol acrylate (mean oxyethylene units: 10), 0.35 part by weight of sodium persulfate and 0.05 part by weight of N,N'-methylene bisacrylamide were dissolved, and the dissolved oxygen in the aqueous monomer solution was removed by nitrogen gas.
Using the apparatus shown in FIG. 1, a polyester nonwoven fabric having 30 g/m 2 of basis weight was immersed in this aqueous monomer solution, and the nonwoven fabric entirely impregnated with aqueous monomer solution was squeezed, and the deposition of aqueous monomer solution was adjusted to 200 g/m 2 .
In succession, the nonwoven fabric applied with aqueous monomer solution was moved while being held between a pair of facing fluororesin-treated endless steel belt surfaces shown in FIG. 1. The clearance C of the belt surfaces was set so as to be equal to the thickness of the nonwoven fabric in a stationary state by means of a clearance adjuster shown in FIG. 2. The holding time between the belt surfaces was 5 minutes, and in this period polymerization was conducted continuously while keeping the belt surface temperature at 100° C. in a nitrogen atmosphere. The moving speed of the nonwoven fabric was 0.5m per minute.
Sequentially, instead of leading the nonwoven fabric after polymerization into the hot air dryer shown in FIG. 1, it was led into a drying chamber equipped with a 3 kW high pressure mercury vapor lamp, and it was dried continuously as being irradiated with ultraviolet rays, and absorbent composite (23) was obtained. The clearance between the nonwoven fabric and mercury vapor lamp was 10 cm, and the holding time was 15 seconds.
The results of evaluation of performance of the obtained absorbent composite (23) are shown in Table 2.
EMBODIMENT 24
An absorbent composite (24) was obtained by drying the nonwoven fabric after polymerization in Embodiment 16 by irradiating with ultraviolet rays in the same manner as in Embodiment 23.
The results of evaluation of performance of the obtained absorbent composite (24) are shown in Table 2.
EMBODIMENT 25
An absorbent composite (25) was obtained in the same manner in Embodiment 16, except that the deposition of the aqueous monomer solution was adjusted to 200 g/m 2 , and that the polymerization was performed by maintaining the belt surface temperature at 120° C.
The results of evaluation of performance of the obtained absorbent composite (25) are shown in Table 2.
REFERENCE 6
A reference absorbent composite (6) was obtained by polymerizing the monomer fixed to the nonwoven fabric in a nitrogen atmosphere while maintaining the belt surface temperature at 120° C., by removing the upper belt 1A in Embodiment 15. The holding time on the belt was 5 minutes, and the moving speed of the nonwoven fabric was 10m per minute.
The results of evaluation of performance of the obtained reference absorbent composite (6) are shown in Table 2.
REFERENCE 7
A reference absorbent composite (7) was obtained by polymerizing the monomer fixed to the nonwoven fabric in a nitrogen atmosphere while maintaining the belt surface temperature at 100° C., by removing the upper belt 1A in Embodiment 16, and drying in a hot air dryer at 120° C. The holding time on the belt and in the dryer was both 5 minutes, and the moving speed of the nonwoven fabric was 0.6m per minute.
The results of evaluation of performance of the obtained reference absorbent composite (7) are shown in Table 2.
REFERENCE 8
A reference absorbent composite (8) was obtained by polymerizing the monomer fixed to the nonwoven fabric in a nitrogen atmosphere while maintaining the belt surface temperature at 150° C., by removing the upper belt 1A in Embodiment 21. The holding time on the belt was 2 minutes, and the moving speed of the nonwoven fabric was 25m per minute.
The results of evaluation of performance of the obtained reference absorbent composite (8) are shown in Table 2.
TABLE 2__________________________________________________________________________ Ratio of Amount of Obtained absorbent absorption residual Drop-off composite (g/g) monomer (ppm) rate (%)__________________________________________________________________________Embodiment 8 Absorbent composite (8) 37 90 2Embodiment 9 Absorbent composite (9) 40 60 3Embodiment 10 Absorbent composite (10) 43 110 7Embodiment 11 Absorbent composite (11) 43 100 6Embodiment 12 Absorbent composite (12) 49 140 4Embodiment 13 Absorbent composite (13) 33 210 3Embodiment 14 Absorbent composite (14) 35 150 4Embodiment 15 Absorbent composite (15) 38 60 4Embodiment 16 Absorbent composite (16) 25 140 1Embodiment 17 Absorbent composite (17) 28 100 1Embodiment 18 Absorbent composite (18) 32 80 1Embodiment 19 Absorbent composite (19) 26 180 2Embodiment 20 Absorbent composite (20) 15 80 3Embodiment 21 Absorbent composite (21) 28 110 2Embodiment 22 Absorbent composite (22) 24 140 3Embodiment 23 Absorbent composite (23) 20 280 4Embodiment 24 Absorbent composite (24) 24 180 1Embodiment 25 Absorbent composite (25) 26 90 2Reference 4 Reference absorbent 29 7200 2 composite (4)Reference 5 Reference absorbent 26 9500 8 composite (5)Reference 6 Reference absorbent 32 8000 5 composite (6)Reference 7 Reference absorbent 24 5500 1 composite (7)Reference 8 Reference absorbent 22 6800 4 composite (8)__________________________________________________________________________ | A method of preparation of an absorbent composite in which an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization is applied to a substrate, and the monomer is polymerized while the substrate to which the aqueous solution is applied is, on both the sides, held in contact with polymerization-inert surfaces facing each other. A continuous manufacturing method includes the sequential steps of continuously passing a substrate through (1) a region applying to the substrate an aqueous solution containing a water-soluble radical polymerization initiator and a water-soluble ethylenically unsaturated monomer which can be converted into an absorbent polymer by polymerization, and (2) a region of polymerizing the monomer while maintaining the substrate, on both the sides, in contact with polymerization-inert surfaces facing each other. | 3 |
FIELD OF THE INVENTION
The invention relates to devices for coating running webs of material, particularly paper webs.
DESCRIPTION OF RELATED TECHNOLOGY
Devices for coating material webs are known which include a cylindrical rotating applicator roll, the surface of which serves to take up a coating composition film and an application device for applying the coating composition film onto the surface of the roll. Such an application device includes a blade which is as wide as the coating machine (i.e., as wide as the length of the cylindrical applicator roll), and forms an acute angle with the surface of the applicator roll. The blade and the surface of the applicator roll define a coating composition sump. A free edge of the blade and the surface of the applicator roll also define an inlet gap. A doctor element is disposed downstream of the blade with respect to the direction of rotation of the applicator roll. The doctor element adjusts the thickness of the coating film on the surface of the applicator roll. An application zone is defined by the inlet gap and the doctor element. The blade, a corresponding blade holder, the doctor element, a corresponding doctor holder, and optionally other walls, partially define an application chamber. The chamber is further defined by retaining shields disposed in the vicinity of the ends of the applicator roll (i.e., at the edges of a web of material being conveyed over the applicator roll).
In coating devices of this type, a web of material is usually coated with the coating composition in an indirect manner. First, the surface of the applicator roll is coated with a coating composition film and then the coating composition film is transported to a deposition point as the applicator roll rotates. At the deposition point, the web to be coated takes up the coating composition film. However, it is also possible to apply the film directly onto the web. In such a method and apparatus, the web to be coated loops about the surface of an applicator roll and travels through the application zone where the coating composition is applied to the web.
To ensure coating of good quality, numerous requirements must be met. The most important requirement is the uniformity of application of the coating composition. The coating should be uniform with respect to the length of the web (i.e., with respect to the direction of travel of the web) as well as to the web width (i.e., with respect to a direction transverse to the direction of travel of the web). Uniform coating requires a coating film of constant thickness as well as constant area weight (which generally are the same). The film should show no irregularities, especially no streaking.
Severe coating problems may arise in such coating devices wherein the application chamber (formed by the blade, the blade holder, the doctor element, the doctor holder and the surface of the applicator roll) receives its inlet flow through a gap which is as wide as the coating machine and is between the blade free edge and the surface of the applicator roll. The coating composition leaves the application chamber between the surface of the roll and the metering doctor in the form of the film. The application chamber is closed at its sides, i.e., in the region of the web edges, by retaining shields. Because the retaining shields are fixed as compared to the applicator roll which rotates, the closure of the application chamber is incomplete and therefore there is a certain leakage of the coating composition on the sides of the chamber defined by the retaining shields. Thus, the coating composition flows from the application chamber toward the outside of the chamber. As a result, in the application chamber in the region of the web edges, the height of the coating composition is somewhat lower than in the remainder of the chamber. This height reduction leads to a reduction of the amount of coating composition available in the region of the web edges and thus to a reduced thickness of the coating composition film in the region of the web edges.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to provide a device according to the invention wherein coating composition film leaves an application chamber in a uniform thickness and, particularly, the coating film is not thinner in the region of the ends of the roll than in the middle region of the roll.
According to the invention, a device for coating a material web includes a rotatable applicator roll having a surface for collecting a film of a coating composition thereon. The roll has a length defined by first and second ends thereof and a middle region disposed between the first and second ends. The device also includes a blade having an edge. The blade is attached to a blade holder and extends along the length of the applicator roll. The blade and the applicator roll surface form an acute angle and define a coating composition sump. The blade edge and the applicator roll surface define an inlet gap. A doctor element attached to a doctor element holder is disposed downstream of the blade with respect to a direction of rotation of the applicator roll. Retaining surfaces of the blade, the blade holder, the doctor element, and the doctor element holder define, at least in part, an application chamber. The device includes at least one of (a) apparatus for regulating flow of the coating composition at the inlet gap of the application chamber to result in the deposition of more coating composition on the applicator roll at the inlet gap in the vicinity of the applicator roll ends than in the vicinity of the middle region of the applicator roll or (b) a flow regulation system wherein at least one of the elements defining the application chamber has outlet openings disposed in the vicinity of the middle region of the applicator roll surface.
Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view of a device according to the invention.
FIG. 2 is an enlarged and partial cross-sectional view of the device of FIG. 1.
FIG. 3 is an enlarged and partial front view of a doctor holder of the device of FIGS. 1 and 2.
FIG. 4 is an enlarged and partial front view of an alternative embodiment of a doctor holder of the device of FIGS. 1 and 2.
FIG. 5 is an enlarged and partial view of the device of FIG. 2.
FIG. 6 is a cross-sectional view of a second embodiment of a device according to the invention.
FIG. 7 is a cross-sectional view of a third embodiment of a device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The figures show coating devices according to the invention wherein means are provided to regulate coating composition flow in order to correct or compensate for the flow in the edge or end regions of a coating application device.
FIG. 1 illustrates a device according to the invention for the indirect coating of a paper web. Two applicator rolls 1 and 2 cooperate with two applicator devices 3 and 4, respectively. Each applicator device includes the following elements: a back wall 3.1, 4.1; a blade holder 3.2, 4.2 with attached blade 3.3, 4.3; and a doctor holder 3.4, 4.4 with attached doctor element 3.5, 4.5. The two rolls 1 and 2 run or rotate in opposite directions as indicated by arrows a and b. The rolls 1 and together define a roll gap g through which a paper web 5 is conveyed in a direction indicated by an arrow c.
Surfaces of the two rolls 1 and 2 rotate or run past sumps 3.7 and 4.7, respectively and then past a free edge of blades 3.3 and 4.3, respectively. A gap i is defined by each blade (3.3 and 4.3) free edge and the surface of the roll (1 and 2) disposed adjacent to the blade edge. (The word adjacent is defined herein as near or close, but not necessarily touching.) The gap i formed by each blade edge and respective roll is as wide as the machine, i.e., the gap extends along the length of each roll 1 and 2 from end to end. The surface of the rolls 1 and 2 then travel past a free edge of the blades 3.3 and 4.3, respectively, and then further to the doctor elements 3.5 and 4.5, respectively. Thus, the surfaces travel past an application chamber defined by the blades 3.3. and 4.3 and the doctor elements 3.5 and 4.5, respectively, wherein a coating composition film of a defined thickness is deposited thereon. The coating composition film is then applied at the roll gap g onto the sides of the paper web 5.
FIG. 2 illustrates a portion of one of the coating application devices 3 according to the invention shown in FIG. 1. In FIG. 2, the application device 3 is shown on a larger scale than what is shown in FIG. 1 to provide a more detailed depiction of the device. The back wall 3.1 is omitted in the embodiment shown in FIG. 2. The application device 3 is disposed at a descending part of the applicator roll 1 so that a substantially horizontal liquid level of the sump 3.7 can develop. FIG. 2 shows the blade holder 3.2 as well as the blade 3.3 connected thereto and supported thereby. A free end f of the blade 3.3 forms the gap i with the surface of the applicator roll 1. The coating composition passes through the gap i from the sump 3.7. An application or retaining chamber 3.6 is defined by the blade 3.3, a portion of the blade holder 3.2, the doctor holder 3.4, the doctor element 3.5 (which is in the form of a doctor roll), a portion of the surface of the applicator roll 1, and a covering plate 3.7.
In the device according to the invention shown in FIG. 2, the doctor holder 3.4 has a plurality of openings in the form of bores 7. According to the invention, a partial amount of the coating composition can leave the application chamber 3.6, preferably through the plurality of bores 7. The bores 7 open into a chamber or collecting channel, which is surrounded by a collecting channel wall 8. The collecting channel wall 8 has a free or open edge 8.1, which is adjustable in placement. The function of the free edge 8.1 is to protect against spray of the coating composition.
The bores 7 in the doctor holder 3.4 provide for the removal of a partial amount of the coating composition from the application chamber 3.6. The bores 7 are shaped and disposed in such a way that, in a middle region along the length of the applicator roll, a relatively large amount of coating composition leaves the application chamber, but relatively little or no coating composition leaves at the edges or ends of the chamber corresponding to edges of a material web being coated.
Two different embodiments of application chambers according to the invention are shown in FIGS. 3 and 4. Both FIGS. 3 and 4 show front views of doctor holders 3.4 and 3.4'", respectively, according to the invention (the front of the holder being defined herein as a face of the holder disposed opposite the portion of the holder through which the coating composition exits. FIG. 3 shows a holder having circular bores 7. The diameters of the bores 7 decrease from the middle portion of the holder toward the edges thereof.
In the embodiment according to the invention shown in FIG. 4, the doctor holder 3.4'" has slitted sections 7.1, 7.2, 7.3 and 7.4. As with the bores 7 illustrated in FIG. 3, the width of the slits in the holder 3.4'" decreases from the middle (slits 7.2. and 7.3) toward the edges (slits 7.1 and 7.4) of the holder 3.4'".
It is also possible to partially or totally cover the openings 7, regardless of whether they are bores or slits by a shutter (not shown). Also, a sliding plate (not shown) can be utilized to adjustably cover either all or a portion of each individual opening. However, a common sliding plate (not shown) may also be provided that has openings corresponding to the openings in the doctor holder. In such an embodiment, the sliding plate can be shifted in such a way that the bores in the doctor holder and the bores in the sliding plates overlap completely or partially.
However, the bores 7, or other openings, can also be provided in any other boundary wall of the application chamber 3.6. Thus, it is conceivable to provide openings in the cover plates 3.7 or in the blade holder 3.2.
It is also possible to provide openings in two or more of the boundary walls (i.e., side retaining shields) of the application chamber 3.6.
However, the purpose of the bores 7 or slits 7.1-7.4 is not only to compensate for out- or over-flow of the coating composition at the edges or ends of the application chamber. Such openings can also provide satisfactory and orderly flow from the sump 3.7 through the gap i, into the application chamber 3.6 and, furthermore, flow from the application chamber 3.6 to the sump 3.7. Thus, "dead corners" and the corresponding danger of undesirable coating composition deposits are avoided.
Also according to the invention, additional flow control from the application chamber can be provided by the inlet gap i being of unequal size along its length, that is, along the length of applicator roll 1 (corresponding to the width of a web being coated). In particular, the width of the gap i increases toward the edges or ends of the applicator roll. As a result, the gap i compensates for the undesired flow of coating composition from the ends of the application chamber.
FIG. 5 shows the gap i of FIGS. 1 and 2 defined by the edge f of the blade 3.3 and the applicator roll 1o FIG. 5 illustrates a view of the gap that is against the flow of the coating composition flowing through the gap i. As can be seen, the free edge f of the blade 3.3 is parabolic in shape so that the gap i width increases toward the ends of the applicator roll 1. The blade 3.3 may also be formed into other shapes by a corresponding displacement mechanism, such as threaded spindles 3.8. The displacement mechanism can, for example, also operate pneumatically or hydraulically. The spindles 3.8 or other displacement mechanism allow the size or width of the inlet gap to be adjustable, providing means for varying or adjusting the amount of coating composition entering in particular regions of the application chamber.
Also according to the invention, the width of an outlet gap o defined by the doctor element 3.5 and the surface of the applicator roll 1 can be of varying sizes across the length thereof. According to the invention, the width of the outlet gap o should increase toward the ends of the applicator roll 1.
Numerous types of doctor elements may be utilized in the device according to the invention. The use of a doctor roll has already been mentioned herein. However, scrapers or other types of fixed doctor elements may also be used. If doctor rolls are utilized, they may be ridged doctors, profiled rods or wire-wound rods.
Similar to the device 3 shown in FIG. 2, an application device 3' according to the invention is shown in FIG. 6. Here too a sump 3.7' is formed between the surface of an applicator roll 1' and a blade 3.3'. An inlet of the device 3' is disposed at a top thereof and is indicated by an arrow 10 which also shows the direction of flow of the coating composition into the device 3'. The coating composition flows around a free edge f' of the blade 3.3' and indicated by an arrow 11. A desired partial amount of the coating composition leaves the application device on both sides of the device as indicated by arrows 12. Thus, only new or fresh coating composition flows into a sump 3.7'. Therefore, entry of foreign particles cannot occur.
An embodiment of a device according to the invention shown in FIG. 7 is similar to the embodiments shown in FIGS. 6 and 2 and includes a particular flow system of coating composition through the device. In a device 3" shown in FIG. 7, a doctor holder 3.4" of the device has a plurality of holes 7" (similar to the device shown in FIG. 2) through which a partial amount of coating composition flows in a direction indicated by an arrow 13 and is captured in a collecting trough 14. Another partial amount of the coating composition flows in a direction indicated by an arrow 12 through slits in a blade holder 3.2", about the device as indicated by an arrow 15, and then re-enters the sump with the new composition feed 10".
In the embodiment of the invention shown in FIG. 7, a partial amount of the coating composition is discharged from the flow system of the device 3" in the direction shown by the arrow 13 while the other portion of the coating composition remains in the system, flowing along in the direction of the arrow 15 and thus becoming a component of an inner flow cycle. The inner flow cycle ensures good flushing of the doctor element 3.5", in order to avoid the adherence of particles onto the doctor element 3.5".
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the invention will be apparent to those skilled in the art. | A device for coating a material web includes a rotatable applicator roll having a surface for collecting a film of a coating composition thereon. The roll has a length defined by first and second ends thereof and a middle region disposed between the first and second ends. The device also includes a blade having an edge. The blade is attached to a blade holder and extends along the length of the applicator roll. The blade and the applicator roll surface form an acute angle and define a coating composition sump. The blade edge and the applicator roll surface define an inlet gap. A doctor element attached to a doctor element holder is disposed downstream of the blade with respect to a direction of rotation of the applicator roll. The blade, the blade holder, the doctor element, and the doctor element holder define, at least in part, an application chamber. At least one of the elements defining the application chamber has bores or other openings for regulating coating composition thickness on the applicator roll. | 3 |
FIELD
[0001] The present disclosure relates generally to a fuel storage system and, more particularly, to a modular fuel storage system for a vehicle.
BACKGROUND
[0002] The use of gaseous fuels, such as hydrogen or compressed natural gas, for vehicles is generally known. Such fuels can represent an alternative to petroleum as a fuel source for motor vehicles, but are generally required to be stored at an elevated or high pressure in a storage tank. Typical storage tanks and their associated mounting systems for compressed gaseous fuels include various components that can raise the cost and complexity of manufacturing an alternative fuel vehicle. In addition, such storage tank systems often result in a loss of interior cabin volume or trunk volume in an automotive vehicle. Thus, there remains a need in the relevant art for a modular fuel storage system that overcomes the aforementioned and other disadvantages.
SUMMARY
[0003] In one form, a modular fuel storage system for a vehicle is provided in accordance with the teachings of the present disclosure. The modular fuel storage system can include a container, a cover, a storage tank and fuel fill and delivery lines. The container can define an interior space therein and the cover can be configured to engage the container to enclose the interior space. The storage tank can be configured to store and selectively deliver a gaseous fuel. The fuel fill and fuel delivery lines can each be fluidly connected to the storage tank. The fill and delivery lines can each have a coupling connector extending external to the container and terminating in a recess formed in an exterior of the container. The modular fuel storage system can be configured to be assembled in the vehicle such that the cover forms a portion of a floor of the vehicle.
[0004] In another form, a vehicle is provided in accordance with the teachings of the present disclosure. The vehicle can include a modular fuel storage system having a container, a cover, first and second storage tanks, fuel fill and delivery lines and an access door. The container can define an interior space therein and the cover can be configured to engage the container to enclose the interior space. The first and second storage tanks can each be configured to store and selectively deliver a gaseous fuel. The fuel fill and delivery lines can each be fluidly connected to the first and second storage tanks. The fuel fill and delivery lines can each have a coupling connector extending external to the container and terminating in a recess formed in an exterior of the container. The access door can be formed in at least a sidewall of the container, and can be removably coupled to the container. An aperture can be formed in a floor of the vehicle and can be positioned between longitudinally extending frame rails of the vehicle and front and rear wheels of the vehicle. The modular fuel storage system can be configured to be positioned in the aperture and fixed to the vehicle such that the cover forms a portion of the floor of the vehicle. The access door can be accessible from an underside of the vehicle to provide access to control features of the storage tanks while the cover remains engaged to the container.
[0005] Further areas of applicability of the teachings of the present disclosure will become apparent from the detailed description, claims and the drawings provided hereinafter, wherein like reference numerals refer to like features throughout the several views of the drawings. It should be understood that the detailed description, including disclosed embodiments and drawings referenced therein, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application or uses. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a partial perspective view of an exemplary modular fuel storage and delivery system shown in association with an exemplary vehicle according to the principles of the present disclosure;
[0007] FIG. 1A is a partial perspective view of the exemplary modular fuel storage and delivery system of FIG. 1 positioned in the exemplary vehicle according to the principles of the present disclosure;
[0008] FIG. 2 is a partial top perspective view of the exemplary modular fuel storage and delivery system of FIG. 1 with a load floor cover removed for clarity of illustration according to the principles of the present disclosure;
[0009] FIG. 3 is an exploded view of the exemplary modular fuel storage and delivery system of FIG. 1 according to the principles of the present disclosure;
[0010] FIG. 4 is a partial bottom perspective view of the exemplary modular fuel storage and delivery system of FIG. 1 with a side access door removed for clarity of illustration according to the principles of the present disclosure;
[0011] FIG. 5 is a partial side view of the exemplary modular fuel storage and delivery system of FIG. 1 with the cover removed and a portion of a container cut away according to the principles of the present disclosure; and
[0012] FIG. 6 is a partial bottom view of the exemplary modular storage and delivery system positioned in the exemplary vehicle according to the principles of the present disclosure.
DETAILED DESCRIPTION
[0013] With initial reference to FIG. 1 , an exemplary modular fuel storage system 10 for storage and delivery of a compressed or high pressure gaseous fuel is shown in association with an exemplary vehicle 14 in accordance with the present teachings. In one exemplary configuration, the gaseous fuel can be compressed natural gas. It will be appreciated, however, that various other gaseous fuels can be utilized with the modular fuel storage system 10 , such as propane or hydrogen.
[0014] In the exemplary configuration illustrated, vehicle 14 is a motor vehicle, such as a minivan, and can include a forward end 18 , a rearward end 22 , a first door opening 26 , a second door opening 30 , and a floor 34 . In this exemplary configuration, the second door opening 30 can be associated with a second row of seating (not specifically shown) in the minivan, and an aperture 40 can be formed in the floor for receipt of the modular fuel storage system 10 , as will be discussed in greater detail below. It should be appreciated that while the discussion will continue with reference to vehicle 14 being a minivan, the modular fuel storage system 10 can be associated with various different vehicle configurations and models.
[0015] In one exemplary configuration, the modular storage system 10 can be positioned in a central location of the vehicle and, when utilized in a minivan, can optionally take the place of stowage tubs typically associated with a collapsible second row of seating. It should be appreciated, however, that the modular storage system 10 can also be positioned at a rearward area of the vehicle. The modular fuel storage system 10 can be received in a manufacturing plant as a pre-certified assembly ready to be positioned in the vehicle thereby eliminating a need for installing various individual components associated with modular storage system 10 . The modular storage system 10 can also be sealed relative to an interior of the vehicle with a sealable cover that forms a portion of the floor 34 of vehicle 14 , as will be discussed in greater detail below.
[0016] With additional reference to FIGS. 2-6 , modular storage system 10 can include a container or tub 54 , a cover 58 and an access door 62 , as generally shown in FIGS. 2-4 . Container 54 can be configured to receive one or more storage tanks, as generally shown in FIGS. 1-5 . In the exemplary configuration illustrated, container 54 can be configured to house two storage tanks, each being of a different size, as will be discussed in greater detail below. Container 54 can include a generally rectangular shape 66 having a longer lateral width than length, where the lateral width can correspond to a cross-car direction, as generally shown in FIGS. 1 and 1A . In this regard, container 54 can include first and second opposed walls or sides 70 , 74 ( FIGS. 1 and 2 ) and third and fourth opposed walls or sides 78 , 82 .
[0017] The container 54 can include an outer perimeter 88 sized to be received in and pass through the aperture 40 of floor 34 , as generally shown in FIG. 1 with reference to FIG. 6 . An upper area or end 92 of container 54 can include a flange 96 extending beyond perimeter 88 and configured to engage a portion of an upper side 102 of floor 34 adjacent aperture 40 when container 54 is positioned therein. A lower side of flange 96 can be sealingly engaged to vehicle floor 34 when container 54 is installed in aperture 40 . In one exemplary configuration, the lower side of flange 96 can be glued to the upper side 102 of floor 34 to sealingly secure container 54 thereto. An upper side 108 of flange 96 can also receive a seal 112 associated with container 54 and/or cover 58 to seal cover 58 to container 54 .
[0018] Container 54 can include a greater height or depth 122 adjacent third side 78 as compared to fourth side 82 so as to facilitate housing storage tanks of different sizes, as generally shown in FIG. 5 where storage tank 126 A positioned relative to third side 78 has a larger diameter than storage tank 126 B positioned relative to fourth side 82 . A plurality of depressions or recessed areas 130 , 134 , 138 can be formed in the exterior of container 54 for facilitating external access to fuel line and coolant line connections, as will be discussed in greater detail below.
[0019] An access aperture 144 can be formed in a side of container 54 , such as the first side 70 shown in FIG. 4 , to facilitate access to operating and control features of the storage tanks 126 A, 126 B while the modular fuel storage system is assembled to vehicle 14 . In this regard, access aperture 144 in connection with removable access door 62 can provide selective access to the operating and control features of tanks 126 A, 126 B without having to remove cover 58 . In one exemplary configuration, access door 62 can form a sealed connection to container 54 when coupled thereto.
[0020] In one exemplary configuration, the access aperture 144 can be formed so as to extend from third side 78 to fourth side 82 and intersect with each of the respective recessed areas 134 , 138 , as shown for example in FIG. 4 . Access door 62 can be sized and shaped to cover aperture 144 and conform to a portion of outer perimeter 88 adjacent aperture 144 , as generally shown in FIG. 4 with reference to FIG. 2 . In the exemplary configuration illustrated, opposed ends 152 of access door 62 can form part of recessed areas 134 , 138 and can engage seals 154 to seal connections to feed and supply lines 162 , 166 that extend from an inside or interior 156 of container 54 into the recessed areas 134 , 138 . The access door 62 can also include a recessed area 158 sized and shaped to provide access to a shut-off valve 174 without having to remove access door 62 , as generally shown in FIG. 2 with reference to FIG. 4 .
[0021] The container 54 can also include a stepped configuration 178 extending generally from the flange 96 along the third side 78 at least partially toward a floor or bottom 182 of container 54 . An intermediate member 186 can extend upward from the stepped configuration 178 so as to be flush or substantially flush with a plane encompassing flange 96 , as generally shown in FIG. 2 . Intermediate member 186 can serve as a structural member to support a portion of seal 112 as well as a pair of bulkheads 190 that can optionally be positioned between intermediate member 186 and respective sides 70 , 74 . A pair of stepped areas 194 can be formed by the bulkheads 190 , intermediate member 186 and associated sides of the container, as also shown in FIG. 2 . These stepped areas 194 can receive optionally integrated seat mounting brackets 202 , as can be seen in FIGS. 2 and 3 .
[0022] It should be appreciated that modular fuel storage system 10 can include container 54 with or without the bulkheads 190 , intermediate member 186 and seat mounting brackets 202 . In a configuration including seat mounting brackets 202 , seal 112 and cover 58 can follow a perimeter 204 established by the sides 70 , 82 , 84 , the bulkheads 190 and the intermediate member 186 , thereby providing access to the seat mounting brackets 202 while sealing an interior of container 54 within perimeter 204 . In a configuration that does not include optional seat mounting brackets 202 , cover 58 and seal 112 can align with perimeter 204 or, alternatively can align with a perimeter 206 ( FIG. 2 ) established by flange 96 . In the latter scenario, the bulkheads 190 , intermediate member 186 and seat mounting brackets 202 can optionally not be included with the modular fuel storage system 10 .
[0023] As briefly discussed above, container 54 can house one or more compressed or high pressure storage tanks, such as tanks 126 A and 126 B. In the exemplary configuration illustrated, two cylindrical tanks 126 A and 126 B can be housed in the interior 156 of container 54 with one of the tanks, 126 A, including a larger diameter than tank 126 B. It will be appreciated, however, that a single tank or multiple tanks of the same or varying widths or diameters can be utilized with container 54 . In the exemplary configuration illustrated, tanks 126 A and 126 B can be positioned contiguous to each other and can extend along a longitudinal length of container 54 , which when positioned in vehicle 14 , can extend cross-vehicle or substantially perpendicular to a longitudinal axis of vehicle 14 .
[0024] As container 54 can be sealed relative to the interior of the vehicle when cover 58 is removably secured thereto, one or more flapper or check valves or vents 210 can be provided in one of the sides 70 , 74 , 78 , 82 of container 54 . In one exemplary configuration illustrated in FIG. 3 , valves/vents 210 can be positioned in side 78 , which is orientated facing rearward when installed in vehicle 14 . This rearward facing orientation can shield or substantially shield valve 210 from road debris and the like during operation of vehicle 14 . It should be appreciated, however, that the valves/vents can also be positioned in container 54 such that they are forward or side facing when storage system 10 is installed in vehicle 14 .
[0025] Tanks 126 A, 126 B can include a retainer assembly 212 configured to support and maintain a predetermined position of tanks 126 A, 126 B in the interior 156 of container 54 and relative to the vehicle 14 . Retainer assembly 212 can include one or more tank strap sets 216 each having a housing 218 with one or more ring-shaped portions 220 sized and shaped to correspond to the width and exterior shape of tanks 126 A, 126 B, as generally shown in FIG. 3 . Each tank strap set 216 can include a first member 226 . The first member 226 can extend from a side of housing 218 and can be configured to be secured to the vehicle 14 adjacent aperture 40 with fasteners 228 . In one exemplary configuration, the first member 226 can be secured to vehicle 14 to thereby removably secure tanks 126 A, 126 B thereto, as generally shown in FIG. 2 with reference to FIGS. 1 and 1A . In this exemplary configuration, the retainer assembly 212 can secure the tanks 126 A, 126 B to the vehicle 14 independent of the container 54 .
[0026] In the exemplary configuration illustrated, retainer assembly 212 can include a pair of tank strap sets 216 each having two ring-shaped portions 220 for engagement with tanks 126 A, 126 B, as shown for example in FIGS. 2 and 3 . A retention and handle assembly 244 can be integrally formed with or coupled to retainer assembly 212 , as generally show in FIGS. 2 and 3 . Retention and handle assembly 244 can include a lower portion 248 and an upper portion 250 . The lower portion 248 can be positioned in a lower space 254 formed between ring-shaped portions 220 such that the lower portion 248 extends substantially along a longitudinal length of tanks 126 A, 126 B and connects to each tank strap set 216 . In the exemplary configuration illustrated, each tank strap set 216 is positioned relative to opposed ends of tanks 126 A, 126 B, as shown for example in FIG. 2 .
[0027] The lower portion 248 can be connected at each end thereof to upper portion 250 via a shoulder bar 256 , as shown for example in FIG. 3 . Upper portion 250 can extend, in one exemplary configuration, along an upper space 258 between tanks 126 A, 126 B from the first side 70 to the second side 74 , as generally shown in FIG. 2 . Tightening the upper portion 250 to the shoulder bar 256 can force the ring shaped portions 220 of tank strap sets 216 downward in space 258 thereby tightening tank strap sets 216 around tanks 126 A, 126 B. In one exemplary configuration, ring-shaped portions 220 can include a rubber liner 260 on an inside thereof configured to engage tanks 126 A, 126 B when secured thereto, as shown for example in FIG. 3 . Upper portion 250 can thus include a longer longitudinal length than lower portion 248 and can be secured to vehicle 14 at its opposed ends, as also shown in FIG. 2 with reference to FIG. 1A . In operation, retention and handle assembly 244 can both serve as a structure to secure tanks 126 A, 126 B to each other and to vehicle 14 (e.g., floor 34 ) via fasteners 228 , as well as a mechanism for carrying tanks 126 A, 126 B to and from container 54 . For example, once the relevant portions of handle assembly 244 are unsecured from vehicle 14 and container 54 (along with first members 226 ), the upper portion 250 of retention and handle assembly 244 can be grasped to lift and remove tanks 126 A, 126 B from container 54 and vehicle 14 . Tanks 126 A, 126 B can then be carried while being coupled to each other via assembly 244 .
[0028] With particular reference to FIG. 5 and continuing reference to FIGS. 1-4 and 6 , tanks 126 A, 126 B can each include a valve 270 operably connected to a pressure regulator 274 . Pressure regulator 274 can be fluidly coupled to both valves 270 along with the feed and supply lines 162 , 166 and a filter system 280 , as generally shown in FIG. 5 with reference to FIG. 3 . Coolant lines 284 can be coupled to the pressure regulator 274 and can be operable to control a temperature of the pressure regulator 274 and associated control components as a result of pressure changes during operation or use of compressed natural gas stored in tanks 126 A, 126 B.
[0029] With particular reference to FIGS. 2 and 4 , the recessed areas 130 , 134 and 138 can be sized and shaped so as to extend beyond the respective coolant lines 284 external connection 264 , supply line 166 external connection 268 , and fill line 162 external connection 272 . This feature can, among other things, serve to protect the external connections 264 , 268 , 272 during transport, vehicle assembly and operation or modular fuel storage system 10 . The modular fuel storage system 10 can be configured as a pre-certified, drop-in modular assembly for its associated vehicle. Necessary connections to vehicle 14 can be accomplished via the external connection capability of container 54 (e.g., external connections 264 , 268 and 272 ). In the exemplary configuration illustrated, external connections 264 , 268 and 272 can be quick-connections for ease of manufacturability and/or serviceability.
[0030] With particular reference to FIGS. 2 , 4 and 6 , modular fuel storage system 10 can include one or more skid plate support straps 290 . Straps 290 can be sized and shaped to conform to an outer shape of container 54 so as to engage at least a portion of sides 78 and 82 and bottom 182 . In the exemplary configuration illustrated, modular fuel storage system 10 can include two straps that extend along bottom 182 and sides 78 , 82 so as to be secured to an underside of floor 34 (or adjacent chassis/frame component), as generally shown in FIG. 4 with reference to FIG. 6 . Straps 290 can be structurally designed to not only aid in supporting container 54 , but also serve as check straps or skid plates to protect the container from any potential under-vehicle hazards. For example, straps 290 can prevent or substantially prevent the bottom 182 of container 54 from being dented or pushed inward due to contact with such under-vehicle hazards.
[0031] In operation, and with particular reference to FIG. 1 , modular fuel storage system 10 can be assembled to minivan vehicle 14 through the second or rear door opening 30 . The modular system 10 can be positioned in aperture 40 from an upper side 102 of floor 34 , as also shown in FIG. 1 . The flange 96 can be sealed to floor 34 and the cover 58 can be semi-permanently sealed to container 54 so as to seal modular system 10 relative to an inside of the passenger compartment of vehicle 14 , while allowing the interior 156 of container 54 to vent to the atmosphere via vents or valves 210 . As discussed above, cover 58 can form a portion of floor 34 of vehicle 14 when modular system 10 is assembled thereto. In one exemplary configuration, the modular system 10 can be installed in the vehicle as a complete, pre-certified assembly with all necessary connections to vehicle components being accessible and handled external to the interior 156 of container 54 .
[0032] The modular fuel storage system 10 can be centrally positioned in vehicle 14 between front and rear axles/wheels 294 , 298 , as generally shown in FIGS. 1 and 6 . In the exemplary configuration illustrated in FIGS. 1 and 6 , the modular system 10 can be positioned between longitudinally extending frame rails 302 , 306 and vehicle cross-members 310 , 314 . In this exemplary configuration, straps 290 can be coupled to cross-members 310 , 314 .
[0033] It should be understood that the mixing and matching of features, elements and/or functions between various examples may be expressly contemplated herein so that one skilled in the art would appreciate from the present teachings that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise above. | A modular fuel storage system can include a container, a cover, a storage tank and fuel fill and delivery lines. The container can define an interior space therein and the cover can be configured to engage the container to enclose the interior space. The storage tank can be configured to store and selectively deliver a gaseous fuel. The fuel fill and fuel delivery lines can each be fluidly connected to the storage tank. The fill and delivery lines can each have a coupling connector extending external to the container and terminating in a recess formed in an exterior of the container. The modular fuel storage system can be configured to be assembled in the vehicle such that the cover forms a portion of a floor of the vehicle. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the field of geophysical exploration. More particularly, the invention relates to an improved, portable apparatus for drilling and underreaming boreholes for containing explosives in land based seismic operations.
[0002] Conventional drill equipment uses flow controlled actuators or bias springs within a drill string to drill and to underream a borehole. Large diameter drill stems manage hydraulic actuators and springs together with associated bearings, gears, cams and guides. Conventional equipment using actuators and springs is illustrated in U.S. Pat. No. 5,351,758 to Henderson et al. (1994), which described a hydraulically actuated mandrel for operating expandable reaming dogs. U.S. Pat. No. 4,893,675 to Skipper (1990) disclosed a section milling tool using pump pressure and a coil spring to operate cutters. U.S. Pat. No. 4,614,242 to Rives (1986) disclosed a mechanical connection between an outer pipe and cutter arms for expanding the cutter arms outwardly to enlarge a borehole. U.S. Pat. No. 4,431,065 to Andrews (1984) disclosed an underreamer having a hydraulic plunger for deploying cuffing arms.
[0003] Seismic shot holes in land based geophysical operations have different requirements unattainable with conventional drilling equipment. Shallow seismic shot holes are slender (less than four inches in diameter) and typically extend less than twenty meters deep. Light duty water or air systems provide a fluid for clearing drill cuttings from the borehole. The narrow cross-section of such boreholes and the associated drilling equipment limits the effectiveness of conventional drill equipment because conventional equipment restricts air flow through the narrow drill pipe diameter. Additionally, seismic shotholes preferably have enlarged sections suitable for installation of explosive material. By enlarging one or more portions downhole in a borehole, extra explosive power can be positioned below the surface to enhance the energy coupling of such explosive power to the geologic formations.
[0004] A significant limitation of seismic borehole drill equipment is the need for portability and deployment by a single person. Seismic surveys cross extreme terrain sometimes inaccessible to trucks and other vehicles, and environmental and economic issues further limit the potential use of conventional drill operations. Seismic boreholes are typically positioned every fifty meters and are carried by hand from one location to the next. The portability of manheld portable drill equipment is limited by the weight and volume of the drill equipment. The time required to setup, drill, break down, and move such equipment determines the overall operating efficiency of the drill system.
[0005] Various slide rail systems offer an alternate method for reaming a drill hole. Slide or guide rail systems have a rail embedded within the borehole diameter to steer the cutting equipment through openings in the main drill stem. Representative reaming bits using guide rails or slide rails are illustrated in U.S. Pat. No. 4,604,818 to Hachiro (1986) which disclosed a pile bore underreaming bucket, and in U.S. Pat. No. 4,407,376 to Inoue (1983) which disclosed an under-reaming pile bore excavator using guide rails to cross the drill pipe axis. Rail type systems are undesirable in slender seismic boreholes because the rails increase fluid or air turbulence within the borehole and thereby lessen the flow available to flush debris from the borehole.
[0006] A need exists for an improved, portable drilling apparatus suitable for drilling and underreaming slender boreholes for seismic operations. The apparatus should be highly portable for use in locations difficult to access and should efficiently create boreholes having the desired shape.
SUMMARY OF THE INVENTION
[0007] The invention provides a portable apparatus for engagement with a drill bit and with a drill mechanism for shaping a seismic borehole wall drilled by the drill bit. The apparatus comprises a drill body having an exterior surface and having a lower end connected to the drill bit, wherein the drill body is selectively moveable by the rotating mechanism. A port extends through the drill body exterior surface, and a reaming bit is movably engaged with the drill body and selectively extendible through the port to contact the borehole wall. A switch is operable by movement of the drill body, and a sleeve is activatable by operation of the switch to move within the drill body and to selectively extend the reaming bit through the port. A cover selectively blocks the port. In various embodiments of the invention, the cover can be integrated within the sleeve, the reaming bit can be retractable within the drill body for operation at another position along the borehole wall, and the force exerted by the reaming bit against the borehole wall can be proportional to a force exerted by the drill body against the drill bit.
[0008] In another embodiment, the invention provides a portable apparatus for drilling a seismic borehole wall in soil which comprises a movable drill body having an exterior surface and a lower end, a drill bit attached to the drill body lower end for forming a borehole wall in the soil, a port through the drill body exterior surface, a reaming bit movably engaged with the drill body and selectively extendible through the port to contact the borehole wall, a switch operable by movement of the drill body, a sleeve activatable by operation of the switch to move within the drill body and to selectively extend the reaming bit through the port, and a cover for selectively blocking the port.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 illustrates a drill body and drill bit operable with a drill mechanism for forming a seismic borehole.
[0010] [0010]FIG. 2 illustrates an initial position of a sleeve and reaming bits relative to a drill body.
[0011] [0011]FIG. 3 illustrates operation of a movable sleeve to initiate reaming bit operation.
[0012] [0012]FIG. 4 illustrates a dish shaped borehole expansion.
[0013] [0013]FIG. 5 illustrates a cylindrical borehole expansion.
[0014] [0014]FIG. 6 illustrates a borehole expansion having a shape controlled by movement of the reaming bits relative to the drill body.
[0015] [0015]FIG. 7 illustrates one configuration for a movable sleeve.
[0016] [0016]FIG. 8 illustrates one configuration of rotatable reaming bits operable with a movable sleeve.
[0017] [0017]FIGS. 9 and 10 illustrate one combination of a switch for selectively operating the movable sleeve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The invention illustrates a highly portable, efficient apparatus for drilling and shaping boreholes used in seismic operations. Referring to FIG. 1, borehole 10 is illustrated in geologic formations 12 and is formed with drill bit 14 rotated or otherwise moved by drive mechanism 16 to form a substantially cylindrical wall defining borehole 10 . Pump 18 injects compressed air or a liquid or other fluid into the interior of drill body 20 to provide a transport mechanism for removing drill cuttings from borehole 10 .
[0019] As shown in FIG. 2, drill body 20 comprises a substantially hollow tubular having exterior surface 22 and interior surface 24 . Although drill body 20 is shown as cylindrical in shape, other configurations can provide the function of transferring steerage and motive forces between drive mechanism 16 and drill bit 14 , and of providing the transport mechanism for conveying the compressed fluid into borehole 10 . Drill body 20 supports one or more reaming bits 26 suspended on axles 28 and movable sleeve 30 positioned within the hollow interior of drill body 20 . FIG. 2 illustrates reaming bits 26 in an initial position during trip time into borehole 10 or while vertical drilling of borehole 10 is conducted. In such initial position, reaming bits 26 are axially and radially aligned with vertical ports 32 through drill body 20 having an alignment dictated by the orientation of axles 28 and the shape of sleeve 30 and of reaming bits 26 . Vertical ports 32 are initially sealed by the upper shutter portion 34 of movable sleeve 30 as shown in FIG. 2. Upper shutter portion 34 provides a cover which prevents leakage of the compressed fluid from within drill body 20 and which prevents intrusion of drill cuttings or other debris contacting exterior surface 22 from entering through vertical ports 32 into the hollow interior of drill body 20 .
[0020] Referring to FIG. 3, as drill body 20 is rotated counterclockwise, lifted and rotated further counterclockwise, a switch (identified below) facilitates movement of sleeve 30 relative to drill body 20 and permits operation of reaming bits 26 relative to drill body 20 and to geologic formations 12 . Upper shutter portion 34 of sleeve 30 opens vertical ports 32 through drill body 20 and permits extension of reaming bits 26 radially outwardly into contact with geologic formations 12 . Such radial extension cuts geologic formations 12 and creates an enlarged portion of borehole 10 .
[0021] As shown in FIG. 4, one representative shape of the borehole 10 enlarged portion can be dish shaped as reaming bits 26 are rotated outwardly. Translation of drill body 20 relative to borehole 10 will cause such dish shapes to be modified to a cylindrical shape as shown in FIG. 5. Various combinations and more complicated shapes for the wall of borehole 10 can be formed with combinations of selective variations of these basic movements, or with different shapes or combinations of reaming bits as shown in FIG. 6.
[0022] The form, configuration and operation of reaming bits 26 can be accomplished in many different ways. One type of reaming bits 26 is illustrated in FIGS. 7 and 8, wherein movable sleeve 30 has upper shutter portion 34 for selectively sealing vertical ports 32 through drill body 20 . Openings 35 through sleeve 30 permit rotatable movement of reaming bits 26 therethrough. Sleeve 30 also has protrusions 36 for contacting cam surfaces 38 of axles 28 . As such contact progresses, reaming bits 26 are rotated outwardly through sleeve openings 35 and ports 32 and into contact with the wall of borehole 10 through geologic formations 12 . Additional movement outwardly and movement of drill body 20 causes reaming bits 26 to cut into the wall of borehole 10 to provide a selected shape.
[0023] [0023]FIGS. 9 and 10 illustrate one combination of a switch for selectively engaging or disengaging movable sleeve 30 relative to drill body 20 . Protruding key or keys 40 can be attached to or formed in drill bit 14 or in a sub such as adapter 42 connected between drill bit 14 and drill body 20 . Keys 40 can be disposed within grooves, channels or slots 44 formed within interior surface 24 of drill body 20 for operation in different directions and sequences suitable for engaging or disengaging operable components such as moveable sleeve 30 . In one embodiment of the invention as illustrated, keys 40 located on an outer wall of adapter 42 are routed such that keys 40 follow slot 44 allowing drill body 20 to slide down the length of adapter 42 toward the bottom of borehole.
[0024] In a preferred embodiment of the invention, drill body 20 slides down adapter 42 a selected distance such as six inches further than the position which was held during the vertical drilling effort. As drill body 20 slides down along adapter 42 , the upper end of adapter 42 makes contact with the lower end of movable sleeve 30 . Movable sleeve 30 then begins to move upward through drill body 20 . As the upper shutter 34 rises past reaming bits 26 each protrusion 36 contacts each reaming bit 26 at the edged portion identified as cam surface 38 causing each reaming bit 26 to rotate outward through the now open vertical ports 32 . As the lower end of each reaming bit 26 clears the bottom of the respective vertical port 32 , the upper end of lower shutter 46 begins to close vertical ports 32 from the bottom end. The axial forces now placed on reaming bits 26 are applied by the upper end of lower shutter 46 and these forces cause reaming bits 26 to extend outward such that each reaming bit 26 bit contacts the wall of borehole 10 . When the reaming bits 26 make contact with the borehole 10 wall the downward sliding of drill body 20 stops as the entire drill string is suspended in borehole 10 by reaming bits 26 . The downward sliding motion of drill body 20 for a selected distance such as the six inches identified above serves as an indicator to the drilling crew that reaming bits 26 are successfully deployed. Axial and radial forces now applied to the drill body 20 will cause reaming bits 26 to cut outwardly and upward. When fully extended, reaming bits 26 can excavate downward.
[0025] For the embodiment of reaming bits 26 identified in FIGS. 7 and 8, a pair of rectangular or cylindrical metal reaming bits 26 are each suspended vertically from a pair of axles 28 which span the diameter of drill body 20 . Cutting edges on each bit 26 are configured to enable each reaming bit 26 to excavate upward, outward, and downward along the borehole 10 wall. Vertical openings such as ports 32 in drill body 20 allow reaming bits 26 to pivot outward beyond exterior surface 22 and into contact with the borehole 10 wall. Moveable sleeve 30 located inside drill body 20 provides integral shutters which position and retain reaming bits 26 inside drill body 20 , and further seals vertical ports 32 from the loss of flushing air or fluid and prevents intrusion of drilling debris until the reaming process is initiated.
[0026] As described above, the reaming process is started with a mechanical matrix or “switch” integral to drill body 20 and to adapter 42 . The switch can comprise a series of slots or grooves machined into the inner wall comprising the base of drill body 20 . A set of protruding keys 40 are fitted or machined into the outer wall of adapter 42 so that drill body 20 is routed to a specified position within the slot-and-key selector matrix relative to the vertical drill bit adapter or sub. For instance, rotating the drill body 20 one quarter turn counterclockwise, then lifting drill body 20 four inches, then rotating another quarter turn counterclockwise, then lowering drill body 20 eight inches would allow the lower end of movable sleeve to contact the upper end of vertical drill bit adapter 42 . After adapter 42 contacts the lower end of movable sleeve 30 and presses upward against moveable sleeve 30 , the reaming process is initiated. When the reaming process is initiated, the upper sleeve shutter 34 rises to open vertical ports 32 and simultaneously actuates cam surface 38 integral to the upper end of each reaming bit 26 . This camming function is executed by cam surface 38 protrusion similar to the shape of a single gear tooth located on the inner wall at the bottom edge of upper shutter 34 , as it contacts and passes by the upper portion of each reaming bit 26 .
[0027] Each cam surface 38 pivots the respective reaming bit 26 outward and upward through the corresponding vertical ports 32 . As the upper shutter 34 moves upward to allow reaming bits 26 to pivot outward and upward, a portion of sleeve 30 identified in FIG. 7 as lower shutter 46 simultaneously rises to block reentry of each reaming bit 26 , to prevent the escape of flushing fluid or air, and to seal against drilling debris intrusion.
[0028] Lower shutter 46 also redirects the downward forces applied to the drill body 20 upward into reaming bits 26 such that either all of the drilling effort is directed to reaming bits 26 of the drilling effort is distributed to reaming bits 26 and vertical drill bit 14 . The force, and consequently the excavation rate applied to reaming bits 26 is controlled by the amount of downward force applied to drill body 20 . The mechanical selector matrix or switch is controlled by the amount of downward force applied to the drill body 20 . The mechanical selector matrix or switch can be configured to allow vertical drilling simultaneously with the reaming process or can disable vertical drilling during the reaming process. As reaming bits 26 expand outward and upward, a bowl or dish shaped cavity can be formed as shown in FIG. 4. Once the reaming bits reach their maximum hole diameter, further drilling can transform the cavity shape from a dish to a cylinder. Reaming bits 26 can be retracted, guided and locked to their original rest position with upper shutter 34 closed by means of the mechanical switching function of the selector matrix or switch. Once reaming bits 26 are retracted and secured, the vertical drilling effort alone can resume if desired, and the expansion process can be restarted at any time to create a series of cavities with a variety of controlled volumes and shapes.
[0029] The length, diameter, shape and cutting edge arrangement of reaming bit or bits 26 can vary depending on the size of the desired cavity, rate of excavation and the general quality of the cavity wall within borehole 10 . A single bit or a plurality of bits 26 can be deployed from the same drill body 20 and more than one reaming bit 26 can be located on a single axle 28 with drill body 20 . Bit axles 28 can be located inline, adjacent the other, or in different combinations to vary the cutting angle and shape of bits 26 . Various functions can be activated directly by the drilling crew to raise, lower and rotate the drill body 20 so that drill body 20 and reaming bit 26 cooperate to provide various cavity shapes.
[0030] The seismic borehole reaming process described in the present invention suspends reaming bits 26 on axles 28 inside drill body 20 which provides a conduit to reaming bits 26 for the drilling forces to be applied to the primary drill stem. Reaming bits 26 are capable of reaming outward from a location within the confines of borehole 10 and are capable of reaming in both upward and downward directions. Moveable sleeve 30 is shaped so that multiple functions are integral to the one-piece sleeve 30 . Such functions include the ability to retain reaming bits 26 in a specific position inside drill body 20 such that bits 26 are always aligned with vertical ports 32 located in drill body 20 . Sleeve 30 releases reaming bits 26 and projects them along a specific path such that they pass through vertical ports 32 of drill body 20 . Sleeve 30 minimizes flushing fluid or air loss through vertical ports 32 during all stages of drilling. Sleeve 32 also retrieves reaming bits 26 in a manner such that reaming bits 26 are returned along a specific path to their original resting position and locked into place and aligned with vertical posts ready to deploy on multiple occasions within the same borehole. Sleeve 30 provides the conduit for all available reaming force from drill body 20 to reaming bits 26 during the outward reaming process and the upward reaming process. Force acting on reaming bits 26 is applied directly from drill body 20 during the downward drilling process.
[0031] The invention is capable of functioning without hydraulic, pneumatic, or electrical power, or without stored energy techniques such as spring functions for actuating any phase of the reaming process. One or more selector matrixes or switches can be deployed to control various processes along the entire drill string. Flow restrictions are minimized because moving sleeve 30 and pivoted reaming bits 26 within the drill body 20 comprise the only impediments to fluid flow. Drill body 20 , sleeve 30 and pivoted bits 26 are integrally shaped to provide direct remote manual control of multiple cycles of guided bit deployment, guided bit retrieval, bit parking and securing, preservation of flushing fluid or flushing air flow, continuous seal against drilling debris intrusion, and direct control of the drilling force applied to reaming bits 26 and drill bit 14 . The invention uniquely provides a system for drilling a vertical borehole and for expanding the borehole diameter at one or more locations along the drilled borehole while maintaining direct control over the radial and axial excavating forces applied and over the size, shape and location of each expanded cavity.
[0032] Although the invention has been described in terms of certain preferred embodiments, it will become apparent to those of ordinary skill in the art that modifications and improvements can be made to the inventive concepts herein without departing from the scope of the invention. The embodiments shown herein are merely illustrative of the inventive concepts and should not be interpreted as limiting the scope of the invention. | An apparatus for shaping boreholes used in seismic operations. A drill body is attached to a drill bit and is movable in axial and rotational directions. Selective operation of the drill body causes a moveable sleeve to operate a reaming bit to extend through a drill body port and into contact with the borehole wall. A cover seals the portion of the port not covered by the reaming bit to prevent loss of a transport fluid within the drill body and to prevent drill cuttings from entering the drill body interior. The cover can be integrated within the movable sleeve or can comprise a separate component. The force exerted by the drill body against the drill bit can be proportional to the force exerted by the reaming bit against the borehole wall. The reaming bit can be operated separately or simultaneously with operation of the drill bit, and can be retracted and reset to perform another shaping operation at a different position within the borehole. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 14/518,568 filed on Oct. 20, 2014, which is a continuation of U.S. application Ser. No. 13/814,336 filed on Feb. 5, 2013, which is a national stage entry under 35 USC §371(b) of International Application No. PCT/US2011/046797, filed Aug. 5, 2011, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/371,433 filed on Aug. 6, 2010, the entire disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
The invention described herein pertains to processes for preparing tubulysins.
BACKGROUND AND SUMMARY OF THE INVENTION
The tubulysins are members of a new class of natural products isolated from myxobacterial species (F. Sasse, et al., J. Antibiot. 2000, 53, 879-885). As cytoskeleton interacting agents, the tubulysins are mitotic poisons that inhibit tubulin polymerization and lead to cell cycle arrest and apoptosis (H. Steinmetz, et al., Chem. Int. Ed. 2004, 43, 4888-4892; M. Khalil, et al., ChemBioChem. 2006, 7, 678-683; G. Kaur, et al., Biochem. J. 2006, 396, 235-242). Tubulysins are extremely potent cytotoxic molecules, exceeding the cell growth inhibition of any clinically relevant traditional chemotherapeutic e.g. epothilones, paclitaxel, and vinblastine. Furthermore, they are potent against multidrug resistant cell lines (A. Dömling, et al., Mol. Diversity 2005, 9, 141-147). These compounds show high cytotoxicity tested against a panel of cancer cell lines with IC 50 values in the low picomolar range; thus, they are of interest as potential anticancer therapeutics.
Tubulysins are described herein. Structurally, tubulysins often include linear tetrapeptoid backbones, including illustrative compounds having formula T
and pharmaceutically acceptable salts thereof;
wherein
Ar 1 is optionally substituted aryl;
R 1 is hydrogen, alkyl, arylalkyl or a pro-drug forming group;
R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl;
R 4 is optionally substituted alkyl or optionally substituted cycloalkyl;
R 3 is optionally substituted alkyl;
R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl;
R 7 is optionally substituted alkyl; and
n is 1, 2, 3, or 4.
Another illustrative group of tubulysins described herein are more particularly comprised of one or more non-naturally occurring or hydrophobic amino acid segments, such as N-methyl pipecolic acid (Mep), isoleucine (Ile),
and analogs and derivative of each of the foregoing. A common feature in the molecular architecture of the more potent natural occurring tubulysins is the acid and/or base sensitive N-acyloxymethyl substituent (or a N, O-acetal of formaldehyde) represented by R2-C(O) in the formula (T).
Another illustrative group of tubulysins described herein are those having formula 1.
Formula 1, Structures of Several Natural Tubulysins
Tubulysin
R A
R 2
A
OH
CH 2 CH(CH 3 ) 2
B
OH
CH 2 CH 2 CH 3
C
OH
CH 2 CH 3
D
H
CH 2 CH(CH 3 ) 2
E
H
CH 2 CH 2 CH 3
F
H
CH 2 CH 3
G
OH
CH═C(CH 3 ) 2
H
H
CH 3
I
OH
CH 3
A total synthesis of tubulysin D possessing C-terminal tubuphenylalanine (R A ═H) (H. Peltier, et al., J. Am. Chem. Soc. 2006, 128, 16018-16019) has been reported. Recently, a modified synthetic protocol toward the synthesis of tubulysin B (R A ═OH) (O. Pando, et al., Org. Lett. 2009, 11, 5567-5569) has been reported. However, attempts to follow the published procedures to provide larger quantities of tubulysins were unsuccessful, being hampered in part by low yields, difficult to remove impurities, the need for expensive chromatographic steps, and/or the lack of reproducibility of several steps. The interest in using tubulysins for anticancer therapeutics accents the need for reliable and efficient processes for preparing tubulysins, and analogs and derivatives thereof. Described herein are improved processes for making natural tubulysins, or analogs or derivatives thereof, including compounds of formula (T) and formula (1).
In one illustrative embodiment of the invention, processes for preparing natural tubulysins, or analogs or derivatives thereof, including compounds of formula (T) and formula (1) are described herein. The processes include one or more steps described herein. In another embodiment, a process is described for preparing a compound of formula B, wherein R 5 and R 6 are as described in the various embodiments herein, such as each being independently selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 8 is C1-C6 n-alkyl; wherein the process comprises the step of treating a compound of formula A with a silylating agent, such as triethylsilyl chloride, and a base, such as imidazole in an aprotic solvent.
It is to be understood that R 5 and R 6 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a compound of formula C, wherein R 5 and R 6 are as described in the various embodiments herein, such as each being independently selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 8 is C1-C6 n-alkyl; and R 2 is as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; wherein the process comprises the step of treating a compound of formula B with a base and a compound of the formula ClCH 2 OC(O)R 2 in an aprotic solvent at a temperature below ambient temperature, such as in the range from about −78° C. to about 0° C.; wherein the molar ratio of the compound of the formula ClCH 2 OC(O)R 2 to the compound of formula B from about 1 to about 1.5.
It is to be understood that R 2 , R 5 and R 6 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a compound of formula D, wherein R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 8 is C1-C6 n-alkyl; R 2 is as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the steps of
a) preparing a compound of formula (E1) where X 1 is a leaving group from a compound of formula E; and
b) treating a compound of formula C under reducing conditions in the presence of the compound of formula E1.
It is to be understood that R 2 , R 5 , R 6 , and R 7 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a compound of formula F, wherein R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 2 is as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating compound D with a hydrolase enzyme.
It is to be understood that R 2 , R 5 , R 6 , and R 7 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a compound of formula G, wherein R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 2 is as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating the silyl ether of compound F with a non-basic fluoride containing reagent.
It is to be understood that R 2 , R 5 , R 6 , and R 7 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a compound of formula H, wherein R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 2 and R 4 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating a compound of formula G with an acylating agent of formula R 4 C(O)X 2 , where X 2 is a leaving group.
It is to be understood that R 2 , R 4 , R 5 , R 6 , and R 7 may each include conventional protection groups on the optional substituents.
In another embodiment, a process is described for preparing a tubulysin of formula (T), wherein Ar 1 is optionally substituted aryl; R 1 is hydrogen, optionally substituted alkyl, optionally substituted arylalkyl or a pro-drug forming group; R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; R 3 is optionally substituted alkyl; R 2 and R 4 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of forming an active ester intermediate from a compound of formula H; and reacting the active ester intermediate with a compound of the formula I to give a compound of the formula T.
It is to be understood that Ar 1 , R 1 , R 2 , R 4 , R 5 , R 6 , and R 7 may each include conventional protection groups on the optional substituents.
DETAILED DESCRIPTION
In one embodiment, a process is described for preparing a compound of formula B, wherein R 5 and R 6 are as described in the various embodiments herein, such as being selected from optionally substituted alkyl or optionally substituted cycloalkyl; and R 8 is C1-C6 n-alkyl; wherein the process comprises the step of treating a compound of formula A with triethylsilyl chloride and imidazole in an aprotic solvent.
In the previously reported preparations of the intermediate silyl ether of formula 2, use of a large excess of triethylsilyl trifluoromethylsulfonate (TESOTf) and lutidine is described (see, for example, Peltier, et al., 2006). It was found that the reported process makes it necessary to submit the product of the reaction to a chromatographic purification step. Contrary to that reported, it has been surprisingly discovered herein that the less reactive reagent TESC1 may be used. It has also been surprisingly discovered herein that although TESC1 is a less reactive reagent, it may nonetheless be used in nearly stoichiometric amounts in the processes described herein. It is appreciated herein that the use of the less reactive TESC1 may also be advantageous when the process is performed on larger scales, where higher reactivity reagents may represent a safety issue. It has also been discovered that the use of TESC1 in nearly stoichiometric amounts renders the chromatographic purification step unnecessary. In an alternative of the embodiment, the process is performed without subsequent purification. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 5 is isopropyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 6 is sec-butyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 8 is methyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, the silyl ether is TES.
In an illustrative example of the processes described herein, a process for preparing the silyl ether 2 in high yield is described wherein compound 1 is treated with 1.05 equivalent of TESC1 and 1.1 equivalent of imidazole.
In one alternative of the foregoing example, the compound 2 is nor purified y chromatography.
In another embodiment, a process is described for preparing a compound of formula C, wherein R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 8 is C1-C6 n-alkyl; and R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; wherein the process comprises the step of treating a compound of formula B with from about 1 equivalent to about 1.5 equivalent of base and from about 1 equivalent to about 1.5 equivalent of a compound of the formula ClCH 2 OC(O)R 2 in an aprotic solvent at a temperature from about −78° C. to about 0° C.
In another embodiment, the process of the preceding embodiment is described wherein the compounds of formulae B and C have the stereochemistry shown in the following scheme for B′ and C′.
In another illustrative embodiment, the process of any one of the preceding embodiments is described wherein about 1 equivalent to about 1.3 equivalent of a compound of the formula ClCH 2 OC(O)R 2 is used. In another illustrative example, the process of any one of the preceding embodiments is described, wherein about 1.2 equivalent of a compound of the formula ClCH 2 OC(O)R 2 is used. In another illustrative example, the process of any one of the preceding embodiments is described wherein R 2 is n-propyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 2 is CH 2 CH(CH 3 ) 2 , CH 2 CH 2 CH 3 , CH 2 CH 3 , CH═C(CH 3 ) 2 , or CH 3 .
In an illustrative example of the processes described herein, a process for preparing the N,O-acetal 3 is described. In another illustrative example, compound 2 is treated with 1.1 equivalent of potassium hexamethyldisilazane (KHMDS) and 1.2 equivalent of chloromethyl butanoate in a nonprotic solvent at about −45° C. In another illustrative example, the product formed by any of the preceding examples may be used without chromatographic purification.
In another embodiment, a process is described for preparing a compound of formula D, wherein R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and cycloalkyl; R 8 is C1-C6 n-alkyl; R 2 is selected from the group consisting of optionally substituted alkyl and cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the steps of
a) preparing a compound of formula (E1) where X 1 is a leaving group from a compound of formula E; and
b) treating a compound of formula C under reducing conditions with the compound of formula E1.
In one illustrative example, a mixture of compound 3 and the pentafluorophenyl ester of D-N-methyl-pipecolic acid is reduced using H 2 and a palladium-on-charcoal catalyst (Pd/C) to yield compound 4. It has been discovered herein that epimerization of the active ester of pipecolic acid can occur during reaction or during its preparation or during the reduction under the previously reported reaction conditions. For example, contrary to prior reports indicating that epimerization does not occur (see, for example, Peltier, 2006), upon repeating those reported processes on a larger scale it was found here that substantial amounts of epimerized compounds were formed. In addition, it was discovered herein that substantial amounts of rearrangement products formed by the rearrangement of the butyryl group to compound 8 were formed using the reported processes. Finally, it was discovered herein that the typical yields of the desired products using the previously reported processes were only about half of that reported. It has been discovered herein that using diisopropylcarbodiimide (DIC) and short reaction times lessens that amount of both the unwanted by-product resulting from the epimerization reaction and the by-product resulting from the rearrangement reaction. In another alternative of the foregoing embodiments, and each additional embodiment described herein, n is 3. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 7 is methyl.
In one illustrative example, it was found that limiting the reaction time for the preparation of pentafluorophenyl D-N-methyl-pipecolate to about 1 hour lessened the formation of the diastereomeric tripeptide 9. It has also been discovered that using dry 10% Pd/C as catalyst, rather than a more typically used wet or moist catalyst, lessens the amount of epimer 9 formed during the reduction. It has also been discovered that using dry 10% P/C and/or shorter reaction times also lessens the formation of rearranged amide 8.
It has been previously reported that removal of the protecting group from the secondary hydroxyl group leads to an inseparable mixture of the desired product 5 and a cyclic O,N-acetal side-product as shown in the following scheme.
Further, upon repeating the reported process, it has been discovered herein that removal of the methyl ester using basic conditions, followed by acetylation of the hydroxyl group leads to an additional previously unreported side-product, iso-7. That additional side-product is difficult to detect and difficult to separate from the desired compound 7. Without being bound by theory, it is believed herein that iso-7 results from rearrangement of the butyrate group from the N-hydroxymethyl group to the secondary hydroxyl group, as shown below.
It has been discovered that reordering the two deprotection steps and using different conditions for each deprotection reaction results in improved yields of compounds of formula H, such as compound 7, after introduction of the R 4 CO group on the secondary hydroxyl group, as further described below.
In another embodiment, a process is described for preparing a compound of formula F, wherein R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating compound D with a hydrolase enzyme.
In another embodiment, the preceding process wherein the treating step comprises adding a solution of compound D in a water miscible solvent to a buffered solution containing the hydrolase enzyme at a rate which minimizes precipitation of the ester. In another embodiment the ester is added over a period of from about 24 hours to about 100 hours. In another embodiment the ester is added over a period of from about 48 hours to about 100 hours. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 8 is methyl. In another embodiment, the embodiment of any one of the preceding embodiments wherein the hydrolase enzyme is an esterase is described. In another embodiment, the embodiment of any of the preceding embodiments wherein the esterase is a pig liver esterase is described.
In an illustrative example, a solution of compound 4 in dimethyl sulfoxide (DMSO) is added over a period of 90 hours, to a buffered solution of pig liver esterase. In another illustrative example, the buffer is a phosphate buffer. In another illustrative example, the solution of the enzyme has a pH of 6.5 to 8.5. In another illustrative, example the solution of the enzyme has a pH of 7.4 to 7.8. It is appreciated that the buffering material used can be any buffer compatible with the hydrolase enzyme used to remove the ester.
In another embodiment, a process is described for preparing a compound of formula G, wherein R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating the silyl ether of compound F with a non-basic fluoride reagent. It has been discovered herein that use of basic conditions can lead to the production of a by-product arising from the rearrangement of the ester group to give compound G′.
In an illustrative example, compound 6 is treated with Et 3 N.3HF to cleave the TES-ether in the preparation of the corresponding alcohol 6′. It is to be understood that other non-basic fluoride reagents to cleave the silyl ether of compounds F may be used in the methods and processes described herein, including but not limited to pyridine.HF, and the like to cleave the TES-ether.
In another embodiment, a process is described for preparing a compound of formula H, wherein R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 2 and R 4 are independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the step of treating a compound of formula G with an acylating agent of formula R 4 C(O)X 2 , where X 2 is a leaving group. It is appreciated that the resulting product may contain varying amounts of the mixed anhydride of compound H and R 4 CO 2 H. In another embodiment, the process described in the preceding embodiment further comprises the step of treating the reaction product with water to prepare H, free of or substantially free of anhydride. In another embodiment, the process of the preceding embodiments wherein X 2 is R 4 CO 2 , is described. In another embodiment, the process of any one of the preceding embodiments wherein R 4 is C1-C4 alkyl is described. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 4 is methyl. In another embodiment, the process of any one of the preceding embodiments wherein R 6 is sec-butyl is described. In another embodiment, the process of any one of the preceding embodiments wherein R 7 is methyl is described. In another embodiment, the process of any one of the preceding embodiments wherein R 5 is iso-propyl is described.
In an illustrative example, compound 6′ is treated with acetic anhydride in pyridine. It has been discovered herein that shortening the time for this step of the process improves the yield of compound H by limiting the amount of the previously undescribed alternative acylation side products, such as formula 7a that are formed. It is appreciated that the resulting product may contain varying amounts of the mixed anhydride of 7 and acetic acid. In another embodiment, treatment of the reaction product resulting from the preceding step with water in dioxane yields compound 7, free of or substantially free of anhydride. It is to be understood that other solvents can be substituted for dioxane in the hydrolysis of the intermediate mixed anhydride. Alternatively, the step may be performed without solvent.
In another embodiment, a process is described for preparing a tubulysin T, wherein Ar 1 is optionally substituted aryl; R 1 is hydrogen, alkyl, arylalkyl or a pro-drug forming group; R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 3 is optionally substituted alkyl; R 2 and R 4 are independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; and R 7 is optionally substituted alkyl; wherein the process comprises the steps of
c) forming an active ester intermediate from a compound of formula H; and
d) reacting the active ester intermediate with a compound of the formula I.
It has been discovered herein that when the free acid of I (where R 1 is hydrogen) is used in this step as reported previously, the desired product T can react with additional amino acid I to form poly amino acid side-products containing multiple copies of the amino acid I in a side reaction not previously reported. It has also been discovered herein that removal of excess activate ester forming agent prior to addition of the compound I, lessens or eliminates this side reaction to acceptable levels. In one embodiment, compound H is treated with an excess amount of active ester forming agent and pentafluorophenol to form the pentafluorophenol ester of compound H, followed by removal of the excess active ester forming agent prior to the addition of compound I. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is 4-substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is R A -substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is 4-hydroxyphenyl, or a hydroxyl protected form thereof. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 3 is methyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 1 is hydrogen.
In an illustrative example, compound 7 is treated with an excess amount of a polymeric version of a carbodiimide and pentafluorophenol to form the pentafluorophenyl ester of 7, the polymeric carbodiimide is removed by filtration; and amino acid (S)-tubutyrosine is added to the solution to yield tubulysin B. In another embodiment, the process of any one of the preceding embodiments wherein the polymeric carbodiimide is polystyrene-CH 2 —N═C═N-cyclohexane (PS-DCC) is described.
In another embodiment, a compound having formula D, wherein the compound is free of or substantially free of a compound having formula C-1 is described, where in R 2 , R 5 , R 6 , R 7 , and R 8 are as described in any of the embodiments described herein. Without being bound by theory, it is believed herein that compounds C-1 are formed from the corresponding compounds C via an acyl transfer.
In another embodiment, compound 4, free of or substantially free of compound 8 and/or compound 9 is described. In another embodiment, an optically pure form of compound 4 is formed.
In another embodiment, a compound H, wherein the compound H is free of or substantially free, of a compound having the formula Oxazine-2 is described.
In another embodiment, a compound F is described wherein R 2 , R 5 , R 6 , R 7 and R 8 are as described in the any of the embodiments described herein.
In another embodiment, the compound having formula 6 is described.
In another embodiment a compound G, where the compound is free of or substantially free of a compound G′ is described, wherein R 2 , R 5 , R 6 , and R 7 are as described in any of the embodiments described herein.
In another embodiment, compound 6′ is described, wherein compound 6′ is free of or substantially free of the isomer of G′ shown below
In another embodiment, compound 7 is described, wherein compound 7 is free of or substantially free of compound 7a is described
In another embodiment, a compound H is described wherein R 4 is Me and R 2 , R 5 , R 6 , and R 7 are as described in any of the embodiments described herein; and the compound H is free of or substantially free of the compound H wherein R 4 and R 2 are both Me.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 5 is isopropyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 6 is sec-butyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 8 is methyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 2 is CH 2 CH(CH 3 ) 2 , CH 2 CH 2 CH 3 , CH 2 CH 3 , CH═C(CH 3 ) 2 , or CH 3 .
In another alternative of the foregoing embodiments, and each additional embodiment described herein, n is 3.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 7 is methyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 8 is methyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 4 is methyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is 4-substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is R A -substituted phenyl. In another alternative of the foregoing embodiments, and each additional embodiment described herein, Ar 1 is 4-hydroxyphenyl, or a hydroxyl protected form thereof.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 3 is methyl.
In another alternative of the foregoing embodiments, and each additional embodiment described herein, R 1 is hydrogen.
Illustrative embodiments of the invention are further described by the following enumerated clauses: 1. A process for preparing a compound of the formula
or a pharmaceutically acceptable salt thereof; wherein Ar 1 is optionally substituted aryl; R 1 is hydrogen, alkyl, arylalkyl or a pro-drug forming group; R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 3 is optionally substituted alkyl; R 4 is optionally substituted alkyl or optionally substituted cycloalkyl; R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 7 is optionally substituted alkyl; and n is 1, 2, 3, or 4; wherein the process comprises the step of treating a compound of formula A with triethylsilyl chloride and imidazole in an aprotic solvent, where R 8 is C1-C6 unbranched alkyl
or the step of treating a compound of formula B with a base and a compound of the formula ClCH 2 OC(O)R 2 in an aprotic solvent at a temperature from about −78° C. to about 0° C.; wherein the molar ratio of the compound of the formula ClCH 2 OC(O)R 2 to the compound of formula B from about 1 to about 1.5, where R 8 is C1-C6 unbranched alkyl
or the steps of a) preparing a compound of formula (E1), where X 1 is a leaving group, from a compound of formula E
and b) treating a compound of formula C under reducing conditions in the presence of the compound of formula E1, where R 8 is C1-C6 unbranched alkyl
or the step of treating compound D with a hydrolase enzyme, where R 8 is C1-C6 unbranched alkyl
or the step of treating the silyl ether of compound F with a non-basic fluoride reagent
or the step of treating a compound of formula G with an acylating agent of formula R 4 C(O)X 2 , where X 2 is a leaving group
or the steps of c) forming an active ester intermediate from a compound of formula H
and d) reacting the active ester intermediate with a compound of the formula I
or combinations thereof. 1a. The process of clause 1 wherein R 4 is optionally substituted alkyl. 2. The process of clause 1 or 1a comprising the step of treating a compound of formula A with triethylsilyl chloride and imidazole in an aprotic solvent, where R 8 is C1-C6 unbranched alkyl
3. The process of clause 1 or 1a comprising the step of treating a compound of formula B with a base and a compound of the formula ClCH 2 OC(O)R 2 in an aprotic solvent at a temperature from about −78° C. to about 0° C.; wherein the molar ratio of the compound of the formula ClCH 2 OC(O)R 2 to the compound of formula B from about 1 to about 1.5, where R 8 is C1-C6 unbranched alkyl
4. The process of clause 1 or 1a comprising the steps of a) preparing a compound of formula (E1), where X 1 is a leaving group, from a compound of formula E
and b) treating a compound of formula C under reducing conditions in the presence of the compound of formula E1, where R 8 is C1-C6 unbranched alkyl
5. The process of clause 1 or 1a comprising the step of treating compound D with a hydrolase enzyme, where R 8 is C1-C6 unbranched alkyl
6. The process of clause 1 or 1a comprising the step of treating a compound of formula G with an acylating agent of formula R 4 C(O)X 2 , where X 2 is a leaving group
7. The process of clause 1 or 1a comprising the steps of c) forming an active ester intermediate from a compound of formula H
and d) reacting the active ester intermediate with a compound of the formula I
8. The process of any one of clauses 1 to 7 or 1a wherein R 1 is hydrogen, benzyl, or C1-C4 alkyl. 9. The process of any one of the preceding clauses wherein R 1 is hydrogen. 10. The process of any one of the preceding clauses wherein R 2 is C1-C8 alkyl or C3-C8 cycloalkyl. 11. The process of any one of the preceding clauses wherein R 2 is n-butyl. 12. The process of any one of the preceding clauses wherein R 3 is C1-C4 alkyl. 13. The process of any one of the preceding clauses wherein R 3 is methyl. 14. The process of any one of the preceding clauses wherein Ar 1 is phenyl or hydroxyphenyl. 15. The process of any one of the preceding clauses wherein Ar 1 is 4-hydroxyphenyl. 16. The process of any one of the preceding clauses wherein R 4 is C1-C8 alkyl or C3-C8 cycloalkyl. 17. The process of any one of the preceding clauses wherein R 4 is methyl. 18. The process of any one of the preceding clauses wherein R 5 is branched C3-C6 or C3-C8 cycloalkyl. 19. The process of any one of the preceding clauses wherein R 5 is iso-propyl. 20. The process of any one of the preceding clauses wherein R 6 is branched C3-C6 or C3-C8 cycloalkyl. 21. The process of any one of the preceding clauses wherein R 5 is sec-butyl. 22. The process of any one of the preceding clauses wherein R 7 is C1-C6 alkyl. 23. The process of any one of the preceding clauses wherein R 7 is methyl. 24. The process of any one of the preceding clauses wherein R 2 is CH 2 CH(CH 3 ) 2 , CH 2 CH 2 CH 3 , CH 2 CH 3 , CH═C(CH 3 ) 2 , or CH 3 , 25. The process of any one of the preceding clauses wherein An is substituted phenyl. 26. The process of any one of the preceding clauses wherein Ar 1 is 4-substituted phenyl. 27. The process of any one of the preceding clauses wherein Ar 1 is R A -substituted phenyl. 28. The process of any one of the preceding clauses wherein Ar 1 is 4-hydroxyphenyl, or a hydroxyl protected form thereof.
It is to be understood that as used herein, the term tubulysin refers both collectively and individually to the naturally occurring tubulysins, and the analogs and derivatives of tubulysins. Illustrative examples of a tubulysin are shown in Table 1.
As used herein, the term tubulysin generally refers to the compounds described herein and analogs and derivatives thereof. It is also to be understood that in each of the foregoing, any corresponding pharmaceutically acceptable salt is also included in the illustrative embodiments described herein.
It is to be understood that such derivatives may include prodrugs of the compounds described herein, compounds described herein that include one or more protection or protecting groups, including compounds that are used in the preparation of other compounds described herein.
In addition, as used herein the term tubulysin also refers to prodrug derivatives of the compounds described herein, and including prodrugs of the various analogs and derivatives thereof. In addition, as used herein, the term tubulysin refers to both the amorphous as well as any and all morphological forms of each of the compounds described herein. In addition, as used herein, the term tubulysin refers to any and all hydrates, or other solvates, of the compounds described herein.
It is to be understood that each of the foregoing embodiments may be combined in chemically relevant ways to generate subsets of the embodiments described herein. Accordingly, it is to be further understood that all such subsets are also illustrative embodiments of the invention described herein.
The compounds described herein may contain one or more chiral centers, or may otherwise be capable of existing as multiple stereoisomers. It is to be understood that in one embodiment, the invention described herein is not limited to any particular stereochemical requirement, and that the compounds, and compositions, methods, uses, and medicaments that include them may be optically pure, or may be any of a variety of stereoisomeric mixtures, including racemic and other mixtures of enantiomers, other mixtures of diastereomers, and the like. It is also to be understood that such mixtures of stereoisomers may include a single stereochemical configuration at one or more chiral centers, while including mixtures of stereochemical configuration at one or more other chiral centers.
Similarly, the compounds described herein may include geometric centers, such as cis, trans, (E)-, and (Z)-double bonds. It is to be understood that in another embodiment, the invention described herein is not limited to any particular geometric isomer requirement, and that the compounds, and compositions, methods, uses, and medicaments that include them may be pure, or may be any of a variety of geometric isomer mixtures. It is also to be understood that such mixtures of geometric isomers may include a single configuration at one or more double bonds, while including mixtures of geometry at one or more other double bonds.
As used herein, the term aprotic solvent refers to a solvent which does not yield a proton to the solute(s) under reaction conditions. Illustrative examples of nonprotic solvents are tetrahydrofuran (THF), 2,5-dimethyl-tetrahydrofuran, 2-methyl-tetrahydrofuran, tetrahydropyran, diethyl ether, t-butyl methyl ether, dimethyl formamide, N-methylpyrrolidinone (NMP), and the like. It is appreciated that mixtures of these solvents may also be used in the processes described herein.
As used herein, an equivalent amount of a reagent refers to the theoretical amount of the reagent necessary to transform a starting material into a desired product, i.e. if 1 mole of reagent is theoretically required to transform 1 mole of the starting material into 1 mole of product, then 1 equivalent of the reagent represents 1 mole of the reagent; if X moles of reagent are theoretically required to convert 1 mole of the starting material into 1 mole of product, then 1 equivalent of reagent represents X moles of reagent.
As used herein, the term active ester forming agent generally refers to any reagent or combinations of reagents that may be used to convert a carboxylic acid into an active ester.
As used herein, the term active ester generally refers to a carboxylic acid ester compound wherein the divalent oxygen portion of the ester is a leaving group resulting in an ester that is activated for reacting with compounds containing functional groups, such as amines, alcohols or sulfhydryl groups. Illustrative examples of active ester-forming compounds are N-hydroxysuccinimide, N-hydroxyphthalimide, phenols substituted with electron withdrawing groups, such as but not limited to 4-nitrophenol, pentafluorophenol, N,N′-disubstituted isoureas, substituted hydroxyheteroaryls, such as but not limited to 2-pyridinols, 1-hydroxybenzotriazoles, 1-hydroxy-7-aza-benzotriazoles, cyanomethanol, and the like. Illustratively, the reaction conditions for displacing the active ester with a compound having an amino, hydroxy or thiol group are mild. Illustratively, the reaction conditions for displacing the active ester with a compound having an amino, hydroxy or thiol group are performed at ambient or below ambient temperatures. Illustratively, the reaction conditions for displacing the active ester with a compound having an amino, hydroxy or thiol group are performed without the addition of a strong base. Illustratively, the reaction conditions for displacing the active ester with a compound having an amino, hydroxy or thiol group are performed with the addition of a tertiary amine base, such as a tertiary amine base having a conjugate acid pKa of about 11 or less, about 10.5 or less, and the like.
As used herein, the term “alkyl” includes a chain of carbon atoms, which is optionally branched. As used herein, the term “alkenyl” and “alkynyl” includes a chain of carbon atoms, which is optionally branched, and includes at least one double bond or triple bond, respectively. It is to be understood that alkynyl may also include one or more double bonds. It is to be further understood that in certain embodiments, alkyl is advantageously of limited length, including C 1 -C 24 , C 1 -C 12 , C 1 -C 8 , C 1 -C 6 , and C 1 -C 4 . It is to be further understood that in certain embodiments alkenyl and/or alkynyl may each be advantageously of limited length, including C 2 -C 24 , C 2 -C 12 , C 2 -C 8 , C 2 -C 6 , and C 2 -C 4 . It is appreciated herein that shorter alkyl, alkenyl, and/or alkynyl groups may add less lipophilicity to the compound and accordingly will have different pharmacokinetic behavior. Illustrative alkyl groups are, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, 3-pentyl, neopentyl, hexyl, heptyl, octyl and the like.
As used herein, the term “cycloalkyl” includes a chain of carbon atoms, which is optionally branched, where at least a portion of the chain in cyclic. It is to be understood that cycloalkylalkyl is a subset of cycloalkyl. It is to be understood that cycloalkyl may be polycyclic. Illustrative cycloalkyl include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, 2-methylcyclopropyl, cyclopentyleth-2-yl, adamantyl, and the like. As used herein, the term “cycloalkenyl” includes a chain of carbon atoms, which is optionally branched, and includes at least one double bond, where at least a portion of the chain in cyclic. It is to be understood that the one or more double bonds may be in the cyclic portion of cycloalkenyl and/or the non-cyclic portion of cycloalkenyl. It is to be understood that cycloalkenylalkyl and cycloalkylalkenyl are each subsets of cycloalkenyl. It is to be understood that cycloalkyl may be polycyclic. Illustrative cycloalkenyl include, but are not limited to, cyclopentenyl, cyclohexylethen-2-yl, cycloheptenylpropenyl, and the like. It is to be further understood that chain forming cycloalkyl and/or cycloalkenyl is advantageously of limited length, including C 3 -C 24 , C 3 -C 12 , C 3 -C 8 , C 3 -C 6 , and C 5 -C 6 . It is appreciated herein that shorter alkyl and/or alkenyl chains forming cycloalkyl and/or cycloalkenyl, respectively, may add less lipophilicity to the compound and accordingly will have different pharmacokinetic behavior.
As used herein, the term “heteroalkyl” includes a chain of atoms that includes both carbon and at least one heteroatom, and is optionally branched. Illustrative heteroatoms include nitrogen, oxygen, and sulfur. In certain variations, illustrative heteroatoms also include phosphorus, and selenium. As used herein, the term “cycloheteroalkyl” including heterocyclyl and heterocycle, includes a chain of atoms that includes both carbon and at least one heteroatom, such as heteroalkyl, and is optionally branched, where at least a portion of the chain is cyclic. Illustrative heteroatoms include nitrogen, oxygen, and sulfur. In certain variations, illustrative heteroatoms also include phosphorus, and selenium. Illustrative cycloheteroalkyl include, but are not limited to, tetrahydrofuryl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, piperazinyl, homopiperazinyl, quinuclidinyl, and the like.
As used herein, the term “aryl” includes monocyclic and polycyclic aromatic groups, including aromatic carbocyclic and aromatic heterocyclic groups, each of which may be optionally substituted. As used herein, the term “carbaryl” includes aromatic carbocyclic groups, each of which may be optionally substituted. Illustrative aromatic carbocyclic groups described herein include, but are not limited to, phenyl, naphthyl, and the like. As used herein, the term “heteroaryl” includes aromatic heterocyclic groups, each of which may be optionally substituted. Illustrative aromatic heterocyclic groups include, but are not limited to, pyridinyl, pyrimidinyl, pyrazinyl, triazinyl, tetrazinyl, quinolinyl, quinazolinyl, quinoxalinyl, thienyl, pyrazolyl, imidazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, triazolyl, benzimidazolyl, benzoxazolyl, benzthiazolyl, benzisoxazolyl, benzisothiazolyl, and the like.
As used herein, the term “amino” includes the group NH 2 , alkylamino, and dialkylamino, where the two alkyl groups in dialkylamino may be the same or different, i.e. alkylalkylamino. Illustratively, amino includes methylamino, ethylamino, dimethylamino, methylethylamino, and the like. In addition, it is to be understood that when amino modifies or is modified by another term, such as aminoalkyl, or acylamino, the above variations of the term amino are included therein. Illustratively, aminoalkyl includes H 2 N-alkyl, methylaminoalkyl, ethylaminoalkyl, dimethylaminoalkyl, methylethylaminoalkyl, and the like. Illustratively, acylamino includes acylmethylamino, acylethylamino, and the like.
As used herein, the term “amino and derivatives thereof” includes amino as described herein, and alkylamino, alkenylamino, alkynylamino, heteroalkylamino, heteroalkenylamino, heteroalkynylamino, cycloalkylamino, cycloalkenylamino, cycloheteroalkylamino, cycloheteroalkenylamino, arylamino, arylalkylamino, arylalkenylamino, arylalkynylamino, acylamino, and the like, each of which is optionally substituted. The term “amino derivative” also includes urea, carbamate, and the like.
As used herein, the term “hydroxy and derivatives thereof” includes OH, and alkyloxy, alkenyloxy, alkynyloxy, heteroalkyloxy, heteroalkenyloxy, heteroalkynyloxy, cycloalkyloxy, cycloalkenyloxy, cycloheteroalkyloxy, cycloheteroalkenyloxy, aryloxy, arylalkyloxy, arylalkenyloxy, arylalkynyloxy, acyloxy, and the like, each of which is optionally substituted. The term “hydroxy derivative” also includes carbamate, and the like.
As used herein, the term “thio and derivatives thereof” includes SH, and alkylthio, alkenylthio, alkynylthio, heteroalkylthio, heteroalkenylthio, heteroalkynylthio, cycloalkylthio, cycloalkenylthio, cycloheteroalkylthio, cycloheteroalkenylthio, arylthio, arylalkylthio, arylalkenylthio, arylalkynylthio, acylthio, and the like, each of which is optionally substituted. The term “thio derivative” also includes thiocarbamate, and the like.
As used herein, the term “acyl” includes formyl, and alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, heteroalkylcarbonyl, heteroalkenylcarbonyl, heteroalkynylcarbonyl, cycloalkylcarbonyl, cycloalkenylcarbonyl, cycloheteroalkylcarbonyl, cycloheteroalkenylcarbonyl, arylcarbonyl, arylalkylcarbonyl, arylalkenylcarbonyl, arylalkynylcarbonyl, acylcarbonyl, and the like, each of which is optionally substituted.
As used herein, the term “carboxylate and derivatives thereof” includes the group CO 2 H and salts thereof, and esters and amides thereof, and CN.
The term “optionally substituted” as used herein includes the replacement of hydrogen atoms with other functional groups on the radical that is optionally substituted. Such other functional groups illustratively include, but are not limited to, amino, hydroxyl, halo, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, nitro, sulfonic acids and derivatives thereof, carboxylic acids and derivatives thereof, and the like. Illustratively, any of amino, hydroxyl, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, and/or sulfonic acid is optionally substituted.
As used herein, the term “optionally substituted aryl” includes the replacement of hydrogen atoms with other functional groups on the aryl that is optionally substituted. Such other functional groups illustratively include, but are not limited to, amino, hydroxyl, halo, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, nitro, sulfonic acids and derivatives thereof, carboxylic acids and derivatives thereof, and the like. Illustratively, any of amino, hydroxyl, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, and/or sulfonic acid is optionally substituted.
Illustrative substituents include, but are not limited to, a radical —(CH 2 ) x Z X , where x is an integer from 0-6 and Z X is selected from halogen, hydroxy, alkanoyloxy, including C 1 -C 6 alkanoyloxy, optionally substituted aroyloxy, alkyl, including C 1 -C 6 alkyl, alkoxy, including C 1 -C 6 alkoxy, cycloalkyl, including C 3 -C 8 cycloalkyl, cycloalkoxy, including C 3 -C 8 cycloalkoxy, alkenyl, including C 2 -C 6 alkenyl, alkynyl, including C 2 -C 6 alkynyl, haloalkyl, including C 1 -C 6 haloalkyl, haloalkoxy, including C 1 -C 6 haloalkoxy, halocycloalkyl, including C 3 -C 8 halocycloalkyl, halocycloalkoxy, including C 3 -C 8 halocycloalkoxy, amino, C 1 -C 6 alkylamino, (C 1 -C 6 alkyl)(C 1 -C 6 alkyl)amino, alkylcarbonylamino, N—(C 1 -C 6 alkyl)alkylcarbonylamino, aminoalkyl, C 1 -C 6 alkylaminoalkyl, (C 1 -C 6 alkyl)(C 1 -C 6 alkyl)aminoalkyl, alkylcarbonylaminoalkyl, N—(C 1 -C 6 alkyl)alkylcarbonylaminoalkyl, cyano, and nitro; or Z X is selected from —CO 2 R 4 and —CONR 5 R 6 , where R 4 , R 5 , and R 6 are each independently selected in each occurrence from hydrogen, C 1 -C 6 alkyl, and aryl-C 1 -C 6 alkyl.
The term “prodrug” as used herein generally refers to any compound that when administered to a biological system generates a biologically active compound as a result of one or more spontaneous chemical reaction(s), enzyme-catalyzed chemical reaction(s), and/or metabolic chemical reaction(s), or a combination thereof. In vivo, the prodrug is typically acted upon by an enzyme (such as esterases, amidases, phosphatases, and the like), simple biological chemistry, or other process in vivo to liberate or regenerate the more pharmacologically active drug. This activation may occur through the action of an endogenous host enzyme or a non-endogenous enzyme that is administered to the host preceding, following, or during administration of the prodrug. Additional details of prodrug use are described in U.S. Pat. No. 5,627,165; and Pathalk et al., Enzymic protecting group techniques in organic synthesis, Stereosel. Biocatal. 775-797 (2000). It is appreciated that the prodrug is advantageously converted to the original drug as soon as the goal, such as targeted delivery, safety, stability, and the like is achieved, followed by the subsequent rapid elimination of the released remains of the group forming the prodrug.
Prodrugs may be prepared from the compounds described herein by attaching groups that ultimately cleave in vivo to one or more functional groups present on the compound, such as —OH—, —SH, —CO 2 H, —NR 2 . Illustrative prodrugs include but are not limited to carboxylate esters where the group is alkyl, aryl, aralkyl, acyloxyalkyl, alkoxycarbonyloxyalkyl as well as esters of hydroxyl, thiol and amines where the group attached is an acyl group, an alkoxycarbonyl, aminocarbonyl, phosphate or sulfate. Illustrative esters, also referred to as active esters, include but are not limited to 1-indanyl, N-oxysuccinimide; acyloxyalkyl groups such as acetoxymethyl, pivaloyloxymethyl, β-acetoxyethyl, β-pivaloyloxyethyl, 1-(cyclohexylcarbonyloxy)prop-1-yl, (1-aminoethyl)carbonyloxymethyl, and the like; alkoxycarbonyloxyalkyl groups, such as ethoxycarbonyloxymethyl, α-ethoxycarbonyloxyethyl, β-ethoxycarbonyloxyethyl, and the like; dialkylaminoalkyl groups, including di-lower alkylamino alkyl groups, such as dimethylaminomethyl, dimethylaminoethyl, diethylaminomethyl, diethylaminoethyl, and the like; 2-(alkoxycarbonyl)-2-alkenyl groups such as 2-(isobutoxycarbonyl) pent-2-enyl, 2-(ethoxycarbonyl)but-2-enyl, and the like; and lactone groups such as phthalidyl, dimethoxyphthalidyl, and the like.
Further illustrative prodrugs contain a chemical moiety, such as an amide or phosphorus group functioning to increase solubility and/or stability of the compounds described herein. Further illustrative prodrugs for amino groups include, but are not limited to, (C 3 -C 20 )alkanoyl; halo-(C 3 -C 20 )alkanoyl; (C 3 -C 20 )alkenoyl; (C 4 -C 7 )cycloalkanoyl; (C 3 -C 6 )-cycloalkyl(C 2 -C 16 )alkanoyl; optionally substituted aroyl, such as unsubstituted aroyl or aroyl substituted by 1 to 3 substituents selected from the group consisting of halogen, cyano, trifluoromethanesulphonyloxy, (C 1 -C 3 )alkyl and (C 1 -C 3 )alkoxy, each of which is optionally further substituted with one or more of 1 to 3 halogen atoms; optionally substituted aryl(C 2 -C 16 )alkanoyl, such as the aryl radical being unsubstituted or substituted by 1 to 3 substituents selected from the group consisting of halogen, (C 1 -C 3 )alkyl and (C 1 -C 3 )alkoxy, each of which is optionally further substituted with 1 to 3 halogen atoms; and optionally substituted heteroarylalkanoyl having one to three heteroatoms selected from O, S and N in the heteroaryl moiety and 2 to 10 carbon atoms in the alkanoyl moiety, such as the heteroaryl radical being unsubstituted or substituted by 1 to 3 substituents selected from the group consisting of halogen, cyano, trifluoromethanesulphonyloxy, (C 1 -C 3 )alkyl, and (C 1 -C 3 )alkoxy, each of which is optionally further substituted with 1 to 3 halogen atoms. The groups illustrated are exemplary, not exhaustive, and may be prepared by conventional processes.
It is understood that the prodrugs themselves may not possess significant biological activity, but instead undergo one or more spontaneous chemical reaction(s), enzyme-catalyzed chemical reaction(s), and/or metabolic chemical reaction(s), or a combination thereof after administration in vivo to produce the compound described herein that is biologically active or is a precursor of the biologically active compound. However, it is appreciated that in some cases, the prodrug is biologically active. It is also appreciated that prodrugs may often serves to improve drug efficacy or safety through improved oral bioavailability, pharmacodynamic half-life, and the like. Prodrugs also refer to derivatives of the compounds described herein that include groups that simply mask undesirable drug properties or improve drug delivery. For example, one or more compounds described herein may exhibit an undesirable property that is advantageously blocked or minimized may become pharmacological, pharmaceutical, or pharmacokinetic barriers in clinical drug application, such as low oral drug absorption, lack of site specificity, chemical instability, toxicity, and poor patient acceptance (bad taste, odor, pain at injection site, and the like), and others. It is appreciated herein that a prodrug, or other strategy using reversible derivatives, can be useful in the optimization of the clinical application of a drug.
As used herein, the term “treating”, “contacting” or “reacting” when referring to a chemical reaction means to add or mix two or more reagents under appropriate conditions to produce the indicated and/or the desired product. It should be appreciated that the reaction which produces the indicated and/or the desired product may not necessarily result directly from the combination of two reagents which were initially added, i.e., there may be one or more intermediates which are produced in the mixture which ultimately leads to the formation of the indicated and/or the desired product.
As used herein, the term “composition” generally refers to any product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combinations of the specified ingredients in the specified amounts. It is to be understood that the compositions described herein may be prepared from isolated compounds described herein or from salts, solutions, hydrates, solvates, and other forms of the compounds described herein. It is also to be understood that the compositions may be prepared from various amorphous, non-amorphous, partially crystalline, crystalline, and/or other morphological forms of the compounds described herein. It is also to be understood that the compositions may be prepared from various hydrates and/or solvates of the compounds described herein. Accordingly, such pharmaceutical compositions that recite compounds described herein are to be understood to include each of, or any combination of, the various morphological forms and/or solvate or hydrate forms of the compounds described herein. Illustratively, compositions may include one or more carriers, diluents, and/or excipients. The compounds described herein, or compositions containing them, may be formulated in a therapeutically effective amount in any conventional dosage forms appropriate for the methods described herein. The compounds described herein, or compositions containing them, including such formulations, may be administered by a wide variety of conventional routes for the methods described herein, and in a wide variety of dosage formats, utilizing known procedures (see generally, Remington: The Science and Practice of Pharmacy, (21 st ed., 2005)).
EXAMPLES
Synthesis of Dipeptide 3
4.9 g of dipeptide 1 (11.6 mmol) was dissolved in 60 mL dichloromethane, imidazole (0.87 g, 12.7 mmol) was added to the resulting solution at 0° C. The reaction mixture was warmed slightly to dissolve all solids and re-cooled to 0° C. TESC1 (2.02 mL, 12.1 mmol) was added drop-wise at 0° C., the reaction mixture was stirred under argon and warmed to room temperature over 2 h. TLC (3:1 hexanes/EtOAc) showed complete conversion. The reaction was filtered to remove the imidazole HCl salt, extracted with de-ionized water, and the aqueous phase was back-washed with dichloromethane, the combined organic phase was washed with brine, dried over Na 2 SO 4 , filtered to remove the Na 2 SO 4 , concentrated under reduced pressure, co-evaporated with toluene and dried under high-vacuum overnight to give 6.4 g of crude product 2 (vs 5.9 g of theoretical yield).
The crude product 2 was co-evaporated with toluene again and used without further purification. TES protected dipeptide was dissolved in 38 mL THF (anhydrous, inhibitor-free) and cooled to −45° C. and stirred for 15 minutes before adding KHMDS (0.5 M in toluene, 25.5 mL, 12.8 mmol, 1.1 equiv) drop-wise. After the addition of KHMDS was complete, the reaction mixture was stirred at −45° C. for 15 minutes, and chloromethyl butyrate (1.8 mL, 1.2 equiv, 14 mmol) was added. The reaction mixture changed from light yellow to a blueish color. TLC (20% EtOAc/petroleum ether) showed the majority of starting material was converted. LC-MS showed about 7% starting material left. The reaction was quenched by adding 3 mL MeOH, the mixture was warmed to room temperature and concentrated under reduced pressure to an oily residue. The residue was dissolved in petroleum ether and passed through short silica plug to remove the potassium salt. The plug was washed with 13% EtOAc/petroleum ether, and the collected eluates were combined and concentrated under reduced pressure. The crude alkylated product was passed through an additional silica plug (product/silica=1:50) and eluted with 13% EtOAc/petroleum ether to remove residual starting material to give 5.7 g of product 3 (two steps, yield 76%)
Synthesis of Tripeptide 4
Alkylated dipeptide 3 (4.3 g, 7.0 mmol), N-methyl pipecolinate (MEP) (4.0 g, 28.0 mmol, 4 equiv) and pentafluorophenol (5.7 g, 30.8 mmol. 4.4 equiv) were added to a flask. N-methyl pyrrolidone (NMP, 86 mL) was added to the mixture. To the mixture was added diisopropylcarbodiimide (DIC, 4.77 mL, 30.8 mmol, 4.4 equiv) was added to the mixture. The mixture was stirred at room temperature for 1 h. Pd/C (10%, dry, 1.7 g) was added. The flask was shaken under hydrogen (30-35 psi) for 5 hours. The reaction mixture was analyzed by HPLC. The starting material was found to be less than 3%. The mixture was filtered through diatomaceous earth. The diatomaceous earth was extracted with 200 mL ethyl acetate. The filtrate and the ethyl acetate extract were combined and transferred to a separatory funnel and washed with 1% NaHCO 3 /10% NaCl solution (200 mL×4). The organic layer was isolated and evaporated on a rotary evaporator under reduced pressure. The crude product was dissolved in 40 mL of MeOH/H 2 O (3:1). The crude product solution was loaded onto a Biotage C18 column (Flash 65i, 350 g, 450 mL, 65×200 mm) and eluted with buffer A [10 mM NH 4 OAc/ACN (1:1)] and B (ACN, acetonitrile). The fractions were collected and organic solvent was removed by evaporating on a rotary evaporator. 100 mL of 10% NaCl solution and 100 mL of methyl tert-butyl ether (MTBE) were added to the flask and the mixture was transferred to a separatory funnel. The organic layer was isolated and dried over anhydrous Na 2 SO 4 , filtered and evaporated on a rotary evaporator to dryness. 2.5 g of tripeptide intermediate 4 was obtained (yield 50%).
Synthesis of Tripeptide Acid 6
To 2 L of 0.05 M phosphate (pH=7.4) at 30° C. was added 3.6 g of porcine liver esterase (17 units/mg). 3.0 g of methyl ester 4 was dissolved in 100 mL of DMSO. The first 50 mL of this solution was added at a rate of 1.1 mL/h, and the second half was added at a rate of 1.2 mL/h via syringe pump. After the addition was complete, the reaction mixture was allowed to stir at 30° C. for several hours. HPLC of an EtOAc extract of the reaction mixture showed the reaction was complete. The reaction mixture was drained from the reactor in 1 L portions and extracted with EtOAc (3×1 L). The combined extracts were washed with brine, dried over Mg 2 SO 4 and concentrated under reduced pressure. 2.8 g of product 6 was recovered (95%). The product appeared to be clean by UPLC analysis, except for pentafluorophenol carried over from the previous reaction.
Intermediate 6 spectral data: LCMS (ESI) [M+H] + 697.3; 1 H NMR (CD3OD) 8.02 (s, 1H), 5.94 (d, J=12.3 Hz, 1H), 5.48 (d, J=12.3 Hz, 1H), 4.93 (d, J=8.2 Hz, 1H), 4.65 (d, J=8.5 Hz, 1H), 3.63 (s, br, 1H), 2.91 (br, 1H), 2.67 (s, 3H), 2.53-2.14 (m, 3H), 2.14-1.94 (m, 4H), 1.94-1.74 (m, 4H), 1.74-1.50 (m, 4H), 1.28-1.17 (m, 1H), 1.02-0.83 (m, 24H), 0.71-0.55 (m, 6H).
Synthesis of Tubulysin B
1.4 g (2.01 mmol) of tripeptide 6 was dissolved in 8.4 mL THF and 327.4 μL (2.01 mmol) of 3HF.NEt 3 was added and the reaction mixture stirred for 30 minutes. LC-MS analysis (10% to 100% acetonitrile, pH 7 buffer) confirmed complete deprotection of the TES group. THF was removed under reduced pressure. The residue was dried under high vacuum for 5 minutes. The crude product was dissolved in 8.4 mL dry pyridine. 2.85 mL (30.15 mmol, 15 equiv) of Ac 2 O was added at 0° C. The resulting clear solution was stirred at room temperature for 3.5 hours. LC-MS analysis (10% to 100% acetonitrile, pH 7.0) indicated >98% conversion. 56 mL of dioxane/H 2 O was added and the resulting mixture stirred at room temperature for 1 hour. The mixture was concentrated under reduced pressure. The residue was co-evaporated with toluene (3×) and dried under high vacuum overnight. Crude product 7 was used directly for the next reaction.
Intermediate 7 spectral data: LCMS (ESI) [M+H] + 625.2; 1 H NMR (CD3OD) 8.00 (s, 1H), 6.00 (s, br, 1H), 5.84 (d, J=12.1 Hz, 1H), 5.40 (d, J=12.1 Hz, 1H), 4.63 (d, J=9.1 Hz, 1H), 3.09 (br, 1H), 2.60-2.20 (m, 7H), 2.12 (s, 3H), 2.09-1.86 (m, 3H), 1.80-1.63 (m, 3H), 1.59 (m, 5H), 1.19 (m, 1H), 1.03-0.81 (m, 15H); 13 C NMR (CD3OD) 176.2, 174.2, 172.1, 169.1, 155.5, 125.2, 71.4, 69.6, 56.6, 55.5, 44.3, 37.7, 37.1, 36.4, 32.0, 31.2, 25.6, 23.7, 21.0, 20.9, 20.7, 19.3, 16.5, 14.2, 11.0
Method A. The crude tripeptide acid 7 was dissolved in 28 mL EtOAc (anhydrous) and 740 mg (4.02 mmol, 2.0 equiv) of pentafluorophenol was added, followed by 1.04 g (5.03 mmol, 2.5 equiv) of DCC. The resulting reaction mixture was stirred at room temperature for 1 hour. LC-MS (5% to 80% acetonitrile, pH=2.0, formic acid) analysis indicated >95% conversion. The urea by-product was filtered off, the EtOAc was removed under reduced pressure, and the residue was dried under high vacuum for 5 minutes. The residue was dissolved in 8.4 mL DMF, and tubutyrosine hydrochloride salt (Tut-HCl, 678.7 mg, 2.61 mmol, 1.3 equiv) was added, followed by DIPEA (2.28 mL, 13.07 mmol, 6.5 equiv). The resulting clear solution was stirred at room temperature for 10 minutes. The reaction mixture was diluted with DMSO and purified on prep-HPLC (X-bridge column, 10 mM NH 4 OAc, pH=6.3, 25% to 100% acetonitrile). Pure fractions were combined, acetonitrile was removed under reduced pressure, extracted with EtOAc (3×), and dried over Na 2 SO 4 . The EtOAc was removed under reduced pressure and the residue was dried under high vacuum for 1 hour to yield 513 mg of the desired product (31% combined yield from 6).
Method B. Tripeptide 7 (229 mg, 0.367 mmol) was dissolved in EtOAc (anhydrous), 134.9 mg (0.733 mmol, 2.0 equiv) of pentafluorophenol was added, followed by 970 mg (1.84 mmol, 5.0 equiv) of DCC on the resin. The resulting reaction mixture was stirred at room temperature for 16 hours. LC-MS analysis indicated >96% conversion. The reaction mixture was filtered and concentrated to dryness, dried under high vacuum for 5 minutes. The residue was dissolved in 3.5 mL DMF, Tut-HCl (123.9 mg, 0.477 mmol, 1.3 equiv) was added, followed by DIPEA (0.42 mL, 2.386 mmole, 6.5 equiv). The resulting clear solution was stirred at room temperature for 10 minutes. The reaction mixture was diluted with DMSO, purified on prep-HPLC (X-bridge column, 10 mM NH 4 OAc, 25% to 100%, two runs). The pure fractions were combined, the acetonitrile was removed under reduced pressure, the residue was extracted with EtOAc (2×) and the combined EtOAc extracts dried over Na 2 SO 4 . The EtOAc was removed under reduced pressure. The residue was dried under high vacuum for 1 hour to yield 175 mg of desired product (58% combined yield from 6).
Large Scale Synthesis of Dipeptide 3
10.2 g of dipeptide 1 (25.6 mmol) was dissolved in 130 mL dichloromethane, imidazole (1.9 g, 28.1 mmol) was added to the resulting solution at 0° C. The reaction mixture was warmed slightly to dissolve all solids and re-cooled to 0° C. TESC1 (4.5 mL, 26.8 mmol) was added drop-wise at 0° C., the reaction mixture was stirred under argon and warmed to room temperature over 2 h. TLC (3:1 hexanes/EtOAc) showed complete conversion. The reaction was filtered to remove the imidazole HCl salt, extracted with de-ionized water, and the aqueous phase was back-washed with dichloromethane, the combined organic phase was washed with brine, dried over Na 2 SO 4 , filtered to remove the Na 2 SO 4 , concentrated under reduced pressure, co-evaporated with toluene and dried under high-vacuum overnight to give 12.2 g of product 2.
The crude product 2 was co-evaporated with toluene again and used without further purification. TES protected dipeptide was dissolved in 80 mL THF (anhydrous, inhibitor-free) and cooled to −45° C. and stirred for 15 minutes before adding KHMDS (0.5 M in toluene, 50 mL, 25.0 mmol, 1.05 equiv) drop-wise. After the addition of KHMDS was complete, the reaction mixture was stirred at −45° C. for 15 minutes, and chloromethyl butyrate (3.6 mL, 1.2 equiv, 28.3 mmol) was added. The reaction mixture changed from light yellow to a blueish color. TLC (20% EtOAc/petroleum ether) showed the reaction was complete. The reaction was quenched by adding 20 mL MeOH, the mixture was warmed to room temperature and concentrated under reduced pressure to an oily residue. The residue was dissolved in petroleum ether and passed through short silica plug to remove the potassium salt. The plug was washed with 13% EtOAc/petroleum ether, and the collected eluents were combined and concentrated under reduced pressure to give 12.1 g of product 3 (two steps, yield 76%)
Large Scale Synthesis of Tripeptide 4
Alkylated dipeptide 3 (7.6 g, 12.4 mmol), N-methyl pipecolinate (MEP) (7.0 g, 48.9 mmol, 4 equiv) and pentafluorophenol (10.0 g, 54.3 mmol. 4.4 equiv) were added to a flask. N-methyl pyrrolidone (NMP, 152 mL) was added to the mixture. To the mixture was added diisopropylcarbodiimide (DIC, 8.43 mL, 54.4 mmol, 4.4 equiv) was added to the mixture. The mixture was stirred at room temperature for 1 h. Pd/C (10%, dry, 3.0 g) was added. The flask was shaken under hydrogen (30-35 psi) for 5 hours. The reaction mixture was analyzed by HPLC. The reaction was complete. The mixture was filtered through celite. The celite was washed with 500 mL ethyl acetate. The solutions were combined and transferred to a separatory funnel and washed with 1% NaHCO 3 /10% NaCl solution (250 mL×4). The organic layer was isolated and evaporated on a rotary evaporator under reduced pressure. The crude product was dissolved in dichloromethane and the urea was filtered. The crude product solution was loaded onto a Teledyne Redisep Silica Column (330 g) and purified with EtOAc/petroleum ether on CombiFlash flash chromatography system. The fractions were collected and organic solvent was removed by evaporating to give 5.0 g of the tripeptide (61%). NMR and mass spectral data were consistent with those measured for the Example
Large Scale Synthesis of Tripeptide Acid 6
To 2 L of 0.05 M phosphate (pH=7.4) at 30° C. was added 3.6 g of porcine liver esterase (17 units/mg). 3.0 g of methyl ester 4 was dissolved in 100 mL of DMSO. The first 50 mL of this solution was added at a rate of 1.1 mL/h, and the second half was added at a rate of 1.2 mL/h via syringe pump. After the addition was complete, the reaction mixture was allowed to stir at 30° C. for several hours. HPLC of an EtOAc extract of the reaction mixture showed the reaction was complete. The reaction mixture was drained from the reactor in 1 L portions and extracted with 94% EtOAc-6% MeOH (vol./vol.) solution (3×1 L). The combined extracts were washed with brine, dried over Na 2 SO 4 and concentrated under reduced pressure. 2.8 g of product 6 was recovered (95%). The product appeared to be clean by UPLC analysis, except for pentafluorophenol carried over from the previous reaction.
Large Scale Synthesis of Tubulysin B
3.0 g (4.30 mmol) of tripeptide 6 was dissolved in 18 mL THF and 0.70 mL (4.30 mmol) of 3HF.NEt 3 was added and the reaction mixture stirred for 30 minutes. LC-MS analysis (10% to 100% acetonitrile, pH 7 buffer) confirmed complete deprotection of the TES group. THF was removed under reduced pressure. The residue was dried under high vacuum for 5 minutes. The crude product was dissolved in 18 mL dry pyridine. 6.11 mL (64.50 mmol, 15 equiv) of Ac 2 O was added at 0° C. The resulting clear solution was stirred at room temperature for 5 hours. LC-MS analysis (10% to 100% acetonitrile, pH 7.0) indicated >98% conversion. 117 mL of dioxane/H 2 O was added and the resulting mixture stirred at room temperature for 1 hour. The mixture was concentrated under reduced pressure. The residue was co-evaporated with toluene (3×) and dried under high vacuum overnight. Crude product 7 was used directly for the next reaction. LCMS (ESI) [M+H] + 625.2; the NMR spectral data was consistent with structure 7.
Method B. The crude tripeptide acid 7 (2.67 g, 4.30 mmol) was dissolved in 43 mL of DCM (anhydrous), 1.59 g (8.6 mmol, 2.0 equiv) of pentafluorophenol was added, followed by 9.33 g (21.5 mmol, 5.0 equiv) of DCC on the resin. The resulting reaction mixture was stirred at room temperature for 16 hours. LC-MS analysis indicated >96% conversion. The reaction mixture was filtered and concentrated to dryness, dried under high vacuum for 5 minutes. The residue was dissolved in 16.5 mL DMF, Tut-HCl (1.45 g, 5.59 mmol, 1.3 equiv) was added, followed by DIPEA (4.88 mL, 27.95 mmol, 6.5 equiv). The resulting clear solution was stirred at room temperature for 10 minutes. The reaction mixture was purified on prep-HPLC (X-bridge column, 50 mM NH 4 HCO 3 , 25% to 100%, six runs). The pure fractions were combined, the acetonitrile was removed under reduced pressure, the residue was extracted with EtOAc (2×) and the combined EtOAc extracts dried over Na 2 SO 4 . The EtOAc was removed under reduced pressure. The residue was dried under high vacuum for 1 hour to yield 1.35 g of desired product (38% combined yield from 4). NMR spectral data was consistent with the tubulysin B. | Tubulysins are a series of naturally occurring cytotoxic agents that are of interest as anticancer therapeutic agents. Processes and intermediates useful for preparing naturally occurring and non-naturally occurring tubulysins and analogs and derivatives thereof are described. | 2 |
BACKGROUND OF THE INVENTION
The invention is broadly concerned with disposable fast food containers, and particularly such containers formed from foldable blanks or sheets of shape-sustaining paperboard, thin cardboard, and the like.
The individual containers are normally adapted for particular foodstuffs. For example, a container for hamburgers is conventionally an approximately square upwardly opening tray which, in a "clam shell" version, includes an integrally formed closable lid or cover. The typical french fry container, for french fried potatoes, onion rings, and the like, is vertically elongate tapering from a narrow lower or base end to a wide upwardly directed mouth which facilitates both the introduction of the fries and the individual removal of the fries. Such fry containers are normally incapable of standing upright in a stable manner, and more frequently lie flat on the table or serving tray with the fries spilling therefrom.
One of the most commonly ordered fast food meals is "burger and fries". Such a combination is in fact usually encouraged by the offering of a special price slightly less than that were the items ordered separately. Heretofore, such an order has required the use of two separate containers, respectively specifically formed to accommodate the hamburger and the fries. This is turn requires the separate handling of two containers, both by the server and by the customer. The separate tall tapered fry container also requires special handling to accommodate the tendency of such containers to not stand upright in most circumstances.
The necessary use of two containers also requires that, during manufacture, separate equipment be provided to form the distinctly different containers or cartons from different basic blanks.
Other factors which enter into the consideration of the nature of disposable fast food containers include the amount of materials used and the problems in disposing of the used cartons in an environmentally correct manner. All of these factors must be considered in arriving at both a practical and user friendly carton, in conjunction with a carton which is economically feasible, that is adding minimal costs to the meal contained therein. As will be appreciated, any reduction in the cost of the carton itself can produce substantial savings when considering the thousands of meals served in such cartons at any typical fast food establishment.
SUMMARY OF THE INVENTION
The food carton or container of the present invention is of a construction which provides significant economic, user friendly and environmental advantages from the initial manufacture thereof through the final disposal.
More particularly, the carton is specifically configured to accommodate the typical combination fast food meal of a "burger and fries" in a single stable carton wherein the foodstuffs are received in separate although communicating compartments.
The carton is formed from a single compact blank, thus substantially reducing board usage as compared to the prior necessity of forming two separate cartons. This advantage is carried through all stages of the manufacturing process, including the die cutting of the board, and the remaining manufacturing steps including the folding, gluing and stacking of the containers.
Subsequently, the server need only handle a single carton in providing the "meal" of burgers and fries. The loaded carton can in turn be placed on the customer's tray without fear of spillage in that the fry compartment is stabilized and maintained upright through its integral association with the burger compartment.
The customer or consumer is also provided with a single easily carried carton wherein the individual foodstuffs are substantially segregated and the tendency for the fries to spill from a tipped container is eliminated. Rather, at the time of consumption, the fries will merely gradually flow into the burger compartment as the burger is removed. In this manner, the fries remain confined on the clean inner food surface of the carton, rather than spilling on the tray or tabletop.
Subsequent disposal of the single carton, as opposed to two cartons as heretofore required by a meal of burgers and fries inherently simplifies disposal considerations.
In achieving the advantages of the invention, the carton is formed with a tray portion having two separate although communicating compartments with a common elongate base or bottom panel. One compartment comprises a major portion of the length of the carton, and includes low outer end and side walls defining a tray-like receptacle with a lid or cover integrally hinged to the end wall and selectively foldable to overlie the side walls and base, generally in the manner of a clam-shell burger container.
The fry compartment, formed at the opposite end of the elongate base, includes an outer end wall and side walls all of a greater height than the first compartment walls, and forming a configuration generally similar to that of a partial conventional fry container opening upward above the closed lid of the burger compartment.
The fry compartment has no separate inner wall opposed from the outer wall. Rather, the inner face of the fry compartment is defined by the depending forward or inner wall on the lid which tapers generally in the manner of the fry compartment outer wall and tends to separately maintain the fries against free movement into the burger compartment until such time as the lid is raised and the burger removed.
The carton itself is easily carried by one hand, both when loading the foodstuffs and by the customer. In addition, the construction is such whereby the burger compartment lid, in addition to covering the burger compartment and defining the general parameters of the fry compartment, also, with or without positive interlock engages and stabilize the tall relatively narrow walls of the fry compartment. It is also contemplated that lift-assisting means be integrally formed with the lid to facilitate an opening of the lid.
Other features, objects and advantages of the invention will become apparent from the more detailed description following hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of the dual compartment carton of the invention;
FIG. 2 is a perspective view with the lid opened generally 90 degrees to the burger compartment;
FIG. 3 is a perspective view with the lid moved toward the closed position;
FIG. 4 is a transverse cross-sectional view taken substantially on a plane passing along line 4--4 in FIG. 1.
FIG. 5 is a top perspective view of a second embodiment incorporating locking lugs releasably fixing the position of the closed lid, and lifting tabs;
FIG. 6 is a perspective view of the carton of FIG. 5 with the lid open;
FIG. 7 is a perspective detail of the locking engagement of the lid;
FIG. 8 is a top perspective view of a further embodiment incorporating locking lugs and lift means;
FIG. 9 is a perspective view of the carton of FIG. 8 with the lid open;
FIG. 10 is a longitudinal cross-sectional view taken substantially on a plane passing along line 10--10 in FIG. 8;
FIG. 11 is a plan view of the blank from which the carton of FIG. 1 is formed;
FIG. 12 is a plan view of the blank from which the carton of FIG. 5 is formed; and
FIG. 13 is a plan view of the blank from which the carton of FIG. 8 is formed.
DESCRIPTION OF PREFERRED EMBODIMENTS
Turning first to FIGS. 1-4 and 11, the carton 20 is folded from a unitary blank 22 of appropriate paperboard material and retained in the carton configuration by adhesive bonding.
The carton 20 is of an elongate rectangular configuration with a base on bottom panel 24. A first outer end wall 26 is integral with one end of the base 24 along a fold line 28 and is coextensive with the corresponding end of the base.
A pair of side walls 30 are integral with the opposed side edges of the base 24 along the full length thereof with a fold line 32 defined between each side wall 30 and the adjacent base side edge.
Each of the side walls 30, for a major portion of the length thereof inward from the outer wall 26, is of substantial equal height with the outer wall 26. A minor portion of the length of each side wall 30, adjacent the remote end of each side wall 30, extends to a greater height than the end wall 26 to an upper edge which defines a support ledge or shoulder 34.
The walls 26 and 30 incline slightly outward upward from the base 24, with the outer wall 26 joined to the corresponding end portions of the side walls 30 by glue flaps 36 integrally folded from the opposed ends of the outer wall 26 and adhesively bonded to the inner faces of the side walls 30. As will be appreciated from FIG. 2, each glue flap 36 includes an upwardly extending portion or projection 38 which extends above the upper edge of the corresponding side wall 30.
The carton 20, remote from the outer end wall 26, includes a second outer end wall 40 coextensive with and folded from the opposite end of the base 24 along fold line 42. The end wall 40 is of a substantially greater height than the side walls 30 and extends above the adjacent shoulder-defining upper edges on the upwardly extending portions of the side walls 30. A pair of vertically elongate side walls 44 are integrally joined, along vertical fold lines 46, along the full height of the opposed vertical edges of the outer end wall 40 and extend inwardly along the opposed sides of the base 24 into overlapping relation to the adjoining end portions of the lower side walls 30. The side walls 44 are bonded to the side walls 30 and are of a width whereby the shoulders 34 on the side walls 30 extend inwardly relative to the slightly tapered inner edges of the side walls 44 at an elevation slightly greater than one half the height of the higher side walls 44. The relatively higher outer end wall 40 is slightly outwardly bowed along the height thereof and includes an arcuate upper edge. The adjacent higher side walls 44 generally follow the slight outward inclination of the lower side walls 30 to which they are adhesively bonded, thereby mutually rigidifying and stabilizing each other and retaining the end wall 40 in an upward, slightly outwardly inclined and slightly bowed position. The upper edges of the side walls 44 taper slightly downward and inward from the opposite ends of the arcuate upper edge of the end wall 40.
The tray portion of the carton thus far defined forms two compartments which, for purposes of identification, will be referred to as a "burger compartment" 48 and a "fry compartment" 50. The burger compartment is basically designed by the low end and side walls 26 and 30, while the fry compartment 50 is basically defined by the high end wall 40 and side walls 44. As will be appreciated from the drawings, each compartment of the unitary carton 20 broadly resembles the configuration of known separate burger and fry cartons.
The carton 20 is completed by the provision of an integral lid or cover 52 for the burger compartment 48. The lid 52 includes a substantially planar top panel 54 with opposed back and front walls 56 and 58, and opposed side walls 60 of equal length with and extending from the corresponding edges of the top panel 54. The walls 56-60 are integral with the top panel 54 with appropriate fold lines defined therebetween.
The lid back wall 56 is of generally equal depth or height as the tray outer wall 26, and coextensive with the upper edge thereof with an integral hinge line 62 therebetween.
The lid side walls 60 are of a slightly greater depth or height than the back wall 56 and flare slightly outward from the top panel 54 to, upon a closing of the lid 52 over the burger compartment 48, lie immediately outward of the lower tray side walls 30. The closing movement of the lid 52 is guided to a degree by the upwardly extending projections 38 on the glue flaps 36 securing the outer wall 26 to the tray side walls 30. As will be best seen in FIG. 2, appropriate glue flaps 64 and 66 are provided on the opposed ends of the lid back wall 56 and lid front wall 58 for adhesive bonding to the inner faces of the corresponding end portions of the opposed lid side walls 60.
The lid front wall 58 is of a forwardly directly concave configuration along the length thereof resulting from the concave nature of the fold line 68 joining the upper edge of the front wall 58 to the forward edge of the top panel 54. The front wall 58 also inclines forwardly as it extends outward from the top panel 54 providing in effect a cross-section configuration generally corresponding to that of the outer end wall 40 of the fry compartment 50, and a generally upwardly widening funnel-configuration to the fry compartment upon a full closing of the lid 52. Introduction of fries into the fry compartment 50 is facilitated by arcuately relieving the lower edge 70 of the lid front wall 58, the significance of this feature possibly being best appreciated from the cross-sectional view of FIG. 10.
The opposed ends of the lid front wall 58, to approximately mid-height, define downwardly directed notches 22 between the front wall edges and the adjoining outwardly flaring forward portions of the lid side walls 60. The upper portions of each of these front wall end edges are joined to the adjacent side walls 60 by the previously described glue flaps 66. The forward end portion of each of the lid side walls 60, in turn, terminates in a forwardly directed extension 74 projecting forward of the front wall 58 and including, aligned with the upper end of the adjacent notch 72, an upwardly directed V-shaped seat 76.
Noting FIGS. 3 and 4, upon a closing of the lid 52, the lid side walls 60 are received immediately outward of the tray side walls 30. The relatively higher forward portions of the side walls 30 are received within the recesses 72 at the opposite ends of the lid front wall 58 with the inner ends of the notches 72 seating on the abutment shoulders 34 immediately inward of the inner edges of the taller side walls 54 defining the fry compartment. The lid 52 is thus in a stabilized position and supported both adjacent the opposed corners of the front wall 58 thereof and along the rear wall 56.
With the lid closed, two distinct although integral and adjacent compartments are formed, one for a hamburger or like sandwich, and the other for an appropriate side order of french fried potatoes, onion rings, or the like. In actual use, the lid will be fully or almost fully open to allow for a placing of the burger within the burger compartment 48. The lid will then be closed to form the distinct fry compartment 50 within which the fries will be introduced. The inclined and arcuate configuration of the lid front wall 58 will tend to restrict the fries to the fry compartment, as will the presence of the burger within the burger compartment. When the meal is to be consumed, the lid can be fully opened and the burger removed, the fries naturally tending to gravitate into the burger compartment to allow for simplified access thereto. Further, inasmuch as the back wall 56 of the lid is of substantially equal height with the tray end wall 26 to which it is hingedly joined, the lid, when fully open, will actually define a separate upwardly opening compartment which can receive the partially eaten burger should it be desired to maintain a complete separation between the burger and fries. The two compartment carton, through the single enlarged base 24, is a stable unit from which the meal can be directly consumed without any danger of tipping or spillage, as for example with the conventional tapered fry carton.
The engagement of the lid side wall extensions 74 with the outer faces of the fry compartment side walls 44, in conjunction with the engagement of the shoulders 34 within the lid notches 72, provide for an effective frictional retention of the lid 52 in its closed position.
However, and noting FIGS. 5-7 wherein like numerals apply to like parts, a more positive lock for the lid 52 is also contemplated. More specifically, the forward edge of each of the fry compartment side walls 44, immediately above the corresponding shoulder 34, is provided with a rearwardly or inwardly directed integral rounded locking lug 78. These lugs 78, noting in particular the detail in FIG. 7 and due to the inherent resilient flexibility of the material of the carton, slide past the lid side wall extensions 74 and, upon a full seating of the lid 52, snap into releasable locking engagement within the upwardly directed locking seats 76 defined by the extensions 74. Release of the locking engagement, and hence the lid 52, will require a positive manual upward pivoting of the forward portion of the lid. In order to facilitate a grasping and opening movement of the lid, in the embodiment of FIGS. 5-7 the top panel 54 includes, along the opposite side edges thereof in close adjacent relation to the front edge, a pair of laterally extending opposed lifting tabs 80, each of which comprises a rigid coplanar extension of the top panel 54. As will be appreciated from the corresponding blank of FIG. 12, the side edge fold line does not extend across the corresponding tab 80. Rather, the tab 80 is, through an appropriate severance line 81, retained coplanar with the top panel 54 as the lid side wall 60 is folded relative thereto.
The width of the lid 52 is easily spanned by the hand of a consumer. As such, the thumb and fingers of a single hand can engage beneath the opposed tabs 80 for a simultaneous upward pull on the opposed sides of the lid for an opening of the hamburger compartment.
It will also be noted that the base or bottom panel 24 of the embodiment of FIGS. 5-7 is slightly upwardly concave along the length of the carton. This configuration, which aids in the stabilization of the carton and provides an insulating air space, is achieved by an arcuate forming of the end fold lines 28, 42 at the integral joinder of the end walls 26 and 40 to the base 24. The arcuate configuration of these fold lines 28 and 42 will be noted in the corresponding blank of FIG. 12.
FIGS. 8-10, along with the blank of FIG. 13 and wherein like numerals refer to like parts, illustrate a further embodiment incorporating the locking lugs 78 and the arcing base or bottom panel. This embodiment differs from the previous embodiment in providing a lifting flap 82 in the top panel 54 in closely spaced adjacent relation to the front wall 58 and generally on the longitudinal center line of the panel. This flap 82 is severed from the panel along three edges thereof and integral with the panel along its forward edge. The flap 82 can extend upwardly from the top panel 54 for easy grasping between the fingers to raise the lid. Alternatively, and as illustrated, the flap can be folded inward relative to the top panel, providing in effect a finger hole to grasp and raise the lid. With either arrangement, the hole defined by the flap 82 will provide a desirable venting of the burger compartment to avoid an overly moist or soggy product.
Additional venting will be provided by the outwardly flaring lid side walls 60 which are spaced outwardly from the upper edges of the tray side walls 30 for a major portion of the length of the burger compartment as the forward portion of the lid is supported on the support shoulders 34. The relative relationship between the upper and lower side walls will be best appreciated from the cross-sectional details of FIGS. 4 and 10.
It is to be appreciated that the tapered walls of the tray and lid of the carton, in addition to being desirable for facilitating the insertion and removal of the foods, particularly in the fry compartment, and for facilitating of the opening and closing of the lid, also perform a significant function in allowing for a stacking of the open cartons prior to use. This simplifies both shipping and storage. It will also be recognized that there is a substantial savings in paperboard material and construction steps as compared to the prior necessity of using two cartons. For example, one wall of the fry container is no longer required in that the adjacent lid wall of the burger compartment fulfills this function. It will also be appreciated that the gluing and folding procedures are substantially no more complex than that required for a single burger container, notwithstanding the dual compartment nature of the carton of the invention. Similarly, the number of glue points and the actual folding steps involved are approximately only what would be required for a burger carton. | A folded paperboard carton including first and second longitudinally aligned compartments with a common base panel, the first compartment including a cover integral therewith and foldable to overlie the first compartment, the second compartment extends above and opens upwardly relative to the closed first compartment with the inner wall of the cover dividing the two compartments. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to shared resource allocation and more particularly to reconfiguring virtual machines for optimized resource allocation and minimized energy waste.
2. Background Description
For any modern organization acquiring and managing Information Technology (IT) is a major budgetary concern. Moreover, the local IT hardware is seldom used at full capacity. So to reduce IT infrastructure costs and waste, instead of acquiring physical hardware, organizations increasingly are sharing resources by replacing some local computers with virtual machines (VMs). Each VM provides a local virtual desktop and runs on a remote physical server. Each desktop has allocated capacity (e.g. disk space, processing resources and memory) and is configured (software stack and licenses) for its intended purpose and expected needs. A key problem to managing these VM desktops is determining optimal capacity and configuration to allocate to each VM.
A typical state of the art service provider allocates/places physical resources for each VM based primarily on provider system optimization, on workload predictions and on results from continuously monitoring VM resource usage. Over-allocation, wastes resources and energy and reduces the capacity available to other users. Under-allocation impairs the users Quality-of-Service (QoS). Preferably, adequate IT resources are allocated without waste, and while also maintaining the desktop user's QoS.
System designers have investigated user/usage profiling and feedback in an effort to further optimize and improve service provider efficiency. User/usage profiles have been generated and used, for example, to deliver targeted content such as user targeted advertisements. Those user profiles have been categorized, for example, through analysis of web usage or mobile browser activity to infer demographic data. User feedback can include reporting software failures and performance degradation; expressing satisfaction with, and improve the quality of provided web content and advertisements; and involve them in the process of classifying emails for spam prevention.
Users can assist administrators in better defining initial desktop configurations and optimizing initial VM placement. For example, a resource management system may provide users with options that change system demands, e.g., to optimize energy consumption and systems energy efficiency. Once placed, however, the provider does not consider user feedback, even for subsequent attempts to consolidate system workload or optimize system resource allocation.
Thus, there is a need for allowing users to provide feedback with respect to a current desktop configuration and capacity, and for allowing users to indicate willingness to update the current desktop configuration for more efficient use of resource, by reducing the desktop capacity; and more particularly, there is a need for reconfiguring virtual desktops in response to such feedback, for example, consolidating the desktops onto fewer servers, thereby reducing IT costs, and further, understanding whether the current desktop configuration is appropriate for each user according to different respective usage profiles.
SUMMARY OF THE INVENTION
A feature of the invention is reduced shared resource energy consumption;
Another feature of the invention is optimized allocation of shared resources in a cloud environment;
Yet another feature of the invention is that cloud environment users are allowed to adjust allocated resources on the fly, whenever the user's client device identifies resource excess that has been allocated for a particular user and/or when the user is unsatisfied with a current resource allocation.
The present invention relates to a shared resource system, method of optimizing resource allocation in real time and computer program products therefor. At least one client device includes an optimization agent monitoring resource usage and selectively suggesting changes to resource configuration for the client device. A management system, e.g., in a cloud environment selectively makes resource capacity available to client devices and adjusts resource capacity available to client devices in response to the optimization agent. Client devices and provider computers connect over a network. The client devices and provider computer pass messages to each other over the network.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
FIG. 1 depicts a cloud computing node according to an embodiment of the present invention;
FIG. 2 depicts a cloud computing environment according to an embodiment of the present invention;
FIG. 3 depicts abstraction model layers according to an embodiment of the present invention;
FIG. 4 shows an example of the target computing environment 70 for application to a preferred embodiment of the present invention;
FIG. 5 shows an example of a group profile table of user profiles maintained by the management system for the entire group of an organization of server users;
FIGS. 6A-B show an example of client devices configured initially using the latest profile table defined by the management system;
FIG. 7 shows an example of how the management system optimizes VM desktop placement on the physical servers, implemented using existing dynamic resource placement and suitable data mining solutions;
FIG. 8A shows a user interface or Graphical User Interface (GUI) on device desktop example during reconfiguration;
FIG. 8B shows an example of the user using the desktop on device to requesting another profile.
DESCRIPTION OF PREFERRED EMBODIMENTS
It is understood in advance that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed and as further indicated hereinbelow.
Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g. networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models.
Characteristics are as follows:
On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service's provider.
Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
Resource pooling: the provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter).
Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.
Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service. Moreover, the present invention provides for client self-monitoring for adjusting individual resource allocation and configuration on-the-fly for optimized resource allocation in real time and with operating costs and energy use minimized.
Service Models are as follows:
Software as a Service (SaaS): the capability provided to the consumer is to use the provider's applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based e-mail). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
Platform as a Service (PaaS): the capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including networks, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.
Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources, sometimes referred to as a hypervisor, where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).
Deployment Models are as follows:
Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises.
Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises.
Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds).
A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure comprising a network of interconnected nodes.
Referring now to FIG. 1 , a schematic of an example of a cloud computing node is shown. Cloud computing node 10 is only one example of a suitable cloud computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, cloud computing node 10 is capable of being implemented and/or performing any of the functionality set forth hereinabove.
In cloud computing node 10 there is a computer system/server 12 , which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.
Computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
As shown in FIG. 1 , computer system/server 12 in cloud computing node 10 is shown in the form of a general-purpose computing device. The components of computer system/server 12 may include, but are not limited to, one or more processors or processing units 16 , a system memory 28 , and a bus 18 that couples various system components including system memory 28 to processor 16 .
Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus.
Computer system/server 12 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 12 , and it includes both volatile and non-volatile media, removable and non-removable media.
System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32 . Computer system/server 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 34 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.
Program/utility 40 , having a set (at least one) of program modules 42 , may be stored in memory 28 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 42 generally carry out the functions and/or methodologies of embodiments of the invention as described herein.
Computer system/server 12 may also communicate with one or more external devices 14 such as a keyboard, a pointing device, a display 24 , etc.; one or more devices that enable a user to interact with computer system/server 12 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 12 to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces 22 . Still yet, computer system/server 12 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 20 . As depicted, network adapter 20 communicates with the other components of computer system/server 12 via bus 18 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 12 . Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
Referring now to FIG. 2 , illustrative cloud computing environment 50 is depicted. As shown, cloud computing environment 50 comprises one or more cloud computing nodes 10 with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone 54 A, desktop computer 54 B, laptop computer 54 C, and/or automobile computer system 54 N may communicate. Nodes 10 may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment 50 to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices 54 A-N shown in FIG. 2 are intended to be illustrative only and that computing nodes 10 and cloud computing environment 50 can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser).
Referring now to FIG. 3 , a set of functional abstraction layers provided by cloud computing environment 50 ( FIG. 2 ) is shown. It should be understood in advance that the components, layers, and functions shown in FIG. 3 are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided:
Hardware and software layer 60 includes hardware and software components. Examples of hardware components include mainframes, in one example IBM® zSeries® systems; RISC (Reduced Instruction Set Computer) architecture based servers, in one example IBM pSeries® systems; IBM xSeries® systems; IBM BladeCenter® systems; storage devices; networks and networking components.
Examples of software components include network application server software, in one example IBM WebSphere® application server software; and database software, in one example IBM DB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter, WebSphere, and DB2 are trademarks of International Business Machines Corporation registered in many jurisdictions worldwide).
Virtualization layer 62 provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers; virtual storage; virtual networks, including virtual private networks; virtual applications and operating systems; and virtual clients.
In one example, management layer 64 may provide the functions described below. Resource provisioning provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may comprise application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. User portal provides access to the cloud computing environment for consumers and system administrators. Service level management provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment provide pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA.
Workloads layer 66 provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation; software development and lifecycle management; virtual classroom education delivery; data analytics processing; transaction processing; and Mobile Desktop.
FIG. 4 shows an example of the target computing environment 70 for application to a preferred embodiment of the present invention with reference to the cloud environment of FIGS. 1-3 with like features labeled identically. In the preferred computing environment 70 users at devices 54 A, 54 B interface through network messages with virtual machines 68 on networked servers 10 A- 10 N. Each virtual machine 68 includes an optimization agent 72 providing environment feedback for adjusting the virtual environment 74 , 76 , 78 for each virtual machine 68 to improve overall system 70 efficiency. Each virtual machine 68 includes an optimization agent 72 collecting resource usage information on virtualized hardware 74 , operating system(s) 76 and applications 78 , which the optimization agent 72 passes to the respective server, 10 A in this example. One software component 78 is a user interface for showing the user possible desktop reconfiguration options. The management system 64 in middleware cooperates with servers 10 A- 10 N allocating resources, modifying allocations in response to reconfigurations, and informing each VM of improved desktop reconfigurations.
Thus, the present invention allows users at networked devices 54 A, 54 B to receive and accept virtual desktop reconfiguration, and provide feedback during use for determining a more optimized resource placement. Each User may be informed of possible virtual desktop reconfigurations on-the-fly according to feedback and respective usage profiles. Accepting a reconfiguration optimizes desktop placement and VM configuration in real time to reduce over-allocated and/or underused/unused resources. Minimizing configuration inefficiency allows data center hardware consolidation and processing capacity reduction for reduced energy use; or, increasing the number of users supported by each server. Thus, the present invention reduces the per user average power consumption in a particular data center, thereby reducing Information Technology (IT) administration costs. Moreover, administrators can better understand resource usage profiles for improved capacity planning quality.
FIG. 5 shows an example of a user profile table 80 that the management system 64 maintains for the entire group of an organization of server users. In this example, the user profile table 80 includes a menu of profiles 82 and a list of users 84 indicating profile assignment. The profile menu 82 includes a set of selectable VM profiles 82 A- 82 M, that may be created initially by a system administrator, for example, and augmented or modified with use as described in more detail hereinbelow. Profiles in the profile menu 82 may also be updated using any suitable data mining technique, such as taught by Geng et al. “Interestingness measures for data mining: A survey” ACM Computing Surveys 2006. The user list 84 includes an entry for each VM and the profile assigned to the respective VM, either the initially assigned profile or the profile assigned as a result of subsequent reconfiguration. It should be noted that although the profile menu 82 and the user list 84 are shown and treated as a unified table 80 , this is for simplicity of description only. It is understood that these two units may be, for example, separately and independently maintained.
In this example, each selectable VM profile 82 A- 82 M, which may be assigned to one or more VMs for requesting users, contains hardware 86 , software 88 and Quality-of-Service (QoS) 90 information. Typical hardware information 86 may indicate CPU, memory, disk, network, among other hardware requirements. Typical software information 88 may include a software systems stack and respective licenses. Typical QoS information 90 may include time to boot the desktop, or time to resume the desktop from standby mode. Each optimization agent 72 also maintains a local copy of the user profile table 80 .
As shown in FIGS. 6A and 6B and with reference to FIGS. 4 and 5 , first the management system 64 configures 100 a VM 68 for each device 54 A, 54 B, 54 C, . . . , 54 N requesting resources. In particular, the management system 64 assigns a profile 82 A- 82 M from profile menu 82 to the respective device 54 A, 54 B, 54 C, . . . , 54 N in the user list 84 . Once the device 54 A, 54 B, 54 C, . . . , 54 N is configured each respective optimization agent 72 manages two processes, a reconfiguration process 110 and a monitoring process 120 , reflected in the data flow of FIG. 6A . In the reconfiguration process 110 , the optimization agent 72 waits 112 for updates to the profile table 80 from the management system 64 . If the management system 64 has provided an update 114 , the optimization agent 72 applies the update 116 .
In the monitoring process 120 the optimization agent 72 monitors 122 user activity and VM 68 behavior. The optimization agent 72 analyzes 124 data from monitoring to determine whether a reconfiguration suggestion 126 should be passed 128 to the user interface. Alternately, the user can suggest reconfiguring the desktop profile, e.g., if the user is dissatisfied with the current configuration. After making the suggestion 128 , or if no suggestion is made, the optimization agent checks the data to determine 130 whether to store 132 the behavior data in the server 10 A. Either after sending the behavior data 132 or if storing the behavior data is unnecessary, the optimization agent 72 returns to continue monitor 122 user activity and VM behavior.
FIG. 7 shows an example of how the management system 64 optimizes 140 VM desktop placement on the physical servers 10 A- 10 N, implemented using existing dynamic resource placement, for example. An example of dynamic resource placement is provided by Ferreto et al. “Server consolidation with migration control for virtualized data centers” Future Generation Computer Systems, 2011.
VM optimization 140 begins when either, the user changes 142 the profile in response to a suggestion from the optimization agent 72 as shown in FIG. 8A or, the user initiates 144 a profile change as shown in FIG. 8B . The management system 64 assigns a different profile in user list 84 to recon figure 146 the respective VM, preferably immediately, or after a preselected interval. Then, the management system 64 passes a notification 148 of the user list 84 changes to the user's device 54 A, 54 B and optimizes data center resources 150 , consolidating where possible. Finally, the management system 64 assesses the impact 152 of the user list 84 changes on resource allocation, e.g., determining power savings and/or added resource availability. The management system 64 can also adjust the profile menu 82 as needed based on VM usage and desktop behavior.
FIG. 8A shows an example of a user interface or Graphical User Interface (GUI) on desktop 160 of client device 54 during reconfiguration in steps 126 and 128 of FIG. 6A . A token 162 displayed on the desktop 160 indicates the current desktop configuration “A,” e.g., textually in the task bar 164 in this example, or iconically. After analyzing user activity and VM behavior 124 with the current desktop “A” 160 , a preferred optimization agent optimizes the configuration, tentatively reconfiguring to a more efficient, optimized desktop “B.” The optimization agent changes the task bar token 162 from “A” to “A->B” and suggests a profile change 126 to optimized desktop “B,” e.g., in a pop-up window 166 .
In this example, pop-up window 166 offers the user the option of exploring the advantages of migrating to optimized desktop “B.” The user can select more detailed information, e.g., with a mouse click or using a voice command. If more detailed information is selected, the optimization agent presents the user with an explanation of why the reconfiguration was suggested and possible impact of reconfiguring. If the user accepts the reconfiguration suggestion 128 , e.g., clicking on the task bar token 162 , the optimization agent provides feedback 142 to management system. The management system changes the profile designation for device 54 from “A” to “B” in the user list 84 .
FIG. 8B shows an example of the user requesting another profile using the desktop 160 GUI on device 54 in FIG. 8A with like features labeled identically and with further reference to FIG. 7 . In this example, the user has become dissatisfied with the current configuration “A,” and clicks 144 on another desktop token 170 . In this example, the current profile tagged with a minus sign, “−A” to indicate a requested change. The desktop 160 responds through the GUI, e.g., providing a pop-up window 172 that offers an opportunity to view alternate profiles. If the user responds in the positive, the desktop 160 may provide a list of profiles 82 A- 82 M in the menu 82 through the GUI, that the user can select. The desktop 160 may also indicate the impact of using each, e.g., the cost and energy consumption associated with each menu profile 82 A- 82 M. When the user selects a different configuration, the optimization agent returns 144 the selection to the management system. The management system uses the profile selection to reallocate resources and, optionally, refine the profile menu 82 to better meet future user resource needs and demands.
Thus advantageously, the present invention provides for client self-monitoring for adjusting individual resource allocation and configuration on-the-fly for optimized resource allocation in real time and with operating costs and energy use minimized.
While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. It is intended that all such variations and modifications fall within the scope of the appended claims. Examples and drawings are, accordingly, to be regarded as illustrative rather than restrictive. | A shared resource system, method of optimizing resource allocation in real time and computer program products therefor. At least one client device includes an optimization agent monitoring resource usage and selectively suggesting changes to resource configuration for the client device. A management system, e.g., in a cloud environment selectively makes resource capacity available to client devices and adjusts resource capacity available to client devices in response to the optimization agent. Client devices and provider computers connect over a network. The client devices and provider computer pass messages to each other over the network. | 8 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is related to application Ser. No. 566,879, filed Apr. 10, 1975 entitled "Sickle Bar Mower Mounting Apparatus" by Robert Sorensen and Paul C. Gordon and to application Ser. No. 566,878, filed Apr. 10, 1975 entitled "Pitman Mower" by Robert Sorensen, Paul C. Gordon, and Richard A. Zablocki, both of the above applications being filed concurrently herewith and assigned to the assignee hereof.
BACKGROUND OF THE INVENTION
This invention relates to cutterbar mowers of the highway and agricultural type and, more particularly, to a novel cutterbar control system therefor wherein a single structure performs the combined functions of draft means, lift means, and may further perform the function of breakaway means.
THE PRIOR ART
Most mowers in commercial use comprise a drag bar connected at one end to a hitch frame which in turn is connected to the tractor, a pull bar which connects the intermediate portion of the drag bar to the hitch frame to provide a draft means, a lifting linkage which rotates the cutterbar about the end of the drag bar to a "gag" position, wherein the inner end of the cutterbar is on the ground and the outer end is off the ground and then raises the entire drag bar and cutterbar off the ground, the linkage usually including a float spring to counterbalance a portion of the weight of the cutterbar, and a breakaway mechanism to allow the cutterbar and the drag bar, in most cases, to rotate rearwardly when the cutterbar strikes an obstruction. Examples of these various functional elements may be found in the Hurlburt et al. U.S. Pat. No. 3,418,796, which primarily illustrates lifting linkage which does not function as draft means and U.S. Pat. No. 3,407,578, which shows the breakaway mechanism and the draft link which are used in the U.S. Pat. No. 3,418,796, and in the Burton U.S. Pat. No. 2,699,635 illustrating an extendible breakaway link but no lifting means. The problem with utilizing these prior art structures is that providing separate structures to fulfill these various functions adds to the complexity and weight of these mowers.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the invention described herein to provide a cutterbar control system for a mower wherein a single structure is utilized to provide the draft, lifting, and breakaway functions.
In accordance with the invention, the mower is provided with a hitch frame for attachment to a vertically movable tractor hitch, the mower drag bar being mounted for pivotal movement to one side of the hitch frame, usually the left side. A pull bar, preferably extendible in response to overload forces on the cutterbar, interconnects the opposite side of the hitch frame with the intermediate portion of the drag bar, the pull bar being mounted for rotation about an axis generally longitudinal thereof. The mounting of the pull bar to the hitch frame preferably is universal to permit lateral and vertical swinging movement of the pull bar, the mounting of the pull bar to the drag bar being similar. The cutterbar gag link, which pivots the cutterbar vertically about the end of the drag bar, is connected to the pull bar remote from the rotational axis thereof. The float spring and lifting chain are also connected respectively to the pull bar and are disposed to rotate the pull bar against the load imposed by the gag link.
BRIEF DESCRIPTION OF THE DRAWINGS
Thus, in accordance with our invention, a very simple arrangement for controlling the positioning of a mower cutterbar is provided which results in a light weight and relatively inexpensive structure, as will be apparent to those skilled in the art upon examination of the drawings, in which:
FIG. 1 is a rear view of a portion of a tractor and a mower incorporating the novel aspects of our invention, the mower being illustrated in the operating position;
FIG. 2 is a partial rear view of the mower of FIG. 1 illustrating the pull bar in the gag position;
FIG. 3 is a top view of the tractor and mower of FIG. 1 in the operating position;
FIG. 4 is a side view, partly in section, of the tractor and mower of FIG. 1 illustrating the mower in the operating position, the gag and lift position being illustrated in phantom;
FIG. 5 is a transverse longitudinal sectional view of the pull bar assembly taken along the line 5--5 of FIG. 4; and
FIG. 6 is a sectional view of the pull bar assembly taken along the line 6--6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the conventions of the industry, directional terms, such as "left", "right", "fore", and "aft", are to be considered as viewed by one standing behind the tractor and implement and facing them.
Turning to the drawings, there is shown the rear portion of a conventional agricultural tractor generally designated 10, including a right ground wheel 11, which is provided with a vertically movable, three point, free link hitch linkage in accordance with the art including a pair of left and right lower hitch links 12 and 14 respectively and an upper center link 15 pivotally mounted at their forward ends to the tractor 10 for vertical swinging movement. A pair of lift links 16 are pivotally mounted respectively to the lower hitch links 12 and 14 intermediate their ends and extend upwardly to pivotal connections to the powered tractor lift arms 17 which rotate in a vertical plane to raise and lower the hitch links. The tractor is provided with a standard power take-off means to which may be connected an extendible PTO shaft 19 for driving associated implements such as our mower.
The mower comprises an inverted U-shaped hitch frame or bail 20 of rectangular cross section having a generally upright transverse orientation. Integrally mounted to the forward side of the top center portion of the bail 20 is a clevis 21 to which is pinned the rearward end of the upper hitch link 15. Each of the legs of the bail 20 are provided respectively with an outwardly extending pin 22 which receives one of the lower hitch links 12 and 14, the pins 22 being arranged along a common axis. The hitch links thus maintain the bail 20 in an upright position while enabling it to be moved vertically. The left leg of the bail 20 extends downwardly from the pin 22 to a horizontal mounting plate 24 and the right leg extends downwardly to a horizontal mounting plate 25, which is at a higher level to accommondate the geometry of the lifting linkage as may be seen in FIG. 1.
The mower further comprises coupling means including a drag bar 30 and cutterbar 61 which, in the normal operating position, extend transversely, or parallel to the bail 20, in a generally horizontal plane. The left end of the drag bar 30 is provided with a U-shaped channel member 31 welded thereto and having an open right side, the member 31 extending forwardly towards the bail 20 but not touching it. As is discussed in detail in the referenced copending application Ser. No. 566,879, which is incorporated by reference herein, a fore-and-aft extending steel leaf spring 32 to inhibit vibration transfer to the tractor is attached at its rearward end to the channel member 31 as by bolts and is bent away therefrom to permit relative movement. The forward end of the leaf spring 32 is wrapped around and tightly clamped as by bolt assembly 34, to a bushing 35 which is mounted for free rotation on a vertical pin 36 to provide a vertical pivot axis for the entire drag bar assembly 30, the pin 36 depending downwardly from the left mounting plate 24, a nut and washer retaining the bushing 35 on the pin 36. The leaf spring 32 has its major cross sectional dimension in the vertical direction, thereby providing its major resiliency in the transverse direction. To permit a small amount of pivoting of the drag bar 30 relative to the bail during the lifting operation, the leaf spring also is capable of torsional deflection on the order of about 5° either way.
A generally fore-and-aft extending pull bar assembly 40, interconnects the right leg of the bail 20 with the intermediate portion of the drag bar 30, thereby forming a draft link. The connection between the forward end of the pull bar assembly 40 and the bail 20 is accomplished with a threaded hook 41 depending downwardly from the right horizontal plate 24, a nut drawing the free end of the hook 41 up into close proximity to the plate 24 transverse of the threaded shank thereof. The hook engages a U-shaped eye member 42 welded to the side of the forward portion of the pull bar assembly 40 and extending diagonally above the center thereof in the operating position, thereby forming a knee 43 at the corner of the pull bar assembly, the axis of the U-shaped eye being in the transverse plane. As thus constructed, the hook 41 permits universal pivoting movement of the pull bar assembly 40 about a pivot connection radially offset therefrom. The rearward end of the pull bar assembly 40 is provided with an oval shaped eye member 44 having a transverse opening which extends radially downwardly and rightwardly from the pull bar assembly 40 to produce an offset pivot connection with a threaded hook 45 which is mounted to and drawn up against, as by nut 47, an upstanding plate 46 affixed to the drag bar 30, the opening of the hook 45 being fore-and-aft. As thus constructed, the hook 45 permits universal pivoting movement of the pull bar assembly 40 thereabout.
Examining the pull bar assembly 40 in greater detail, as best seen in FIGS. 5 and 6, it can be seen that it comprises an outer tube 401 of U-shaped channel section, the eye member 42 being welded at the forward end thereof to the web portion of the U. A breakaway bar 402 having the oval eye member 44 as an integral part thereof slidably fits within the outer tube 401 for longitudinal movement therein, the breakaway bar 402 being of generally rectangular section of a size wherein its major dimension is slightly smaller than the distance between the legs of the channeled outer tube 401. The forward end of the breakaway bar 402 has a thicker section including a surface 403 which slides against the inner side 404 of the web portion of the channeled tube 401. Rearwardly of the surface 403, the breakaway bar 401 steps down to a smaller width forming a ledge 405, the width of the breakaway bar then being constant to its rear end. The outer tube 401 is provided with a guide plate 406 enclosing the fourth side for a distance at the rear end thereof. A stop block 407 is mounted to the web of the tube 401 opposite the guide plate 406 to prevent the breakaway bar from being pulled completely out of the outer tube 401 by the contact of the ledge 405 and the block 407.
Near its forward end, both legs of the channeled outer tube 401 are provided with a V-shaped cutout 409, a plate 410 being welded to the outer tube 401 to cover each of the cutouts 409. A detent pin 411 extends between the plates 410 and is of a length greater than the distance between the legs of the outer tube so that it may be guided in the cutouts 409. The forward end of the breakaway bar 402 is tapered to be small enough to clear the pin 411 at the bottom of the cutouts 409. Behind the tapered portion of the breakaway bar 402 and in register with the cutouts 409, a detent pocket 412 having a depth somewhat greater than the radius of the pin 411 is provided to receive the pin. A detent lever 414 is provided with a similar detent pocket 415 which fits on the other side of the pin 411 from the pocket 412. It can be seen from FIG. 5, that the detent pockets 412 and 415 form portions of the sides of a square, the square being rotated about 10 degrees clockwise from parallel with the edges of the outer tube 401. This rotation or angling of the detent pockets permits the pin 411 to roll out of the pocket 412 when the breakaway bar 402 is pulled rearwardly.
The detent lever 414 diagonals outwardly to the outside of the guide plate 406 and extends rearwardly to an end having an inturned lug 416 which fits within a pocket 417 formed on the outer side of the guide plate 406. Intermediate its ends, the detent lever 414 is provided with a hole through which a spring support pin 419 extends from the guide plate 406 to a threaded end. A compression spring 420 having retaining washers 421 at either end is mounted about the support pin 419, an adjusting nut 422 being screwed down on the pin to compress the spring 420, thereby setting the preload against the detent pin 411.
Thus, as shown in phantom in FIG. 5, when a sufficient force is applied to the end 44 of the breakaway bar 402, the pin 411 is forced upwardly by the angled detent pocket 412 in the breakaway bar against the detent lever 414 which is loaded by the spring 420 and rolls out of the detent pocket 412. The pull bar assembly 40 may then extend until the ledge 405 on the breakaway bar 402 contacts the stop block 407 on the outer tube 401.
The drag bar 30 extends rightwardly from the pull bar assembly 40 to a vertical cutterbar mounting plate 38 outboard of the tractor wheel 11. A hinge member 60 is bolted to the mounting plate 38 and extends downwardly to a bifurcated end whereat a transversely extending mower cutterbar 61 having hinge ears 62 is pivotally mounted thereto by pins 63 and 64 having a common fore and aft axis to provide for vertical swinging of the cutterbar 61 thereabout. The cutterbar 61 is of conventional design and is provided with an inner gaging shoe 65 and an outer gaging shoe (not shown). Mounted on the forward side of the cutterbar are a conventional transversely reciprocating sickle 66 and mower guards 67.
As may be seen in FIGS. 1 and 2, the pull bar assembly 40 may rotate about an axis generally longitudinal thereof but slightly skewed therefrom which extends between the hooks 41 and 45. This action enable the pull bar assembly 40 to become part of the lifting linkage for the mower. To this end, the pull bar assembly 40 is provided with a radial lever arm 48 welded to the outer tube 401 near the rear end thereof. A float spring 49 and a lift chain 50 are connected to the lever arm 48 by pin and clevis assemblies, the spring being closer to the axis of the pull bar 40 than the lift chain. As may best be seen in FIG. 4, the opposite ends of the float spring 49 and lift chain 50 are connected to the rear end of a rocker lever 51 pivotally mounted on a transverse pin 511 mounted in a bracket 512 welded to the upper portion of the bail 20 vertically above the pull bar assembly 40, the lift chain 50 being connected to the rocker lever 51 further from the fulcrum pin 511 than the float spring 49 to provide it with additional mechanical advantage. The lower edge 513 of the lever 51 is positioned to the bottom of the bracket 512 to provide a stop against the downward travel of the lever 51 caused by the float spring 49 and lift chain 50. The forward end of the lever 51 is connected by a chain 52 to the intermediate portion 53 of the lower hitch link 14, the chain 52 being just taut at the position of the hitch links where gagging is to begin. The chain 52 could be attached to a fixed point on the tractor, such as the draw bar, if a greater amount of lifting is desired.
A gag link 54 comprising an elongated rod with hooked ends is pivotally connected to the upper portion of the oval eye member 44 away from the hook 45, that is, away from the axis of rotation of the pull bar assembly 40, and extends transversely whereat it is pivotally connected to the upper end of a lift lever 55 pivotally mounted to the cutterbar 61 as at 56, a medial portion of the lift lever resting on the hinge ear 62 of the cutterbar 61 to provide a fulcrum point therefor. Thus, as shown in phantom in FIG. 1, a leftward pull on the gag link 54 will cause the cutterbar 61 to pivot about the pins 63 and 64 raising the outer end of the cutterbar.
The mower drive means comprises an upstanding transverse plate 70 mounted on the drag bar 30 between the leaf spring 32 and the pull bar assembly 40. A bearing housing 71 is bolted to the lower part of the forward side of the plate 70 and extends therethrough. A shaft 72 is journalled in the housing 61 and extends forwardly whereat a flywheel 73 having a sheave is mounted thereon. The forward side of the flywheel 73 is provided with means 74 such as a pin and bearing housing for pivotally attaching a pitman stick 75 thereto, the flywheel being counterweighted against the weight of the mounting means 74 and about half of the weight of the pitman stick 75 in accordance with the art. The pitman stick 75 extends transversely downwardly to a pivotal connection with the sickle 66 as at 76. A journal arm 77, on which is journalled an input drive sheave 79, is pivotally mounted to the upper portion of the plate 70 about pin 80. The journal arm 77 is provided with an arcuate slot 81 concentric about the pin 80 through which a bolt may be inserted into the plate 70 to maintain the journal arm 77 in position. A J-bolt 82 hooks into the journal arm as at 84 and extends through an outturned edge of the plate 70 whereat it is provided with a nut 85 which may be used to tension a belt 86 extending around the drive sheave 79 and the sheave on the flywheel 73. A stub shaft 87 extends forwardly from the drive sheave to a universal joint assembly 89 providing a power connection with the PTO shaft 19.
THE OPERATION OF THE PREFERRED EMBODIMENT
In the normal operating position, as shown in solid lines in FIGS. 1, 3, and 4, the lower surface 513 of the rocker lever 51 is in contact with the mounting bracket 512 (FIG. 4). In this position, the lift chain 50 is slack to allow the mower to follow ground variations. The rocker arm actuating chain 52 is also untensioned. The float spring 49 is under tension and acts on the lever arm 48 to cause a torque on the pull bar assembly in a counterclockwise direction, as viewed in FIG. 1, thereby counterbalancing a portion of the weight of the outer end of the cutterbar 61 which acts through the gag link 54 to cause a torque on the pull bar assembly 40 in the clockwise direction. The float spring also counterbalances a portion of the weight of the inner end of the cutterbar by the vertical lifting force exerted on the drag bar through the hook connection at the rear end of the pull bar. Thus, the weight of the drag bar, the drive means, and the cutterbar will be counterbalanced to ride more lightly over the ground, thereby reducing ground friction as is desirable in mowing applications.
When the three point hitch linkage of the tractor is raised to move the mower to the gagged position, the distance between the intermediate point 53 on the lower hitch link 14 and the top of the bail 20 increases. This causes the chain 52 to be put into tension and pulls the forward end of the rocker lever 51 down in turn tensioning the chain 50 and causing the lever arm 48 and the pull bar assembly 40 to be rotated counterclockwise about the axis between the hooks 41 and 45 as viewed from the rear. Since the lift chain 50 is connected to the rocker lever 51 further away from the pin 511 than the float spring 49, the tension on the spring becomes lessened. Continued raising of the hitch rotates the pull bar assembly until the knee 43 of the U-shaped member 42 rotates up to contact the bottom side of the horizontal plate 25. This rotation also causes the oval eye member 44 to rotate clockwise about the hook 45 exerting a leftward pull on the gag link 54 which raises the outer shoe of the cutterbar off the ground. In FIG. 2, the pull bar is shown in the gagged position and it will be noted that, due to the radial offset of the eyes 42 and 44, the pull bar 40 has skewed from the axis of rotation. In viewing FIG. 4, it can be seen that the pull bar also rotates relative to the hooks 41 and 45 in the vertical fore-and-aft plane to allow the inner shoe 65 of the cutterbar to remain on the ground. When the knee 43 of the U-shaped eye 42 contacts the horizontal plate 25 on the bail 20, further rotation of the pull bar assembly is stopped with the mower in the gagged position. At this point, continued lifting of the three point hitch links will raise the inner shoe 65 off the ground and the entire cutterbar 61 and drag bar 30 to the uppermost phantom position shown in FIG. 4 for transport purposes. Since the rear end of the lever 51 continues to move upwardly relative to the bail 20, the lifting chain 50 pulls the pull bar assembly 40 into a more nearly horizontal position.
It is noted that when the hitch bail 20 is raised to rotate the pull bar assembly 40 to the gagged position, the left side of the hitch bail 20 raises the left end of the drag bar 30 to a greater angle relative to the ground, the inner shoe 65 remaining thereon. This is compensated in the left end of the drag bar by permitting torsional deflection of the spring 32 of about 5°. As indicated above, further lifting beyond the gagged position will cause the drag bar to be more nearly horizontal.
In the normal operating position, the mower and drag bar are free to oscillate in the transverse direction parallel to the hitch frame to the extent permitted by the leaf spring 32, the pivots at 36, 41, and 45 permitting this movement. Should the mower encounter a fixed obstruction such as a tree stump, sufficient load, in excess of about 400 pounds at the outer end of a 7 foot cutterbar, will be generated to overcome the detent spring 420 in the pull bar assembly 40 and enable the pull bar 40 to extend thus causing the entire drag bar assembly 30 to pivot backwards about the pivot point 36. The extension of the pull bar 40 takes place between the connection of the gag link 54 thereto and the lever arm 48 preventing adverse loading of the float spring 49 and lift chain 50.
Thus, it is apparent that there has been provided in accordance with the invention a cutterbar control system that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in the light of the foregoing description. For example, the float spring 49 and lifting chain 50 could be connected directly to the bail 20 rather than through the rocker lever 51 as described. This would reduce the distance that the cutterbar is lifted for the same change in the position of the bail 20. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. | A cutterbar control system for an agricultural or highway mower having a longitudinally rotatable pull bar connecting the tractor hitch frame and the drag bar. The cutterbar gag link is connected to the pull bar at a point removed from its axis of rotation and a float spring and lifting chain are mounted to the pull bar to rotate it against the load imposed by the cutterbar gag link. The pull bar is extendible in response to overloads imposed on the cutterbar. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to amino resin compositions for mold cleaning, and more particularly, to an amino resin composition formed by adding a semi-cured amino resin or semi-cured mixture thereof to a thermosetting resin.
BACKGROUND OF THE INVENTION
[0002] A thermosetting resin such as epoxy resin is normally used as a encapsulating material in a molding process for electronic circuits and semiconductor devices e.g. integrated circuit (IC), large scale integrated circuit (LSIC), transistor and diode. For continuously performing the molding process, a mold may be easily contaminated with the residual resin material. If such a mold is not cleaned prior to the next molding process, an encapsulant formed during molding can be contaminated with the residual resin material, or undesirably adhered to the mold to be hardly removed; this therefore significantly degrades quality of forming the encapsulant. Accordingly, it is important to clean the mold periodically in a manner that, after performing hundreds of times of the molding process, the mold needs to be cleaned by using a cleaning resin, so as to keep surfaces of the mold free of contaminant, and allow the molding process to be smoothly proceeded.
[0003] A conventional resin composition for mold cleaning is an amino resin composition, a type of thermosetting resin. Such a resin composition is made in tablets for use to clean a molding device adopted for fabricating semiconductor or IC elements. In practice use, the resin tablets are preheated to a temperature from 80° C. to 120° C., and then injected to fill the mold. After the resin is cured in the mold, contaminant can be removed together with the hardened resin from the mold, so that the mold cleaning purpose can be achieved.
[0004] In accordance for use with various molding devices, the tablets of the resin composition are dimensionally made in diameter within the range of from 10 to 70 mm. In production of the resin tablets by using a tablet-forming machine, it usually causes abrasion to th machine, and thus a super steel material is preferably used to overcome the abrasion problem. This therefore not only increases production costs, but also undesirable noise is generated due to surface friction between the tablets when the tablets are removed from the machine. Also, if the resin composition is not good to be made in tablets, the tablets are easily formed with cracks, thereby degrading the production yield of the tablets.
[0005] For example, Japanese Patent Publication Sho 64-10162 discloses a resin composition for mold cleaning which consists of a condensed resin of amino resin and phenol resin, and a mineral powder with hardness of 6 to 15 on the new Mohs' scale. Japanese Patent Publication Sho 52-788 discloses a method for cleaning a contaminated mold surface through the use of an amino-resin based material, and a resin for mold cleaning consisting of an amino-resin composition, an organic base or inorganic base, and a releasing agent. The Japanese Patent Publication Sho 52-788 is charactized in increasing an amount of the releasing agent used in the resin for mold cleaning, for allowing the resin to be more stably made in tablets and increasing yield thereof. However, in practical use, the releasing agent may leak out from the resin and thus cause contamination to the mold, thereby making the mold further contaminated but deteriorating the mold cleaning effect. Moreover, Taiwanese Patent No. 343171 discloses a small tablet of amino-resin composition; however, such tablets have a rapid setting rate, which limits the cleaning efficacy thereof. As a result, it needs to increase the cleaning frequency, so that costs and time for mold cleaning are both raised. Therefore, it is critically desired to find a resin composition that is easily made in tablets and good in cleaning ability.
[0006] The objective of the present invention is to provide an amino resin composition that the mold cleaning ability of the resin composition can be enhanced. Such a resin composition is made with increase in the apparent density, allowing its mold cleaning ability to be well assured even with addition of a releasing agent, as well as allowing the resin composition to be stably formed in tablets.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] In order to accomplish the above and other objectives, the present invention proposes an amino resin composition for mold cleaning, which is formed by firstly adding a specifically-made semi-cured amino resin composition or a semi-cured mixture thereof to a general thermosetting resin, and then the mixture is pulverized, kneaded and homogeneously mixed with a xylene fiber material, inorganic filling material, releasing agent and promoter. The resulted amino resin composition can be made into tablets directly and stably no matter in the form of large tablets that are preheated for use, or in the form of small tablets that can used instantly without being preheated. Such an amino resin composition is also advantageous for its high production yield of tablets and excellent mold cleaning ability.
[0008] The amino resin used in the invention is a general amino resin such as malamine and the like.
[0009] The specifically-made semi-cured amino resin and a semi-cured mixture hereof used in the invention contains at least one methylol group, for example, malamine-aldehyde resin, malamine-phenol-formaldehyde resin, malamine-urea-formaldehyde resin, urea-formaldehyde, and the like. In a method for manufacturing the semi-cured amino resin, an amino compound such as urea and malamine, or a derivative thereof is heated and refluxed under stirring in the presence of a catalyst with formaldehyde or a derivative thereof, and optionally phenol or a derivative thereof, so as to form a semi-cured amino resin such as urea-formaldehyde resin, urea-phenol-formaldehyde resin, malamine-formaldehyde resin and malamine-phenol-formaldehyde resin. In the foregoing reaction, the molar ratio of formaldehyde or a derivative thereof (hereinafter designated as F) to the amino compound (hereinafter designated as M), i.e. F/M, is necessarily greater than 1.0, so as to initiate a cross-linking setting reaction in the condition of formaldehyde (F) acting as a cross-linking agent to be greater in amount than urea or malamine (M) in the resin. The ratio F/M can be within the range of from 1.0 to 6.0, preferably from 1.0 to 2.5. With the addition of phenol or a derivative thereof (hereinafter designated as P), the molar ratio ((P+F)/(M)) of a sum (P+F) of phenol or a derivative thereof and formaldehyde or a derivative thereof to the amino resin (M) is within the range of from 1.0 to 6.0, preferably from 1.0 to 2.5.
[0010] The catalyst used herein can be a basic material such as oxide or hydroxide of Group I or Group II alkali or alkali metal, amine aqueous solution, other amines, and the like. The catalyst can be used alone or as a combination of two or more thereof. The usage amount of the catalyst is preferably ≦5%, based on the total weight of reactants.
[0011] The temperature of the reaction can be in the range of from 50° C. to 100° C. The reaction is to obtain a semi-cured amino resin; therefore when gel time of the reactants reaches a predetermined time, the reactants are dried under reduced pressure to stop the reaction, wherein dryness is adjusted in extent to control water content according to desired solid content. Preferably, the solid content is 75% or more, and more preferably 85% or more. This results in a semi-cured amino resin having at least one methylol group, with solid content of 75% or more. The gel time is measured as the time for stirring a resin on a hot plate without forming filamets, according to the JIS K6909 method.
[0012] As compared to a conventional dry method, the reaction process of the invention requires neither expensive solid amino resin nor an additional organic solvent that is used in a wet method. Thus, a procedure for drying to remove the solvent is omitted, and contamination caused by the volatilization of the organic solvent can be avoided, as well as costs can be reduced.
[0013] The amino resin composition for mold cleaning of the invention therefore includes the foregoing obtained semi-cured amino resin having at least one methylol group, together with other thermosetting resin and additives, are stirred and mixed homogeneously in a semi-cured manner in a device such as a kneading machine, ball mill, tumble, rapid mixer and the like. Then, the mixture is charged into a roller, or a single or double-shaft presser for compounding. After the semi-cured amino resin cross-links, it is cooled and pulverized into particles or powders by using a pulverizer, so as to obtain the amino resin composition for mold cleaning of the invention.
[0014] The additives mentioned above can be, for example, pulp, wood powder fiber material, inorganic filling material, releasing agent, hardening promoter, and the like.
[0015] A method for making the amino resin composition for mold cleaning of the invention is to heat and compound the semi-cured amino resin or a semi-cured mixture thereof having at least one methylol group with solid content of more than 75% alone, or to heat and compound it with other thermosetting resins together, and then under a semi-cured condition, other additives are added to allow the semi-cured amino resin to polymerize into an amino resin material having a higher molecular weight. Such a material with higher molecular weight is the amino resin composition used for mold cleaning as proposed by the invention. Since the method of the invention has the advantages but not the disadvantages of conventional dry or wet methods, wherein the drying procedure in the wet method can be omitted, and the volatilization of a large amount of toxic odorous solvents can be avoided. Moreover, the invention does not use expensive raw materials as in the dry method, and thus the cleaning problems caused by transporting powders of the raw materials can be avoided. Therefore, since the method of the invention is simple in process without the use of organic solvents, thus it is beneficial both economically and environmentally.
[0016] The general thermosetting resin used in the invention is normally added in an amount of about 30 to 60 wt %, preferably about 40 to 50 wt %, of the total weight of the amino resin composition.
[0017] The added amount of the semi-cured amino resin or a semi-cured mixture thereof used in the invention is in the range of about 40 to 70 wt %, preferably about 50 to 60 wt %, of the total weight of the amino resin composition.
[0018] The paper or wood powder fiber material used in the invention preferably has 80 wt % or more, more preferably 95 wt % or more, of particles passing through No. 80 screen. The added paper or wood powder fiber material is in the range of 10 to 80 wt % of the total weight of the amino resin composition.
[0019] The inorganic filling material used in the invention includes compounds of metal, such as silicon, iron, titanium, sodium, calcium, chromium, manganese, boron, aluminum, or the like; for example, oxides or hydroxides (such as magnesium oxide, calcium oxide, zinc oxide, manganese oxide, aluminum oxide, silicon oxide, silicon dioxide, aluminum hydroxide, magnesium hydroxide, or the like), sulfates and sulfides of metal (such as calcium sulfate, barium sulfate, zinc sulfide, or the like), metal silicates (such as magnesium silicate, calcium silicate, or the like), carbides (such as silicon carbide, and the like), mineral powders (such as carborumdum, corundum powder, talc powder, diatomaceous earth, kaolin, talc powder, silica, sakura stone, or the like), or glass fibers (the ratio L/D of glass fiber length L to glass fiber diameter D is 5000 or less). The added inorganic filling material is in the range of 0.01 to 80 wt %, more preferably 10 to 48 wt %, of the total weight of the amino resin composition.
[0020] The mineral powder suitably used in the inorganic material mentioned above can include, for example, natural mineral such as carbordum, corundum powder, talc powder, diatomaceous earth, kaolin, talc powder, silica, sakura stone or the like, and oxide or carbide of silicon, iron, titanium, sodium, calcium, chromium, manganese, boron, aluminum or the like. The average particle size of the powder is preferably under 150 μm, more preferably under 100 μm, and most preferably under 40 μm.
[0021] The releasing agent useful in the invention includes aliphatic releasing agent (such as stearic acid, zinc stearate, magnesium stearate, calcium stearate, butyl stearate), aliphatic amido releasing agent (for example saturated or unsaturated monoamide type of releasing agents such as dodecyl amide, tetradecyl amide, oleamide, stearamide, or the like, and saturated or unsaturated diamide type of releasing agents such as dioleamide, distearamide, or the like), alcoholic releasing agent (such as polyethylene glycgl 400 (PEG400), PEG1000, high alcohol), paraffinic releasing a (which is mainly linear carbohydrate having 28 to 90 carbons, for example, liquid paraffin, paraffin, paraffin wax, Sasol Wax, or the like), and silicic releasing agent (such as silicon oil). The added amount of the releasing agent is from 0.01 wt %, to 10 wt %, preferably from 1.5 to 5.0 wt %, based on the total weight of the amino resin composition. In the case of fatty acid metallic salt (such as zinc stearate, magnesium stearate, and calcium stearate), the added amount thereof can be from 0.5 wt % to 10 wt %, whereas in the case of fatty acid (such as stearic acid, and butyl stearate), the added amount thereof can be in the range of 0.01 wt % to 0.1 wt %, so as to improve the quality and yield of tablets, and to assure stability and mold cleaning effect of the amino resin composition. If the added amount of the above releasing agent is not sufficient, the amino resin composition is not capable of entirely filling a mold, thereby resulting in poor cleaning effect. Also, the hardened amino resin composition can be adhered to the mold surface due to poor in releasing ability, this further deteriorates the mold cleaning efficacy.
[0022] The hardening promoter useful in the present invention includes inorganic acidic hardening promoter (such as sulfuric acid, boric acid, phosphorous acid, hydrochloric acid, and the like), organic acidic hardening promoter (such as oxalic acid, benzoic acid, phthalic anhydride, p-toluene sulfonic acid, and the like), organic ammonium salt hardening promoter (the salts formed from the above acids and tiethanolamine, triethylamine, 2-methyl-2-amino-1-propanol, or the like, are for example, CATANITTO, CATANITTO-A, or the like), and inorganic metal salt hardening promoter (such as zinc sulfite or the like). The added amount of the hardening promoter is from 0.01 to 10 wt %, based on the weight of the amino resin composition.
[0023] The amino resin composition for cleaning molds of the present invention can be made into tablets, platelets, or powder, and is effective in mold cleaning.
[0024] The examples and comparative examples are exemplified as follows and describe in more detail the present invention, but they should not be construed to limit the scope of the present invention.
[0025] Gel Time measured in the above specification and examples is the time when the resin stirred on a hot plate (measured under 150° C.) does not form filaments, according to the method of JIS K6909.
[0026] The rate of curing the amino resin composition of the present composition (T90 value) is in the range of from 450 seconds to 750 seconds and is measured as follows:
[0027] The method of the measurement for the rate of setting (T90 value):
[0028] The commercial JSR type of setting meter is used. When the temperature of the surface of a mold is kept at 145° C., the mold is subjected a vibration with a certain amplitude and deforms. The change of the stress of the amino resin composition for cleaning molds is monitored according to the elapsed time for setting. The time required is T90 value (seconds) when the change of the stress reaches 90% of the maximum value.
[0029] The present invention is illustrated by the following example.
EXAMPLE 1
[0030] 310 weight part of malamine, 130 weight part of phenol, 540 weight part of 37% formaldehyde aqueous solution, and 5 weight part of calcium hydroxide were added into a flask. After the mixture was heated and refluxed under 80° C. for 30 minutes, it was cooled to 45° C., followed by heating and refluxing under 85° C. for 60 minutes. Then, the reaction mixture was neutralized with 10% sodium hydroxide solution and dried under vacuum, so as to obtain a semi-cured amino resin of malamine-phenol-formaldehyde having 85% of solid content and gelation time of 4 minute and 30 second (measured under 150° C.).
[0031] 20 wt % of the semi-cured amino resin, 50 wt % of malamine resin, 20 wt % of silica powder with mean particle size under 20 μm, 1.82 wt % zinc stearate, 0.08 wt % of PEG400, 8 wt % of paper pulp, and 0.1 wt % of benzoic acid, based on 100 wt % total weight of resin composition, were homogeneously pulverized and mixed by a ball mill. Alternatively, other means could be used to pulverize and sufficiently homogenize and mix the components. A resin composition for cleaning molds was obtained.
EXAMPLE 2
[0032] 25 wt % of the semi-cured type of malamine-phenol-formaldehyde amino resin as in example 1 and 10 wt % of paper pulp, based on 100 wt % total weight of resin composition, were mixed and kneaded to give the semi-solidifying mixture. Then 45.7 wt % of malamine resin, 17 wt % of silica powder with mean particle size less than 20 μm, 1.8 wt % zinc stearate, 0.2 wt % of benzoic acid, and 0.2 wt % of CATINITTO were added to the mixture, to be then homogeneously pulverized, and mixed by a ball mill. Thereafter, 0.1 wt % of PEG400 was further added and subjected to a last stage of mixing. A resin composition for cleaning molds was obtained.
EXAMPLE 3
[0033] 340 weight part of malamine, 100 weight part of urea, and 550 weight part of 37% formaldehyde aqueous solution were poured into a flask. After the mixture was heated and refluxed at a temperature of 70° C. for 50 minutes, it was allowed to cool to 50° C., after which, it was heated and refluxed again at a temperature of 100° C. for 100 minutes, then dried under a vacuum. A semi-cured type of amino resin of malamine-phenol-formaldehyde having 85% of solid content and a gelation time of 5 to 6 minutes (measured under 150° C.) was obtained.
[0034] 30 wt % of the semi-cured substance, 48 wt % of malamine resin, 20 wt % of silica powder with mean particle size less 20 μm, 1.8 wt % zinc stearate, 0.08 wt % of PEG400, 8 wt % of paper pulp, and 0.12 wt % of benzoic acid, based on 100 wt % total weight of resin composition, were homogeneously pulverized, kneaded and mixed by a ball mill. Alternatively, other means could be used to homogeneously pulverize and sufficiently mix the components. A resin composition for cleaning molds was obtained.
EXAMPLE 4
[0035] The same procedures as carrier out in example 1 were repeated, except that 0.1 wt % of benzoic acid in example 1 was deceased to 0.01 wt %. A resin composition for cleaning molds was obtained.
EXAMPLE 5
[0036] The same procedures as carrier out in example 1 were repeated, except that 20 wt %, of the semi-cured substance in example 1 was changed to 30 wt % and 50 wt % of malamine resin was changed to 40 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 1
[0037] The same procedures as carrier out in example 1 were repeated, but releasing agent, zinc stearate and PEG400, were not added and the amount of silica powder was changed to 21.8 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 2
[0038] While the same procedures as carrier out in example 1 were repeated, without the addition of releasing agent, zinc stearate, were not added. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 3
[0039] While the same procedures as carrier out in example 1 were repeated, releasing agent and, PEG400, were not added and the amount of silica powder was changed to 20.08 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 4
[0040] While the same procedures as carrier out in example 1 were repeated, the amount of releasing agent, zinc stearate, as increased to 11.72 wt %. As well, the amount of silica powder was changed to 15 wt %, and the amount of malamine resin, was changed to 15 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 5
[0041] While the same procedures as carrier out in example 1 were repeated, the amount of releasing agent, zinc stearate was changed to 0.72 wt % and the amount of silica powder was changed to 21 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 6
[0042] The same procedures as carrier out in example 2 were repeated, but 20 wt % of semi-cured type of amino resin was decreased to 10 wt % and 49 wt % of malamine resin was increased to 59 wt %. A resin composition for cleaning molds was obtained.
COMPARATIVE EXAMPLE 7
[0043] While the same procedures as carrier out in example 1 were repeated, the amount of zinc stearate was changed to 1.2 wt % and the amount of PEG400 was changed to 0.6 wt %. A resin composition for cleaning molds was obtained.
[0044] The resin compositions or cleaning molds of the above examples and comparative examples were tested as follows for the comparison of the advantages and disadvantages of their mold cleaning ability and their ability to form tablets.
[0045] Test Method 1 Soil removing on the surface of molds
[0046] The surface of molds will be contaminated after moldings in the molding process have been processed more than 1000 times in the mold of the out automated molding machine where commercial epoxy resin molding tablets, for example SUMIKON 7320CR have been used. Therefore it is necessary to use the resin composition to clean the mold. The number of cleanings is recorded and the cleaning effect is evaluated according to the following criteria. In this test method, the temperature of the mold for molding is 180° C., and the time for setting is 180 seconds. The criteria for evaluation is as follows:
[0047] 5: completely no soil residue
[0048] 4: almost no soil residue
[0049] 3: little soil residue
[0050] 2: having soil residue
[0051] 1: much soil residue
TEST EXAMPLE 1
[0052] The soil test for the surface of molds were processed by the procedures as set forth in test method 1, using the resin composition for cleaning molds obtained according to the methods in the examples and the comparative examples, and the effect of cleaning was evaluated according to the standards for evaluation in test method 1. The result is shown in table 1. In light of table 1, it is demonstrated that the resin composition of the present invention has very excellent effect for mold cleaning, which allows it to completely remove the soil on the surface of the mold after 2 to 3 injections when it reaches the evaluation criterion ‘5’, superior to the comparative examples which need 8 to 9 injections to obtain the same effect.
TABLE 1 Soil Removing Test on the Surface of Molds Mold Cleaning Ability of the Resin Composition Number of Mold Cleaning Resin Composition 1 2 3 4 5 6 7 8 9 10 Example 1 3 5 — — — — — — — — Example 2 3 5 5 — — — — — — — Example 3 3 4 5 — — — — — — — Example 4 3 4 5 — — — — — — — Example 5 3 4 5 — — — — — — — Comparative 3 2 2 3 3 4 4 4 5 — Example 1 Comparative 1 1 2 2 2 3 4 4 5 — Example 2 Comparative 1 2 3 3 3 4 4 4 5 — Example 3 Comparative 1 2 2 3 3 4 4 5 — — Example 4 Comparative 2 2 2 3 3 4 4 5 — — Example 5 Comparative 2 2 2 3 3 4 4 4 5 — Example 6 Comparative 2 2 2 3 3 4 4 4 5 — Example 7
[0053] Test Method 2 The effect of mold cleaning for different molding temperatures and times of setting
[0054] The surface of molds will be contaminated when sealed moldings has been proceed for more than 1000 times in the mold of the automated molding machine using commercial epoxy resin molding material tablets, for example, SUMIKON 5050S; therefore it is necessary to use the resin composition for cleaning molds to clean the mold. In this test method, each resin composition for cleaning the mold is used to clean the mold at tempeatures of 150° C., 160° C., 170° C., 180° C., and 190° C., for 180 seconds, 240 seconds, and 300 seconds, respectively. The effect of cleaning is evaluated according to the criteria for evaluation as in test method 1.
TEST EXAMPLE 2
[0055] Each of the resin compositions of the present invention and the comparative examples was used to clean the mold at various temperatures for a period of three setting times: 180 seconds, 240 seconds and 300 seconds. The effect of cleaning was evaluated according to the criteria for evaluation as in test method 1. The result is shown in Table 2. As shown in Table 2, it is demonstrated that the resin composition of the present invention has very excellent effects for mold cleaning. Even when the composition of the present invention sets for 180 seconds or 240 seconds under the lower molding temperature of 150° C. or 160° C., the complete effect of soil removal could be obtained; for conditions of higher temperatures and longer setting time the procedure was even more effective. For the comparative examples, the complete effect of soil removing could not be obtained even under a higher molding temperature of 170 or 180° C., and longer setting time such as 300 seconds; the same effect could be only obtained under higher molding temperature of 190° C., and a longer setting time of 300 seconds. In view of the above, it is demonstrated that the effect of mold cleaning for the composition of the present invention is superior to the comparative examples.
TABLE 2 Soil Removing Test for different mold temperatures and setting times Example No Resin Cleaning Efficacy of the Resin Composition Composition 150° C. 160° C. 170° C. 180° C. 190° C. Example 1 180 Sec. 4 4 5 5 5 240 See. 4 5 5 5 5 300 Sec. 5 5 5 5 5 Example 2 180 Sec. 4 4 5 5 5 240 Sec. 4 5 5 5 5 300 See. 5 5 5 5 5 Example 3 180 Sec. 4 4 5 5 5 240 Sec. 4 5 5 5 5 300 Sec. 5 5 5 5 5 Example 4 180 Sec. 4 4 5 5 5 240 Sec. 4 5 5 5 5 300 Sec. 5 5 5 5 5 Example 5 180 Sec. 4 4 5 5 5 240 Sec. 4 5 5 5 5 300 Sec. 5 5 5 5 5 Comparative 180 Sec. 2 2 2 2 3 Example 1 240 Sec. 2 2 2 3 4 300 Sec. 3 3 4 4 5 Comparative 180 Sec. 2 2 2 2 3 Example 2 240 Sec. 2 2 3 3 3 300 Sec. 3 3 4 4 4 Comparative 180 Sec. 2 2 2 2 3 Example 3 240 Sec. 2 2 3 3 4 300 Sec. 3 3 4 4 4 Comparative 180 Sec. 2 2 2 2 3 Example 4 240 Sec. 2 2 3 3 4 300 Sec. 3 3 3 4 5 Comparative 180 Sec. 2 2 2 2 3 Example 5 240 Sec. 2 2 3 4 4 300 Sec. 3 3 4 4 5 Comparative 180 Sec. 2 2 2 2 3 Example 6 240 Sec. 2 2 3 3 4 300 Sec. 2 3 4 4 5 Comparative 180 Sec. 2 2 2 3 3 Example 7 240 Sec. 2 2 3 4 4 300 Sec. 3 3 4 4 5
[0056] The tablet efficacy of resin composition for cleaning molds of the present invention was evaluated according to the following method.
[0057] Test Method 3 The method of measurement for tablet ability
[0058] 4.5 Grams of resin composition for molding was filled into a mold (180 mm φ×30 mm H), pressurized to 350 Kg/cm 2 , and kept 5 to 20 seconds. Thereafter, the upper mold was removed and the pressure was increased to release the tablet. The time required for producing 100 tablets was calculated to obtain the production rate. The appearance of the tablets made from the process were inspected for any cut or damages in order to calculate the percentage of failure from the number of defective-tablets to evaluate the tablet efficacy of said resin composition.
[0059] Also, the resulting tablets were weighed respectively to obtain the distribution of weight to further evaluate the tablet ability of said resin composition. The criteria of evaluation were as follows:
[0060] {circle over (∘)}: weight error ±0.1 g
[0061] ◯: weight error ±0.5 g
[0062] x: weight error ±1.0 g
[0063] Test Method 3
[0064] The tablet ability of the resin composition for cleaning molds obtained according to the method in the examples and the comparative examples mentioned above was evaluated according to test method 3. The result was shown in table 3. As shown in table 3, it is demonstrated that the resin composition for cleaning molds of the present invention has very excellent tablet ability. The production rate of tablets for the composition of the present invention was 420 to 480 tablets per minute. The percentage of failure was extremely low, only 0 to 1%. The distribution of weight was very sharp and the deviation was less than 0.1 gram. For the comparative examples, the production rate of tablet was only 60 to 180 tablets per minute, the percentage of failure was up to 12 to 18%, the distribution of weight was wide and the deviation was more than 0.5 gram, even more than 1.0 gram. From this result, it can be affirmed that the tablet ability of the composition of the present invention is superior to the comparative examples.
TABLE 3 The tablet ability of the amino resin composition of the present invention Tablet Efficacy of Resin Composition Example No Production Rate Mal Ratio Weight Resin Composition (No. of tablets/min) % Distribution Example 1 480 0 ⊚ Example 2 480 0 ⊚ Example 3 420 1 ⊚ Example 4 480 1 ⊚ Example 5 420 0 ⊚ Comparative Example 1 180 12 ∘ Comparative Example 2 180 13 ∘ Comparative Example 3 60 17 x Comparative Example 4 120 16 x Comparative Example 5 60 18 x Comparative Example 6 120 15 x Comparative Example 7 120 14 ∘ | The present invention provides an amino resin composition for cleaning molds, that said composition is made of a thermosetting resin to which is a semi-cured amino resin composition or a semi-cured mixture thereof is added. The amino resin composition has decreased viscosity and increased tablet ability. When used to remove the soil on the surface of molds, the amino resin composition possesses good forming ability and good mold-cleaning effect so that the time needed for mold cleaning is efficiently decreased and the problem of a powder composition that can not be easily tabletted is overcome due to its excellent tablet ability. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for gripping and conveying sheet-like products, such as sheets, signatures, newspapers, periodicals, or the like.
2. Discussion of the Prior Art
U.S. Pat. No. 4,566,687 discloses a conveying system for transferring newspapers or the like from a moving belt to a series of clamps. In this apparatus, shingled papers are conveyed on a horizontally extending belt and are then seized by clamps continuously moving at a constant transit speed lower than the speed of the belt. Each individual paper is gripped and conveyed in a substantially vertical direction by the clamps.
U.S. Pat. No. 4,498,664 shows an apparatus for removing, from a product stream on a conveyor, flexible flat products, especially printed products. The printed products are conveyed in an imbricated formation, and are bent in a substantially saddle-shaped fashion. The printed products are seized by clamps in a middle portion of the saddle shape. A release of some of the printed products conveyed in a shingled formation causes downward movement of products being gripped into one location.
U.S. Pat. No. 5,042,792 discloses a process and an apparatus for conveying printed products. In a take-over region, the succession of printed products is changed from a first imbricated formation to a second imbricated formation. This changes the product formation during conveying and allows for single product take-up by a clamping device of each product.
SUMMARY OF THE INVENTION
It is an object of the present invention to allow for release of at least two commonly seized products at different release points.
It is a further object of the present invention to simplify the delivery of two side-by-side product streams.
It is another object of the invention to minimize the number of components used in constructing the device, in order to achieve delivery of products at different points.
Finally, it is an object of the present invention to combine the product-releasing options of a two-track conveying system into a single-track conveying system.
In order to implement these and still further objects of the present invention, the apparatus for gripping and conveying sheet-like products of the present invention has: a single conveying track or multiple conveying tracks supporting a gripping device, the gripping device having a support moving within said single conveying track or multiple conveying tracks, gripper devices which seize slit sheet-like products, and gripper devices which are independently actuatable.
The support of the gripping devices may be either slidably mounted on a single conveying track or may contact rotatable guiding devices within the conveying track. The gripping devices are divided in half lengthwise and each of the gripper devices on either side of each gripping device has an actuating element. The actuating element can be a cam interacting with a cam follower, although other arrangements are also possible. Actuation of the cam follower by the cam overcomes a spring force, which spring force maintains the gripper device closed and therefore maintains pressure between the gripper and a corresponding pad.
The gripper devices include a first gripper and second gripper cooperating with a first pad and a second pad, respectively. The first cam follower and a first lever arm are mounted on a first axle of the support, and the second cam follower and a second lever arm are mounted on a second axle of the support. The first and second axles are mounted coaxially within the support of the gripping device.
Furthermore, the first and second axles define the pivoting axes about which the first and the second grippers move, thereby seizing a sheet-like product. The single conveying track or multiple conveying tracks can either extend in a substantially horizontal plane or can be inclined relative to a horizontal plane. Sheet-like products are held between a gripper and a corresponding pad by a spring force. The cam follower and lever arm are actuated by a cam which overcomes the spring force exerted on the gripper.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the present invention will become apparent to those skilled in the art, upon reading the following description of preferred embodiments of the invention, in view of the accompanying drawings, wherein:
FIG. 1 shows a slit ribbon configuration for tabloid folds in a side-by-side arrangement;
FIG. 2 shows a slit ribbon configuration for a double parallel fold;
FIG. 3a is side view of a first embodiment of a product gripping device on a single conveying track;
FIG. 4a is a front view of a product gripping device of FIG. 3a;
FIG. 3b is side view of a second embodiment of a product gripping device on a single conveying track;
FIG. 4b is a front view of a product gripping device of FIG. 3b;
FIG. 5 shows a single or multiple conveying track equipped with fixed and pivotable cam segments;
FIG. 6a shows a side view of a slidably mounted gripping device;
FIG. 6b shows a front view of the device of FIG. 6a.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows a ribbon configuration 1 entering the cylinder part of a folder apparatus. The ribbon 1 has a longitudinally extending slit 3 and is cut into signatures 2. Pin holes 4 are located on the front edge of the ribbon 1. The cut signatures 2 have a trailing edge 6 with pin holes 4 and leading edge 5 which is the first parallel fold made in the folding mode. The product emerging from this folding mode is of a tabloid type 7. The signatures 2 folded in the folding mode have a longitudinal slit 3 dividing the signatures 2 into two portions.
FIG. 2 shows a double parallel fold being processed. As already described above, the ribbon 1 is slit longitudinally; the signatures 2 cut from ribbon 1 have pin holes 4 at their trailing edges 6. The signatures 2, which have a first parallel fold 8, are folded again parallel to fold 8, and thereafter have first and second parallel folds 8, 9. The signatures 10, with a double parallel fold, are seized by a gripper device 11, as shown in FIG. 2. The gripper device 11 conveys the seized product--having a tabloid fold (as with signature 7), a double parallel fold (as with signature 10), or any other fold type--in a conveying direction 12, indicated by the arrow. The gripping device seizes the side-by-side products on either side of the slit 3, so that one portion of the product may be held by the gripper device 11, while the other portion is released, as is described below.
FIG. 3a is a side view of a product-gripping device mounted on a single conveying track. The gripping device 11 includes a support 14, a first gripper 23, a first pad 18, a first axle 17 and a first cam follower 19 mounted on the axle 17. The first axle 17 is mounted within an axle support 25 and forms the pivoting axis for the first gripper 23. The first gripper 23 is pivotable in a direction indicated by the double arrow in FIG. 3a, and cooperates with the first pad 18. The longitudinally-slit sheet-like products are seized between the first pad 18 and the tip of the first gripper 23. The sheet-like products are maintained in position by springs 28, one of which cooperates with first gripper 23 and one of which cooperates with second gripper 24. The first gripper 23 is actuated by the first cam follower 19 mounted on the first axle 17 by way of a lever arm 29. The cam follower 19 is torsionally rigid relative to the first axle 17, so that the axle 17 can be rotated by actuating the first cam follower 19.
A single conveying track, or multiple conveying tracks 13, as shown in FIGS. 3a and 4a, include multiple disc-shaped first and second rolls 15, 16 mounted within the single conveying track or multiple conveying tracks 13. The first and second rolls 15, 16 are spaced from one another in such a way that the support 14 of the gripping device 11 is always supported by a first roll 15 and a second roll 16. The first and second rolls 15, 16 are rotatably mounted within the single conveying track or multiple conveying tracks 13. The track 13 has an upper opening, the width of which corresponds to the width of support 14 of the gripping device.
All of the first and second rolls 15, 16 within the single conveying track or multiple conveying tracks 13 can be driven by a drive. It is possible to have a friction-reducing material on the surface of the first and second rolls 15, 16 and on the bottom of the support 14 to maintain a continuous movement of the gripping device 11 along the single conveying track or multiple conveying tracks 13.
The single conveying track or multiple conveying tracks 13 can be mounted so as to be inclined relative to a horizontal plane. This arrangement causes the gripping devices 11 to move by the effect of gravity. The gripping devices 11 also can be connected together, as links in a chain (FIG. 3a), and driven at one station along the track. In this embodiment, the first and second rolls 15, 16 are mounted rotatably within the single conveying track or multiple conveying tracks 13 and it is only necessary for a few of the rolls 15, 16 to be driven, to compensate for friction losses.
FIG. 4a is a front view of the gripping device according to the present invention. By way of axle support 25, first axle 17 and second axle 20 are rotatably mounted on support 14. The first and second axles 17, 20 are mounted coaxially to one another, yet are independently actuatable. Axle 17 has mounted thereon the first gripper 23, and axle 20 has mounted thereon the second gripper 24. The first and second grippers 23, 24 cooperate with the pads 18, 21. Between the first and second pads 18, 21 and grippers 23, 24, tabloid-type or double parallel fold-type signatures, or other products (see FIGS. 1 and 2) may be seized. One half of the signature 2, divided by the longitudinally extending slit 3, is gripped by the first gripper 23, whereas the other portion of the signature 2 is seized by the second gripper 24. Both grippers 23 and 24 are maintained in their gripping positions by torsional springs 28 assigned to each of the axles 17 and 20. Thus, by gripping two portions of a longitudinally slit product, it is possible to release the portions of the product or signature at different release points. As each of the first and second grippers 23, 24 is actuatable independently from the other gripper, a signature can be released in a very simple manner. The first and second cam followers 19, 22 are actuated by a multitude of different types of actuating elements, in as much as only a small amount of rotation is required for a product release. Such a product release is feasible by way of a first cam segment 26 and a second cam segment 27 attached to the single or multiple conveying tracks 13. The first cam segment 26 acts upon the first cam follower 19, while the second cam segment 27 acts independently upon the second cam follower 22. As both cam segments 26, 27 are arranged at different locations on the single or multiple conveying tracks 13, the release of the portions of the longitudinally slit signatures 2 at different locations can be achieved quite simply.
FIG. 4a also shows the single conveying track or multiple conveying tracks 13 having an opening, the width of which corresponds to the width of the support 14. The support 14 contacts two second rolls 16 which are mounted within the single or multiple conveying tracks 13 and which rolls 16 are rotatable about the axis schematically indicated in dashed lines.
FIGS. 3b and 4b show an alternative embodiment of the device shown in FIGS. 3a and 4a. In this embodiment, the lever arms 29 are actuated by spring-loaded push rods 40. In this embodiment, the cams 26, 27 are located below the tracks 13 and cause the push rods 40 to move upwardly, against the resistance of springs 41, to thereby open grippers 23, 24. In all other respects, however, the embodiment of FIGS. 3b and 4b are the same as the embodiment of FIGS. 3a and 4a.
FIG. 5 shows a single or multiple conveying track arrangement equipped with a fixed and a pivotable cam segment. The gripping device 11, having first and second grippers 23, 24, is moved on the single or multiple conveying tracks 13 in the conveying direction 12. Attached to the conveying track 13 is a fixed first cam segment 26 having two ramps. The ramp arrangement allows for gradual opening or closing of the first gripper 23 to which the cam follower 19 is coupled. By passing the first fixed cam segment 26, the gripper 23 is opened and closed to release one portion of the longitudinally slit signature 2. The same is true of cam 27 and follower 22. It is also possible to provide a pivotable cam segment 30 to act upon the cam followers 19 and 22, respectively. If the release of a product portion is desired at a certain location, the pivotable cam segment 30, which can be on either side or both sides of the track 13, can be moved into its engaged position 30' to act upon the cam follower 19 or the other cam follower 22. In this situation, the first gripper 23 is activated to move against the spring 28 to release the product portion. Movement of the pivotally mounted cam segment 30 is achieved by an actuating unit 32 having an extendable rod member 31. If release of a product portion is not required at a certain predetermined location, the pivotable cam segment 30 stays in its disengaged position.
FIGS. 6a and 6b show an alternative embodiment of the device wherein the device is slidably mounted in the conveying track 13. The support 14 slides in track 13. | An apparatus for gripping and conveying sheet-like products includes a single or multiple conveying tracks for supporting a gripping device, or a series of gripping devices linked in the form of a chain. The gripping device has a support moving within or along a conveying track. The gripping device engages sheet-like products, and includes at least two grippers which are actuatable independently from one another. The grippers allow different portions of the sheet-like products to be conveyed to different locations. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. application Ser. No. 11/518,976, claims the benefit of U.S. Provisional Application No. 60/790, 883, filed on Apr. 11, 2006, both of which are hereby incorporated by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
SEQUENCE LISTING, TABLE OR COMPUTER PROGRAM ON COMPACT DISC
[0003] Not applicable.
FIELD OF INVENTION
[0004] This invention relates generally to a system that directs airflow. More specifically, it relates to an assembly of baffles that directs airflow in a plenum, and a method of using same.
BACKGROUND OF THE INVENTION
[0005] Underfloor air distribution (UFAD) is a method of delivering conditioned air inside offices and commercial buildings. UFAD is an alternative to ceiling-based heating, ventilation and air-conditioning (HVAC) methods. The open space between the sub-floor (usually a structural concrete slab) and the underside of a raised access floor is called the plenum or air handling space. LEAD systems use the plenum to deliver conditioned air into the occupied zones of the building. In a typical UFAD system, conditioned air is emitted by an air-handling unit (AHU), through the plenum and into workspaces via a variety of supply outlets (diffusers) or perforated floor tiles. The AHU is typically located in the plenum or is connected to the plenum via a minimum amount of ductwork. These supply outlets are usually located at floor level (most common), or as part of the furniture and partitions.
[0006] The underfloor plenum is formed by installation of a raised floor system. Usually this raised floor system consists of floor panels supported on pedestals and positioned above the concrete structural slab of the building. The conditioned air, being pressurized vis-à-vis the air above the plenum, typically flows freely in the plenum to the supply outlets or perforated tiles. The plenum thus provides a path for cooled air to travel from the AHU to the workspace. Access to the plenum can be achieved simply by removing one or more floor panels.
[0007] Equipment and data centers are also cooled using the plenum or underfloor air handling space. UFAD systems are particularly advantageous in light of the thermal cooling requirements of computer equipment and data centers. In fact, raised floors were developed in the 1950's and 1960's to facilitate the use and operation of mainframe computers, which required bottom air intake. However, equipment needs have changed in data centers over the past forty years, and servers and other equipment have replaced mainframes in the data center. The servers that have virtually replaced the mainframes can generate more heat than the mainframes in a more concentrated space. Current servers may produce up to six times more heat than the equipment they replace. Hence, data centers have greater cooling requirements than ever before.
[0008] Controlling high temperatures within data centers is very difficult and complex. Yet, keeping computers and data center equipment at the right temperature is critical for the life of the equipment. Such electronic equipment must be maintained in appropriate temperature environments subject to regulated rates of temperature change in order to maintain equipment reliability, abide electronic equipment warranty provisions and ascertain optimum energy usage. Achieving these requirements is an ever constant and evolving concern for the HVAC or IT professional due to the fact that computer and data processing equipment trend toward increasing the amount of power usage, and thus thermal output and cooling demand, over available space. Server manufacturers have used high output fans and enclosed chiller lines to control the high temperatures within data centers.
[0009] Another method of cooling electronic equipment environments and thus meet the thermal demands of computer equipment involves using a dedicated Computer Room Air Conditioner (CRAG) in association with a UFAD system. Electronic equipment, including computer systems, can be cooled using a pressured plenum under a raised floor. Powerful fans in the CRAG units draw in hot air exhausted by equipment in a data center. In a conventional CRAG arrangement, fans cool the hot air by forcing it through a liquid-to-air heat exchanger. With a CRAC-UFAD system, pressurized cooling air enters the plenum beneath the raised floor of a data center. Cooled air exits from conventional CRACs at a very high velocity. However, air velocities are low and constant after the air has traveled away from the CRAC a certain distance. The plenum provides a path for cooled air to travel from the CRAC to the data center. Cooled air is distributed to the equipment in the room by placing supply outlets in the form of floor tiles with perforations in close proximity to the cool air inlet vents of the equipment.
[0010] The plenum of today's building must now house building components and infrastructure beyond HVAC apparatus. By combining a building's HVAC system with its power, voice, and data cabling into the under floor plenum, significant improvements can be realized in terms of increased flexibility and reduced costs associated with reconfiguring building services. Consequently, under-floor systems, including UFAD systems, have become desirable in view of the fact that office buildings today have high office space reconfiguration rates resulting from tenant turnover and from the extensive and ever-changing information technology infrastructure and needs of business.
[0011] When cabling runways, copper and fiber distribution and power feeds for servers share plenum space with pressurized air, plenum airflow distribution becomes less predictable. Because rigid building structural members often define the lateral confines of the plenum, the configuration of a plenum cannot easily change to meet airflow demands. This is particularly a concern when dealing with a data center that was built many years ago, and has not been upgraded to meet current standards. Airflow is generally calculated to provide for sufficient cooling in newly constructed or recently updated data centers. Based upon such airflow calculations and measurements, perforated floor tiles and CRAC blower speeds are adjusted to achieve a desired airflow rate. However, after thermal demands are calculated and cooling parameters set, airflow rates are often unintentionally changed. Airflow rates often decrease due to the addition of cables and other items within the plenum. Modifications, such as holes, in the plenum can also cause drastic changes to the airflow rates by creating a low-resistance bypass for the high-pressure cooling air. Conditions and modifications within the plenum space and imprecise calculations and measurements often produce undesirable airflow distribution through the perforated floor tiles, which could, in turn, harm electronic equipment. There is thus a need in the art for a system that can direct airflow within a plenum and which can be easily installed, modified and removed.
SUMMARY OF THE INVENTION
[0012] The present invention meets the need in the art by providing for plenum partition baffle system that non-destructively mounts to the existing plenum support structures. The system is adjustable in height and width. The system comprises an assembly of interconnectable flexible baffle panels (“baffles”). Each baffle has a first and second surface. In the preferred embodiment at least one surface of the baffle includes a scored grid pattern that divides the baffle into segments. The terms “scored” or “scoring” as used in this patent application are defined to include marks or lines created upon a surface by way of scoring, press-cutting, etching or any other technique that produces surface marks via the incomplete cutting or removal of material. The elemental shape of the scored grid is preferably rectangular, but may be any regular shape including, but not limited to, a polygon, a circle, an ellipse or an oval. The grid pattern may even comprise varying and irregular shapes. The scored segments allow the baffle to be sized and shaped simply by breaking apart or tearing off segments of the baffle along the scored grid lines. The baffle can thus be sized and shaped on-site with or without tools. By virtue of its removably segmented constructed, cable, ductwork and other building infrastructure inside the plenum may be routed through the baffle anywhere in the system and including directly the applicable equipment.
[0013] In the preferred embodiment, each scored rectangle (the elemental shape) contains an additional scored aperture outline generally centered within it and which in the preferred embodiment is racetrack or oval shaped. The areas of the baffle within the scored aperture outlines constitute “pop-out sections.” These pop-out sections may be removed by hand from the baffle by application of pressure applied upon the area of the baffle within the aperture outline. In the preferred embodiment, the pressure necessary to remove the pop-out section is finger pressure. Alternatively, the pop-out section can be pressed out with a tool or can be cut out by drawing a knife-edge or sharp tool along the scored outline. Once the pop-out section is removed, a fastener-accepting aperture results in the baffle. These apertures provide means by which each baffle may be interconnected with another baffle to create a longer or larger array of baffles. The resulting apertures also allow any baffle to be mounted, without tools, to the floor pedestals supporting the raised floor and without destructive attachments to either the floor pedestals or any intra-plenum structures.
[0014] By virtue of its interconnection feature and its non-destructive mounting feature, the baffle system can be easily reconfigured as cooling needs change. Data center in-house personnel can install the system to direct airflow from the CRAC units to areas where it is needed most. The adjustable and flexible nature of the system also allows the system to be installed in plenums that vary widely in dimensions such as in the height of the raised floor above the sub-floor.
[0015] When installed, the system directs airflow from CRAC units to equipment within the data center. The system can also direct airflow away from the workstations, corridor spaces and command control console areas where cooled air is not required or desired. By directing airflow, the system allows data centers to save electricity and costs associated with electricity usage. In some circumstances, installation of the system may lower costs associated with the purchase of one or more CRACs. The present invention provides a system to direct cool airflow under the raised floor to more effectively control the high heat temperature zones within a data center. By increasing efficiency the invention may lower electricity costs. The system may reduce the number of CRAC's required to cool a date center. The system can also be used to partition off areas under workstations, corridor stations and command control console areas where cooled air is not required or desired. The system can also be used to separate hot aisles or air from cold aisles of air. The system provides a solution to airflow distribution problems without major reconstruction of the existing structure and without adding sheet metal ducting within the plenum spaces of data centers. The system is removable and repositionable thereby allowing data center managers increased flexibility in arranging equipment within a data center. The system according to the present invention is constructed of material that is more flexible and easier to work with than sheet metal or ductwork. The cost of labor for installation of the system may also be less expensive than the installation of sheet metal ductwork. It is a feature and advantage of the invention disclosed herein that the baffles can be adapted for use within any plenum, including the plenum of a hung or drop ceiling, and can be mounted to any plenum support structures including but not limited to floor pedestals or ceiling tile framework supports. These and other advantages and features of the present invention will become apparent from the following detailed description in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a plan view of a data center.
[0017] FIG. 2 is a cut-away perspective view of a raised floor arrangement illustrating a typical pedestal supporting floor tiles and further illustrating examples of cable trays and conduits.
[0018] FIG. 3 is a cut-away perspective view of the raised floor arrangement as drawn in FIG. 2 illustrating a preferred embodiment baffle of the present invention installed.
[0019] FIG. 4 is an elevation view of a baffle according to a preferred embodiment of the present invention.
[0020] FIG. 5 is an elevation view of a baffle in which a cable tray opening, another opening and a flexible self-sealing dam have been inserted in areas where segments of the baffle have been removed.
[0021] FIG. 6 is an elevation view of two interconnected baffles.
[0022] FIG. 7 is an overhead section view depicting how two overlapping baffles may be interconnected using a pass-through attachment device such as a screw or rivet.
[0023] FIG. 8 is a perspective view of a baffle attached to a pedestal.
[0024] FIG. 9 is an elevation view of a baffle attached to a pedestal.
[0025] FIG. 10 is a cross section view of a baffle connected to a pedestal in a bypass or straight arrangement.
[0026] FIG. 11 is a cross section view of a baffle connected to a pedestal with a baffle in a corner or curved arrangement.
[0027] FIG. 12 is a perspective view of a baffle with air blades attached to it.
[0028] FIG. 13 is an elevation view of a baffle depicting an alternate embodiment of scored cut features.
[0029] FIG. 14 is an elevation view of an alternate embodiment baffle having accordiated pleats.
[0030] FIG. 15 is an elevation view of an alternate embodiment baffle having accordiated pleats.
[0031] FIG. 16 is a cross section of a baffle drawn in FIG. 15 illustrating an example of the baffle in an extended state.
[0032] FIG. 17 is a cross section of a baffle drawn in FIG. 15 illustrating an example of the baffle in a compacted state.
[0033] FIG. 18 is a perspective view of a hung ceiling and further illustrating an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] The invention is plenum partition baffle system comprised of lightweight and flexible baffles that may be easily installed interconnected and easily installed upon plenum support structures without destruction attachment to the structures. After installation the baffles may be easily removed from each other and also easily removed from the support structures. In the preferred embodiment the baffles are scored to allow for break-apart sizing and shaping. Due to their break-apart construct the baffles may be sized and shaped with or without tools to allow for intra-plenum installation. The break-apart construct also allows for the passage of cables and building infrastructure through them in form-fitting or near form-fitting manner.
[0035] Referring to FIG. 1 , there is shown a data center 1 . Within the data center 1 are CRACs 3 , controlled air zones 5 and equipment racks 59 for servers and other conventional computer and data center equipment. FIG. 2 shows a raised floor 7 of the data center 1 . The raised floor 7 of the data center 1 may have floor tiles 8 that are perforated (not shown) to allow air to flow up through the perforated floor tiles 8 into the data center 1 . Pedestals 9 extend from sub-floor 11 and support the raised floor 7 . Plenum 13 is the space between the raised floor 7 and the sub-floor 11 . In a building having a conventional raised floor, cable raceways 15 and cable trays 17 provide support paths for wires and cables running through the plenum 13 and into the equipment within the data center 1 . FIG. 3 shows an embodiment of the plenum partition baffle system 19 of the present invention in use within the plenum 13 depicted in FIG. 2 .
[0036] In operation, the system 19 directs airflow within the plenum 13 . System 19 is assembled from individual interconnecting baffles 21 . Individual baffles 21 are connected to form an assembly of baffles 20 . In the preferred embodiment, the baffles 21 are rectangular in shape, but can be any other shape. In the preferred embodiment, the baffles 21 are made from a flame retardant polypropylene material, such as FORMEX™ GK40. However, baffles 21 may be manufactured from any fire retardant substance that is flexible enough to allow bending around and contouring around pedestals and other intra-plenum structure without breaking.
[0037] As shown in FIG. 4 , the preferred embodiment of the baffle 21 includes elemental segments 23 scored into at least one of its surfaces. In the preferred embodiment, the elemental segments 23 are rectangular shaped. The rectangular shape is produced by horizontal and vertical scores 25 which allow changing the baffle 21 to be re-sized or re-shaped by removing a desired number of segments 23 in one or more desired locations. Because of the horizontal and vertical scored lines 25 , portions of the baffle 21 may be removed to achieve a more refined system 19 , shape or size without use of a tool simply by breaking apart or tearing away segments of the baffle. Segments of a baffle may be removed so as to provide the baffle 21 with one or more defined openings 31 as is shown in FIG. 5 . The segments 23 allow portions of the baffle 21 to be removed in order to accommodate cable tray openings 29 or other openings 31 . FIG. 5 depicts a baffle with defined openings receiving a cable try 17 and a flexible self-sealing dam 33 to provide raceways for cables 15 or other equipment. The removed portions of the baffle 21 can be patched or repaired by simply adding a baffle 21 or a portion of a baffle 21 to a specific area of the baffle 21 or system 19 .
[0038] In a preferred embodiment, each elemental segment 23 has a generally horizontally oriented racetrack or oval shaped scored outline 27 generally centered within it that defines a potential aperture. The inner portion 28 of the scored oval outline is preferably removed (popped out) manually by application of finger pressure to the portion of the baffle within the scored oval outline. Alternatively, the inner portion of the scored oval outline could be removed by using a common pressing or cutting hand tool. As shown in FIGS. 8-9 , upon removal of the inner portion 28 a generally horizontally oriented racetrack shaped aperture 37 is formed. As shown in the embodiment of FIG. 4 , oval shaped apertures 37 can be arranged in one or more rows whereby adjacent oval shaped aperture outlines are separated by horizontal distance N. In prototype versions of the preferred embodiment baffle system, baffles wherein the distance N between the generally horizontally oriented oval shaped outlines equals one inch were shown to offer overall improved interconnection and pedestal mounting than baffles having a shorter or longer distance N.
[0039] In operation, the system 19 directs airflow within the plenum space 13 of a data center 1 . The system 19 , is made of an assembly of baffles 20 . As shown in FIGS. 6-7 , the individual baffles 21 are connected to form the assembly of baffles 20 . The baffles may be interconnected by overlapping one baffle with another, aligning a fastener-accepting aperture in one baffle with a like aperture of another baffle and inserting a fastener through the aligned apertures. Any type of fasteners, including but not limited to screws, rivets, bolts or threaded posts, can be used to interconnect the baffles. In the depicted embodiment, a rivet 35 that passes through both baffles 21 via the oval shaped aperture 37 connects the baffles 21 . A preferred rivet 35 is manufactured by Micro Plastics® Inc. (part number 401009). Because each baffle can be reduced in size and re-shaped and because baffles can be interconnected in horizontal or vertical arrangement, an assembled baffle panel of any needed width or height can be built.
[0040] FIGS. 8-9 show the preferred embodiment method of attaching the baffles 21 to the pedestal 9 . In the depicted embodiment, baffle 21 is attached to pedestal 9 by means of fastener 39 that loops around the pedestal 9 and through at least two fastener-accepting apertures 37 . A preferred embodiment mounting fastener 39 is a Richco, Inc. cable tie (part number QTE-30XL). As shown in FIG. 3 , pedestals 9 supporting the raised floor 7 also support the assembly of baffles. The baffles 21 may be connected to a pedestal 9 in such a way so as to allow the baffle to bypass the pedestal or bend around the pedestal to form a corner or angle 40 . FIG. 10 is a cross-section view of a baffle mounted to pedestal 9 whereby the baffle connects to the pedestal in a straight or bypass fashion, producing an approximate straight edge 38 . FIG. 11 is a cross section view of a baffle 21 mounted to the pedestal 9 whereby the baffle bends around the pedestal forming a corner or angle 40 . In the preferred embodiment, the fastener 39 connects the baffle 21 nondestructively to the pedestal 9 by means of a fastener passing through the fastener-accepting apertures 37 . It will now be understood that the baffle may be connected or attached to any side or surface of the pedestal 9 . It will also be appreciated that the oval shaped apertures of the preferred embodiment in the baffles provide distinct advantages over round, square or other shape apertures. First, because the oval aperture is in the nature of a horizontally oriented slot, a baffle comprised of oval apertures has a certain degree of “play” or side-to-side movement when connecting a baffle to another baffle or a pedestal. Thus, the oval shape feature of the apertures also allow for less precise measuring and shaping of the baffle as compared to a round or square hole when sizing and shaping the baffles for installation. This shape feature of the aperture also protects each baffle, the baffle system and any supporting structures from any forces acting against them due to thermodynamic expansion and contraction. Additionally, should the need arise to bend a baffle along a line including a fastener-accepting aperture, insertion of a fastener through a round or square aperture could be rendered difficult or even impossible by virtue of the deformation (reduction of the surface area) of the aperture due to the bending. However, with an oval aperture, the baffle can be bent along a line including an aperture without rendering the aperture impassable. Hence, the oval shape feature of the aperture allows for insertion of fasteners under conditions where the baffle is flexed or bent. Additionally, by virtue of the fact that the oval apertures do not have any interior corners that could serve as starting points for cracks or tears in the baffle material, the oval apertures are structurally advantageous over polygonal apertures.
[0041] The system 19 may be used to partition off a specific area in the plenum 13 . It may also be employed to direct airflow to a specific area of the plenum 13 or may direct airflow away from a specific area of the plenum 13 . The system 19 can vary in size depending on the size of the data center 1 or the plenum 13 . Baffles 21 can be added to the system 19 to achieve the desired height or width. The unique assembly of the invention allows the system 19 to be easily removed and moved and reassembled in another location in the plenum or in another plenum altogether to accommodate data center 1 reconfigurations. This unique assembly allows the system 19 to be increased in size or decreased in size as conditions change or airflow needs change.
[0042] Baffles having the grid pattern made up of elemental scored rectangles having generally centered, horizontally oriented scored oval aperture outlines have proven flexibility in intra-plenum installation. However, other patterns may be used as well. FIG. 13 shows another embodiment of a baffle 63 having vertically oriented, elongated scored oval aperture outlines 45 . The area of the baffle within each elongated oval scored feature can be removed in pop-out manner, preferably by the application of finger pressure to the area. Alternatively, the area within the elongated oval feature can be removed by using a tool to press or cut the area out. When this area is removed, vertically oriented slots are formed, which allow for greater up and down positioning of the baffle. The embodiment 63 depicted in FIG. 13 also demonstrates that a baffle can be provided with full-length vertical scored lines 47 in the center of the baffle 63 .
[0043] FIG. 14 depicts another embodiment baffle 67 having horizontally scored lines 65 that result in horizontal strips 49 . The baffles 67 can also be scored vertically 51 in the center of the baffle.
[0044] The system can be adapted to use accordion baffles 69 , such as is depicted in FIGS. 15-17 . As seen in these figures, this baffle embodiment has accordiated pleats 53 that are connected by vertical scored lines 71 . The accordiated pleats 53 may form the entire baffle 69 (not shown) or only part of the baffle 69 as shown in FIG. 15 . In FIG. 15 , baffle 69 also has an un-accordiated portion 73 . FIG. 16 is a cross section view of an accordion baffle 69 illustrating the accordiated pleats 53 in an extended state. FIG. 17 illustrates the accordiated pleats 53 in a compacted state.
[0045] FIG. 12 illustrates an embodiment of the invention whereby air blades 43 are mounted to a baffle. The air blades 43 can be utilized with other embodiments of the invention as well. In a preferred embodiment, the air blades 43 illustrated in FIG. 12 can be connected, attached or located in operative association with or to the baffle 21 and in a preferred embodiment the racetrack or oval shaped apertures 37 are located relative to connection tabs 61 and a rivet 35 may be used to hold the connection tab and blade in place relative to the baffle. The air blades 43 help move the airflow in a vertical direction.
[0046] The plenum partition baffle system disclosed herein can be easily adapted for use in the plenum or air handling space in a hung or drop ceiling. This embodiment is shown in FIG. 18 . In this embodiment, plenum partition baffle system 19 is located in the plenum created by hung ceiling 55 by using framework supports 81 . Fasteners 39 connect the baffles 21 to the framework supports 81 . Framework supports 81 connect framework 75 (and thus hung ceiling 55 ) to building structure 57 . Hung ceiling 55 has ceiling tiles 77 with which may include vents 79 . The ceiling tiles 77 rest in framework 75 (typically arranged in a grid) or other suspended, hung or dropped ceiling support systems.
[0047] While specific embodiments have been shown and described, many variations are possible. The particular shape of the segments and scored lines and markings, scoring depths and aperture outlines including all horizontal and vertical orientations, dimensions and thicknesses may be changed as desired to suit the floor or ceiling plenum with which the invention is used. The material and its configuration and number of segments may vary although a preferred embodiment is shown and described, for example, the segments may be interlocking puzzle-piece-like shapes and the baffles may be non-rectangular. In addition, though the invention is representatively described herein for use in a pressurized plenum, the invention is equally adaptable for use in heating or cooling system in which the conditioned air in the plenum is maintained at a zero or negative pressure with respect to workspace air and the conditioned air is delivered to the workspace by means of active (e.g., powered fan) supply outlets. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the scope of the invention, which is intended to be defined by the following claims and their equivalents, in which all terms are meant in their broadest reasonable sense unless otherwise indicated. | A system for directing airflow within a plenum comprising sizeable, shapeable, and interconnectable baffles that can be nondestructively attached to plenum support structures. The system includes means for removably interconnecting the baffles and also for removably and non-destructively attaching the baffles to plenum support structure without tools. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a power transmission apparatus used for four-wheel drive vehicles, for instance, and more specifically to a power transmission apparatus for transmitting power via viscous resistance of viscous fluid applied to a plurality of resistance plates arranged within a working chamber of the apparatus.
2. Description of the Prior Art
An example of the above-mentioned power transmission apparatus is disclosed as a viscous coupling apparatus in Japanese Published Unexamined (Kokai) Patent Application No. 58-50349. In this viscous coupling apparatus, a plurality of resistance plates are arranged on the casing side and the shaft side, respectively along the axial direction thereof so as to be alternately opposite to each other and extend in the radical direction thereof within a working chamber filled with a viscous fluid (e.g. silicon oil). Therefore, when either of the casing or shaft is rotated, power is transmitted from one to the other via fluid viscous resistance generated by relative rotation between these resistance plates.
In the above-mentioned prior-art power transmission apparatus or viscous coupling apparatus, however, the working chamber is airtightly formed by sealing members disposed between the casing and two accel shafts and further the resistance plates fixed to the shaft side within the working chamber filled with viscous fluid are arranged along splines formed on the outer circumferential surface of an end of each of the two accel shafts. Therefore, it has been impossible to subassemble the apparatus after the viscous fluid is put into the working chamber. In other words, since the viscous fluid is put after the resistance plates have been assemble and further the sealing members have been attached during vehicle assembly process, there exists a problem in that vehicle assembly work is complicated and therefore vehicle assembly reliability is deteriorated.
To overcome the above-mentioned problem, another prior-art viscous coupling apparatus is disclosed in Japanese Published Unexamined (Kokai) Patent Appli. No. 62-165032. In this apparatus, the working chamber is formed by an outer cylindrical member, two side flanges formed integral with the outer cylindrical member on both the sides thereof, and a hub arranged on the inner circumferential side of the side flanges. Further, a plurality of resistance plates are arranged along the axial direction and alternately fixed to the inner circumferential wall of the, outer cylindrical member and the outer circumferential surface of the hub so as to extend in the radical direction within a working chamber filled with viscous fluid. The inner circumference of the hub is linked with an input shaft to which power is applied and further loosely fitted to the side flanges. Sealing members are disposed at the fitting portion between the hub and the side flanges to form an airtight working chamber.
The above-mentioned second prior-art viscous coupling apparatus has such an advantage as to enable the apparatus to be subassembled; however, since a hub is provided along the axial direction, there exists another problem in that the volume or the radical length of the working chamber is reduced and therefore it is difficult to obtain desired performance. To overcome this problem when the axial length of the working chamber is increased, the apparatus is inevitably increased both in size and weight.
In addition, since the inner circumference of the hub must be centered with respect to the apparatus axis and further the outer circumference of the hub must be centered with respect to the outer cylindrical member, there exist other problems in that the manufacturing process and assembly process are difficult.
SUMMARY OF THE INVENTION
With these problems in mind, therefore, it is the primary object of the present invention to provide a power transmission apparatus which is easy to manufacture and assemble and small in size, while enabling subassembly thereof.
To achieve the above-mentioned object, the power transmission apparatus of the present invention comprises: (a) a multistep shaft formed with a first connecting portion at a first end thereof and a multistep shoulder portion steppedly narrowed in diameter toward a second end thereof opposite to the first end; (b) a casing fitted to said shaft from the second end of said multistep shaft and formed with a second connecting portion near the second end of said multistep shaft, a working chamber being formed between said multistep shaft and said casing so as to be filled with viscous fluid; (c) a plurality of first resistance plates engaged with and arranged along an axial direction of said multistep shaft within the working chamber; and (d) a plurality of second resistance plates engaged with and arranged along an axial direction of said casing within the working chamber, said first and second plural resistance plates being alternately arranged so as to intervene between two other resistance plates. The first connecting portion of said multistep shaft is an input portion to which power is applied, and the second connecting portion of said casing is an output portion from which power is transmitted outside.
In the apparatus according to the present invention, since a connecting portion is formed at an input end of the shaft, and a stepped portion steppedly narrowed toward an output end is formed at the output end thereof so that the casing can be fitted from the output side of the shaft to form the working chamber, it is possible to subassemble the apparatus and therefore to facilitate the assembly work.
Further, since a plurality of resistance plates are arranged at the stepped portion of the shaft, it is possible to eliminate the hub required for the prior-art apparatus, thus minimizing the size of the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the power transmission apparatus according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designates corresponding elements and in which:
FIG. 1 is an illustration showing an entire four-wheel drive system to which the power transmission apparatus according to the present invention is applied;
FIG. 2 is a cross-sectional view showing a power transmission apparatus of the present invention, taken along the line I--I in FIG. 3; and
FIG. 3 is a half front view showing the same apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be explained hereinbelow with reference to the attached drawings. FIG. 1 is an illustration showing an entire four-wheel drive system to which the power transmission apparatus according to the present invention is applied. In this drawing an engine 1 and a transmission 3 are arranged along the lateral direction and on the front side of the vehicle. An output (wheel drive power) obtained through the transmission 3 is transmitted to the right and left front wheels 7 via a transfer 5, and further to the right and left rear wheels 15 via a viscous coupling apparatus 9, a propeller shaft 11 and a final drive unit 13.
The viscous coupling apparatus 9 for transmitting power has such a function that a small torque is transmitted from an input shaft to an output shaft when difference in the number of rotation between the two shafts is small, but a large torque is transmitted when the difference is large.
As shown in FIG. 2, the viscous coupling (power transmitting) apparatus 9 comprises a shaft 19 formed with a flange 17 serving as a first connecting portion (to which an input power is applied), a casing 21 rotatably fitted to the outer circumference of the shaft 19, and an airtight working chamber 23 formed between the shaft 19 and the casing 21. This flange portion 17 is fixed to an output shaft of the transfer 5, in practice.
The shaft 19 is formed into multistep or multishoulder shape composed of a first step portion 25, a second step portion 27, a third step portion 29, a fourth step portion 31, a fifth step portion 33, a sixth step portion 35 and a seventh step portion in such a way that the diameters of these step portions are reduced step by step from the flange 17 formed at one (input) end thereof to the other (output) end thereof. On the other hand, the casing 21 is formed with an outer cylindrical portion 41 having a flange portion 39, and an output member 43 is fitted to the open end of the outer cylindrical portion 41 and fixed thereto by welding, for instance. As shown in FIG. 3., the output member 43 is formed with a boss portion 44 having four threaded portions 44a and serving as a second connecting portion (from which an output power is transmitted). This boss portion 44 is connected to the propeller shaft 11 via a flange portion of a universal joint (not shown), in practice. Further, the casing 21 is fitted to the shaft 19 from the output end side, and rotatably supported by the shaft 19 in such a way that an annular projection 45 of the flange portion 39 of the casing 21 is supported by the third step portion 29 of the shaft 19 via a bearing 47 and further the output member 43 is supported by the seventh step portion 37 of the shaft 19 via another bearing 49. Further, a sealing member 51 is provided between the fourth step portion 31 of the shaft 19 and the flange portion 39 of the casing 21 and further another sealing member 53 is provided between the sixth step portion 35 of the shaft 19 and the output member 43, so that a working chamber 23 is airtightly formed so as to be filled with a viscous fluid such as silicon oil.
Within the working chamber 23, a plurality of resistance plates 57 engaged with splines 55 formed in the inner circumferential wall of the outer cylindrical member 41 of the casing 21 and another plurality of resistance plates 61 engaged with splines 59 formed in the outer circumferential surface of the fifth step portion 33 of the shaft 19 are alternately arranged so as to intervene between the two other resistant plates. Further, plural locating spacer rings 63 are disposed between the two resistance plates 57 spline engaged with the casing 21 to maintain a predetermined distance therebetween in such a way as to be separated away from the outer circumference of the resistance plates 61 spline engaged with the shaft 19. The shaft 19 is formed into a hollow shaft formed with an axial through bore 65 in order to reduce the weight thereof.
Further, a sealing member 69 is disposed between the second step portion 27 of the shaft 19 and a flange portion 67 of an annular projection 45 of the casing 21 without preventing the relative rotation between the shaft 19 and the casing 21. The reference numeral 71 denotes a dust cover disposed in contact with a lip portion of the sealing member 69.
The operation of the first embodiment of the apparatus will be described hereinbelow. A power of the engine 1 is transmitted to the front wheels 7 via the transmission 3 and the transfer 5 and, on the other hand, to the rear wheels 15 via the viscous coupling (power transmission) apparatus 9, the propeller shaft 11 and the final drive unit 13.
A rotational power inputted from the transfer 5 to the shaft 19 of the viscous coupling apparatus 9 is transmitted from the resistance plates 61 rotatable integral with the shaft 19 to the resistance plates 57 rotatable integral with the casing 21 via a viscous resistance of fluid filling the working chamber 23, and further transmitted to the propeller shaft 11 connected to the output member 43 via a universal joint.
In the above-mentioned viscous coupling apparatus 9, since the shaft 19 to which power is inputted is formed with the flange portion 17 (an input connecting portion) on one (input) end side thereof and the multistep portions on the other (output) side thereof in such a way that diameters of the shaft 19 decrease in step fashion, it is possible to fit the casing 21 to the shaft 19 from the other end (output) side thereof during assembly process. In addition, since the working chamber 23 filled with viscous fluid is formed between a step portion (the fifth step portion 33 in this embodiment) and the casing 21, and further plural resistance plates 57 engaged with the splines 55 formed in the inner circumferential wall of the casing 21 and plural resistance plates 61 engaged with the splines 59 formed in the outer circumferential surface of the fifth step portion 33 of the shaft 19 are alternately arranged one by one, it is unnecessary to provide a hub member on the shaft side as in the prior-art apparatus. Therefore, the viscous coupling apparatus can be subassembled as a unit, so that it is possible to simplify the assembly work of the apparatus to a vehicle body as shown in FIG. 1.
In addition, since no hub is provided on the shaft side in the viscous coupling apparatus 9 of the present invention, the volume or the radial length of the working chamber 23 is not reduced. Therefore, it is possible to increase the volume of the working chamber 23 without increasing the axial length thereof or to reduce the size of the apparatus.
An apparent from the above description in the apparatus according to the present invention, since there are provided a shaft having a first connecting portion on one (input) end side and a multistep portions on the other (output) end side, a working chamber formed between the shaft and the casing fitted to the shaft from the other (output) end side and filled with viscous fluid, and two sets of plural resistance plates alternately spline engaged with the casing and the shaft within the working chamber, it is possible to subassemble the apparatus in the state where the working chamber is filled with viscous fluid, thus facilitating the vehicle assembly work. In addition, since the plural resistance plates are directly engaged with a certain step portion of the shaft, it is possible to eliminate the use of the conventional hub and therefore to reduce the volume or the size of the apparatus. | To facilitate subassembly of a power transmitting (viscous coupling) apparatus without use of a hub, the apparatus comprises a multistep shaft formed with an input portion and a multistep shoulder portion steppedly narrowed in diameter from the input portion to the opposite side; a casing fitted to the multistep shaft from the opposite side of the shaft and formed with an output portion; and two sets of resistance plates engaged with and arranged along the axial direction of each of the multistep shaft and the casing, within a working chamber formed between the shaft and the casing, so as to intervene between two other resistance plates. | 5 |
This is a continuation of application Ser. No. 09/542,655 filed Apr. 4, 2000, now U.S. Pat. 6,186,516 which is a continuation of application Ser. No. 08/907,320 filed Aug. 6, 1997, now U.S. Pat. 6,045,141.
BACKGROUND OF THE INVENTION
The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools used with such drivers, the tools may also comprise screwdrivers, nut drivers, burrs, mounted grinding stones and other cutting or abrading tools. Since the tools may have shanks of varying diameter or the cross-section of the tool shank may be polygonal, the device is usually provided with a chuck which is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore.
A wide variety of chucks have been developed in the art. In one form of chuck, three jaws spaced circumferentially, approximately 120 degrees apart from each other, are constrained by angularly disposed passageways in a body attached onto the drive shaft and configured so that rotation of the body in one direction relative to a constrained nut engaging the jaws forces the jaws into gripping relationship with respect to the shank of a tool, while rotation in the opposite direction releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. One example of such a chuck is disclosed in U.S. Pat. Nos. 5,125,673 entitled “Non-Impact Keyless Chuck” and U.S. Pat. No. 5,501,473 entitled “Chuck”, both commonly assigned to the present assignee, and whose entire disclosure is incorporated by reference herein.
While many currently existing chuck designs have been successful, varying configurations are desirable for a variety of applications. Particularly, it would be desirable to have a chuck that could be manufactured with adequate performance for a lower cost than many currently existing chuck designs. For example, typically, the main body of a chuck of the type described in the above-referenced patents is manufactured from metal bar stock. Therefore, the greatest diameter of the chuck body at any point determines the diameter of the bar stock necessary to construct such body. Since bar stock is an expensive component of the chuck, design efforts have been made to minimize the diameter necessary to construct the chuck body which has typically necessitated use of separate thrust washers to receive the axial rearward thrust of the nut as well as separate rear sleeve members attached to the rearward section of the main body in chucks utilizing both front and rear sleeves. In addition, it is necessary to utilize secondary operations to place the oblique jaw passageways in the body and to create the main tool receiving bore. The most common way of forming these passageways and bores is through a drilling operation which necessitates the utilization of primarily round passageways and bores.
SUMMARY OF THE INVENTION
The present invention recognizes and addresses the foregoing considerations, and others of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved chuck.
It is another object of the present invention to provide a chuck that can be manufactured and assembled in a cost effective manner.
It is another object of the present invention to provide a keyless chuck that has a minimum number of individual components that must be assembled.
It is another object of some embodiments of the present invention to provide a chuck that minimizes or eliminates the constraints necessitated by use of bar stock for the main body.
It is another object of the present invention to provide an improved chuck whose main body can be molded.
It is a further object of certain embodiments of the present invention to provide an improved chuck that can be manufactured with a minimum number of operational steps.
These and other objects are achieved by providing a chuck for use with a manual or powered driver having a rotatable drive shaft, the chuck including an integrally molded body member with a nose section and a tail section, the nose section having an axial bore formed therein, and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. A plurality of jaws are slidably positioned in the angularly disposed passageways. Each jaw has a jaw face formed on one side and threads formed on an opposite surface. A nut is rotatably mounted on the body member in engagement with the threads on the jaws, and a sleeve member is provided in driving engagement with the nut whereby when the sleeve is rotated with respect to the body, the jaws will be moved thereby.
These and other objects are further accomplished by providing a chuck for use with a hand or powered driver having a rotatable drive shaft, the chuck including an integrally molded body member having a nose section and a tail section. The nose section has an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. The nose section has a reinforcing member co-molded therewith about at least a portion of its outer circumference. A plurality of jaws are provided slidably positioned in the angularly disposed passageways, each of the jaws having a tool engaging face formed on one side thereof and threads formed on an opposite outer surface. A nut is provided mounted on the body member in engagement with threads on the jaws, and a sleeve member is provided in driving engagement with the nut whereby when the sleeve is rotated with respect to the body, the jaws will be moved thereby.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
FIG. 1A is a longitudinal view, partly in section, of a chuck in accordance with an embodiment of the present invention;
FIG. 1B is an exploded view of the chuck illustrated in FIG. 1;
FIG. 2A is a longitudinal view, partly in section, of a chuck in accordance with another embodiment of the present invention;
FIG. 2B is an exploded view of the chuck of the embodiment of FIG. 2A;
FIG. 3A is a longitudinal view, partly in section, of a chuck in accordance with another embodiment of the present invention;
FIG. 3B is an exploded view of the chuck of the chuck of the embodiment illustrated in FIG. 3A;
FIG. 4 is a longitudinal view, partly in section, of a chuck in accordance with another embodiment of the present invention;
FIG. 5 is a perspective view of a jaw in accordance with an embodiment of the present invention;
FIG. 6 is a perspective view of a chuck in accordance with another embodiment of the present invention;
FIG. 7 is a rear view of the chuck of the embodiment of FIG. 6; and
FIG. 8 is a front view of the chuck of the embodiment of FIG. 6 .
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary construction.
Referring to FIGS. 1A and 1B, a chuck in accordance with an embodiment of the present invention is illustrated. Chuck 10 includes a front sleeve member 12 , a body member 16 and jaws 18 . Body member 16 has a generally cylindrical nose or forward section 20 and a rear or tail section 22 that will be described in more detail below. An axial bore 24 is formed in nose section 20 of body member 16 . Axial bore 24 is somewhat larger than the largest tool shank that the chuck is designed to accommodate. A bore 26 is formed in tail section 22 of body member 16 and may be formed with integral threads or may be affixed to a threaded insert member 27 , either of which is adapted to mate with the drive shaft of a powered or hand driver (not shown). In addition to a bore 26 , a threaded bore, or threaded insert 27 , it should be appreciated that such bore configuration could be replaced with a tapered bore to mate with a tapered drive shaft or otherwise configured in any suitable manner to mate with the drive shaft of a powered or hand driver.
Passageways 30 are formed in body member 16 to accommodate each jaw 18 . In a preferred embodiment, three jaws 18 are employed, and each jaw 18 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 30 and the jaws 18 are angled with respect to the chuck axis but intersect the chuck axis at a common point. Each jaw 18 has a tool engaging face or edge 32 which is generally parallel to the axis of the chuck body 16 , and threads 34 on its opposite and outer surface. Threads 34 of any suitable type and pitch may be utilized within the scope of the present invention as would be readily apparent to one skilled in the art.
Body member 16 includes an integral enlarged diameter portion 36 at its tail section which includes a gripping surface 38 about its outer circumference to allow body member 16 to be held stationary by virtue of the operator grasping this gripping surface. In one preferred embodiment, enlarged diameter portion 36 presents an outer surface of approximately the same diameter as the front sleeve 12 . In one preferred embodiment, passageways 30 and bore 24 are integrally molded into chuck body 16 . In other embodiments, the enlarged diameter surface could present a multi-lobal outer circumference, as illustrated in the embodiment of FIGS. 6-8, or a continuous outer circumference.
Integral enlarged diameter portion 36 forms a ledge 40 for transmitting rearward axial thrust to the body that is generated when tightening the chuck. A thrust ring member 42 is received about body member 16 as illustrated in FIG. 1 A and rests on ledge 40 . Thrust ring member 42 forms a bearing race which supports bearings as will be described in more detail below.
The present invention further includes a nut 44 which, in a preferred embodiment, is a unitary nut and includes threads 46 for mating with threads 34 on jaws 18 whereby when said nut is rotated with respect to said body, the jaws will be advanced or retracted. In a preferred embodiment, nut 44 includes a knurled or ridged surface 48 to enhance the interconnection between the nut and a front sleeve received thereover.
A bearing assembly 50 is adapted to be placed between thrust ring member 42 and nut 44 . Bearing assembly 50 includes bearing members 52 which, in a preferred embodiment, may be ball bearings or roller bearings and a cage 54 . Cage 54 includes a lip 56 extending perpendicular to the primary cage portion 58 . Bearing assembly 50 with lip 56 is configured so that lip 56 is received about the outer circumference of thrust ring member 42 when in place to maintain bearing assembly 50 in its proper location.
Front sleeve member 12 is adapted to be press fitted onto nut 44 and extends over at least a portion of nose section 20 of body member 16 . A reinforcing member 60 is received over the forwardmost portion of body member 16 and serves as both a nosepiece to protect the forwardmost portion of the body and a reinforcing member to strengthen body member 16 in the nose section. Reinforcing member 60 includes a first circumferential leg 62 which extends substantially the distance between the forwardmost portion of body member 16 to the location where the jaw holes open through the outer circumference of the nose section 20 . This reinforcing leg serves to provide additional support to the body in the area between the jaw passageways and the forwardmost section of the body member 16 . Reinforcing member 60 also includes a second circumferential leg 64 which extends toward nut 44 into a position to prevent nut 44 from disengaging threads 34 by excessive movement in the direction of the forwardmost portion of the nose section. Reinforcing member 60 also includes a ledge 66 extending circumferentially around reinforcing member 60 and configured to engage ledge 68 of sleeve 12 should sleeve 12 become disengaged from nut 44 . The relationship between ledges 66 and 68 is such that sleeve 12 cannot move over reinforcing member 60 , which arrangement provides a secondary retaining mechanism for sleeve 12 . In a preferred embodiment, reinforcing member 60 is press fitted over the nose section of body member 16 and provides additional hoop strength in that location, but it should be appreciated that it could be affixed in any suitable way. In addition to the above, reinforcing member is exposed when chuck 10 is assembled and may preferably be constructed from low carbon steel and coated or plated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. In a preferred embodiment, such coating may be zinc or nickel, however, it should be appreciated that any suitable coating could be utilized, and any suitable material or process could be utilized to produce the reinforcing member.
While an integral enlarged diameter portion 36 is illustrated with the rear or tail section of the chuck of the embodiment of FIGS. 1A and 1B, it should be appreciated that this section could be of reduced diameter and sleeve 12 extended to the rearmost portion of the chuck. This alternative would be feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws.
The circumferential surface of front sleeve member 12 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. As stated above, the outer surface of the integral enlarged diameter portion 36 may be likewise configured. The front sleeve may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass-filled polypropylene, or a blend of structural plastics. Other composite materials such as, for example, graphite filled polymerics would also be suitable in certain environments. As would be appreciated by one skilled in the art, the materials from which the sleeve of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.
It will be appreciated that the integral enlarged diameter portion 36 is a part of body member 16 while front sleeve member 12 is operatively associated with nut 44 and secured with respect to body member 16 to allow for relative rotation therewith. Relative movement of the front sleeve 12 and integral enlarged diameter portion 36 , due to the interaction between threads 34 on jaws 18 and threads 46 on nut 44 , causes jaws 18 to be advanced or retracted depending on the direction of relative movement.
An important aspect of the present invention is that body member 16 is an integrally molded unit which can, depending on the desired configuration, include integrally molding the enlarged diameter portion, the passageways 30 , and bore 24 . Such molding of one or more of these components eliminates problems associated with minimizing bar stock diameters as well as the necessity of further processing steps such as drilling passageways and bores for receipt of the tool and jaws. It should be appreciated, however, that it is within the scope of the present invention to mold body member 16 without certain components discussed above and to use further processing steps to complete the chuck body such as, for example, drilling jaw passageways.
In a preferred embodiment, the body member 16 may be formed from a structural plastic, such as polycarbonate, a filled polypropylene, for example, glass-filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite-filled polymerics would also be suitable in certain environments. At least regarding use of a plastic material, injection molding would appear to be the preferred method. In addition, the chuck body 16 could be molded from a suitable metal, or other process or material such as zinc die casted.
It should be appreciated that molding body member 16 , as opposed to utilizing various machining operations requiring the drilling of passageways and bores, would allow bore 24 as well as passageways 30 to have non-circular cross-sectional configurations. This would allow, for example, jaws to be manufactured with non-circular configurations including cross-sectional configurations that are rectangular, triangular, trapezoidal or any other suitable configuration.
It should be appreciated that while a one-piece nut is illustrated with a press-fitted sleeve, any known configuration of nut and/or sleeve relationships could be utilized such as, for example, a two-piece nut and/or a drive lug engaging relationship between sleeve member 12 and nut 44 . Examples of such other arrangements are illustrated in the patents referenced above and incorporated herein in their entirety.
Referring to FIGS. 2A and 2B, a chuck 110 in accordance with another embodiment of the present invention is illustrated. Chuck 110 includes a front sleeve member 112 , a body member 116 , and jaws 118 . Body member 116 has a generally cylindrical nose or forward section 120 and a rear or tail section 122 that will be described in more detail below. An axial bore 124 is formed in nose section 120 of body member 116 . Axial bore 124 is somewhat larger than the largest tool shank that the chuck is designed to accommodate. A bore 126 is formed in tail section 122 of body member 116 and may be formed with integral threads or may be affixed to a threaded insert member 127 , either of which is adapted to mate with the drive shaft of a powered or hand driver (not shown). A portion of the outer circumference of insert member 127 may be knurled as illustrated at 128 or otherwise configured to provide a secure engagement with tail section 122 of body member 116 . For example, it could be co-molded with the body or pressed therein. Insert 127 could be constructed of any suitable material including brass or other metal and may include a socket 129 for receipt of a mounting tool to drive the chuck onto the tool spindle for mounting the chuck in a manner set forth in commonly assigned U.S. Pat. No. 5,193,824, the disclosure of which is incorporated by reference herein in its entirety.
In addition to a bore 126 or threaded insert 127 , it should be appreciated that such bore could be replaced with a tapered bore to mate with a tapered drive shaft or otherwise configured in any suitable manner to mate with the drive shaft of a powered or hand driver. Other configurations could also be suitable, such as a smooth bore to mate with a knurled or barbed spindle from the power driver. Further it is possible that the spindle of the powered or hand driver could be co-molded directly with the body member 116 . It should also be appreciated that part or all of the internal configuration of bore 24 , 124 , 224 , 324 could be non-circular, such as hexagonally shaped, for receipt of a tool therein for mounting of the chuck on a threaded drill spindle as described in more detail below.
Passageways 130 are formed in body member 116 to accommodate each jaw 118 . In a preferred embodiment, three jaws 118 are employed, and each jaw 118 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 130 and the jaws 118 are angled with respect to the chuck axis but intersect the chuck axis at a common point. Each jaw 118 has a tool engaging face or edge 132 which is generally parallel to the axis of the chuck body 116 , and threads 134 on its opposite and outer surface. Threads 134 of any suitable type and pitch may be utilized within the scope of the present invention as will be readily apparent to one skilled in the art.
Body member 116 includes an integral enlarged diameter portion 136 at its tail section which includes a gripping surface 138 about its outer circumference to allow body member 116 to be held stationary by virtue of an operator grasping this gripping surface. In one preferred embodiment, passageways 130 and bore 124 are integrally molded into chuck body 116 .
Integral enlarged diameter portion 136 forms a ledge 140 for transmitting rearward axial thrust generated when tightening the chuck to the body.
The present invention further includes a nut 144 which, in a preferred embodiment, is a unitary nut and includes threads 146 for mating with threads 134 on jaws 118 whereby when said nut is rotated with respect to said body, the jaws will be advanced or retracted. In a preferred embodiment, nut 144 is co-molded with front sleeve 112 as will be described in more detail below.
Front sleeve member 112 is co-molded with nut 144 and extends over at least a portion of nose section 120 of body member 116 . A reinforcing member 150 is co-molded about the outer circumference of at least a portion of forward section 120 of body member 116 to provide additional strength to that portion of body member 116 . While co-molding is described, a press fit or other configuration could be utilized.
An extended nosepiece 152 is received over the forwardmost portion of body member 116 and serves as both a nosepiece and a retaining member. Extended nosepiece 152 includes a nut engagement portion 154 that is adapted to maintain nut 144 in place during operation of the chuck. Since sleeve 112 and nut 144 are co-molded together, extended nosepiece 152 also maintains sleeve 112 in place through its engagement with nut 144 . Extended nosepiece 152 is configured and adapted to extend to a point near where passageways 130 intersect axial bore 124 . Nut engagement portion 154 is dimensioned and configured to prevent nut 144 from disengaging threads 134 by excessive movement in the direction of the forwardmost portion of the nose section. In addition to the above, extended nosepiece 152 is exposed when chuck 110 is assembled and may preferably be a metallic member such as steel and may be coated or plated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. In a preferred embodiment, such coating may be zinc or nickel, however, it should be appreciated that any suitable coating could be utilized.
While an integral enlarged diameter portion 136 is illustrated with the rear or tail section of the chuck of the embodiment of FIGS. 2A and 2B, it should be appreciated that this section could be reduced in diameter and the sleeve 112 extended to the rearmost portion of the chuck. This alternative would be feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws.
The circumferential surface of front sleeve member 112 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. As stated above, the outer surface of the integral enlarged diameter portion 136 may likewise be configured. The front sleeve may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass-filled polypropylene, or a blend of structural plastics. Other composite materials such as, for example, graphite-filled polymerics would also be suitable in certain environments. As would be appreciated by one skilled in the art, the materials from which the sleeve of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.
It will be appreciated that the integral enlarged diameter portion 136 is a part of body member 116 , while front sleeve member 112 is operatively associated with nut 144 and secured with respect to body member 116 to allow for relative rotation therewith. Relative movement of the front sleeve 112 and integral enlarged diameter portion 136 , due to the interaction between threads 134 on jaws 118 and threads 146 on nut 144 , causes jaws 118 to be advanced or retracted dependent on the direction of relative movement.
An important aspect of the present invention is that body member 116 is an integral molded unit which can, depending on the desired configuration, include integrally molding the expanded circumferential portion, the passageways 130 and bore 120 . Such molding of one or more of these components eliminates problems associated with minimizing bar stock diameters as well as further processing steps of drilling passageways and bores for receipt of the tool and jaws. It should be appreciated, however, that it is within the scope of the present invention to mold body member 116 without certain components discussed above and to use further processing steps to complete the chuck body such as, for example, drilling jaw passageways.
In a preferred embodiment, the body member 116 may be formed from a structural plastic, such as polycarbonate, a filled polypropylene, for example, glass-filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite-filled polymerics, would also be suitable in certain environments. In addition, the chuck could be molded from a suitable metal or other process or material such as zinc die casted.
It should be appreciated that molding body member 116 as opposed to utilizing various machining operations requiring the drilling of passageways and bores, would allow bore 124 as well as passageways 130 to have non-circular cross-sectional configurations. This would allow, for example, jaws to be manufactured with non-circular configurations, including cross-sectional configurations that are rectangular, triangular, trapezoidal or any other suitable configuration. Jaws of a rectangular cross-sectional configuration are illustrated at 118 in FIG. 2 B. Jaws 118 could be constructed in any known manner, but a presently preferred manner is utilization of powder metal.
It should be appreciated that while a one-piece co-molded nut/sleeve arrangement is illustrated, any known configuration of nut and/or sleeve relationships could be utilized as set forth above.
Referring to FIGS. 3A and 3B, a chuck 210 in accordance with another embodiment of the present invention is illustrated. Chuck 210 includes a front sleeve member 212 , a body member 216 , and jaws 218 . Body member 216 has a generally cylindrical nose or forward section 220 and a rear or tail section 222 that will be described in more detail below. An axial bore 224 is formed in nose section 220 of body member 216 . Axial bore 224 is somewhat larger than the largest tool shank that the chuck is designed to accommodate. A bore 226 is formed in tail section 222 of body member 216 and may be formed with integral threads or may be affixed to a threaded insert member 227 , either of which is adapted to mate with the drive shaft of a powered or hand driver (not shown). A portion 228 of the outer circumference of insert member 227 may be knurled or otherwise configured to provide a secure engagement with tail section 222 of body member 216 . Insert 227 may include a mounting socket as set forth above for engagement with a rotatable tool for attaching the chuck to the spindle of a powered driver. While a bore 226 or threaded insert 227 are illustrated, it should be appreciated that such bore could be replaced with a tapered bore to mate with a tapered drive shaft or otherwise configured in any suitable manner to mate with the drive shaft of a powered or hand driver.
Passageways 230 are formed in body member 216 to accommodate each jaw 218 . In a preferred embodiment, three jaws 218 are employed, and each jaw 218 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 230 and the jaws 218 are angled with respect to the chuck axis but intersect the chuck axis at a common point. Each jaw 218 has a tool engaging face 232 which is generally parallel to the axis of the chuck body 216 , and threads 234 on its opposite and outer surface. Threads 234 of any suitable type and pitch may be utilized within the scope of the present invention as will be readily apparent to one skilled in the art.
Body member 216 includes an integral enlarged diameter portion 236 at its tail section which includes a gripping surface 238 about its outer circumference to allow body member 216 to be held stationary by virtue of an operator grasping this gripping surface. In one preferred embodiment, passageways 230 and bore 224 are integrally molded into chuck body 216 . Integral enlarged diameter portion 236 forms a ledge 240 for transmitting rearward axial thrust generated when tightening the chuck to the body 216 .
The present invention further includes a nut 244 which, in a preferred embodiment, is a unitary nut and includes threads 246 for mating with threads 234 on jaws 218 whereby when said nut is rotated with respect to said body, the jaws will be advanced or retracted. In a preferred embodiment, nut 244 includes drive lug receiving portions 247 for receiving drive lugs from front sleeve member 212 for rotational engagement as will be described in more detail below.
Front sleeve member 212 extends over at least a portion of nose section 220 of body member 216 and includes drive lugs 248 which are received in drive lug receiving portions 247 so that front sleeve 212 is rotationally coupled with nut 244 .
An extended nosepiece 252 is received over the forwardmost portion of body member 216 and serves to protect the forwardmost portion of body member 216 as well as reinforce the forward portion of body member 216 . Extended nosepiece 252 extends from the forwardmost portion of the nose section to a position near the intersection of passageways 230 with bore 226 . In addition to its protecting and reinforcing functions, extended nosepiece 252 also engages a portion of front sleeve 212 to maintain front sleeve 212 in rotational engagement with nut 244 .
In addition, since extended nosepiece 252 is exposed when chuck 210 is assembled, it may be made of any suitable material and, if metal, such as stamped from a low carbon steel, may preferably be coated with a non-ferrous metallic coating to prevent rust and to enhance its appearance. In a preferred embodiment, such coating may be zinc or nickel, however, it should appreciated that any suitable coating could be utilized.
While an integral enlarged diameter portion 236 is illustrated with the rear or tail section of the chuck of the embodiment of FIGS. 3A and 3B, it should be appreciated that this section could be reduced in diameter, and the sleeve 212 extended to the rearmost portion of the chuck. This alternative would be feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws.
The circumferential surface of front sleeve member 212 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. As stated above, the outer surface of the integral enlarged diameter portion 236 may likewise be configured. The front sleeve may be fabricated from a structural plastic such as a polycarbonate, a filled polypropylene, for example, glass filled polypropylene, or a blend of structural plastics. Other composite materials such as, for example, graphite-filled polymerics would also be suitable in certain environments. As would be appreciated by one skilled in the art, the materials from which the sleeve of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.
It will be appreciated that the integral enlarged diameter portion 236 is a part of body member 216 , while front sleeve member 212 is operatively associated with nut 244 and secured with respect to body member 216 to allow for relative rotation therewith. Relative movement of front sleeve 212 and integral enlarged diameter portion 236 , due to the interaction between threads 234 on jaws 218 and threads 246 on nut 244 , causes jaws 218 to be advanced or retracted dependent on the direction of relative movement.
An important aspect of the present invention is that body member 216 is an integral molded unit which can, depending on the desired configuration, include integrally molding the expanded circumferential portion, the passageways 230 and bore 220 . Such molding of one or more of these components eliminates problems associated with minimizing bar stock diameters as well as further processing steps of drilling passageways in bores for receipt of the tool and jaws. It should be appreciated, however, that it is within the scope of the present invention to mold body member 216 without certain components discussed above and to use further processing steps to complete the chuck body as, for example, drilling jaw passageways.
In a preferred embodiment, the body member 216 may be formed from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass-filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite-filled polymerics, would also be suitable in some environments. In addition, the chuck could be molded from a suitable metal or other process or material such as zinc die casted.
It should be appreciated that molding body member 216 , as opposed to utilizing various machining operations requiring the drilling of passageways and bores, would allow bore 224 as well as passageways 230 to have non-circular cross-sectional configurations. This would allow, for example, jaws to be manufactured with non-circular configurations including cross-sectional configurations that are rectangular, triangular, trapezoidal or any other suitable configuration. FIGS. 3B and 5 best illustrate the jaws with rectangular cross-sectional configuration. Jaws in accordance with the present embodiments may be constructed of any suitable material or process. It should be appreciated that while a one-piece nut with drive member arrangement is illustrated, any known configuration of nut and/or sleeve relationships could be utilized as set forth above.
Referring to FIG. 4, a chuck in accordance with another embodiment of the present invention is illustrated. The embodiment of FIG. 4 is the same as that of FIGS. 3A and 3B except nosepiece 252 of FIGS. 3A and 3B is replaced with a sleeve retention band 300 . Sleeve retention band 300 retains the front sleeve in place but allows the forward portion of the chuck body member to be exposed. Sleeve 300 is pressed or otherwise retained on body 220 . While a retaining band 300 is illustrated, any type of retaining member could be utilized to replace nosepiece 252 or band 300 .
Referring to FIGS. 6-8, another embodiment of the present invention is illustrated, The operational mechanism of the embodiment of FIGS. 6-8 is the same as that of the embodiment of FIGS. 3A and 3B. Front sleeve 312 is rotatable with respect to the integral enlarged diameter portion 336 . Integral enlarged diameter portion 336 is integral with the remainder of the chuck body which is as set forth with respect to FIGS. 3A and 3B. Sleeve 312 is retained in place by nosepiece 352 , and sleeve 312 is operatively connected to a nut and jaws as set forth in FIGS. 3A and 3B.
In the embodiment of FIGS. 6-8, integral enlarged diameter portion 336 is of a multi-lobal configuration that provides a unique ornamental configuration as well as a unique gripping surface. Three lobes, 350 , 351 , 352 , are illustrated with concave surfaces 355 interconnecting the lobes. A sloping surface 360 also interconnects the lobes 350 , 351 , 352 . Each lobe has a jaw guideway 365 molded therein, and a threaded insert 370 is received in the center portion for mounting to a spindle. The internal bore of the nose section of the body member is formed with a non-circular configuration 375 for receipt of a tool therein for threadedly mounting the chuck on a spindle. This non-circular configuration could be for the entire length of the bore or a portion thereof. While a tri-lobal configuration is illustrated, it should be appreciated that any number of lobes would be within the scope of the present invention.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. For example, the multi-lobal configuration of FIGS. 6-8 could be utilized with any embodiment either as an integral portion or a separate sleeve. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention so further described in such appended claims. | A chuck includes an integrally molded body member having a nose section and tail section. A plurality of jaws are slidably positioned in angularly disposed passageways in the nose section. A nut is rotatably mounted on the body and is in engagement with threads on the jaws. A reinforcing member is co-molded with the nose section about at least a portion of the outer circumference of the nose section. The tail section extends radially outward to form a gripping surface and axially forward to form a thrust bearing surface in operative engagement with the nut so that the nut transfers rearward axial force to the thrust bearing surface. | 1 |
This application is a national stage of PCT/US99/06365 filed Mar. 24, 1999 and claims benefit of Provisional Application No. 60/079,152 and 60/101,630 filed Mar. 24, 1998 and Sep. 24, 1998 respectively.
FIELD OF THE INVENTION
The present invention relates to high-pressure integral tube coupling arrangements. More particularly, the present invention relates to such arrangements for coupling flexible hoses, such as a reinforced rubber hoses to metal tubes for use in systems such as vehicle brake and clutch systems.
BACKGROUND OF THE INVENTION
In discussing the automotive industry, the Background of U.S. Pat. No. 5,037,142 states: “a wide variety of connector devices have been utilized to connect tubes to hoses for conducting fluid therethrough or transmitting a hydraulic force through a column of oil contained therein. In many cases, specialized couplings are required which not only hydraulically connect adjacent tubes or pipes, hoses and other conduits in a fluid-tight manner, but also provide effective support while allowing relative movement of components and providing protection in relatively harsh environments.”
Current methods for joining hoses to metal tubes still substantially rely on threaded couplings in which an externally threaded hollow nut is threaded into a internally threaded fitting to hold a flared tube tightly within the fitting. Since both the nut and the fitting must be machined, they are relatively expensive. In addition, making the connection is time consuming and labor intensive because it is not conveniently adaptable to automation. Moreover, quality control is difficult because there is the possibility of threaded components being joined without proper alignment so that threads are stripped, resulting in joints that leak and are subject to failure when operated at high pressures over long time periods of time in adverse environments. In view of these difficulties, there have been attempts to form couplings which do not require threaded components. Brazing a tube onto a hose fitting is one approach. Since these couplings are frequently exposed when used with brake systems, clutches and hoses, they are subject to environmental degradation because of moisture, road salt, wide temperature fluctuations and mechanical impacts and vibrations, all of which combine to accelerate corrosion. In order to protect brazed joints from corrosion, it is necessary to plate the assemblies which is in and of itself a relatively expensive undertaking. Moreover, these assemblies frequently require parts which have multiple elements each of which has the potential to provide a leak path and each of which must be handled and stored.
The technology of coupling hoses and tubes is now generally going to “quick-connect” type couplings in which all that is required to achieve a fluid tight connection is for two components being joined to be axially pushed toward one another, so that there is no need to rotate components of a coupling, one with respect to the other. When coupling metal tubes to rubber hoses, it is the practice to crimp the rubber hose within the coupling which is a rapid, reliable process requiring only a single metal-deforming step once the hose is inserted into the coupling. In order to further simplify assembly so as to reduce cost, it is desirable to simplify connecting the tube to a crimpable fitting.
SUMMARY OF THE INVENTION
In view of the aforementioned considerations, it is a feature of the present invention to provide new and improved tube-to-hose couplings which are reliable, inexpensive and yet require manufacturing steps which are minimal and do not introduce difficulties of their own.
In view of this feature and other features, the present invention is directed to a coupling arrangement for connecting a tube to a hose wherein the tube has a main portion and an insertion portion, the insertion portion being inserted through the fitting into the hose. The tube further has at least a first outwardly extending radial projection which cooperates with the fitting, the insertion portion of the tube extending beyond the radial projection to the terminus of the tube. The fitting has a first portion with a bore for receiving the tube therethrough and a second portion extending axially from the first portion for receiving the hose therein, with an interior surface on the first portion facing the second portion. The tube is disposed in the bore of the fitting with the outwardly extending projection abutting the interior surface on the first portion and the insertion portion extending into the second portion of the tube for insertion into the hose.
In a further aspect, the fitting includes a second abutment surface thereon facing away from the second portion for opposing axial movement of the tube toward the second portion of the fitting, and in a still further aspect, the portion of the tube engaged by the second abutment surface is on the first projection.
In a further aspect, the second abutment surface is on a portion of the fitting which is radially and axially deformed into abutment with the second abutment surface.
In still a further aspect, the second axially extending abutment is at a radially extending end of the fitting.
In a further aspect, the second portion of the fitting is a crimping collar for radially engaging the hose while the insertion portion of the tube is within the hose.
In still a further aspect of the invention, the main portion of the tube is covered with a layer of deformable protective material with the insertion portion and radially extending radial protection being uncoated. In accordance with this aspect of the invention, there is a metal-to-metal seal between the fitting and the uncoated radial projection. On the other hand, the definable protective material may be pressed into the fitting to provide a sealing area.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a perspective view of a prior art arrangement for joining a metal tube to a flexible hose;
FIG. 2 is a side view, mostly in elevation, showing a first embodiment of a prior art threaded coupling used to join a tube to a hose;
FIG. 3 is a side view, mostly in elevation, showing a second embodiment of a prior art threaded coupling used to join a metal tube to a hose;
FIG. 4 is a side elevation of a prior art brazed joint used to couple a metal tube to a flexible hose;
FIG. 5 is a side view, mostly in elevation, showing a first embodiment of a coupling in accordance with the present invention utilized to couple metal tube to a flexible hose;
FIGS. 6A-6D are side views, mostly in elevation, illustrating the fabrication and assembly of the coupling of FIG. 5;
FIG. 7 is a side elevation showing the tube of the present invention, but for clarity illustrated without the fitting;
FIG. 8 is a side elevation of a fitting shown in FIGS. 5, 6 B and 6 D showing an embodiment of the fitting with pockets for receiving beads formed on the tube;
FIG. 9 is a side elevation of a second embodiment of the fitting of FIGS. 5, 6 B and 6 D having no pockets for receiving beads on the tube;
FIG. 10 is a side elevation showing a third embodiment of the invention;
FIG. 11 is a side elevation of a fourth embodiment of the invention; and
FIGS. 12A-D are side elevation views showing a preferred assembly technique for embodiment of the invention illustrated in FIG. 11 .
DETAILED DESCRIPTION
Prior Art Arrangements: FIGS. 1 - 4
Referring now to FIG. 1, there is shown a prior art coupling arrangements 19 for connecting relatively small diameter tubes 20 such as brake tubes to fittings 21 by threaded insert-type connections 22 . The fittings 21 are crimped to a hose 23 which carries relatively high pressure hydraulic fluid. In FIG. 1, a part of a truck chassis or frame 24 retains the coupling 19 thereon with a bracket 25 to hold the coupling rigid with respect to the frame. The hose 23 is relatively flexible and may be retained to other portions of the chassis by clamps while the tubes 20 may also be retained to the chassis 24 by clamps 25 . One of the tubes 20 is attached to a hydraulically driven device such as a brake caliper 28 in a disk brake 29 . The present invention replaces the couplings 19 with a more reliable and more economical coupling arrangements. While a disk brake 29 is shown in FIG. 1, the invention has other uses for other types of hydraulic connections such as connections for clutches, and any other arrangement in which a flexible hose is connected to a rigid tube.
Referring now to FIGS. 2 and 3 which show in more detail the prior art coupling 19 of FIG. 1, it is seen that the threaded nut 22 is received in a threaded recess 31 of the fitting 21 while the hose 23 is crimped to the fitting via a crimping collar 32 . In the arrangement of FIG. 2, the tube 20 has a flared end 33 and the fitting 21 has an inverted or convex seat 34 . In the embodiment of FIG. 3, the fitting 21 ′ has a concave seat 34 ′ which receives a bubble end 33 ′ of the tube 20 ′. The externally threaded nut 22 ′ then threads into the threaded bore 31 ′ in the same way that the threaded nut 22 threads into the threaded bore 31 of FIG. 2 . In practice, the arrangements of FIGS. 2 and 3 tend to have multiple components.
Referring now to FIG. 4, in an attempt to avoid the expense and minimize the difficulties of a coupling 19 , such as the coupling of FIGS. 2 and 3, wherein an externally threaded nut 22 , 22 ′ must be threaded into a threaded bore 31 , 31 ′, the tube 20 ″ of FIG. 4 is press-fitted into a smooth recess 31 ″ of a fitting 21 ″ and copper brazed at juncture 36 . The fitting 21 ″ is then plated, which requires plating of an assembly that has the relatively long portion of the tube 20 ″ attached to the fitting 21 ″. In practice, the arrangement of FIG. 4 also tends to use an insertion tube 37 , which results in more part-to-part junctures that increase the number of potential leak paths.
Embodiments of the Invention: FIGS. 5 - 12
In order to improve upon the couplings illustrated in FIGS. 1-4 as well as other couplings, the present invention eliminates a need to physically join the components of the tube-to-hose couplings by hand at assembly plants, as well as reducing leak paths, component costs and part number counts. Moreover, as opposed to brazed tube designs, such as that of FIG. 4, tolerance control is increased, as is routing control.
Referring now to the first embodiment of the present invention illustrated in FIGS. 5-9, a high pressure integral tube coupling 40 enables a direct connection between a metal tube 50 and a flexible hose 23 (see FIG. 1 ), such as a high pressure resistant rubber hose, without a need for rotating threaded coupling components or brazing, thus eliminating parts or steps while retaining their function. As is seen in FIG. 5, the metal tube 50 is positioned within a body portion 51 of a fitting 52 to which the hose 23 of FIG. 1 is subsequently coupled by deforming a crimping collar 53 therearound so that the hose is axially retained within the fitting 52 and is radially sealed against an end portion 54 of the tube. The tube 50 corresponds to the tubes 20 shown in the prior art arrangements of FIGS. 1-4 and has an internal diameter of about 0.1250 inch, which internal diameter could range from about 0.125 to about 0.145 inch.
In order to retain the tube 50 in the fitting 52 , a back bead 56 is preferably seated within an annular bead pocket 58 formed in a back end 59 of the fitting 52 while a front bead 60 is preferably seated in a pocket 62 formed in front end 63 of the fitting located just before the crimping collar 53 . A smooth bore 66 extends completely through the fitting 52 into a cylindrical space 68 defined by the crimping collar 53 . While the pockets 58 and 62 are preferable, it is within the scope of this disclosure to form the coupling without the pockets by crimping the tube 50 directly against the radial end surfaces of the fitting (See FIG. 9 ).
The diameter d 1 , of the smooth bore 66 is slightly greater than the diameter d 2 of the tube 50 so that the tube slides through the smooth bore. While the diameter d 1 is slightly larger than the diameter of d 2 , it need only be large enough so that the d 2 will slide readily therethrough. There could, however, be a slight press fit of the tube 50 within the bore 66 .
The end 54 of the tube 50 has a reduced diameter portion 67 of a diameter d 3 which is slidably receivable within the bore 70 of the hose 23 and is of a length substantially equal to that of the crimping collar 53 . Consequently, the bore 70 of the hose 23 is supported during the crimping step which deforms the material 72 of the hose.
Referring now to FIGS. 6A-6D which illustrate the method fabricating and assembling the coupling 40 , it is seen that the metal tube 50 has its end portion 54 drawn to have the reduced diameter d 3 which is less than the diameter d 2 of the tube 50 . As is seen in FIG. 6B, the back bead 56 is formed by an applied force which pushes a portion 76 of the tube 50 back, thus forming a beaded area in proximity with line 78 .
As is seen in FIG. 6C, the thus deformed tube 50 is inserted through the smooth bore 66 of the fitting 52 so that the back bead 56 fits into the annular bead pocket 58 at the back end 59 of the body 51 of the fitting. The annular bead pocket 58 is formed in or machined in the back end 59 of the fitting and has a diameter substantially greater than the diameter d 2 of the smooth bore 66 . It is to be kept in mind that the bead pocket 58 is a desirable but optional feature. Referring now to FIG. 6D in combination with FIG. 6C, the front bead 60 is then formed by using an applied force to the tube 50 rearwardly so that a portion 80 of the tube 50 deforms into the front bead 60 which seats within the annular front bead pocket 62 at the front end 64 of the body 51 of fitting 52 . The structure of the tube 50 in the absence of the fitting 52 is shown in FIG. 7, while the structure of the fitting absent the tube is shown in FIG. 8 .
In the first embodiment of the invention, it is seen that the coupling 40 is accomplished by two axial deformations of the tube 50 , one prior to inserting the tube 50 into the fitting 52 and the other subsequent to the insertion. The final step is to radially crimp the crimping collar 53 which is a conventional one-step procedure. If the arrangement is to be used with the brake line of FIG. 1, the fitting 52 with the tube 50 connected thereto may be first inserted into an opening in the bracket 25 and a sliding clip slid into the annular groove 87 in the fitting 52 . The hose 23 is then inserted in the space 68 in the crimping collar 53 and the crimping collar crimped about the hose. By having a press fitting between the tube 50 and the fitting 52 , rotation of the fitting relative to the tube is eliminated while maintaining a fluid tight seal.
Preferably, the metal tube 50 is made of steel and is pre-coated by SAE-J527 Standards, sliding fit. Other materials which may be used are copper, nickel, NYLON® (polyamide) or polyvinyl fluoride. If relatively thick plastic coatings such as NYLON® are used, the coating preferably terminates before the first bead 56 ; however, as is seen in the third embodiment of FIGS. 10 and 11, can continue to bead 60 . The barbed or stem structure beyond the beads 56 and 60 has a controlled inside diameter as well as a controlled outside diameter which permits the assembly to pass the Federal Motor Vehicle Safety Standards for minimum fluid passage diameter. Moreover, the barb or stem structure can be produced either with or without annular grooves to increase tensile integrity of the coupling. Since the end 54 of the tube is received directly within the bore 70 of the hose 23 , potential leak paths which occur with additional elements, such as those in prior art threaded connections and brazed tubular supports, are eliminated.
Referring now to FIG. 9, there is shown a second embodiment of the invention, wherein the bead pockets 58 and 62 are deleted from the fitting 52 ′ so that beads 56 ′ and 60 ′ press directly against the radially extending back and front end surfaces 80 and 82 , respectively of the fitting 52 ′. Friction between the end surface 80 and back bead 56 and between the front end surface 82 and the front bead 60 prevents rotation of the tube 50 within the fitting. In addition, there is a slight friction fit between the tube 50 and the bore 66 ′ which provides a fluid seal.
Referring now to FIG. 10, there is shown a third embodiment of the invention wherein a tube 90 is inserted into a fitting 92 having a crimping collar 93 . The tube 90 has a necked down portion 94 joined thereto by a frusto-conical section or tapered 95 . The frusto-conical section 95 joins an intermediate section 96 just in front of a bead 97 . The fitting 92 has a smooth bore 100 that has an abutment surface 101 defined by an annular shoulder 102 therein that is disposed within in an annular recess 104 . As with the embodiment of FIGS. 5-9, the tube 90 is shoved into the fitting 92 (as shown in FIG. 6C) until the bead 97 abuts the shoulder 102 of the abutment surface 101 . An annular portion 106 of the wall of the recess 104 is then deformed by staking the portion 106 against the bead 97 to retain the tube 90 within the bore 100 of the fitting 92 . Thereafter, a portion 110 of a second annular recess 112 within the fitting proximate the crimping collar 93 is deformed against the tapered section 95 of the tube 90 to provide a tapered portion 113 of the bore 100 against which the tapered portion of the tube seats. This seals the tube 90 within the fitting 92 at substantially three locations, whereafter the hose 23 is secured within the fitting 92 by deforming the crimping collar 93 . The arrangement of the second embodiment of the invention shown in FIG. 10 is used substantially as the arrangement of the first embodiment shown in FIGS. 5-9. As with the embodiments of FIGS. 5-8 and 9 , the embodiment of FIG. 10 is used in situations such as that of FIG. 1 where a flexible hose 23 connects a source of hydraulic fluid to a tube 20 , which tube retains fluid which operates a hydraulic device, such as the calipers of a brake, or a clutch, or any other device requiring high pressure hydraulic fluid delivered via a flexible hose.
Referring now to FIGS. 11 and 12 A-D, there is shown a fourth embodiment of the invention wherein a metal tube 200 is coupled to the hose 23 by a fitting 202 to form a coupling 203 . The metal tube 200 has a drawn down portion 204 which has a relatively small outside diameter d 1 which is less than the outside diameter d 2 of a main portion 205 of the tube. In addition, the tube 200 has an annular bead 206 having a first axially facing surface 208 and a second axially facing surface 210 . Tube 200 is received through a smooth bore 212 in a body portion 213 of the fitting 202 and, if the metal tube does not have a plastic coating, may have an interference fit. Tube 200 is retained within the fitting 202 by abutment between the first surface 208 of the bead 206 with a shoulder 216 adjacent the bore 212 and by a swagged, staked or otherwise deformed annular portion 218 of the fitting 202 that forms a second abutment which engages the surface 210 of the bead. A surface of the second abutment faces away from hollow portion 230 . The fitting 202 and tube 200 are therefore prevented from any axial or rotational movement, one with respect to the other while also being provided with metal-to-metal fluid seals 219 and 216 which prevent entry of moisture and corrosive agents that might degrade the interior of the coupling.
Preferably, the main portion 205 of the metal tube 200 is coated or covered with a layer 220 of a plastic material such as, for example, a polyamide, i.e., NYLON®, which layer of plastic material terminates before or at the bead 206 leaving the bead uncoated for the metal-to-metal seal 219 with the fitting as well as leaving the small diameter portion 204 uncoated for ready receipt in the bore of the hose 23 . Examples of other plastic materials which may be used are polyvinylfluoride or polypropylene.
A preferred example of a tube configuration for the tube 200 comprises a base tube of SAE 1008/1010 mild steel with a layer of copper plating over which is a 10-15 μm 95% zinc/5% aluminum hot dip coating. The layer of plastic material 220 is preferably a layer of polyamide over a binder layer which is on average about 3.5 μm thick.
Referring now to FIGS. 12A-12D, preferred steps in assembling the coupling 203 are shown in sequence. As is seen in FIG. 12A, tube 200 is provided. Tube 200 is drawn to provide the small diameter portion 204 and to form frusto-conical portion 222 which joins the small diameter portion 201 to the remainder of the tube 200 . As is seen in FIG. 12B, the tube is deformed by pressing axially against the tube so that it bulges outwardly to form the bubble 206 generally in the location of the fiusto-conical portion 222 . If the entire tube 200 has previously been coated with a plastic layer 220 , the plastic layer is stripped from the insertion portion 204 and the bead 206 prior to drawing.
There are a number of methods to remove a portion of the plastic layer 220 from a portion of the tube 200 . These methods include applying mechanical cutting tools, abrasive wheels or brushes or using laser ablation, chemical solvents or water jet ablation. The tube 200 may be axially moved and rotated as the plastic and other non-metallic materials are stripped therefrom preferably prior to drawing or otherwise deforming the tube 200 .
Referring now to FIG. 12C, the fitting 202 is slid along the length of the tube 200 from its opposite end or, in the alternative, the tube is simply inserted into the bore 212 until the surface 208 on the bead 206 is abutted by the shoulder 216 that is adjacent the end of the bore. Preferably, the fit between the tube 200 and the bore 212 is a sliding fit with the plastic layer 220 sliding within the bore. The fit between the tube 200 and bore may be sufficiently tight to form a fluid tight seal. As is seen in FIG. 12D, the annular portion 218 of the wide portion of the bore 212 is then swaged, staked or otherwise deformed against the second face 210 of the bead 206 in order to form the coupling 203 which firmly retains the tube 200 within the fitting 202 and forms the metal-to-metal, fluid tight seal 219 therewith.
After the coupling 203 is formed, the hose 23 (FIG. 11) is inserted into a hollow portion 230 of the fitting 202 which forms a crimping collar that is unitary with the body portion 213 of the fitting. The crimping collar 230 is then deformed radially inwardly to retain the hose 23 permanently and non-rotatably in communication with the tube 200 .
By utilizing the arrangement of the present invention, tubes are retained within fittings, such as fittings for joining the tubes to hoses, utilizing mechanical steps which involve neither rotating the tube with respect to the fitting, brazing the tube to the fitting or using a retaining unit.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modification of the invention to adapt it to various usages and conditions. | Metal tubes, such as the small diameter metal tubes used in hydraulic braking systems, are connected to hoses also used in such systems by fittings which are configured to receive radially projecting beads on the metal tubes. Each of the fittings includes a body portion with a bore therethrough and a crimping collar which is unitary with the body portion. The body portion receives an insertion end of the tube therethrough, which insertion portion projects into the unitary crimping collar. A radially extending bead on the tube is received in a recess adjacent the bore through the body portion. In one embodiment, the tube is held in place by another bead which is seated in another recess at the opposite end of the bore. | 5 |
BACKGROUND
[0001] This invention relates to novel agents and novel methods for the treatment of perimenopausal and menopausal (climacteric) syndromes. Menopause occurs when the ovaries' production of estrogen begins to decline. As the body adapts to the reduced estrogen levels, menopausal (climacteric) syndromes becomes apparent. These symptoms may include hot flashes, palpitations, depression, anxiety, irritability, mood swings, lack of concentration, vaginal dryness, urgency of urination, and erratic menstrual periods.
[0002] Perimenopause is a period which is before actual menopause. At this time, the production of hormones such as estrogen and progesterone becomes irregular. During this period, the fertility of the female is significantly reduced. The perimenopausal period can last for a few months or for several years. Some clinicians maintain that perimenopause can last for as long as 5 to 15 years, while others refer to perimenopause as that period which is a 3 to 4 year span just before menopause. Either way, many women experience more symptoms during perimenopause than after menopause.
[0003] It is well known that climacteric symptoms and perimenopausal symptoms affect the quality of life of women and increases risk for cardiovascular events and osteoporosis. The decreased production of estrogen, associated with the perimenopausal and climacteric stages of life, is responsible for many undesirable physiological and psychic changes. Climacteric changes have been treated with a great variety of estrogens. For example, typical climacteric complaints, such as hot flashes and outbreaks of perspiration, insomnia, cardiovascular sensations, and sensations of dizziness are often treated by administration of synthetic estrogen (e.g., estradiol valerate). Psychic changes, manifesting themselves by emotional imbalance can likewise be eliminated by administration of synthetic estrogen. However, a disadvantage of using synthetic estrogen is that the treatment results in extensive proliferation of the endometrium, which leads, in turn, to undesirable uterine bleeding. The strong effect of estradiol valerate on the upper genital tract also limits the use of this compound. Furthermore, while estriol has a favorable effect on the lower genital tract (cervix uteri, vagina, and vulva), it has the disadvantage that typical complaints and psychic changes are not fully satisfactorily ameliorated. In addition, estrogen replacement therapy has been found to produce serious adverse effects as increased rate of cardiovascular diseases, thrombotic events and higher risk for breast and endometrial (genital tract) cancer. Bureau of Internal Affairs, Population Office (2002), Statistics of the Population, Web site of Population office, http://.ris.gov.tw/ch4/static/stI10-1-85-90; Li S, Holm K, Gulanick M, Lanuza D. Perimenopause and quality of life/commentary. Clinical Nursing Research 2000;9(1):6-26.
[0004] Because of these risks of existing therapy, there is a need to identify safe ways of enhancing quality of life of perimenopausal women, restoring the physiological and psychic balance as close as possible to normal.
[0005] One embodiment of the invention is directed to a method of reducing a climacteric symptom or a perimenopausal symptom in a female mammal - such as a human. The method comprises administering to the mammal an effective amount of a composition comprising proanthocyanidins. One preferred route of administration is oral administration. The composition may be, for example, a pill, a liquid extract, a food, a drink, or a beverage. The pill may be a capsule containing liquids or a solid pill. The liquid extract may be a concentrated extract. The food may be in the shape of a bar such as a chocolate (or other favor) bar, a semisolid such as a yogurt like substance, or an enriched food such as bread, rice, meat, gravy, cake and the like. The drink may be a health drink, or an enriched drink like based on a diary product (milk) or fruit juice. The beverage may be water, flavored water, soft drinks or an alcoholic drink.
[0006] The dosage that can be administered to a mammal may be between 10 mg per day to 6000 mg (6 grams) per day. In a preferred embodiment, the dosage is between 100 mg per day to 400 mg per day. In a more preferred embodiment, the dosage may be, for example, about 200 mg per day. The daily dosage described above may be split into multiple administrations such as, for example, two times a day, three times a day, or four times a day.
[0007] The composition comprising proanthocyanidins may be in the form of a plant material or may be obtained by synthesis (i.e., synthetic proanthocyanidins). For example, proanthocyanidins can be found in vegetable extracts, as well as in extracts of the bark of a maritime pine, the cones of cypresses, and the seeds and skin of grapes—an extract of each of these materials (i.e., pine bark extract, cypress cone extract, conifer extract, grape seed extract) would be suitable as a composition comprising proanthocyanidins.
[0008] In a preferred embodiment, the composition comprising proanthocyanidins may be a pine bark extract. The pine bark may be from P. pinaster, such as, for example, from Pycnogenol. In a preferred embodiment, the composition may contain proanthocyanidins at a concentration of 10% to 100% of total weight. For example, a Pycnogenol composition may be diluted or concentrated to contain 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 90% or 95% proanthocyanidins. Concentration may be performed using known methods such as column chromatography or affinity chromatography. Further, the Pycnogenol may be admixed with inactive ingredients to enhance solubility. These ingredients may include, for example, a protein or protein hydrolysates (e.g., degraded protein). The protein hydrolysate may have an average molecular weight of less than 5,000, less than 7,000, less than 10,000, less than 15,000, or less than 30,000 or a combination thereof. The combination thereof refers to a mixture of any two or more protein hydrolysates discussed above. For example, a mixture of protein hydrolysate of less than 7000 with a protein hydrolysate of less than 15,000. In one preferred embodiment, the protein or protein hydrolysate is collagen or partly degraded collagen.
[0009] In a preferred embodiment, the proanthocyanidins in the composition comprising proanthocyanidins is the sole active ingredient administered to the female mammal. That is, the female mammal is not treated with any external female hormone or hormone like substance by injection, by oral route, or by any method of administration. For example, the female mammal is not being treated with exogenous estrogen, phytoestrogen, and derivatives and functional analogs thereof of these hormones.
[0010] The methods of the invention are suitable for the treatment of female mammals that are in menopause—defined as not having a menstrual cycle for a period of one year. The method of the invention is also suitable for treatment of female mammals in the perimenopausal period. This period starts from approximately 15 years before menopause, 10 years before menopause, or 5 years before menopause in the typical woman. The average onset of menopause is about 50 years for a woman. Thus, the methods of the invention may be used for treating a woman who exhibits a perimenopausal symptom from the age of 35-50, 40-50 or 45-50.
[0011] The administration of the composition comprising may be for a period of 1 month, 2 months, 3 months, 6 months, or continuous (e.g., for as long as desired by the patient).
[0012] The symptoms to be treated, for any of the methods of the invention, include any and all the symptoms listed in Tables 5, 6, or 7. These undesirable symptoms include, at least, tiredness, headache, higher than normal urinary frequency, anxiety, vaginal dryness, menstrual problems, hot flashes, bloatedness, night sweat, backache, pain in limbs and depression. The treatment of a symptom include reducing the manifestation of the symptom, including, for example, reducing the frequency or severity of the symptom. Treatment may also include eliminating the symptom or delaying the onset of the symptom.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 depicts the frequency of symptoms for 155 perimenopausal women.
DETAILED DESCRIPTION OF THE INVENTION
[0014] It is understood that the term “pine bark extract” in this disclosure refers to a French maritime pine bark extract which is, for example, commercially available as Pycnogenol® (Horphag). The terms “Pycnogenolg”, “pine bark extract” and “French maritime pine bark extract” are interchangeable in this disclosure.
[0015] Pinus pinaster ( P. pinaster ) and Pinus maritima ( P. maritime ), are understood to refer to the same organism commonly called “French Maritime Pine.” Hence, these terms are interchangeable.
[0016] Proanthocyanidins designates a group of flavonoids that includes the subgroups procyanidins, prodelphinidins and propelargonidins. Proanthocyanidins are homogeneous or heterogeneous polymers consisting of the monomer units catechin or epicatechin, which are connected either by 4-8 or 4-6 linkages, to the effect that a great number of isomer proanthocyanidins exist. Typically, the proanthocyanidins oligomers have a chain length of 2-12 monomer units. Proanthocyanidins may be synthesized or extracted from a plant material. Nonlimiting examples of plant material sources of proanthocyanidins include grape seeds, grape skin, pine barks, ginkgo leaves, peanuts, and cocoa beans, tamarind, tomato, peanut, almond, apple, cranberry, blueberry, tea leaves.
[0017] A well-known product containing proanthocyanidins, which is available in trade as a preparation of a food supplement under the name Pycnogenol®, is an extract of the maritime pine bark ( Pinus pinaster ). Pycnogenol®, the extract from French maritime pine bark ( Pinus pinaster ) is a registered trademark belonging to Horphag Research, Ltd. Pycnogenol® is a standardized bark extract of the French maritime pine Pinus pinaster, Aiton, subspecies Atlantica des Villar (Pycnogenol®, Horphag Research Ltd., UK). The quality of this extract is specified in the United States Pharmacopeia (USP 28) (Maritime Pine Extract. In: United States Pharmacopeia. Rockville: United States Pharmacopeial Convention, Inc.; 2005. pp. 2115-2116). The extract consists of a concentrate of polyphenols, which are also contained in fruits and vegetables, but, in low concentrations. The polyphenols are composed from flavonoids, especially procyanidins, and phenolic acids. All these constituents possess the ability to inactivate free radicals. Rohdewald P. A review of the French maritime pine bark extract (Pycnogenol®), a herbal medication with a diverse pharmacology. Int J Clin Pharmacol Ther 2002;40(4):158-168. Between 65-75% of Pycnogenol® are procyanidins comprising of catechin and epicatechin subunits with varying chain lengths (Rohdewald P. A review of the French maritime pine bark extract (Pycnogenol), an herbal medication with a diverse clinical pharmacology. Int J Clin Pharmacol Ther 2002;40: 158-168). Other constituents are polyphenolic monomers, phenolic or cinnamic acids and their glycosides (Id.).
[0018] Menopause is defined as a minimum of twelve months without menstruation.
[0019] Perimenopause refers to a period of a few months, to several years and up to 15 years before menopause. That is, perimenopause may occur in a woman between 45 to 50 years of age, between 40 to 50 years of age, or between 35 to 50 years of age.
[0020] We decided to investigate the potential benefits of Pycnogenol for perimenopausal women. The results of our study, and a discussion of the results are listed below in the Examples section.
EXAMPLES
Example 1
Determining the Effectiveness in Using Pycnogenol for the Treatment of Climacteric or Perimenopausal Symptoms
[0021] As a basis of our study we evaluated on a group of 200 perimenopausal women in Taiwan the level of discomfort and the frequency of climacteric syndrome at enrollment. These values are compared with results obtained in other countries with perimenopausal women.
[0022] Patients and Methods
[0023] During a 3 and half years period (from January 2002 to July 2005), 200 perimenopausal women between 45-55 years old participated on the study.
[0024] Inclusion Criteria:
[0025] Menstrual cycles had disappeared for 3-11 months, but normal cycles appeared again. Patients were included according to hormone levels:
[0026] serum levels of FSH>30 IU/ml and estrogen E2 levels<20 pg/L. They were controlled for normal mammogram, endometrial thickness <6 mm, normal cervical smear (Pap-test).
[0027] Exclusion Criteria:
[0028] Systematic or acute diseases, hormone therapy, contraceptive medication, hormone substitution, oophrectomy, hysterectomy, illiteracy.
[0029] Participants were interviewed for socio-economical status, smoking and dietary habits and examined at first visit for BMI, heart rate, blood pressure, mammography, vaginal sonography and Pap test. Blood samples were taken for analysis with standard methods for total cholesterol, HDL, LDL, triglycerides, AST and ALT, FSH and estrogen levels were analyzed in samples taken on 3rd day of menstruation.
[0030] Total antioxidant status (TAS) was determined using a with Randox commercial kit, according to the method of Miller et al. Nicholas J. Miller, Catherine Rice-Evans, Michael J. Davies, Vimala Gopinathan, Anthony Milner. A novel method for measuring antioxidant capacity and its application to monitoring the antioxidant status in premature neonates. Clinical Science 1993; 84:407-412.
[0031] Patients visited clinic for screening, enrollment and 1, 3 and 6 months following start of treatment. At each visit, BMI, blood pressure, lipid profile and TAS were recorded, lipid profile was determined at start and after 3 and 6 month of treatment.
[0032] Medication
[0033] Patients received either 100 mg Pycnogenol® capsules or placebo twice daily over a period of 6 months. Capsules of Pycnogenol® and placebo, identical in shape and appearance, were prepared by Wide-Doctor, Int., Taiwan, and packaged with the same label. Patients were instructed to take the pills at breakfast and at dinner.
[0034] Compliance
[0035] During the first 3 months of treatment, researchers phoned each patient weekly to ensure compliance giving instructions about intake and questionnaire filling. From the 4 th month on, patients were phoned every two weeks until the end of the 6 th month.
[0036] Questionnaire
[0037] Women's Health Questionnaire, designed by Hunter (1992), was used by the subjects to describe level of discomfort and climacteric symptoms. Hunter M. The women's health questionnaire: a measure of physical and emotional well-being of mid-aged women. Psychology & Health 1992; 7(1):45-54. Patients delivered the filled forms at each visit to the investigators. Women's Health Questionnaire (WHQ) contains a total of 36 questions related to perimenopausal symptoms: 1. Somatic symptoms (7 items), 2. depressed mood (8 items), 3. vasomotor symptoms (2 items), 4. memory/concentration (3 items), 5 attractiveness (2 items), 6 anxiety (4 items), 7 sexual behavior (3 items), 8 sleep problems (3 items), 9 menstrual symptoms (4 items). Each symptom was evaluated according to its frequency of occurrence and discomfort level.
[0038] Points given for frequency: 4: never occurring; 3: sometimes occur; 2: frequently; 1 point: always occur. Points given for discomfort level: 4: no discomfort; 3: little discomfort; 2: clear discomfort; 1: heavy discomfort. The higher the score, the less pronounced was distress and dysfunction.
[0039] The reliability of the questionnaire has been tested before the start of our study. Item analysis of symptoms frequency was tested by calculating Cronbach's alpha coefficient, resulting in a high reliability of 0.94. For discomfort levels, Cronbach's alpha coefficient was 0.91, degree of re-testing was 0.85. After translation of the WHQ into Chinese we tested the translated questionnaire again for reliability and obtained a Cronbach's alpha coefficient of 0.899 for discomfort levels so that translation had no negative impact on the questionnaire.
[0040] Data Analysis
[0041] Data were analyzed by using SPSS (Statistical Package for the Social Science) for Windows 10.0 edition. Statistical analysis included descriptive statistics (age, and health conditions, other variables of the population) tested by paired t test. Differences in baseline performance between the two groups were tested with a one-way ANOVA test. A two-way ANOVA was performed with perimenopausal symptom scores obtained during treatment. Post-hoc comparisons were made with Sheffe's F-test. Significance was set at a probability value of <0.05.
[0042] Results
[0043] Pycnogenol® and placebo groups did not differ in respect to frequency of climacteric symptoms and severity of symptoms at enrollment; they were carefully matched in terms of age, body mass index, social-economic status and nicotine or caffeine consumption.
[0044] Statistical evaluation of placebo- and Pycnogenol® group (at this point, the group was designated to be treated with Pycnogenol but have not actually been administered any Pycnogenol) revealed no significant differences between groups (Table 1). Influences on antioxidant status—consumption of tea, fruits, vegetables—did not differ, nor differentiated between socio-economic status, BMI or blood pressure. BMI did not change significantly during treatment period.
[0045] Drop-Out Rate
[0046] From the 200 patients enrolled into the study, 175 patients completed the 6 months treatment period. From these 175 patients, only 155 completed all questionnaires and participated on all investigations, 80 patients in the Pycnogenol® group, 75 in the placebo group. The dropout rate was nearly the same for both groups and mainly caused by non-adherence to protocol (non compliance).
[0047] A total 45 patients dropped out from the study. 20 from the Pycnogenol® group and 25 from the placebo group. Among the 20 patients, one suffered from a car accident and one from pelvic infectious disease. From the 25 drop-outs in the placebo group, 2 moved from the city and one complained of weight gain during the study period. The other patients were excluded from evaluation because of lack of compliance. The drop-out rate was 22.5%. None of the patients terminated the study because of unwanted effects of treatment.
[0048] Results of blood pressure monitoring show a slight decrease of systolic and diastolic blood pressure for both groups without significant differences between groups (Table 2). In the lipid profile, triglyceride levels remained unaffected in both groups. HDL levels increased significantly relative to start in the Pycnogenol® group, however, difference to placebo was not significant. LDL values dropped significantly by 10% under Pycnogenol® treatment relative to start as well as compared to placebo (Table 2). These results indicate a lowering of the atherosclerotic index, i.e. the balance between HDL and LDL cholesterol, following treatment with Pycnogenol®.
[0049] During treatment with Pycnogenol® the total antioxidant status increased steadily and significantly relative to start. The values after 6 month of supplementation with Pycnogenol® were significantly higher compared to results of the placebo group (Table 2).
[0050] To get an overview about the most relevant climacteric symptoms of Taiwanese women, the means of the overall symptoms scores for 155 women from both groups before treatment had been calculated (Table 3). Both groups did not differ in severity of symptoms, expressed as symptom scores, at enrollment. At enrollment to the study, no statistically significant difference was observed between Pycnogenol®-group and placebo group in respect to frequency of symptoms, reported according in the WHQ, (Table 4).
[0051] Variation between frequency of the different symptoms ranges from “not that frequently” (2.3) to “rarely occurring” (3.3). Most frequent symptoms were somatic symptoms such as tiredness, headache and urinary frequency, anxiety, followed by sexual (vaginal dryness)and menstrual problems, whereas vasomotor symptoms (hot flashes) were rarely reported ( FIG. 1 ). About 25% of perimenopausal women complained frequently or sometimes of hot-flash. The comparison with frequency of symptoms in other countries shows some differences. Women in Italy complained during perimenopausal period most frequently of loss of memory, sleep disorder and vasomotor symptoms (hot flashes); Apolone G. Mosconi P. The Italian SF-36 Health Survey: translation, validation and norming. Journal of Clinical Epidemiology 1998; 51(11):1025-36. Data for women in England were similar. Wiklund I. Karlberg J. Lindgren R. Sandin K. Mattsson L A. A Swedish version of the Women's Health Questionnaire. A measure of postmenopausal complaints. Acta Obstetricia et Gynecologica Scandinavica 1993; 72(8):648-55.
[0052] During treatment, a rapid improvement of symptoms was reported from women in the Pycnogenol® group, starting after 1 month, Table 5. Only the symptom nausea did not change during treatment, whereas all other symptoms of the WHQ improved, in most cases statistically significant (p<0.01), compared to start of treatment. In the placebo group, no systematic statistically significant changes of symptoms were reported. Only occasionally symptoms improved after the first month of treatment significantly, however, later symptoms worsened, except for the question regarding poor memory. However, the increase in scores for the placebo group was clearly lower compared to the Pycnogenol® group.
[0053] The mean WHQ scores for the different categories of climacteric symptoms demonstrate the highly significant changes relative to start (p<0.01) in every category for each period of treatment with Pycnogenol® (Table 6). In most categories, placebo did not produce significant changes, except for memory and concentration and somatic symptoms. Sleep behavior and menstrual symptoms were significantly alleviated only at one point.
[0054] Pycnogenol® was evidently superior to placebo, especially in the categories attractiveness, sleep behavior, somatic problems and sexual problems (Table 6).
[0055] The difference in the frequency of symptoms at enrollment was not statistically significantly for both groups. Frequency of symptoms decreased continuously during treatment. After 6 months, the difference between Pycnogenol® group and placebo group became so clearly visible so that no statistical evaluation is required to demonstrate the advantage of Pycnogenol® treatment (Table 7). Whereas in the Pycnogenol® group reports for symptoms “always occur” and “sometimes occur” dropped down to zero, that frequency was still reported in the placebo group, at least as “sometimes occurring” after 6 months.
[0056] Patients did not report any undesirable side effects from the treatment with Pycnogenol®.
[0057] Discussion
[0058] The significant higher total antioxidant status (TAS) in blood of the Pycnogenol® group demonstrates that intake of Pycnogenol® increases indeed the antioxidant activity in blood. These results of cholesterol and TAS measurements suggest a positive, protective contribution of Pycnogenol® to vascular health.
[0059] Our evaluation of frequency of climacteric symptoms in perimenopausal women in Taiwan revealed somatic symptoms (tiredness, headache) as the most prominent symptoms, followed by anxiety and menstrual problems. Comparison with results obtained with the WHQ in other countries showed principal differences, as in Italian, Apolone G. Mosconi P. The Italian SF-36 Health Survey: translation, validation and norming. Journal of Clinical Epidemiology 1998; 51(11):1025-36, or English, Wiklund I. Karlberg J. Lindgren R. Sandin K. Mattsson L A. A Swedish version of the Women's Health Questionnaire. A measure of postmenopausal complaints. Acta Obstetricia et Gynecologica Scandinavica 1993; 72(8):648-55, women, the most important symptoms are vasomotor symptoms (hot-flash), loss of memory, attractiveness and sleep problems.
[0060] The results may lead one to suggest that Pycnogenol® could act perhaps as a phytoestrogen. Such hypothesis is unlikely for a number of reasons:
[0061] None of the known constituents of Pycnogenol®—catechin, taxifolin, phenolic acids, procyanidins is known to act as a phytoestrogen. These molecules do not show the linear arrangement of two hydroxy-group at the opposite ends of the molecule, which is characteristic for phytoestrogens.
[0062] Treatment of patients with endometriosis with Pycnogenol® improved symptoms, but did not alter estrogen levels (E2) during a treatment period of 48 weeks. Kohama T. Pycnogenol alleviates pain associated with pregnancy. Phytother Res 2006; in press. A phytoestrogen should lower estrogen levels by a feedback mechanism.
[0063] Furthermore, Pycnogenol® exerts positive effects on male erectile function, as demonstrated in a double blind, placebo-controlled study with patients suffering from erectile dysfunction. Durackova Z, Trebaticky B, Novotny V, Zitnanova A, Breza J. Lipid metabolism and erectile function improvement by Pycnogenol®, extract from the bark of Pinus pinaster in patients suffering from erectile dysfunction—a pilot study. Nutr Res 2003;23: 1189-1198. In cases of male infertility, supplementation with Pycnogenol® improved quality of sperms, Roseff S J. Improvement in Sperm Quality and Function with French Maritime Pine Tree Bark Extract. J Reprod Med 2002; 47:821-824, Stanislavov R, Nikolova V. Prelox® plus testosterone for achieve fertilization in previously infertile men. Eur Bull of Drug Research 2005; 13(l):7-13. In combination with L-arginine, Pycnogenol® normalized erectile function in 84% of men with erectile dysfunction, Stanislavov R, Nikolova V. Treatment of erectile dysfunction with Pycnogenol® and L -arginine. J Sex Marital Ther 2003; 29:207-213, Stanislavov R, Nikolova V. Prelox® plus testosterone for achieve fertilization in previously infertile men. Eur Bull of Drug Research 2005; 13(1):7-13. A phytoestrogen should show negative effects on erectile function. Thus, this is further evidence that Pycnogenol does not act as a phytoestrogen and is most probably not related to a hormonal effect.
[0064] In summary, the improvement of climacteric symptoms following 6 months supplementation with Pycnogenol® is very worthwhile, even when symptoms were only gradually improved, as frequency of symptoms was clearly reduced and, last not least, every category of symptoms was improved.
[0065] In the placebo group, a slight improvement of severity of symptoms and of frequency of symptoms was found, however, the changes relative to enrollment were minimum and seldom significant. The rather low placebo effect is very astonishing, when compared to the large placebo effects observed in studies with analgesics or antacids. This finding seems to demonstrate the reliability and robustness of the WHQ questionnaire.
[0066] In conclusion, perimenopausal symptoms according to the WHQ of Taiwanese women differ to some extent in frequency to reports from Europe. Antioxidant status and atherosclerotic index (ration LDL/HDL) were improved by Pycnogenol®. Supplementation with Pycnogenol® reduced clearly frequency of symptoms as well as severity of climacteric symptoms. As all symptoms were gradually improved without adverse effects, quality of life of perimenopausal women was ameliorated by Pycnogenol®.
[0067] All references, patents, and patent applications cited are hereby incorporated by reference in their entirety.
TABLE 1 BASELINE CHARACTERISTICS OF SUBJECTS Pycnogenol ® Placebo (Mean ± SD) (Mean ± SD) n = 80 n = 75 P value Mean age (y) 46.73(5.09) 47.02(4.22) 0.728 Height cm 156.04(5.00) 155.15(5.76) 0.340 Weight kg Enrollment 58.27(8.16) 57.50(7.28) 0.477 After 6 57.97(8.61) 57.32(7.25) months Mean change −0.30 −0.18 BMI (kg/m 2 ) Enrollment 24.12(3.07) 24.06(2.84) 0.269 After 6 23.90(3.33) 24.12(2.84) months Mean change −0.22 0.06 Systolic blood pressure 116.37(14.10) 116.38(15.10) 0.996 (mmHg) Diastolic blood pressure 72.14(9.08) 72.43(8.45) 0.849 (mmHg) n(%) n(%) Coffee intake Every day 5(7.2) 4(6.5) 0.784* >4 times/ 0(0.0) 2(3.2) per week 2-3 times/ 13(18.8) 12(19.4) per week <1 time/ 34(49.3) 29(46.8) per week None 17(24.6) 15(24.2) Tea intake Every day 17(25.8) 18(30.5) 0.909* >4 times/ 8(12.1) 8(13.6) per week 2-3 times/ 26(39.4) 14(23.7) per week <1 time/ 11(16.7) 13(22.0) per week None 4(6.1) 6(10.2) Smokers % of group 1(1.4) 3(4.6) 0.278 Employee % of group 15(24.2) 14(24.1) 0.994 Worker % of group 16(25.8) 12(20.7) 0.512 *The p values of 0.784 and 0.909 refer to differences of the coffee and tea drinking habits between the Pycnogenol ® and placebo group, indicating no group differences for caffeine consumption.
[0068]
TABLE 2
BLOOD PRESSURE, LIPID PROFILE AND ANTIOXIDANT STATUS DURING
INTAKE OF PYCNOGENOL ® OR PLACEBO
Pycnogenol ®
Placebo
Enrollment
1 month
3 months
6 months
Enrollment
1 month
3 months
6 months
Systolic blood
116.37
113.41
110.27***
111.86**
116.38
115.00
112.68**
114.36
Pressure
(14.10)
(14.78)
(12.75)
(14.09)
(15.10)
(12.53)
(13.68)
(11.65)
Diastolic blood
72.14
70.18
69.37*
69.58*
72.43
71.02
69.68**
71.71
Pressure
(9.08)
(7.79)
(8.30)
(9.61)
(8.45)
(9.20)
(8.65)
(6.84)
HDL
44.70
—
45.31**
46.75*
43.40
—
44.19
44.23
(10.40)
(7.31)
(8.08)
(7.99)
(7.54)
(9.63)
LDL
111.44
—
105.27 kk
100.41* kkk
120.12
—
126.34
121.85
(29.62)
(25.16)
(24.24)
(38.01)
(45.52)
(29.00)
Triglyceride
90.37
—
99.32
94.46
113.13
—
114.44
114.09
(60.26)
(48.45)
(55.04)
(76.59)
(75.37)
(68.56)
TAS
1.42
1.48**
1.49**
1.55*** kk
1.41
1.45*
1.44
1.43
(0.13)
(0.14)
(0.14)
(0.55)
(0.13)
(0.15)
(0.14)
(0.14)
Mean difference to start is significant at the level 0.05*, 0.01**, 0.001***. Mean difference to placebo is significant at the level 0.01 kk , 0.001 kkk .
(Independent samples T-test)
BLOOD PRESSURE, LIPID PROFILE AND ANTIOXIDANT STATUS DURING
INTAKE OF PYCNOGENOL ® OR PLACEBO (ANOVA)
Pycnogenol ®
Placebo
Post
Post
Hoc
Hoc
Enrollment
1 month
3 months
6 months
p value
Tests
Enrollment
1 month
3 months
6 months
p value
Tests
Systolic blood
116.37
113.41
110.27
111.86
0.103
116.38
115.00
112.68
114.36
0.552
Pressure
(14.10)
(14.78)
(12.75)
(14.09)
(15.10)
(12.53)
(13.88)
(11.65)
Diastolic blood
72.14
70.18
69.37
69.58
0.267
72.43
71.02
69.68
71.71
0.382
Pressure
(9.08)
(7.79)
(8.30)
(9.61)
(8.45)
(9.20)
(8.65)
(6.84)
HDL
44.70
—
45.31
46.75
0.667
43.40
—
44.19
44.23
0.949
(10.40)
(7.31)
(8.08)
(7.99)
(7.54)
(9.63)
LDL
111.44
—
105.27
100.41
0.206
120.12
—
126.34
121.85
0.858
(29.62)
(25.16)
(24.24)
(38.01)
(45.52)
(29.00)
Triglyceride
90.37
—
99.32
94.46
0.981
113.13
—
114.44
114.09
0.942
(60.26)
(48.45)
(55.04)
(76.59)
(75.37)
(68.56)
TAS
1.42
1.48
1.49
1.55
0.000
4 > 1
1.41
1.45
1.44
1.43
0.321
(0.13)
(0.14)
(0.14)
(0.15)
(0.13)
(0.15)
(0.14)
(0.14)
TWO-WAY ANOVA FOR BLOOD PRESSURE, TAS AND LIPID PROFILES
BETWEEN THE ANTIOXIDENT GROUP(AG) AND PLACEBO GROUP(PG).
group
timing
group * timing
Post Hoc Tests
Systolic blood pressure
1.487
2.569
0.204
Diastolic blood pressure
1.162
2.110
0.239
HDL
2.720
0.766
0.206
LDL
21.223***
0.645
1.461
AG < PG
Triglyceride
5.130*
0.038
0.032
AG < PG
TAS
13.114***
5.335**
2.503
AG > PG t2, t4 > t1
*The mean difference is significant at the 0.05 level.
**The mean difference is significant at the 0.01 level.
***The mean difference is significant at the 0.001 level.
[0069]
TABLE 3
CLIMACTERIC SYMPTOMS AT ENROLLMENT FOR BOTH
GROUPS
Pycnogenol ® group
Placebo group
(n = 80)
(n = 75)
Enrollment
Enrollment
Depressed
Miserable and sad
3.15
3.11
(0.80)
(0.85)
Loss of interest in things
2.97
3.08
(0.89)
(0.82)
Still enjoy the things
2.91
2.98
(0.97)
(0.77)
Life not worth living
3.28
3.17
(0.82)
(0.90)
Have a good appetite
3.12
3.11
(0.87)
(0.86)
Irritability
2.46
2.50
(0.75)
(0.69)
Worry about growing old
2.50
2.36
(0.96)
(0.90)
Reduced well-being
2.85
3.03
(0.85)
(0.91)
Sleep
Restlessness
2.65
2.76
(0.85)
(0.82)
Early morning wakening
2.50
2.52
(0.81)
(0.90)
Difficulty getting off to sleep
2.59
2.41
(0.98)
(0.98)
Anxiety
Panicky feelings
3.03
3.08
(0.86)
(0.60)
Anxiety leaving house alone
3.19
3.31
(0.91)
(0.83)
Palpitation
2.55
2.76
(0.83)
(0.84)
Feel tense/wound up
2.60
2.78
(0.89)
(0.82)
Menstrual
Breast tenderness
3.09
3.05
(0.85)
(0.76)
Abdominal cramps
3.07
3.12
(0.84)
(0.74)
Heavy bleeding
2.59
2.50
(0.96)
(0.95)
Bloatedness
2.71
3.30
(0.99)
(0.46)
Vasomotor
Hot flashes
3.37
3.20
(1.00)
(1.02)
Night sweats
3.38
3.48
(0.91)
(0.73)
Somatic
Headaches
2.20
2.63
(0.83)
(0.91)
Tiredness
2.07
1.98
(0.74)
(0.80)
Dizzy
2.57
2.40
(0.86)
(1.00
Backache/pains in
2.26
2.33
limbs
(0.88)
(0.86)
Nausea
3.36
3.23
(0.77)
(0.85)
Pain and needles in
3.10
3.00
hands & feet
(0.97)
(1.00)
Urinay frequency
2.63
2.35
(0.99)
(0.98)
Sexual
Loss of sexual
2.67
2.51
interest
(0.85)
(0.81)
Dissatisfaction
3.08
3.04
(0.76)
(0.68)
Vaginal dryness
2.41
2.61
(0.93)
(0.84)
Attractiveness
Not lively
2.18
2.39
(0.82)
(0.76)
Feeling unattractive
2.35
2.50
(1.02)
(0.85)
Memory
Clumsiness
2.88
3.10
(0.83)
(0.78)
Difficulty in
2.36
2.61
concentrating
(0.85)
(0.70)
Poor memory
1.93
2.02
(0.82)
(0.83)
[0070]
TABLE 4
FREQUENCY OF SYMPTOMS FOR PERIMENOPAUSAL
WOMEN BEFORE ENROLLMENT (%)
Pycnogenol ® (n = 80)
Placebo group(n = 75)
definitely
sometimes
not much
not at all
definitely
sometimes
not much
not at all
p value
Miserable and sad
1.5
20.6
39.7
38.2
4.6
16.9
41.5
36.9
0.783
Loss of interest in thing
6.0
22.4
40.3
31.3
3.1
20.0
43.1
33.8
0.473
Still enjoy the things
30.4
42.0
15.9
11.6
25.0
51.6
20.3
3.1
0.640
Life not worth living
2.9
14.5
34.8
47.8
3.1
23.4
26.6
46.9
0.489
Have a good appetite
39.1
37.7
18.8
4.3
39.1
35.9
21.9
3.1
0.965
Irritability
6.0
50.7
34.3
9.0
4.7
46.9
42.2
6.3
0.767
Worry about growing old
19.1
38.2
27.9
14.7
20.2
36.9
33.8
9.2
0.715
Reduced well-being
8.8
17.6
52.9
20.6
7.8
15.6
42.2
34.2
0.246
Restlessness
8.7
39.1
37.7
14.5
6.2
40.0
38.5
15.4
0.724
Early morning wakening
11.4
34.3
45.7
8.6
15.4
30.8
41.5
12.3
0.964
Difficulty getting off to sleep
13.8
36.9
27.7
21.5
21.9
32.8
31.3
14.1
0.264
Panicky feelings
2.9
26.5
35.3
35.3
3.1
18.5
46.2
32.3
0.742
Anxiety leaving house alone
6.0
14.9
32.8
46.3
3.1
14.1
31.3
51.6
0.439
Palpitation
5.8
44.9
33.3
15.9
4.7
42.2
34.4
17.2
0.592
Feel tense/wound up
9.0
40.3
32.8
17.9
6.3
46.9
29.7
17.2
0.901
Breast tenderness
1.5
26.9
32.8
38.8
6.2
26.2
38.5
29.2
0.233
Abdominal cramps
4.3
18.6
42.9
34.3
6.2
23.1
36.9
33.8
0.565
Heavy bleeding
19.6
33.3
33.3
13.7
18.0
28.0
50.0
14.0
0.645
Bloatedness
9.1
39.4
22.7
28.8
11.1
31.7
28.6
28.6
0.847
Hot flashes
9.0
14.9
25.4
50.7
7.8
25.0
20.3
46.9
0.510
night sweats
3.2
19.0
14.3
63.5
1.8
14.5
25.5
41.1
0.481
Headaches
14.7
48.5
27.9
8.8
15.9
31.7
39.7
12.7
0.232
Tiredness
17.6
63.2
13.2
5.9
29.2
46.2
21.5
3.1
0.507
Dizzy
7.1
45.7
30.0
17.1
23.1
27.7
21.5
3.1
0.286
Backache/pains in limbs
18.8
53.6
15.9
11.6
18.5
49.2
23.1
9.2
0.854
Nausea
1.4
13.0
33.3
52.2
3.1
17.2
32.7
46.9
0.363
Pain and needles in hands &
7.5
19.4
28.4
44.8
9.8
19.7
31.1
39.3
0.550
feet
Urinary frequency
12.7
34.9
28.6
23.8
24.2
27.4
37.1
11.3
0.114
Loss of sexual interest
7.6
36.4
39.4
16.7
6.3
41.3
38.1
14.3
0.742
Dissatisfaction
1.9
19.2
48.1
30.8
1.9
15.1
60.4
22.6
0.781
Vaginal dryness
19.3
40.4
28.1
12.3
7.3
49.1
29.1
14.5
0.296
Not lively
19.4
49.3
25.4
6.0
17.2
39.1
37.5
6.3
0.304
Feeling unattractive
25.4
28.6
31.7
14.3
7.5
22.6
54.7
15.1
0.368
Clumsiness
3.0
31.8
39.4
25.8
7.7
29.2
40.0
23.1
0.533
Difficulty in concentrating
16.7
37.9
37.9
7.6
10.9
51.6
28.1
9.4
0.977
Poor memory
31.3
50.7
11.9
6.0
26.6
51.6
15.6
6.3
0.532
[0071]
TABLE 5
CHANGE IN CLIMACTERIC SYMPTOMS BY WHQ SCORES BETWEEN
PYCNOGENOL ® AND PLACEBO GROUPS FROM ENROLLMENT
TO THE 1, 3, AND 6 MONTHS OF STUDY
Pycnogenol ® group(n = 80)
Enroll-
placebo group(n = 75)
Ment
1 month
3 months
6 months
Enrollment
1 month
3 months
6 months
Depressed
Miserable and
3.15
3.42**
3.38*
3.40*
3.11
3.07
3.15
3.07
sad
(0.80)
(0.58)
(0.53)
(0.49)
(0.85)
(0.90)
(0.79)
(0.89)
Loss of interest
2.97
3.19
3.18
3.26
3.08
3.04
3.14
3.02
in things
(0.89)
(0.66)
(0.44)
(0.44)
(0.82)
(0.86)
(0.82)
(0.81)
Still enjoy the
2.91
3.28**
3.17*
3.38**
2.98
2.98
2.78
2.85
things
(0.97)
(0.70)
(0.56)
(0.49)
(0.77)
(0.97)
(0.92)
(0.91)
Life not worth
3.28
3.30
3.46
3.45
3.17
3.14
3.11
3.28
living
(0.82)
(0.78)
(0.54)
(0.50)
(0.90)
(0.84)
(0.91)
(0.86)
Have a good
3.12
3.22
3.20
3.35
3.11
3.07
3.02
2.81
appetite
(0.87)
(0.68)
(0.57)
(0.48)
(0.86)
(0.93)
(0.92)
(1.11)
Irritability
2.46
2.95***
3.14***
3.12***
2.50
2.73
2.64
2.64
(0.75)
(0.65)
(0.35)
(0.32)
(0.69)
(0.75)
(0.67)
(0.73)
Worry about
2.50
2.65
2.88*
3.17***
2.36
2.62*
2.43
2.52
growing old
(0.96)
(0.94)
(0.73)
(0.62)
(0.90)
(0.91)
(0.77)
(0.77)
Reduced well-
2.85
3.28***
3.28**
3.23**
3.03
3.25*
3.04
2.95
being
(0.85)
(0.64)
(0.58)
(0.43)
(0.91)
(0.76)
(0.92)
(0.86)
Sleep
Restlessness
2.65
2.98**
3.08***
3.16***
2.76
2.86
2.85
2.78
(0.85)
(0.53)
(0.49)
(0.62)
(0.82)
(0.75)
(0.72)
(0.96)
Early morning
2.50
2.73*
3.10***
3.14***
2.52
2.55
2.57
2.48
wakening
(0.81)
(0.78)
(0.72)
(0.60)
(0.90)
(0.76)
(0.81)
(0.86)
Difficulty getting
2.59
3.20***
3.48***
3.61***
2.41
2.58*
2.50
2.41
off to sleep
(0.98)
(0.79)
(0.60)
(0.74)
(0.98)
(0.99)
(1.01)
(0.86)
Anxiety
Panicky feelings
3.03
3.37**
3.29*
3.30*
3.08
2.88
2.96
3.10
(0.86)
(0.57)
(0.50)
(0.46)
(0.60)
(0.81)
(0.84)
(0.85)
Anxiety leaving
3.19
3.31
3.43
3.47
3.31
3.16
3.11
3.07
house alone
(0.91)
(0.76)
(0.58)
(0.50)
(0.83)
(0.88)
(0.88)
(0.93)
Palpitation
2.55
3.11***
3.20***
3.17***
2.76
2.80
2.67
2.74
(0.83)
(0.64)
(0.51)
(0.61)
(0.84)
(0.85)
(0.79)
(0.84)
Feel tense/
2.60
3.08***
3.15***
3.14**
2.78
2.64
2.61
2.58
wound up
(0.89)
(0.67)
(0.46)
(0.35)
(0.82)
(0.88)
(0.79)
(0.85)
Menstrual
Breast tenderness
3.09
3.27**
3.33**
3.19***
3.05
3.11
2.96
2.91
(0.85)
(0.62)
(0.55)
(0.39)
(0.76)
(0.79)
(0.79)
(0.90)
Abdominal cramps
3.07
3.33*
3.33
3.33
3.12
3.15
3.04
2.98
(0.84)
(0.57)
(0.55)
(0.48)
(0.74)
(0.78)
(0.81)
(0.91)
Heavy bleeding
2.59
2.81
3.00
3.16*
2.50
2.50
2.55
2.50
(0.96)
(0.82)
(0.48)
(0.37)
(0.95)
(0.85)
(0.93)
(0.90)
Bloatedness
2.71
3.10***
3.12**
3.30***
2.75
2.69
2.98
2.93
(0.99)
(0.62)
(0.48)
(0.46)
(1.00)
(0.94)
(0.87)
(0.91)
Vasomotor
Hot flashes
3.37
3.63**
3.68**
3.86***
3.20
3.09
3.19
3.25
(1.00)
(0.69)
(0.57)
(0.60)
(1.02)
(0.89)
(0.77)
(0.74)
night sweats
3.38
3.52
3.62
3.65
3.48
3.40
3.37
3.43
(0.91)
(0.67)
(0.53)
(0.48)
(0.73)
(0.81)
(0.74)
(0.68)
Somatic
Headaches
2.20
2.94***
3.08***
3.13***
2.63
2.60
2.67
2.73
(0.83)
(0.72)
(0.65)
(0.58)
(0.91)
(0.53)
(0.83)
(0.90)
Tiredness
2.07
2.89***
3.04***
3.04***
1.98
2.24*
2.32*
2.28
(0.74)
(0.69)
(0.50)
(0.39)
(0.80)
(0.74)
(0.73)
(0.70)
Dizzy
2.57
2.92**
3.08***
3.23***
2.40
2.70*
2.68
2.71
(0.86)
(0.70)
(0.64)
(0.53)
(1.00)
(0.78)
(0.84)
(0.81)
Backache/pains in
2.26
2.84***
3.00***
3.16***
2.33
2.43
2.43
2.28
limbs
(0.88)
(0.71)
(0.66)
(0.62)
(0.86)
(0.85)
(0.74)
(0.68)
Nausea
3.36
3.33
3.27
3.35
3.23
3.24
3.28
3.14
(0.77)
(0.72)
(0.53)
(0.48)
(0.85)
(0.74)
(0.71)
(0.87)
Pain and needles
3.10
3.32
3.31
3.40*
3.00
3.09
3.24
3.12
In hands & feet
(0.97)
(0.64)
(0.58)
(0.50)
(1.00)
(0.82)
(0.80)
(0.80)
Urinary frequency
2.63
3.10***
3.14***
3.12**
2.35
2.48
2.60
2.62*
(0.99)
(0.62)
(0.54)
(0.33)
(0.98)
(0.99)
(0.97)
(0.94)
Sexual
Loss of sexual
2.67
2.98**
3.23***
3.21***
2.51
2.69
2.75
2.65
interest
(0.85)
(0.71)
(0.62)
(0.66)
(0.81)
(0.72)
(0.84)
(0.88)
Dissatisfaction
3.08
3.20**
3.31*
3.29**
3.04
2.92
3.17
3.29
(0.76)
(0.74)
(0.61)
(0.46)
(0.68)
(0.70)
(0.70)
(0.53)
Vaginal dryness
2.41
2.92***
2.98***
3.18***
2.61
2.61
2.43
2.42
(0.93)
(0.74)
(0.62)
(0.64)
(0.84)
(0.83)
(0.83)
(0.82)
Attractiveness
Not lively
2.18
2.69***
2.94***
3.05***
2.39
2.46
2.57
2.50
(0.82)
(0.85)
(0.51)
(0.22)
(0.76)
(0.75)
(0.70)
(0.85)
Feeling
2.35
2.85***
3.02***
3.13***
2.50
2.77*
2.82
2.61
unattractive
(1.02)
(0.80)
(0.61)
(0.34)
(0.85)
(0.80)
(0.81)
(0.89)
Memory
Clumsiness
2.88
3.03
3.12
3.09
3.10
2.96
2.88
2.78
(0.83)
(0.72)
(0.52)
(0.29)
(0.78)
(0.82)
(0.76)
(0.89)
Difficulty in
2.36
2.78**
3.06***
3.10***
2.61
2.72
2.51
2.36
concentrating
(0.85)
(0.81)
(0.47)
(0.30)
(0.70)
(0.74)
(0.77)
(0.80)
Poor memory
1.93
2.74***
2.92***
3.00***
2.02
2.22*
2.23
2.33
(0.82)
(0.75)
(0.53)
(0.40)
(0.83)
(0.90)
(0.73)
(0.82)
Values are presented as mean(S.D.)
*The mean difference is significant at the 0.05 level.
**The mean difference is significant at the 0.01 level.
***The mean difference is significant at the 0.001 level.
Differences are evaluated versus enrollment.
CHANGE IN CLIMACTERIC SYMPTOMS BY WHQ SCORES BETWEEN PYCNOGENOL ® AND
PLACEBO GROUPS FROM ENROLLMENT TO THE 1, 3, AND 6 MONTHS OF STUDY
Pycnogenol ® group(n = 80)
Post Hoc
Enrollment
1 month
3 months
6 months
F
Tests
Miserable and sad
3.15(0.80)
3.42(0.58)
3.38(0.53)
3.40(0.49)
2.552
Loss of interest in thing
2.97(0.89)
3.19(0.66)
3.18(0.44)
3.26(0.44)
2.055
Still enjoy the things
2.91(0.97)
3.28(0.70)
3.17(0.56)
3.38(0.49)
4.418**
T2.4 > 1
Life not worth living
3.28(0.82)
3.30(0.78)
3.46(0.54)
3.45(0.50)
1.065
Have a good appetite
3.12(0.87)
3.22(0.68)
3.20(0.57)
3.35(0.48)
1.013
Irritability
2.46(0.75)
2.95(0.65)
3.14(0.35)
3.12(0.32)
17.641***
T2.3.4 > 1
Worry about growing old
2.50(0.96)
2.65(0.94)
2.88(0.73)
3.17(0.62)
9.631***
t3 > 1,
t4 > 1.2
Reduced well-being
2.85(0.85)
3.28(0.64)
3.28(0.58)
3.23(0.43)
5.874**
T2.3.4 > 1
Restlessness
2.65(0.85)
2.98(0.53)
3.08(0.49)
3.16(0.62)
10.709***
T2.3.4 > 1
Early morning wakening
2.50(0.81)
2.73(0.78)
3.10(0.72)
3.14(0.60)
11.604***
t3 > 1.2,
t4 > 1.2
Difficulty getting off to
2.59(0.98)
3.20(0.79)
3.48(0.60)
3.61(0.74)
28.887***
T2 > 1, t3 > 1,
sleep
t4 > 1.2.
Panicky feelings
3.03(0.86)
3.37(0.57)
3.29(0.50)
3.30(0.46)
3.540*
T2 > 1
Anxiety leaving house
3.19(0.91)
3.31(0.76)
3.43(0.58)
3.47(0.50)
1.822
alone
Palpitation
2.55(0.83)
3.11(0.64)
3.20(0.51)
3.17(0.61)
15.849***
T2.3.4 > 1
Feel tense/wound up
2.60(0.89)
3.08(0.67)
3.15(0.46)
3.14(0.35)
9.970***
T2.3.4 > 1
Breast tenderness
3.09(0.85)
3.27(0.62)
3.33(0.55)
3.19(0.39)
1.546
Abdominal cramps
3.07(0.84)
3.33(0.57)
3.33(0.55)
3.33(0.48)
2.628
Heavy bleeding
2.59(0.96)
2.81(0.82)
3.00(0.48)
3.16(0.37)
4.433**
T4 > 1
Bloatedness
2.71(0.99)
3.10(0.62)
3.12(0.48)
3.30(0.46)
7.126***
t2.3.4 > 1
Hot flashes
3.37(1.00)
3.63(0.69)
3.68(0.57)
3.86(0.60)
10.889
t2.3.4 > 1
night sweats
3.38(0.91)
3.52(0.67)
3.62(0.53)
3.65(0.48)
1.713
Headaches
2.20(0.83)
2.94(0.72)
3.08(0.65)
3.13(0.58)
20.583***
t2.3.4 > 1
Tiredness
2.07(0.74)
2.89(0.69)
3.04(0.50)
3.04(0.39)
43.831***
t2.3.4 > 1
Dizzy
2.57(0.86)
2.92(0.70)
3.08(0.64)
3.23(0.53)
10.463***
t2.3.4 > 1
Backache/pains in limbs
2.26(0.88)
2.84(0.71)
3.00(0.66)
3.16(0.62)
23.428***
t2.3.4 > 1
Nausea
3.36(0.77)
3.33(0.72)
3.27(0.53)
3.35(0.48)
0.189
Pain and needles in hands &
3.10(0.97)
3.32(0.64)
3.31(0.58)
3.40(0.50)
1.835
feet
Urinary frequency
2.63(0.99)
3.10(0.62)
3.14(0.54)
3.12(0.33)
7.214***
t2.3.4 > 1
Loss of sexual interest
2.67(0.85)
2.98(0.71)
3.23(0.62)
3.21(0.66)
9.507***
t2.3.4 > 1
Dissatisfaction
3.08(0.76)
3.20(0.74)
3.31(0.61)
3.29(0.46)
1.128
Vaginal dryness
2.41(0.93)
2.92(0.74)
2.98(0.62)
3.18(0.64)
12.728***
t2.3.4 > 1
Not lively
2.18(0.82)
2.69(0.85)
2.94(0.51)
3.05(0.22)
18.114***
t2.3.4 > 1
Feeling unattractive
2.35(1.02)
2.85(0.80)
3.02(0.61)
3.13(0.34)
10.769***
t2.3.4 > 1
Clumsiness
2.88(0.83)
3.03(0.72)
3.12(0.52)
3.09(0.29)
1.583
Difficulty in concentrating
2.36(0.85)
2.78(0.81)
3.06(0.47)
3.10(0.30)
13.610***
t2.3.4 > 1
Poor memory
1.93(0.82)
2.74(0.75)
2.92(0.53)
3.00(0.40)
33.868***
t2.3.4 > 1
Placebo group(n = 75)
Post
Hoc
Enrollment
1 month
3 months
6 months
F
Tests
Miserable and sad
3.11(0.85)
3.07(0.90)
3.15(0.79)
3.07(0.89)
0.092
Loss of interest in thing
3.08(0.82)
3.04(0.86)
3.14(0.82)
3.02(0.81)
0.169
Still enjoy the things
2.98(0.77)
2.98(0.97)
2.78(0.92)
2.85(0.91)
0.641
Life not worth living
3.17(0.90)
3.14(0.84)
3.11(0.91)
3.28(0.86)
0.297
Have a good appetite
3.11(0.86)
3.07(0.93)
3.02(0.92)
2.81(1.11)
0.939
Irritability
2.50(0.69)
2.73(0.75)
2.64(0.67)
2.64(0.73)
1.098
Worry about growing old
2.36(0.90)
2.62(0.91)
2.43(0.77)
2.52(0.77)
1.291
Reduced well-being
3.03(0.91)
3.25(0.76)
3.04(0.92)
2.95(0.86)
1.040
Restlessness
2.76(0.82)
2.86(0.75)
2.85(0.72)
2.78(0.96)
1.012
Early morning wakening
2.52(0.90)
2.55(0.76)
2.57(0.81)
2.48(0.86)
0.114
Difficulty getting off to
2.41(0.98)
2.58(0.99)
2.50(1.01)
2.41(0.86)
0.525
sleep
Panicky feelings
3.08(0.60)
2.88(0.81)
2.96(0.84)
3.10(0.85)
0.854
Anxiety leaving house
3.31(0.83)
3.16(0.88)
3.11(0.88)
3.07(0.93)
0.789
alone
Palpitation
2.76(0.84)
2.80(0.85)
2.67(0.79)
2.74(0.84)
0.321
Feel tense/wound up
2.78(0.82)
2.64(0.88)
2.61(0.79)
2.58(0.85)
0.524
Breast tenderness
3.05(0.76)
3.11(0.79)
2.96(0.79)
2.91(0.90)
0.622
Abdominal cramps
3.12(0.74)
3.15(0.78)
3.04(0.81)
2.98(0.91)
0.454
Heavy bleeding
2.50(0.95)
2.50(0.85)
2.55(0.93)
2.50(0.90)
0.031
Bloatedness
2.75(1.00)
2.69(0.94)
2.98(0.87)
2.93(0.91)
1.105
Hot flashes
3.20(1.02)
3.09(0.89)
3.19(0.77)
3.25(0.74)
0.451
night sweats
3.48(0.73)
3.40(0.81)
3.37(0.74)
3.43(0.68)
0.241
Headaches
2.63(0.91)
2.60(0.53)
2.67(0.83)
2.73(0.90)
0.685
Tiredness
1.98(0.80)
2.24(0.74)
2.32(0.73)
2.28(0.70)
2.361
Dizzy
2.40(1.00)
2.70(0.78)
2.68(0.84)
2.71(0.81)
1.706
Backache/pains in limbs
2.33(0.86)
2.43(0.85)
2.43(0.74)
2.28(0.68)
0.897
Nausea
3.23(0.85)
3.24(0.74)
3.28(0.71)
3.14(0.87)
0.220
Pain and needles in hands &
3.00(1.00)
3.09(0.82)
3.24(0.80)
3.12(0.80)
0.691
feet
Urinary frequency
2.35(0.98)
2.48(0.99)
2.60(0.97)
2.62(0.94)
0.831
Loss of sexual interest
2.51(0.81)
2.69(0.72)
2.75(0.84)
2.65(0.88)
0.519
Dissatisfaction
3.04(0.68)
2.92(0.70)
3.17(0.70)
3.29(0.53)
2.302
Vaginal dryness
2.61(0.84)
2.61(0.83)
2.43(0.83)
2.42(0.82)
0.515
Not lively
2.39(0.76)
2.46(0.75)
2.57(0.70)
2.50(0.85)
0.902
Feeling unattractive
2.50(0.85)
2.77(0.80)
2.82(0.81)
2.61(0.89)
1.666
Clumsiness
3.10(0.78)
2.96(0.82)
2.88(0.76)
2.78(0.89)
1.304
Difficulty in concentrating
2.61(0.70)
2.72(0.74)
2.51(0.77)
2.36(0.80)
2.247
Poor memory
2.02(0.83)
2.22(0.90)
2.23(0.73)
2.33(0.82)
1.444
Values are presented as mean(SD)
*The mean difference is significant at the 0.05 level.
**The mean difference is significant at the 0.01 level.
***The mean difference is significant at the 0.001 level.
[0072]
TABLE 6
MEAN CHANGE OF THE CLIMACTERIC SYMPTOMS EVALUATED BY THE WHQ
SCALE
Pycnogenol ® group(n = 80)
placebo group(n = 75)
Enrollment
1 month
3 months
6 months
Enrollment
1 month
3 months
6 months
Somatic
2.61
3.05 ===
3.14 ===
3.21 ===
2.57
2.69***
2.75**
2.69
problems
(0.97)
(0.69)
(0.50)
(0.41)
(1.00)
(0.89)
(0.87)
(0.87)
Depressed
2.89
3.16 ==
3.21 ===
3.29 ===
2.91
2.99*
2.91
2.89
(0.91)
(0.74)
(0.54)
(0.46)
(0.89)
(0.88)
(0.87)
(0.89)
Vasomotor
3.28
3.57 ==
3.64 ===
3.76** ===
3.27
3.25
3.28
3.34
problems
(0.96)
(0.59)
(0.50)
(0.43)
(0.91)
(0.86)
(0.76)
(0.71)
Memory/
2.39
2.85 ===
3.03 ===
3.06 ===
2.39
2.54*
2.64*
2.67*
Concentration
(0.92)
(0.77)
(0.51)
(0.25)
(0.90)
(0.85)
(0.82)
(0.82)
Attractiveness
2.26
2.77
2.98 ==
3.09 ===
2.41
2.58
2.63
2.59
(0.92)
(0.82)
(0.56)
(0.28)
(0.85)
(0.80)
(0.80)
(0.80)
Anxiety
2.85
3.22 ===
3.27 ===
3.27 ===
2.91
2.86
2.84
2.92
(0.91)
(0.58)
(0.50)
(0.44)
(0.88)
(0.85)
(0.87)
(0.88)
Sexual behavior
2.67
3.04 ==
3.18 ===
3.23 ===
2.71
2.76
2.81
2.79
(0.90)
(0.72)
(0.57)
(0.42)
(0.81)
(0.77)
(0.84)
(0.83)
Sleep
2.55
2.98 ===
3.22 ===
3.31 ===
2.51
2.67**
2.64
2.56
(0.88)
(0.63)
(0.50)
(0.47)
(0.91)
(0.85)
(0.86)
(0.90)
Menstrual
2.89
3.15 ===
3.21 ==
3.25 ===
2.80
2.81
2.96**
2.92
problems
(0.93)
(0.68)
(0.53)
(0.44)
(0.95)
(0.87)
(0.87)
(0.85)
All means of symptoms were stat. sign. different to enrollment for the Pycnogenol ®-group (p > 0.001).
Significant differences to enrollment for the placebo group are indicated as p < 0.05*, p < 0.01**, p < 0.001***
Significant differences to placebo are indicated by == p < 0.01, === p < 0.001.
[0073]
TABLE 7
FREQUENCY OF ALWAYS OCCURRING SYMPTOMS AT
ENROLLMENT AND AFTER 6 MONTHS TREATMENT (%)
Pycnogenol ®
Placebo
group
group
(months)
(months)
Symptom
0
6
0
6
Depressed
Miserable and sad
1.5
0
4.6
7.1
Loss of interest in thing
6.0
0
3.1
2.4
Still enjoy the things
30.4
38.1
25.0
24.4
Life not worth living
2.9
0
3.1
2.6
Have a good appetite
39.1
34.9
39.1
33.3
Irritability
6.0
0
4.7
4.8
Worry about growing old
19.1
0
20.2
7.1
Reduced well being
8.8
0
7.8
7.3
Sleep
Restlessness
8.7
0
6.2
9.8
Early morning wakening
11.4
0
15.4
14.3
Difficulty getting off to
13.8
0
21.9
19.0
sleep
Anxiety
Panicky feelings
2.9
0
3.1
2.4
Anxiety leaving house
6.0
0
3.1
4.9
alone
Palpitation
5.8
0
4.7
7.1
Feel tense/wound up
9.0
0
6.3
2.4
Menstrual
Breast tenderness
1.5
0
6.2
0
Abdominal cramps
4.3
0
6.2
0
Heavy bleeding
19.6
16.1
18.0
14.7
Bloatedness
9.1
0
11.1
7.3
Vasomotor
Hot flashes
9.0
0
7.8
0
Night sweats
3.2
0
1.8
0
Somatic
Headaches
14.7
0
15.9
7.1
Tiredness
17.6
0
29.2
11.6
Dizzy
7.1
0
23.1
9.8
Backache/pains in limbs
18.8
0
18.5
12.5
Nausea
1.4
0
3.1
7.1
Pain and needles in
7.5
0
9.8
4.8
hands & feet
Urinary frequency
12.7
0
24.2
11.9
Sexual
Loss of sexual interest
7.6
0
6.3
5.3
Dissatisfaction
1.9
0
1.9
0
Vaginal dryness
19.3
0
7.3
8.6
Attractiveness
Not lively
19.4
0
17.2
7.1
Feeling unattractive
25.4
0
7.5
14.6
Memory
Clumsiness
3.0
0
7.7
0
Difficulty in
16.7
0
10.9
2.4
concentrating
Poor memory
31.3
0
26.6
11.9 | The present invention is directed to novel methods of treating and reducing perimenopausal and climacteric symptoms using compositions comprising proanthocyanidins. In one embodiment, the methods provide for perimenopausal and climacteric symptom reduction without the use of female hormones or hormone like substances. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application and claims the benefit of U.S. Provisional Application No. 60/592,907, filed Jul. 29, 2004, the complete disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] In the healthcare industry, the availability of supply products is critical. Various systems exist that provide tracking of product usage, quick replenishment, user tracking, and patient tracking for billing purposes.
[0003] In addition, closed cabinet systems exist that prevent the removal of items without the entry of necessary data to perform the above tracking and prevent diversion or theft. Such a system is particularly applicable to the expensive items that are used in an operating room (OR) or cath lab. However, closed cabinet systems are also applicable to the high volume diversion of inexpensive items that are useful outside the healthcare facility such as batteries, bandages, shampoos, pens etc., where the user may consider the item too small to be considered “theft.”
[0004] In developing such systems, the challenge lies in balancing convenience and speed of access along with entering the necessary data to identify the user, the product and the account number or patient. Systems that dispense an individual product in the same manner as a candy machine, while desirable for convenience and security, are usually too expensive, require special packaging, and are not flexible in terms of the various size and configurations of product that need to be stocked in a hospital. They are also not very space efficient, since items are individually spaced and housed.
[0005] The use of RFID tags on products presents an opportunity to track individual products without the need for expensive dispensing systems. This is particularly true of expensive product where it is worth incurring the additional expense of applying the RFID tags. RFID tags are not currently available on products like bar codes, and are not likely to be generally available on healthcare products for many years.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of one embodiment of the present invention.
[0007] FIG. 2 is a side view of the embodiment of FIG. 1 .
[0008] FIG. 3 is a perspective view of another cabinet according to the invention.
BRIEF SUMMARY OF THE INVENTION
[0009] The invention provides both methods and apparatus for tracking, monitoring, protecting and safeguarding an inventory of products in a medical environment using RFID tags. In general, a cabinet is provided, the cabinet is constructed of a material sufficient to confine an RFID field generated from an RFID detector within the interior of a cabinet. The RFID detector scans the RFID tags of all products within the cabinet and generates an up-to-the-second inventory list of all products within the cabinet.
[0010] One particular aspect of the present invention provides a cabinet for housing an inventory of products in a medical environment. Each product within the cabinet is furnished an RFID tag that is unique to each product. The cabinet contains an RFID detector that generates an RFID field to scan the RFID tags of any product within the interior of the cabinet. A computer is coupled to the cabinet using Ethernet or a similar connection. The computer controls access to the cabinet and also communicates with a database having all the product information associated with each product's RFID tag.
[0011] In another aspect of the invention, the locking front door and the side panels of the cabinet are constructed of a transparent material such that the user may see into the cabinet without having to unlock and open the locking front door. The transparent material is manufactured to sufficiently contain the RFID field generated by the RFID detector within the interior of the cabinet. In one embodiment, the transparent material is an acrylic panel that has a coating comprising a number of vertical stripes of a silver based conductive ink and a number of horizontal stripes of a carbon based conductive ink arranged in a checkerboard pattern.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Described below are several exemplary embodiments of the invention. Although certain features are described, for ease of discussion, in relation to certain illustrated embodiments, those skilled in the art will appreciate, based on the disclosure herein, that various of the inventive features can be combined in accordance with many different embodiments of the invention. The illustrated embodiments below, therefore, are provided merely by way of example and should not be considered to limit the scope of the invention, which is defined only by the appended claims.
[0013] One aspect of the invention provides a cabinet with a locking door, or multiple individually controlled doors. In another aspect, the invention may provide a room (or multiple rooms) with an electronically controlled lock. The cabinet or room may contain multiple quantities of multiple items.
[0014] Certain items require specific shelving fixtures because certain items contain a liquid or metal content that prevents the transmission of sufficient signal strength to various tags on the products. Shelving fixtures are designed specifically for those items, or classes of items, to keep them suitably spaced apart. The spacing allows the RFID field to sufficiently energize all the tags in the system.
[0015] An RFID detector (or multiple detectors) is placed within the interior of the cabinet. RFID detector provides continuous monitoring of the items within the cabinet, e.g. identifying the data embedded on the tag of each product. The RFID detectors are capable of repeatedly scanning all products in a short time period, preferably less than two seconds. The system determines when an item has been removed by comparing the resulting list of items present with a previously generated item list. Since the scanning time period is preferably short, the invention provides any alerts prior to the user leaving the vicinity of the cabinet and the controlling computer.
[0016] The method of the present invention is preferable to existing systems, for example systems that detect an item being moved through a detecting portal area. In existing systems, any detection errors result in cumulative persistent errors that can only be corrected by a manual cycle count. The present invention avoids such errors by repeatedly taking an inventory of all products. In effect, the present invention is a repeated electronic full cycle count.
[0017] For multiple readings of RFID tags (and associated inventory) within a cabinet, it is advantageous to change the power distribution during each scan so that different power fields sweep the cabinet. Changing the power distribution provides additional and differentiated coverage, which also boosts the read accuracy.
[0018] In accordance with the present invention, the data associated with the RFID tag may take many forms. In one example, the invention uses a fixed ID number that is unique to the universe of tags used for all time. At an appropriate point in time, either at the cabinet or a separate workstation or system in central supply, this unique number is read into a database. Other data regarding the product is also entered into the database for subsequent retrieval. This data may include the item type ID, its UPN, expiration date, serial number, manufacturer or other parameters.
[0019] In another example, the RFID tags are WORM (write-once, read many) tags. In the case of a WORM tag, some or all of the data may be written once on the readable memory of the tag and thus can be read directly off the RFID tag. If the central database is unavailable, the product can still be identified. In addition, if access to the central server is unavailable, any user alerts given at the time of removal can be made by the local computer and cabinet system.
[0020] In yet another example, the RFID tag utilizes a writable tag. For a writable tag, information may be added to the product by the user. For example, the writable tag may contain information selected by the user such as the ID of the patient, the user ID, the date and time of removal, and the like. In all cases, the data formats associated with the tags should be compatible with the software systems, so that accurate reporting down to the item-level detail can be automated.
[0021] FIGS. 1 and 2 illustrate one example of a cabinet in accordance with the present invention. Cabinet 1 comprises a housing frame with locking doors 2 , with hinges 3 , handles 4 and indicator lights 5 . Transparent material 6 in the doors 2 allows the user to see through to the item on the shelves 8 , but mesh 7 prevents the radio frequency from the transmitter receiver assembly 9 mounted on the inside rear of the cabinet from propagating outside the cabinet. In another embodiment, the mesh might be replaced by a translucent coating on the glass or plastic transparent material of the door.
[0022] Cabinet 1 may be manufactured of any material. However, it is desirable to manufacture cabinet 1 of a metal to contain the RFID field inside the cabinet. Preferably, the types of metals that may be used are steel, although aluminum may also be used. The front door and sides may be transparent to allow the user to see the products inside the cabinet. The front door may include a thermal printer that can provide a paper record of the item taken out from the cabinet. Within the cabinet, it will often be preferable to use non-metal components for shelving and partitions in order to not interfere with the RFID field.
[0023] A wire mesh can be used as a shield to contain the RFID field within the cabinet while maintaining the desired level of transparency. The maximum diameter of the holes in the mesh is dictated by the frequency of the RFID field used. In the alternative, a conductive film in the pattern of a mesh may be coated on the transparent surfaces of the doors, either as a thin translucent layer or as an opaque coating. This arrangement provides the necessary containment of the RFID field within the cabinet while allowing the user to see inside the cabinet. More particularly, a regular acrylic panel, and coated a first pass in the vertical orientation with silver based conductive ink in stripes, one-half inch on center, the stripes having a width in the range of 0.05 to 0.25 inches. Then, in the horizontal direction, with carbon based conductive ink in stripes, half inch on center, the stripes having a width in the range of 0.05 to 0.25 inches. Without any specific ground connections, the resulting checkerboard pattern of vertical silver based conductive ink stripes and horizontal carbon based conductive ink stripes contains the RFID field such that the RFID tags associated with items are not read outside the cabinet, while retaining the visibility of the contents of the cabinet.
[0024] The use of effective shielding allows for the use of a single powerful energizer and receiving antenna within the cabinet. The use of a single, more powerful energizer and receiving antenna provides reliable detection and a cost effective solution relative to the prior art that use multiple energizers and antennas of shorter range in each shelf or section of a larger cabinet.
[0025] A computer controls access to the interior of the cabinet by unlocking and opening the locked front door. Typically, there will be multiple doors, and only the applicable door will be opened according to the level of access associated with the user's ID. This ID may be provided by a variety of means including an RFID badge, a personal identification number, a voice command, a biometric scan, a magnetic card, a barcode badge read or the like depending upon the particular requirements of the cabinet.
[0026] It is preferable to use a guiding light to locate the correct cabinet, door and in some cases actual location of the product. By using guiding lights, it is preferable to flash all lights on a cabinet for a few seconds, then on a door or shelves and then down to the item. Such a method is described in U.S. Pat. Nos. 5,745,366, 5,805,455, 5,805,456, 6,039,467, 6,272,394, and 6,385,505 incorporated herein by reference for all purposes.
[0027] The computer may be either embedded within the interior of the cabinet or in close proximity to the cabinet, and coupled to the cabinet by Ethernet, wireless, optical infra-red, serial cable, USB or any other data connection means. One advantage of not having the computer embedded within the interior of the cabinet is the use of general-purpose computers with varying form factors. The type, size, shape and/or configuration is unconstrained by the cabinet design. As software rapidly evolves for the cabinet control, newer versions often need a new operating system and these in turn need a new computer. By keeping the computer external, upgrading both software and computer hardware is both easy and inexpensive.
[0028] In accordance with another aspect of the present invention, the user accesses the cabinet using a user ID and password, an RFID badge, a bar code, a mag card or various biometrics such as a thumbprint, face recognition or the like. Typically, the particular ID device is located at the user login location or the computer interface. However, in some embodiments, particularly those detecting the RFID badge of a user, the identification of a user occurs at the cabinet. One method of authorization would allow the user to approach the cabinet and have the cabinet recognize the user and unlock the cabinet doors without any action by the user. Such quick recognition presents the ultimate in convenience to busy clinicians where time is a critical factor, such as physicians, and OR nurses requiring items during a case.
[0029] The user may or may not be required to select a patient identification or cost center. Instead, accounting for an item may be determined by: 1) the location of the equipment (e.g. the account number for supplies for the OR department in which the equipment is located); 2) identifying the user and associating that user with a department; 3) association to a case by way of the user and the time of day, since the case management system will usually know which users are working on which case; or 4) association to a case and/or patient by use of an identifier such as a mag card or and RFID card. The RFID cards may have a case or patient number encoded on them. Alternatively, these cards may have a permanent ID that is temporarily associated at the beginning of the day with the patient or case for that day.
[0030] There may be governmental/regulatory requirements regarding access to certain contents in the cabinets. The user access rules accommodate and authenticate any unique access requirements. For example, the user may be prompted to scan a bar code or otherwise enter information about the product or push a button assigned to a selected item. The user may enter the name(s) or an alias name(s) for a product(s) at the computer. The computer can generate a visual picture of the layout of the cabinet, highlighting where the product(s) is (are) located within the interior of the cabinet. A visual picture is useful, since, for cost reasons, there may be no lights to guide the user to a specific door.
[0031] Although the advantage of RFID is that an item removal is recorded with no action from the user, many facilities have cabinets currently in place where the removal of an item is recorded by scanning a barcode, pushing a button, or keying an item ID. There are considerable advantages in combining existing apparatus and methods with the apparatus and methods of the present invention. Existing cabinets are upgraded utilizing aspects of the present invention to accommodate RFID tags. In initial introduction, before a process is fully set up to tag and identify items, a mixed system may be needed. For cost reasons, it may be desirable to stock low cost items that are used in association with high cost items (e.g. gauze pads, tubing, gloves and the like) in the same location. While it may not be worth RFID tagging the low cost items, their use should be recorded to track inventory levels and ensure prompt re-ordering.
[0032] Depending on the user's access privileges, one or more of the doors on the cabinet unlock upon successful completion of the entry requirements at the computer user interface. It is desirable to temporarily disable the RFID reader when the door is opened so that an item removed but held near the open door is not mistakenly interpreted by the system as an unremoved item. The user then removes or returns the items from or to the opened compartments.
[0033] If the computer is remote, then a sound and/or visual sensor at the cabinet may alert the user to check the monitor of the computer after removing a product. The alert tells the user that the computer has determined that further action is needed in addition to the removal of the product, such as 1) entering of a serial number or other information into the computer; 2) reading of such information using a bar code scanner mounted at the cabinet or at the computer; or 3 ) alerting the user that an expiration date for the product may have occurred. Preferably, these “sounds” will be recorded speech to clearly instruct the user as to what is needed such as “please scan the serial number and expiration date”. In many cases, it is preferable to use text to speech since this allows information specific to the item to be included. For example, “You just removed a Cordis 78 French Catheter. Please check that this is the right item.”
[0034] A particularly useful text to speech function is to state the quantity on hand. To the degree a system can be in error, the correction of the quantity on hand ensures timely restocking and the availability of product to the caregiver at all times. For example the system might say “You just removed a Medtronic 8F Guiding Catheter. There should be three remaining. If not, please correct the inventory level.”
[0035] Another useful query is an automated speech to the user asking “Did you get what you needed? If NOT, then, please press 1—If YES, then, no response is necessary.” Such a query provides a view into the product usability and customer satisfaction.
[0036] Typically, items are placed on the shelves in fixed locations according to the identity of the product using a labeling system. The current quantity on hand for each type of item is tracked by the embedded or local PC, and may be transmitted to a central server. The system generates a restock list any time the quantities of particular items drop below a predetermined par level. Since different items may be restocked from different sources, the system needs to be able to identify different restock lists for those sources.
[0037] There may be times when the item removed from the cabinet cannot be returned to the cabinet without additional processing. For example, some regulated items may not be returned to the cabinet by the user without additional authorization and verification. Also, some items may have a limited, out-of-cabinet life and may need some verification that the item was not exposed to adverse environment.
[0038] Some authorization and verification may be local, but some may be remote. If local, then it is appropriate to use a “fill-or-kill” method where the next time a restock request is generated comparing par level with actual quantity on hand, no memory of any previous unfulfilled orders is retained. For other products, particularly those ordered outside, it is necessary to track what has been previously ordered, and subtract that from any new comparison of par level minus the current on hand order quantity, but also to net out previous orders that are delivered over time.
[0039] When an order is placed with a specific source of material, it is important that the cabinet location receives information regarding what was ordered and order identification number. Therefore, when the restock technician comes to the cabinet after receiving the item for that order, he/she can select the appropriate restock order list by entering (or bar coding or RFID scanning) the number of the restock list. This action allows the computer to register the items that have been brought and the quantities being put away. If this procedure is omitted, the restock technician must select each item in the computer and enter the quantity they are restocking.
[0040] The cabinet restock process is easy with the system of the present invention in place. The restock person simply enters their ID and adds the items to the cabinet. In an alternate approach, the user is required to identify a restock list with the associated items. In this case, when he/she adds the items to the cabinet, a shortage list may be produced. A shortage list is useful when relying on an outside fulfillment house to deliver and restock the cabinet, since this will detect diversion of product between the time it was picked in the remote warehouse and when it reached the cabinet. More particularly, since the restock person knows there will be a check, there is less temptation to divert product for one's personal consumption.
[0041] With cabinet RFID reading device set up on an Ethernet network, either directly or through a local compute controlling access to the cabinet, the material manager can connect to the reader or cabinet computer database, and get an up to the second inventory of items contained within the cabinet through the Inventory Control Module software. This can be an automated process that enables the RFID Readers to scan items in the remote cabinet and to alert the staff if any items are critically low or out of stock.
[0042] If a caregiver needs a particular item that is not stocked in the cabinet in their department, they can use the care giver software to check other RFID enabled cabinets on the network to find the item they needs and how many are actually on hand in that cabinet, all in real time.
[0043] With access to the cabinet information derived in real time through the RFID reader, or the computer database supporting the RFID reader, the materials manager can scan the RFID cabinets for items that are past their expiration date or items that are in a lot that has been recalled so they can be collected for return to the manufacturer. It is particularly important to get this information in real time, since items may have been taken then subsequently returned etc, and in previous systems the associated information (lot # serial number) had to be tracked at each step. Using RFID, you essentially have instant inventory review—fresh instantaneous reading of exactly what is in each location, not a deduction of what is in each location as a result of manual recordings of takes, returns, etc., which over time can be incorrect if any step in the recording process is missed.
[0044] FIG. 3 illustrates another cabinet having RF shielding on its outer walls and doors. | An RFID for cabinet for monitoring items having an RFID tag includes a cabinet having at least one locking front door. An RFID detector is used for monitoring each item placed within the cabinet and is located within the interior of the cabinet. A computer is coupled to the RFID cabinet and controls opening and closing of the front door and is configured to receive an input that identifies the user. In this way, the computer is configured to periodically record data read from the RFID tags by the RFID detector. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of German Application No. 100 23 011.3 filed May. 11, 2000, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a device which forms an integral part of a carding machine and which processes fiber material, particularly cotton, chemical fibers or the like. The carding machine includes a main carding cylinder followed by a doffer and a pull-off (withdrawing) device for the fiber material.
[0003] In a known apparatus, as disclosed, for example, in German Offenlegungsschrift (application published without examination) No. 23 64 262, two doffers are provided which take the fiber material off the main carding cylinder. The two doffers are disposed with respect to the carding cylinder and with respect to one another in such a manner that each doffer cooperates with both the carding cylinder and with the other, adjacent doffer and further, a web stripping device cooperates with one of the doffers. The two doffers rotate in opposite directions with respect to the main carding cylinder. An increased production rate is intended by the provision of the two doffers and their arrangement with respect to the carding cylinder and to one another. It is a condition of such a prior art arrangement that the carding cylinder process a fiber quantity which is approximately twice the usual amount handled by a carding cylinder. For such an increased fiber amount the cylinder clothing must be coarser to increase its processing capacity. This disadvantageously reduces the carding quality to a significant extent.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide an improved fiber processing device of the above-outlined type from which the discussed disadvantages are eliminated and with which a fiber web of increased specific weight may be obtained without adversely affecting the carding quality.
[0005] This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the carding machine includes a main carding cylinder and a doffer to which fiber material is transferred from the main carding cylinder and a fiber removing device positioned downstream of the doffer as viewed in an advancing direction of the fiber material through the carding machine. A gathering device including at least one gathering roll is disposed downstream of the doffer for effecting a negative draft on the fiber material between the doffer and the gathering roll.
[0006] The fiber gathering device, including at least one fiber gathering (fiber accumulating) roll, results in a negative draft of the fiber material: The gathering rolls accumulate and densify the fiber material, whereby an increased specific weight (quantity per surface or length) of the fiber web is obtained. The fiber web or sliver of increased specific weight is advantageously adapted for further processing, for example, into articles of hygiene.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a schematic side elevational view of a travelling flats-type carding machine including a gathering device according to the invention.
[0008] [0008]FIG. 2 is a schematic side elevational view of a gathering roll disposed between a doffer and a stripping roll.
[0009] [0009]FIG. 3 is a schematic view of two gathering rolls with rpm-controlled drives.
[0010] [0010]FIG. 4 is a schematic side elevational view of a sliver draw unit following a sliver forming device.
[0011] [0011]FIG. 5 is a schematic side elevational view of a calender assembly following a sliver forming device.
[0012] [0012]FIG. 6 shows two crushing rolls and a transverse fiber web pull-off device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] [0013]FIG. 1 shows a carding machine CM which may be a high-performance DK 903 model manufactured by Trüftzschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roll 1 , a feed table 2 cooperating with the feed roll 1 , licker-ins 3 a , 3 b , 3 c , a main carding cylinder 4 , a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guiding element 9 , a sliver trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 having slowly circulating flat bars 14 (whose speed is between 0.05 and 0.4 m/min) and stationary carding elements 15 a , 15 b . The doffer 5 is rotated by a symbolically shown drive 5 a . The directions of rotation of the rolls are shown by curved arrows drawn therein. The width of the rolls is between 1 and 1.5 m. The fiber processing direction, that is, the travel direction of the fiber material through the carding machine is indicated at A, while B designates the sliver discharged by the calender rolls 11 , 12 . The carding machine CM serves particularly for the processing of cotton and/or chemical fibers.
[0014] The carding machine CM may be supplied with fiber material by an upstream-connected fiber feeder 30 which may be a DIRECTFEED DFK model, manufactured by Trützschler GmbH & Co. KG.
[0015] According to the invention two gathering rolls 18 and 19 are disposed between the doffer 5 and the stripping roll 6 . The first gathering roll 18 cooperates upstream with the doffer 5 and downstream with the second gathering roll 19 . The doffer 5 and the second gathering roll 19 rotate co-directionally, while the first gathering roll 18 rotates in the opposite direction. The circumferential speed of the first gathering roll 18 is less than that of the doffer 5 , whereas the circumferential speed of the second gathering roll 19 is less than that of the first gathering roll 18 . In this manner the fiber material is slowed down and accumulated. The circumferential speed of the doffer 5 may be, for example, 5 m/sec and that of the stripping roll 6 may be 8 m/sec. The circumferential speed of the first and second gathering rolls 18 and 19 may be, for example, 125 m/min and, respectively, 105 m/min at the most. The exit speed of the weight-enhanced sliver B discharged by the calender rolls 11 , 12 may be approximately 20 m/min or more. Also referring to FIG. 2, the clothing teeth 5 b of the doffer 5 are oriented rearwardly with respect to its direction of rotation 5 a . The clothing teeth 6 b of the stripping roll 6 are essentially radially oriented. The clothing teeth 18 b of the first gathering roll 18 are oriented rearwardly relative to its rotary direction 18 a whereas the clothing teeth of the second gathering roll 19 are oriented rearwardly with respect to its direction of rotation. By virtue of the gathering device 17 according to the invention, comprising the two gathering rolls 18 and 19 illustrated in FIG. 1, a negative draft, that is, an accumulation of the fiber material is effected at the first gathering roll 18 with respect to the doffer 5 in a ratio of approximately 1:3 to 1:5 and at the second gathering roll 19 with respect to the doffer 5 in a ratio of approximately 1:3 to 1:6. In this manner a heavy sliver B may be made, having a sliver weight of, for example, 80-150 g/m.
[0016] As shown in FIG. 2, between the doffer 5 and the stripping roll 6 a single gathering roll 18 is provided which cooperates with the doffer 5 and the stripping roll 6 .
[0017] As shown in FIG. 3, the gathering rolls 18 and 19 are driven by respective rpm-regulated motors 24 and 25 which may be a.c. servomotors and which are coupled to an electronic control and regulating device 26 . Such a control system may set the negative draft (accumulation) of the fiber material to the desired extent.
[0018] As shown in FIG. 4, the calender rolls 11 , 12 at the output of the carding machine are followed by a regulated draw unit 20 with which irregularities in the sliver B may be evened, particularly as concerns sliver thickness and structure. The intake roll pair 20 a and the mid roll pair 20 b are driven by an rpm-regulated electric motor 21 and the output roll pair 20 c is driven by an rpm-regulated electric motor 22 . The motors 21 and 22 are connected to an electronic control and regulating device 23 .
[0019] Turning to FIG. 5, the calender rolls 11 , 12 of the carding machine are followed by a reinforcing device 27 having two calender rolls 27 a and 27 b which serve for reinforcing the fiber web or the sliver B by pressure or profiling. By virtue of this arrangement structural changes are compensated for which may appear in the course of the gathering process and at the same time, the fiber web or sliver B is improved for further processing. The reinforcing device 27 is followed by a processing device 29 which may be an automatic apparatus for making sanitary napkins. To achieve a high output speed and output quantity, advantageously the speed of the sliver B exiting the carding machine and the speed of the sliver C entering the after-connected processing machine 29 are adapted to one another. In such a case no intermediate storage arrangement for the sliver is required. The adaptation is effected by a non-illustrated electronic control and regulating device which is connected with the rpm-regulated drive motors of the carding machine and the processing machine 29 .
[0020] It is noted that in a carding machine for practicing the invention instead of the traveling flats assembly 13 exclusively stationary carding elements, and instead of the fiber web guiding elements 9 a transverse fiber web pull-off unit 31 as shown in FIG. 6 may be used.
[0021] In case an intermediate storage arrangement is required, the sliver B may be deposited in a non-illustrated coiler can.
[0022] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A carding machine includes a main carding cylinder and a doffer to which fiber material is transferred from the main carding cylinder and a fiber removing device positioned downstream of the doffer as viewed in an advancing direction of the fiber material through the carding machine. A gathering device including at least one gathering roll is disposed downstream of the doffer for effecting a negative draft on the fiber material between the doffer and the gathering roll. | 3 |
This application is a division, of application Ser. No. 08/284,667, filed Aug. 19, 1994, which is a continuation-in-part of application Ser. No. 08/053,863 filed Apr. 29, 1993, now abandoned, which is a CIP of Ser. No. 07/903,580, filed Jun. 25, 1992, which is a continuation-in-part of application application Ser. No. 07/824,161, filed Jan. 22, 1992 now abandoned, which is a continuation-in-part of application Ser. No. 07/727,245, filed Jul. 11, 1991 now abandoned.
The present invention relates to the prevention and treatment of Lyme disease in mammals and in particular to immunogenic formulations comprising different serological forms of OspC to retard or prevent the development of Lyme disease. The invention also comprises recombinant methods for the preparation of novel antigens.
BACKGROUND OF THE INVENTION
Lyme disease or Lyme borreliosis are terms used to describe the diverse clinical symptoms associated with tick-borne spirochetal infections caused by Lyme Disease Borrelia. Common manifestations of Lyme disease include disorders affecting the skin [erythema migrans (EM) or acrodermatitis chronica atrophicans (ACA)], nervous system (neuro-borreliosis), and joints (arthritis) but other organs and tissues may become infected and diseased. Lyme disease has a world-wide distribution and is the most prevalent tick-borne disease in both the United States and Europe. The range of clinical symptoms commonly associated with Lyme disease in Europe is broader than that in the United States, with skin and nervous system disorders being common in Europe but rare in the United States, whereas arthritis is more common in the United States than in Europe. The clinical symptoms in North America appear to be a subset of those observed in Europe.
Lyme disease is typically treated with antibiotics. Treatment may be delayed, however, due to the often complex clinical picture and the lack of widely available, reliable diagnostic tests. If the disease is allowed to proceed to a chronic condition, treatment with antibiotics is more difficult and is not always successful. Furthermore the prospect that permanent damage is induced is likely to be increased during the course of a prolonged infection. Accordingly, a vaccine to prevent Lyme disease is desirable.
Two antigens from Lyme disease Borrelia have been described that can protect against infection/disease by this organism as determined in animal models of Lyme disease. These antigens, OspA and OspC (or “pC”), therefore are likely candidates for inclusion in any vaccine designed to protect against Lyme disease. See Simon et al., European patent No. 418,827; Fikrig et al., Science 250: 553-56 (1990); Preac-Mursic et al., Infection 20: 342-49 (1992). OspA and OspC share many characteristics. Both are lipoproteins that are exposed at the cell-surface, (Howe et al., Science 227: 645-46 (1985); Bergstrom et al. Mol. Microbiol. 3: 479-486 (1989)), both are plasmid-encoded (Barbour et al., Science 237: 409-11 (1987); Marconi et al., J. Bacteriol. 175: 926-32 (1993)), the genes for these proteins are present in most strains (Barbour et al., J. Infect. Dis. 152: 478-84 (1985); Marconi et al., J. Bacteriol. 175: 926-32 (1993)), and both exist in multiple serologically distinct forms (Wilske et al., (1989)).
The existence of multiple, serologically distinct forms of these antigens is an obstacle to the development of an OspA and/or OspC vaccine to protect against most, if not all, forms of Lyme disease. For instance, it has been demonstrated by Fikrig et al., J. Immun. 148: 2256-60 (1992), that immunization with one serological form of OspA, such as recombinant OspA of strain N40, need not protect against a challenge with a strain expressing a different OspA, for example, strain 25015. Consequently, it is necessary to develop typing schemes to classify and group the different variants of the antigen i.e., OspA and/or OspC) such that the optimal mixture of serologically distinct forms of the antigen(s) that are needed to give broad protection can be determined.
A serotyping system for OspA has been developed using a limited number of monoclonal antibodies as the typing tools and 7 serotypes of OspA have been described using this methodology. Wilske et al., Ann. N.Y. Acad. sci. 539: 126-43 (1988). Restriction fragment length polymorphism (RFLP) analysis of OspA genes from 55 different European and North American strains identified six distinct genogroups. Wallich et al., Infection and Immunity 60: 4856-66 (1992). OspA proteins from North American isolates seem to be reasonably uniform since twelve of fourteen OspA's belonged to OspA type I and two to OspA type III. By contrast, the OspA's from European isolates are much more heterogeneous and include representatives of OspA types I (18), II (17), IV (4) and V (1). Construction of a phylogenetic tree based on sequence data for twelve OspA proteins from individual strains of B. burgdorferi supports the findings of the RFLP analysis but sequence information from isolates from two of the six genogroups is still lacking. At present no typing system exists for OspC.
Another consideration when selecting the appropriate antigens for inclusion in a vaccine is whether they are derived from strains that are epidemiologically important for the disease. In the mid-1970's it was postulated that pathogenic bacteria arise from a limited number of clones of highly related bacteria that in some way have a selective advantage in causing disease. This clonal hypothesis has since been confirmed. See Achtman et al., J. Infect. Dis. 165: 53-68 (1992). Thus, it is highly likely that among the numerous strains of Lyme disease Borrelia found in nature, only a limited number of “clones” exist that are highly adapted to causing mammalian, and in particular human, disease. In developing a vaccine to protect against disease in mammals and hence also in humans, it is of paramount importance to identify disease associated clones so that efforts can be concentrated against them. Thus it is necessary to elucidate the population structure of the species Lyme disease Borrelia and identify disease associated clones.
To date, a number of methods have been used to resolve the population structure of Lyme disease Borrelia, including (A) RFLP analysis of genomic DNA or of specific genes (LeFebvre et al., J. Clin. Micriobiol. 27: 636-39 (1989); Marconi & Garon, J. Bacteriol 174: 241-44 (1992); Postic et al., Res. Micriobiol. 141: 465-75 (1990); Stahlhammar-Carlemalm et al., Zbl. Bak 274: 28-39 (1990); Adam et al., Infect. Immun. 549: 2579-85 (1991); Wallich et al., Infect. Immun. 60: 4856-66 (1992)), (B) DNA-DNA hybridization (LeFebvre et al., J. Clin. Micriobiol. 27: 636-39 (1989); Postic et al., Res. Micriobiol. 141: 465-75 (1990)), (C) analysis of 16S rRNA by hybridization to oligonucleotide probes (Marconi et al., J. Clin. Micriobiol 30: 628-32 (1992) or by sequencing (Adam et al., Infect. Immun. 59: 2579-85 (1991); Marconi & Garon, J. Bacteriol. 174: 241-44 (1992)), (D) fingerprinting by an arbitrarily primed polymerase chain reaction (Welsh et al., Int. J. System. Bacteriol. 42: 370-77 (1992)), (E) multi-locus enzyme electrophoresis (Boerlin et al., Infect. Immun. 60: 1677-83 (1992)) and (F) serotyping of isolates (Peter & Bretz, Zbl. Baktk. 277: 28-33 (1992)).
There is broad agreement between the results obtained by these different procedures. In general, it appears that Lyme disease Borrelia isolates can be divided into at least three major groups. Indeed, some investigators believe that the genetic distances between members of these groups is sufficient to merit differentiating them into three separate species: B.burgdorferi sensu stricto (type strain B31), B.garinii sp. nov. (type strain 20047) and a species designated B.afzelii or the “group VS461 Borrelia.” See Baranton et al., Int. J. Syst. Bacteriol. 42: 378-383, 1992; Marconi & Garon, supra.
The significance of the existence of these different groups for vaccine development remains to be fully elucidated. It is clear from the data of Wallich et al., Infection & Immunity 60: 4856-66 (1992), that there is a strong association between the genogroup to which an isolate belongs and the type of OspA that is produced: isolates from the group containing strain B31 (genogroup AAA or B.burgdorferi sensu stricto) produce a type I OspA (all of thirty strains analyzed), isolates from the group containing strain 20047 (genogroup BBB or B.garinii sp. nov.) usually produce a type II (17/19) OspA but types V (1/19) and VI (3/39) were also noted, isolates from the clone containing strain BO23 (genogroup BBA or group VS 461) produce a type IV OspA (4/4), the remaining two isolates (genogroup B, B/A, A) produce a type III OspA.
Lyme disease isolates from North America predominantly belong to one group (genogroup AAA or B.burgdorferi sensu stricto), represented by strain B31, and consequently produce a type I OspA. This suggests that a vaccine containing a type I OspA may be sufficient to protect against most isolates causing Lyme disease in North America at the present time. In Europe the picture is more complex, since all three major clones are found and there is correspondingly an increased diversity in the types of OspA present (genotypes I, II, IV, V, VI). Furthermore, OspA was found not to protect in two studies, conducted using Lyme disease isolates from Europe, which also demonstrated the utility of OspC as a protective antigen. See U.S. patent application Ser. No. 07/903,580; Preac-Mursic et al., Infection 20: 342-49 (1992).
It was not known heretofore whether OspC was clonally inherited, with specific types of OspC restricted to particular groups of Lyme disease isolates (that is, to B.burgdorferi sensu stricto, B.garinii sp. nov. or group VS461). As OspC is plasmid encoded, Marconi et al., J. Bacteriol. 175: 926-32 (1993), it was conceivable that there had been plasmid-mediated transfer of the OspC gene between the different species of Lyme disease isolates. If this were the case, then the different types of OspC which are known to exist but which have not been defined, would not necessarily be clonally inherited.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide an effective OspC vaccine, with broad cross protective levels in relation to all strains, against Lyme disease in mammals, by selecting OspC formulations based on defined OspC families resolved by phenotypic typing (the OspC “serovar” typing) and RFLP typing analyses, and sequence analysis of a large variety of strains of worldwide origin.
Furthermore, the OspC gene has been discovered to be clonally inherited. Consequently, it now is possible to interpret the results of the OspC typing schemes in view of epidemiological information from a “Common Membrane Antigen Typing” (CMAT) scheme, described below, which can be used to elucidate the clonal population structure of Lyme disease Borrelia strains. By the same token, it also now is possible to select the most appropriate OspC vaccine formulations either (a) to enable one to design vaccines to protect against strains prevalent within defined geographical regions or (b) to protect specifically and preferentially against epidemiological important disease associated clones or clonal clusters of B. burgdorferi.
In accomplishing these and other objectives, there has been provided, in accordance with one aspect of the present invention, an immunogenic composition comprising
(a) an amount of material comprising (i) one or more OspC antigens of Lyme disease Borrelia substantially purified from each of the 20 currently recognized OspC families of FIG. 11 or (ii) OspC variants or OspC mimetics of said OspC antigens, said OspC variants or OspC mimetics having a structure that is sufficiently similar to native OspC to induce the production of protective antibodies; and
(b) a physiologically-acceptable excipient therefore, wherein said amount is sufficient to elicit, in a mammal susceptible to Lyme borreliosis, an immune response that is protective against Lyme borreliosis.
According to a further embodiment, the above immunogenic composition comprises one or more, preferably two or more, OspC antigens of Lyme disease Borrelia of the 20 currently recognized OspC-families of FIG. 11 or OspC variants or OspC mimetics of said antigens as defined above under (ii), and a physiologically-acceptable excipient as defined above under (b).
In accordance with another aspect of the present invention, an immunogenic composition is provided that comprises an amount of material comprising (i) one or more OspC antigens of Lyme disease Borrelia substantially purified from each of the OspC-families of FIG. 19 expressed by the human disease associated (HDA) clones and clonal clusters or (ii) OspC variants or OspC mimetics of the OspC antigens, said OspC variants or OspC mimetics having a structure that is sufficiently similar to native OspC to induce the production of protective antibodies; and
(b) a physiologically-acceptable excipient therefore, wherein said amount is sufficient to elicit, in a mammal susceptible to Lyme borreliosis, an immune response that is protective against Lyme borreliosis.
As a preferred embodiment, the above immunogenic composition comprises one or more, preferably two or more, OspC antigens of the ospC-families of FIG. 19, or OspC variants or OspC mimetics as defined above under (ii), and a physiologically-acceptable excipient as defined above under (b).
In a preferred embodiment, an immunogenic composition within the present invention is designed to protect against Lyme disease Borrelia strains prevalent within a particular geographic region, such as North America, Europe or Austria. As a preferred embodiment a combined OspA/OspC vaccine, which is superior to a vaccine formulated with either antigen alone is claimed.
The invention also comprises recombinant methods for the production of novel OspC antigens together with DNA sequences, expression vectors, and transformed host cells.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a - 1 d describes 77 Borrelia strains which were used in the experimental investigations. The country of origin and the biological source (i.e., human, tick or animal) from which these strains were isolated is described. The clinical material and disease syndrome from which the human isolates were obtained is shown, too (Abbreviations: CSF, cerebrospinal fluid; ACA, acrodermatitis chronica atrophicans; EM, erythema migrans). The properties of 5 additional stains not experimentally studied are also included, since published information pertaining to these strains was used in some of the analysis.
FIG. 2 lists the addresses of all strain contributors.
FIG. 3 lists the monoclonal antibodies and the common membrane antigen specificities. The homologous reacting strain and the isotype of the monoclonal antibody are also indicated.
FIG. 4 shows the individual scores and representative strains for each of the CMATs resolved by the CMAT typing scheme.
FIG. 5 shows the dendrogram of the cluster analysis performed on the CMAT typing data. The frequency of occurrence of the CMATs among the strains tested also is indicated, as are the grouping of the individual CMATs into CMAT clusters (all CMATs with >50% similarity) and CMAT subgroups (all CMATs with >20% similarity).
FIG. 6 gives the reaction pattern of a panel of 13 OspC-specific monoclonal antibodies with the various serovar type strains.
FIG. 7 shows the sizes of the restriction fragments obtained when PCR amplified ospC genes (prepared as described in example 4 are digested with the enzymes Dpn11, Dde1 and Dra1. The data presented shows the 35 unique patterns of restriction fragments (i.e. 35 ospC RFLP types) identified from an analysis of the restriction fragment data from the 82 strains listed in Type strains chosen to represent each of the ospC RFLP types are also given.
FIGS. 8-1 through 8 - 12 show aligned, partial nucleotide sequences of twenty-four ospc genes selected from strains belonging to ospC RFLP types 1-24. (SEQ ID NOS 3, 53, 7, 9, 11, 13, 15, 17, 19, 21, 23 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, and 49 are partially shown in this Figure.)
FIGS. 8 a - 1 through 8 a - 12 show the complete sequences of the novel ospC genes according to FIGS. 8-1 through 8 - 12 including the 3′ end. Additionally, FIGS. 8 a - 1 through 8 a - 12 include the sequences for the ospC genes of strains H13 and 28691. (SEQ ID NOS 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 49, 41, 43, 45, 47, 49 and 51 are shown in this Figure.)
FIGS. 9-1 through 9 - 3 show the aligned, partial amino acid sequences deduced from the nucleotide sequence data of FIGS. 8-1 through 8 - 12 . The sequenced region corresponds to the first 92% of the mature OspC protein. (SEQ ID NOS 4, 54, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 38, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, and 50 are partially shown in this Figure.)
FIGS. 9 a - 1 through 9 a - 3 show the complete amino acid sequences of the novel OspC antigens according to FIGS. 9-1 through 9 - 3 including the C-terminal. Additionally, FIGS. 9 a - 1 through 9 a - 3 include the sequences for the OspC antigens of strains H13 and 28691. (SEQ ID NOS 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50 and 52 are in this Figure.)
FIG. 10 is a dendrogram of the OspC protein sequence data of FIGS. 9 a - 1 through 9 a - 3 showing the phylogenetic relationships between the sequences and the degree of sequence identity. This analysis has been used to assign the OspC proteins into OspC families. Members of an OspC family comprise related OspC sequences with >8% sequence identity. It is also shown that OspC proteins cluster in a species-specific manner indicating that the OspC protein is clonally inherited.
FIG. 11 lists the 20 OspC families and indicates strains chosen as a representative of that family.
FIGS. 12 a - 12 d summarize the results of the CMAT and OspC typing analyses of the 82 strains from FIG. 1 . The data are sorted by OspC family and RFLP-type to show the frequency with which strains belonging to a particular OspC family occur. Strains which have not been assigned an OspC family are designated 99. The biological and geographical origins of the strains are included to allow a comparison of these parameters with the OspC family. CMAT values have been assigned to 5 strains for which there was a published description but which were not tested (i.e., strains of B.burgdorferi, B. afzelii and B. garinii correspond to CMATs 1, 3, and 4, respectively). OspC serovars have not been assigned to all strains; 5 strains were not available (NA), others were not tested (NT) since they expressed insufficient.
FIG. 13 lists the sequences (SEQ ID NOS: 67-72, 78, 68, 73-74, 76, 75, and 74, respectively) of the mapped OspC epitopes together with the frequency of their occurrence among the strains analyzed. At the bottom of the table the monoclonals are grouped into categories according to the frequency with which they react with the seventy seven strains in the study.
FIG. 14 shows the map of the generalized OspC protein marking the location of the epitopes of numerous BBM monoclonal antibodies indicated by their numbers.
FIG. 15 shows the results of active immunization experiments using the gerbil model. Groups of animals were immunized with purified OspC protein variants of either the same (H7) or different OspC family (ZS7, PKO and W) to that of the challenge strain Orth. The results indicate that there is strong cross protection when one immunizes with a variant of the same family as that expressed by the challenge strain, but that there is little or no protection when one immunized with an OspC variant of a different OspC family to that of the challenge strain.
FIG. 16 summarizes the OspC typing information and the distribution of human isolates among the various OspC types. The specificity and prevalence of OspC antibodies present in human Lyme disease sera form the Czech Republic is also shown. OspC antibody specificity was defined by testing against a panel of 18 different Borrelia strains representing 16 OspC families.
FIG. 17 shows the yeast expression vector pPC-PP4 with the OspC coding sequence under transcriptional control of the methanol inducible AOX-1 promotor.
FIG. 18 shows the results of active immunization experiments using the gerbil model. Animals were immunized with purified OspC protein derived from B. burgdorferi strain Orth and recombinantly produced from P. pastoris GS115/pPC-PP-4. The results indicate a strong protection with the Borrelia derived as well as with the Yeast-derived OspC protein.
FIG. 19 shows examples of OspC vaccine formulations designed to protect against specific human disease associated clones or clonal clusters of Lyme disease Borrelia.
DETAILED DESCRIPTION OF THE INVENTION
By the serovar, restriction fragment length polymorphism (RFLP) and sequencing analyses described in greater detail below, it has been discovered that, despite the high degree of OspC protein heterogeneity across different Lyme disease isolates, OspC proteins can be grouped into a limited number of families on the basis of similarity in amino acid sequence, inter alia. In accordance with the present invention, the implications of this finding are realized in the design of vaccine formulations that provide a high level of cross-protectivity, relative to different strains, which has not been attained previously.
In order to achieve cross-protection, one must be able to predict the effectiveness of the components of a given vaccine in protecting against all possible disease-causing strains. Pursuant to the present invention, this problem is overcome by inesuring that the heterogeneity of protective antigen components in a vaccine optimally reflects the heterogeneity found in nature. In particular, for the OsC protein, this is achieved by formulating vaccines that contain representatives for all of the OspC families revealed by the sequence analysis described here. An example of such a formulation entails including in a vaccine the twenty OspC proteins that are representative of all of the aforementioned OspC families. An OspC family is defined as a group of OspC proteins that have more than 80% amino acid sequence identity over the first 92% of the mature OspC protein, i.e., excluding the information for the 18 a leader sequence and the final 16 aa as shown in FIGS. 9-1 through 9 - 3 , 9 a - 1 through 9 a - 9 a 3 , and 10 .
The present invention thus relates in one aspect to an immunogenic composition comprising one or more OspC antigens substantially purified from each of the twenty OspC families which the present inventors have delineated for the first time. The use of twenty antigens, for example, is an improvement over the prospect of including all possible OspC variants found in nature (cf. 35 OspC RFLP types described here). In accordance with another aspect of the present invention, the formulation of a Lyme disease vaccine is simplified further by restricting the number of antigenic components, in a manner that does not reduce the protective efficacy of the vaccine, by the combined application of OspC typing data and epidemiological data. Exemplary of this approach, as described in greater detail below, are (A) the design of vaccine formulations for use in a particular geographic region, such as North America, Europe or a particular country such as Austria, and (B) the design of a vaccine that is targeted to protect specifically against only those clones, identified by CMAT analysis, which are associated with human disease. In one embodiment under rubric (A), a vaccine is formulated for use in North America and contains antigens representing only those OspC families observed for American strains, namely, families 2 and 3 (see FIG. 12 ).
According to another embodiment said vaccine formulated for use in North America comprises strains from families 2, 3, 18 and 20.
In order to identify clones of Lyme disease Borrelia, a population structure analysis was carried out by CMAT analysis. A “CMAT (type)” is defined as a unique, nine-digit score resulting from the combined score of molecular weight variants of nine common membrane antigens detected, and in some cases differentially discerned, by a given set of monoclonal antibodies specific for these antigens. A “CMAT cluster” is a group of related CMAT (types) having at least 50% similarity in their CMAT score. A “CMAT group” is used here to denote a group of CMAT types having more than or equal to 20% similarity in their CMAT score. Consequently, a CMAT group may be comprised of several CMAT clusters which in turn may be comprised of several CMAT types.
A “clone” is defined as a CMAT type comprising more than one strain, or otherwise, a clone is a group of strains having the same CMAT type and thus are considered as arising from a common ancestral strain. A “clonal cluster” is a group of clones related at the CMAT cluster level (that is, where their CMAT types are more than 50% similar). A “human disease-associated clone” is a clone that, based on epidemiological and clinical data, can be shown to be associated frequently with human disease. Likewise, a “human disease-associated clonal cluster” is a clonal cluster that can be shown, from epidemiological and clinical data, to be associated frequently with human disease. Thus in an embodiment under rubric B (see above), an OspC vaccine is formulated against the human disease associated CMAT clones 1.2.4., 3.2.13, and the clonal cluster 4.2.17, 4.2.18, 4.2.20 and 4.2.22.
OspC is known to be a suitable immunogen for eliciting a protective immune response in animal models of Lyme disease when the challenge organism is the same Lyme disease isolate from which the OspC was derived. Due to the serological heterogeneity of OspC proteins among Lyme disease Borrelia strains, however, it was thought that immunization with OspC from one strain might not protect against infection with a wide range of Lyme disease Borrelia isolates and recognized a need to validate this assumption based upon cross-protection studies (Example 6). Based upon these studies, it became clear that an OspC based vaccine would have to contain several serologically distinct forms of OspC. A prerequisite to the formulation of such a multivalent OspC vaccine is knowledge of the degree of diversity among the different forms of OspC and of how these different forms are related. Accordingly, such information is applied, pursuant to the present invention, in the development of new vaccine formulations against Lyme disease Borrelia.
The first step towards acquiring the required information was the development of a monoclonal antibody based typing system (Example 1) for characterizing the OspC proteins from different Lyme disease Borrelia strains. In order to ensure that the widest range of OspC proteins would be analyzed a large number of Lyme disease Borrelia strains (i.e. 62 of the 82 strains depicted in FIG. 1 were selected as producing sufficient Ospc to allow a reliable characterization) from different geographical locations and isolated from humans (for example, skin, cerebrospinal fluid and blood), animal and ticks were studied. Another key aspect of this analysis was the use of a large number of OspC-specific monoclonal antibodies (25 in the present example) that had been produced not simply to one OspC protein but to six different ospC proteins, thereby increasing the diversity of OspC epitopes capable of being recognized and hence increasing the power to discriminate between different OspC proteins. The data collected in this analysis clearly showed that a large degree of serological heterogeneity exists among the OspC proteins from different sources. Examples of the reaction patterns of the 16 distinct types, or serovars, of OspC that were identified with a collection of 13 monoclonal antibodies are shown in FIG. 6 . In addition, 12 strains were non-typable as they did not react with any of the monoclonal antibodies.
Although highly effective, the typing of OspC by serological means was nevertheless incomplete, since it requires both that OspC is expressed as a major protein and that a set of antibodies with a wide range of specificities is available. It was clear from the results of the serovar analysis that the full-spectrum of antigenic diversity was not being detected with the monoclonal antibodies being used, even although they had been chosen to minimize this problem. Consequently, the heterogeneity of OspC was further studied by analysing the restriction fragment length polymorphism (RFLP) occurring within the ospC gene (Example 3). An analysis of the data from 82 strains (i.e. experimental data from all 77 strains in our culture collection plus information deduced from 5 published ospC sequences; see FIG. 1) revealed the presence of 35 distinct RFLP ospC types. Although this method detects more variation than evident from the serovar typing, there is extremely good agreement between the results obtained with the two methods (FIG. 12 ).
The classification of Borrelia strains into serovars and RFLP-types according to the OspC protein or gene that they possess, made it possible, pursuant to the present invention, to select for more detailed characterization a limited number of OspC variants which are representative of the population as a whole. Thus, a panel of 29 strains comprising one or more representatives from each of the most ubiquitious OspC types was selected, the OspC gene was amplified by PCR, and the nucleotide and deduced amino acid sequence determined (see Example 4). The amino acid sequence of the mature OspC protein (from cysteine 19; see U.S. patent application Ser. No. 07/903,580, previously incorporated by reference), less the last 16 amino acids, was used to determine the relationship between OspC proteins from the different OspC serovars /RFLP-types.
The relationship between closely related OspC proteins from the same OspC type was investigated as a further check on the validity of the typing systems and to establish whether within a given OspC type there was further heterogeneity. The nucleotide and deduced amino acid sequences for the OspC proteins from 24 strains are shown in FIGS. 8-1 through 9 a - 3 , respectively (i.e., 22 sequences from this study and 2 published sequences for strains 2591 and PBI). The dendrogram showing the phylogenetic relationship between the OspC protein is presented in FIG. 10 .
An OspC antigen-based immunogen of the present invention can comprise a mixture of different serological forms of naturally occurring OspC protein. In another embodiment of the invention, the immunogenic composition comprises OspC variants or OspC mimetics of OspC antigens. Thus, in addition to OspC protein obtained from Lyme disease Borrelia cells, as described hereinafter, recombinant OspC variants of the naturally-occurring molecule (“OspC variants”) and “mimetics” compounds having mimotopes which mimic ospC epitopes can be employed.
The category of OspC variants includes, for example, oligopeptides and polypeptides corresponding to immunogenic portions of the OspC molecule and any non-proteinaceous immunogenic portions of the OspC molecule. Thus, a variant is intended to include a polypeptide that is homologous to and retains the salient immunological features of the natural OspC molecule. In this regard, “homology” between two sequences connotes a likeness short of identity indicative of a derivation of the first sequence from the second. For example, a polypeptide is “homologous” to OspC if it contains an amino acid sequence which corresponds to an epitope recognized by OspC specific antibodies or T-cells. Such a sequence may be only a few amino acids long and may be a linear determinant or one which arises when amino acids from separated portions of a linear sequence are spatially juxtaposed after protein folding or after being subjected to covalent bond modification. The amino acid sequences which are antigenic determinants for purposes of this invention can be ascertained, for example, by monoclonal mapping analysis techniques which are known in the art. See Regenmortel, Immunology Today 10: 266-72 (1989), and Berzofsky et al., Immunological Reviews 98: 9-52 (1987). For instance, in the the present invention, the OspC antigen comprises one or more of the following amino acid sequence (SEQ ID NOS 67-76) (FIG. 13 ):
(1) VKLSESVASLSKAA;
(2) TDNDSKEAILKTNGT;
(3) KELTSPVVAETPKKP;
(4) FVLAVKEVETL;
(5) YAISTLITEKLKAL;
(6) PNLTEISKKITDSNA;
(7) ASANSVKELTSPVV;
(8) SPVVAETPKKP;
(9) GKKIQQNNGLGA; and
(10) SPVVAESPKK
or variants or mimetics of the above epitope sequences. In the preferred embodiment, the vaccine would comprise peptides corresponding to serotype-specific epitopes selected from one or more of the OspC proteins from the OspC families described herein. Cross-protection studies (Example 6) indicate that protective immunity is induced by serotype-specific epitopes. An example of a serotype-specific epitope is sequence #2 from strain Orth (see above), which is recognized by monoclonal antibodies BBM38 and BBM39 which are specific for OspC proteins from OspC family 5 (serovar 4). This epitope corresponds to the putative epitope (DNDSKE amino acids 2-7 of SEQ ID NO 68) predicted from a hydrophilicity analysis of the Orth OspC. Potential serotype-specific epitopes can likewise be predicted to occur between amino acid residues 120-155 (starting from the first cysteine residue) in OspC proteins from other OspC families (example 4). Such a vaccine may include variants or mimetics of the peptide sequences, as described below. Assaying for this type of similarity can also be effected via a competitive-inhibition study in the case of antibodies or by T-cell proliferation.
Polypeptides which qualify as OspC variants according to these criteria can be produced, pursuant to the present invention, by conventional reverse genetic techniques, i.e., by designing a genetic sequence based upon an amino acid sequence or by conventional genetic splicing techniques. For example, OspC variants can be produced by techniques which involve site-directed mutagenesis or oligonucleotide-directed mutagenesis. See, for example, “Mutagenesis of Cloned DNA,” in CURRENT PROTOCOLS IN MOLECULAR BIOLOGY 8.0. 3 et seq. (Ausubel et al. eds. 1989) (“Ausubel”).
Other OspC variants within the present invention are molecules that correspond to a portion of OspC, or that comprise a portion of OspC but are not coincident with the natural molecule, and that display the immunogenic activity of OspC when presented alone or, alternatively, when linked to a carrier. An OspC variant of this sort could represent an actual fragment of the natural molecule or could be a polypeptide synthesized de novo or recombinantly.
To be used in recombinant expression of OspC or an OspC variant, a polynucleotide molecule encoding such a molecule would preferably comprise a nucleotide sequence, corresponding to the desired amino acid sequence, that is optimized for the host of choice in terms of codon usage, initiation of translation, and expression of commercially useful amounts of OspC or a desired OspC variant. Also, the vector selected for transforming the chosen host organism with such a polynucleotide molecule should allow for efficient maintenance and transcription of the sequence encoding the polypeptide. The encoding polynucleotide molecule may code for a chimeric protein; that is, it can have a nucleotide sequence encoding an immunological portion of the OspC molecule operably linked to a coding sequence for a non-OspC moiety, such as a signal peptide for the host cell.
In order to isolate a DNA segment which encodes an OspC molecule, total Lyme disease Borrelia DNA can be prepared, according to published methods. see, for example, Maniatis, et al., MOLECULAR CLONING: A LABORATORY MANUAL (Cold Spring Harbor Laboratories, NY 1982); Baess, Acta Pathol. Microbial. Scand. (Sect. B) 82: 780-84 (1974). The DNA thus obtained can be partially digested with a restriction enzyme to provide a more or less random assortment of genomic fragments; an enzyme with a tetranucleotide recognition site, such as Sau3A (MboI), is suitable for this purpose. The fragments from such a partial digestion then can be size-fractionated, for example, by sucrose gradient centrifugation (see Maniatis, supra) or by pulsed field gel electrophoresis, see Anal, Trends in Genetics (November 1986), at pages 278-83, to provide fragments of a length commensurate with that of DNA encoding the OspC molecule.
According to well-known methods described, for example, in Ausubel at 5.0.1 et seq., the selected fragments can be cloned into a suitable cloning vector. A DNA thus obtained could be inserted, for example, at the BamHI site of the pUC18 cloning vector. Chimeric plasmids or phage, inter alia, produced by joining the size-selected fragments to the cloning vector can then be transformed into E. coli or other host cells, which are screened thereafter for expression of the encoded protein. A variety of methods can be used for screening libraries to identify a clone containing the OspC gene. These methods include screening with a hybridization probe specific for OspC, such as an oligonucleotide probe, or screening for OspC antigen expression using a OspC specific immunological reagent. The latter, for instance, may be accomplished by immunoblotting a library with anti-OspC monoclonal antibodies or with a specific polyclonal antibody prepared from animals immunized with purified OspC. Once a clone containing OspC encoding DNA is identified in the library, the DNA can be isolated, the region encoding OspC protein fully characterized (as by sequencing), and, subsequently, the DNA can be used to produce OspC expression vectors suitable to the production of OspC-active protein.
As noted previously, to provide an effective immunogen the structure of the recombinantly expressed pC protein should be sufficiently similar to that of native (non-denatured) OspC so that the protein induces the production of protective antibodies. To this end, it is preferable to express OspC-encoding DNA in such a way that intracellular proteolysis and aggregation of the expression product, in denatured form, are avoided. One way to avoid these problems is to recombinantly produce pC in a host-vector system that provides for secretion of pC from the host cell, preferably directly into the culture medium. One such system is provided by Bacillus subtilis. A suitable secretion vector can be constructed for B. subtilis by linking the B. amyloliguefaciens α-amylase signal sequence, see Young, et al., Nucleic Acid Res. 11: 237-49 (1983), to the Bacillus plasmid vector pUB110, as described by Ulmanen, et al., J. Bacteriol. 162: 176-82 (1985). According to this approach, the coding sequence for the foreign protein is cloned downstream of the promoter, the ribosome binding site and the signal sequence for α-amylase. Transcription and translation of OspC is under control of the α-amylase promoter and translation machinery in this construct, and secretion of pC from the host cell is provided by the α-amylase signal sequence. The present invention comprises expression vectors which are functional in procaryotes as well as eucaryotes. Similar vectors for use in yeast have been described and the expression secretion of OspC in yeast using these vectors could be achieved. A suitable expression vector can be constructed by linking the OspC coding sequence to an inducible promotor in a yeast replication plasmid. According to this approach, the coding sequence of the foreign protein is cloned downstream of e.g. the AOX-1 promotor and transcription and translation can be induced by the addition of methanol to the culture medium. Either intracellular expression or secretion of the foreign protein (by linking a signal sequence to the coding sequence of the mature protein) can be obtained. A preferred yeast strain is Pichia pastoris. In yeast, especially P. pastoris, high yields of the expression products were obtained.
Yet another approach for expressing OspC in a host vector-system which avoids proteolysis, aggregation and denaturation is the use of vaccinia virus as a vector capable of expression in a variety of mammalian host cells susceptible to vaccinia infection. This approach would entail preparing a recombinant vaccinia virus-derived vector in which the pC gene is placed under the control of a promoter, along with translation and secretion signals, suitable for expressing OspC protein in a vaccinia-infected host. As described in U.S. Pat. No. 4,603,112, the contents of which are hereby incorporated by reference, the plasmid also would comprise, 5′ to the transcription control regions and 3′ to the 3′ termination and polyadenylation signals, flanking sequences which are conducive to homologous recombination into a wild-type vaccinia genome. When a construct of this sort is introduced into a vaccinia infected host cell, the flanking sequences direct recombination between the plasmid vector and the vaccinia virus, with the result that a cloned structural sequence (here, encoding OspC) becomes part of, propagates with and is expressed with the vaccinia virus. Preferably, the region between the flanking sequences also contains a selectable marker, such that in the presence of selection medium only those cells containing recombined vaccinia virus (and, in the present context, the sequence encoding a OspC-active polypeptide), will survive.
A recombinant vaccinia strain produced in this manner can be used to infect mammalian cells, such as Vero cells or CV1 cells, suitable for high density fermentative growth. The OspC-active protein expressed in these cells during fermentation would be secreted into the fermentation medium, from which it would be purified via conventional methodology.
In addition to natural OspC and OspC variants, the present invention comprehends compounds (“mimetics”) which mimic OspC epitopes (“mimotopes”). One example of a mimetic is an anti-idiotype antibody, that is, an antibody that is produced by immunizing an animal with an antibody which specifically binds to an epitope on an antigen. The anti-idiotype antibody recognizes and conforms to the combining site on the first antibody. Therefore, the shape of its combining site closely resembles the epitope which fits into the combining site of the first antibody. Because an anti-idiotype antibody has a combining site whose shape mimics the original antigen, it can be used as a vaccine to generate antibodies which react with the original antigen. See Fineberg & Ertl, CRC Critical Reviews in Immunology 7: 269-84 (1987). Appropriate mimetics could be identified by screening with a OspC antibody to detect which compounds bind thereto or could be produced by molecular modelling. See Morgan et al., “Approaches to the Discovery of Non-Peptide Ligands for Peptide Receptors and Peptidases,” in ANNUAL REPORTS IN MEDICINAL CHEMISTRY (Academic Press 1989), at pages 243 et seq.
The vaccine of the present invention is intended for the immunization of a susceptible mammal, including a human being, against Lyme disease. The term “immunogen” means an antigen which evokes a specific immune response leading to humoral or cell-mediated immunity, in this context, to infection with Borrelia. “Immunity” thus denotes the ability of the individual to resist or overcome infection more easily when compared to individuals not immunized, or to tolerate the infection without being clinically affected.
The immunogen of the present invention may be further comprised of an acceptable physiological carrier. Such carriers are well-known in the art and include macromolecular carriers. Examples of suitable carriers in mammals include tuberculin PPD, bovine serum albumin, ovalbumin or keyhole limpet hemocyanin. The carrier should preferably be non-toxic and non-allergenic.
The immunogen may be further comprised of an adjuvant such as an aluminum compound, water and vegetable or mineral oil emulsions (for example, Freund's adjuvant), liposomes, ISCOM (immunostimulating complex), water-soluble glasses, polyanions (such as poly A:U, dextran sulphate or lentinan), non-toxic lipopolysaccharide analogues, muramyl dipeptide, and immunomodulating substances (for example, interleukins 1 and 2) or combinations thereof. The preferred adjuvant is aluminum hydroxide. Immunogenicity can also be enhanced in mammals which have received live attenuated bacterial vectors, such as Salmonella or Mycobacteria, or viral vectors like vaccinia, which express an OspC-active polypeptide.
Techniques for formulating such immunogens are well-known in the art. For instance, the immunogen of the present invention may be lyophilized for subsequent rehydration in a physiologically acceptable excipient such as saline or other physiological solution. In any event, the vaccine of the present invention is prepared by mixing an immunologically effective amount of OspC with the excipient in an amount resulting in the desired concentration of the immunogenically effective component of the vaccine. The amount of immunogenically effective component in the vaccine will depend on the mammal to be immunized, with consideration given to the age and weight of the subject as well as the immunogenicity of the immunogenic component present in the vaccine. In most cases, an amount of the immunogenic component of the vaccine will be in the range of 1 to 100 micrograms per antigen per dose, and preferably will be in the range of 10 to 50 micrograms per antigen per dose.
In yet another embodiment of the present invention, the immunogenic composition is comprised of one or more OspC antigens or OspC variants or OspC mimetics or the OspC antigens substantially purified from each of the OspC-families of FIG. 11 expressed by the human disease associated clones and clonal clusters, as described in Example 1.
Thus, the invention comprises according to claims 1-3 immunogenic compositions of OspC antigens of Lyme disease Borrelia consisting either or one or more, preferably two or more, OspC antigens of the 20 currently recognized OspC-families as shown in FIG. 11 or of one or more OspC antigens from each of the 20 currently recognized OspC-families of FIG. 11 . Instead of the above OspC antigens, the combination may comprise OspC variants or OspC mimetics of said OspC antigens, said OspC variants or OspC mimetics having a structure that is sufficiently similar to native OspC to induce the protection of protective antibodies.
FIG. 13 shows the sequences of essential epitopes. According to the invention, OspC antigens are included which comprise one or more of such epitopes. Consequently, these antigens or polypeptides according to the invention comprise at least the epitopic sequence as shown in FIG. 13 . This epitopic sequence may be as short as the amino acid sequence given in brackets in FIG. 13 .
As a further embodiment the invention also comprises immunogenic compositions which contain either one or more, preferably two or more, OspC antigens of the OspC-families of FIG. 19 or one or more OspC antigens from each of the OspC-families of FIG. 19 . These immunogenic compositions correspond to patent claims 4-6.
In another embodiment, the immunogenic composition is formulated to protect against Lyme disease Borrelia strains prevalent within a particular geographic region. Thus, in one embodiment, a vaccine is formulated which is preferentially protective against Lyme disease Borrelia strains most prevalent in North America. In another embodiment, a vaccine is formulated for Lyme disease Borrelia strains most prevalent in Europe. In a third embodiment, a vaccine is formulated for Lyme disease Borrelia strains most prevalent in Austria. Vaccine formulations for each of these geographical locations are shown in Example 7. In addition, to OspC vaccine formulations a combined OspA/OspC vaccine is considered since this could be superior to a vaccine formulated with either antigen alone;
firstly, because Lyme disease Borrelia strains may not always express one or the other of these antigens but they always express either OspA or OspC;
secondly, it has been reported that there is reciprocal regulation of these two antigens such that if the expression of one is down regulated (e.g. in response to the immune response) the expression of the other is enhanced.
thirdly, at least for in vitro studies with OspA it has been demonstrated that vaccine escape mutants could arise, a problem that can be circumvented by the inclusion of a second antigen since a double mutational event in two independent antigens is extremely improbable.
fourthly, the immune response of vaccinees to a given antigen is not uniform. The inclusion of two antigens enhances the probability that an individual, who responds poorly to either OspA or OspC, would nevertheless be protected by making a protective response to the other antigen.
Finally, it is to be expected that there could be a synergetic effect and that a more solid immunity would be obtained with a vaccine comprising OspA and OspC.
In one embodiment one or more OspC proteins from the OspC families 1-20 would be combined with one or more OspA proteins as expressed by Borrelia strains B31, Orth, H4 and KL11.
In another embodiment a combined OspA/OspC vaccine for the United States comprises an OspC from OpsCs family 2 and 3 together with an OspA as expresssed by strains B31. In a further embodiment a combined OspA/OspC vaccine for use in Europe comprises 14 OspCs from OspC families 2, 4-7, 9, 10, 12, 13 and 14, 15-17, 19 together with OspAs as expressed by strains B31, Orth, H4 and KL11. A further embodiment of a combined OspA/OspC vaccine for Austria comprises OspCs from families 2, 4-7, 10, 13 and 19.
The invention also comprises the use of a combination of antigens as comprised by the above-described immunogenic compositions for the manufacture of a vaccine for the treatment or prevention of Lyme borreliosis in a mammal. As a preferred embodiment this vaccine is useful for humans.
The methods for preparing of vaccines according to the present invention are designed to ensure that the identity and immunological effectiveness of the specific molecules are maintained and that no unwanted microbial contaminants are introduced. The final products are distributed and maintained under aseptic conditions. The method of immunizing a mammal against Lyme disease involves administering to the mammal an effective amount of the foregoing immunogen. Administration may involve any procedure well-known in the art. For instance, a suitable administration strategy may involve administering the above described vaccine to mammals which are known to be exposed to ticks bearing Lyme disease Borrelia, approximately 6 months to 1 year prior to the time of anticipated exposure. Any immunization route which may be contemplated or shown to produce an appropriate immune response can be employed, in accordance with the present invention, although parenteral administration is preferred. Suitable administration forms include subcutaneous, intracutaneous or intramuscular injections or preparations suitable for oral, nasal or rectal administration.
By “substantially purified” is meant a homogenous protein free of any toxic components, thereby reducing the likelihood of an adverse reaction. “Homogenous” in this context means that at least 80% (w/v) of the protein is fully intact OspC, with nearly all of the remainder represented by OspC breakdown products. Thus, impurities in the form of media constituents and other Borrelia proteins are present, if at all, only in trace amounts. Homogenous OspC may be comprised of more than one serological form of OspC.
In this way the present invention enables the removal of unwanted, potentially immunogenic proteins which could induce autoantibodies and cause harmful autoimmune reactions in the immunized mammal. By the same token, the above-described purification method also ensures lot-to-lot reproducibility during vaccine production.
The preferred method of purification comprises the following steps:
(a) disruption of Lyme disease Borrelia cells and fractionation by centrifugation into “membrane” and “cytoplasmic” components;
(b) extraction of the membrane fraction with a non-denaturing detergent followed by centrifugation to obtain a supernatant comprising solubilized protein and to remove insoluble material as a pellet; and
(c) fractionation of solubilized antigens by ion-exchange chromatography (diethylaminoethyl or “DEAE”), adsorbed antigens being eluted with a NaCl gradient.
The purification method can include concentration and further purification of the antigens by:
(a) hydroxylapatite chromatography, adsorbed antigens being eluted by increasing the phosphate content of the buffer; and/or
(b) immobilized metal-affinity chromatography, adsorbed antigens being eluted with imidazole.
Other elution methods known in the art include elution by a reduction in pH or by increasing concentrations of ammonium chloride, histidine or other substance with affinity for the chelated metal.
Cell disruption can be accomplished by lysing cells by shaking them in suspension in a cell mill with tiny glass beads, by sonication or in a French-press. Alternatively, antigens may be extracted directly from the cell-surface of the organism by exposing the cell to a detergent, by changing the ionic strength of the cell's environment or by slightly shifting the temperature. Alternatively, a starting material comprised of membrane blebs which are shed from cells may be used.
The extraction of the membrane fraction may be accomplished with a detergent which preferably has good solubilizing power, is non-denaturing and is compatible with ion-exchange chromatography. The preferred detergent is zwitterionic detergent 3-14 by Calbiochem, although any detergent or organic solvent may be used which has the above characteristics. The detergent is typically used at a concentration of 1% (w/v) but would be effective to varying degrees in the range of 0.01-10% (w/v). Detergent extraction is carried out at a temperature in the range of 0 to 60° C., preferably at 37° C. and should take from ten minutes to 8 hours, preferably one hour. Chaotropic agents such as urea could be used in addition to the detergent to improve the solubilization process.
The detergent solubilized antigens are then fractionated by DEAE-chromatography. Preferably, a DEAE ion-exchange resin is used but other anionic or cationic exchange resins may be used instead or in conjunction with one another. In accordance with the present invention, an ion-exchange resin comprises an insoluble matrix to which charged groups have been coupled. Functional groups used for anion exchangers include amino ethyl (AE), diethylaminoethyl (DEAE) and quaternary aminoethyl (QAE) groups. Cation-exchangers may have carboxymethyl (CM), phospho- or sulphopropyl (SP) groups. Although samples are applied to the column in a Tris buffer containing zwitterionic detergent 3-14 (1%) and the antigens are eluted with a gradient of NaCl, other formulations may be equally effective.
Antigens may be concentrated by binding them onto hydroxylapatite, according to methods well known in the art. An alternative or complementary procedure by which antigens can be further concentrated/purified is by immobilized metal-affinity chromatography. This latter method is preferred to hydroxylapatite chromatography for the purification of OspC since a better separation from OspA and OspB is achieved.
The advantage of the above described non-denaturing purification process is that the three-dimensional conformation of the protein is maintained, thereby keeping all the antibody combining sites found on the native protein, including those involved in protection. If a protein is denatured, the binding sites may be partially or completely destroyed and the capacity of the antigen to induce antibodies to the antigenic sites will be correspondingly diminished. Proteins thus altered therefore would be undesirable for use in vaccines.
Further, the invention comprises the recombinant preparation of novel OspC antigens as shown in FIGS. 9 a - 1 through 9 a - 3 . The invention also includes novel DNA sequences encoding OspC antigens according to FIGS. 9 a - 1 through 9 a - 3 . These DNA sequences are shown in FIGS. 8 a - 1 through 8 a - 12 . Also comprised by the invention are those DNA sequences which have at least 80% homology to any of the sequences of FIGS. 8 a - 1 through 8 a - 12 .
The invention also comprises the recombinant expression. vectors in procaryotic or eucaryotic host cells, especially expression vectors useful in yeast, preferably Pichia. pastoris. According to a preferred embodiment of the invention the expression vector is inducible by methanol.
The invention comprises novel OspC anigens as (i) encoded by any of the sequences according to FIGS. 8 a - 1 through 8 a - 12 or (ii) having a homology of at least 80% with any of the amino acid sequences of FIGS. 9 a - 1 through 9 a - 3 .
The present invention is described in more detail in the following examples, which are illustrative and in no way intended to limit the scope of the invention.
EXAMPLE 1
CMAT Typing of Borrelia burgdorferi Strains and Cluster Analysis of the Results which Thereby Permits the Elucidation of CMAT Clusters, CMAT families, “Human Disease Associated” Clones and Clonal Clusters
Seventy Seven strains (see FIG. 1) were obtained from numerous sources listed in FIG. 2 . Care was taken that the collection contained strains of widely differing geographical origin and from as many differing epidemiological and clinical situations as possible.
Membrane Fractions were Then Prepared from All Strains as Follows
Lyme disease Borrelia cells were harvested by centrifugation (7000×g, 20 minutes, 4° C.), the cell pellet was washed twice in PBS containing 5 mM MgCl 2 and the cell wet-weight was determined. The washed cells were then lysed by shaking the mixture in a Vibrogen cell-mill (Model V14, Buhler). Three minute cycles of shaking with cooling (4° C.) were repeated until lysis was greater than 99% complete, as assessed by dark-field microscopy. The lysate was then filtered on a sintered glass filter to remove the glass beads and the retained beads were washed with buffer to improve the yield of bacterial antigens in the filtrate. The lysate was centrifuged for 20 minutes at 7500×g at 4° C. to produce a crude membrane fraction termed membrane 2 or the “lsp” (low speed pellet) fraction. The supernatant was further centrifuged for 30 minutes at 100,000×g at 4° C. to produce a more purified membrane fraction, termed membrane 1 or “hsp” (high speed pellet). Both membrane fractions were washed twice in 100 mM Tris-HCL buffer pH=7.4, using the original centrifugation conditions. The membrane 2 fraction was used for typing purposes whereas the membrane 1 fractions were reserved for antigen purification.
Membrane proteins present in the membrane 2 fractions of each strain were then analyzed by SDS-PAGE, as described in Laemmli, U. K., Nature (London) 227: 680-85 (1970). Variations in molecular weight were determined by reference to the electrophoretic mobility of a set of standard proteins covering the molecular weight range of the full spectrum of membrane antigen markers used in the analysis.
The antigens are transferred to a nitrocellulose filter and are identified using a panel of monoclonal antibodies, for example, by immunoblotting methods well known in the art. Ausubel, et al., 2 CURRENT PROTOCOLS IN MOLECULAR BIOLOGY 10.8.1 et seq. (1992). Monoclonal antibodies are produced by well-known hybridoma technology, Kohler and Millstein, Nature 256: 495-97 (1975) . In the preferred embodiment of the present invention, the strains set forth in FIG. 1 are analyzed. In general, the selection of a membrane antigen for inclusion in the analysis is governed by (a) the availability of monoclonal antibodies to detect it and to distinguish it from the numerous other antigens present in the SDS-PAGE membrane antigen profiles of bacterial strains; (b) by the antigen in question being present in a significant proportion of the strains analyzed i.e. a common antigen; (c) by the fact that it can be reproducibly detected in multiple, separately prepared, membrane fractions of the same strain, i.e., there is no evidence for intra-strain variation for the particular antigen in question; (d) by the fact that the antigen marker is stably expressed in the same isolate after multiple cultivation and passage and after storage for considerable time (up to 2 years) ; and (e) by lack of evidence by published scientific literature that the genes encoding the markers are extrachromosomally inherited or that variations of the antigens were under specific antigen variation mechanisms which can lead to intra-strain variation.
FIG. 3 indicates the monoclonal antibodies used to identify the 9 common membrane antigens used in the analysis (E90, E60, E59, E43, Fla, E29, E22 antigens, the E18+E20 antigen combined and the E10 antigen). The antigens are scored according to ascending molecular weight and, in the case where more than one monoclonal antibody exists, by their slightly differing reactivity (for example, E60 and E43), according to the reaction pattern of the antigen with those monoclonal antibodies.
FIG. 4 lists all unique combinations of 9 scores found for the strains analyzed which are represented as a 9-digit number. This 9-digit number then is designated as the common membrane antigen type (CMAT) of that strain. A cluster analysis was then performed to establish the relationship between all the CMATs observed. This was performed by determining the genetic diversity of each antigen and establishing an unweighted dissimilarity matrix calculated from the data of all unique CMATs. Absence of an individual common antigen score was treated as if it were missing data. The matrix formed was then subjected to cluster analysis with linkage by a weighted pair group method using arithmetic averages (Sneath and Sokal, supra) on an IBM compatible personal computer running CSS Statistica Statsoft software.
The resulting dendrogram of the cluster analysis is shown in FIG. 5 . In general, the dendrogram indicates that the Lyme disease Borrelia population is indeed well structured. By plotting the Eigen values at which each of the clustering steps occurs, it is possible to choose the most appropriate level at which to segregate the bacteria into categories.
The most ideal position to make divisions occurs at points in the curve where there are major jumps in the Eigen values for successive clustering steps. As shown in the dendrogram of FIG. 5, this occurs at a level where there is between 68% and 88% difference in CMAT scores. This division divides the population into four major groups termed CMAT groups. A second major jump in the Eigen values for successive clustering occurs between the 40% and 52% difference between CMAT scores. This segregation divides each CMAT group into two to three clusters of individual CMATs. For convenience the 80% difference between scores was taken as the level at which CMAT grouping occurs, and 50% difference in scores at the level at which CMAT clustering occurs.
From the foregoing, it is apparent that the population of B. burgdorferi can be divided into four major CMAT groups, each of which is composed of two to three CMAT clusters. Each CMAT cluster was itself composed of between one and five individual CMATs. Comparison of these results with those of other population structure analysis taxinomic studies (Marconi & Garon, J. Bacteriol 174: 241-44 (1992) ; Boerlin et al., Infect. Immun. 60: 1677-83 (1992) Baranton et al., Int. J. Syst. Bacteriol. 42: 378-383, (1992)) indicates that the CMAT group 1 corresponds to the genospecies Borrelia bugdorferi sensu stricto, that CMAT group 3 is equivalent to Borrelia afzelii also known as “group VS461” and that CMAT groups 2 and 4 correspond to B. garinii sp. nov. The reason why the CMAT analysis divided the B. garinii genospecies into 2 CMAT groups is unclear but it may be due to the fact that fewer markers were used than for example in the multi locus isoenzyme electrophoresis study (Boerlin et al., Infect. Immun. 60: 1677-83 (1992)).
When looking at the occurrences of particular strains within each CMAT (FIG. 5) it is apparent that 7 CMATs have more than one representative and thus can be considered as clones, i.e. strains having a common ancestry. Indeed 67% of all strains fell just within three distinct CMAT clones, for example, CMAT 4 (Clone 1:2:4) comprised 12 strains, CMAT 13 (Clone 3:2:13) comprising 23 strains, and CMAT 18 (Clone 4:2:18) with 15 strains. Notably, 76% (31 of 41, ) of the human isolates analyzed were found to be distributed among these three major clones. Furthermore, if one considers CMATs 17, 18, 20 and 22 together as part of a related clonal cluster, all belong to CMAT cluster 4.2, then the human disease associated goes up to a 87%. Due to this strong association with human disease, they can be considered as “human disease associated” (HDA) clones or clonal clusters (see definitions above) . If one further looks at the types of isolates found among these three major clones, it becomes evident that CMAT 13, for example, appears to be associated with the chronic skin syndrome ACA (5 strains ) and that in general this clone is associated with syndromes of the skin (17 out of 19). In contrast, the other two HDA clones seem to be more prevalent in disseminating disease, that is, they are isolated form the blood or CSF from patients suffering from neuroborreliosis or Lyme arthritis. In the case of CMAT cluster 4.2 (i.e.CMATs 17,18,20 and 22) the epidemiological data seems to suggest a strong association with Neuroborreliosis. Of the 10 human isolates 6 were isolated from CSF material or from Neuroborreliosis patients, and four were isolated from patients with ECM, a syndrome normally associated with acute disease which can also be associated with neuroborreliosis. The syndrome association of CMAT 4 strains is not quite so clear cut as 2 of human isolates were isolated from blood, 3 from CSF and 1 from a patient with EM.
A further analysis of epidemiological data pertaining to the various strains reveals that the three major clones or clonal clusters have distinctive geographic distributions, and that this feature in turn correlates with general differences in the primary syndrome of Lyme disease observed within these regions. For example, CMAT 4 is the most predominant CMAT observed in North America, an area of the world where arthritic syndromes predominate. CMAT 13 and CMAT 18 are found predominantly in North Central Europe, where neurological syndromes and chronic skin syndromes predominate. Of the 3 major clones, only CMAT 4 is found in both North America and Europe (France, Austria and Russia), being widely distributed on both continents. Interestingly in areas of Central Europe, in particular Austria and Switzerland, where Lyme disease is endemic, all 3 major human disease associated clones co-exist.
The realization that human disease is predominantly caused by just one clone (CMAT 4) in CMAT group 1 ( Borrelia bugdorferi sensu stricto) and one clone (CMAT 18) of CMAT group 3 ( Borrelia afzelii ) and a clonal cluster (CMAT cluster 4.2) in CMAT group 4 ( B. garinii sp. nov.; allows one, in accordance with the present invention, to focus on these clones/clonal clusters with the aim of designing vaccines, such as an OspC vaccine or a combined OspC/OspA vaccine, which specifically protects against them. This vaccine then could be used in geographical regions where these clones are extremely prevalent. Furthermore, because of the differing clinical syndromes associated with the differing clones, one can target a vaccine against these clones and, hence, in effect design vaccines to protect against specific syndromes.
EXAMPLE 2
Development of an OspC Serovar Typing Scheme to Analyse the Serological Variation of the OspC Antigen of Lyme Disease Borrelia
Preparation of Anti-OspC Antibodies
A panel of 25 monoclonal antibodies was produced against (a) four purified OspC proteins derived from (1) the Austrian strain Orth (BBM 34-39); (2) the German strain PKO (BBM 42-45); (3) the Czechoslovakian strains E61 (BBM 46, 47, and 49) and (4) KL10 (BBM 40-41); (b) an OspC protein enriched cocktail of antigens derived from the Austrian strain W (BBM 22, 24, 25, 27, 28, and 29); and (c) a membrane 2 fraction of the Czech strain M57(BBM 75-77).
The anti-OspC protein specificity of various monoclonal antibodies were confirmed by surfblot analysis against a membrane fraction of strain W or M57 in the case of BBM22, 24, 25, 27-29, and BBM 75-77, respectively, and in the case of the others by line blot analysis against the appropriate purified protein.
Membrane ELISA Method
Serotyping of the ospc proteins was performed using a standard membrane ELISA technique. Membrane 2 fractions of all strains, prepared as describe in Example 1, were diluted to 0.1 mg/ml in phosphate buffered saline (PBS) pH 7.4 dispensed into individual wells of microtiter plates. The plates were allowed to dry out overnight at 37° C. Prior to use, the plates were washed twice in PBS, and then 50 ml of the diluted antibody solution in PBS containing 1%. human albumin were added to each well and the plates incubated for one hour at 37° C. The plates were washed four times before the addition of the anti-mouse IgG alkaline phosphates conjugated antibody. The plates were incubated at 37° C. for another hour before being washed four times prior to the addition of substrate, in order to estimate the amount of bound antibody.
Initially all strains were tested against all 25 monoclonal antibodies in order to see which monoclonals were most appropriate for serotyping purposes. Attempts were made to establish uniform positive and negative test criteria, however it became clear that this was not possible due to the vastly different levels of expresssion of the Osp C antigens within differing strains. To overcome this problem membrane 2 fractions were analysed be Western blot method, transfered to nitrocellulose and stained using Aurogold. Those strains which expressed no or low amounts of Osp C proteins (15 strains in all), as judged by the absence of a major protein in the 22 to 28 Kd molecular weight range, were removed from the study. Despite this, in a number of cases (for example, when using BBM 28, 29, 37 43, and 45), there was still no readily observed distinction between positive and negative results and thus these monoclonal antibodies were deemed unsuitable for typing purposes. All these antibodies recognise common epitopes and are thus of little discrimatory value anyway. Based on the strain coverage data of the initial analysis, a number of monoclonal antibodies were also found to recognise similar epitopes, e.g. BBM 24, 25 and 27, BBM 38 and 39 and BBM 75, 76, and 77, and thus only only one from each group (BBM 24, BBM 39 and BBM 77, respectively) were used in the final serovar typing scheme. By removing these strains and monoclonal antibodies it was then possible to establish the criteria of a positive reaction as being one in which the optical density value obtained was significantly (three times) higher than the background level of negative strains. In practice this meant that a positve result had an Optical Density (OD) value greater than 0.6. All positive reactions were also confirmed by western blot analysis of the same membrane preparations. As a result of the western blot analysis it was discovered that BBM 48 strongly cross-reacted with a protein of approximately 60 kilodaltons, and gave rise to numerous false positive results in the ELISA analysis. Thus BBM 48 it was also omitted from the serovar analysis. Consequently the serovar analysis was somewhat simplified using only 13 of the inital 25 anti-OspC antibodies available.
The reaction pattern of each strain with the complete panel of 13 monoclonal antibodies then was collated, and each unique pattern designated as a “serovar” (see FIG. 6 ). In the collection of 62 strains ultimately analyzed, 16 unique serovars were observed, thereby demonstrating the enormous degree of serological heterogeneity displayed by this membrane protein. The number of positive reactions observed among individual serovars ranged from between 1 to 7.
The full listing of serovar found for each strain is presented in FIG. 12 . As can be seen 12 strains (19% of the strains analysed) did not react with any of the panel of 13 monocloal antibodies (denoted by “NR” non-reactive) and were deemed non-typable. Taken together with the strains that were ommitted because of lack of or low level of expression (15 strains), a total of 22% of the strains available could not be typed. The frequency of occurrence of the serovars among the 78% of strains that could be unequivicably typed varied considerably. Only single representatives of serovars 6, 8 and 9 were observed whereas 10 strains were of serovar 2, the most common serovar. There were strong correlations between the family and genotype of the osp C protein and its serovar. Indeed in most cases there seemed to be a one to one relationship e.g for families 1, 2, 4, 5, 7, 9, 10, 14, and 15. Families 3, 12, 13, 17, 18 and 19 could either not be tested or were non typable using the monoclonal antibodies currently available. Families 6, 8 and 11 could be further subdivided serologically into 2 or 3 serovars, however it is interesting to note that the genotypes of these families also showed some diversity. One serovar (serovar 16) was observed in more that one family (families 16 and 20). This might have occurred because there are only two positive reactions in this serovar and thus the current monoclonal antibodies were not able to discriminate between the two families.
EXAMPLE 3
Restriction Fragment Length Polymorphism (RFLP) Analysis of ospC Heterogeneity
The ospC gene from strain Orth was cloned and the nucleotide sequence determined as previously described (U.S. application Ser. No. 07/903,580). Oligonucleotides corresponding to the proximal (coding strand, ATG AAAAAGAATACATTAAGTGC (SEQ ID NO:55), start codon underlined) and distal (non-coding strand, TAA TTA AGGTTTTTTTGGAGTTTCTG (SEQ ID NO:56), stop codon underlined) ends of the ospC gene from strain Orth were then used in the polymerase chain reaction (see example 4) to amplify the ospC genes from 77 strains in our culture collection. All strains tested, including 14 strains from the United States, yielded PCR fragments of the predicted size (627-642bp) indicating that the plasmid-encoded ospC gene is not only stably maintained but is much more prevalent than previously supposed. The failure to detect the OspC antigen in in vitro grown cultures is unlikely to be due to the absence of the ospC gene but rather to the absence or low level of antigen being expressed.
The polymorphism among ospC genes from different strains was determined by analysis of the restriction fragment patterns obtained after digestion of the PCR amplified ospC gene (prepared as described above) with the restriction enzymes Dpn11, Dde1 and Dra1. An analysis of the data from the 82 strains (i.e. experimental data from all 77 strains in our culture collection plus information deduced from 5 published ospc sequences; see FIG. 1) revealed the presence of 35 distinct RFLP ospC types. The number and sizes of the fragments experimentally determined using standard procedures, was confirmed in many instances by sequencing i.e. for at least one representative of RFLP types 1-23, type 24 is based on the sequence data of Padula et al. The RFLP patterns associated with each RFLP type are shown in FIG. 7 . Where available, the fragment sizes deduced from sequence information has been presented (RFLP types 1-24) in preference to the measured values. A complete listing of the RFLP-types for each strain analysed is given in FIG. 12 ).
EXAMPLE 4
PCR Amplification and Nucleotide Sequencing of Different Alleles of the ospC Gene and Cluster Analysis of the Deduced Amino Acid Sequences
As described in Examples 1 and 2, and summarized in FIG. 12, it was possible to classify Borrelia strains into OspC serovars and ospC RFLP-types. Strains representing ospC RFLP-types 1-17 and 19-23 were selected, the ospC gene was amplified by the polymerase chain reaction and the nucleotide and deduced amino acid sequence determined. In several cases, the relationship between closely related OspC proteins was investigated as a further check on the validity of the typing systems and to check for further undetected heterogeneity within OspC types. A total of 27 ospC genes were PCR amplified and sequenced as described below. The sequence information has been used to classify OspC proteins into OspC families.
Materials and Methods
A frozen Borrelia stock cell-suspension was thawed and 2 μl (5×10 6 -1×10 8 cells/ml) was centrifuged for 5 minutes at top speed in a Heraeus Biofuge A microfuge. The cell pellet was resuspended in 10 μl of 1× TAQ-buffer (Boehringer Mannheim), overlaid with 50 μl mineral oil (Pharmacia), then incubated in a boiling water bath for 8 minutes and placed immediately on ice. To the cell-lysate was added 90 μl of a reagent mixture [9 μl 10× Taq polymerase buffer, Boehringer Mannheim; 2 μl 10 mM dNTP solution, Boehringer Mannheim; 5 μl primer 1 (ATGAAAAAGAATACATTAAGTGCG) (SEQ ID NO: 57), 10 mM stock; 5 μl primer 2 (ATTAAGGTTTTTTTGGAGTTTCTG) (SEQ ID NO: 58), 10 mM stock; 0,5 μl 5,000 U/ml Taq polymerase, Boehringer Mannheim; and 68.5 μl H 2 O]. DNA amplification was performed in a LKB Thermocycler (95° C. for 36 seconds, 53° C. for 60 seconds, 70° C. for 84 seconds, 30 cycles). Amplification was monitored by analyzing 5 μl of the product on a 1% (w/v) agarose gel in Tris-Acetate buffer (40 mM Tris acetate, 2 mM EDTA, pH 8.0), staining with ethidium bromide and visualization under UV light. Amplified products were concentrated using Spin Bind microcentrifugation cartridges (FMC). DNA then was collected in 30 μl H 2 O and recovery was monitored by running 2 μl of the purified product on an agarose gel as described above.
Amplified DNA fragments (2-7 μl) were prepared for sequencing on a LKB Thermocycler (25 cycles at 95° C. for 36 seconds, 53° C. for 30 seconds, 70° C. for 80 seconds) using the Auto Cycle Sequencing kit (Pharmacia) with the fluorescein labeled primers 5′-ATGAAAAAGAATACATTAAGTGCG-3′ (SEQ ID NO: 59) and 5′-ATTAAGGTTTTTTTGGAGTTTCTG-3′ (SEQ ID NO: 60). Samples were electrophoresed on a 6% polyacrylamide sequencing gel using an automated laser fluorescent [ALF] sequencing apparatus (Pharmacia LKB) as specified by the manufacturer. The nucleotide sequence data files from the ALF were collated and analyzed using the software package DNASIS and the deduced protein sequences with PROSIS (Pharmacia-LKB).
The amino acid sequences for the OspC proteins from 24 different strains of the Lyme disease spirochetes (i.e. 22 sequences from this study and 2 published sequences for strains 2591 and PBI) were aligned by the fast/approximate method of Wilbur and Lipman, PNAS USA 80: 726-30 (1983), and the similarity scores thus generated were used to construct a dendrogram by the UPGMA method (a form of cluster analysis) of Sneath and Sokal, supra. These analyses were performed using the software package Clustal V (Higgins and Sharp, CABIOS 5: 151-53 (1989); Higgins et al., CABIOS (1991).
Results and Discussion
The aligned, nucleotide and deduced partial amino acid sequences for the ospc genes, and proteins from 24 strains, representing 24 different RFLP-types, are shown in FIGS. 8-1 through 9 a - 3 . Since the amino acids preceding the first cysteine residue (amino acid 19 in the Orth sequence) in the OspC protein are the leader sequence and not present in the mature protein (the sequence FISC is a putative signal peptidase cleavage site), they were not included in the sequence comparison. At the carboxy terminal end of the protein, the last 16 amino acids were excluded. This includes the region corresponding to the binding site of primer 2 (equivalent to last 7 amino acids) and then a gap of 9 further amino acids until the first sequence data were obtained. This terminal portion of the OspC genes appears to be highly conserved and of minor importance in generating the diversity observed among the OspC proteins as indicated by the ability to amplify and sequence the ospc gene from all strains tested using primer 2. Moreover, monoclonal antibodies which bind to this region of OspC are broadly reactive (for example, BBM 29, 42 and 45 in FIGS. 13 and 14.
The OspC sequences are highly variable with the most distantly related amino acid sequences ( B. burgdorferi strain 297 SEQ ID NO:12, and B.garinii strain IP90) SEQ ID NO:42, showing only 59% amino acid sequence identity (80% similarity). However, no sequence differences were detected between members of the same RFLP-type indicating that this typing method very accurately represents the heterogeneity among ospC genes (i.e. the OspC sequences for RFLP-type 1 strains VS215, VS219 and DK7 are identical to that of ZS7, SEQ ID NO:9,; RFLP-type 2 strains IP2, SEQ ID NO:5, and 26816 are identical to B31; RFLP-type 6 strains H15 and ACA1 are the same; RFLP-type 7 strains PKO and DK26 are identical to JSB, SEQ ID NO:25, RFLP-type 10 strains H4 and W, SEQ ID NO:31, are the same; RFLP-type 13 strains 871104 and KL11, SEQ ID NO:47, are identical; RFLP-type 14 strains 20047 and VS185 are the same).
The degree of relatedness between the partial OspC amino acid sequences determined by cluster analysis is presented as a dendrogram in FIG. 10 . OspC proteins from strains of the same species are more closely related to each other than to OspC proteins from different species. Nevertheless, even within one species, considerable variability is evident. The OspC sequence diversity is particularly high among the B.garinii strains, as indicated by the deeper branching observed within this part of the phylogenetic tree and the larger number of OspC variants associated with B.garinii than with the other two Borrelia species. The clonal structure of ospC inheritance suggests that there has been no significant exchange of genetic material, either by intragenic recombination or horizontal transfer of the plasmid-encoded ospC, between the different Lyme disease Borrelia species.
OspC proteins have been assigned to OspC families, an OspC family being defined as a group of OspC proteins that have more than 80% amino acid sequence identity over the first 92% of the mature OspC protein i.e. excluding the information for the 18aa leader sequence and the final 16aa. Eighteen different OspC families are depicted in FIG. 1 but two further OspC families (19 and 20) have been identified from incomplete sequence information for the OspC proteins from strains H13 and 28691 which has not been included in the dendrogram.
Despite the great diversity among the OspC proteins, the first third of the mature OspC protein is conserved (FIG. 10 ), with strains of the same species showing around 80-90% sequence identity in this region. However, the sequence identity between OspC proteins from different species is not so high in this part of the protein due to the presence of species-specific sequence motifs at the amino-terminal end of the OspC protein. As indicated above, the carboxy-terminal portion of OspC, which has not been shown, is also apparently highly conserved. The intervening region (i.e. the lower two blocks of FIG. 9 between amino acid residues KKI and NS) is highly variable and the major source of diversity associated with OspC. It is to be expected that serotype-specific epitopes would lie within this variable region. Analysis of the hydrophilicity profiles of the individual protein sequences, by the method of Hopp and Woods, found that the highest hydrophilic peak, highly predictive of the existence of an epitope, lies within this region. More specifically, despite the great variability between the OspC sequences in this region a putative epitope invariably lay between amino acid residues 120-155 of the mature protein. In the OspC of strain Orth, the hydrophilic peak occurs at residues 136-141 (DNDSKE amino acids 2-7 of SEQ ID NO 68), a region of high flexibility and a predicted β-turn, parameters which would also be indicative of an epitope (analyses done using PC/GENE).
EXAMPLE 5
Epitope Mapping of the Anti-OspC Monoclonal
The epitopes of certain of the anti-OspC monoclonal antibodies were mapped using a commercial available Custom Designated Epitope Scanning kit from Cambridge Research Biochemicals Ltd., Gradbrook Park, Northwich, Cheshire, England which uses either the pin technology method described by Geysen et al., J. Immunol. Methods 102: 259-74 (1987) or an biotinylated peptide ELISA or Dot Blot method described by the manufacturer. The 2026 custom synthesized peptides tested were single step, overlapping 10 mers of the OspC proteins sequences shown in FIG. 9 . Overlapping peptides of the signal peptide sequence of strain Orth and the C terminal ends of the OspC proteins of Strains Orth PKO and B31 were also included in the analysis.
The combined sequence of sequential peptides reacting with a monoclonal antibody is described as a “full epitope sequence”. FIG. 13 lists the full epitope sequence of those monoclonal antibodies for which epitopes could be discerned (SEQ ID NOS: 67-76). The sequence enclosed within brackets, [ ], includes the amino acids common to all reacting peptides and therefore form an important part of the epitope. The location of each full sequence within a generalized OspC protein the protein is shown in FIG. 14 . In one instance, e.g. with, a number of epitopes could be discerned, however, only that for the primary epitope, i.e., the most highly reactive, is given (FIG. 13) and shown (FIG. 14 ). In cases where the monoclonal reacted with peptides corresponding to similar regions in more than one Osp C protein only that for the Orth strain is given. Conversely, where the monoclonal antibody does not react with the Orth protein (e.g. BBM 43) the reacting sequence given is that for the homologous strain (PKO). At the bottom of FIG. 13 the monoclonal antibodies are grouped into categories based on the frequency of occurrence of the epitope they recognize which are shown in the upper part of the figure. As can be seen, over half of them recognize highly-specific epitopes, in that they occur in fewer than ten of the strains analyzed. Five of the monoclonal antibodies recognize epitopes of intermediate occurrence, while the seven remaining can be considered to recognize common epitopes because they occur in more than twenty five of the of the 77 strains analyzed. The monoclonal antibodies which were found to be suitable for the serovar analysis are denoted in FIG. 13 by an asterix. It is interesting to note that it was primarily the monoclonal antibodies that recognize common epitopes (BBM 28, 29, 34, 37, 42, 43, and 45) or those of intermediate occurrence (BBM 22, 35, and 40) which could be unequivocally mapped. Indeed only three monoclonal antibodies which could be considered as type specific (BBM 38, 39 and 44), i.e. reacting with fewer than 10 strains, could be mapped. Both BBM 38 and 39 have the same strain reaction pattern and mapped to the same region (amino acid 155 and 170) . Base on hydrophilicity plots of the amino acid sequence of the Orth protein, a hydrophilic peak and predicted β turn coincides with this region, parameters highly indicative of an epitope. The epitope of BBM 44 lies between amino acid 79 to 90, also an area of considerable variation. Unfortunately none of the epitopes of the other type specific monoclonal antibodies could be mapped, suggesting that they are dependent on the confirmation of the molecule. However, since all 3 type specific antibodies map to regions that are among the most variable of the protein, it is highly likely that it is also involved in other type specific epitopes. Interestingly, BBM 28 which reacts with an epitope of high frequency also maps to same regions as BBM 38 and 39. The reasons for this is unknown however there may be slight differences in the number and the actual amino acids involved at the binding site which bring about this ambiguity.
Four of the antibodies (BBM 29, 42, 43 and 45) which react with common epitope map at the distal C terminal end of the protein (amino acids 200 to 212), where as two others react close to the N terminal end of the protein (amino acids 41 to 67), regions which have been shown to be highly conserved. The monoclonal antibodies recognizing epitopes with intermediate occurrence mapped within the semi-conserved regions (amino acids 103 to 114 and amino acids 176 to 196) of the molecule.
These result were also confirmed in a further experiment where polyvalent rabbit sera specific for membrane 2 fractions of strains expressing each of the 16 serovar variants of the Osp C protein were screened against the 203 overlapping peptides of the Orth protein. All common, cross reacting epitopes were found within the conserved and semi-conserved regions outlined above. Interestingly sera from strains of CMAT group 1 ( B. burgdorferi sensu stricto) did not cross react as frequently as those sera from strains of CMAT groups 3 ( B. afzelii ) and 4 ( B. garinii ).
EXAMPLE 6
Cross-Protection Studies in Gerbils
To ascertain whether cross-protection between different OspC families was possible, ospC proteins were purified from B.burgdorferi strain ZS7 (OspC family 1), B.afzelii strain PKO (OspC family 7) and B.garinii strain W (OspC family 10) and used as immunogens in the gerbil model of Lyme borreliosis against a challenge with B.afzelii strain Orth (OspC family 5). To test protection within a family, the OspC from strain H7 (OspC family 5) was used as an immunogen against strain Orth. The OspC from strain H7 belongs to the same serovar and RFLP-type as the OspC from strain Orth.
Gerbils were given either a single, subcutaneous immunization of purified OspC (20 μg protein/200 μl, adjuvanted with TiterMax #R-1 (CytRx), that is, were prepared as a water-in-oil (squalene) emulsion with a synthetic immunomodulator (copolymer CRL89-41) or two intraperitoneal injections of ospC (10 μg protein/500 μl) adjuvanted with aluminium hydroxide. The purified antigens were prepared from strains by methods described in U.S. patent application Ser. No. 07/903,580, the contents of which were previously incorporated above by reference. Three and a half weeks after the first immunization, blood samples were taken from the eye and plasma prepared so that the antibody response to the immunogen at the time of the challenge could be ascertained (unimmunized control animals were likewise treated). Four weeks after the first immunization, the animals were challenged intraperitoneally with 10 4 cells (25-100 ID 50 ) of strain Orth, as were a group of unimmunized control animals. The challenge suspension was also titrated in unimmunized gerbils to determine the dose required to infect 50% of the animals. After a further two weeks, the animals challenged with the 10 4 dose were killed and the bladder, heart, kidneys and spleens cultured in BSK medium. Cultures were inspected for spirochetes at weekly intervals, from the second to the sixth week post-inoculation, by dark-field microscopy. Blood also was taken and the resultant plasma analyzed by western blotting for sero-conversion, i.e. the development of antibodies post-challenge to antigens from strain Orth other than the immunogen. There was good agreement between the cultural and serological tests used to ascertain which animals were infected. Only serological testing was used for the ID(50) determinations but in this instance the animals were bled three weeks post-challenge, the extra time being given to ensure that the antibody response in infected gerbils was sufficiently strong to be easily detected.
There were no signs of cross-protection between species i.e. OspC proteins from ospc families 1 ( B.burgdorferi ) and 10 ( B.garinii ) were ineffective as immunogens against the challenge strain Orth ( B. afzelii ). Likewise there was no sign of cross-protection between different OspC families of the same species i.e. the OspC protein from an OspC family 7 isolate ( B. afzelii strain PKO) was ineffective as an immunogen against a challenge with strain Orth which expresses an OspC protein from OspC family 5. By contrast, immunization with the OspC protein from strain H7 (OspC family 5) was effective against a challenge strain Orth (OspC family 5). These data (FIG. 15) indicate that cross-protection between the OspC families is unlikely and that protection within a family is possible. A multivalent vaccine comprising one or more types of OspC proteins from each of the OspC families should be sufficient to protect against most Lyme disease Borrelia strains.
EXAMPLE 7
Frequency of Occurence Geographical Distribution of Various Families of OspC Proteins Associated With Human Disease
Due to the high degree of variability of the OspC protein, it is extremely difficult to design vaccine formulations which give good protective coverage, yet do not require the inclusion of excessively large numbers of variants in order to achieve this goal. One way of optimizing the selection of OspC variants would be to determine which OspC variants are associated with human disease and occur with a high frequency. Rare OspC variants or OspC variants rarely associated with human disease would thus be excluded from any vaccine formulation with minimal loss of vaccine efficacy. Furthermore, if the vaccine is designed only for use in a particular geographic region, it would be unnecessary to include those OspC variants not prevalent among the Lyme disease Borrelia of that region. Using the epidemiological and OspC typing information on the Borrelia strains used in this study (FIG. 12) it has been possible to make selections on the OspC variants should be included in an OspC vaccine(s).
An analysis of the B.burgdorferi isolates (CMAT group 1 including strain 25015; total 23 strains) shows that the most prevalent OspC variants among those strains are those belonging to families 1 and 2. Family 1 strains are all European isolates and may cause human disease, although only 1 of the 5 strains was a human isolate which may be an indication that these strains are not highly virulent. Family 2 strains are the single most common type of OspC family with 10 members. Unlike family 1 strains, these strains are widely distributed with isolates from the United States, Europe and Russia. Family 2 strains are clearly associated with human disease with 50% of the isolates being clinical specimens. The remaining 8 B.burgdorferi isolates tested are all United States isolates and they are very diverse in terms of the OspC that they express, since each strain expresses a different OspC RFLP type. Only one of these strains (strain 297, family 3) was isolated from a case of Lyme disease. The family 2 and 3 strains belong, with the exception of strain 25015, to one of the 3 major human disease related clones CMAT type 1.2.4. (FIG. 5 ).
The 26 strains of B.afzelii (i.e. Group VS461, CMAT group 3) fall into 6 discrete families; OspC families 4-8 and family 16 with 5, 4, 6, 2, or 4 members respectively. Except for one Japanese isolate, all the strains were from Europe; Austria (14), Czech Republic (4), Denmark (1), Germany (2), Italy (1) Slovens (1), Sweden (1) and Switzerland (1). Eighty-eight percent of the European isolates were of human origin, with 80% of the isolates being from skin biopsies and 8% from blood samples. These data reflect a strong association between B.afzelii strains and the development of dermatological forms of Lyme disease. The human isolates were distributed evenly throughout the various OspC families. The Austrian isolates belonged predominantly to families 4-6 (86%) but single representatives were also found in families 7 and 8. The low incidence of Austrian isolates among OspC family 7 (i.e. ⅕) and the absence of isolates from family 16 (0/4) suggests that within Europe there are geographical variations in the prevalence of the various B.afzelii OspC families. Nevertheless, B.afzelii strains from the OspC families 4-8 and 16 are widely scattered throughout Europe. These strains are almost exclusively members of another major human disease related clone, namely 3.2.13. (FIG. 5 ).
Thirty B.garinii strains (i.e CMAT group 4, excluding atypical strains 19857 and 19952, and CMAT 2 strains 20047, IP90 and NBS16) can be sub-divided into 9 OspC families plus 2 RFLP types for which there is no family assignment. Fifty-three percent of the B.garinii strains tested were human isolates and these strains are distributed throughout all but one (RFLP 34) of the OspC types. Seventy-five percent ({fraction (12/16)}) of these B.garinii strains were isolated from cases of neuroborreliosis with the remainder being skin isolates. Therefore, B.garinii is primarily associated with neuroborreliosis, although the occurence of skin isolates is to be expected since the development of a skin-lesion (EM) is a manifestation common to all forms of Lyme disease irrespective of the causative agent. Strains of OspC family 13 were the most commonly isolated OspC type, accounting for 23% ({fraction (7/30)}) of the total B.garinii OspC types and 25% ({fraction (4/16)}) of the human isolates. strains of this ospC family are widespread within Europe and include isolates from 6 different countries. OspC family 11 is also widely distributed and occurs reasonably frequently (17% or {fraction (5/30)}) but the association with human disease is less clear, since only one isolate was of human origin, but this may reflect sampling error and the small numbers of strains analysed. These latter comments are also applicable to strains of OspC family 14 (4 strains but only 1 human isolate). Isolates from the other OspC families ( 9,10,12,15,17,19 and RFLP types 33 and 34) were found at a lower frequency. However, for a vaccine against Austrian B.garinii strains OspC families 10 and 19 should be considered, in addition, since all 4 B.garinii isolates from Austria belonged to these 2 OspC families.
In addition, to the direct analysis of Borrelia strains, as described above, it is also possible to determine the prevalence of the various OspC variants and their association with human borreliosis indirectly. This can be achieved by testing the specificity of OspC antibodies in the serum from Lyme disease patients. Fifty sera taken from patients in the Prague area (Czech Republic) suffering from EM (15), ACA (15), neurological disorders (10) or joint and muscle associated syndromes (10) have been tested for antibodies to OspC. When screened against a panel of 18 strains, 17 (34%) of the sera (3 EM, 10 ACA, 3 Lyme arthritis and 1 neuroborreliosis) were found to react with one or more of the 16 OspC families tested (FIG. 16 ). Twelve of the sera reacted specifically with just one OspC [family 5 (4×), family 7 (3×), family 6 (2×), family 8, 13 and 14 (1×)]. Three sera reacted with both families 4 and 6 while 2 other sera were broadly cross reactive reacting with 6 and 8 of the families tested. Therefore, Borrelia strains expressing OspC variants from OspC families 5-7, 13, 14 and probably 4 are present in the Czech Republic. This serological data is consistent with, and therefore substantiates, the results obtained from the strain analysis for the neighbouring country Austria.
Based upon the results described above, vaccines have been formulated for use in;
1) United States; OspCs from OspC families 2 and 3
2) Europe; 14 OspC variants from OspC families 2, 4-7, 9, 10, 12, 13, 14, 15-17 and 19
3) Austria; 8 or more OspCs from OspC families 2,4-7,10,13 and 19.
EXAMPLE 8
Expression of Recombinant OspC in P.pastoris
Construction of the Pichia pastoris OspC Expression Vector
The recombinant P.pastoris/E.coli shuttle vector pHIL-A1 (provided from Phillips Petroleum) was used to clone the OspC coding sequence of B.burgdorferi. A panel of strains comprising one or more representatives from each family was selected and the OspC gene was amplified by the polymerase chain reaction. The coding sequence of the mature OspC protein starting with the first cysteine amono acid (amino acid 19 in the OspC protein sequence from strain Orth) was amplified by using the strain specific primers deduced from the OspC nucleotide sequences as disclosed U.S. Ser. No. 07/903,580 (EP 0 522 560).
To create the 5′ and 3′ end of the B.burgdorferi Orth OspC gene, the polymerase chain reaction (PCR) was carried essentially as described in Example 4 using the amino-terminal primer PC-F with the sequence 5′-AA ATG TGTAATAATTCAGGGAAAGG-3′ (SEQ ID NO:61), and the carboxy-terminal primer PC-B with the sequence 5′-A TTA AGGTTTTTTTGGAGTTTCTG-3′ (SEQ ID NO:62). The underlined sequence in primer PC-F is identical to the translation start codon of the mature OspC protein and in primer PC-B to the translation stop codon, respectively.
Cloning strategies (restriction site in the vector and primers used for PCR) for inserting OspC coding sequence of B.burgdorferi strain B31, PKO, ZS7, KL10 and E61 in pHIL-A1 are summarized in the Table 1 below.
The vector pHIL-A1 was digested with SfuI and overhanging ends were filled in with Klenow polymerase to create blunt ends. The purified PCR fragment containing the OspC coding sequence was ligated with the vector overnight. The ligation mixture was used to transform competent E.coli DH5α and ampicillin resistant colonies were selected on LB-Amp-plates for further plasmid amplification. Mini-preparations (Maniatis et al. 1982) were screened and analysed by restriction fragment length and the plasmid having the OspC gene was labelled pPC-PP4 (FIG. 17 ). Purified pPC-PP4 DNA was prepared and the sequence was confirmed by DNA sequencing. The purified plasmid pPC-PP4 was transformed in P.pastoris strain GS115 NRRL-Y 11430 (Cregg et al. Mol. Cell. Biol. 5: 3376-3385 (1985)) by the method described by Dohmen et al. 1991 (Yeast 7: 691-692) and transformants were selected on MD plates.
B. burgdorferi Strain
Primer
Vector pHIL-Al digested
Orth
5′-AA ACG ATG TGT AAT AAT TCA GGG AAA GG-3′
SfuI/Klenow
SEQ ID NOS 63 and 64
5′-ATTAAGGTTTTTTTGGTTTCTG-3′
KL10
5′-GGGACTTCGAAACGA ATG TGTAATAATTCAGGTGGG-3′
SfuI/EcoRI
SEQ ID NOS 65 and 65
5′-GGA ATT CAT TAA GGT TTT TTT GGA-3′
ZS7
5′-CGGACTTCGAAACGA ATG TGTAATAATTCAGGGAAAG-3′
SfuI/EcoRI
SEQ ID NOS 77 and 66
5′-GGA ATT CAT TAA GGT TTT TTT GGA-3′
B31
5′-CGGACTTCGAAACGA ATG TGTAATAATTCAGGGAAAG-3′
SfuI/EcoRI
SEQ ID NOS 77 and 66
5′-GGA ATT CAT TAA GGT TTT TTT GGA-3′
E61
5′-CGGACTTCGAAACGA ATG TGTAATAATTCAGGGAAAG-3′
SfuI/EcoRI
SEQ ID NOS 77 and 66
5′-GGA ATT CAT TAA GGT TTT TTT GGA-3′
PKO
5′-CGGACTTCGAAACGA ATG TGTAATAATTCAGGGAAAG-3′
SfuI/EcoRI
SEQ ID NOS 77 and 66
5′-GGA ATT CAT TAA GGT TTT TTT GGA-3′
Table 1 shows the oligonucleotide primers used for the PCR amplification of the coding sequence of the mature QspC protein of different Lyme disease Borrelia strains. The restriction enzymes used for insertion of the OspC coding sequence in the pHIL-Al vector are also given.
Expression of Recombinant OspC in P.pastoris
P.pastoris GS115/pPC-PP4 transformants were picked from MD plates and grown in 3 ml MG medium at 30° C. with constant agitation to an optical density (OD 600) of 2-10. For induction of OspC synthesis, one ml of the culture was spun down, washed once with MM, resuspended in 3 ml of MM or MMY 1 -medium and incubated for 2 days at 30° C. with constant agitation. Expression of OspC was induced by the presence of methanol in the growth medium. Aliquots of the culture were removed and lysates were Western blot analysed using OspC specific monoclonal antibody BBM 45.
[ 1 all of the following media are expressed in terms of quantity /1
MD: Yeast nitrogen base (YNB, 13.4 g), ammonium sulfate (5 g), biotin (400 mg), glucose (2%)
MG: YNB, ammonium sulftate, biotin, glycerol (10 ml/l), potassium phosphate (100 mM)
MM: YNB, ammonium sulftate, biotin, methanol (5 ml), potassium phosphate (100 mM)
MMY: MM, yeast extract (10 g), casein (20 g)]
Purification of Recombinant OspC
P.pastoris GS115/pPC-PP4 cell were harvested by centrifugation (3000 g, 5 min , 4° C.). The washed cells were resuspended in 150 mM Tris/HCl buffer, pH 7.4 and the suspension was added to glass beads. The cells were then lysed by shaking the mixtures in a Vibrogen® cell-mill (Model V14, Bühler). The lysate was then filtered on a sintered glass filter to remove the glass beads. The lysate was centrifuged for 5 min at 3000 g at 4° C. The supernatant was further centrifuged for 1 hour at 100,000 g at 4° C. The “high speed supernatant” was used for further purification of the OspC antigen.
OspC antigens were fractionated by DEAE-chromatography, as exemplified below:
Column: Protein-PAK DEAE 5PW from Waters
Sample: 45 ml dialysed antigen preparation
Equilibration buffer (A): 10 mM Tris/HCl pH 7.5
Eluation buffer (B): 10 mM Tris/HCl, 1 M NaCl, pH 7.5
Flow rate: 4 ml/min
Gradient: 0% B for 70 min, 0-100% for 50 min
The column was equilibrated with buffer A and the antigens eluted with increasing amounts of NaCl. To identify fractions containing the antigen of interest, aliquots of fractions were precipitated with acetone and the pellets were analyzed by SDS-PAGE and/or immunoblotting.
Fractions from the DEAE ion-exchange chromatography separation enriched for OspC antigen were further purified by immobilized metal-affinity chromatography as described in EP 0 522 560.
Large Scale Production of OspC Protein in the Fermenter
The production of OspC was examined in continuous fermentation run. Each run was performed using a fermenter equipped with monitors and controls for pH, dissolved oxygen, agitator speed, temperature, air flow and oxygen flow. Temperature was held at 30° C. Cell yield was determined from washed cell wet weight.
Inocula for the fermenter runs were grown in 2 l Erlenmeyer flasks containing 500 ml of modified FM21 medium as disclosed in EP 0 263 311. The fermenter cultures grown in the batch mode were propagated with glycerol as sole source of carbon and energy. Continous cultures were established with constant glycerol feed until a biomass concentration of 500-700 g wet cell weight/liter was reached. Once baseline control samples were taken, methanol was added to the culture as methanol-salts-biotin feed over a period of several days to keep the methanol concentration between 0,05 and 1,5 %. Produced biomass were removed every day. P.pastoris cells were collected by centrifugation and resuspended in buffer (150 mM Tris/HCl, 2 mM EDTA, 1 mM benzamidine hydrochloride, 0,1% NaN 3 , pH 7.4). Cell lysates were obtained by using French press. OspC protein concentration was determined by the method of Bradford. Preliminary results showed an antigen production of about 100 fold increased yield of ospc antigen (per unit volume culture)derived from P.pastoris compared to the yields obtained from the B.burgdorferi strains.
Immunization and Challenge (Protection) Studies of the P.pastoris Derived OspC Antigen
Protection studies were performed in gerbils as described in example 6. Twenty microgram amounts of OspC from P.pastoris (cloned from strain Orth) or Borrelia strain Orth were tested for their protective efficacy as shown in FIG. 18 . All gerbils immunized with P.pastoris derived OspC were protected against a challenge with the homologous strain Orth and results are comparative to protection studies obtained with Borrelia derived OspC antigen. | A novel approach to Borrelia vaccine formulation taking into account serological, genotypic and epidemiological information by which OspC proteins from different strains of B burgdorferi are grouped together. OspC antigens are chosen in order to constitute a representative sample of such groupings, so that the resulting vaccine provides the greatest cross-protectivity with the fewest number of antigens. | 2 |
FIELD OF THE INVENTION
The present invention relates to passenger conveyors like escalators and moving walks and particularly relates to a method for compensating a movable handrail in a passenger conveyor having a passenger transportation belt defining at least one passenger transportation surface, wherein the handrail is traveling along a closed handrail path which extends through an exposed path along the passenger transportation belt, around a turnaround means, through a return path and around a further turnaround means, and which handrail path defines a handrail plane which is substantially perpendicular to the passenger transportation surface.
DESCRIPTION OF THE RELATED ART
Such passenger conveyors are widely in use. The handrails thereof are typically made from a rubber or plastics material and are internally reinforced by reinforcing elements like reinforcing longitudinal cables which are typically made from metal material. The handrail is typically a closed loop and has a length depending of the particular application, but typically at least 30 to 35 meter. In order to compensate for manufacturing tolerances as well as shortening which occurs due to aging of the handrail, a length compensation of the handrail is typically made. To this end at least one compensation device is placed in the return path of the handrail. The manufacturing tolerances, which are substantially independent from the handrail length, are ±12.5 mm so that a length compensation of typically at least 60 mm but preferably between 60 and 75 mm or even more is desired. With existing passenger conveyors, these compensation devices consume space within the plane as defined by the handrail path. This space is, however, required for placing other components of the passenger conveyor like the passenger transportation belt guiding elements, e.g. step roller tracks, or drive elements like step chains or step chain drives. Particularly with “slim” modern passenger conveyors and particularly with class-balustrade conveyors, this space problem is acerbated. Thus, with such construction frequently the problem emerges that conventional compensation devices cannot be used due to the fact that they require too much space or a plurality of such compensation devices is required for a single handrail in order to provide sufficient compensation length.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a method and a device which obviates the space problem with the prior art passenger conveyors and which provides the designer with more flexibility for designing the arrangement of the components of the passenger conveyor in an area where space is of premium concern.
In accordance with an embodiment of the present invention this object is solved by a method as defined above including the following steps:
(a) turning the handrail out of the handrail plane;
(b) directing the handrail through a compensation means; and
(c) turning the handrail back into the handrail plane.
The object is further solved with a handrail compensation device having a compensation means and a means for turning the handrail around its longitudinal axis.
By turning or twisting the handrail around its longitudinal axis, it is possible to tilt the compensating device out of the plane of the handrail path and away from that portion of the passenger conveyor where space is particularly restricted. Particularly, it is to tilt the compensation device by an angle which is sufficient for allowing the handrail in the compensation device to travel laterally past other components which are positioned within or extending into the plane as defined by the handrail path.
It is preferred to turn the handrail around its neutral longitudinal axis in order to reduce or avoid unnecessary flexing work.
Preferably the step of turning (or deflecting) the handrail out of the handrail plane comprises turning the handrail out of the handrail plane by between approximately 2° and 30° (e.g., an oblique angle). Other values particularly within this range are possible, for example between approximately 5° and 25°, between approximately 10° and 20° and between 12° and 18°.
Preferably, the handrail compensation device comprises first turning means in the moving direction of the handrail, followed by the compensation means and a second turning means. The first turning means can turn the handrail by a predetermined amount in a first direction and the second turning means can turn the handrail by the same predetermined amount in the opposite direction. Such a construction shows that the handrail moves in exactly the same direction before and after the compensation device. It is also possible to not turn the handrail in one single step by the desired amount but to provide a plurality of turning means for even a continuous turning means over a prolonged distance in order to achieve a predetermined turning angle.
Preferably, the turning means comprises a first and second guide roller sets each for contacting the handrail on its upper side, i.e. the side which is to be contacted by the user, and its inner side, i.e. the side which faces away from the upper side wherein the second guide roller set is angularly offset with respect to the first guide roller set so that in use the handrail is turned while traveling from the first to the second guide roller set. Each guide roller set preferably forms a slit or nip through which the handrail passes. The angular difference between the first slit and the second slit defines the angular offset and consequently the handrail turning angle. Instead of the guide roller sets any other guiding elements like sliding contact plates or moving contact belts can be used. It is preferred that such alternative guide means also form a slit or nip for guiding the handrail.
Preferably, the second roller set comprises two inner rollers on that side which in use is adjacent to the inner side of a generally C-shaped handrail, said two inner rollers are arranged with its rotational axis substantially perpendicular to each other so that in use one of the inner rollers will contact the lateral legs of the C-shaped handrail while the other inner roller will contact the web between the legs. In order to provide for a secure guidance of the inner side of the handrail, a single roller needs a relatively large diameter which might collide with space requirements. In order to obviate this problem, an embodiment of the invention suggests using one roller or disc which has a diameter slightly smaller than the distance between the two legs of the C-shaped handrail and using a further roller whose circumferential surface contacts the web portion between the two legs and which may have a relatively small diameter. This double roller arrangement can be constructed in a way that it is only slightly extending above the thickness of the handrail.
Preferably, the first and second roller sets are spaced from each other by a distance that is at least two times the width of the handrail. The distance between the first and second roller sets corresponds to the length through which the handrail is turned around its longitudinal axis. It is preferred to turn the handrail in a way that the lateral legs of the C-shaped handrail do not flex or flex only at a minimum amount. This will avoid aging of the handrail due to flexing work. In order to avoid this aging, a predetermined distance is provided between the first and second roller sets.
Preferably, the compensation means comprises a compensation roller, in use acting against the inner side of the handrail and bulging the handrail in the direction of the upper side thereof, and wherein the second roller set is offset by a predetermined distance from the first roller set in a direction opposite to the bulging direction of the compensation roller. With such a construction the handrail is—as viewed from the side—first directed upward between the first and second roller sets and subsequently directed downward by the compensation roller before it is directed back to the second roller set of the return turning device and again downward towards its original direction. With such a construction a particularly compact compensation device can be realized.
An embodiment of the invention further relates to a passenger conveyor having a passenger transportation belt defining at least one passenger transportation surface and a movable handrail which is traveling along a closed handrail path extending through an exposed path along the passenger transportation belt, around a turnaround means, through a return path, and around a further turnaround means, and defining a handrail plane which is substantially perpendicular to the passenger transportation surface, further comprising a compensation means and a means for turning the handrail around its longitudinal axis. The turning means does not necessarily have to be a part of the compensation device, but can be located at other positions, preferably along the return path of the handrail. One might contemplate to guide the handrail over an extended distance in a tilted manner and possibly out of the plane of the handrail path and to position the compensation means in such portion.
Preferably, the passenger conveyor comprises a compensation device according to an embodiment of the invention.
Preferably, some or all components of the compensation device are mounted to a support element, for example a support plate. Such support element can be mounted with the predetermined turning angle in the passenger transportation device. By providing virtually all the components on the single support element, these components can be aligned with ease in the factory and can easily be assembled in the conveyor, for example attached to the conveyor trust, etc. without the need for mounting and aligning the components individually.
Preferably, the components of the compensation device or alternatively the support element are/is attached to precisely aligned components of the passenger transportation device. Such precisely aligned components can for example be the step roller tracks, the chain roller tracks, the balustrade holder, etc. By providing a suitable mounting arrangement, for example mating surfaces, specific fasteners, etc. it is possible to design the passenger conveyor in a way that the components of the passenger transportation device are precisely aligned by merely securing it to the respective aligned components. Such a design can substantially reduce the efforts for assembling the passenger conveyor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and embodiments of the invention are described in greater detail below with reference to the Figures, wherein:
FIG. 1 shows a passenger conveyor;
FIG. 2 shows a compensation device in accordance with an embodiment of the invention with minimum compensation in perspective view;
FIG. 3 shows an end view of the compensation device of FIG. 2 with minimum compensation;
FIG. 4 shows a compensation device in accordance with an embodiment of the invention in perspective view similar to that of FIG. 2 , but in the state of maximum compensation;
FIG. 5 shows an end view of the compensation device of FIG. 4 with maximum compensation;
FIG. 6 shows a perspective view of the compensation device in accordance with an embodiment of the invention as attached to the components of the passenger conveyor;
FIG. 7 shows a similar view to that of FIG. 6 of the compensation device, but without the remainder of the passenger conveyor;
FIG. 8 shows a side view of the compensation device in accordance with an embodiment of the invention as attached to components of the elevator conveyor; and
FIG. 9 shows a perspective view of the compensation device without surrounding components.
DETAILED DESCRIPTION
FIG. 1 shows a passenger conveyor 2 and particularly an escalator having a passenger transportation belt 4 comprised of a plurality of steps 6 , the treats thereof form a plurality of passenger transportation surfaces 8 . The escalator 2 further comprises two movable handrails 10 . Each handrail 10 is traveling along a closed handrail path which extends through an exposed path 12 where the handrail 10 is exposed to the passengers and travels in parallel to the passenger transportation surfaces 8 . The closed handrail path further comprises a upper turnaround means 14 , a return path 16 which is nearly completely covered in the Figure and runs below the passenger transportation belt 4 , and a lower turnaround means 18 . The turnaround means 14 and 18 are frequently termed newels. The escalator 2 further comprises a truss 20 for mounting the escalator in the building and for supporting escalator components like an escalator drive 22 , a chain drive sprocket 24 driving the escalator chain 26 and step roller tracks 28 . The person skilled in the art will understand that in the perspective view of FIG. 1 some parts of the escalator 2 are broken away for showing details which would otherwise be hidden.
In FIG. 1 also the glass panels 30 of the lateral balustrades 32 are shown. The glass panels 30 are at the lower end thereof supported by a glass holder profile 34 and support at their upper end a (not shown) handrail guide profile. The closed handrail path defines a handrail plane which substantially coincides with the glass panels 30 and which is substantially perpendicular to the passenger transportation surfaces 8 and extending in a vertical direction, respectively.
FIG. 2 shows a perspective view of a handrail compensation device 36 in accordance with an embodiment of the invention. The handrail compensation device 36 includes a handrail compensation means 38 as well as a first twisting or turning means 40 and a second twisting or turning means 42 . FIG. 2 further shows part of the truss 20 and the glass holder profile 34 . A step roller track 44 and a step chain roller track 46 are also visible in FIG. 2 . The handrail compensation means 38 comprises a compensation bow 48 including a plurality of compensation bow rollers as well as two back bending roller bows 50 which also comprise a plurality of back bending rollers.
One can further see that the handrail 10 generally is of C-shaped cross section having two lateral legs 52 protruding away from a central web 54 (see FIG. 5 ).
The first and second turning means 40 , 42 are each shown as comprising a first 56 and a second 58 guide roller sets. The first and second guide roller sets 56 , 58 each define a slit or nib through which the web 54 of the handrail 10 is guided. The extension of the slit with the guide roller set 56 is perpendicular to the plane as defined by the handrail path. The slit of the second roller set 58 is angled with respect thereto by a predetermined amount which finally defines the twist or turning amount of the handrail. The second guide roller set 58 may comprise one or more rollers of the back bending roller bow 50 .
As may be seen by comparing FIGS. 2 and 4 , the compensation bow 48 can be varied between a minimum compensation position as shown in FIG. 2 and a maximum compensation position in FIG. 4 . One can further see in FIG. 4 a supporting element 60 in the form of a support plate. The holder 62 for the compensation bow is slidingly attached to the support plate 60 .
FIGS. 3 and 5 show end views of the handrail compensation device 36 as shown in FIGS. 2 and 4 , respectively. One can particularly see in FIG. 3 that the handrail 10 would collide with the step roller track 44 if the compensation device 38 would simply bend it downward as it was conventional with the prior art. There is only limited space between the handrail 10 and the upper portion of the step roller track 44 , which is not sufficient for providing the required compensation. One can clearly see in FIG. 5 that due to the twisting or turning of the handrail and the tilted arrangement of the compensation means 38 sufficient compensation can be provided due to the fact that the handrail 10 passes laterally by the step roller track 44 . Thus FIGS. 3 and 4 illustrate clearly how an embodiment of the invention solves the space-related problems which are inherent with the compensation devices of the prior art.
FIG. 6 is a further perspective view of the handrail compensation device 36 similar to that of FIG. 4 with the compensation being near maximum. In FIG. 6 one can clearly see the handrail which is twisted between the first guide roller set 56 and the second guide roller set 58 . One can further see in FIG. 6 that the handrail 10 is first directed upward from the first guide roller set 56 to the second guide roller set 58 before it is directed downward through the compensation bow and then up again to the second guide roller set 58 of the second turning means which directs the handrail 10 down again and back again in its original direction.
FIG. 6 again shows parts of the truss 20 as well as the glass holder profile 34 and the step roller track 44 . It is to be noted that the glass holder profile 34 and the step roller track 44 are components of the escalator 2 which are very precisely aligned. Accordingly, by fixing the handrail compensation device 36 to one and/or the other of those parts, a perfect alignment thereof can achieved without the need for individual alignment of the handrail compensation device and/or its individual components. Beams 64 -which are attached to the support plate 60 attach the handrail compensation device 36 to the glass holder profile 34 . A holder 66 for the first guide roller set 56 is attached to the step chain roller profile 48 .
FIG. 7 is a view similar to that of FIG. 6 , but with the components beyond the handrail compensation device 36 being omitted. In this view the second roller set 58 is better visible than in the previous Figures. One can particularly see that the second roller set 58 comprises two inner rollers 68 and 70 . These inner rollers 68 and 70 contact the inner side 72 of the handrail 10 . The inner side 72 of the handrail 10 is opposite to the upper side 74 or outer side, which is exposed to the passengers in the portion of the handrail path along the passenger transportation belt. One can particularly see that the two inner rollers 68 and 70 are arranged with its rotational axis substantially perpendicular to each other so that in use the disc-shaped inner roller 68 contacts the lateral legs 52 of the C-shaped handrail 10 while the other inner roller 70 which has the form of a cylindrical roller, contacts the web 54 between the legs 52 . The disc 68 has a slightly smaller diameter than the distance between the two legs so that it guides either one or the other leg 52 . Accordingly, the two inner rollers 68 , 70 require by far less height than the conventional inner roller 76 in the first guide roller set 56 . This allows for directing the handrail upward between the first and second guide roller sets 56 , 58 despite the space restriction imposed by the presence of the overlaying glass holder profile 34 (see FIG. 6 ).
FIG. 8 is a side view of the handrail compensation device 36 according to an embodiment of the invention which illustrates the restricted space between the second guide roller set 58 and the glass holder profile 34 . FIG. 9 illustrates the fixation points for the handrail compensation device. One can see that with the exception of the first guide roller set 56 all components are fixed to the support plate 60 which is secured to the underside of the glass holder profile 34 by way of the beams 64 and which is further supported by way of the support 78 to either of the two guide rails 44 , 46 , but preferably to the step chain roller track 46 . Thus, by way of fixing the support plate 60 at three fixation points, its fixation is statically defined. The first guide roller sets 56 are each individually attached by way of holder 66 to the step chain roller track 46 . | Method for compensating the length of a movable handrail ( 10 ) in a passenger conveyor ( 2 ) having a passenger transportation belt ( 4 ) defining at least one passenger transportation surface ( 8 ), the handrail ( 10 ) is traveling along a closed handrail path which extends through an exposed path ( 12 ) along the passenger transportation belt ( 4 ), around a turnaround means ( 14 ), through a return path ( 16 ) and around a further turnaround means ( 18 ), and which hand rail path defines a handrail plane which is substantially perpendicular to the passenger transportation surface, the method comprising the following steps: (i) turning the handrail ( 10 ) out of the handrail plane; (ii) directing the handrail ( 10 ) through a compensation means ( 38 ); and (iii) turning the handrail ( 10 ) back into the handrail plane. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compositions for the internal sizing of paper and, more particularly, it relates to ketene dimer/nonreactive hydrophobe compounds providing improved sizing results.
2. Description of the Prior Art
The main component of paper and paperboard is cellulose fiber. The flat web of cellulose fibers may contain inorganic fillers, starch, pigments and other papermaking adjuvants. Such paper and paperboard would readily absorb aqueous liquids. This property would be a serious disadvantage when the paper is used in printing or coating or pasting operations. Also, most papermaking machines apply a surface coating to the semidried paper using an aqueous coating mix at a size press. The application of a surface coating to a paper or board as above is technically difficult, especially at the lighter weights of paper.
These technical difficulties have been overcome by sizing the paper and paperboard. Sizing agents are used to impart to the paper and paperboard resistance to aqueous penetrants. Various types of sizing agents have been used commercially over many years. Most end use applications for the paper require that the paper is sized internally--that is the sizing agent is added to the paper components before the paper web is formed.
Ketene dimer sizing agents were introduced to the paper industry in the late 1950's and early 1960's. These allowed for the first time the production of internally sized paper and paperboard under neutral to alkaline pH conditions. Traditionally clay had been used as the filler but now chalk could be used within the neutral/alkaline papermaking conditions. Paper and paperboard made under these conditions has many commercial advantages, and the use of ketene dimer sizing agents has now spread throughout the worldwide papermaking industry. Ketene dimers are water insoluble products and they are used largely in the form of aqueous dispersions which are added to the papermaking stock.
After the wet web of paper has been formed on the papermaking machine it is dried by passing around a series of heated cylinders. This period of heating and drying promotes a chemical reaction between the ketene dimer and the hydroxyl groups on the cellulose fiber, possibly also with hydroxyl groups on the fillers. This chemical reaction is time and temperature dependent. On some papermaking machines the duration of heating is sufficient to promote the chemical reaction to such an extent that a sizing effect results on the machine. This, however, is not the case on most papermaking machines since they are operated at maximum speed to optimize paper production and this reduces the period of the heating and drying. Consequently most papermaking machines using ketene dimer sizing agents alone do not make sized paper on-machine. This detracts from the operation of the size press. The chemical reaction between dimer and hydroxyl groups does continue in the dried paper but it may take several days to reach naturally its full sizing development. This slow development of sizing creates problems with the conduct of further operations such as printing, coating, pasting, etc.
This problem of the slow development of sizing with ketene dimers alone has received considerable attention over the years. A solution used commercially since the early 1970's has been to employ a promoter resin with the ketene dimer. Promoter resins of dicyandiamide/formaldehyde condensates have been used successfully to speed up the development of sizing. Another potential solution is to employ with the ketene dimer another sizing agent which will give an immediate effect on-machine. One such additional sizing agent is wax as proposed in Japanese Patent J58 087395. Others such as pentaerythritol aliphatic acid esters, polyalkylene glycol di-aliphatic acid esters, mono-and/or di-fatty acid esters of alkane diols, polyvalent metal salts of fatty acids, fatty cane sugar esters and polyalkylene glycol mono-fatty acid esters have been proposed in Japanese Patents J58 091895, J58 091894, J58 087396, J57 112499, J57 101096 and J57 101095 respectively.
Japanese Patent J57 112498 proposes the use of mixtures of ketene dimers with di- and/or triglycerides as being sizing agents that can be used in neutral and alkaline conditions and which give a sizing effect in a short time. The appropriate amounts to use are 5-100 parts of glyceride, preferably 10-50 parts of glyceride, relative to 100 parts of ketene dimer to give degrees of sizing in a short time of approximately 50-68 percent of the degree of natural cure after one day. The use of these mixed size systems does not increase the level of sizing after one day above that achieved by the use of ketene dimer alone.
A further disadvantage of a ketene dimer sizing agent is that it can react with water to yield and ineffective ketone. This action reduces the efficiency of the sizing agent.
The object of the present invention is to provide a sizing agent that includes the use of a ketene dimer within its composition that sizes paper and paperboard within a short time and improves the efficiency of the ketene dimer.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a composition comprising
(a) ketene dimer having the general formula
[RCH═C═O].sub.2
wherein R is an alkyl radical having from 6 to 22 carbon atoms, a cycloalkyl radical having at least 6 carbon atoms, an aryl, aralkyl or alkaryl radical, and
(b) nonreactive hydrophobe compound, provided, however, that the melting point of said nonreactive hydrophobe is higher than the melting point of said ketene dimer and the ketene dimer to hydrophobe ratio is from about 1:100 to about 99:100 by weight.
Further provided according to the present invention is a process of sizing paper internally by adding to the papermaking stock the composition of the present invention.
Still further provided according to the present invention is paper sized internally with the composition of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It has surprisingly been found that a composition of ketene dimer and nonreactive hydrophobe compound, wherein the melting point of the hydrophobe compound is higher than the melting point of the ketene dimer, results in the sizing of paper and paperboard within a short time and the efficiency of the ketene dimer is also improved by such combination which is a fatty acid ester derived from fatty acids having from 10 to 24 carbon atoms and alcohols having from 1 to 5 carbon atoms selected from the group consisting of mono-, di- and polyhydric alcohols, the melting point of said fatty acid ester is at least about 10° C. higher than the melting point of said ketene dimer, and the ketene dimer to fatty acid ester ratio is from about 11:100 to about 75:100 by weight.
The ketene dimers (KD's) which may be used as components of the present composition may be any of the known KD's having the general formula
[RCH═C═O].sub.2
wherein R is an alkyl radical which may be saturated or unsaturated having from 6 to 22 carbon atoms preferably from 10 to 20 carbon atoms and most preferably from 14 to 16 carbon atoms; a cycloalkyl radical having at least 6 carbon atoms or an aryl, aralkyl or alkaryl radical. These known KD's are as described in U.S. Pat. 2,785,067. The KD may be a single species or may contain a mixture of species.
Suitable KD's include decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl cyclohexyl, phenyl and benzyl-β-napthyl ketene dimers, as well as KD's prepared from palmitoleic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, myristoleic acid and eleostearic acid or mixtures thereof.
According to a preferable embodiment of the present invention, the nonreactive hydrophobe compound is fatty acid ester which can be natural or synthetic, saturated or unsaturated or mixtures thereof. They are based on C10-C24 fatty acids, preferably C14-C22 saturated fatty acids and most preferably C16-C18 saturated fatty acids. The esterification may be achieved by use of mono-, or di- or polyhydric alcohols having from 1 to 5 C atoms to yield monoesters, diesters, or polyesters, respectively. Included in the polyesters are the triglycerides which may be natural or synthetic in origin. Preferably the esterification is carried out by use of C2 to C5 di- and polyhydric alcohols, and most preferably C3 trihydric alcohol (glycerol).
The benefits of this invention are gained when the ketene dimer is blended with the hydrophobe in a ratio of from about 1 to about 99 parts by weight of dimer to about 100 parts of hydrophobe. More beneficial is a ratio of from about 5 to about 75 parts of ketene dimer to about 100 parts of hydrophobe. The most preferred ratio is from about 11 to about 50 parts of dimer to about 100 parts of hydrophobe.
When selecting the type of ketene dimer and the type of nonreactive hydrophobe to work together in this invention it is necessary to ensure that the melting point of the selected nonreactive hydrophobe is above that of the selected dimer, preferably at least about 10° C. higher, and most preferably at least about 20° C. higher than the melting point of the dimer.
Conventionally, ketene dimers have been made into stable, aqueous dispersions with particle sizes in the approximate region of 1-5 microns using conventional cationic or anionic or nonionic dispersing agents. Suitable stabilizers are e.g. starch, cationic starch, anionic starch, amphoteric starch, water soluble cellulose ethers, polyacrylamides, polyvinyl alcohol, polyvinyl pyrrolidone (PVP) or mixtures thereof. It is to be expected that any stabilizer known in the art will be suitable in some of the applications envisaged. Preferred stabilizers are starch, cationic starch and PVP and the most preferred stabilizers are the cationic starches. The amount of stabilizer used will depend on the solids content of the dispersion necessary for any particular application, but can be readily determined by routine experiment by a person skilled in the art. Generally the stabilizer will be present in an amount of from about 1 to about 30% based on the weight of KD/hydrophobe, preferably from about 3 to about 20% and most preferably from about 5 to about 10%.
The dispersion of the present invention may also include other additives commercially used in the art, such as promoter resins for the KD's, biocides, etc.
Stable aqueous dispersions of the nonreactive hydrophobes may be made by conventional means as outlined above for the ketene dimer dispersion.
It is a requirement of this invention that the ketene dimer and the nonreactive hydrophobe be brought together in a particular manner such that the objects of this invention are achieved. This has been achieved by the following methods which are not limiting. The hydrophobe and the ketene dimer can be melted and blended together prior to being made into an aqueous dispersion by conventional means. Alternatively, a hot, aqueous dispersion of the ketene dimer can be mixed with a hot, aqueous dispersion of the hydrophobe. The resultant blended aqueous dispersion is used at ambient temperatures. The benefits of this invention are not gained if these two dispersions are mixed when at ambient temperatures, nor are the benefits gained if the two dispersions are added separately to the paper stock.
Japanese patent 57 112498 uses dispersions of ketene dimer and di- and/or triglycerides of fatty acids at ratios of 5-100 parts of ester to 100 parts of ketene dimer. Table 3 of this Japanese patent shows that the improvement obtained in sizing shortly after papermaking reaches a maximum at a ratio of 20 parts ester to 100 parts dimer. Higher ratios of ester to dimer caused a slight reduction in sizing obtained shortly after papermaking. Similarly the level of sizing obtained after one day reaches a maximum at the ratio of 20 parts of ester to 100 parts of dimer and thereafter decreases slightly at higher ratios.
It was surprisingly and unexpectedly found that the sizing effect obtained within a short time after papermaking with the compositions of the present invention was far greater than those obtained in Japanese Patent 57 112478 and the sizing effect obtained after one day was far higher than was being obtained using ketene dimer alone.
The actual amount of solids present in the dispersion may vary from about 3 to about 50% by weight, preferably from about 4 to about 40%, and most preferably from about 5 to about 35%.
Generally, the amount of sizing composition applied should be sufficient to result in paper having from about 0.01 to about 1% of ketene dimer based on the weight of dry paper.
Preferably, the sizing composition should result in from about 0.02 to about 0.6 and, most preferably, from about 0.04 to about 0.4% of ketene dimer based on the weight of dry paper.
This invention is illustrated by the following examples but is not limited by them. All parts and percentages are by weight unless otherwise specified.
The degree of sizing is measured by either a 1 minute Cobb Test using water (which is a standard internationally recognized test) or by the Hercules Sizing Test (H.S.T.). The Cobb Test measures water absorbed and higher sizing is shown by lower Cobb values.
In the HST, a sheet of sized paper is laid onto a solution containing by weight 1% of formic acid and 1.2% of Naphthol Green B. The reflectance of the paper is measured initially and is then monitored as it falls due to ink penetration into the paper. The HST time (in seconds) is the time taken for the reflectance to fall to 80% of its initial value. It can thus be seen that the larger the HST value, the better is the sizing.
EXAMPLES 1 TO 4 AND COMPARATIVE EXAMPLE 1
Glycerol tristearate/ketene dimer mixtures (made from a mixed feed of palmitic/stearic acids) having ratios of 0:1, 2:1, 3:1, 5:1 and 9:1 were prepared by melting and blending the two components. These mixtures were dispersed in aqueous dispersions of a waxy maize cationic starch having a degree of substitution of 0.035. These dispersions were added separately to paper stock consisting of 30 percent groundwood pulp, 35 percent hardwood pulp and 35 percent softwood pulp. The paper stock was used to make 65 grams per square meter (G.S.M.) paper sheets that were dried on a rotary cylinder drier. The sizing level of each sheet was determined by Cobb Test and by H.S.T. immediately off-drier and after one day of natural curing.
______________________________________ADDITIONGlycerol SIZINGTristea- Ketene Off-Drier Natural 1 DayEx. rate Dimer Cobb H.S.T. Cobb H.S.T.No. Percent.sup.1 Percent.sup.1 G.S.M. Seconds G.S.M. Seconds______________________________________C-1 -- 0.240 54 10 18.3 4411 0.240 0.120 59 18 20.4 2042 0.359 0.120 47 24 19.9 2843 0.600 0.120 40 92 19.6 2954 1.079 0.120 19 403 17.3 647______________________________________ .sup.1 Wt. % based upon weight of dried paper
These results show that the conjoint use of glycerol tristearate with 0.120 percent ketene dimer can result in:
(A) greatly improved off-drier sizing compared with the sizing of 0.240 percent ketene dimer alone;
(B) a level of sizing off-drier that is nearly 100 percent of the level of one day natural cured sizing achieved with 0.240 percent ketene dimer alone; and
(C) far higher levels of one day natural cured sizing compared with the one day natural cured sizing of 0.240 percent ketene dimer alone.
EXAMPLES 5 TO 8 AND COMPARATIVE EXAMPLE 2
Example 1 was repeated using a potato cationic starch having a degree of substitution of 0.043 and the following results were obtained:
______________________________________ADDITIONGlycerol Ketene SIZING H.S.T. SECONDSEx. Tristearate Dimer NaturalNo. Percent Percent Off-Drier 1 Day______________________________________C-2 -- 0.18 42.0 325.05 0.225 0.045 116.0 288.06 0.225 0.09 191.0 426.07 0.30 0.09 219.0 363.58 0.45 0.09 227.5 394.0______________________________________
This experiment shows again that the conjoint use of glycerol tristearate with a ketene dimer can greatly increase the off-drier sizing and can increase the level of one day natural cured sizing compared with the off-drier and one day natural cured sizing achieved with twice the added amount of ketene dimer alone.
EXAMPLE 9 AND COMPARATIVE EXAMPLE 3
500 g. of a hot dispersion containing 15 g. of a ketene dimer prepared from mixed palmitic/stearic acids, 15 g. of a waxy maize cationic starch having a degree of substitution of 0.035 and 0.35 g. of sodium lignin sulphonate were prepared. This was repeated using 75 g. of glycerol tristearate in place of the 15 g. of ketene dimer.
These two hot dispersions were mixed. The mixture was cooled and acidified to pH 4.3.
This mixture was tested in a paper system of 35 percent groundwood pulp and 65 percent cellulose pulp with the following results:
______________________________________ADDITIONGlycerol Ketene SIZING H.S.T. SECONDSEx. Tristearate Dimer NaturalNo. Percent Percent Off-Drier 1 Day______________________________________C-3 -- 0.18 54.1 305.09 0.225 0.045 170.0 310.0______________________________________
These results show that the conjoint use of glycerol tristearate with 0.045 percent ketene dimer results in greatly improved off-drier sizing compared with the use of 0.18 percent ketene dimer alone.
EXAMPLE 10
Following the procedure of Example 1, glycerol tristearate and ketene dimer were melted and blended in the amounts indicated in the Table below. These mixtures were stabilized in POLYMIN SK, an aqueous solution of highly cationic polyethyleneimine having a total solids of 25% by weight sold by BASF, to yield stable aqueous dispersions. These dispersions were tested as in Example 1 and the results are summarized in the following Table.
______________________________________ Glycerol Ketene NaturalEx. Tristearate Dimer Off Drier 1 DayNo. Percent Percent HST-Seconds HST-Seconds______________________________________C-4 -- 0.3 105 42810 0.55 0.05 838 1200C-5 -- 0.18 65 31311 0.3 0.06 116 393______________________________________
These results show again that the conjoint use of glycerol tristearate and ketene dimer in the manner of this invention results in higher levels of sizing, both off-drier and after natural curing for 1 day, when compared with the levels of sizing achieved with far larger amounts of ketene dimer alone.
This example also shows that the effects and benefits of this invention are independent of the stabilizing system used. It is necessary to make stable dispersion but this may be achieved by the use of conventional products and techniques. | Compositions of ketene dimer and nonreactive hydrophobe compound and method for internally sizing paper therewith are provided, wherein the melting point of said hydrophobe compound is higher than the melting point of the ketene dimer. | 3 |
BACKGROUND OF THE INVENTION
[1] 1. 1. Field of the Invention
[2] 2. The present invention relates to a damping force generating mechanism for generating a damping force by pressing an elastic body.
[3] 3. 2. Description of the Background Art
[4] 4. A damping force generating mechanism is used for various portions required for absorbing vibration, for example, used for a so-called bottom link type suspension of a motorcycle in which a front wheel is suspended from lower end portions of a front fork through links. A general example of such a bottom link type suspension is shown in FIG. 16 (see Japanese Patent Laid-open No. Sho 62-187608).
[5] 5. Referring to FIG. 16, there is shown a scooter type motorcycle 01 . A steering shaft 03 is turnably fitted in a head pipe 02 . A pair of right and left front forked portions 04 are integrally mounted on the lower end of the steering shaft 03 . A front wheel 06 is suspended from the lower ends of the front forked portions 04 through rocking arms 05 as link members.
[6] 6. With respect to the rocking arm 05 , the base end thereof is pivotably supported on the lower end portion of the front forked portion 04 , and the free end portion thereof rotatably supports the front wheel 06 . A suspension spring 07 is interposed between the upper portion of the front forked portion 04 and an approximately central portion of the rocking arm 05 .
[7] 7. A shock load applied to the front wheel from irregularities on the ground is damped by the suspension springs 07 . However, when a shock load is applied with an abrupt shock load, the suspension springs are largely rebounded after being contracted once.
[8] 8. In an example described in Japanese Patent Publication No. Sho 57-49432, as shown in FIG. 17, a front end of a link 012 is pivotably supported on the lower end portion of a front forked portion 011 containing a hydraulic damping mechanism. A front wheel 013 is rotatably supported on a central portion of the link 012 . A subcushion unit 14 is interposed between the rear end of the link 012 and the central portion of the front forked portion 011 .
[9] 9. The subcushion unit 014 includes a cylindrical main body 015 pivotably mounted on the front forked portion 011 . A piston 016 is slidably inserted in the cylindrical main body 015 and is connected to a leading end of a rod 017 pivotably mounted on the link 012 . A cushion rubber 018 utilized as a damping member is inserted in the cylindrical main body 015 in such a manner as to be mounted on the upper surface of the piston 016 . A stopper rubber 019 utilized as a stopper member is inserted in the cylindrical main body 015 in such a manner as to be mounted on the lower surface of the piston 016 .
[10] 10. The subcushion unit 014 thus generates a compression side damping force by the cushion rubber 018 , and also generates a tensile side damping force by the stopper rubber 019 . Consequently, the subcushion unit 014 can suppress both the bound and rebound of the front wheel 013 .
[11] 11. The above subcushion unit 014 , however, has a disadvantage. Since the piston 016 is slid in the cylindrical main body 015 , and the cushion rubber 018 and the stopper rubber 019 are separately provided on the upper and lower surfaces of the piston 016 , the mechanism is complicated in structure, being heavy and expensive.
SUMMARY OF THE INVENTION
[12] 12. In view of the foregoing, an object of the present invention is to provide an inexpensive damping, force generating mechanism capable of generating both a compression side damping force and a tensile side damping force with a simple, lightweight structure.
[13] 13. To achieve the above object, a damping force generating mechanism is provided including an elastic body which generates a damping force when being pressed, and an internal pressure generating member inserted in the elastic body which resists the pressing force.
[14] 14. With this configuration, the mechanism enables a large displacement due to bending deformation of the elastic body and thereby it enables absorption of a sufficient energy. The creep generated upon bending deformation of the elastic body can be reduced by repulsion of the internal pressure generating member inserted in the elastic body accompanied by compressed deformation of the internal pressure generating member. Accordingly, a damping force generating mechanism can be obtained which is capable of reducing the characteristic change due to permanent set. The restoring ability after release of a load is also excellent due to repulsion of the internal pressure generating member.
[15] 15. The internal pressure generating member may comprise a spring member. With this configuration, the creep of the elastic body is reduced by repulsion of the spring member accompanied by the compression thereof. Accordingly, it is possible to make the characteristic change due to permanent set smaller and to enhance the restoring ability.
[16] 16. The internal pressure generating member may comprise a partitioned chamber containing a compressive gas or liquid. With this configuration, the creep of the elastic member is reduced by repulsion of a compressive gas or liquid compressed and deformed together with the partitioned chamber. Accordingly, it is possible to make the characteristic change due to permanent set smaller and to enhance the restoring ability.
[17] 17. The internal pressure generating member may comprise an elastic organic material. The internal pressure generating member, which is made from the organic material, can be easily molded in a shape most suitable for the application. The organic material may have a hollow portion. With this configuration, when the organic material is compressed, a specific repulsive force can be obtained by the presence of the hollow portion. The organic material may be a polyester-urethane based material. With this configuration, it is possible to obtain a specific repulsive force by a large elasticity of a polyester-urethane based material.
[18] 18. To further achieve the object of the invention, a damping force generating mechanism is provided which includes an elastic body which generates a damping force when being pressed, and a restricting wall for suppressing expansion of the elastic body generated in the direction perpendicular to the pressing direction of the elastic body.
[19] 19. When the elastic body is pressed, the expansion of the elastic body in the direction perpendicular to the pressing direction is restricted by the restricting wall. As such, the force of the elastic body applied to the restricting wall becomes larger and the sliding resistance of the elastic body is increased. As a result, a desirable relationship of load to displacement can be easily obtained by the action of the sliding resistance of the elastic body in addition to the elastic characteristic of the elastic body.
[20] 20. The elastic body may be separated from the restricting wall with a gap therebetween at the beginning of pressing of the elastic body, and brought into contact with the restricting wall with progressive pressing of the elastic body.
[21] 21. At the beginning of the pressing, since the elastic body is not brought into contact with the restricting wall due to the gap therebetween, the load is gradually increased with an increase in displacement only by the elastic characteristic of the elastic body. However, as the elastic body is pressed to a state where the elastic body is in contact with the restricting wall, the load is rapidly increased with an increase in displacement by a combination of the sliding resistance of the elastic body and the elastic characteristics of the elastic body. As a result, a desirable relationship of the load to the displacement can be obtained.
[22] 22. The contact area of the elastic body with the restricting wall may be enlarged with further progress of pressing of the elastic body. With this configuration, after the pressed elastic body is brought into contact with the restricting wall, the contact area of the elastic body with the restricting wall is enlarged and thereby the sliding resistance of the elastic body is increased. As a result, a desirable smooth relationship of the increased load to the increased displacement can be obtained.
[23] 23. The elastic body may have a hollow portion opened to the restricting wall side, with an intermediate elastic body inserted in the hollow portion. Therefore, when the elastic body is pressed, the intermediate elastic body is compressed, being swelled out of the opening of the hollow portion, and is brought in press-contact with the restricting wall.
[24] 24. When the elastic body is pressed, sliding resistance is generated due to the contact of the elastic body with the restricting wall in addition to the elastic characteristics of the elastic body, and also the sliding resistance of the intermediate elastic body due to the pressing contact of the restricting wall with the intermediate elastic body compressed and swelled from the opening of the hollow portion. As a result, a desirable relationship of the load to the displacement of the elastic body can be easily obtained.
[25] 25. To further achieve the object of the invention, a damping force generating mechanism is provided which includes an elastic body which generates a damping force when being pressed, a hollow portion opened in the elastic body in the direction perpendicular to the pressing direction, an intermediate elastic body inserted in the hollow portion, and a restricting wall provided opposite to the opening of the hollow portion. Thus, when the elastic body is pressed, the intermediate elastic body is compressed, being swelled out of the opening of the hollow portion, and is brought into pressing contact with the restricting wall.
[26] 26. At the beginning of the pressing of the elastic body, elastic characteristics of the elastic body and the intermediate elastic body are generated. However, as the pressing of the elastic body proceeds, the intermediate elastic body is compressed, being swelled out of the hollow portion of the elastic body, and is brought into contact with the restricting wall. Thus, sliding resistance of the intermediate elastic body is generated. As a result, a desirable relationship of the load to the displacement of the elastic body can be easily obtained.
[27] 27. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[28] 28. The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[29] 29.FIG. 1 is a side view of a scooter-type motorcycle including a wheel suspension to which a damping force generating mechanism according to a first embodiment is applied, with parts partially omitted;
[30] 30.FIG. 2 is a side view of a front forked portion and the vicinity thereof;
[31] 31.FIG. 3 is a sectional view of essential portions of the front fork portion;
[32] 32.FIG. 4 is a sectional view taken on line IV-IV of FIG. 3;
[33] 33.FIG. 5 is an exploded view in perspective of a case, lid member and locking piece;
[34] 34.FIG. 6 is a sectional view of an elastic rubber body;
[35] 35.FIG. 7 is a view seen in the direction shown by arrow VII of FIG. 6;
[36] 36.FIG. 8 is a view seen in the direction shown by arrow VIII of FIG. 6;
[37] 37.FIG. 9 is a view seen in the direction shown by arrow IX of FIG. 6;
[38] 38.FIG. 10 is a graph showing an elastic characteristic of the elastic rubber body;
[39] 39.FIG. 11 is a sectional view of essential portions of a front forked portion according to a modification of the first embodiment;
[40] 40.FIG. 12 is a view seen from in the direction shown by arrow XII of FIG. 11, showing a locking portion of a lever with an elastic rubber body;
[41] 41.FIG. 13 is a view showing another example of the locking portion of the lever with the elastic rubber body shown in FIG. 12;
[42] 42.FIG. 14 is a sectional view of essential portions of a front forked portion according to another modification of the first embodiment;
[43] 43.FIG. 15 is a view seen from in the direction shown by arrow XV of FIG. 14, showing a locking portion of a lever with an elastic rubber body;
[44] 44.FIG. 16 is a view showing a motorcycle including a prior art front wheel suspension;
[45] 45.FIG. 17 is a sectional view showing another prior art front wheel suspension;
[46] 46.FIG. 18 is a side view of an elastic body containing a spring member according to a second embodiment;
[47] 47.FIG. 19 is a top view of the elastic body shown in FIG. 18;
[48] 48.FIG. 20 is a sectional view showing a damping force generating mechanism of a wheel suspension;
[49] 49.FIG. 21 is a sectional view showing the damping force generating mechanism of FIG. 20, which is in a state different from that in FIG. 20;
[50] 50.FIG. 22 is a graph showing an elastic characteristic of the damping force generating mechanism shown in FIG. 20;
[51] 51.FIG. 23 is a graph showing a change in creep amount with an elapsed time for the damping force generating mechanism shown in FIG. 20;
[52] 52.FIG. 24 is a sectional view of essential portions of a wheel suspension using a damping force generating mechanism according a modification of the second embodiment;
[53] 53.FIG. 25 is a sectional view of the essential portions of the damping force generating mechanism of FIG. 24, which is in a state different from that shown in FIG. 24;
[54] 54.FIG. 26 is a view showing a damping force generating mechanism of a wheel suspension according to a third embodiment;
[55] 55.FIG. 27 is a sectional view taken on line XXXVII-XXXVII of FIG. 26;
[56] 56.FIG. 28 is a sectional view showing the damping force generating mechanism of the wheel suspension of FIG. 26, which is in a state different from that in FIG. 26;
[57] 57.FIG. 29 is a sectional view taken on line XXIX-XXIX of FIG. 28;
[58] 58.FIG. 30 is a graph showing an elastic characteristic of the damping force generating mechanism shown in FIG. 26;
[59] 59.FIG. 31 is a sectional view of essential portions of a wheel suspension using a damping force generating mechanism according to a modification of the third embodiment;
[60] 60.FIG. 32 is a transverse sectional view taken on line XXXII-XXXII of FIG. 31;
[61] 61.FIG. 33 is a sectional view of the damping force generating mechanism of FIG. 31, which is in a state different from that in FIG. 31;
[62] 62.FIG. 34 is a sectional view of essential portions of a wheel suspension using a damping force generating mechanism according to another modification of the third embodiment; and
[63] 63.FIG. 35 is a sectional view of the damping force generating mechanism of FIG. 34, which is in a state different from that in FIG. 34.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[64] 64. A damping force generating mechanism according to a first embodiment is described with reference to FIGS. 1 to 10 . FIG. 1 is a side view of a scooter-type motorcycle 1 including a wheel suspension to which a damping force generating mechanism in the embodiment is applied, with parts partially omitted.
[65] 65. A low level floor 4 is formed between a front portion 2 and a rear portion 3 of the body. A down frame 6 extends downwardly from a head pipe 5 provided on the front portion 2 of the body, being curved rearwardly from the lower end portion, and is integrated with the floor 4 .
[66] 66. A steering shaft 7 is turnably fitted to the head pipe 5 . A pair of right and left front forked portions 8 are integrally mounted on the lower end of the steering shaft 7 , and they extend downwardly therefrom. A rocking arm 9 as a link member is pivotably supported at the lower end of each front forked portion 8 by means of a pivot arm bolt 11 . A front wheel 13 is rotatably supported by the free ends of the rocking arms 9 through a front axle 12 .
[67] 67. The front forked portion 8 is U-shaped in cross section with a front wall and both side walls. The right and left side walls at the lower end portion of the front forked portion 8 have bolt holes. A bush 14 provided in a base end pivot portion 9 a of the rocking arm 9 is fitted between both side walls of the front forked portion 8 at a position corresponding to the bolt holes. The bush 14 is rotatably supported by a pivot arm bolt 11 passing through the bush 14 and the bolt holes of the side walls of the front forked portion 8 . Each side of the base end pivot portion 9 a of the rocking arm 9 is formed in a cylindrical shape having an enlarged diameter. A plate-like lever 10 is integrated with the outer peripheral surface of the cylindrical side portion of the base end pivot portion 9 a and extends therefrom in the radial direction.
[68] 68. In a state in which the rocking arm 9 extends rearwardly from the base end pivot portion 9 a , the lever 10 extends obliquely, upward at an angle of about 60 degrees relative to the rocking arm 9 . That is, it extends between the front forked portion 8 and the rocking arm 9 .
[69] 69. A fan-shaped case 15 is fixedly inserted in the front fork portion 8 at a position adjacent to the upper portion of the base end pivot portion 9 a of the rocking arm 9 .
[70] 70. As shown in FIG. 5, the case 15 is formed into a box-like shape having a fan-shaped side wall 15 a , an outer peripheral wall 15 b , a front wall 15 c and a rear wall 15 d . A slot 15 e is formed in the side wall 15 a along the front edge, and three circular holes 15 f are formed in upper and lower ends of the front wall 15 c and in the upper end of the rear wall 15 d in such a manner as to pass therethrough in the right and left direction, that is, in the width direction.
[71] 71. As shown in FIG. 5, there is provided a plate-like lid member 16 opposed to the side wall 15 a for blocking the opening of the case 15 . The lid member 16 , which is formed into the same fan-shape as that of the side wall 15 a , has a slot 16 e corresponding to the slot 15 e , and three circular holes 16 f corresponding to the circular holes 15 f.
[72] 72. A locking piece 17 is locked in the slots 15 e and 16 e opposed to each other. In a state in which the lid member 16 is fitted to the ease 15 , only the lower side of the case 15 is opened.
[73] 73. An elastic rubber body 20 is contained in the case 15 covered with the lid member 16 . The elastic rubber body 20 is formed into a shape shown in FIGS. 6 to 9 . That is, the elastic rubber body 20 has a fan-shaped cross section similar to but smaller than that of the inner space of the case 15 , and also has a large projection 20 a projecting from the rear surface of the fan-shaped cross section. In addition, corners at upper and lower ends of the front side of the fan-shaped cross section are slightly cut off.
[74] 74. A circular hole 20 b and a large-sized irregular rectangular hole 20 c are formed fore and aft in the elastic rubber body 20 having the above contour in such a manner as to pass through the elastic rubber body 20 in the width direction. Slots 20 e and 20 f are also formed in the elastic rubber body 20 . The slot 20 e (corresponding to the slot 15 e of the above case 15 ) is disposed between the circular hole 20 b and the front surface of the elastic rubber body 20 in such a manner as to extend in parallel to the front surface. The slot 20 f passes through a base portion of the projection 20 a in parallel to the rear surface of the elastic rubber body 20 .
[75] 75. The elastic rubber body 20 exhibits a hysteresis characteristic of compression and tensile actions, and it has both elastic and damper functions.
[76] 76. The elastic rubber body 20 , case 15 , and the like are assembled as follows. The lever 10 integrated with the rocking arm 9 is made to pass through the slot 20 f formed in the base portion of the projection 20 a of the elastic rubber body 20 , to be thus mounted in the elastic rubber body 20 . The case 15 covers the elastic rubber body 20 from the left side, and the lid member 16 closes the case 15 from the right side. Thus, the lever 10 is in a state being inserted in the case 15 through the lower opening of the case 15 .
[77] 77. The locking piece 17 is made to pass through the slot 15 e of the case 15 , the slot 20 e of the elastic rubber body 20 , and the slot 16 e of the lid member 16 , and hence to be fitted in the slots 15 e , 20 e and 16 e . Then, a screw 25 is threaded into the circular hole 15 f formed in the upper end portion of the rear wall 15 d of the case 15 and in the circular hole 16 f of the lid member 16 corresponding to the circular hole 15 f , to thus integrally fix the case 15 to the lid member 16 .
[78] 78. The case 15 covered with the lid member 20 , which is mounted to the lever 10 through the elastic rubber body 20 , is inserted into the recess on the back side of the front forked portion 8 to the extent that the front wall 15 c of the case 15 is brought into contact with the bottom of the recess.
[79] 79. Each of the right and left side walls of the front fork portion 8 has circular holes at specific upper and lower positions along the bottom. The circular holes 15 f and 16 f of the case 15 and the lid member 16 are aligned with the above circular holes, and bolts 26 are made to pass through these circular holes and are attached to nuts. Accordingly, the case 15 and the lid member 16 are co-fastened to the front forked portion 8 with the bolts 26 , to be thus fixed thereto.
[80] 80. In the assembled state, the elastic rubber body 20 is disposed in the case 15 as shown in FIGS. 3 and 4. That is, with respect to the elastic rubber body 20 , the front end portion is positioned in a state being locked by the locking piece 17 , the rear portion is held by the lever 10 inserted in the slot 20 f , and the projection 20 a projecting rearward is allowed to be brought in contact with the rear wall 15 d of the case 15 .
[81] 81. In this way, the front wheel suspension in this embodiment has a very simple structure that the elastic rubber 20 is interposed between the front forked portion 8 and the lever 10 in a state in which the front portion thereof is locked by the locking piece 17 and the rear portion thereof is locked by the lever 10 .
[82] 82. When the front wheel 13 is applied with a shock generated by irregularities of the ground and the rocking arm 9 is rocked, the positional states of the rocking arm 9 and the lever 10 integrated with the rocking arm 9 are changed from states indicated by a solid line of FIG. 3 to states indicated by a two-dot chain line. As a result, the lever 10 compresses the elastic rubber body 20 in the forward direction, that is, on the front forked portion 8 side, and elastically deforms it, to thereby generates a compression side damping force.
[83] 83. In this case, the elastic rubber body 20 has a progressive elastic characteristic shown in FIG. 10 in which the increasing ratio of a load to a displacement is large in a large displacement region as compared with a small displacement region. Specifically, in a small displacement region that only the irregular rectangular hole 20 c of the elastic rubber body 20 is deformed, a compressive stress is moderately generated to the displacement, but in a large displacement region that not only the irregular rectangular hole 20 c but also the circular hole 20 b are deformed, the compressive stress is rapidly increased with the displacement.
[84] 84. On the other hand, when the rocking arm 9 and the lever 10 are reversely rocked, the main body of the elastic rubber body 20 generates a tensile damping force, and simultaneously the projection 20 a is pressed and compressed by the rear wall 15 d of the case 15 , thus acting as a rebound stopper.
[85] 85. Accordingly, while the front wheel suspension in this embodiment has the simple structure in which the elastic rubber body 20 is interposed between the front fork portion 8 and the lever 10 , it exhibits a desirable damping effect due to the function of the elastic rubber body 20 generating both a compression side damping force and a tensile side damping force thereby effectively absorbing shock applied from the ground to the front wheel 13 .
[86] 86. In this way, the front wheel suspension in this embodiment does not require a pivot for supporting the elastic rubber body 20 , and has no sliding portion for a piston or the like, so that it can obtain a stable damping characteristic without the occurrence of any sliding friction, thereby enhancing the durability with a simple, lightweight, and inexpensive structure.
[87] 87. It is to be noted that it becomes possible to obtain various other elastic characteristics of the elastic rubber body 20 by changing the shapes of the circular hole 20 b and the irregular rectangular hole 20 c of the elastic rubber body 20 , and hence to easily provide an elastic body most suitable for each kind of vehicle.
[88] 88. Next, the structure of a front wheel suspension disposed at the lower end portion of a front forked portion 40 according to a modification of the first embodiment will be described with reference to FIGS. 11 and 12. This modification has the same basic structure as that of the first embodiment, except for slightly changed shapes of the parts. A base end pivot portion 41 a of a rocking arm 41 is rockably supported, by means of a pivot arm bolt 42 , at the lower end of the front forked portion 40 . The rocking arm 41 has a plate-like lever 43 extending from the base end pivot arm portion 41 a in the radial direction. A fan-shaped case 44 adjacent to the upper side of the base end pivot portion 41 a of the rocking arm 41 is fixedly fitted in the front forked portion 40 .
[89] 89. An elastic rubber body 45 , which has throughholes 45 b and 45 c passing through the elastic rubber body 45 in the width direction, is fitted in the case 44 . A locking piece 46 passes through the front portion of the elastic rubber body 45 and locks it. A lever 43 is inserted in a slot 45 d formed in the rear portion of the elastic rubber body 45 , and a projection 45 a projecting rearwardly from the rear portion is allowed to be brought into contact with the rear wall of the case 44 .
[90] 90. The lever 43 has a swelled portion 43 b , a stepped portion 43 c , and a flange portion 43 d . As shown in FIG. 12, the swelled portion 43 b is swelled right and left, that is, in the width direction on the base end side from a locking portion 43 a to be locked with the elastic rubber body 45 , and the stepped portion 43 c is formed at the boundary between the locking portion 43 a and swelled portion 43 b . The flange portion 43 d projects upward from the leading end of the lever 43 , as shown in FIG. 11.
[91] 91. The lever 43 passes through the slot 45 d of the elastic rubber body 45 , and the elastic rubber body 45 is locked with the locking piece 43 a . At the same time, the elastic rubber body 45 is held between the stepped portion 43 c and the flange portion 43 d of the lever 43 . The sliding motion of the elastic rubber body 45 relative to the lever 43 is thus restricted by the stepped portion 43 c and the flange portion 43 d of the lever 43 . This allows the elastic rubber body 45 to effectively generate a damping force.
[92] 92.FIG. 13 shows another example of the lever. A lever 50 has a fitting portion 50 c on the base end side of a locking portion 50 a at the boundary between the locking portion 50 a and a swelled portion 50 b , and also has on the leading end side a flange portion 50 d projecting in the right and left direction. An elastic rubber body 51 is held between the fitting portion 50 c and the flange portion 50 d of the lever 50 , so that the sliding motion of the elastic rubber body 45 relative to the lever 43 is restricted.
[93] 93. Next, another modification of the first embodiment will be described with reference to FIGS. 14 and 15. The modification, which also concerns a front wheel suspension provided on the lower end portion of a front forked portion 60 , is substantially similar to the above modification shown in FIGS. 11 and 12 in terms of shapes of a rocking arm 61 , a lever 63 , a case 64 , and an elastic rubber body 65 , but is different therefrom in terms of the structure of restricting the sliding motion of the elastic rubber body 65 relative to the lever 63 .
[94] 94. A circular hole 63 b is formed in a plate-like locking portion 63 a of the lever 63 , and a circular hole 65 e corresponding to the circular hole 63 b is formed in the elastic rubber body 65 . The circular hole 65 e is continuous to a slot 65 d formed in a rear projection 65 a , and further to a recess formed in the opposed portion, to the slot 65 d , of the rear portion of the elastic rubber body 65 . A knock pin 66 is inserted in the circular hole 63 b of the lever 63 and the circular hole 65 e of the elastic rubber body 65 .
[95] 95. Accordingly, the sliding motion of the elastic rubber body 65 relative to the lever 63 is restricted by the knock pin 66 , so that the elastic rubber body 65 is allowed to effectively generate a damping force. The lever 63 , which has no flange portion at the leading end thereof, is easily inserted in the slot 65 d of the elastic rubber body 65 upon assembly.
[96] 96. Although description has been made by example of the front wheel suspension for a motorcycle in the above first embodiment and modifications thereof, the present invention can be applied to a rear wheel suspension, and used as a damper mechanism for a power transmission of an engine and a damper mechanism for a cam chain tensioner.
[97] 97. Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 18 to 23 . In the second embodiment also concerning a front suspension mechanism as in the first embodiment, parts corresponding to those in the first embodiment are indicated by the same reference characters.
[98] 98.FIGS. 18 and 19 shows the second embodiment, in which four holes having different shapes and passing through an elastic rubber body 120 i in the width direction are formed in the elastic rubber body 120 . The four holes, an elliptic hole 120 b (corresponding to the slot 15 e of the case 15 in the previous embodiment), an irregularly elliptic hole 120 c , a developed fan-shaped hole 120 d , and a contracted fan-shaped hole 120 e are arranged from the front side in this order. Further, a through-slot 120 f is formed in the base portion of a projection 120 a along the rear surface of the elastic rubber body 120 .
[99] 99. A metal spring member 121 as an internal pressure generating member is inserted in the developed fan-shaped hole 120 d . The spring member 121 is composed of radially extending plate springs arranged in a fan-shape corresponding to the internal space of the developed fan-shaped hole 120 d . The spring member 121 is made repulsive against a compression side pressing force while generating an internal pressure.
[100] 100. The elastic rubber body 120 is contained in a case 15 in a state shown in FIG. 20. That is, with respect to the elastic rubber body 120 , the front end portion is locked and positioned by a locking piece 17 passing through the front portion. A lever 10 is inserted in the slot 120 f , and a projection 120 a projecting rearwardly is brought into contact with a rear wall 15 d of the case 15 .
[101] 101. As described above, the front wheel suspension in this embodiment has a simple structure in which the elastic rubber body 120 containing the spring member 121 is interposed between a front forked portion 8 and the lever 10 in the state that the front portion of the elastic rubber body 120 is locked with the locking piece 17 and the rear portion of the elastic rubber body 120 is locked with the lever 10 .
[102] 102. When a front wheel 13 is applied with shock generated by irregularities of the ground or a load upon braking and thereby the rocking arm 9 is rocked, the rocking arm 9 and the lever 10 integrated with the rocking arm 9 are rocked from a state shown in FIG. 20 to a state shown in FIG. 21. The lever 10 thus presses the elastic rubber body 120 forward onto the front forked portion 8 , and it elastically deforms the elastic rubber body 120 . As a result, the spring member 121 inserted in the elastic rubber body 120 is compressed and is made repulsive while generating an internal pressure.
[103] 103. In this case, the elastic rubber body 120 has an elastic characteristic shown in FIG. 22, in which the displacement of the elastic rubber body 120 is increased from the initial state having an initial strain to a sufficiently large value by increasing the applied load, and then the displacement is decreased along the hysteresis curve by decreasing the load and finally it becomes zero when the load reaches zero. Accordingly, the elastic rubber body 120 can ensure a large displacement and obtain sufficient energy absorption, and further it improves the initial strain.
[104] 104. The result of an experiment of examining the generation amount of creep of the elastic rubber body 120 containing the spring member 121 is shown in FIG. 23. In FIG. 23, an example of using the prior art elastic body not containing the spring member is shown by a broken line, and the example using the elastic rubber body 120 containing the spring member 121 is shown by a solid line. As is apparent from this figure, the creep amount of the elastic rubber body 120 is significantly reduced as compared with the prior art elastic body.
[105] 105. The characteristic change of the elastic rubber body 120 due to fatigue is thus small. Further, the elastic rubber body 120 is excellent in restoring ability after release of a load. That is, while the prior art elastic body causes approximately 100% of the permanent strain, the elastic rubber body 120 only causes approximately 40% of the permanent strain.
[106] 106. A modification of the second embodiment will be described with reference to FIGS. 24 and 25. The modification is the same as the second embodiment, except for an elastic body 130 and an internal pressure generating member 131 inserted in the elastic body 130 . In this modification, parts corresponding to those in the second embodiment are indicated by the same characters.
[107] 107. The elastic body 130 is made from polyester elastomer and has an outer shape being substantially the same as that of the elastic body 120 in the second embodiment. Further, an elliptic hole 130 b , and an irregularly elliptic hole 130 c formed in the elastic body 130 , and a slot 130 f passing through the elastic body 130 along the base portion of a rear projection 130 a are formed in the same shapes as those of the corresponding ones in the second embodiment. In this modification, however, the developed fan-shaped hole 120 d and the contracted fan-shaped hole 120 e are omitted, and instead, an irregular circular hole 130 d is formed and an internal pressure generating member 131 is inserted in the irregular circular hole 130 d.
[108] 108. The internal pressure generating member 131 is made from polyester-urethane being softer and more elastic than the elastic body 130 and is formed in a cylindrical shape having a specific wall thickness. When the elastic body 130 is applied with a load and a rocking arm 9 is rocked, the rocking arm 9 and a lever 10 integrated with the rocking arm 9 are rocked from a state shown in FIG. 24 to a state shown in FIG. 25, so that the lever 10 presses the elastic body 130 forward to a front forked portion 8 and thereby it elastically deforms the elastic body 130 . In such a state, the internal pressure generating member 131 inserted in the elastic body 130 is compressed and is made repulsive while generating an internal pressure.
[109] 109. The elastic body 130 can ensure a large displacement and obtain a sufficient energy absorption, and it is significantly reduced in creep by the effect of the internal pressure generating member 131 and thereby it is small in characteristic change due to fatigue. Further, the elastic body 130 is excellent in restoring ability after release of a load.
[110] 110. In addition, the elastic body may be made from rubber in place of polyester-urethane. Also, with respect to the internal pressure generating member 131 made from polyester-urethane, the cylindrical hollow type may be replaced with a solid type. And, a different elastic substance may be inserted in the hollow portion of the elastic body.
[111] 111. The internal pressure generating member may be made from an organic material having a specific elasticity, in place of polyester-urethane. In this case, the organic material can be easily molded into a shape most effective to the application use of the elastic body.
[112] 112. Additionally, it may be considered to form an enclosed partition chamber containing a compressive gas or liquid in the elastic body. When the elastic body is pressed and deformed, the gas or liquid contained in the partition chamber is compressed to generate an internal pressure. Such an elastic body is allowed to be significantly reduced in creep and hence to be reduced in characteristic change, and also to enhance the restoring ability after release of a load.
[113] 113. A third embodiment of the present invention will be described with reference to FIGS. 26 to 30 . In the third embodiment also concerning a front wheel suspension as in the previous embodiments, parts corresponding to those in the previous embodiments are indicated by the same characters. FIG. 27 shows the third embodiment using an elastic body 220 made from polyester elastomer. The elastic body 220 is formed in a shape being substantially similar to but smaller than that of the inner space of the case 15 . The elastic body 220 has right and left side surfaces 220 R and 220 L which are substantially parallel to each other and are slightly curved in such a manner as to be gradually close to each other in the direction from the front side to the rear side, and it has a large projection 220 a projecting from the rear portion thereof.
[114] 114. Three holes of different shapes are formed in the elastic rubber body 220 having such a contour. These holes, an elliptic hole 220 b (corresponding to the elliptic hole 15 e of the case 15 in the previous embodiment), an irregular elliptic hole 220 c , and an irregular elliptic hole 220 d are arranged from the front side in this order. Further, a slot hole 220 e is formed which passes through the base portion of the projection 220 a along the rear surface of the elastic rubber body 220 .
[115] 115. As shown in FIG. 27, the right and left side surfaces 220 R and 220 L of the elastic body 220 contained in the case 15 are respectively brought into contact with a side wall 15 a of the case 15 and a lid member 16 on the front side of the elastic body 220 , that is, on the side locked with a locking piece 17 , and they are gradually separated from the side wall 15 a of the case 15 and the lid member 16 with the increased gap as nearing the rear side. In this way, the front wheel suspension in this embodiment has a simple structure in which the elastic body 220 is interposed between a front forked portion 8 and a lever 10 in such a manner that the front portion thereof is locked with the locking piece 17 and the rear portion thereof is locked with the lever 10 .
[116] 116. When a front wheel 13 is applied with a shock generated by irregularities on the ground or a load upon braking and thereby the rocking arm 9 is rocked, the rocking arm 9 and the lever 10 integrated with the rocking arm 9 are rocked as shown in FIGS. 28 and 29, so that the lever 10 presses the elastic body 220 forward to the front forked portion 8 and thereby it elastically deforms the elastic body 220 .
[117] 117. When being pressed, the elastic body 220 is expanded in the direction perpendicular to the pressing direction, that is, in the vertical direction and also in the right and left direction. The expansion of the elastic body 220 in the right and left direction causes the right and left side surfaces 220 R and 220 L to be swelled and to be respectively brought in contact with the side wall 15 a of the case 15 and the lid member 16 . Consequently, the expansion of the elastic body 220 is suppressed by the above contact, and as the pressing of the elastic body 220 proceeds, the contact area thereof is increased, so that the sliding resistance of the elastic body 220 at the contact surface of the right and left side surfaces 220 R and 220 L with the side wall 15 a of the case 15 and the lid member 16 is increased. Thus, as the displacement (stroke) of the elastic body 220 is increased, the sliding resistance as well as the elastic force of the elastic body 220 is progressively increased.
[118] 118. The stroke-load characteristic in this embodiment is shown by a solid line of FIG. 30. The stroke-load characteristic forms a hysteresis curve. At the beginning of the motion of the elastic body 220 , that is, when the stroke is small, the sliding resistance of the elastic body 220 is small and thereby the gradient of the curve of the load to the stroke is moderate. When the stroke becomes relatively large, the sliding resistance is added to the elastic force, and thereby the gradient of the curve is increased. When the stroke becomes very large, the gradient is further increased by the action of the progressively increased sliding resistance. In this way, the front wheel suspension in this embodiment exhibits the desirable damping effect.
[119] 119. The action of the sliding resistance can be easily adjusted by changing the shapes of the right and left side surfaces 220 R and 220 L of the elastic body 220 , to thereby easily obtain a specific stroke-load characteristic.
[120] 120. A modification of the third embodiment will be described with reference to FIGS. 31 to 33 . In the modification also concerning a front wheel suspension as in the third embodiment, parts corresponding to those in the third embodiment are indicated by the same characters. An elastic body 230 is formed into the same shape as that of the elastic body 220 in the third embodiment. However, in the elastic body 230 , an intermediate elastic body 235 is inserted in an irregular elliptic hole 230 C as one of hollow portions. The intermediate elastic body 235 is made from a material smaller in elastic modulus than the elastic body 230 , that is, deformable easier than the elastic body 230 .
[121] 121. In a state before the rocking arm 9 is rocked (see FIGS. 31 and 32), as shown in FIG. 32, the intermediate elastic body 235 is fitted in the irregular elliptic hole 230 c , that is, not swelled from the right and left openings of the irregular elliptic hole 230 c.
[122] 122. When the front wheel 13 is applied to shock generated by irregularities on the ground and the rocking arm 9 is rocked, the elastic body 230 is pressed and elastically deformed, so that the irregular elliptic hole 230 c is also compressed in the pressing direction and it compresses the intermediate elastic body 235 contained in the hole 230 c . At this time, the intermediate elastic body 235 made from a soft material is easily deformed, being expanded in the direction perpendicular to the compression direction, and is swelled from the right and left openings of the irregular elliptic hole 230 c to be brought in contact with the side wall 15 a of the case 15 and the lid member 16 . The expansion of the intermediate elastic body 235 is thus suppressed by the above contact, and consequently the sliding resistance thereof at the contact surface is increased.
[123] 123. As described above, right and left side surfaces 230 R and 230 L of the elastic body 230 itself are brought in contact with the side wall 15 a of the case 15 and the lid member 16 respectively, so that the sliding resistance of the elastic body 230 is increased. As a result, the elastic forces of the elastic body 230 and the intermediate elastic body 235 and the sliding resistance of the elastic body 230 are further added with the sliding resistance of the intermediate elastic body 235 . The stroke-load characteristic of the front wheel suspension having the above configuration is shown by a broken line of FIG. 30.
[124] 124. In the stroke-load characteristic of this modification, the gradient of the curve is rapidly raised in a early region with a small stroke, as compared with the characteristic of the third embodiment shown by the solid line. In this way, the front wheel suspension in this modification is allowed to change the stroke-load characteristic with a simple structure in which the intermediate elastic body 235 is inserted and hence to easily obtain a specific characteristic.
[125] 125. Another modification will be described with reference to FIGS. 34 and 35. This modification has the same basic structure as that of the previous modification shown in FIGS. 31 to 33 , except that the shape of an elastic body 240 is slightly different from that of the above-described elastic body 230 . In this modification, parts corresponding to those in the previous modification are indicated by the same characters.
[126] 126. The elastic body 240 having right and left side surfaces 240 R and 240 L parallel to each other is contained in the case 15 between the side wall 15 a and the lid member 16 with gaps therebetween. As shown in FIG. 35, even when the elastic body 240 is pressed, the right and left side surfaces 240 R and 240 L are not brought in contact with the side wall 15 a and the lid member 16 with gaps kept therebetween. Accordingly, upon pressing of the elastic body 240 , the expansion thereof is not restricted, differently from the elastic body 230 in the previous modification.
[127] 127. An intermediate elastic body 245 is inserted in an irregular elliptic hole 240 c of the elastic body 240 , and as shown in FIG. 34, before the elastic body 240 is pressed, the intermediate elastic body 245 is contained in the irregular elliptic hole 240 c . However, as shown in FIG. 35, when the elastic body 240 is pressed, the intermediate elastic body 245 is compressed and expanded in the direction perpendicular to the compression direction, being swelled from the right and left openings of the irregular elliptic hole 240 c , and is brought in contact with the side wall 15 a of the case 15 and the lid member 16 . The expansion of the intermediate elastic body 245 is thus suppressed by the above contact, and thereby the sliding resistance thereof at the contact surface is increased.
[128] 128. Accordingly, when the elastic body 240 is pressed, the elastic force of the elastic body 240 is added with the sliding resistance of the intermediate elastic body 245 , so that there can be obtained a stroke-load characteristic different from that in the previous modification.
[129] 129. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | An inexpensive damping force generating mechanism capable of generating both a compression side damping force and a tensile side damping force has a simple, lightweight structure. The damping force generating mechanism provides an inexpensive axle suspension capable of simplifying the suspension structure, reducing the weight, and effectively utilizing space. The damping force generating mechanism includes an elastic body which generates a damping force when being pressed. An internal pressure generating member is inserted in the elastic body and resists the pressing force. | 5 |
FIELD OF THE INVENTION
[0001] The invention is directed to management of communication networks and in particular to a highlighted object window for a network management graphical user interface.
BACKGROUND OF THE INVENTION
[0002] Due to recent explosive technological development and the ensuing growing size of the communication networks, the network management became a very complex task. Numerous factors contribute to this growing complexity. For example, modern communication networks use heterogeneous equipment provided by different vendors and/or use a multitude of data communication technologies and protocols, a multitude of network management and service provisioning protocols, etc. In addition, the topology of the network is changing at a fast pace. Not only new network elements (NE) are added, removed, moved or replaced with newer versions, but they are also more geographically dispersed. In many cases, the customers wish to divide their network into different regions based on political or business boundaries; quite frequently two or more regions overlap, presenting a challenge given the current engineering limits. All these changes cause significant technological challenges to the nature of network management.
[0003] In a network management system, each managed node is defined by a plurality of “variables”. A management station or the operator can monitor the nodes by examining (reading) the values of these variables, and can control the nodes by remotely changing (writing) the values of these variables. Network information is usually presented in the form of network maps which show graphic symbols (icons) of the NEs on a video display screen of a video display terminal on a workstation. This is called a graphical user interface, or GUI. Each window of the GUI provides the user with the ability to manipulate the information of interest utilizing a mouse, or the like. This user action causes the GUI to process the request by performing the respective action or displaying a map of another hierarchical level.
[0004] It is important that the information displayed by the GUI clearly identifies the network entities for which information is being presented. It is also important for the GUI to provide the user with the ability to select additional information about a particular network entity and to present the information in a clear and well organized display. Finally, displays of network information should be flexible to accommodate differing network configurations and differing network management requirements.
[0005] The networks dynamics causes significant technological challenges to the way in which information is presented to a user. As generally the scale of a communications network is too large and too complex to display all objects of the respective network in a single network map window, the network is divided into hierarchical layers of network object groups, which are shown in separate windows, ranging from upper layer maps of hundreds of network nodes, to lower layer maps of network elements at a certain selected node. This same information can also be represented in a complex tree of objects.
[0006] As the number of network layers increases, it becomes a time consuming job for the user to search through many windows since this involves clicking symbols in a window to open the respective sub-layer map and then clicking on the respective sub-layer map symbols, etc. The complexity of finding the correct object in a tree view representation is equally high. In many cases, this operation could also fail, as it is not easy to follow correctly the hierarchical layers conducting to the desired end result. In practice, a customer evaluates the efficiency of a GUI in terms of the number of mouse clicks it takes an operator to perform a certain function.
[0007] Some network managers (such as Alcatel's 5620 NM) enable customers to highlight objects displayed on a map or a list. The highlighting changes the background color of an object(s), and is used to trace a specific object through a managed system. However, the operator needs to trace an object through different layers of the object hierarchy, so that after performing the highlight function, the operator would still have to navigate through each layer of the hierarchy, one layer at a time.
[0008] Although an attempt to drastically reduce the number of hierarchical layers is impractical because it necessitates overall reconfiguration of the network object containment, it is the usual practice to merge two or more windows by transferring symbols from a lower layer to an upper layer. However, deletion and re-registration of the transferred symbols are necessary. In addition, current network display systems do not allow lower layer maps to be displayed within an upper layer window.
[0009] There is a need to provide a faster, automated way to obtain information on a highlighted chain of objects in a network.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a GUI of a communication network with a highlighted objects window that enables fast access through many layers of hierarchical objects of a network.
[0011] The invention provides a method of displaying highlighted objects information on a graphical user interface (GUI) comprising: a) highlighting a primary object O(n) displayed on a GUI window at a selected hierarchically level (n); b) identifying a highlighted object O(n-1) subtended by the primary object at a hierarchically next lower level (n-1); c) selecting the highlighted object O(n-1) from an object storage means and placing same in a list of highlighted objects; and d) repeating steps b) and c) for all n available hierarchical levels until all highlighted objects corresponding to the primary object are identified and placed in said list.
[0012] According to a further aspect, the invention further provides a highlighted objects window system for a graphical user interface (GUI) of the type provided with highlighting capabilities and adapted to transmit commands and display information with a view to enable management of a communication network. The system comprises means for identifying all highlighted objects in a highlighted hierarchy corresponding to a primary object highlighted on the GUI; and means for selecting only the highlighted objects from an object storage means and placing the objects in a list, the GUI display ing the list in a highlighted objects window where the highlighted objects are arranged in a specified order.
[0013] Still further, the invention provides a method of using a graphical user interface (GUI) of the type provided with highlighting capabilities and adapted to transmit commands and display information with a view to enable management of a communication network, comprising: a) highlighting an original object on a topological map at a selected hierarchically level; b) identifying all highlighted objects corresponding to the original object in all hierarchical levels subtended from the selected hierarchically level; c) selecting all the highlighted objects from an object storage means and placing same in a list in their hierarchical order of identification; and d) displaying the list as a highlighted objects window for obtaining information of interest about the primary object.
[0014] Advantageously, use of the highlighted objects window according to the invention, results in important reduction of the amount of time it takes a user to navigate through the chain of hierarchical objects to obtain the relevant information for the managed objects of interest. In other words, the present solution results in a reduced number of “point and click” operations required for obtaining the information of interest.
[0015] Still another advantage of the invention resides in the ability of the GUI to display the list of objects in the highlight hierarchy, as well as additional information relevant to each object, such as the object type, status, specification, name, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments, as illustrated in the appended drawings, where:
[0017] FIG. 1 shows an example of a network map with a highlighted object;
[0018] FIG. 2 shows the highlighted objects window corresponding to the example of FIG. 1 ;
[0019] FIG. 3 a is a block diagram of the units that enable generation of the highlighted object window according to the invention; and
[0020] FIG. 3 b illustrates how a highlighted objects window list is generated for the example of FIGS. 1 and 2 .
DETAILED DESCRIPTION
[0021] FIG. 1 shows an example of a very simple network management map 10 , illustrating a first node ND 1 , housing a first network device, a second node ND 2 , housing a second network device, and a link 20 between the two network devices. Let's assume that the operator wishes to find the ports on the respective devices that are the ends of link 20 . According to the invention, the operator only has to click and highlight link 20 to obtain a list of all objects involved in this connection.
[0022] FIG. 2 shows a highlighted objects window 30 for the example of FIG. 1 , which displays a list 30 ′ of the objects in the highlight heirarchy. This example has been simplified for clarity, as normally a link will have multiple nodes along the way, each with the respecive shelves, slots, cards, ports, etc. Also, each node could be in a group that could be inside another group, inside another group, etc. In this simplified example, window 30 displays a list 30 ′ showing the group the nodes ND 1 and ND 2 reside in (ON 1 in this example), the first node ND 1 and the first network device ND- 1 P 2 at node ND 1 . The icons of the respective network elements such as group icon 31 , node icon 32 and network device icon 33 are provided in this example in the first column, and the object specification (node identification) in the second column. The object names are also specified in list 30 ′. In this example, the network device ND- 1 P 2 resides in an “Ontario Group”, at an “Ottawa Node” and is called “Ottawa Node P 2 ”.
[0023] The next rows show the objects contained in first network device from the top to bottom of the hierarchy. In this example they are shelf ND 1 -P 2 - 1 identified by icon 34 , card ND 1 -P 2 - 1 - 1 identified by icon 35 and port ND 1 -P 2 - 1 - 1 - 3 identified by icon 36 . For a general case, if we denote the hierarchical level of the map of interest (highest level, original map 10 ) with n and the objects highlighted on this map with O(n), the lower hierarchy objects are denoted with O(n-1), O(n-2) and O(n-3), while the respective levels are denoted with (n-1), (n- 2 ) and respectively (n-3).
[0024] Link 20 is listed next, and is shown using icon 37 . The object specification for this highlighted object indicates the bandwidth of the link “OC48” and the object name gives in this example the direction “Toronto-Ottawa” for the connection over this link.
[0025] The next rows (not shown) list the highlighted objects at the second node ND 2 , namely the objects relevant to the connection over link 20 at a second network device ND- 2 P 2 . These are preferably shown hierarchically from bottom to the top so that the end ports of the link 20 appear in the list above and below the row with the link object. Let's assume that these are port ND 2 -P 2 - 1 - 1 - 1 , card ND 2 -P 2 - 1 - 2 , shelf ND 2 -P 2 - 1 . Toronto end network device ND 2 -P 2 , and node ND 2 end the list of highlighted objects. If ND 2 belongs to a node group, this is also shown in list 30 ′.
[0026] Icons 31 - 37 in the leftmost column quickly identify the object type and status. The colour of the icon indicates its status, therefore locating an alarmed object (e.g. coloured red) in the list is fast.
[0027] Additional columns, such as a status column shown in FIG. 2 , may also be provided depending on the level of information available at the resepective node. Still further, list 30 ′ may include a column with the count of all the objects in the highlighted hierarchy. As all the managed objects of the hierarchically lower layers are shown on the list, the amount of time it takes a user to navigate through the highlight chain and evaluate each iobject is greatly reduced. In addition, GUI 40 enables the operator to select objects in the list 30 ′ for viewing further details if necessary and available.
[0028] List 30 ′ can be sorted by the highlight hierarchy or by any of the displayed columns. Window 30 may also be provided with a refresh button (not shown) for enabling the operator to update list 30 ′ of highlighted objects. Double clicking on a row (line) item in the list provides access to that item.
[0029] FIG. 3 a show a high-level block diagram of the main units involved in generating the highlighted objects window according to the invention. It is to be noted that this figure illustrates only the units at the node relevant to this invention, for simplicity. GUI 40 performs conventional user interface functions enabling an operator to monitor and manage the network as well known. For the example used in this specification, GUI 40 provides an operator with a map (or tree) of interest, here map 10 , that is displayed on the screen of workstation 5 , as well known. In addition, GUI 40 enables the operator to highlight objects displayed in the window. In this example, the operator clicks on link 20 to highlight it.
[0030] The object highlighted on map 10 , here link 20 , and all objects of interest subtended by this primary highlighted object are identified by identifier block 25 based on the GUI 40 object highlight capability. An object list selector 45 accesses the respective objects and object specification information relevant to all the objects identified by unit 25 . Once the information pertinent to the highlighted objects is collected, GUI 40 generates list 30 ′ that is displayed on the screen 5 .
[0031] It is to be mentioned that the location or the way the object specification information is stored at the node is not relevant to the invention; relevant is only availability of this information. In general, all nodes maintain an object library 50 that comprises data pertinent to all network elements at the respective node, available for use by various network management applications. The place where object data is stored is called herein generically “object specification storage” and is denoted with 50 . The information about the ports used by a specified connection is also available at the node, shown generically in FIG. 3 a by connectivity database 55 ; if this information is not readily available, it may be imported from the routing database.
[0032] FIG. 3 b shows how list 30 ′ of highlighted objects is generated for the example of FIGS. 1 and 2 . It is to be noted that this Figure does not illustrate the objects at the device, node and node group level for simplification. To reiterate, the highlighted objects window 30 provides a list of all the objects that are highlighted in a certain window presented by the GUI, from all the layers of the object hierarchy. The objects are arranged in the list in a specified order, as described above.
[0033] First, the operator clicks on link 20 to highlight it, as shown by arrow a. The highlighted objects identifier 25 (see FIG. 3 a ) identifies the objects on map 10 pertinent to the operator's request. Then, the object list selector 45 (see FIG. 3 a ) collects hierarchically the highlighted object data from the object storage 15 that includes generically the pertinent databases with the objects specifications and connectivity data, by first locating the highlighted node group, node and network device information and placing it in list 30 ′ (not shown).
[0034] Next, the highlighted shelf ND 1 -P 2 - 1 is identified in shelf domain 51 corresponding to the first network device, as shown by arrow b. Shelf ND 1 -P 2 - 1 is placed in list 30 ′ together with the relevant information in the respective columns. Then, objects list selector 45 searches domain 52 of cards subtended by this shelf to locate the highlighted card ND 1 -P 2 - 1 - 1 , as shown by arrow c. Card ND 1 -P 2 - 1 - 1 and the relevant information are now placed in the next row of the list 30 ′, and the respective columns of the list are completed with the relevant information. Arrow d shows how the port information is located by searching the domain 53 of ports available on card ND 1 -P 2 - 1 - 1 . The object selector identifies highlighted port ND 1 -P 2 - 1 - 1 - 3 and places it in list 30 ′.
[0035] Link 20 data is searched next, arrow e, in routing domain 54 as it provides the connection between the port-3/card-1/shelf-1/node-P 2 /ND 1 and port- 1 at the Toronto end. This information is also provided to the GUI for insertion in list 30 ′.
[0036] Next, highlighted objects identifier 25 identifies the objects at the second end of link 20 for completing list 30 ′. As described above, the respective object storage unit 15 at the second node maintains the data pertinent to network device ND 2 -P 5 at the Toronto node ND 2 . For this example, these are port ND 2 -P 5 - 1 - 1 - 1 in domain 53 ′ with the ports of card ND 2 -P 5 - 1 - 2 , card ND 2 -P 5 - 1 - 2 from the domain 52 ′ with the cards of shelf ND 2 -P 5 - 1 and shelf ND 2 -P 5 - 1 from the domain 51 ′ with the shelves of the second network device ND 2 . The last items on list 30 ′ are the second network device ND- 2 P 2 and the second node ND 2 . As before, arrows f, g, h and i indicate how the collection of the data proceeds at network device ND 2 . | For displaying information on all highlighted objects in a hierarchical chain of objects, a graphical user interface (GUI), identifies an original highlighted object displayed on a window at a selected hierarchically level. The highlighted object(s) subtended by the original object at the hierarchically next lower level is/are identified and selected from an object storage means, etc, until all highlighted objects corresponding to the original object are identified and selected. The selected objects are placed in a list, and the GIU displays the list in a highlighted objects window where the objects are arranged in a specified order. The list comprises a row for each highlighted object, and a plurality of columns, each column for providing a specified attribute of the object. The GUI may then selects order of the objects in the window by sorting the list by any of the columns. | 7 |
The application is based upon U.S. Provisional Patent Application Ser. No. 60/077,192 filed on Mar. 2, 1998.
This invention relates generally to a device for securing one or more articles relative to a vehicle for transporting the articles, and in particular to a portable base to which such articles can be lashed by means of tensioning tie-downs having opposing ends hooked to a webbing or grid surface of the base.
BACKGROUND
Stretchable tie-down cords, often referred to as bungee cords, have been in use for a considerable period to lash objects to roof and trunk-lid racks of automobiles. In addition, various kinds of techniques have been used to lash bicycles, motorcycles and a variety of other items to the beds of pick-up trucks by utilizing fixed anchoring members which are built into the truck. But when it comes to securing an unstable article on a flat vehicular surface which has no built-in anchoring means, such for example as the back bed of a station wagon, mini-van, panel or pick-up truck, hatch-back or sport utility vehicle, the typical approach is to brace the article as well as possible against an inside comer and maintain it there with a heavier and more stable item or items.
SUMMARY OF THE INTENTION
An unstable article is secured to a portable base having a webbing or grid enabling use of tensioning tie-downs which are hooked into the webbing and stretched over the article to temporarily lash the article to the base while being transported. The webbing is affixed to a frame of interconnected rods which are interwoven with the webbing. The frame also includes channel members which interconnect the rods to one another. The webbing permits securing the article nearly universally anywhere on the base, i.e., its location is not limited by the position of bars or rails as in the case of permanently fixed racks. The base or frame is capable of being collapsed or disassembled for purposes of making it more compact for shipping or storage. In its broadest sense, the frame and webbing comprise a temporary enlarged base for the article to be transported, enabling it to be placed loosely on a flat horizontal bed or surface while preventing the article from toppling, sliding or otherwise shifting about uncontrollably as the vehicle makes turns, stops or starts.
A principal object of the invention is to provide an enlarged temporary base for an article to be transported while the base and article are resting freely on a flat surface.
More specifically, it is an object to provide such a base of nominal vertical height, the base consisting of a plurality of rods and a webbing with interstices and cross strands through which the rods may be interwoven.
A further object is to provide such a base of a construction enabling its easy collapsing and converting into a compact roll for purposes of storage and shipment.
Other objects and advantages will become apparent from the following description, in which reference is made to the accompanying drawings.
IN THE DRAWINGS:
FIG. 1 is a simplified isometric view of the portable base with an article such as a computer monitor lashed thereto by means of tie-down cords.
FIG. 2 is an enlarged detailed plan view of one corner of the base of FIG. 1, that corner being the one illustrated within the dot-dash oval 2 of FIG. 1
FIG. 3 is a fragmentary elevational view taken substantially along lines 3--3 of FIG. 2.
FIG. 4 is a fragmentary elevational view taken substantially along lines 4--4 of FIG. 2.
FIG. 5 is a simplified isometric view of the base of FIG. 1 after it has been collapsed and rolled up for storage or shipping.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a simplified version of a base member 10 which serves to support an unstable article, which in this illustration is a computer monitor 12. The terminology "unstable article" as used herein means any kind of article which can topple, slide or shift during transport. Any of several different kinds of articles can carried by the base member, the one shown having instability due to its typical swivelability both about a vertical and a horizontal axis as well as its relatively small base in relation to its high-center-of-gravity cathode ray tube housing. The monitor or other article is lashed to the base member 10 by a plurality of tie-downs or bungee cords 14, each of which has a pair of hooks 16 firmly connected to the opposite ends thereof. Such cords are well known for purposes of lashing or securing articles to a support, ordinarily to stabilize the articles against unwanted movement, e.g., shifting, toppling or sliding.
The preferred base member 10 is shown to be rectangular in plan view, because of its ease of manufacture in that configuration. Other shapes are also feasible, but for ease of explanation, only a rectangular version will be discussed. A webbing 18 having grid openings 20 throughout its surface covers the entire rectangular shape shown. Interwoven with or threaded through the webbing 18 at two opposite sides thereof are two outer rods 22. Parallel to rods 22 are a plurality of intermediate rods 24, which may differ from rods 22 only at their very ends, as will be noted later. Rods 24 are preferably also interwoven with the webbing 18, by threading them alternately through adjacent grid openings 20 as shown at the top and bottom of FIG. 2. The ends of rods 22 and 24 have small diameter holes 26 drilled therethrough. The holes 26 enable cable ties or other securing means 28 to hold the webbing 18 taut between the ends of the rods 22 and 24.
While a variety of different types of webbing or netting may be used, I prefer to use the type commonly found in the snow fence field, because of its strength, light weight and toughness. An example of such fence can be found in U.S. Pat. No. 5,661,944 issued on Sep. 2, 1997 and assigned to Tensar Corporation of Atlanta, Ga. The particular material discussed in that patent is said to consist of molecularly-oriented elongated cross strands 29 with unoriented strand junctions surrounding the grid openings 18. It serves the purposes of this invention quite well, but as mentioned earlier, is one of several different kinds of taut webbing which can be used. This thermoplastic material can be easily rolled, and when unrolled, can be kept in a flat, taut condition if secured to a flat structure. The cross strands and the opening size of this type of snow fence serves very well to enable universal securement of an article in any location on the base member 10 by hooking the elongated strands or anchoring with the hooks at the ends of the cords 14.
The strands 29 anchor the hooks 16 securely to the webbing 18 as shown in FIG. 3. That Figure also illustrates how the rods 22 and 24 interleave with the webbing between adjacent grid openings 20, with one strand extending over a rod and the next adjacent strand extending beneath a rod. As can be seen in FIG. 3, the majority of the webbing 18 is at a height "x" above a floor 30, which dimension is approximately one half the diameter of a rod 22 or 24. The vertical dimension of the base 10 may be on the order of 1/2 to 3/4 of an inch. The rods may be of a shape other than cylindrical, but the shape shown is preferred because the rods then need no particular orientation relative to the webbing in order to rest evenly on the floor 30 or on carpeting on the floor. A resilient friction pad (not shown) may be used to substitute for carpeting in the case where the base member lays directly on a metal floor such as the bed of a pick-up truck. While the webbing below the rods 22 and 24 tends to have a frictional relationship with a floor, a friction pad can assist in inhibiting any tendency of the base and the article it is carrying to slide relative to the floor, particularly where their entire weight is insubstantial. The rods 22 and 24 have sufficient lateral flexibility to press the webbing surrounding the rods into contact with the floor. The rods may be metal, wooden dowel, fiberglass or some other material, their function being to provide enough rigidity to the frame and base to maintain the webbing taut for anchoring purposes.
A pair of channels 32 which may be U-shaped in cross section cooperate with the rods 22 and 24 to form the stable framework of the base member 10. As can best be seen at the lower right hand of FIG. 2, an end of a channel 32 locks with the end of the rod 22 by having the channel's bottom end enter a slot 34 formed between the end of the rod 22 and an L-shaped stop member 36. The stop member 36 is secured to the rods 22 by welding or other fastening means. All four comers may be and preferably are similarly constructed. As can be seen in FIG. 4, the intermediate rods 24 can be provided with end caps 38 of a diameter closely approximating the dimension between the legs of the U-shaped cross section of the channels 32. The rods 24 are thus restrained against vertical movement within the channels when supporting an article.
When the base member 10 rests on the floor 30 of a vehicle and has an article secured thereto as shown in FIG. 1, the base member essentially enlarges the "footprint" of the article by temporarily being integral therewith. A typical computer monitor 12 would be very unstable if one were to permit it to rest without being restrained in some manner in the back of a station wagon, e.g., when starting, stopping or turning a comer. By fastening the monitor 12 to a larger base, its being integral with the larger base permits it to rest freely on the floor without further securement. If the floor is carpeted, the rods 22 and 24 will tend to sag slightly from the weight of the monitor and will grip the carpet. The framework of the base member 10, while being capable of limited flexing if unsupported, becomes very rigid within its own plane once the weight of an article is added thereto and the article is lashed securely to the webbing 18 by the cords 14.
When not in use, the base member 10 can be disassembled or collapsed and the full structure rolled up fairly tightly as shown in simplified fashion in FIG. 5. The rolled condition enables easy storage of the unit, as well enabling easy shipping or keeping boxed in inventory at a retail operation. Breaking down the unit from assembly for storage can best be seen from viewing FIG. 2 at the lower right hand comer. Although the webbing 18 is taut when in the position of FIG. 1, a limited measure of web stretching within its plane is possible. For example, rod 22 can be pulled downwardly as viewed in FIG. 2 until the end of the channel 32 captured within slot 34 is no longer entrapped. When one comer of channel 32 and rod 22 is disconnected from slot 34, the same channel can be slipped from the corresponding slot at its opposite end and the channel can be moved laterally away from the end caps 38 to disengage the channel from the intermediate rods 24. Once the first channel has been removed from the framework, the base member becomes very flimsy and the second channel can be removed with ease. The two channels 32 can then be laid on the webbing parallel to and alongside one of the rods 22 and the webbing and rods 22 and 24 rolled to the shape of FIG. 5. Reassembly is accomplished in the reverse order, with the final corner requiring the webbing to be stretched to enable the end of channel 32 to enter slot 34 and lock everything together when tension in the webbing is relaxed.
Various forms of interconnection at the comers of the base member 10 are feasible, but I prefer to use a fastening technique that permits assembly and disassembly without the use of tools. Additionally, while I prefer to have a pair of single piece channels, they need not be channel-shaped, nor need they be in one elongated piece. The size of the base member 10 in plan view can be of any dimension to fit the floor configuration of the vehicle with which it will ordinarily be used. It is considered within the scope of my invention to sell the elements of the base member in kit form, allowing the webbing to be cut to a specific size with scissors, sawing the lengths of the rods and channels to the new size of webbing, drilling new holes 26 if necessary, and tailoring the size of the base member to suit a person's own needs. Since the rods are easily interwoven with the webbing, accomplishing this is believed sufficiently easy to do for an average home handyman.
Various other changes may be made without departing from the spirit and scope of the claims. | An unstable article to be transported is mounted on a portable base member. The base member consists of a webbing, a plurality of parallel rods interwoven with the webbing and a pair of channel members extending at right angles to the rods and interconnecting with the rods to form a frame for supporting the webbing in a tautened condition. The article utilizes the base member as a temporary, portable expanded base for the article to support the article and prevent its toppling, sliding or shifting during transport. The base member may be collapsed and rolled into a compact unit for shipping or storage. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a system for controlling line pressure in an automatic transmission where the pressure is controlled dependent on vehicle speed and throttle opening degree by operating a solenoid operated valve provided in the system.
In a conventional hydraulic circuit for an automatic transmission, the line pressure is controlled by a pressure modifier valve actuated by governor pressure which changes with vehicle speed. As shown in FIG. 5, the line pressure is stepwisely changed from a high level value to a low level value in accordance with the vehicle speed. Namely, in a low vehicle speed range, where engine torque is large, the line pressure is at a high level and in a high vehicle speed range, where the torque becomes smaller, the line pressure is reduced.
Japanese Utility Model Laid Open No. 56-127141 discloses an automatic transmission comprising a hydraulic circuit having three shift valves and an electronic control circuit having a solenoid operated valve to which a signal dependent on vehicle speed and on engine load is applied. The solenoid operated valve is arranged to produce control pressures of three levels. The shift valves are operated by different control pressures respectively, so that the transmission ratio may be changed.
However, in the line pressure control shown in FIG. 5, since the line pressure can only be kept at either of the two levels, there are two regions designated by A and B where line pressures are too high relative to the torque. In such regions, pump loss in an oil pump and shock which occurs at changing of the transmission ratio increase.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a system for controlling line pressure in an automatic transmission device, wherein the proportion of the line pressure to engine torque is kept relatively constant at any vehicle speed so that pump loss and shock which occurs at the changing of the transmission ratio are reduced.
According to the present invention, there is provided a system for controlling line pressure in a hydraulically operated automatic transmission for a motor vehicle comprising an engine load detector for producing a load signal dependent on load on an engine of the vehicle, a vehicle speed detector for producing a vehicle speed signal dependent on speed of the vehicle, a line pressure calculator responsive to the load signal and vehicle speed signal for producing a line pressure signal representing line pressure, and control signal generating means responsive to the line pressure signal for producing a control signal.
A hydraulic circuit of the automatic transmission has an electromagnetic valve operated by the control signal, for controlling pressure of a control oil in a hydraulic circuit of the automatic transmission, and a pressure regulator valve is provided in the hydraulic circuit and operated by the control oil to control line pressure, and the line pressure calculator produces the line pressure signal representing the necessary line pressure which increases with the load signal and decreases with the vehicle speed signal and has a constant value when the load signal and the vehicle speed signal exceed respective predetermined values so as to approximate the line pressure to torque of the engine.
In an aspect of the invention, the engine load detector is a throttle opening degree calculator, the control signal comprises pulses, and the electromagnetic valve is a solenoid operated valve. The system has further a pressure modifier valve operated by the control signal, for generating modifier pressure for operating the pressure regulator valve.
The present invention will be more apparent from the following description made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1a and 1b show a four-wheel drive power transmission system and a block diagram of a control unit provided in the system of the present invention;
FIG. 2 is a schematic diagram of a hydraulic circuit for controlling line pressure;
FIG. 3 is a graph showing characteristics of engine torque and line pressure at wide-open throttle;
FIG. 4 is a graph showing a relationship between line pressure and throttle opening degree; and
FIG. 5 is a graph showing characteristics of engine torque and line pressure in a conventional system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, an internal combustion engine E is mounted on a front portion of a vehicle. A crankshaft 1 of the engine E is operatively connected with a torque converter 3 having a lockup clutch 2 of an automatic transmission A. The automatic transmission A comprises the torque converter 3, and an automatic transmission device 5 operatively connected with the torque converter 3 through an input shaft 4.
The output of the automatic transmission device 5 is transmitted to an output shaft 6 on which a drive gear 7 is securely mounted, and the drive gear 7 engages with a driven gear 7'. The driven gear 7' is securely mounted on a front drive shaft 8, which is integral with an drive pinion 8a engaged with a crown gear 9 of a final reduction device for the front wheels of the vehicle. The output shaft 6 is connected to a rear drive shaft 11 through a transfer clutch 10 which is in a form of a fluid operated multiple-disc friction clutch. The rear drive shaft 11 is further operatively connected to a final reduction device 13 for rear wheels of the vehicle through a propeller shaft 12.
The automatic transmission device 5 is supplied with pressurized oil from a hydraulic control device 14 which is provided under the front drive shaft 8. The hydraulic control device 14 is controlled by a control unit 15 (FIG. 1b). The control system is further provided with a throttle position sensor 16, vehicle speed sensor 17 and line pressure sensor 18 for controlling a solenoid operated valve provided in the hydraulic control device 14.
Referring to FIG. 2 showing a hydraulic circuit for controlling line pressure, the circuit has a pressure regulator valve 21, a solenoid operated valve 19, a pressure modifier valve 22, and a pilot valve 23. Oil from an oil pump 20 is supplied to pressure regulator valve 21. The pressure regulator valve 21 is supplied with modifier pressure Pa from the pressure modifier valve 22 at the upper end. An upper chamber of the pressure modifier valve 22 is applied with duty pressure Pb which is determined in accordance with the duty cycle of the solenoid operated valve 19. The solenoid operated valve 19 which is operated by pulses from the control unit 15 opens to drain the oil from a drain port 30 when energized. The pressure regulator valve 21 and the pressure modifier valve 22 are communicated with the pilot valve 23. When the duty cycle of the solenoid operated valve 19 increases, amount of drain oil increase, thereby reducing the duty pressure Pb. When duty pressure Pb reduces, a spool 22a rises to reduce the modifier pressure Pa. Accordingly, line pressure P regulated by the regulator valve 21 becomes lower. Thus, the line pressure P is controlled to an optimum value dependent on the driving conditions by controlling the duty cycle of the solenoid operated valve 19.
As shown in FIG. 1b, the control unit 15 for controlling the solenoid operated valve 19 comprises a throttle opening degree calculator 25 and a vehicle speed calculator 26 to which output signals of the throttle position sensor 16 and the vehicle speed sensor 17 are applied, respectively. A throttle opening degree signal θ calculated by the calculator 25, vehicle speed signal V calculated by the calculator 26 and present line pressure signal Po detected by the line pressure sensor 18 are applied to a line pressure calculator 27 which produces a corrected line pressure signal Pc. The line pressure signal Pc represents necessary line pressure and is fed to a duty cycle calculator 28 where duty cycle D corresponding to the necessary line pressure is calculated. Therefore, the solenoid operated valve 19 is operated at the duty cycle D.
The calculation for obtaining the line pressure P is described hereinafter with reference to FIGS. 3 and 4.
In the present invention the line pressure P is controlled to increase with the increase of the throttle opening degree θ and to decrease with the increase of the vehicle speed V in a low vehicle speed range. FIG. 3 shows a relationship between the line pressure P and vehicle speed V at wide-open throttle (θ=θw), as an example. When the vehicle speed V is lower than a predetermined speed V 1 , for example a vehicle speed at which the lockup clutch of the torque converter is released, the line pressure decreases linearly in accordance with the following equation.
P=f(P.sub.O -CV) (C is a constant)
When the vehicle speed V reaches the predetermined speed V 1 so that the lockup clutch is locked, the line pressure P is kept at a value P H (P=P H ). Accordingly, the characteristic of the line pressure P at wide-open throttle approximates that of engine torque F so that the proportion of the line pressure P to the torque F is substantially constant at any vehicle speed.
FIG. 4 shows relationships between the line pressure P and the throttle opening degree θ when the vehicle speed as a parameter is lower than vehicle speed V 1 (V≦V 1 ). When the throttle opening degree θ is smaller than a predetermined degree θ 1 (θ≦θ 1 ), the line pressure P is maintained at a predetermined value P 1 as shown by line 1 1 .
When the throttle opening degree θ is between the predetermined degree θ 1 and another predetermined degree θ 2 which is larger than the predetermined degree θ 1 (θ 1 <θ≦θ 2 ), the line pressure P is calculated as follows.
P=f[(kaθ+kb)×(kc-kdV)] (ka to kd are constants)
Accordingly, the line pressure P increases with increase of the throttle opening degree θ, as shown by lines 1 2 .
When the throttle opening degree θ exceeds the predetermined degree θ 2 (θ>θ 2 ), the line pressure P is calculated as follows.
P=f(ke-kgV) (ke and kg are constants)
Thus, the line pressure P is kept constant as shown by lines 1 3 .
When the vehicle speed V exceeds the predetermined speed V 1 (V>V 1 ) while the throttle opening degree θ is below θ 1 , the line pressure P is constant at the pressure P 1 . When the throttle opening degree θ is between θ 1 and θ 2 , the line pressure P is calculated in accordance with the following equation.
P=f[(kaθ+kb)×(kc-kdV.sub.1)]
Namely, the line pressure P is a function of the throttle opening degree θ. When the throttle opening degree θ becomes larger than the predetermined value θ 2 , the line pressure is kept constant at the value P H which is obtained by the following equation.
P.sub.H =f[(kaθ.sub.2 +kb)×(kc-kdV.sub.1)]
From the foregoing, it will be understood that the present invention provides a line pressure control system where the proportion of line pressure to torque is maintained substantially constant at any vehicle speed. Accordingly, pump loss of an oil pump provided for the automatic transmission device is decreased.
While the presently preferred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | A system for controlling line pressure has a line pressure calculator for producing a line pressure signal in response to load on an engine and vehicle speed, a control signal generator responsive to the line pressure signal for producing a control signal, and an electromagnetic valve operated by the control signal, for controlling pressure of control oil in a hydraulic circuit of an automatic transmission. A pressure regulator valve provided in the hydraulic circuit is operated by the control oil to control line pressure. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a zigzag wavelength division multiplexer, and in particular to a zigzag wavelength division multiplexer reducing the wavelength shift in the center of a frequency band resulting from temperature changes.
2. Description of the Related Art
FIG. 1A is a schematic perspective view showing a conventional zigzag wavelength division multiplexer. The conventional zigzag wavelength division multiplexer (U.S. Pat. No. 5,859,717) includes a housing 1 . A support 2 , a first collimator 3 , a second collimator 4 , a third collimator 5 , a fourth collimator 6 , a fifth collimator 7 and a sixth collimator 8 are disposed in the housing 1 . A first wave filter 9 , a second wave filter 10 , a third wave filter 11 and a fourth wave filter 12 are disposed in the support 2 . The first collimator 3 outputs multi-channel collimated light to the first wave filter 9 at an incident angle. Generally speaking, the incident angle is between 5° and 9°. Preferably, the incident angle is 7°. Specifically, the wavelength of light passing through the wave filter is changed whenever the incident angle is changed by 0.15°. Furthermore, the higher the incident angle, the higher the polarization dependent loss (PDL).
In the conventional zigzag wavelength division multiplexer (U.S. Pat. No. 5,859,717), spacers 13 are used to fix the collimators, as shown in FIG. 1 B. The spacers 13 can only prevent length change of the collimator resulting from thermal expansion and contraction, but not tilt angle between the collimator and the wave filter. Thus, the adhesive 14 causes tilt angle between the collimator and the wave filter resulting from thermal expansion and contraction, and the tilt angle causes wavelength shift in a frequency band and subsequent light loss.
SUMMARY OF THE INVENTION
An object of the invention is to provide a zigzag wavelength division multiplexer. The zigzag wavelength division multiplexer comprises an intermediate block, an input end and a plurality of output ends. The input end is disposed on one side of the intermediate block and has a first sleeve and an optical collimator. The first sleeve has a first fixing portion having a hole. The axis of the first sleeve is tilted to the plane of the opening of the first sleeve at a first angle. The optical collimator is disposed in the first sleeve and fixed to the first fixing portion. The output ends are disposed on two sides of the intermediate block. Each of the output ends has a second sleeve, a GRIN lens, a first pad, a glass ferrule, a second pad and a wave filter. The second sleeve has a first portion, a second portion and a second fixing portion having a hole. The axis of the first portion is coaxial to that of the second portion. The axis of the second portion is tilted to the plane of the opening of the second portion at a second angle. The GRIN lens is disposed in the first portion and fixed to the second fixing portion. The first pad is disposed on one end of the GRIN lens. The glass ferrule is disposed on the first pad. The second pad is disposed on the opening of the second portion of the second sleeve and the side of the intermediate block. The wave filter is disposed in the second portion and on the second pad. After multi-channel light enters the intermediate block via the input end, the output ends output corresponding channel light, respectively.
The invention has the following advantages. The invention uses sleeves to fix the optical collimators and the wave filters, thus preventing a tilt angle between the optical collimator and the wave filter. In addition, the invention reduces the wavelength shift in the center of a frequency band resulting from temperature changes. Furthermore, the invention uses the sleeves to fix the optical collimators and the wave filters, thus reducing light loss.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1A is a schematic perspective view showing a conventional zigzag wavelength division multiplexer;
FIG. 1B is a schematic view showing the conventional zigzag wavelength division multiplexer using spacers to fix the collimator;
FIG. 2 is a schematic top view showing the zigzag wavelength division multiplexer of the invention;
FIG. 3A is a schematic perspective view showing an optical collimator;
FIG. 3B is a schematic perspective view showing the input end of the zigzag wavelength division multiplexer of the invention;
FIG. 4A is a schematic perspective view showing an output end of the zigzag wavelength division multiplexer of the invention;
FIG. 4B is a schematic perspective view showing another output end of the zigzag wavelength division multiplexer of the invention;
FIG. 4C is a schematic enlarged view showing the second sleeve according to FIG. 4B;
FIG. 5 shows the pad of the zigzag wavelength division multiplexer of the invention; and
FIG. 6 is a schematic view showing the configurations of the pad.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2, the zigzag wavelength division multiplexer includes an intermediate block 20 , an input end 30 and a plurality of output ends 40 a, 40 b, 40 c and 40 d. The input end 30 and the plurality of output ends 40 a, 40 b, 40 c and 40 d are disposed on two sides 20 a and 20 b of the intermediate block 20 . After multi-channel light enters the intermediate block 20 via the input end 30 , the first output end 40 a outputs a first channel beam λ 1 , the second output end 40 b outputs a second channel beam λ 2 , the third output end 40 c outputs a third channel beam λ 3 , and the fourth output end 40 d outputs a residual channel beam λ 4 .
Referring to FIG. 3A, the optical collimator 50 includes at least a GRIN lens 51 and a glass ferrule 52 . An optical fiber 53 is disposed in the glass ferrule 52 . The optical collimator 50 further includes a glass tube 54 to fix the GRIN lens 51 and the glass ferrule 52 .
Referring to FIG. 3B, the input end 30 has the optical collimator 50 and a first sleeve 60 . A fixing portion 61 having a hole 62 is formed on the inner wall of the first sleeve 60 . The optical collimator 50 is disposed in the first sleeve 60 and fixed to the fixing portion 61 by hot solidified resin. The axis of the first sleeve 60 is tilted to the plane of the opening of the first sleeve 60 at a predetermined angle θ. Preferably, the angle θ is between 75° and 90°.
Referring to FIG. 4A, the output end 40 has a GRIN lens 41 , a glass ferrule 42 , a wave filter 43 , a first pad 44 , a second pad 45 and a second sleeve 80 . The second sleeve 80 has a first portion 81 , a second portion 82 and a fixing portion 83 . The fixing portion 83 has a hole 84 connected between the first portion 81 and the second portion 82 . In the second sleeve 80 , the axis of the first portion 81 is coaxial to that of the second portion 82 . The axis of the second portion 82 is tilted to the plane of the opening of the second portion 82 at the predetermined angle θ. Preferably, the angle θ is between 75° and 90°. The wave filter 43 is disposed in the second portion 82 and fixed to the second pad 45 by hot solidified resin 70 , and the opening of the second portion 82 is fixed to the second pad 45 by hot solidified resin 70 . The GRIN lens 41 is disposed in the first portion 81 and fixed to the fixing portion 83 by hot solidified resin 70 . The first pad 44 is fixed to an end 41 a of the GRIN lens 41 by hot solidified resin 70 . The glass ferrule 42 is fixed to the first pad 44 by hot solidified resin 70 .
As described above, an optical collimator 46 having the first pad 44 is disposed in the first portion 81 and fixed to the fixing portion 83 of the second sleeve 80 by hot solidified resin 70 . The second sleeve 80 and the wave filter 43 are fixed to the second pad 45 by hot solidified resin 70 . Thus, the output end of the present zigzag wavelength division multiplexer is constructed. As shown in FIG. 4A, the output end of the present zigzag wavelength division multiplexer is disposed on one side of the intermediate block 20 by hot solidified resin 70 .
Referring to FIG. 4 B and FIG. 4C, another output end of the present zigzag wavelength division multiplexer includes a GRIN lens 41 , a glass ferrule 42 , a wave filter 43 , a first pad 44 and a second sleeve 80 . The second sleeve 80 has a first portion 81 , a second portion 82 and a fixing portion 83 . The fixing portion 83 has a hole 84 connected between the first portion 81 and the second portion 82 . In the second sleeve 80 , the axis L 1 of the first portion 81 is tilted to the axis L 2 of the second portion 82 at a predetermined angle θ′. The axis L 2 of the second portion 82 is perpendicular to the plane of the opening of the second portion 82 . As shown in FIG. 4B, the wave filter 43 is disposed in the second portion 82 and fixed to the fixing portion 83 by hot solidified resin 70 . Because of the predetermined angle θ′ between the axis L 1 of the first portion 81 and the axis L 2 of the second portion 82 , the wave filter 43 is substantially parallel to the side of the intermediate block 20 . The GRIN lens 41 is disposed in the first portion 81 and fixed to the fixing portion 83 by hot solidified resin 70 . The first pad 44 is fixed to an end 41 a of the GRIN lens 41 by hot solidified resin 70 . The glass ferrule 42 is fixed to the first pad 44 by hot solidified resin 70 . Thus, the glass ferrule 42 , the first pad 44 and the GRIN lens 41 construct the optical collimator 46 having the pad.
As described above, an optical collimator 46 having the first pad 44 is disposed in the first portion 81 and fixed to the fixing portion 83 of the second sleeve 80 by hot solidified resin 70 . In addition, the optical collimator 46 having the first pad 44 , the second sleeve 80 and the wave filter 43 construct the other output end of the present zigzag wavelength division multiplexer. As shown in FIG. 4B, the other output end of the present zigzag wavelength division multiplexer is fixed to the intermediate block 20 by hot solidified resin 70 .
FIG. 5 shows the pad of the zigzag wavelength division multiplexer of the invention. As shown in FIG. 4A, FIG. 4 B and FIG. 5, there is no effect on light penetration when the thickness t of the pad 45 is changed. On the other hand, light penetration is affected when the thickness t of the pad 44 is changed.
FIG. 6 is a schematic view showing the configurations of the pad. The pad is hollow and has circular, rectangular and polygonal configurations. Additionally, the pad is made of metal, glass or other materials not deformed at temperatures over 200° C.
The intermediate block is made of a transparent material such as glass or quartz. Additionally, the intermediate block can be a hollow metal block.
In addition, the length of the first sleeve of the input end is substantially equal to that of the optical collimator. Furthermore, the depth of the first portion of the second sleeve of the output end is smaller than or equal to the length of the GRIN lens.
While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | A zigzag wavelength division multiplexer. The zigzag wavelength division multiplexer reduces the wavelength shift in the center of a frequency band caused by temperature changes. The zigzag wavelength division multiplexer includes an intermediate block, an input end and a plurality of output ends. The input end has a first sleeve and an optical collimator disposed in the first sleeve. Each of the output ends has a second sleeve, a wave filter and an optical collimator. The optical collimator and the wave filter are disposed in the second sleeve. The zigzag wavelength division multiplexer reduces use of the GRIN lens and glass ferrule, and thereby manufacturing costs. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for increasing the production of a desired protein in bacteria, fungi, plant and animal cells. More specifically this is achieved by introduction of slowly translated codons in the encoding DNA gene sequence. Moreover, there is provided a method of decreasing the half-life of a mRNA transcript from a gene encoding a peptide.
BACKGROUND OF THE INVENTION
[0002] Increasing the levels of transcription of a gene is well known in the art to lead to higher levels of the protein encoded by the overexpressed gene. It is also well known in the art that overproduction of proteins by means of transcription overexpression may lead to undesirable effects on cellular metabolism (WO 98/07846). Furthermore, it has also been described that protein overproduction may lead to deleterious effects in the translational machinery of the host cell (Hengjiang et al., 1995, J. Bacteriol. 177.1497-1504) and/or induction of proteolytic activities mediated by stress responses (Ramirez D. M., and W. E. Bentley, 1995, Biotechnol. Bioeng. 47:596-608) which could be the consequence of lower production titers.
[0003] Therefore, devising methods for protein overproduction alternative to the use of constitutive strong promoters could be advantageous.
[0004] Transcript degradation is utilized by microorganisms as a means to control cellular protein content. On the other hand, microorganisms have developed mechanisms by which the stability of a given transcript is enhanced. To achieve this, transcripts are provided with nucleotide sequences capable of forming secondary structures which impose an impediment for mRNA degrading enzymes to exert their action.
[0005] Smolke et al. (2001, Metabolic Engineering. 3: 313-321) describe the use of artificially generated sequences capable of stem-loop structure formation as mRNA stability elements to increase the steady-state level of transcripts encoded by two plasmid-borne crt genes in order to increase phytoene production in Escherichia coli . For this method to be useful, the above-mentioned mRNA stability elements must be precisely placed no more than one nucleotide away from a promoter transcriptional start site (Carrier and Keasling 1999, Biotechnol. Prob. 1, 5: 58-64). Alternatively, if cleavage is desired at a site within the native mRNA molecules, the mRNA stabilizing element is required to be co-introduced with an RNase E cleavage site so that RNase E—specific cleavage results in a new mRNA molecule of similar structure, i.e. placement of the RNA stability element one (1) nucleotide from the 5′ end. Either example requires laborious experimental work, limiting the usefulness of the method.
[0006] Thus the development of stabilizing mRNA independent of promoters at the transcriptional start sites or independent of RNase E cleavage could offer a better alternative to engineer microorganisms for the manufacture of proteins at the industrial level.
[0007] Most mRNA in E. coli decay with functional half-lives close to two minutes at 37° C., but a few mRNA species differ substantially in their half-life resulting in a span among mRNA half-lives of close to 100-fold (Blundell et al, 1972, Pedersen et al, 1978, Gerdes et al, 1990). The extraordinary stability of the latter mRNA depends on sequestering of the mRNAs 5′ end into a structure (Franch et al, 1997). Characterization of mutants with altered mRNA half-lives has led to models for the mRNA degradation where endonuclease RNaseE, the exonucleases RNase II and RNase R, polynucleotide phosphorylase (Babitzke and Kushner 1981, Donovan and Kushner, 1986, Cheng and Deutcher, 2005) and polyA-polymerase I that poly-adenylates the 3′ end of the mRNA combine to form a complex, a “degradosome” responsible for the decay of the mRNA (Yarchuk et al 1992, Dreyfus and Regnier, 2002; Kushner, 2002; Deana and Belasco, 2005). It is likely that separate pathways for the degradation of specific mRNAs exist (Deana and Belasco, 2005; Carabetta et al 2009).
[0008] Attempts have been made to characterize the initial event that specifies the inactivation of an mRNA that is followed by a rapid chemical degradation of the mRNA. Petersen (1987) constructed eight variants of the lacZ mRNA with small sequences inserted in the early coding part of the mRNA and determined their functional half-lives and translation initiation frequencies. These changes decreased the mRNA half-life but the half-life did not appear to be influenced by the translation initiation frequency or by hairpin mRNA structures early in the coding region. By contrast, by introducing wild type and mutated ribosome binding sites from other genes into the lacZ gene, Yarchuk et al, (1992) got results indicating that cleavage by RNaseE was the rate limiting step for mRNA degradation and that the rate of such cleavage was influenced by the translation initiation frequency. When the lacZ ribosome-binding site was substituted with sites expected to bind ribosomes with a higher affinity, the levels of protein expression from these constructs were increased. This was largely due to an increased mRNA half-life and only marginally due to an increased rate of translation initiation (Vind et al, 1993). This indicated that small increases in the ribosome density on an mRNA increased its half-life substantially. In general, the translation efficiency of the mRNA has a large influence on its stability but the event that initiates the decay and determines the functional half-life of the mRNA was therefore elusive (reviewed in Deana and Belasco, 2005).
[0009] Recently, the hydrolysis of the 5′ tri-phosphate to a 5′ mono-phosphate group at the end of the mRNA, catalysed by the RppH enzyme, was suggested to be an initial and rate-limiting step in the mRNA degradation (Celesnik et al 2007, Deana et al 2008). Secondary mRNA structures in the 5′ untranslated region were shown to protect the 5′ tri-phosphate group and to stabilize the mRNA. However, the mRNAs characterized by Petersen (1987) were identical with respect to the initial 52 nucleotides of the lacZ mRNA which includes the first fifteen nucleotides of the coding region and thus did not vary in the 5′-untranslated region. Nevertheless, minor sequence changes shortly after codon 5 resulted in an up to four-fold decrease of the mRNA half-life.
[0010] Recently the translation process was modelled with focus on kinetic data where translation of lacZ mRNA with inserts of slowly translated codons indicated the formation of ribosome queues. This allowed estimation of translation initiation rate on lacZ mRNA in living E. coli rather precisely to 1 initiation per 2.3 sec under the conditions used, growth in glycerol minimal medium. This analysis also indicated that stochastic collisions between ribosomes are normal, frequent and probably harmless events (Mitarai et al 2008). Because it takes approximately one second to translate the 11 codons that is covered by a ribosome, the distance between the ribosomes translating the lacZ mRNA is on average just above one ribosome diameter, subject to varying local translation rates and to stochastic fluctuations. The translation rate among individual codons varies approximately ten-fold (Sørensen and Pedersen 1991), enough to give large local variations in the spacing of the ribosomes even with an identical translation initiation frequency.
[0011] Consequently, it is an object of the present invention to provide a method to increase the production of a desired protein in a microorganism without strengthening native promoter signals controlling transcription of said structural gene sequences.
SUMMARY OF THE INVENTION
[0012] The inventors of the present invention have used a refined modelling to be able to analyse the ribosome distribution on different mRNA sequences in quantitative terms. Using this refined model on lacZ variant mRNAs with either altered ribosome-binding sites, or with changed codons in the early coding part of the mRNA, the inventors surprisingly found a clear correlation between the mRNAs functional half-life and the fraction of time an initial part of the mRNA is uncovered by ribosomes. These findings have been verified with in vivo.
[0013] Based on these findings the present inventors have contemplated a method to increase the production of a desired protein in a microorganism by introduction of one or more slowly translated codons in the encoding DNA gene sequence capable of slowing down the translation speed of the ribosomes moving along the mRNA, whereby the ribosomes protect the mRNA from being enzymatically degraded. This increases the stability of the mRNA transcript and thus results in an increased production of the desired protein.
[0014] In a first aspect the present invention provides a method to increase the production of a desired peptide in a cell by increasing the half-life of the mRNA transcript from the gene encoding the peptide, said method characterized in that one or more slowly translated codons are introduced in the gene 45 or more codons down-stream of the start site of the open reading frame, wherein the one or more slowly translated codons are selected so that the encoded amino acid sequence of the peptide is unchanged as compared to the wild type peptide.
[0015] In a preferred embodiment of the present invention the one or more slowly translated codons are introduced in the gene at 45-90, preferably 45-88, more preferably 45-72, and most preferably 45-66, codons down-stream of the start site of the open reading frame.
[0016] Preferably the one or more slowly translated codons are selected from codons that are translated with a rate of less than 6 codons per sec.
[0017] A preferred cell is a microorganism selected from the group consisting of bacteria, fungi and algae. In a particularly preferred embodiment the microorganism is E. coli . Concerning the gene to be translated the preferred gene is lacZ gene.
[0018] Another preferred microorganism is a Bacillus e.g. B. Subtilis, B. megaterium, B. thuringiensis . Still another preferred microorganism is a fungal cell e.g. Saccharomyces cerevisiae, Pichia pastoris, Pichia methanolica, Aspergillus Niger, Aspergillus japonicus
[0019] In another embodiment of the present invention the cell is a plant cell e.g. Arabidopsis species, Tobacco species, Medicago species. Alternatively the cells are mammalian cells, e.g. Chinese hamster ovary cells, HeLa cells, hybridoma cells.
[0020] In a second aspect the present invention provides a method of increasing the half-life of a mRNA transcript from a gene encoding a peptide, said method characterized in that one or more slowly translated codons are introduced in the gene 45 or more codons down-stream of the start site of the open reading frame, wherein the one or more slowly translated codons are selected so that the encoded amino acid sequence of the peptide is unchanged as compared to the wild type peptide. Preferably, the one or more slowly translated codons are introduced in the gene 45-90 preferably 45-88, more preferably 45-72, and most preferably 45-66, codons down-stream of the start site of the open reading frame. In a very preferred embodiment of the present invention the one or more slowly translated codons are selected from codons that are translated with a rate of less than 6 codons per sec.
[0021] In a third aspect the present invention provides a method of decreasing the half-life of a mRNA transcript from a gene encoding a peptide, said method characterized in that one or more slowly translated codons are introduced in the gene 20 or less codons down-stream of the start site of the open reading frame, wherein the one or more slowly translated codons are selected so that the encoded amino acid sequence of the peptide is unchanged as compared to the wild type peptide. Preferably, the one or more slowly translated codons are introduced in the gene 1-20, preferably 4-18, more preferably 5-15, and most preferably 6-15, codons down-stream of the start site of the open reading frame.
[0022] Additionally the present invention provides a recombinant vector for increasing the production of a desired peptide in a cell, said vector comprising a DNA sequence encoding the peptide, wherein the DNA sequence has an open reading frame with one or more slowly translated codons introduced 45-72 codons down-stream of the start site of the open reading frame, said one or more slowly translated codons being selected so that the encoded amino acid sequence of the peptide is unchanged as compared to the wild type peptide.
[0023] Further the present invention provides a recombinant vector for decreasing the half-life of a mRNA transcribed from the vector encoding a peptide, said vector comprising a DNA sequence with an open reading frame having one or more slowly translated codons introduced 20 or less codons down-stream of the start site of the open reading frame, wherein the one or more slowly translated codons are selected so that the encoded amino acid sequence of the peptide is unchanged as compared to the wild type peptide.
[0024] There is also provided host cells transformed with the vectors of the present invention.
[0025] Hence the concept of the present invention is to alter codons either before codon 20 or immediately after codon 45 in such a way that codons 20-45 of the mRNA region become either more or less covered with ribosomes. This will stabilize or destabilize the mRNA. To stabilize the mRNA the codon changes should make the codons immediately after codon 45 slower translated compared to the wild type reference; to further stabilize the mRNA the codons before codon 20 may be faster translated. To destabilize the mRNA the codon changes should make the codons before codon 20 slower translated; to further destabilize the mRNA the codons after codon 45 may be faster translated. Also, the codons in the region 20-45 may be changed to faster codons in the case where a mRNA should be destabilized to remove possible ribosome queues in this region.
[0026] Concerning the quickly translated codons these are herewith defined as codons that are translated with a rate of more than 8 codons per sec.
[0027] The present method of decreasing the half-life of a mRNA transcript may be useful in a number of situations where the reduction of protein titre is of paramount importance:
1) As an alternative to anti-sense mRNA and/or gene knock outs—in case of metabolically important proteins which are essential for the health/operation of the cell but eventually suppress the metabolic pathway. 2) As a method of gene therapy whereby key genes which are over-expressing and which are difficult/impossible to down-regulate are compensated for by replacement with genes engineered to have mRNA with a much lower half-life. 3) By combining a destabilised gene which produces mRNA with poor stability to give a “trickle” of protein with a second copy of the gene which is inducible and produces highly stable mRNA to give high yield of product.
DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 shows modelling of the ribosome occupancy when translating the first 200 codons in variants of the lacZ mRNA. Panels (a to d) show the fraction of the time each codon is covered by a ribosome for the lacZ variant in: (a) pIV18; (b) pIV1; (c) pCNP1 and (d) pCNP 6 having functional half-lives of 380 sec, 240 sec, 117 sec and 28 sec, respectively. The location of slowly, medium and rapidly translated codons are indicated. The corresponding right panels give the percent of the time a window of 5 codons is free at varying positions of the gene.
[0032] FIG. 2 shows correlation between mRNA half-life and the ribosome occupancy of an early part of the mRNA. The mRNA half-life is plotted as a function of the fraction of the time the mRNA from codon 27 to 31 is uncovered by ribosomes. Filled circles, values for the ten lacZ variants used to find the correlation. The values for ribosome occupancy and half-life for the new constructs with either slowly translated codons (one or two of the codons AGG, CGG, GGA see Supplementary Material FIG. S 2 for the sequence) at codon 16 or at codon 42; 42, 43, 44 and 42, 43, 44, 45, 46 with half-lives of 26, 116, 120 and 136 respectively see FIG. 3 , are indicated on the figure as open circles. The half-life of the reference variant pMAP217 and of pMAP*** with the Shine-Dalgarno sequence from tufA in pIV1 and 5 slow codons at codon 42, 43, 44, 45, 46 is also indicated (open circles).
[0033] FIG. 3 shows determination of the functional half-lives of the new lacZ variants constructed to test the model.
[0034] FIG. 4 shows unoccupied codons in a window of 5 codons along the first 100 codons in the lacZ wild type (green, t 0.5 =113* sec) or in variants with slowly translated codons at codon 16, 17 and 18 (red, t 0.5 =26 sec) or at codon 42 (blue, t 0.5 =116 sec); at codon 42, 43, 44 (violet, t 0.5 =120 sec) or at codon 42, 43, 44, 45, 46 (turquoise, t 0.5 =136 sec). The two vertical lines indicate the mRNA segment from codon 20 to 50.
[0035] FIG. 5 shows the modelled ribosome occupancies for the ompA mRNA (top) and the bla mRNA (bottom) plotted as in FIG. 1 .
[0036] FIG. 6 shows a fraction of total protein that is LacZ protein, plotted as a function of the mRNA half-life (in seconds). In the experiment 35S methionine was incorporated in the growing strains, induced for lacZ expression, and samples were taken after 15, 30 and 45 min. These samples were analyzed on a normal 7.5% SDS-PAGE gel and the amount of LacZ protein and of two proteins, rpoBC that constitutes about 1% of total protein was determined by scanning a PhosphoImager picture of the gel. In the figure the ordinate is the LacZ/rpoBC ratio.
[0037] FIG. 7 shows the results from an experiment with CHO cells. pcDNA4/TO containing either wild type GFP construct, stabilized GFP construct, or destabilized construct were used without pcDNA6/TR. This leads to constitutive expression from transfection, and until the plasmids are lost from culture. The results are averages form two measurements from the same culture.
[0038] FIG. 8 shows CHO cell cultures transfected with pcDNA6/TR and pcDNA4/TO containing either wild type GFP, stabilized GFP, or destabilized GFP construct. Expression was induced by tetracycline addition for 24 h. (just after “day 1 samples” were taken). Two cultures are made for each construct (wt1 and wt2 are two individual cultures etc.).
[0039] FIG. 9 is based on the same data as FIG. 8 , averages from (the two) cultures for each construct is used. In this chart is also included a (single) negative control (pcDNA4/TO).
[0040] FIG. 10 shows a growth curve for an induction experiment with B. subtilis.
[0041] FIG. 11 shows a growth curve for a second induction experiment with B. subtilis.
[0042] FIG. 12 shows protein lysates were analyzed by SDS-PAGE in order to visualize the expression of eGFP.
[0043] FIG. 13 shows expression of eGFP in the different expression constructs.
[0044] FIG. 14 shows qPCR analysis of eGFP mRNA levels in B. subtilis.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Variations in the translation rate of individual codons along an mRNA may cause ribosomes to collide, for instance if slowly translated codons are preceded by rapidly translated codons. The probability of collisions is expected to rise dramatically with the translation initiation frequency. Changes in either the Shine-Dalgarno sequence or in the mRNA coding sequence might therefore affect ribosome spacing quite far from the sequence change itself. To model the distribution of ribosomes along the mRNA in detail the inventors have included additional features to our previous model and applet (Mitarai et al, 2008), which allow for an analysis of the fraction of time a codon is occupied by a ribosome and the fraction of time a specified stretch of mRNA is not masked by ribosomes and therefore possibly accessible for nucleases. The codon specific translation rates used in this modelling were fast (A), middle (B) and slow rate codons (C), translated with a rate of 35; 8; and 4.5 codons per sec, respectively. These values reproduce all our previous determinations of the translation rate in living cells and are therefore a good approximation to the rates used by E. coli (Mitarai et al, 2008).
[0046] The inventors first analyse how varying local translation rates will affect the ribosome spacing (FIG. S 1 in the Supplementary Materials section). As expected, an even distribution of the fast, average and slowly translated codons leads to an even ribosome spacing; rapidly translated codons located before a stretch of slowly translated codons will be almost totally covered by ribosomes whereas fast codons after a stretch of slowly translated codons will be covered by only few ribosomes. In the three extreme examples given in FIG. S 1 the fast-translated codons are covered with ribosomes in 43%, 98% or 8% of the time, respectively.
[0047] To analyse more natural mRNAs the inventors turned to the 8 variants of the lacZ mRNA described by Petersen (1987). Here, short sequences inserted between codon 5 and 10 in the lacZ mRNA were found to decrease the mRNA half-life two- to four fold. Also, the inventors analyse translation of lacZ in the two plasmids pIV18 and pIV1 where the lacZ ribosome-binding site was substituted with sequences from highly expressed genes expected to give a stronger ribosome binding compared to lacZ (Vind et al 1993). To be able to model the ribosome spacing on these two mRNA variants the inventors estimated the AG values for the interaction between the Shine-Dalgarno sequences in pIV18 and pIV1 and the 3′ end of 16S ribosomal RNA as described by Freier et al 1986. The interaction affects the off-rate and therefore the resulting on-rate by being proportional to e ΔG/RT . Using this formula, the relative resulting on-rates can be estimated to 1: 18*: 21* for lacZ wild type, tufA and the −9G mutant rpsA mRNA that resulted in a two-respectively three-fold increase in the mRNA half-life for the two latter variants (Vind et al 1993). All together the inventors therefore model data from a total of ten variants in the early lacZ mRNA sequence that experimentally has been shown to give a more than ten-fold change in the functional mRNA half-life. These lacZ variants are all carried on pMLB1034 (Shultz et al 1982) as are the plasmids used by Sørensen and Pedersen (1991) that provided the data that Mitarai et al (2008) modelled to determine the precise rate of initiation for translating the lacZ mRNA 1 initiation per 2.3 sec. Furthermore, all determinations of the functional half-lives were done under the same conditions (same background strain, temperature and growth medium) and the residual syntheses of β-galactosidase were followed after removal of the inducer by filtration and thus without using rifampicin to block the general transcription.
[0048] Modelling with these parameters show that the resulting initiation rates for lacZ mRNA translation in the plasmids pIV18 and pIV1 should be only marginally increased, by 14* or 4*% respectively, relative to the lacZ wild type initiation rate, in good agreement with the experimentally determined values (Vind et al 1993). This is due to the time it takes to translate the first eleven codons that constitutes a ribosome diameter. The presence of a ribosome here prevents binding of the following ribosome and prevents the binding-site to be used to its full capacity.
[0049] Typical read-outs from the applet for four of these lacZ variants are shown in FIG. 1 . As seen from the figure all show large variations in the occupancy that result from the distribution of rapidly and slowly translated codons. Similar large variations in ribosome occupancy are also seen in most mRNAs where the codons in the early lacZ region were scrambled randomly (not shown). Examining these read-outs show that varying the initiation frequency or having different translation rates of the codons inserted between codon 5 and 10 in the wild type sequence does indeed affect the ribosome spacing further downstream as suggested by FIG. S 1 . Scrutiny of FIG. 1 reveals significant changes in the degree of occupancy up to about 50 codons from the sequence change after which the occupancy becomes the same. FIG. 1 also illustrates that the more stable mRNAs have a higher ribosome density on the initial part of the mRNA. In the right panels of FIG. 1 , a window of five codons was moved down the mRNA and the fraction of time where these five codons were uncovered by ribosomes was estimated and plotted. For all ten lacZ variants and for the region from approximately codon 20 to codon 45, the inventors find a correlation between the fraction of time the 5 codons are uncovered and the mRNAs functional half-life. For other parts of the mRNA the correlation is not found (data not shown, but see FIG. 4 ). The best correlation the inventors find for the mRNA stretch from codon 27 to 31, and FIG. 2 show this for all ten mRNAs that were used to find the correlation.
[0050] The results indicate that ribosome occupancy of this early region of the mRNA should be of special importance for the mRNA half-life. Thus, the model predicts that insertion of slowly-translated codons before codon 20 in the wild type lacZ gene should decrease the functional stability because this specific region of the mRNA then would be less unoccupied by ribosomes. Similarly, insertions of slowly translated codons after codon 45 should increase the stability because ribosomes would form a queue behind these slowly translated codons and protect the region. These predictions were tested experimentally. As described in Methods, the inventors constructed the lacZ variants in pSN4 where the normal codons at position 16, 17 and 18 were exchanged with the slowly translated codons AGG CGG GGA.
[0051] Similarly, in the lacZ variants in pMAP210, pMAP211 and pMAP212 the normal codons at position 42; 42, 43, 44; or 42, 43, 44, 45 and 46 were replaced with the slowly translated codons AGG; AGG CGG GGA or AGG CGG GGA AGG CGG, respectively. Finally, the inventors constructed pMAPZZZ* and pMAPXXX where the stronger tufA Shine-Dalgarno sequenced from pIV1 replaced the normal lacZ Shine-Dalgarno region in pMAP211 and in pMAP212.
[0052] The wild type lacZ gene contains two slowly translated codons at position 31 and 32. In the three five variants with slowly translated codons inserted downstream of codon 42 the mRNA stability should be affected only slightly according to the model because it is difficult to create a bottleneck after another bottleneck. In order to distinguish the expected small changes in the mRNA half-lives, the inventors needed to improve the accuracy in the experiments. This was achieved by performing the half-life determinations on a mixture of two cultures: the lacZ variant to be tested and a lacZ reference variant. For each such experiment the time of sampling, temperature and other experimental conditions were therefore identical. As the internal reference the inventors used a culture contained a lacZ variant with an insert of 36 GAA codons at position 927 in lacZ, coding for a β-galactosidase protein with a higher molecular weight. As shown in FIG. S 2 in the Supplementary Materials section, this allowed separation of the two β-galactosidase proteins by one-dimensional SDS gel electrophoresis.
[0053] The functional half-life of these new lacZ mRNA variants was measured as previously described (Petersen, 1987) and shown in FIG. 3 , normalized to the internal reference. The average half-life of the reference construct was 110 sec, identical to the wild-type lacZ mRNA half-life of 113 sec (Petersen, 1987). The inventors observed a considerable variation from experiment to experiment in the range of 93 sec to 116 sec for this reference mRNA and a similar variation for the other mRNAs. The early slowly translated codons in pSN4 destabilized the mRNA four-fold. Altering the sequence late in the coding region at codon 927 in pMAP217 was modelled to create a stretch of ribosome-free mRNA longer than that in pSN4 but as seen from FIG. 3 such distal ribosome-unoccupied mRNA region had little, if any influence on the mRNA functional half-life. In contrast, exchange of 1, 3 or 5 codons with slowly translated codons increased the mRNA functional half-life by approximately 5, 9 and 23%. Finally, the inventors modelled the ribosome occupancy along the mRNA for these five variants. FIG. 4 show that the occupancy in the region from codon 20 to 45 closely follows the functional half-life. Specifically, the ribosome-occupancy from codon 27 to 31 was calculated for the new lacZ variants and these results included in FIG. 2 (open circles). As seen, these measured functional half-lives correspond well to the predicted values. The reciprocal value of the experimentally determined half-lives and the fraction of time the mRNA from codon 27-31 were free, was plotted as shown in the supplementary materials FIG. S 3 . The inventors see that the points within experimental error now lie on a straight line extrapolating through (0,0) that is the mRNA fully covered with ribosomes and with an infinitely high half-life. If our model described the lacZ mRNA degradation only partially, this plot should not extrapolate to (0,0) because the additional degradation mechanism (s) would be active at a completely ribosome-covered mRNA.
[0054] Finally, the inventors tried to see if our model had relevance for other mRNAs for which the functional half-life had been determined for instance for the OmpA and Lpp mRNAs that have an above average stability. However, the functional mRNA half-life of many membrane protein mRNAs is influenced by complex formation to small RNAs (Guillier et al 2006, Bossi and Figueroa-Bossi 2007). In the case of ompA the stability of the mRNA is modulated by binding of small RNA species to the untranslated 5′ end of the mRNA (Rasmussen et al, 2005). The proposed binding site is close to the ribosome-binding site and the binding of such small RNAs to the mRNA might therefore be influenced by the ribosome occupancy, but our model only describes occupancy in the translated part of the mRNA. However, mainly due to the strong Shine-Dalgarno interaction, the ompA mRNA should have a high density of ribosomes in its early coding region. The same holds for the rather stable bla mRNA (Nilsson et al 1984). With these caveats the inventors have modelled translation of the ompA and bla mRNA and the result shown in FIG. 5 . Modelling the fraction of the time the codon 27*-31* mRNA is accessible by the applet for the bla and ompA mRNAs give values of between 10% and 20% which according to FIG. 2 would indicate mRNA half-lives above average for these two mRNAs in agreement with the experimental values.
[0055] Construction of Plasmids.
[0056] All the new lacZ variants were constructed by recombineering using single stranded oligoes with 35 base homologies on both sides of the sequence alteration using the plasmids pMAS2 or pIV1 (Sørensen and Pedersen, 1991, Vind et al 1993) as template and in E. coli HME70 essentially as described (Thomason et al., 2005; Sharan et al 2009). First a TAG stop codon was introduced in lacZ at position 13 or 42. After overnight incubation in rich medium at 30° C. with agitation, the culture was spread on plates containing 100 μg ampicilin and 40*μg 5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside (X-Gal) per ml to screen for cells containing a defective lacZ gene on either pMAS2 or pIV1. White colonies were cross-streaked with phage Φ80supF that restores the activity of lacZ amber mutants. The presence of the TAG stop codon at the desired positions was verified by sequencing. The desired codon changes were again done by recombineering, screening for blue colonies on plates containing 100 μg ampicilin and 40*μg X-Gal per ml.
[0057] The plasmid pMAP217 with an insert of 36 GAA codons at position 927 in lacZ was constructed by first introducing an unique XhoI restriction site at position 927 by recombineering in lacZ on pMAS2. A 146 base long oligo containing thirty-six GAA codons was used to produce a double stranded DNA fragment with XhoI restriction site in both ends. The 146 base pair DNA fragment was cloned using the Zero Blunt TOPO PCR Cloning Kit (Invitrogen). The resulting plasmid was digested with XhoI and the 123 base pair XhoI DNA fragment was cloned in XhoI restricted pMAP201. The sequences of all plasmids constructed here are given in FIG. S 2 .
[0058] DNA Techniques.
[0059] Oligoes were supplied by DNA Technology A/S Denmark. Plasmid DNA was isolated using the Qiagen Plasmid kit. Eurofins MWG Operon, Germany performed DNA sequencing.
[0060] As mentioned above the present invention relates to DNA sequences containing mRNA stabilizing (or destabilizing) sequences and which upon transcription by a cell result in stabilized (or destabilized) mRNA transcripts, as well as to transformed microorganisms comprising such DNA sequences.
[0061] The use of such DNAs or stabilized mRNA transcripts in a method to increase the stability of mRNA transcripts of one or more genes that generate multiple mRNA transcripts and that are located on a chromosome, plasmid or any other self-replicating DNA molecule, or a method to increase the production of a desired chemical compound by a transformed microorganism, respectively, are objects of the present invention.
[0062] The term “cell” means a eukaryotic or prokaryotic cell.
[0063] The term “microorganism” means a microscopic, self-reproducing, respiring organism including, but not limited to, bacteria, fungi (including yeast) and algae. The term bacteria includes both Gram-negative and Gram-positive microorganisms. Examples of Gram negative bacteria are any from the genera Escherichia, Gluconobacter, Rhodobacter, Pseudomonas , and Paracoccus . Gram-positive bacteria are selected from, but not limited to any of the families Bacillaceae, Brevibacteriaceae, Corynebacteriaceae, Lactobacillaceae, and Streptococaceae and belong especially to the genera Bacillus, Brevibacterium, Corynebacterium, Lactobacillus, Lactococcus and Streptomyces . Among the genus Bacillus, B. subtilis, B. amyloliquefaciens, B. licheniformis and B. pumilus are preferred microorganisms in the context of the present invention. Among Gluconobacter, Rhodobacter and Paracoccus, G. oxydans, R. sphaeroides and P. zeaxanthinifaciens are preferred, respectively. Examples of yeasts are Saccharomyces , particularly S. cerevisiae . Examples of preferred other fungi are Aspergillus niger and Pencillium chrysogenum.
[0064] While the method of the present invention will be described in detail with respect to the expression of beta-galactosidase one skilled in the art will recognize that this method can be applied universally to increase the production of any protein to be synthesized by both prokaryotic (e.g. bacteria) and eukaryotic (e.g. fungi, plant and animal) cells.
Example 1
[0065] By mathematical modelling, the inventors have analysed how the translation rate of individual codons influence the spacing of ribosomes on an mRNA. The inventors have focused on modelling ribosome trafficking in the early part of the coding region because breakdown of the mRNA takes place from the 5′ end (Jacquet and Kepes, 1971, Cannistraro and Kennell, 1985) and because sequence changes here affect the half-life (Petersen, 1987; Yarchuk et al 1992; Vind et al, 1993). The inventors found a clear correlation between the mRNAs functional half-life and the ribosome occupancy in the coding region of the mRNA from approximately codon 20 to 45.
[0066] The results presented in FIG. 2 were done analysing the occupancy of the mRNA from codon 27 to codon 31 that gives the best correlation to the mRNA half-life but other mRNA stretches as for example the stretch from codon 20 to 25 or from codon 25 to 40 give results that are only slightly different. However, it is only for this initial part of the coding region from approximately codon 20 to 45 such correlation can be observed, see FIG. 4 .
[0067] As modelled previously (Mitarai et al 2008) there is a denser packing of the ribosomes early on the mRNA because of the higher density of slowly translated codons here (Bulmer 1988). Ribosomes initiate once per 2.3 seconds and physically cover about 11 codons. Therefore, the mRNA segment from codon 20 to 45 will often represent the space between the two ribosomes closest to the 5′ end of the mRNA at any time.
[0068] The degradosome model for degradation of mRNA (reviewed by Deana and Belasco, 2005) has the initial event being an endonucleolytic cut of the mRNA between two translating ribosomes as one of the options. The inventors do not think that such initial cut takes place for the following reason: If the cut were between the first two ribosomes, the ribosome preceding the cut would be expected to have its nascent peptide released as a tagged peptide by the tmRNA mechanism (Keiler et al 1996). The average mRNA is translated approximately 30 times (discussed by Mitarai et al 2008). A mechanism involving a cut between ribosomes would result in the release of 3% or more of all nascent peptides in the tagged unstable version. In addition to being wasteful, such release is an order of magnitude higher than the estimated amount of tagged peptides: 0.4% of the total number of nascent peptides (Moore and Sauer 2005).
[0069] The inventors therefore propose that the current model for mRNA degradation incorporate ribosome occupancy as follows: a component of the degradosome containing the RppH enzyme binds to an unoccupied part of the mRNA. Because slowly translated codons are overrepresented in the early part of the mRNA the distance from codon 20 to 45 are often free because ribosomes initiate 2.3 sec apart. Now, ribosome 1 releases the degrading enzyme complex in the proximity to the 5′ end. The degradosome will now either bind to a new target where it can not interact with a 5′-triphosphate group or the RppH enzyme will convert the nearby 5′ triphosphate to a mono-phosphate that destabilizes the mRNA (Celesnik et al 2007, Deana et al 2008). An interesting point in these speculations is whether the mRNA degradation machinery actually needs to be activated by a translating ribosome, in particular because the length of the 5′UTR and mRNA stability seem not to correlate and because other cellular RNA with exposed 5′ mono-phosphate groups as for example tRNA are normally very stable. Evidently and unfortunately, modelling cannot elucidate such specific biochemical mechanisms.
[0070] Because the inventors have mainly modelled mRNAs that are almost identical the inventors cannot exclude that additional parameters such as the mRNA length, sequence and structure also influences the stability.
[0071] Our analysis of the ribosome spacing is dependent on a correct estimate of the resulting on-rate. As mentioned above, the plasmids used by Petersen, (1987) all had the same Shine-Dalgarno sequence and the same first five codons in the coding region. For the plasmids pIV1 and pIV18 with a presumed higher affinity for the initiating 30S ribosome, the inventors tested the robustness of our determination of the spacing by using resulting on-rates that were two-fold above and two-fold below the values the inventors have used, estimated as described by Freier et al (1987). These results are indicated on FIG. S 3 (open triangle symbols***). As seen, these up to four-fold changes in the on-rates had only a minor influence on the modelled ribosome spacing on the first part of the mRNA and did only slightly change the correlation between the half-life and the fraction of the time this mRNA stretch is accessible.
[0072] In most other cases, it is not possible to investigate whether the more stable natural mRNAs are more occupied by ribosomes compared to the unstable natural mRNAs because the inventors lack information about on-rate for translation initiation or about the functional half-lives. Modelling of the natural mRNAs for which the inventors previously had determined the half-life (Pedersen et al 1978) is also difficult because these experiments were carried out in an E. coli B strain, with a yet incompletely sequenced genome and where the concentration of initiation-competent ribosomes might be different. Furthermore, many of the functional half-lives determined in this study were ribosomal protein mRNAs where translational coupling ensures that the on-rate for translating these mRNAs cannot be calculated directly from the Shine-Dalgarno interaction. The interaction between small regulatory RNAs and the initiation region (Bossi and Figueroa-Bossi, 2007) also makes it difficult to evaluate if for instance the functional mRNA half-lives determined by Yarchuk et al, (1992) are as predicted by our model.
[0073] The study of Ringquist et al, (1992) provided a detailed study of how varying the Shine-Dalgarno interaction affected lacZ expression. However, no functional half-life was measured directly in this study. It is therefore not known if the observed effects on lacZ expression were because of an altered on-rate for translation initiation, an altered on-rate that changed the mRNA half-life, or an altered transcriptional polarity. These data are not in contradiction to our model because as found for the pIV1 and pIV18 mRNAs and for the mRNAs it is very likely that they resulted from an altered on-rate that changed the mRNA half-life via an influence on the ribosome spacing.
[0074] Several examples are known where a specific mRNA sequence has an effect on the mRNA half-life. One example of this is the finding that a ribosomal protein S1-binding AU rich mRNA sequence can stabilize an mRNA (Komarova et al (2005). According to our modelling, the mechanism behind the mRNA stabilization of this sequence might well be that avid binding to ribosomal protein S1 to such mRNA sequence increases the on-rate for 30S ribosome binding and that this decreases the ribosome spacing and increases the mRNA half-life.
[0075] Mitarai et al, (2008) found that the preponderance of slowly translated codons in the 5′ end of the mRNA was a highly conserved feature and suggested that this conservation had to do with fine-tuning the translation initiation frequency or had importance for the overall ribosome efficiency. In addition, our modelling suggests that the conserved codon usage in the early part of the mRNA via differences in the translation rate of the individual codons also has evolved to provide the mRNA with a suitable functional half-life. It is a common observation that the activity of an enzyme often is insensitive to amino acid changes in the N-terminus. The β-galactosidase protein is a well-known example of this where up to the 41 N-terminal amino acids can be changed (Brickman et al, 1979) and where a plethora of fusion proteins to 5′ end of lacZ still retain enzyme activity. Also it is commonly observed that various amino acid sequences, for instance a his-tag can be added to the N-terminus of various enzymes without disturbing the function of the protein. It is therefore conceivable that genes frequently have close to total freedom to evolve N-termini with an amino acid usage and codon usage that results in a suitable mRNA half-life.
[0076] Finally, the inventors note that the distance between translating ribosomes in specific regions of the mRNA may be rate determining for degradation for at least some eukaryotic mRNAs (Lemm and Ross 2002). The mechanism in this study involved binding of proteins to the mRNA but even so, local translation rate differences may be a mechanism for governing the accessibility of components that affects mRNA degradation in all organisms.
RE EXAMPLES 2 & 3
[0077] In the below discussed Examples 2 and 3 stabilized/destabilized GFP mRNA variants are designed for expression in either CHO cells (Example 2) and Bacillus (Example 3).
[0078] The Examples aim to support the concept of the present invention, namely, to alter codons either before codon 20 or immediately after codon 45 in such a way that codons 20-45 of the mRNA region become either more or less covered with ribosomes. This will stabilize or destabilize the mRNA. To stabilize the mRNA the codon changes should make the codons immediately after codon 45 slower translated compared to the wild type reference; to further stabilize the mRNA the codons before codon 20 may be faster translated. To destabilize the mRNA the codon changes should make the codons before codon 20 slower translated; to further destabilize the mRNA the codons after codon 45 may be faster translated. Also, the codons in the region 20-45 may be changed to faster codons in the case where a mRNA should be destabilized to remove possible ribosome queues in this region.
[0079] In the case Bacillus subtilis (cf Example 3) the codon usage in highly expressed genes is shown in Table 1.
[0000]
TABLE 1
TTT phe F
41
TCT ser S
160
TAT tyr Y
36
TGT cys C
7
TTC phe F
102
TCC ser S
11
TAC tyr Y
104
TGC cys C
8
TTA leu L
107
TCA ser S
63
TAA OCH *
43
TGA OPA *
—
TTG leu L
56
TCG ser S
2
TAG AMB *
2
TGG trp W
26
CTT leu L
201
CCT pro P
97
CAT his H
40
CGT arg R
291
CTC leu L
11
CCC pro P
5
CAC his H
61
CGC arg R
141
CTA leu L
37
CCA pro P
91
CAA gln Q
142
CGA arg R
7
CTG leu L
26
CCG pro P
27
CAG gln Q
33
CGG arg R
1
ATT ile I
152
ACT thr T
168
AAT asn N
56
AGT ser S
20
ATC ile I
226
ACC thr T
5
AAC asn N
195
AGC ser S
45
ATA ile I
3
ACA thr T
112
AAA lys K
528
AGA arg R
38
ATG met M
145
ACG thr T
44
AAG lys K
115
AGG arg R
4
GTT val V
264
GCT ala A
284
GAT asp D
130
GGT gly G
241
GTC val V
51
GCC ala A
23
GAC asp D
111
GGC gly G
93
GTA val V
175
GCA ala A
147
GAA glu E
340
GGA gly G
158
GTG val V
50
GCG ala A
68
GAG glu E
103
GGG gly G
10
[0080] In the case of CHO cells (cf Example 2) the codon usage in highly expressed genes is shown in Table 2.
[0000]
TABLE 2
TTT phe F
9
TCT ser S
11
TAT tyr Y
7
TGT cys C
5
TTC phe F
7
TCC ser S
7
TAC tyr Y
11
TGC cys C
1
TTA leu L
2
TCA ser S
3
TAA OCH *
1
TGA OPA *
1
TTG leu L
5
TCG ser S
2
TAG AMB *
—
TGG trp W
7
CTT leu L
6
CCT pro P
13
CAT his H
7
CGT arg R
12
CTC leu L
4
CCC pro P
8
CAC his H
8
CGC arg R
4
CTA leu L
2
CCA pro P
12
CAA gln Q
2
CGA arg R
3
CTG leu L
26
CCG pro P
—
CAG gln Q
12
CGG arg R
2
ATT ile I
20
ACT thr T
13
AAT asn N
8
AGT ser S
5
ATC ile I
16
ACC thr T
13
AAC asn N
10
AGC ser S
7
ATA ile I
3
ACA thr T
8
AAA lys K
28
AGA arg R
7
ATG met M
14
ACG thr T
—
AAG lys K
37
AGG arg R
3
GTT val V
17
GCT ala A
32
GAT asp D
16
GGT gly G
22
GTC val V
15
GCC ala A
12
GAC asp D
17
GGC gly G
18
GTA val V
6
GCA ala A
5
GAA glu E
13
GGA gly G
10
GTG val V
16
GCG ala A
3
GAG glu E
19
GGG gly G
2
[0081] The above principles and these two tables were then used to suggest codon changes that would stabilize (Example 2), respectively destabilize (Example 3) the GFP mRNA in these two expression systems, CHO and Bacillus , respectively.
Example 2
eGFP Analysis in CHO Cells
[0082] Genetic Constructions for eGFP Expression in CHO Cells.
[0083] Three different eGFP genes were designed. These are an unmodified eGFP gene (SEQ ID NO 1), a gene leading to stabilized mRNA (SEQ ID NO 4), and a gene leading to destabilized mRNA (SEQ ID NO 5). All genes were synthesized, and sequenced, by Geneart. They contain a 5′ HindIII-site and a 3′ XhoI-site, which was used for cloning in pcDNA4/TO from the T-REx system from Invitrogen (Carlsbad, Calif.).
[0084] Resulting plasmids were partly sequenced after cloning to confirm that the cloning region sequence were as predicted. Large scale plasmid preparations were made using an EndoFree Plasmid Mega kit from Qiagen (Hilden, Germany).
[0085] The GFP Wild type sequence (SEQ ID NO 1) has the following sequence:
[0000]
atg agt aaa gga gaa gaa ctt ttc act gga gtt gtc cca att ctt gtt gaa tta gat ggt gat gtt aat ggg
cac aaa ttt tct gtc agt gga gag ggt gaa ggt gat gca aca tac gga aaa ctt acc ctt aaa ttt att tgc
act act gga aaa cta cct gtt cca tgg cca aca ctt gtc act act ttc ggt tat ggt gtt caa tgc ttt gcg aga
tac cca gat cat atg aaa cag cat gac ttt ttc aag agt gcc atg cct gaa ggt tat gta cag gaa aga act
ata ttt ttc aaa gat gac ggg aac tac aag aca cgt gct gaa gtc aag ttt gaa ggt gat acc ctt gtt aat
aga atc gag tta aaa ggt att gat ttt aaa gaa gat gga aac att ctt gga cac aaa ttg gaa tac aac tat
aac tca cac aat gta tac atc atg gca gac aaa caa aag aat gga atc aaa gtt aac ttc aaa att aga
cac aac att gaa gat gga agc gtt caa cta gca gac cat tat caa caa aat act cca att ggc gat ggc
cct gtc ctt tta cca gac aac cat tac ctg tcc aca caa tct gcc ctt tcg aaa gat ccc aac gaa aag aga
gac cac atg gtc ctt ctt gag ttt gta aca gct gct ggg att aca cat ggc atg gat gaa cta tac aaa taa
[0086] The GFP modified for the mRNA being more stable (SEQ ID NO 4) has the following sequence, wherein base changes compared to the wild type are shown in upper case font:
[0000]
atg agt aaa gga gaa gaa ctG ttc act gga gtt gtc cca att ctG gtt gaa CTG gat ggt gat gtt aat
ggT cac aaa ttt tct gtc agt gga gag ggt gaa ggt gat gca aca tac gga aaa ctt acc ctt aaa ttt att
tgc act act ggG aaa cta ccC gtA ccG tgg ccC acG ctA gtc act act ttc ggG tat ggG gtA caa tgc
ttt gcg agG tac cca gat cat atg aaa cag cat gac ttt ttc aag agt gcc atg cct gaa ggt tat gta cag
gaa aga act ata ttt ttc aaa gat gac ggg aac tac aag aca cgt gct gaa gtc aag ttt gaa ggt gat
acc ctt gtt aat aga atc gag tta aaa ggt att gat ttt aaa gaa gat gga aac att ctt gga cac aaa ttg
gaa tac aac tat aac tca cac aat gta tac atc atg gca gac aaa caa aag aat gga atc aaa gtt aac
ttc aaa att aga cac aac att gaa gat gga agc gtt caa cta gca gac cat tat caa caa aat act cca att
ggc gat ggc cct gtc ctt tta cca gac aac cat tac ctg tcc aca caa tct gcc ctt tcg aaa gat ccc aac
gaa aag aga gac cac atg gtc ctt ctt gag ttt gta aca gct gct ggg att aca cat ggc atg gat gaa cta
tac aaa taa
[0087] The GFP modified for the mRNA being more unstable (SEQ ID NO 5) has the following sequence, wherein base changes compared to the wild type are shown in upper case font:
[0000]
atg agt aaa gga gaa gaa ctt ttc act ggG gtt gtc ccG att ctA gtA gaa tta gat ggG gat gtA aat
ggg cac aaa ttt tct gtc agt gga gag ggt gaa ggt gat gcT aca tac gga aaa ctG acc ctG aaa ttt
att tgc act act ggT aaa ctG cct gtt cca tgg cca aca ctG gtc act act ttc ggt tat ggt gtt caa tgc ttt
gcg aga tac cca gat cat atg aaa cag cat gac ttt ttc aag agt gcc atg cct gaa ggt tat gta cag gaa
aga act ata ttt ttc aaa gat gac ggg aac tac aag aca cgt gct gaa gtc aag ttt gaa ggt gat acc ctt
gtt aat aga atc gag tta aaa ggt att gat ttt aaa gaa gat gga aac att ctt gga cac aaa ttg gaa tac
aac tat aac tca cac aat gta tac atc atg gca gac aaa caa aag aat gga atc aaa gtt aac ttc aaa
att aga cac aac att gaa gat gga agc gtt caa cta gca gac cat tat caa caa aat act cca att ggc
gat ggc cct gtc ctt tta cca gac aac cat tac ctg tcc aca caa tct gcc ctt tcg aaa gat ccc aac gaa
aag aga gac cac atg gtc ctt ctt gag ttt gta aca gct gct ggg att aca cat ggc atg gat gaa cta tac
aaa taa
Transient Gene Expression Experiments.
Expression Experiment 1:
[0088] Plasmid pcDNA4/TO-derivatives were used to transfect CHO cells using the “FreeStyle MAX CHO expression System. These plasmids contain the TetO 2 operator, enabling regulated expression when TetR repressor is present. Since this repressor is not present in CHO FreeStyle cells, gene expression will take place in a constitutive fashion, from introduction of the plasmid (transfection), and until the plasmid is lost from culture (due to lack of replication). As a negative control pcDNA4/TO was included in the experiment. During the experiment care was taken to ensure that exactly the same amount of plasmid was used in all four cases (negative control, wild type, stabilized and destabilized), and that all four cultures were treated in parallel and exactly the same way. Samples were extracted from cultures at the day of transfection and the five following days.
[0089] Samples were used for cell counting, GFP measument using “GFP Quantification Kit, Fluorometric” from Cell Biolabs Inc. (San Diego, Calif.), and for Real-time RT-PCR (as below) on selected samples.
Expression Experiment 2:
[0090] This was carried out as described for experiment 1 with the following exceptions: The plasmid pcDNA6/TR was included in six fold excess in all transfections, as described in the instructions for the T-REx system. pcDNA6/TR encodes the TetO 2 operator, and, consequently, expression only takes place from the pcDNA4/TO-derivatives, when the inducer, tetracycline, is added to the culture. Also, in this experiment a positive control plasmid (pcDNA4/TO/lacZ) was included, and finally, two cultures were set up for each plasmid.
[0091] After transfection, cultures were allowed to grow one day before tetracycline was added (to 1 μg/mL). After one more day, tetracycline was removed by media change. Culture samples were extracted from transfection and until day five.
Results
[0092] eGFP Protein Quantification
[0093] The results of GFP quantification from experiment 1 is shown in FIG. 7 . The results are perfectly in agreement the expected results (highest yield for the stabilized and lowest yield for the destabilized construct, for all five days).
[0094] The results of GFP quantification form samples from experiment 2 are shown in FIG. 8 and FIG. 9 .
Example 3
eGFP Analysis in Bacillus subtilis
[0095] eGFP Genes for Bacillus subtilis Expression.
[0096] The first gene encoded the wild type eGFP sequence (SEQ ID NO 1), the second gene encoded an eGFP gene having a stabilized eGFP mRNA (SEQ ID NO 2), and the third gene encoded an eGFP gene having a destabilized eGFP mRNA (SEQ ID NO 3).
[0097] The GFP Wild type sequence (SEQ ID NO 1) has the following sequence:
[0000]
atg agt aaa gga gaa gaa ctt ttc act gga gtt gtc cca att ctt gtt gaa tta gat ggt gat gtt aat ggg
cac aaa ttt tct gtc agt gga gag ggt gaa ggt gat gca aca tac gga aaa ctt acc ctt aaa ttt att tgc
act act gga aaa cta cct gtt cca tgg cca aca ctt gtc act act ttc ggt tat ggt gtt caa tgc ttt gcg aga
tac cca gat cat atg aaa cag cat gac ttt ttc aag agt gcc atg cct gaa ggt tat gta cag gaa aga act
ata ttt ttc aaa gat gac ggg aac tac aag aca cgt gct gaa gtc aag ttt gaa ggt gat acc ctt gtt aat
aga atc gag tta aaa ggt att gat ttt aaa gaa gat gga aac att ctt gga cac aaa ttg gaa tac aac tat
aac tca cac aat gta tac atc atg gca gac aaa caa aag aat gga atc aaa gtt aac ttc aaa att aga
cac aac att gaa gat gga agc gtt caa cta gca gac cat tat caa caa aat act cca att ggc gat ggc
cct gtc ctt tta cca gac aac cat tac ctg tcc aca caa tct gcc ctt tcg aaa gat ccc aac gaa aag aga
gac cac atg gtc ctt ctt gag ttt gta aca gct gct ggg att aca cat ggc atg gat gaa cta tac aaa taa
[0098] The GFP modified for the mRNA being more stable (SEQ ID NO 2) has the following sequence, wherein base changes compared to the wild type are shown in lower case font:
[0000]
ATG AGc AAA GGA GAA GAA CTT TTC ACT GGA GTT GTt CCA ATT CTT GTT GAA TTA
GAT GGT GAT GTT AAc GGt CAC AAA TTT TCT GTC AGT GGA GAG GGT GAA GGT
GAT GCA ACA TAC GGA AAA CTT ACC CTT AAA TTT ATT TGC ACc ACg GGg AAg CTA
CCc GTc CCc TGG CCc ACc CTT GTC ACc ACg TTC GGT TAT GGT GTT CAA TGC TTT
GCG AGA TAC CCA GAT CAT ATG AAA CAG CAT GAC TTT TTC AAG AGT GCC ATG
CCT GAA GGT TAT GTA CAG GAA AGA ACT ATA TTT TTC AAA GAT GAC GGG AAC
TAC AAG ACA CGT GCT GAA GTC AAG TTT GAA GGT GAT ACC CTT GTT AAT AGA
ATC GAG TTA AAA GGT ATT GAT TTT AAA GAA GAT GGA AAC ATT CTT GGA CAC
AAA TTG GAA TAC AAC TAT AAC TCT CAC AAT GTA TAC ATC ATG GCA GAC AAA
CAA AAG AAT GGA ATC AAA GTT AAC TTC AAA ATT AGA CAC AAC ATT GAA GAT
GGA AGC GTT CAA CTA GCA GAC CAT TAT CAA CAA AAT ACT CCA ATT GGC GAT
GGC CCT GTC CTT TTA CCA GAC AAC CAT TAC CTG TCC ACA CAA TCT GCG CTT
TCG AAA GAT CCC AAC GAA AAG AGA GAC CAC ATG GTC CTT CTT GAG TTT GTA
ACA GCT GCT GGG ATT ACA CAT GGC ATG GAT GAA CTA TAC AAA TAA
[0099] The GFP modified for the mRNA being more unstable (SEQ ID NO 3) has the following sequence, wherein base changes compared to the wild type are shown in upper case font:
[0000]
atg agt aaa gga gaa gaa ctt ttc act gga gtC gtc ccC att ctG gtt gaG tta gat ggt gat gtt aaC
ggT cac aaa ttC tct gtT agC ggT gaA ggt gaa ggt gat gca aca tac gga aaa ctt acT ctt aaa ttt
att tgc act act ggT aaa ctT cct gtt cca tgg cca aca ctt gtc act act ttc ggt tat ggt gtt caa tgc ttt
gcg aga tac cca gat cat atg aaa cag cat gac ttt ttc aag agt gcc atg cct gaa ggt tat gta cag gaa
aga act ata ttt ttc aaa gat gac ggg aac tac aag aca cgt gct gaa gtc aag ttt gaa ggt gat acc ctt
gtt aat aga atc gag tta aaa ggt att gat ttt aaa gaa gat gga aac att ctt gga cac aaa ttg gaa tac
aac tat aac tca cac aat gta tac atc atg gca gac aaa caa aag aat gga atc aaa gtt aac ttc aaa
att aga cac aac att gaa gat gga agc gtt caa cta gca gac cat tat caa caa aat act cca att ggc
gat ggc cct gtc ctt tta cca gac aac cat tac ctg tcc aca caa tct gcc ctt tcg aaa gat ccc aac gaa
aag aga gac cac atg gtc ctt ctt gag ttt gta aca gct gct ggg att aca cat ggc atg gat gaa cta tac
aaa taa
[0100] All three genes were synthesized by Geneart (Germany) and contained 5′ BamHI and 3′ SmaI restriction sites for cloning into the IPTG inducible gene expression pHT01 from MoBiTec (Germany) (www.mobitec.com). All three eGFP genes have been sequenced as part of the quality control at Geneart.
[0101] The three genes from Geneart have the following numbers:
[0000] Geneart No 1106690; eGFP wild type for Bacillus subtilis
Geneart No 1106691; eGFP stabilized for Bacillus subtilis
Geneart No 1106692; eGFP destabilized for Bacillus subtilis
Cloning of eGFP Genes into Bacillus subtilis Expression Vector pHT01
[0102] The eGFP genes were excised from the plasmids obtained from Geneart and inserted into the BamHI/SmaI sites of the expression vector pHT01 using standard cloning procedures. The vector pHT01 is an E. coli - B. subtilis shuttle vector that allows high-level expression of recombinant proteins within the cytoplasm. The expression vector uses the strong GA-dependent promoter preceding the groESL operon of B. subtilis fused to the lac operator allowing the induction by addition of IPTG.
[0103] The ligation mixture was transformed into E. coli DH10B electro competent cells and transformants were selected on LB-agar plates containing 100 mg/l of ampicillin. Transformants containing the expected recombinant plasmids were identified by colony PCR using the two primers pHT01 P1 forward: (5′ GGGAGCGGAAAAGAATGATGTAAGCGTG 3′) and pHT01 P2 reverse: (5′ GACAAAGATCTCCATGGACGCGTGACGTG 3′). One clone from each transformation showing the expected PCR product was isolated, re-streaked and stored in glycerol as research Master Cell Bank (rMCB) with the following numbers:
[0000] UP1036; pHT01::eGFP wt/DH10B
UP1037; pHT01::eGFP stabilized/DH10B
UP1038; pHT01::eGFP destabilized/DH10B
[0104] Plasmid DNA was purified from strains UP1036, UP1037 and UP1038 using the JetStar Midiprep purification kit (Genomed, Germany). The recombinant plasmids were verified by restriction enzyme digestion and by DNA sequencing of the cloning junctions using the two primers pHT01 P1 forward and pHT01 P2 reverse. Both analyses confirmed the correct insertion of the three eGFP variants into the pHT01 vector.
[0000] Transformation of Bacillus subtilis Strain MT102
[0105] Each of the three plasmids were subsequently transformed into B. subtilis MT102 (strain provided by MoBiTec) using the transformation protocol supplied by MoBiTec. Selection was performed on LB-agar plates containing 5 mg/l of chloramphenicol. Two clones from each transformation were re-streaked and stored in glycerol as research Master Cell Bank (rMCB) with the strain numbers below. As control we transformed pHT01 into B. subtilis strain MT102 as well.
[0000] UP1032; pHT01/MT102
UP1043; pHT01::eGFP wt/MT102 clone 1
UP1044; pHT01::eGFP wt/MT102 clone 2
UP1045; pHT01::eGFP stabilized/MT102 clone 1
UP1046; pHT01::eGFP stabilized/MT102 clone 2
UP1047; pHT01::eGFP destabilized/MT102 clone 1
UP1048; pHT01::eGFP destabilized/MT102 clone 2
[0106] For the analysis of eGFP expression the four strains UP1032, UP1043, UP1045 and UP1047 were used.
Induction Experiment 1
[0107] The four strains UP1032, UP1043, UP1045 and UP1047 were grown overnight in 10 ml LB medium containing 5 mg/L of chloramphenicol at 37° C. The overnight cultures were diluted 100 fold in 100 ml fresh medium and grown (shaking 250 rpm) until OD600≈0.7-0.8, where the cultures were induced using IPTG (final concentration 1 mM). Samples (2×2.5 ml, 2×5 ml, 2×10 ml) were harvested after 2½ hours of IPTG induction. FIG. 10 shows the growth curve for this experiment.
[0108] Protein lysates were prepared using FastPrep FP120 equipment as shortly described below. The cell pellets were washed in 1 ml 1× lysis buffer (supplied in the GFP quantification kit (AKR120 from CELL BIOLABS INC), centrifuged, re-suspended in 200 μl 1× lysis buffer and then transferred to a new tube (with screw cap) containing acid washed glass beads (107 micron, SIGMA). The cell suspension was treated in the FastPrep for 25 seconds at max speed (6.5), and then rested for 1 minute on ice. This procedure was repeated three times in total. Another 150 μl 1× lysis buffer was added to the tube and the supernatants (ca 350 μl) containing the soluble protein fractions were obtained by centrifugation.
Induction Experiment 2
[0109] In this experiment the negative control strain UP1032 was omitted. This induction experiment was executed as the first experiment with few exceptions; Cultures were induced at OD600≈0.8-0.9. FIG. 11 shows the growth curve for this experiment. Only one set of cell extract preparations was performed in this experiment.
[0000] SDS-PAGE Analysis of eGFP Expression
[0110] The protein lysates were analyzed by SDS-PAGE (12% Tris-Glycin) in order to visualize the expression of eGFP. 10 μl protein lysdate was mixed with 10 μl sample buffer and loaded on the SDS-PAGE. The SDS-PAGE clearly demonstrates the expression of a recombinant protein having the expected molecular weight of eGFP (26.8 KDa). No expression is seen in the negative control lysate (UP1032; lane 2). Expression is very similar in UP1043 (wild type eGFP; lane 3) and in UP1045 (stabilized eGFP; lane 4), while the expression in UP1047 (destabilized eGFP; lane 5) is much lower ( FIG. 12 ). This pattern is independent of the two induction experiments and independent of the two protein extractions performed for the first induction experiment.
[0000] Fluorometric Quantification of eGFP
[0111] The expression of eGFP in the different expression constructs were quantified using the GFP Quantification Kit from CELL BIOLABS INC (Cat. Number AKR 120). The procedure and assay protocol were followed as described by the manufacturer of the kit. Generally the samples were diluted 10 times in lysis/assay buffer in order to be within the range of the standard curve. The fluorescence was measured using a fluorescence plate reader at 485/538 nm. Each sample was analyzed in duplicate in the plate reader. The relative fluorescence is shown in FIG. 13 .
[0112] The figure shows that the fluorescence in UP1047 (destabilized eGFP) is 4-8 times lower than the level of fluorescence in the wild type or stabilized strains (UP1043 and UP1045). The first extraction performed on the cells from induction experiment 1 showed that the stabilized eGFP variant resulted in approximately 10% higher fluorescence compared to the wild type variant; comparison of the green and red bars in strains UP1043 and UP1045. However, when the experiment was repeated using the second extract from the first induction experiment and an extract from the second induction experiment, the results were somehow inverted. Here, the fluorescence in the strain containing the wild type eGFP gene was approximately 5-15% higher than the stabilized variant; comparison of the blue and yellow bars in strains UP1043 and UP1045.
Isolation of Total RNA
[0113] Total RNA was isolated from the 10 ml cell pellets (UP1032, UP1043, UP1045, and UP1047) obtained from induction experiment 1. The Qiagen RNeasy Midi Kit was used according the instructions from the manufacturer (Handbook September 2010). Total RNA of high purity were obtained from all four strains. The specifications for the RNA are given in table 3.
[0000] TABLE 3 Strain Concentration A260/A280 Total amount (μg) UP1032 134 ng/μl 2.1 33.5 μg UP1043 110 ng/μl 2.1 27.5 μg UP1045 88 ng/μl 2.1 22.0 μg UP1047 85 ng/μl 2.1 21.2 μg
Quantification of eGFP mRNA with qPCR Analysis
[0114] The mRNA levels of eGFP in the different expression constructs were quantified using Real-time RT-PCR (qPCR). The protocol from Applied Biosystems was followed as described in Tag Man® RNA-to-C 1 TM 1-Step Kit Part No. 4392938. GFP specific primers for qPCR analysis were supplied from Applied Biosystems. FIG. 14 shows qPCR analysis of eGFP mRNA levels in B. subtilis . Fold induction normalized to control cultures.
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This application is a continuation of application Ser. No. 07/374,304, filed June 30, 1989 and now abandoned.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a novel polyorganosiloxane suitable for the modification of silicone rubbers and synthetic resins.
(2) Description of the Prior Art
Heretofore, a fluorine-containing group has been introduced into silicone rubbers for the purpose of improving oil resistance and solvent resistance. A typical example of the fluorine-containing group is a 3,3,3-trifluoropropyl group, and the fluorine-containing group is usually introduced into a pendant site (branch site of a polysiloxane chain). Such fluorosilicone rubbers have been used singly and in the form of blends and copolymers of these rubbers and ordinary silicone rubbers.
Furthermore, polyorganosiloxanes have been used in synthetic resins with the intention of providing molded articles of the synthetic resins with interfacial characteristics such as water repellency, release properties and stain resistance as well as other characteristics such as heat resistance which the polyorganosiloxanes have. In these polyorganosiloxanes, the straight-chain polysiloxanes are mainly used. The polysiloxane compound not having any group which is reactive with a synthetic resin is introduced into the synthetic resin by blending them, and the polyorganosiloxane having the group which is reactive therewith is introduced thereinto by chemical bond. The polyorganosiloxane can be also used as a raw material of graft polymers for the modification of the synthetic resin to which much attention is paid of late, and particularly in this case, the so-called monofunctional polyorganosiloxane has been used in which one terminal alone has a functional group and another terminal is terminated with an alkyl group.
However, when the fluorine-containing substituent is introduced at the pendant site as in conventional silicone rubbers, the fluorine-containing substituent is uniformly present in molded or coated products, and therefore a great deal of the fluorine-containing substituent is required to obtain the expected effect. In addition, there are also troubles due to poor miscibility and a problem such as the bad influence of the substituents on other physical properties.
Also when the polyorganosiloxane is used for the purpose of improving the specific characteristics of the, synthetic resin, the improvement depends upon the function of the polysiloxane. Thus, the degree of improvement of the synthetic resin is insufficient in view of the fact that the demand of the specific characteristics is now increased. Moreover, in order to obtain the characteristics sought, a great deal of the polyorganosiloxane is required, which leads to the problem that the other physical properties are adversely affected. The monofunctional polyorganosiloxane also has similar disadvantages, because the other terminal of the molecular chain which has no functional group for the synthetic resin is terminated with the trimethylsiloxy group. In addition, specific properties such as oil repellency are scarcely improved by the polydimethylsiloxane alone in which the other terminal is terminated with an alkyl group.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel polyorganosiloxane having a portion with a fluoroalkyl group at one molecular chain terminal thereof and a portion with a functional group at the other molecular chain terminal in its one molecule, which compound can solve the above-mentioned problems.
The present inventors have intensively conducted research to achieve the above-mentioned objects, and they have prepared polyorganoxiloxanes having at least one fluorine atom-containing substituent at an α-(α'- or α"-)position and having an unsaturated double bond-containing substituent at a ω-(ω'- or ω"-)position.
That is, the first feature of this invention is directed to a polyorganosiloxane represented by the general formula (I) ##STR5## wherein j is an integer of 1 to 2000, and R 1 is a vinyl group, allyl group, m-ethenylphenyl group, o-ethenylphenyl group, p-ethenylphenyl group, m-ethenylphenylmethyl group, o-ethenylphenylmethyl group, p-ethenylphenylmethyl group, β-(m-ethenylphenyl)ethyl group, β-(o-ethenylphenyl)ethyl group, β-(p-ethenylphenyl)ethyl group, or a substituent which is a straight-chain or branched alkenyl group having an unsaturated double bond at its terminal end represented by the formula (II)
CH.sub.2 =CHC.sub.a H.sub.2a ( II)
wherein a is an integer of 2 to 18, each of R 2 and R 3 is an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, allyl group or a substituent represented by the above-mentioned formula (II), and R 4 is a pentafluorophenyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or a substituent which is a straight-chain or branched fluoroalkyl group represented by the formula (IV)
C.sub.b H.sub.c F.sub.2b-c+1 ( IV)
wherein b is an integer of 3 to 18, and c is an integer of 0 to 2b.
The second feature of this invention is directed to a polyorganosiloxane represented by the general formula (I) regarding the first feature of this invention in which the substituent represented by R 4 is a 3,3,3-trifluoropropyl group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or heptadecafluoro-1,1,2,2-tetrahydrodecyl
The third feature of this invention is directed to a polyorganosiloxane having an at least one fluorine atom-containing substituent in its molecule and represented by the general formula (III) ##STR6## wherein each of k and l is an integer of 1 to 2000, R 1 and R 2 are the same meaning as described above, and each of R 5 and R 6 is an alkyl group having 1 to 4 carbon atoms, vinyl group, allyl group, pentafluorophenyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group, a substituent represented by the above-mentioned formula (II) or a substituent represented by the above-mentioned formula (IV) and at least one of R 5 and R 6 is a fluorine atom-containing substituent of the above-mentioned groups.
The fourth feature of this invention is directed to a polyorganosiloxane represented by the general formula (III) regarding the third feature of this invention in which at least one of the substituent represented by R 5 and R 6 is a 3,3,3-trifluoropropyl group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or heptadecafluoro-1,1,2,2-tetrahydrodecyl group.
The fifth feature of this invention is directed to a polyorganosiloxane represented by the general formula (V) ##STR7## wherein each of m, n and p is an integer of 1 to 2000, R 1 is the same meaning as described above, and each of R 7 , R 8 and R 9 is an alkyl group having 1 to 4 carbon atoms, vinyl group, allyl group, pentafluorophenyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group, a substituent represented by the above-mentioned formula (II) or a substituent represented by the above-mentioned formula (IV), and at least one of R 7 , R 8 and R 9 is a fluorine atom-containing substituent of the above-mentioned groups.
The sixth feature of this invention is directed to a polyorganosiloxane represented by the general formula (V) regarding the fifth feature of this invention in which at least one of the substituent represented by R 7 , R 8 and R 9 is a 3,3,3-trifluoropropyl group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or heptadecafluoro-1,1,2,2-tetrahydrodecyl group.
The seventh feature of this invention is directed to a polyorganosiloxane having an at least one unsaturated double bond-containing substituent in its molecule and represented by the general formula (VI) ##STR8## wherein each of q and r is an integer of 0 to 2000, and R 10 is a pentafluorophenyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or a substituent group represented by the above-mentioned formula (IV), R 11 is a substituent which is an alkyl group having 1 to 4 carbon atoms or phenyl group, each of R 12 , R 13 , R 14 and R 15 is an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, allyl group or a substituent represented by the above-mentioned formula (II), each of R 16 and R 17 is an alkyl group having 1 to 4 carbon atoms, vinyl group, allyl group, m-ethenylphenyl group, o-ethenylphenyl group, p-ethenylphenyl group, m-ethenylphenylmethyl group, o-ethenylphenylmethyl group, p-ethenylphenylmethyl group, β-(m-ethenylphenyl)ethyl group, β-(o-ethenylphenyl)ethyl group, β-(p-ethenylphenyl)ethyl group or a substituent represented by the above-mentioned formula (II), but at least one of R 12 to R 17 is an unsaturated double bond-containing group of the above-mentioned groups.
The eighth feature of this invention is directed to a polyorganosiloxane represented by the general formula (VI) regarding the seventh feature of this invention in which the substituent represented by R 10 is a 3,3,3-trifluoropropyl substituent represented group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or heptadecafluoro-1,1,2,2-tetrahydrodecyl group.
The ninth feature of this invention is directed to a polyorganosiloxane represented by the general formula (VII) ##STR9## wherein each of s, t and u is an integer of 1 to 2000, and R 10 has the same meaning as described above, each of R 18 , R 19 , R 20 , R 21 , R 22 and R 23 is an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, allyl group or a substituent which is a straight-chain or branched alkenyl represented by the above-mentioned formula (II), each of R 24 , R 25 and R 26 is an alkyl group having 1 to 4 carbon atoms, vinyl group, allyl group, m-ethenylphenyl group, o-ethenylphenyl group, p-ethenylphenyl group, m-ethenylphenylmethyl group, o-ethenylphenylmethyl group, p-ethenylphenylmethyl group, β-(m-ethenylphenyl)ethyl group, β-(o-ethenylphenyl)ethyl group, β-(p-ethenylphenyl)ethyl group or a substituent represented by the above-mentioned formula (II), but at least one of R 18 to R 26 is an unsaturated double bond-containing substituent of the above-mentioned groups.
The tenth feature of this invention is directed to a polyorganosiloxane represented by the general formula (VII) regarding the ninth feature of this invention in which the substituent represented by R 10 is a 3,3,3-trifluoropropyl group, tridecafluoro-1,1,2,2-tetrahydrooctyl group, 3-(heptafluoroisopropoxy)propyl group, 1,1,2,2-tetrafluoroethyl group or heptadecafluoro-1,1,2,2-tetrahydrodecyl group.
The eleventh feature of this invention is directed to a polyorganosiloxane represented by the general formula (I) regarding the first feature of this invention in which the substituent represented by R 1 has the formula (VIII) ##STR10## wherein X 1 is a hydrogen atom or methyl group.
The twelfth feature of this invention is directed to a polyorganosiloxane represented by the general formula (III) regarding the third feature of this invention in which the substituent represented by R 1 has the above-mentioned formula (VIII).
The thirteenth feature of this invention is directed to a polyorganosiloxane represented by the general formula (V) regarding the fifth feature of this invention in which the substituent represented by R 1 has the above-mentioned formula (VIII).
The fourteenth feature of this invention is directed to a polyorganosiloxane represented by the general formula (VI) regarding the seventh feature, of this invention in which at least one of the substituents represented by R 16 and R 17 has the above-mentioned formula (VIII).
The fifteenth feature of this invention is directed to a polyorganosiloxane represented by the general formula (VII) regarding the ninth feature of this invention in which at least one of the substituents represented by each of R 24 , R 25 and R 26 has the above-mentioned formula (VIII).
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 3 are IR charts of siloxane compounds prepared in Examples 1 to 3 of the present invention.
FIG. 4 is an IR chart of a siloxane compound prepared in Reference Example 1.
FIGS. 5 to 23 are IR charts of siloxane compounds prepared in Examples 4 to 22 of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The inventors of the present application have realized that the above-mentioned problems can be overcome by the polyorganosiloxanes just referred to.
The polyorganosiloxanes represented by the general formula (I) regarding the first feature, the general formula (III) regarding the third feature, the general formula (V) regarding the fifth feature, the general formula (VI) regarding the seventh feature and the general formula (VII) regarding the ninth feature of this invention are characterized by having a terminal portion of an unsaturated double bond-containing substituent and another terminal portion of a fluorine atom-containing substituent simultaneously in one molecule thereof, as is apparent from the above general formulae. This constitution is maintained even in the high-molecular polymer in which each value of j in the general formula (I), k and (in the general formula (III), m, n and p in the general formula (V), q and r in the general formula (VI) and s, t and u in the general formula (VII) has a great value, and each of the molecules constituting the polymer has the terminal portion of the unsaturated double bond-containing substituent and the other terminal portion of the fluorine atom-containing substituent in the one molecule thereof Additionally, the polymer of the present invention is characterized in that its dispersity is from 1.1 to 1.2 in a preferable case, which means that the distribution of the molecular weight is controlled very well.
Each value of j in the general formula (I), k and (in the general formula (III), m, n and p in the general formula (V), q and r in the general formula (VI) and s, t and u in the general formula (VII) indicates the number of dimethylsiloxane units in a polydimethylsiloxane straight-chain portion, and the value is preferably in the range of 1 to 2000 in the case of j, k, (, m, n and p, and 0 to 2000 in the case of q, r, s, t and u so as to surely exert the specific function of the polydimethylsiloxane when the polyorganosiloxane is introduced into a silicone rubber or a synthetic resin, to facilitate the introduction of the compound into the synthetic resin, and to facilitate the synthesis of the compound itself.
In the case that each polyorganosiloxane of the present invention represented by the general formula (I) regarding the first invention, the general formula (III) regarding the third invention, the general formula (V) regarding the fifth invention, the general formula (VI) regarding the seventh invention and the general formula (VII) of the ninth invention is introduced into a silicone rubber or a synthetic resin, each value of j in the general formula (I), k and (in the general formula (III), m, n and p in the general formula (V), q and r in the general formula (VI) and s, t and u in the general formula (VII) is preferably 700 or less, depending upon the kind of structure of the polyorganosiloxane of the present invention to be used, the kind of synthetic resin sought, the characteristics of the polymer and the desired function.
In the alkenyl group having the unsaturated double bond represented by the formula (II) in the first, third, fifth, seventh and ninth features of this invention, the parameter a is preferably in the range of 3 to 18 for the sake of the easy availability of a raw material, the effective exertion of function and the ease of synthesis.
Furthermore, in the fluoroalkyl group represented by the formula (IV) in the first, third, fifth, seventh and ninth features of this invention, the parameter b is preferably in the range of 3 to 18 for the sake of the easy availability of the raw material, the effective exertion of the function which the fluoroalkyl group has, and the ease of synthesis.
The polyorganosiloxanes of the present invention are characterized by the following structures. That is, on the basis of an substituent having the unsaturated double bond, the polyorganosiloxane represented by the general formula (I) regarding the first feature of this invention has one siloxane chain, the compound represented by the general formula (III) regarding the third feature of this invention has two siloxane chains, and the compound represented by the general formula (V) regarding the fifth feature of this invention has three siloxane chains. Moreover, on the basis of the fluorine atom-containing substituent, the polyorganosiloxane represented by the general formula (I) regarding the first feature of this invention has one siloxane chain, the compound represented by the general formula (VI) regarding the seventh feature of this invention has two siloxane chains, and the compound represented by the general formula (VII) regarding the ninth feature of this invention has three siloxane chains. Therefore, the above-mentioned structure of the polyorganosiloxane can be optionally selected in compliance with the kind and desired functional properties of the synthetic resin.
In the polyorganosiloxane having the plural siloxane chains represented by the above-mentioned general formula (III), (V), (VI) or (VII) of the third, fifth, seventh or ninth feature of this invention, the respective siloxane chains preferably have the same chain length in most of the cases where the polyorganosiloxane is used as a graft polymer to modify the synthetic resin. However, the polyorganosiloxane can have different molecular chain lengths in accordance with particular purpose.
The substituents represented by R 5 and R 6 in the general formula (III) and the substituents represented by R 7 , R 8 and R 9 in the general formula (V) may be different from each other, and the substituents represented by R 16 and R 17 in the general formula (VI) and the substituents represented by R 24 , R 25 and R 26 in the general formula (VII) may be also different from each other. However, except for the case where it is necessary to provide the synthetic resin with a specific function and except for the case where it is necessary to finely control the characteristics, the compound preferably has the same siloxane chain length and the same substituents, because if they are not the same, manufacturing steps increase and the tolerance of synthetic conditions is restricted.
The compound of the present invention represented by the general formula (I) of the first feature, the general formula (III) of the third feature, the general formula (V) of the fifth feature, the general formula (VI) of the seventh feature or the general formula (VII) of the ninth feature of this invention can be used as the raw material of a modifier for a silicone rubber which can be obtained by reacting the unsaturated double bond-containing substituent present in the molecule of the compound with another polyorganosiloxane containing a hydrosilyl group in the presence of a catalyst such as chloroplatinic acid, and can be also used as a polyorganosiloxane useful for the property modification of the synthetic resin, which mainly comprises an addition polymer capable of reacting with the unsaturated double bond-containing group present in the compound molecule of the present invention.
Now, reference will be made to the process for preparing the compounds of the present invention represented by the general formula (I) of the first feature, the general formula (III) of the third feature and the general formula (V) of the fifth feature of the present invention. In the first place, (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol (IX) and hexamethylcyclotrisiloxane (X) are subjected to polymerization in the presence of a butyl lithium catalyst in an amount of 0.0005 to 1 mole, preferably 0.0005 to 0.5, more preferably 0.0005 to 0.1 mole of the above-mentioned silanol (IX) (initiator) in order to produce an intermediate (formula XI), and afterward dimethylchlorosilane having the unsaturated double bond-containing substituent is added thereto as a chain terminator, thereby obtaining a polyorganosiloxane having a desired average polymerization degree and represented by the undermentioned formula (XII).
Furthermore, when triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR11## wherein Bu is a butyl group , V 1 is an integer of 1 to 1,999, and X 2 is a hydrogen atom or lithium atom.
For the intermediate represented by the formula (XI) in the preparation process, methyldichlorosilane having the unsaturated double bond-containing substituent can be used in place of dimethylchlorosilane having the unsaturated double bond-containing substituent as the chain terminator, so that a polyorganosiloxane represented by the formula (XIII) is obtained which has two siloxane chains on the basis of the silyl group, the siloxane chains being combined with the unsaturated double bond-containing substituent.
Furthermore, when triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR12## wherein V 1 is an integer of 1 to 1,999 and X 2 is a hydrogen atom or lithium atom.
Similarly, for the intermediate represented by the formula (XI), trichlorosilane having the unsaturated double bond-containing substituent can be used as the chain terminator, so that a polyorganosiloxane represented by the formula (XIV) is easily obtained which has three siloxane chains on the basis of the silyl group, the siloxane chains being combined with the unsaturated double bond-containing substituent.
Furthermore, when a triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR13## wherein V 1 is an integer of 1 to 1,999 and X 2 is a hydrogen atom or lithium atom.
Furthermore, (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol (X) which is the trialkylsilanol of the polymerization initiator can be prepared by hydrolyzing (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylchlorosilane. Examples of the trialkylchlorosilane compound include (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylchlorosilane, trimethylchlorosilane, ethyldimethylchlorosilane, n-butyldimethylchlorosilane, t-butyldimethylchlorosilane, isopropyldimethylchlorosilane, n-propyldimethylchlorosilane, pentafluorophenyldimethylchlorosilane, 3,3,3-trifluoropropyldimethylchlorosilane, (heptadecafluoro-1,1,2.,2-tetrahydroecyl)dimethylchlorosilane, 3-(heptafluoroisopropoxy)propyldimethylchlorosilane and 1,1,2,2-tetrafluoroethyldimethylchlorosilane.
As examples of the monochlorosilane compound having the unsaturated double bond-containing substituent which is used as the chain terminator in preparing the polyorganosiloxane having one siloxane chain combined with the unsaturated double bond-containing substituent, there are mentioned vinyldimethylchlorosilane, allyldimethylchlorosilane, 5-hexenyldimethylchlorosilane, 7-octenyldimethylchlorosilane, 13-tetradecenyldimethylchlorosilane, 3-methacryloxypropyldimethylchlorosilane, vinylmethylphenylchlorosilane, allylmethylphenylchlorosilane, 5-hexenylmethylphenylchlorosilane, 7-octenylmethylphenylchlorosilane, 13-tetradecenylmethylphenylchlorosilane, 3-methacryloxypropylmethylphenylchlorosilane, (m-ethenylphenyl)dimethylchlorosilane, (o-ethenylphenyl)dimethylchlorosilane, (p-ethenylphenyl)dimethylchlorosilane, [(m-ethenylphenyl)methyl]dimethylchlorosilane, [(o-ethenylphenyl)methyl]dimethylchlorosilane, [(p-ethenylphenyl)methyl]dimethylchlorosilane, [β-(m-ethenylphenyl)ethyl]dimethylchlorosilane, [β-(o-ethenylphenyl)ethyl]dimethylchlorosilane, [β-(p-ethenylphenyl)ethyl]dimethylchlorosilane, vinyldiphenylchlorosilane, allyldiphenylchlorosilane, 5-hexenyldiphenylchlorosilane, 7-octhenyldiphenylchlorosilane, 13-tetradecenyldiphenylchlorosilane and 3-methacryloxypropyldiphenylchlorosilane.
Furthermore, as examples of the dichlorosilane compound having the unsaturated double bond-containing substituent which can be used as the chain terminator in preparing the polyorganosiloxane having two siloxane chains combined with the unsaturated double bond-containing substituent, there are mentioned vinylmethyldichlorosilane, allylmethyldichlorosilane, 5-hexenylmethyldichlorosilane, 7-octenylmethyldichlorosilane, 13-tetradecenylmethyldichlorosilane, 3-methacryloxypropylmethyldichlorosilane, vinylphenyldichlorosilane, (m-ethenylphenyl)methyldichlorosilane, (o-ethenylphenyl)methyldichlorosilane, (p-ethenylphenyl)methyldichlorosilane, [(m-ethenylphenyl)methyl]methyldichlorosilane, [(o-ethenylphenyl)methyl]methyldichlorosilane, [(p-ethenylphenyl)methyl]methyldichlorosilane, [β-(m-ethenylphenyl)ethyl]methyldichlorosilane, [β-(o-ethenylphenyl)ethyl]methyldichlorosilane, [8-(p-ethenylphenyl)ethyl]methyldichlorosilane, allylphenyldichlorosilane, 5-hexenylphenyldichlorosilane, 7-octhenylphenyldichlorosilane, 13-tetradecenylphenyldichlorosilane and 3-methacryloxypropylphenyldichlorosilane.
As examples of the trichlorosilane compound having the unsaturated double bond-containing substituent which can be used as the chain terminator in preparing the polyorganosiloxane having three siloxane chains combined with the unsaturated double bond-containing substituent, there are mentioned vinyltrichlorosilane, allyltrichlorosilane, 5-hexenyltrichlorosilane, 7-octenyltrichlorosilane, 13-tetradecenyltrichlorosilane, (m-ethenylphenyl)trichlorosilane, (o-ethenylphenyl)trichlorosilane, (p-ethenylphenyl)trichlorosilane, [(m-ethenylphenyl)methyl]trichlorosilane, [(o-ethenylphenyl)methyl]trichlorosilane, [(p-ethenylphenyl)methyl]trichlorosilane, [β-(m-ethenylphenyl)ethyl]trichlorosilane, [β-(o-ethenylphenyl)ethyl]trichlorosilane, [β-(p-ethenylphenyl)ethyl]trichlorosilane and 3-methacryloxypropyltrichlorosilane.
Now, reference will be made to one example of the preparation of the polyorganosiloxane represented by the general formula (I) of the first feature, the general formula (VI) of the seventh feature, and the general formula (VII) of the ninth feature of the present invention. In the first place, the vinyldimethylsilanol (XI) is polymerized with hexamethylcyclotrisiloxane (X) in the presence of a butyl lithium catalyst in an amount of 0.0005 to 1 mole, preferably 0.0005 to 0.5 mole, more preferably 0.0005 to 0.1 mole per mole of the above-mentioned silanol (IX) (initiator), and (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylchlorosilane is then added thereto as a chain terminator, thereby obtaining a polyorganosiloxane having a desired average polymerization degree and represented by the undermentioned formula (XVII).
Furthermore, when a triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR14## wherein Bu is a butyl group, V 2 is an integer of 1 to 1,999, and X 2 is a hydrogen atom or lithium atom.
For the intermediate represented by the formula (XVI), methyldichlorosilane having the fluorine atom-containing substituent can be substituted for dimethylchlorosilane having the fluorine atom-containing substituent as the chain terminator, so that a polyorganosiloxane represented by the undermentioned formula (XVIII) is obtained which has two siloxane chains on the basis of the silyl group, the siloxane chains being combined with the fluorine atom-containing substituent.
Furthermore, when a triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR15## wherein V 2 is an integer of 1 to 1,999 and X 2 is a hydrogen atom or lithium atom.
Similarly, for the intermediate represented by the formula (XVI), trichlorosilane having the fluorine atom-containing substituent can be used as the chain terminator, so that a polyorganosiloxane represented by the undermentioned formula (XIX) is obtained which has three siloxane chains on the basis of the silyl group, the siloxane chains being combined with the fluorine atom-containing substituent.
Furthermore, when a triethylamine is used in the above-mentioned reaction with the chlorosilane, this reaction can proceed more inevitably. ##STR16## wherein V 2 is an integer of 1 to 1,999 and X 2 is a hydrogen atom or lithium atom.
Furthermore, vinyldimethylsilanol (XV) which is the alkenyldialkylsilanol of the polymerization initiator can be prepared by hydrolyzing vinyldimethylchlorosilane. Examples of the alkenyldialkylchlorosilane compound include vinyldimethylchlorosilane, allyldimethylchlorosilane, 5-hexenyldimethylchlorosilane, 7-octenyldimethylchlorosilane, 13-tetradecenyldimethylchlorosilane, vinylmethylphenylchlorosilane, allylmethylphenylchlorosilane, 5-hexenylmethylphenylchlorosilane, 7-octenylmethylphenylchlorosilane, 13-tetradecenylmethylphenylchlorosilane, (m-ethenylphenyl)dimethylchlorosilane, (o-ethenylphenyl)dimethylchlorosilane, (p-ethenylphenyl)dimethylchlorosilane, [(m-ethenylphenyl)methyl]dimethylchlorosilane, [(o-ethenylphenyl)methyl]dimethylchlorosilane, [(p-ethenylphenyl)methyl]dimethylchlorosilane, [β-(m-ethenylphenyl)ethyl]dimethylchlorosilane, [β-(o-ethenylphenyl)ethyl]dimethylchlorosilane, [β-(p-ethenylphenyl)ethyl]dimethylchlorosilane, vinyldiphenylchlorosilane, allyldiphenylchlorosilane, 5-hexenyldiphenylchlorosilane, 7-octhenyldiphenylchlorosilane, 13-tetradecenyldiphenylchlorosilane and 3-methacryloxypropyldimethylchlorosilane.
As examples of the monochlorosilane compound having the fluorine atom-containing substituent which is used as the chain terminator in preparing the polyorganosiloxane having one siloxane chain combined with the fluorine atom-containing substituent, there are mentioned (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylchlorosilane, pentafluorophenyldimethylchlorosilane, 3,3,3-trifluoropropyldimethylchlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethylchlorosilane, 3-(heptafluoroisopropoxy)propyldimethylchlorosilane and 1,1,2,2-tetrafluoroethyldimethylchlorosilane.
As examples of the dichlorosilane compound having the fluorine atom-containing substituent which is used as the chain terminator in preparing the polyorganosiloxane having two siloxane chains combined with the fluorine atom-containing substituent, there are mentioned (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethyldichlorosilane, pentafluorophenylmethyldichlorosilane, 3,3,3-trifluoropropylmethyldichlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)methyldichlorosilane, 3-(heptafluoroisopropoxy)propylmethyldichlorosilane and 1,1,2,2-tetrafluoroethylmethyldichlorosilane.
As examples of the trichlorosilane compound having the fluorine atom-containing substituent which is used as the chain terminator in preparing the polyorganosiloxane having three siloxane chains combined with the fluorine atom-containing substituent, there are mentioned (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane, pentafluorophenyltrichlorosilane, 3,3,3-trifluoropropyltrichlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane, 3-(heptafluoroisopropoxy)propyltrichlorosilane and 1,1,2,2-tetrafluoroethyltrichlorosilane.
The molecular weight of the polysiloxane can be easily controlled by adjusting amounts of the alkenyldialkylsilanol which is the initiator and hexamethylcyclotrisiloxane, in the case that the number of the dimethylsiloxane units is 2000 or less (number average molecular weight=about 150000 or less). In addition, even when the number average molecular weight is greater, the control of the molecular weight can be accomplished by changing conditions for living polymerization.
In this manner, the novel polyorganosiloxane can be prepared which has the fluorine atom-containing substituent at an α-(α'- or α"-)position and has the unsaturated double bond-containing substituent at a ω-(ω'- or ω"-)position.
When the polyorganosiloxane having the fluorine atom-containing substituent at an α-(α'- or α"-) position and the unsaturated double bond-containing substituent at a ω-(ω'- or ω"-)position is used to improve the characteristics of silicone rubbers, the density of the fluoroalkyl group can be more heightened in the surface portions of these products than in the interiors thereof, because the fluoroalkyl group is present at the molecular chain terminal which is most distant from the reactive group capable of chemically bonding to the silicone rubber, and the degree of freedom of the fluoroalkyl group is higher than in the case in which the fluoroalkyl group is present on the pendant site. To sum up, the compound of the present invention can obtain the great improvement effect of the surface characteristics under a influence of the small amount of the fluoroalkyl group in contrast to the conventional compound in which the fluoroalkyl group exists only in the pendant portion, and the molecular chain length of the compound according to the present invention can be altered so as to control the characteristics.
Moreover, the polyorganosiloxane having the fluoroalkyl group with more fluorine atoms can be synthesized more easily than the compound having the group in the pendant site, and when the fluoroalkyl groups are introduced into both the pendant portion and the molecular chain end, the silicone rubber can possess improved oil resistance and solvent resistance.
Since the polyorganosiloxane of the present invention is able to have a very narrow molecular weight distribution (dispersity) of 1.1 to 1.2, i.e., a uniform molecular chain length, by using the lithium catalyst in an amount of 0.0005 to 0.5, preferably 0.0005 to 0.1 mole per mole of the silanol initiator, when the compound is introduced into a silicone rubber, the latter can take a more uniform structure than when a compound having a nonuniform molecular chain length is used. In addition, the synthetic process of the present invention by the utilization of the living polymerization does not form any cyclic compounds of dimethylsiloxane which cannot be removed by any means, whereas the equilibrating reaction using an acidic or basic catalyst cannot avoid the production of the cyclic compounds. Accordingly, the deterioration in physical properties and bleeding of the products and the scatter of product quality, which are attributable to these cyclic compounds, can be inhibited, so that the physical properties and the like can be improved.
When in place of a conventional terminal-modified polyorganosiloxane not having any reactive group and fluoroalkyl group in one molecule, the compound having the fluorine atom-containing substituent at an α-(α'- or α"-)position and the unsaturated double bond-containing substituent at a ω-(ω'- or ω"-)position of the present invention is introduced into a synthetic resin mainly comprising a polymer such as polymethyl (meth)acrylate, polyvinyl chloride or polyolefin, for example, polyethylene or polypropylene which can be obtained by the polymerization of the unsaturated double bond so as to improve the specific characteristics of the synthetic resin, the following effects can be obtained.
(1) Since the reactive group in the polyorganosiloxane of the present invention is chemically bonded to the synthetic resin, the deterioration in its characteristics with time can be inhibited.
(2) Since the fluoroalkyl group is present in one molecule, it is possible to provide the synthetic resin with various excellent specific functions of the fluorine atom-containing substituent, such as water repellency, stain resistance, release properties, non-adhesive properties, oil-repellent properties, low frictional properties and snow deposition resistance, which cannot be obtained from or is superior to the conventional polysiloxane terminated with trimethyl siloxy group, without impairing the characteristics of the polyorganosiloxane.
(3) It is possible to obtain a very narrow molecular weight distribution (dispersity) of 1.1 to 1.2, and therefore, when the polyorganosiloxane of the present invention having a uniform molecular chain length is introduced into the synthetic resin, the latter can take a more uniform structure than when a compound having a nonuniform molecular chain length is used. In addition, the synthetic process of the present invention by the utilization of living polymerization does not form any cyclic compounds of dimethylsiloxane which cannot be removed by any means, though a conventional equilibrating reaction by the use of an acidic or basic catalyst cannot avoid the production of the cyclic compound. Accordingly, the deterioration in physical properties and bleeding of the products and the scatter of products quality, which are attributable to these cyclic compounds, can be inhibited, so that the physical properties and the like can be improved.
(4) Also when the polyorganosiloxane of the present invention is used as a graft polymer so as to improve characteristics of the synthetic resin such as water repellency, stain resistance, release properties, non-adhesive properties, oil-repellent properties and low frictional properties, the synthetic resin can be provided with not only the function of the siloxane but also the specific function of the fluoroalkyl group. Furthermore, since the compound of the present invention is able to have the uniform molecular chain length, the uniform structure can be obtained, and in addition the molecular chain lengths of the siloxane portion and the fluoroalkyl group portion can be changed so as to regulate the characteristics. In consequence, the compound of the present invention can be applied to uses in which high performance is required, and in particular, it can be applied to the surface modification of the synthetic resin, to which uses the conventional dimethylsiloxane having no fluoroalkyl group cannot be applied.
(5) In the polyorganosiloxane of the present invention, three conditions can be optionally obtained which are the number of the 1 to 3 siloxane chains on the basis of the unsaturated double bond-containing substituent which is the group reactive with the synthetic resin, the number of the 1 to 3 siloxane chains on the basis of the fluorine atom-containing substituent, the length of the siloxane chain controlled in compliance with a purpose and the kind of fluorine atom-containing substituent at the terminal of the siloxane chain. Therefore, finely controlled characteristics can be given to the intended synthetic resin or silicone rubber in accordance with required functions.
EXAMPLES
Now, the present invention will be described in detail in reference to examples, but the scope of the present invention should not be limited to these examples.
EXAMPLE 1
Preparation of 1-(tridecafluoro-1,1,2,2-tetrahydrooctyl)-9-vinyldecamethylpentasiloxane:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 100.0 g (0.238 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 52.9 g (0.238 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.79 ml (1.5 mole/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 10 hours.
Next, 31.5 g (0.261 mole) of dimethylchlorosilane and 40.0 g (0.40 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred into a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 100 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of 1 H-NMR spectrum (nuclear magnetic resonance spectrum), IR spectrum (infrared absorption spectrum), GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR17##
1 H-NMR(CDCl 3 ): δppm
0.18 (Si(CH 3 ) 2 , s, 30H)
0.53-2.80 (SiCH 2 CH 2 , broad, 4H)
5.60-5.90 (Si--CH═CH 2 , m, 3H)
IR (KBr):
2970 cm -1 (C-H)
1610 cm -1 (Si--CH═CH 2 )
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 1.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--720
Weight average molecular weight (Mw)--865
Dispersity (Mw/Mn)--1.2
(molecular weight on calculated values was 728)
Viscosity (250° C.)--9.0 centipoise
The repeating unit i 1 can be obtained by the following formula on the basis of the data regarding the number average molecular weight of GPC:
i.sup.1 =(number average molecular weight--molecular weight of moiety A--molecular weight of moiety C)/ [molecular weight of one moiety B (=74.2)]
wherein the moieties A, B and C are as follows: ##STR18##
The number average molecular weight was 720, and therefore as a result of the calculation of this formula, i 1 =3.
This can be applied to the subsequent i 2 to i 17 in later examples.
However, it should be noted that the siloxane compounds are polymers having certain dispersions, and the thus obtained values of i's are only average values. Furthermore, since the data of the GPC number average molecular weights are approximate values, the calculated values of i's are also approximate values.
EXAMPLE 2
Preparation of a polydimethylsiloxane having a heptadecafluoro-1,1,2,2-tetrahydrodecyl group at the α-position and a vinyl group at the ω-position:
To a 2-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 250 ml of previously dried tetrahydrofuran, 12.4 g (0.0237 mole) of (heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethylsilanol and 244.0 g (1.10 moles) of hexamethylcyclotrisiloxane under N 2 gas, and 0.16 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 20 hours. Next, 3.0 g (0.0249 mole) of vinyldimethylchlorosilane and 4.0 g (0.040 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred into a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C-H)
1260 cm -1 (Si-CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 2.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--12130
Weight average molecular weight (Mw)--13530
Dispersity (Mw/Mn)--1.1
Viscosity (25° C.)--199 centipoise
EXAMPLE 3
Preparation of a polydimethylsiloxane having a pentafluorophenyl group at the α-position and a vinyl group at the ω-position:
To a 500-milliliter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 50 ml of previously dried tetrahydrofuran, 0.24 g (0.00099 mole) of (pentafluorophenyl)dimethylsilanol and 49.2 g (0.221 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.66 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C for 24 hours.
Next, 0.13 g (0.00108 mole) of vinyldimethylchlorosilane and 0.20 g (0.0020 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred into a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C-CH)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 3.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--1 43400
Weight average molecular weight (Mw)--52200
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--3680 centipoise
REFERENCE EXAMPLE 1
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a silanol group at the ω-position:
To a 5-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 1000 ml of previously dried tetrahydrofuran, 168.4 g (0.40 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 1032 g (4.64 moles) of hexamethylcyclotrisiloxane under N 2 gas, and 31.0 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 2.8 g (0.0464 mole of acetic acid was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR19##
IR (KBr):
3400-3200 cm -1 (Si--OH)
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 4.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3060
Weight average molecular weight (Mw)--3800
Dispersity (Mw/Mn)--1.2
Quantitative data of Si--OH group: OH (wt %)--0.55 (wt. %)
Molecular weight calculated on OH (wt %)--3090
Viscosity (25° C.)--42 centipoise
The repeating units i 2 to i 8 can be calculated in the same manner as in Example 1, but when analytical data of the terminal group (Si--OH) of the compound obtained in Reference Example 1 are utilized, more accurate values can be procured. That is,
i.sup.2 =(molecular weight calculated from the quantitative data for OH group-molecular weight of moiety G-molecular weight of moiety K)/[molecular weight of one moiety H (=74.2)]
wherein the moieties G, K and H are as follows: ##STR20##
As a result of the calculation in accordance with the above formula in which the molecular weight calculated from the quantitative data for the OH group was 3090, i 2 =35.
Each value of the repeating units i 3 to i 8 was i 2 +1, because compounds having the repeating units i 3 to i 8 were synthesized by using the compound in Reference Example 1 as the raw material.
EXAMPLE 4
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the ζ-position and a vinyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 127.0 g of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at an α-position and a dimethylsilanol group at a ω-position obtained in Reference Example 1, 7.0 g (0.0692 mole) of triethylamine, and 5.46 ml (0.0452 mole) of vinyldimethylchlorosilane was then added dropwise thereto at room temperature. After completion of the addition, the solution was further stirred for 1 hour to perform reaction. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting salt therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained siloxane compound, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR21##
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 5.
Molecular weight determined by the GPC technique with polystylene standards (toluene):
Number average molecular weight (Mn)--3110
Weight average molecular weight (Mw)--3800
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--35 centipoise
As a result of calculation in accordance with eh previously mentioned formula, i 3 =36.
EXAMPLE 5
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α"-positions and a vinyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 127.0 g of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at an α-position and a dimethylsilanol group at a ω-position obtained in Reference Example 1 and 7.0 g (0.0692 mole) of triethylamine, and 3.17 g (0.0226 mole) of methylvinylchlorosilane was then added dropwise thereto at room temperature. After completion of the addition, the solution was further stirred for 1 hour to perform reaction. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting salt therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR22##
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 6.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--5790
Weight average molecular weight (Mw)--6830
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--1 68 centipoise
As a result of calculation in accordance with the previously mentioned formula, i 4 =i 5 =36.
EXAMPLE 6
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α',α"-positions and a vinyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer, and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 127.0 g of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at an α-position and a dimethylsilanol group at a ω-position obtained in Reference Example 1 and 7.0 g (0.0692 mole) of triethylamine, and 2.42 g (0.0151 mole) of vinyltrichlorosilane was then added dropwise thereto at room temperature. After completion of the addition, the solution was further stirred for 1 hour to perform reaction,. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting salt therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR23##
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 7.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--8010
Weight average molecular weight (Mw)--9590
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--93 centipoise
As a result of calculation in accordance with the previously mentioned formula, i 6 =i 7 =i 8 =36.
EXAMPLE 7
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α',α"-positions and an allyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 2.65 g (0.0151 mole) of allyltrichlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR24##
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 8.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight--(Mn) 7830
Weight average molecular weight (Mw)--9390
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--91 centipoise
EXAMPLE 8
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a 5-hexenyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 8.0 g (0.0452 mole) of 5-hexenyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate. Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 9.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3290
Weight average molecular weight (Mw)--4000
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--34 centipoise
EXAMPLE 9
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α',α"-positions and a 5-hexenyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 3.29 g (0.0151 mole) of 5-hexenyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 10.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--7820
Weight average molecular weight (Mw)--9490
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.) 89 centipoise
EXAMPLE 10
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a 7-octenyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 9.25 g (0.0452 mole) of 7-octenyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 11.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3300
Weight average molecular weight (Mw)--4000
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--35 centipoise
EXAMPLE 11
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α',α"-positions and a 7-octenyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 3.71 g (0.0151 mole) of 7-octenylmethyltrichlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 12.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--7880
Weight average molecular weight (Mw)--9650
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--89 centipoise
EXAMPLE 12
Preparation of a polydimethylsiloxane having a 3,3,3-trifluoropropyl group at the α-position and a 13-tetradecenyl group at the ω-position:
To a 100-milliliter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 10 ml of previously dried tetrahydrofuran, 0.71 g (0.00411 mole) of (3,3,3-trifluoropropyl)dimethylsilanol and 10.60 g (0.0476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 2.7 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 1.31 g (0.00452 mole) of 13-tetradecenyldimethylchlorosilane and 0.70 g (0.0069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm 1 (Si--O)
An IR chart is shown in FIG. 13.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3430
Weight average molecular weight (Mw)--4090
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--35 centipoise
EXAMPLE 13
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a methylphenylvinylsilyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 8.26 g (0.0452 mole) of methylphenylvinylchlorosilane and 0.70 g (0.0069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
730 cm -1 ##STR25##
An IR chart is shown in FIG. 14.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3100
Weight average molecular weight (Mw)--3820
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--38 centipoise
EXAMPLE 14
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a diphenylvinylsilyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 11.1 g (0.0452 mole) of diphenylvinylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed 5 with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained dimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
730 cm -1 ##STR26##
An IR chart is shown in FIG. 15.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3520
Weight average molecular weight (Mw)--4280
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--45 centipoise
EXAMPLE 15
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α,α"-positions and an ethylvinylsilyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 3.50 g (0.0226 mole) of ethylvinyldichlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR27##
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 16.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--6420
Weight average molecular weight (Mw)--7280
Dispersity (Mw/Mn)--1.1
Viscosity (25° C.)--75 centipoise
As a result of calculation in accordance with the previously mentioned formula, wherein the number average molecular weight is 6,420, i 9 =i 10 =37.
EXAMPLE 16
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a methacryloxypropyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 9.98 g (0.0452 mole) of 3-methacyloxypropyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1720 cm -1 (C═O)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 17.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3370
Weight average molecular weight (Mw) 4050
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--37 centipoise
EXAMPLE 17
Preparation of a polydimethylsiloxane having a heptadecafluoro-1,1,2,2-tetrahydrodecyl group at the α-position and a methacryloxypropyl group at the ω-position:
To a 2-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 300 ml of previously dried tetrahydrofuran, 21.5 g (0.0411 mole) of (heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethylsilanol and 300.5 g (1.35 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 20 hours.
Next, 9.98 g (0.0452 mole) of 3-methacyloxypropyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1720 cm -1 (C═O)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 18.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--9810
Weight average molecular weight (Mw)--10850
Dispersity (Mw/Mn)--1.1
Viscosity (25° C.) 127 centipoise
EXAMPLE 18
Preparation of a polydimethylsiloxane having a pentafluorophenyl group at the α-position and a methacryloxypropyl group at the ω-position:
To a 2-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 300 ml of previously dried tetrahydrofuran, 9.96 g (0.0411 mole) of (pentafluorophenyl)dimethylsilanol and 311.6 g (1.40 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 20 hours.
Next, 9.98 g (0.0452 mole) of 3-methacyloxypropyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1720 cm -1 (C═O)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 19.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--8730
Weight average molecular weight (Mw)--9960
Dispersity (Mw/Mn)--1.1
Viscosity (25° C.) 98 centipoise
EXAMPLE 19
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and an ethenylphenyl group at the ω-position:
To a 1-liter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 100 ml of previously dried tetrahydrofuran, 17.3 g (0.0411 mole) of 5 (tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilanol and 106.0 g (0.476 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 0.27 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 8.89 g (0.0452 mole) of p-ethenylphenyldimethylchlorosilane and 7.0 g (0.069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 20.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3360
Weight average molecular weight (Mw)--4150
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.) 38 centipoise
EXAMPLE 20
Preparation of a polydimethylsiloxane having a
3-(heptafluoroisopropoxy)propyl group at the α-position and a vinyl group at the ω,ω'-positions:
To a 100-milliliter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 10 ml of previously dried tetrahydrofuran, 0.42 g (0.00411 mole) of vinyldimethylsilanol and 0.92 g (0.0415 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 2.7 ml (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 5 hours.
Next, 0.77 g (0.00226 mole) of 3-(heptafluoroisopropoxy)propylmethyldichlorosilane and 0.70 g (0.0069 mole) of triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum and GPC (gel permeation chromatography) were as follows:
IR (KBr):
2970 cm -1 (C--H)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 21.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--520
Weight average molecular weight (Mw)--630
Dispersity (Mw/Mn)--1.2
EXAMPLE 21
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a vinyl group at the ω,ω',ω"-positions:
To a 500-milliliter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 40 ml of previously dried tetrahydrofuran, 0.42 g (0.00411 mole) of vinyldimethylsilanol and 39.0 g (0.175 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 27 μl (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 20 hours.
Next, 0.73 g (0.00151 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane and 0.70 g (0.0069 mole) triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate.
Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of 100° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR28##
IR (KBr):
2970 cm -1 (C--H)
1610 cm -1 (Si--CH═CH 2 )
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 22.
Molecular weight determined by the GPC technique with polystylene standards (toluene):
Number average molecular weight (Mn)--34120
Weight average molecular weight (Mw)--38770
Dispersity (Mw/Mn)--1.1
Viscosity (25° C.)--686 centipoise
The repeating units i 12 , i 13 and i 14 can be calculated in the same manner as in Example 1. The compound prepared in this example can be calculated as follows:
i 12 =(number average molecular weight--molecular weight of moiety D--molecular weight of moiety F)/ [molecular weight of three moieties E(=74.2×3)]
wherein the moieties D, E and F are as follows: ##STR29##
In this case, the molecular weight of the moiety F is the total weight of the three siloxane terminal substituents, and that of the moiety E is also the total of the three groups. Each value of i 13 and i 14 is the same as an average value of i 12 obtained by the calculation.
As a result of the calculation in accordance with the above formula in which the average molecular weight was 34, 120, i 12 =i 13 =i 14 =150.
EXAMPLE 22
Preparation of a polydimethylsiloxane having a tridecafluoro-1,1,2,2-tetrahydrooctyl group at the α-position and a 3-methacryloxypropyl group at the ω,ω',ω"-positions:
To a 500-milliliter three-necked round bottom flask equipped with a stirrer and a cooling device were fed 10 ml of previously dried tetrahydrofuran, 0.83 g (0.00411 mole) of 3-methacryloxypropyldimethylsilanol and 3.49 g (0.0157 mole) of hexamethylcyclotrisiloxane under N 2 gas, and 27 μl (1.5 moles/l) of a butyl lithium hexane solution was then added thereto and polymerization was performed at 20° C. for 15 hours.
Next, 0.727 g (0.00151 mole) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane and 0.70 g (0.0069 mole triethylamine was further added thereto, followed by stirring for 1 hour in order to bring the polymerization to an end. The thus synthesized material was then transferred to a separating funnel, then washed with water to remove the resulting lithium chloride therefrom, and dried with anhydrous sodium sulfate. Afterward, low-boiling substances in the resulting reaction product were distilled off under conditions of ° C. and 10 mmHg over 2 hours, thereby obtaining a desired polydimethylsiloxane in a substantially quantitative yield. With regard to the thus obtained polydimethylsiloxane, analytical results of IR spectrum, GPC (gel permeation chromatography) and viscosity were as follows, and it was confirmed that the obtained polydimethylsiloxane had the following structure: ##STR30##
IR (KBr):
2970 cm -1 (C--H)
1720 cm -1 (C═O)
1260 cm -1 (Si--CH 3 )
1250-1150 cm -1 (CF 2 , CF 3 )
1120-1050 cm -1 (Si--O)
An IR chart is shown in FIG. 23.
Molecular weight determined by the GPC technique with polystyrene standards (toluene):
Number average molecular weight (Mn)--3510
Weight average molecular weight (Mw)--4300
Dispersity (Mw/Mn)--1.2
Viscosity (25° C.)--41 centipoise
As a result of calculation in accordance with the previously mentioned formula, wherein the number average molecular weight was 3,510, i 15 =i 16 =i 17 =11. | A novel polyorganosiloxane is provided which has a fluorine atom-containing substituent at one terminal of its molecular chain and an unsaturated double bond-containing substituent at the other terminal thereof. The polyorgansiloxane of the present invention is represented by the general formula (I) ##STR1## wherein j is an integer of 1 to 2000, and R 1 is an unsaturated double bond-containing group, each of R 2 and R 3 is an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, straight-chain or branched alkenyl group having 3 to 20 carbon atoms, or a siloxane chain which is similar to ##STR2## and R 4 is a fluorine atom-containing substituent, ##STR3## wherein R 10 is similar to R 4 and is the fruorine atom-containing substituent, R 11 is an alkyl group having 1 to 4 carbon atoms or phenyl group, and the oxygen atoms sited on the right side of the above formulae are combined with a siloxane chain having the unsaturated double bond-containing substituent at the terminal thereof which is similar to ##STR4## | 2 |
FIELD OF THE INVENTION
The field of the present invention relates to a power distribution, for example for use in an array of active electronic circuits within or adjacent to an antenna in a mobile communications base-station.
BACKGROUND OF THE INVENTION
Currently power distribution within an array of active electronic circuits located within or adjacent to an antenna is achieved using a “star” topology, i.e. a pair of wires (positive and ground) is connected from the power supply to each one of the active electronic circuits individually. For 16 antenna elements this results in 16 pairs of (relatively) high-current wires being required. These wires are also often flexible and therefore require insulating throughout their length which adds to the weight and cost of the wires.
The European patent application 0 323 169 describes a power distribution system for a phased array radar. The power distribution system includes a large number of small capacitors, at least one per module, a lesser number of large capacitors, at least one at each end of each row, and bus bars dimensioned for a very small radio frequency (RF) impedance for supplying peak power in a timely manner to the modules from the large capacitors. The European patent application 0 323 169 A2 describes a hierarchy of the power distribution system and an interaction between the various components of the power distribution system. The bus bar described in EP 0 323 169 A2 is a multi-layer laminate, i.e. a printed circuit board (PCB). The multi-layer laminates of the required size are expensive and have a high weight.
SUMMARY OF THE INVENTION
It would be desirable to have a power distribution for use in an array of active electronic circuits in a mobile communications base-station that is relatively inexpensive and relatively light in weight. It would further be desirable that the power distribution has a good efficiency and does not generate excessive losses. These concerns and/or possible other concerns are addressed by a power distribution for an array of active electronic circuits located within or adjacent to an antenna in a mobile communications base-station that comprises a first conductor connectable to a first terminal of a power supply unit and a second conductor connectable to a second terminal of the power supply unit. The first conductor and the second conductor are at least partly bare and rigid and are routed to the active electronic circuits in a manner separate from each other.
In the power distribution no insulation is needed for at least portions of at least one of the first conductor and the second conductor. A risk of short circuits is avoided or at least reduced by separate routing the first conductor and the second conductor in a manner separate from each other, and by the fact that at least portions of the first conductor and/or the second conductor are rigid. The term “separate routing” means that the first conductor and the second conductor each have a defined path between the power supply unit and the array of active electronic circuits (or within the array of active electronic circuits for a sub-distribution of power to the individual active electronic circuits) that neither the first conductor nor the second conductor spatially coincide with each other, even partly. Separate routing may be achieved by measures that prevent a direct contact between a bare portion of the first conductor and a bare portion of the second conductor.
The first conductor may be routed along a first side of the active electronic circuits and the second conductor may be routed along a second side of the active electronic circuits. The routing of the first and second conductors along different sides of the active electronic circuits may allow more evenly distributed exploitation of the available space.
The array may comprise a plurality of interstices between the active electronic circuits and the first conductor may be routed along a first one of the plurality of interstices and the second conductor may be routed along a second one of the plurality of interstices. This relation between the first conductor and a first one of the plurality of interstices, as well as a relation between the second conductor and a second one of the plurality of interstices, allows for a balanced distribution of the first conductor and the second conductor. At the same time, the first conductor and the second conductor may be routed in proximity to each of the active electronic circuits so that between the first conductor and the second conductor and the active electronic circuits only a short distance, if any, needs to be bridged in order to assure power distribution to the active electronic circuits. The term “interstices” also is intended to encompass the edges of the array.
The first conductor may be routed along alternate ones of the plurality of interstices and the second conductor may be routed along alternate ones of the plurality of interstices separate from the alternate ones of the plurality of interstices along which the first conductor is routed. In this manner the first conductor is, for example, on the left side of a specific set of active electronic circuits, while the second conductor is located on the right side of this specific set of active electronic circuits.
At least a portion of the first conductor may be routed along at least a portion of an edge of the array and at least a portion of the second conductor may be routed in between the active electronic circuits of the array (or vice versa).
At least one of the first conductor and the second conductor may comprise a trunk portion and a plurality of branch portions that connect the trunk portion with the active electronic circuits. The trunk portion extends from the power supply unit to a point that is reasonably close to one or more of the active electronic circuits. The remaining distance between this point and the active electronic circuits may then be covered by one branch portion out of the plurality of branch portions.
The power distribution may further comprise fixation elements for fixing at least one of the first conductor and the second conductor to a chassis of the array of active electronic circuits.
The fixation elements may be insulating spacers between the chassis and the first conductor. In the alternative or in addition the insulating spacers may be between the chassis and the second conductor. Individual ones of the insulating spacers may be present between the chassis and the first conductor, as well as between the chassis and the second conductor.
The chassis may comprise an insulating material. The first conductor and the second conductor may be placed directly on the surface of the insulating material of the chassis and the fixation elements may be screws, hooks, clamps, snap taps or another suitable element.
At least a part of the second conductor may be formed by a chassis of the array of active electronic circuits. The chassis or a part of the chassis may assume the role of the second conductor (or the first conductor) if the chassis or at least a part of the chassis if made from an electricity conducting material. The use of the chassis as one of the conductors can save weight and cost, since it effectively removes the need for one of the conductors throughout the system (together with the insulation of the removed conductor, in the case of a flexible conductor).
At least one of the first conductor and the second conductor may be part of a mounting structure of each of the active electronic circuits. Using the first conductor and/or the second conductor as part of the mounting structure may save further weight, as some of the existing mechanical structures could be reduced in thickness, since the demands placed on the rigidity of the mechanical structures would be reduced.
At least one of the first conductor and the second conductor may be tapered. Tapering the first conductor and/or the second conductor may provide a further weight and material cost saving. Tapering of one or both of the conductors takes advantage of the reduced current conduction requirements placed upon the conductors as the number of transceivers which the conductors need to supply reduces with distance from the power supply unit. This approach therefore saves weight and cost without significantly increasing the losses in the conductors, with its consequent impact upon system efficiency.
The power distribution may further comprise flexible power connections between individual ones of the active electronic circuits and at least one of the first conductor and the second conductor. Typically, the flexible power connection only needs to bridge a short distance between the first conductor and/or the second conductor and one of the active electronic circuits. The flexible power connections may be easy to install during the manufacture of the array of active electronic circuits. Furthermore, the first conductor and the second conductor may be routed in such a manner that the distance between the first conductor and/or the second conductor and each of the arrays of active electronic circuits is substantially equal. In this case, the flexible power connections may have the same length which reduces the number of different parts required to be designed and manufactured for the array of active electronic circuits.
The power distribution may further comprise connectors adapted to detachably connect the flexible power connections with at least one of the first conductor and the second conductor. The connectors allow a temporary removal of the flexible power connections from the first/second conductor, for example during maintenance or repair of the array.
The power distribution may further comprise at least one additional conductor for providing at least one further electrical potential to the active electronic circuits, wherein the at least one additional conductor is connectable to at least one additional terminal of the power supply unit. The additional conductor allows the distribution of an additional electrical potential and thus of at least one additional electrical voltage.
The power distribution may be adapted for providing a direct current (DC) to the array of active electronic circuits. A centralised generation and conditioning of DC electrical power is usually more efficient, in both power usage and cost, than a localised generation within the active electronic circuits.
The power supply unit may be a direct current power supply unit and may be a part of the power distribution.
The power distribution may comprise a back-up power supply unit for providing the current to the array of active electronic circuits in case of a failure of the power supply unit. The back-up power supply unit adds redundancy to the power distribution so that the power distribution may usually continue to operate when the main power supply unit has failed. The failure of the main power supply unit may be reported to a failure management system of the base-station so that it may be serviced or replaced soon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art power distribution.
FIG. 2 shows a first example of a power distribution.
FIG. 3 shows a second example of a power distribution.
FIG. 4 shows a third example of the power distribution.
FIG. 5 shows a fourth example of the power distribution.
FIG. 6 shows a portion of an array of active electronic circuits in a perspective view to illustrate a possible configuration of the power distribution.
FIG. 7 shows a larger array of transceivers and a conceivable example of the power distribution.
FIG. 8 shows a fifth example of the power distribution.
FIG. 9 shows a sixth example of the power distribution.
FIG. 10 shows examples for the connection between the bus bars and the flexible connections.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described on the basis of the drawings. It will be understood that the embodiments and aspects of the invention described herein are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will also be understood that a feature of one aspect can be combined with the features of another aspect or other aspects.
FIG. 1 shows an existing method of distributing power within an adaptive antenna or antenna-embedded radio system. FIG. 1 shows in a schematic manner a 2-by-8 array of 16 antenna embedded radios TRX 1 -TRX 16 . Each one of the active electronic circuits or transceivers TRX 1 -TRX 16 is directly connected to a power supply unit PSU, typically via a pair of multi-strand, flexible cables 12 —one of the multi-strand, flexible cables 12 is for the positive connection and an other one of the multi-strand, flexible cables 12 is for the negative or ground connection. Each one of the multi-strand, flexible cables 12 is individually insulated, occupies a significant amount of space and has a certain weight. Furthermore, a compromise needs to be struck between the weight and cost of the multi-strand, flexible cables 12 versus their loss.
FIG. 2 shows one example for a bus-bar concept of power distribution. In this case, a single pair of bus-bars 21 is located centrally within the antenna, with short supply connections 22 taken from these bus-bars to the individual transceiver/antenna elements. Note that it is likely that in a practical implementation, the bus-bars 21 themselves would be rigid, for example being made from solid copper bars. The individual power connections 22 to the transceivers would be fabricated from the multi-strand, flexible wires, as will be explained in connection with FIG. 6 . In the alternative, the connections 22 to the individual transceivers could be rigid (or semi-rigid), with little or no insulation being required.
FIG. 3 shows a second example for the bus-bar concept of power distribution. In this case, the bus-bars 31 and 33 are split and located around the outside of the antenna structure. This approach would allow the (rigid) bus-bars 31 and 33 to be a part of the mechanical structure of the antenna itself, for example by providing the mechanical mounting facilities for the antenna elements or transceiver modules TRX 1 -TRX 16 . This would, in turn, save further weight, as some of the existing mechanical structures could be reduced in thickness, since the demands placed upon the rigidity of the mechanical structures would be reduced. The place between the two rows of transceivers TRX 1 -TRX 16 may be used for other types of connections, such as data busses to and from a central hub (not shown) serving the array of transceivers. Supply connections 32 connect the bus bars 31 and 33 with the transceivers TRX 1 -TRX 16 . For clarity reasons, only the two upper supply connections for transceivers TRX 1 and TRX 2 are referenced with the reference sign 32 .
FIG. 4 shows a combination of the two examples shown in FIGS. 2 and 3 . In the case of FIG. 4 the positive (“+”) bus-bar 45 and the negative (“−”) bus bars 41 and 43 are shown separately. The positive bus bar 45 is placed in the centre of the antenna structure of the array and the negative bus bars 41 and 43 are placed around the outside of the antenna structure or the array. Supply connections 42 connect the negative bus bars 41 and 43 with the transceivers TRX 1 -TRX 16 . Supply connections 46 connect the positive bus bar 45 with the transceivers TRX 1 -TRX 16 . This example extends the mechanical mounting options and also insures that the positive conductor 45 and negative conductors 41 and 43 are placed far apart, thereby minimizing the chances of accidental short circuits occurring between the positive conductor 45 and the negative conductors 41 and 43 . Note that the position of the positive bus bar 45 and the negative bus bars 41 and 43 could be swapped in this example with no loss of functionality.
Note also that a variant to the example shown in FIG. 2 would be to place the positive bus bar 45 either on the far left-hand side or the far right-hand side of the transceiver/antenna elements (rather than in the centre). This would slightly lengthen some of the individual transceiver power connections 42 and 46 , however it may be mechanically or logistically preferable in some circumstances. Likewise, it is possible to split the location of the positive bus bar 45 and the negative (or ground) bus bars 41 and 43 , with one of the bus bars being located on the far left of the antenna-elements and the other of the bus bars on the far right.
FIG. 5 shows a further variant of the example shown in FIG. 2 , in which the thickness of the bus bar 51 is reduced or stepwise tapered, as the number of transceivers the bus bar is required to feed, reduces with the distance from the power supply unit PSU. The transceivers TRX 1 -TRX 16 are connected to the bus bar 51 by means the of supply connections 52 . This reduction or tapering of the bus bar provides a further weight and material cost saving. Additional fabrication costs may arise for the reduced or tapered bus bar 51 as shown in FIG. 5 . Note that only four thicknesses are shown in FIG. 5 , for clarity, however a greater number (e.g. 8) or a lesser number (e.g 2) could be chosen, depending upon the economic trade-off outlined above. These numbers are based upon the 16-element array shown in the examples in this disclosure. The numbers could change for different sizes of the arrays. It is also possible to apply this bus-bar thickness “reduction” or “tapering” concept to the other examples discussed above.
FIG. 6 shows a portion of the transceiver array in a perspective view. The array is mounted on a chassis 610 . The positive bus bar 622 and the negative bus bar 624 extend in a parallel, yet separate manner along a row of transceivers comprising the transceivers TRX 5 , TRX 7 and TRX 9 . Flexible connection 635 , 637 and 639 connect the positive bus bar 622 and the negative bus bar 624 with each of the transceivers TRX 5 , TRX 7 and TRX 9 , respectively. At an end that for connection with the positive bus bar 622 and the negative bus bar 624 the flexible power connections 635 , 637 each comprise a plug that is adapted to fit into a matching connector or socket 645 , 647 and 649 attached to the bus bars 622 , 624 .
FIG. 10 shows another option for connecting the flexible connections 1035 with the positive bus bar 21 p and the negative bus bar 21 n . The bus bars 21 p , 21 n contain holes 1045 which have been tapped to accept a screw thread and the flexible connections 1035 could be terminated in crimped or soldered ring connectors 1067 (upper example in FIG. 10 ) or split-spade/fork connectors 1065 (lower example in FIG. 10 ). These ring connectors 1067 or split-spade/fork connectors 1037 could then be attached to the bus bars 21 p , 21 n by means of bolts 1055 passing through the ring or split-spade part of the terminations and screwed into the threaded holes 1045 in the bus-bars 21 p , 21 n.
FIG. 7 shows a larger array of transceivers TRX 1 , 1 -TRXn, 6 and a conceivable example of the power distribution. Between two adjacent rows of the array one or more interstices belonging to a plurality of interstices can be found. The negative bus bar 71 extends along those interstices having an even number, e.g. 0, 2, 4 . . . . The positive bus bar 75 extends along those interstices having odd numbers, e.g. 1, 3, 5 . . . . Each row of the transceivers TRX 1 , 1 -TRXn, 6 has the negative conductor 71 on the left side and the positive conductor 75 on the right side, or vice versa. The distance between the bus bars 71 and 75 and the transceivers TRX 1 , 1 -TRXn, 6 is small so that individual branch portions for the transceivers may be short.
FIG. 8 shows a fifth example of the power distribution system. The power distribution according to the fifth example is derived from the third example of the power distribution depicted in FIG. 4 . The power distribution according to the fifth example comprises two positive conductors 45 and 85 . The first positive conductor 45 distributes a first electrical potential V 1 from the power supply unit PSU to the transceivers TRX 1 -TRX 16 . The second positive conductor 85 distributes a second electrical potential V 2 from the power supply unit PSU to the transceivers TRX 1 -TRX 16 . An electrical ground potential GND is distributed by means of the negative conductor. As in the third example of the power distribution shown in FIG. 4 , the supply connections 46 connect the first positive bus bar 45 with the transceivers TRX 1 -TRX 16 . Likewise, supply connections 86 connect the second positive bus bar 85 with the TRX 1 -TRX 16 .
FIG. 9 shows a sixth example of the power distribution which is a variant of the first example of the power distribution in an array of active electronic circuits. Besides being connected to a main power supply unit PSU 1 the power distribution is also connected to a back-up power supply unit PSU 2 . The back-up power supply unit PSU 2 is activated when the main power supply unit PSU 1 fails. The fact that the main power supply unit PSU 1 has failed may be reported to a failure management system of the array of active electronic circuits or of the base transceiver station. Solitary power supply units as in the examples shown in FIGS. 2 to 8 represent a single point of failure and are therefore critical in terms of reliability. The back-up power supply unit PSU 2 adds redundancy to the power distribution system, making the power distribution of the array of active electronic circuits more reliable.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that various changes in form and detail can be made therein without departing from the scope of the invention. The present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | A power distribution for an array of active electronic circuits in an antenna of a mobile communications base-station is disclosed. The power distribution comprises a first conductor connectable to a first terminal of a power supply unit, and a second conductor connectable to a second terminal of the power supply unit. The first conductor and the second conductor are at least partly bare and rigid, and are routed to the antenna-embedded radios in a manner separate from each other. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the field of insertion of intra-ocular lenses, and provides an improved device for inserting an intra-ocular lens into the eye.
[0002] The original intra-ocular lens (IOL) introduced in 1948 was made of poly(methyl methacrylate), with polypropylene haptics. It was rigid and inflexible and its insertion required a 7 to 9 mm incision in the eye and a stitch to close the wound, with attendant discomfort and the inconvenience of later stitch removal.
[0003] With the advent of flexible IOLs made of silicone or acrylate elastomers, which could be folded and inserted into the eye through an incision that might be as small as 2.8 mm or less, no stitch was necessary and the whole procedure was simplified and abbreviated.
[0004] The use of flexible IOLs created a need for a device that could guide the lens into the smaller opening in the eye. One example of a device for insertion of an IOL is given in U.S. Pat. No. 4,681,102. Other devices for accomplishing the insertion are described in U.S. Pat. Nos. 5,716,364, 5,803,925, 5,947,976, and 5,976,150. The disclosures of all of the above-cited patents are incorporated by reference herein.
[0005] The basic principle embodied in the design of any of the devices shown in the above-cited patents is to provide a lubricious pathway for a folded IOL to be pushed without damage into the corneal chamber (often described as “the bag”) from which the eye's natural lens has been removed, where the IOL can unfold spontaneously.
[0006] Clearly, many variations are possible in the mechanical design of the apparatus that could carry out the insertion of an IOL satisfactorily, embodying the above-cited principle.
[0007] The insertion device, usually formed from plastic and often from polypropylene, comprises a channel that at the proximal end is open, and communicates with a tubular channel that extends to a distal open end. In the operation of some insertion devices, the flexible IOL is placed in the open end of the channel in a folded configuration. In other insertion devices, the IOL becomes folded as a result of design features in the channel that promote folding. The distal end of the device is positioned at the incision in the eye and the IOL pushed through the channel and into the eye. In the presentation that follows, the untreated plastic device will be referred to as the “cartridge”.
[0008] The requirement that the IOL be moved through the device without damage is critically important, and a corollary requirement is that the passageway be adequately lubricated to reduce friction to a harmless level. The friction to be overcome is jointly characteristic of the IOL and haptic surfaces on the one hand, and the surface of the inner wall of the channel through which the lens is moved on the other hand; i.e., friction cannot be defined as a property of a single surface, but of both surfaces, either or both of which may be moving to generate the friction.
[0009] The problem of lubricating the insertion channel has been addressed, to some extent, in the prior art, including some of the patents cited above. For example, U.S. Pat. No. 4,681,102 briefly describes treating the lumen through which the IOL passes with a product known by the trademark Healon. Healon is a solution of sodium hyaluronate in water. A problem with the latter approach is that the Healon can be harmful if introduced into the eye, and not completely removed after the IOL is inserted.
[0010] U.S. Pat. No. 5,716,364 also is concerned with lubricating the interface between IOL and the cartridge wall, so as to reduce friction in the movement of the folded IOL. The patent describes the use of lubricants that are not covalently bonded to the surface of the inserter, such as glyceryl monostearate or polyvinylpyrrolidone (PVP). The lubricant is said to be incorporated uniformly throughout the polypropylene, presumably by mixing and compounding in an extruder or milling on plastics processing rolls, and because the lubricant and polypropylene are mutually incompatible, the lubricant blooms to the surface of the cartridge, where it acts to facilitate the passage of the IOL. For the very reason that the lubricant is not bonded chemically to the polypropylene and is therefore mobile and capable of moving to the surface of the cartridge wall, it can be carried along with the IOL and some of it also inserted into the eye. Either glyceryl monostearate or PVP is foreign contamination of the viscous fluid that fills the eye, and whether it will cause long-term problems can only be determined by years of clinical experience.
[0011] The same U.S. Pat. No. 5,716,364 also describes a covalently bonded lubricity enhancing component, but no teaching is made in this patent as to how glyceryl monostearate or PVP might be covalently bound to polypropylene.
[0012] In U.S. Pat. No. 5,803,925, the subject is an IOL inserter with a covalently bound lubricant of the type represented by the formula A-PEG, where A is a reactive group capable of bonding chemically to the surface of the cartridge, and PEG is polyethylene glycol or other hydrophilic (or oleophilic) polymer. In the operation of the inserter, the clean cartridge is soaked for about three hours in a solution of the A-PEG and is then subjected to UV irradiation to cause photolysis of the polypropylene and bonding of the A-PEG.
[0013] The covalently bonded and immobile “lubricant” does not lubricate adequately to facilitate the passage of the IOL through the pathway of the device. The patent states that a balanced salt solution of sodium hyaluronate (BSS) must be used along with the treated inserter in order to achieve sufficiently low friction for the IOL to pass, with the normal application of force. The patent reports the finding that neither the cartridge with bonded A-PEG but without BSS, nor the untreated cartridge with BSS alone, is effective in passing the folded IOL
[0014] The present invention comprises an IOL insertion device having a continuous, bilaminar, lubricious coating which is permanently bound to at least a portion of the inner surface of the channel through which an IOL passes. The coatings used with the insertion device of the present invention have been found to produce results that are superior to those of any of the known IOL insertion devices of the prior art.
SUMMARY OF THE INVENTION
[0015] The present invention comprises an insertion device for an intra-ocular lens (IOL), the insertion device defining a channel through which the IOL is advanced while inserting it into an eye. At least the interior surface of the insertion device, i.e. the surface which contacts the IOL during the insertion process, has a bilaminar coating. The bilaminar coating includes a highly lubricious top coat which is chemically grafted to a base coat, the base coat firmly adhering to the surface of the insertion device. The base coat comprises a polymer which includes functional groups capable of participating in reactions for grafting the base coat to the top coat.
[0016] The top coat is preferably a solution of a polymer selected from the group consisting of a polysaccharide, a cellulose derivative, polyacrylic acid, and polyethylene glycol. The preferred top coat is an aqueous solution of hyaluronan. The top coat may also include surfactants, crosslinking agents, plasticizers, solvents, salts, and/or leveling agents.
[0017] The base coat comprises a polymer or copolymer capable of providing adhesion to the substrate surface. Preferably the base coat is selected from the group consisting of acrylic polymers and acrylic copolymers.
[0018] The insertion device is preferably made of a moldable material, such as plastic. More particularly, the moldable material can be selected from the group consisting of polypropylene, acrylic polymers, acrylic copolymers, nylon, polyester, cellulose acetate, and acetate/butyrate.
[0019] When the channel is wet with water, the insertion device described above provides an extremely lubricious interface between the IOL and the channel. The coating applied to the insertion device is permanent, and does not become dislodged as the IOL is advanced into the eye.
[0020] The invention also comprises a method of enhancing the lubricity of an insertion device for an IOL, the method including applying a bilaminar coating of the kind described above, to at least a portion of the interior surface of the insertion device.
[0021] The present invention therefore has the primary object of providing an insertion device for an intra-ocular lens (IOL).
[0022] The invention has the further object of providing an insertion device for an IOL which substantially reduces the friction between the IOL and the insertion device, as the IOL is advanced into an eye.
[0023] The invention has the further object of providing an insertion device having a permanent coating that becomes exceedingly lubricious when wet with water.
[0024] The invention has the further object of preventing unwanted substances from entering the eye during the process of insertion of an IOL.
[0025] The invention has the further object of enhancing the safety of an IOL insertion procedure.
[0026] The invention has the further object of providing a method of enhancing the lubricity of an insertion device for an IOL.
[0027] The reader skilled in the art will recognize other objects and advantages of the present invention, from a reading of the following detailed description of the invention, and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention is based on the discovery that a continuous, lubricious coating, permanently bound to an IOL insertion device, is more effective in facilitating passage of the IOL than a covalently bonded lubricant, does not contaminate the eye with foreign matter, and is superior in having other unexpected advantages, as will be described. Coatings made according to the present invention have demonstrated excellent performance in practical experience of providing lubricity for vascular catheters and guide wires, with unexcelled biocompatibility and freedom from undesirable side effects. Their adaptability to an IOL insertion device comprising a polypropylene cartridge, and the consequent virtues in such an application, were unforeseen and not predictable.
[0029] The coatings used in the present invention are bilaminar, hydrophilic, lubricious coatings formed on substrates which are typically plastic. Such coatings are described in U.S. Pat. Nos. 4,801,475, 5,023,114, and 5,037,677, the disclosures of which are hereby incorporated by reference. In general, these patents disclose bilaminar coatings comprising a primary or base coat that adheres tightly to a plastic substrate, and a top coat which is hydrophilic, lubricious and durable. In one preferred embodiment, the top coat is a polysaccharide such as hyaluronan. The primary coat and the top coat are grafted together with covalent bonds, and retain their individual identities even after grafting. The base coat is sometimes called a “tie-coat” because it ties the top coat to the substrate.
[0030] In the coatings described in the above-cited patents, the primary coat and the top coat are grafted together with covalent bonds, and retain their individual identities even after grafting. The above-cited patents teach that these bilaminar coatings can be used on catheters, guide wires, prosthetic devices, or intra-ocular lenses. However, none of these patents discloses or suggests the use of such coatings on an interior surface of a channel used for insertion of an IOL.
[0031] As in the above-cited patents, the coatings used in the present invention are bilaminar, comprising a base coat that is 1) highly adherent to polypropylene and 2) functional in the sense of being able to participate in reactions with agents for grafting the base coat to a suitable lubricious top coat. Materials and conditions of application are specifically chosen and designed to effect maximum adhesion of the coating to the surface of the IOL insertion cartridge. The successful achievement of this objective, as will be demonstrated, is a fundamental virtue of this family of coatings.
[0032] The base coat may be a polymer or copolymer supplied as a solution in a suitable organic solvent or supplied in the form of an aqueous colloidal dispersion or emulsion or non-aqueous dispersion. The material as supplied may be diluted at the time of use and otherwise formulated with the polyfunctional reagent that will serve to tie the two coats together with chemical bonds, and, in the judgment of the experienced formulator, treated perhaps with a leveling agent and/or a wetting agent, and/or other agents well known in the art that facilitate the formation of stable, uniform, well-adhering coatings.
[0033] The top coat is usually a lubricious water-soluble polymer that can be a polysaccharide, such as hyaluronan, a cellulose derivative, polyacrylic acid and its water soluble copolymers, polyethylene glycol, and the like. The top coat may also be formulated, by dilution and by the addition of surfactant, crosslinking agent, plasticizer, solvent, salts, or leveling agent, and/or other agents that improve the coating and the coating process.
[0034] Clearly the interior surface of the device, through which the IOL is to be inserted, must be immaculately clean and free of oils, greases and dirt. Cleaning, etching, and surface modification by chemical or plasma treatment is especially recommended. Other surface treatments accomplishing similar effects may consist of exposure to an oxidizing acidic reagent such as chromic acid, or corona treatment, or combinations thereof.
[0035] The coating may be applied to the entire device or, preferably, to the inside surface only, and in some cases only to preferred specific areas of the interior of the device, such as the channel of diminished diameter through which the IOL must travel just before entering the eye. There may also be specialized tools to facilitate the entry of the IOL into the incision and into the “bag”, that might benefit from being coated also.
[0036] The formulated base coat may be applied by any convenient method, such as by dipping, spraying, brushing, filling and draining, or by injection from a pipette or other liquid dispenser. During the application of the fluid coatings, drying, and curing, the device may be seated in a bottomless, suitably formed receptacle, or held by friction fit in the open end of a cylindrical tube fitted at the other end in a gas manifold, or by other suitable means. Passing clean dry air, nitrogen, or other inert gas through the device during drying and curing may be desirable as a means of accelerating removal of solvents and other volatile matter.
[0037] After application of the base coat, the device is heated for a brief period, the duration of which depends upon temperature and rate of gas passage over the surface, to remove volatiles. The top coat is then applied by methods similar to those used for the base coat, and heating resumed to remove volatiles and to bring about the grafting reaction between base coat and top coat. At the end of the curing cycle, the coated devices are cooled and then soaked briefly in dilute aqueous NaHCO 3 or other dilute weak base, washed with sterile water and dried.
[0038] The coating made according to the present invention shows exquisite lubricity when it is wet simply with water and/or other aqueous solutions.
[0039] The following examples illustrate the operation of the invention, but should not be construed to limit the invention.
EXAMPLE 1
[0040] After plasma treatment in oxygen, polypropylene cartridges were immersed and gently agitated for 3 minutes in a base coat formulation comprising 100 grams of HYDAK B-23K, 6.87 grams of DESMODUR N-75, and 306.7 grams of HYDAK PMA. HYDAK is a registered trademark of Biocoat Incorporated, of Fort Washington, Pa., and DESMODUR is a registered trademark of Bayer AG. The HYDAK B-23K and HYDAK PMA pertain to the acrylic base coat polymer solution or emulsion, and the trademark DESMODUR pertains to a polyisocyanate cross-linker. The combination of the above ingredients constitutes the base coat.
[0041] The isocyanate serves two purposes. First, it crosslinks the base coat polymer. Secondly, it provides isocyanate groups on the surface of the base coat which are used to tie the top coat to the base coat.
[0042] Each wet device was then attached by friction fit at its distal end to the open end of plastic tubing through which dry air was flowing from a manifold. The temperature of the assembly was raised and held at 60° C. for 20 minutes. The assembly was removed from the oven and allowed to cool for 10 minutes. Air flow was stopped temporarily while the top coat, HYDAK L-110, a solution of hyaluronan, was applied by syringe for the interior length of the device channel. Air flow was restarted, and after 20 to 30 seconds any excess top coat solution that had accumulated at the bottom edge was dabbed off with filter paper. The temperature was raised again to 60° C. and held for 2 hours. After cooling, the devices were removed from the assembly and soaked for 15 minutes in dilute NaHCO 3 , having a concentration of about 0.5%. The concentration need not be precisely 0.5%, but could be in a range of about 0.2 to about 1.0% (w/w). After washing with sterile water and drying, the coated devices were ready for packaging and sterilization.
[0043] When one of these coated devices was immersed briefly in sterile water and then tested with an IOL, the technician reported that the IOL passed through the channel with almost no resistance. In fact, he expressed the opinion that he might feel in better control if slightly higher friction were encountered, but that with further experience he might adjust to the unusual behavior.
EXAMPLE 2
[0044] As a demonstration of the durable security of the coating applied as in Example 1, the formulation and procedures described there were replicated with coatings on one side of each of two polypropylene panels measuring 2.75×6.75×0.25 inches. The panels were mounted, with the coated side facing upward, in a BYK Gardner Abrasion Tester (part No. LAG-8100, available from BYK Gardner USA, of Columbia, Md.), which complies with ASTM method D 2486. While the panels were immersed in deionized water, a brush with stiff nylon bristles under a weight of 450 grams was drawn over the coated surfaces at a rate of 37 cycles per minute. After more than three hundred thousand cycles (more than 600,000 strokes), the coatings had undergone no change: they were still as lubricious as at the start of the test, and the coating had not lost adhesion, flaked, whitened, nor blistered or shown signs of failure of any kind whatever.
[0045] Although polypropylene is an attractive material of construction for the IOL insertion device, because of its low cost, inert character, and well known behavior in conventional molding and processing operations, the uncoated cartridge could be molded from acrylic polymers and copolymers of suitable softening point, nylon, polyester, cellulose acetate or acetate/butyrate, or other moldable polymers well known in the art, and when coated as described here, would serve with virtually identical properties.
[0046] In summary, the IOL insertion device of the present invention is superior to any known heretofore, capable of conveying a foldable IOL with minimum force, without damage, into the eye through a small incision. The channel through which the IOL passes is highly lubricious when wet with water.
[0047] The bilaminar coating formed on the surface of the insertion device is permanent, and does not become dislodged when the IOL is inserted into the eye. Thus, the danger of introducing a foreign lubricant into the eye, during the IOL insertion process, can be eliminated.
[0048] The insertion device, with its lubricious coating, is stable in storage and resistant to abuse, simple in operation, difficult to misuse, and biocompatible.
[0049] The invention can be modified in many ways, within the scope of the preceding disclosure. The specific choice of materials for the base coat and top coat can be varied, as described above. The bilaminar coating may be applied to the entire surface of the IOL insertion device, or it may be applied only to the interior surface defining the channel through which the IOL passes. The coating may also be applied only in the portion of the insertion device having a reduced diameter, where the friction between the insertion device and the IOL is likely to be greatest. These and other modifications, which will be apparent to those skilled in the art, should be considered within the spirit and scope of the following claims. | An insertion device for an intra-ocular lens (IOL) has a bilaminar, lubricious coating on the surface which contacts the IOL as it is being inserted into the eye. The bilaminar coating includes a highly lubricious top coat, and a polymeric base coat which is both highly adherent to the surface of the insertion device, and which has functional groups capable of grafting the base coat to the top coat. In its completed form, the bilaminar coating is essentially permanent, and exceedingly lubricious when wet, allowing the IOL to be advanced smoothly and without damage through the insertion device. The top coat may include hyaluronan, or another material capable of providing the required lubricity. | 0 |
[0001] This application claims benefit of provisional application Ser. No. 60/506,391, filed Sep. 27, 2003.
FIELD OF THE INVENTION
[0002] The present invention relates generally to beverage dispensing equipment, and in particular to specialized nozzles used in beverage dispensing equipment to provide for additive flavors, coloring and the like.
BACKGROUND OF THE INVENTION
[0003] Fountain beverage dispensing equipment is well known in the art and includes various types of machines for dispensing liquid drinks and for making and dispensing slush ice drinks as well. Typically, drinks are dispensed from one or more dedicated valves, each structured to dispense only a single flavor. In order to save space and cost, it is known to have multiple flavor valves that have the capacity to dispense a plurality of flavors from the same nozzle, but such valves dispense only one flavor at a time.
[0004] Various carbonated drinks, particularly cola drinks, have long been available, especially in bottled form with various flavorings such as cherry, vanilla and lemon added to the basic syrup formulation of the drinks. While additive flavors can be included in the syrup formulations as supplied to the drink retailer, such an approach increases the number of dedicated valves that are required. Thus, for example, in addition to a basic cola flavor and its diet counterpart, there would need to be separate valves for cherry and vanilla versions of each, and so on. This number can be increased further if caffeinated and non-caffeinated versions of the beverages are desired. The problem becomes particularly acute for slush ice or so-called frozen carbonated beverage “FCB” dispensing equipment, which typically can only serve two or four flavors per machine and where the cost per flavor is considerably higher than with liquid beverage dispensing equipment.
[0005] Accordingly, it would be desirable to have a mechanism for optionally adding a flavor or flavors to a base drink in such manner that the number of valves, and hence the complexity and cost of the beverage dispensing equipment, can be reduced.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, a device for injecting additive fluids into a stream of a primary fluid comprises a body having a central bore for flow therethrough of the stream of primary fluid, and a plurality of separate fluid flow channels extending through the body. Each fluid flow channel has an inlet for connection to an associated supply of additive fluid and a plurality of outlet orifices opening into the central bore for emission from the outlet orifices of additive fluid from the associated supply and for direction of the emitted additive fluid into the stream of primary fluid flowing through the central bore.
[0007] In accordance with another aspect of the apparatus of the invention, a beverage dispenser comprises a beverage dispensing valve having a nozzle for dispensing a stream of a beverage from the nozzle; and a device for injecting additive fluid flavorings into the stream of beverage. The device comprises a body having a central bore for flow therethrough of the stream of beverage dispensed from the nozzle and a plurality of separate fluid flow channels extending through the body. Each fluid flow channel has an inlet for connection to an associated supply of additive fluid flavoring and a plurality of outlet orifices opening into the central bore for emission from the outlet orifices of additive fluid flavoring from the associated supply of additive fluid flavoring and for direction of the emitted additive fluid flavoring into the stream of beverage flowing through the central bore.
[0008] The invention also contemplates a method of injecting additive fluids into a stream of a primary fluid. The method comprises the steps of providing a body having a central bore; forming a plurality of separate fluid flow channels extending through the body, such that each fluid flow channel has at one end an inlet and at an opposite end a plurality of outlet orifices opening into the central bore; and fluid coupling the inlet to each channel to an associated supply of additive fluid. Also included are the steps of flowing the stream of primary fluid through the central bore; in response to performance of the flowing step, delivering additive fluid from a selected supply thereof to the inlet to the associated channel for flow of the additive fluid through the channel and emission from the outlet orifices from the channel; and directing the additive fluid emitted from the outlet orifices into the stream of primary fluid flowing through the central bore.
[0009] In accordance with another aspect of the method of the invention, additive fluid flavorings are injected into a stream of a beverage dispensed from a nozzle of a beverage dispensing valve of a beverage dispenser. In this aspect of the invention, the method comprises the steps of providing a body having a central bore; forming a plurality of separate fluid flow channels extending through the body, such that each fluid flow channel has at one end an inlet and at an opposite end a plurality of outlet orifices opening into the central bore; and fluid coupling the inlet to each channel to an associated supply of additive fluid flavoring. Also included are the steps of operating the beverage dispensing valve to flow a stream of the beverage through the central bore; in response to performance of the operating step, delivering additive fluid flavoring from a selected supply thereof to the inlet to the associated channel for flow of the additive fluid flavoring through the channel and emission from the outlet orifices from the channel; and directing the additive fluid flavoring emitted from the outlet orifices into the stream of beverage flowing through the central bore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A better understanding of the structure, operation and function of the present invention and the various objects and advantages thereof can be had by reference to the following detailed description which refers to the following figures wherein:
[0011] FIG. 1 shows a pictorial view of the multi-flavor injection device of the present invention as secured to a dispensing valve of a slush ice dispensing machine;
[0012] FIG. 2 shows an enlarged perspective cross-sectional view of the multi-flavor injection device;
[0013] FIG. 3 shows an enlarged perspective bottom view of the multi-flavor injection device;
[0014] FIG. 4A shows a perspective exploded assembly view of a standard slush ice machine dispensing valve together the multi-flavor injection device;
[0015] FIG. 4B shows a perspective view of the standard slush ice machine dispensing valve having the injection device secured thereto, and
[0016] FIG. 5 shows an exploded view of the layered structure of the multi-flavor injection device.
DETAILED DESCRIPTION
[0017] The multi-flavor injection device of the invention will be described for use in connection with a slush ice beverage dispensing machine. As is understood, a slush ice dispensing valve, generally indicated at 1 in FIGS. 1, 4A and 4 B, is secured to a face plate 2 on a front surface of a slush ice beverage dispensing machine. Face plate 2 , as is well known, covers and encloses an open end of a refrigerated freeze cylinder, not shown, in which cylinder a slush ice beverage is prepared and stored for dispensing. Dispensing of the slush ice beverage is achieved by operation of valve 1 , wherein an arm 3 of the valve, having an operating handle 3 a , is manually rotated in the direction of an arrow A. Arm 3 operates against the tension of a spring (not shown) located in a spring housing 4 and is moved in a movement limiting slot 5 to cause a valve mechanism (not shown) to open, thus resulting in a slush beverage flowing out of a dispensing nozzle 6 and into a cup positioned below the nozzle. When the cup is full arm 3 is released by the user and spring tension then moves the arm in the direction of an arrow B to an off position of slush ice dispensing valve 1 , resulting in the closing of the valve mechanism.
[0018] With reference also to FIGS. 2 and 3 , the flavor injection assembly of the invention is adapted to secure to and work with a standard slush dispensing valve 1 . The flavor injection assembly includes an injection device 7 having holes 7 a through which two of four bolts 7 b extend to secure injection device 7 and face plate 2 to the slush beverage dispensing machine, with the bottom two bolts securing injection device 7 and its mounting plate 7 c to face plate 2 . Injection device 7 includes a vertically extending flavor injection channel 8 having an enlarged frustoconical shaped top passage portion 8 a and a lower cylindrical shaped passage portion 8 b . Cylindrical passage portion 8 b includes sixteen flavor injection outlets or orifices extending around a level perimeter therein.
[0019] Referring also to FIG. 5 , the injection device 7 of the invention is comprised of eight generally planar plates or layers I-VIII that are sandwiched together to form injection device 7 . Layer I has a top surface 12 , a bottom surface 14 and a central nozzle receiving and product flow passage portion 15 that extends vertically therethrough and forms a portion (the uppermost portion) of injection passage 8 extending through injection device 7 . Formed into bottom surface 14 of layer I is a first flavor flow channel portion A that includes an inlet portion A 1 , a partial circumferential channel portion A 2 and four outlet channels A 3 .
[0020] Layer II is thicker than layer I as it includes fluidly separate channel portions formed into both top and bottom surfaces thereof as well as a central nozzle receiving and product flow passage portion 15 a that extends vertically therethrough and, along with the passage portion 15 , forms a portion of flavor injection channel or passage 8 of flavor injection device 7 . A top surface 16 of layer II includes a first flavor flow channel “half” B that is complementary in shape and corresponds to and is a mirror image of flavor channel A formed in bottom surface 14 of layer I, so that when layers I and II are brought or sandwiched together channels A and B register with each other. First flavor flow portion B thus includes a corresponding inlet portion B 1 , a partial circumferential portion B 2 and four outlet channels B 3 extending vertically through layer II. A bottom surface 18 of layer II includes a partial second flavor flow channel C formed therein. Channel C includes an inlet portion C 1 , a partial circumferential channel portion C 2 and four outlet channels C 3 .
[0021] A corresponding bottom second flavor flow channel “half” D of second flavor flow channel portion C is formed in a top surface 20 of layer III and includes an inlet portion D 1 , a partial circumferential channel portion D 2 and four outlet channels D 3 . Second flavor flow channel portion D also includes a vertical first flavor inlet channel D 4 extending through layer III. A third flavor flow channel portion E is formed into a bottom surface 22 of layer III. Channel portion E includes an inlet portion E 1 , a partial circumferential channel portion E 2 and four outlet channels E 3 . Layer III also includes a central nozzle receiving and product flow passage portion 15 b that extends vertically therethrough and, along with the passage portions 15 and 15 a , forms a portion of flavor injection channel or passage 8 for receiving dispenser nozzle 6 .
[0022] In a similar manner, a corresponding third flavor flow channel half F of flavor flow channel E is formed in a top surface 24 of layer IV and includes an inlet portion F 1 , a partial circumferential channel portion F 2 and four outlet channels F 3 . Third flavor flow channel portion F also includes a vertical inlet channel F 4 extending through layer IV. A fourth flavor flow channel portion G is formed into a bottom surface 26 of layer IV and also includes an inlet portion G 1 , a partial circumferential channel portion G 2 and four outlet channels G 3 . Layer IV also includes additive fluid channel extensions of the various vertical outlets as well as a passage portion 15 c of passage 8 .
[0023] In a similar manner as described above, a corresponding channel “half” H of flavor channel G is formed in a top surface 28 of layer V and includes an inlet portion HI, a partial circumferential channel portion H 2 and four outlet channels H 3 . Layer V further includes additive flavor outlet channels (not shown) formed in a bottom surface 30 thereof and each such outlet channel includes a vertical channel extending through layer V and including the channel extensions of the other outlets. Layer V further includes a passage portion 15 d of passage 8 .
[0024] A top surface 32 of layer VI includes complementary corresponding “halves” of outlet channels OC that cooperate with those of layer V. Layer VI also includes a central passage portion 15 e that together with the corresponding passage portions 15 and 15 a - 15 d in layers I-V create the central nozzle receiving and flow channel 8 . Together, channel halves OC of layers V and VI create sixteen additive flavor channels terminating at the sixteen flavor injection orifices or outlets extending around a level perimeter on the inner surface of cylindrical channel portion 8 b of passage 8 .
[0025] A bottom surface 34 of Layer VI also includes a first flavor inlet connector bore 36 , a second flavor inlet bore 38 , a third flavor inlet bore 40 and fourth flavor inlet bore 42 . Layer VII includes four bores therethrough that comprise extensions of bores 36 , 38 40 and 42 and are indicated like numerals. Layer VIII includes four further bores therethrough also comprising extensions of bores 36 , 38 40 and 42 and also indicated by like numerals.
[0026] It is contemplated that adhesive be used to secure layers I-VIII together, so that all of the various channel portions fit together and form fluidly separate flow channels, although other suitable means may be used. It is important that these layers be sandwiched together in a manner that they register one on top of the other accurately, and to ensure accurate registration when the layers are sandwiched together registration holes 50 extend through each layer for receiving a pair of vertical registration pins. The registration pins may be firmly anchored in an assembly block and are used to provide for accurate assembly of the layers. After the layers have been glued together any excess material and glue are removed to produce the injector 7 .
[0027] When the layers I-VIII are adhered together to form injection device 7 , four fluidly separate flavor injection channels are formed and exist within the injection device. The first flavor injection channel is formed by the combination of channel portions A and B, the second flavor injection channel by the combination of channel portions C and D, the third by the combination of channel portions E and F and the fourth by the combination of channel portions G and H. Bores 36 , 38 , 40 and 42 receive respective inlet hose connectors 60 for each of four additive flavors that provide for connection of the bores to pressurized sources of additive flavors (not shown).
[0028] An exemplary view of the path traveled through injection device 7 by the various flavors 1 - 4 can be had by referring to FIG. 2 wherein the path in respect of additive flavor 3 is specifically shown. Additive flavor- 3 enters the flavor 3 inlet port, i.e., the bore 38 , and then flows through a flavor 3 passageway 38 a , 38 b to a flavor- 3 -ring 38 c . Additive flavor- 3 then flows around and through flavor 3 ring 38 c and down four flavor 3 down tubes 38 d to four flavor- 3 outlet channels 38 e from whence additive flavor- 3 exits four outlet orifices or orifices 38 f (only three outlets 38 f are shown) into cylindrical passage portion 8 b . It can be appreciated that the four outlet orifices for each of additive flavors 1 - 4 are positioned equidistant around passage portion 8 b . At this point, the flavor additive ejected from the four outlet orifices 38 f is directed into and joins the major flow of the particular frozen slush beverage as it flows through and out of central vertical passage or bore 8 .
[0029] Referring again to FIG. 1 , in use of the injection device 7 a flavor selection mechanism 70 is provided. Flavor selection mechanism 70 includes a horizontal housing portion 72 to which are mounted selection switches 74 a , 74 b , 74 c and 74 d corresponding to each of the four additive flavors. A vertical housing portion 76 is secured to and over spring housing 4 and includes a proximity sensor 78 , indicated by dashed lines. Proximity sensor 78 is retained within housing 76 and senses when valve arm 3 is in the open position, as depicted in FIG. 1 . A suitable electronic control is contained within housing portion 72 and is connected to switches 74 a - d and proximity sensor 78 . When a slush drink is to have a flavor additive, such for example as vanilla, lemon or cherry, the particular switch 74 a - d corresponding to that flavor is first pressed. Arm 3 is then moved to open valve 1 and when arm 3 reaches the valve open position as sensed by proximity sensor 78 , the control circuit operates a solenoid to cause a remote flavor additive valve to open. The flavor additive valves provide for delivery in an on/off manner flow of additive flavors from pressurized sources thereof. Once the remote flavor additive valve is opened, the selected flavor flows from the pressurized source thereof into, through and out of injection device 7 and into the stream of slush beverage as it flows through and is dispensed from the passage 8 in the injection device 7 .
[0030] It is understood that while the injection device 7 of the present invention has been described for use with a slush beverage dispensing machine, that particular environment is intended to be merely illustrative of one of many potential applications for the invention. The injected additive flavor need not be a syrup, but could conceivably be any of a variety of liquids whether potable or not. In fact, the added substance could be a gas as well as a liquid. The present invention also is not limited to injection of just four additives to a fluid stream, but could be used to inject any desired number of additives. Further, more than one such injection device could be used, stacked one on top of the other in order to increase the number of additive fluids that can be injected into a common stream. The invention can also be used to simultaneously inject more than one additive at a time or, if desired, be used in a manner to stagger the injection of multiple different additives during dispensing of a primary fluid. The injection device could also be used such that additive fluid is injected into a primary fluid as it passes, for example, through a pipe, since it is not necessary that the primary fluid be dispensed from the injection device itself.
[0031] While embodiments of the invention have been described in detail, various modification and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims. | A device for injecting additive fluids into a stream of a primary fluid as it passes through a common central bore is characterized by a series of specially formed layers each having a particular fluid flow pattern formed therein. The layers are registered one above the other and sandwiched together to form an integral unit in which there are separate fluid flow channels for each of a desired number of additive fluids. Each channel has an inlet for receiving fluid from an associated pressurized source and a plurality of outlets terminating in angularly spaced relationship around an interior perimeter surface of the common bore. A selection mechanism provides for choosing a desired additive fluid for injection into the primary fluid in a manner coordinated with the flow of the primary fluid through the common bore. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/563,934 filed Apr. 20, 2004 by William D. Wilson, Charlene M. Schaldach, William L. Bourcier, and Phil Paul titled “Computer Designed Nanoengineered Materials for Separation of Dissolved Species.” U.S. Provisional Patent Application No. 60/563,934 filed Apr. 20, 2004 is incorporated herein by this reference.
The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.
BACKGROUND
1. Field of Endeavor
The present invention relates to nanoengineered materials and more particularly to computer designed nanoengineered materials for separation of dissolved species.
2. State of Technology
U.S. patent application Ser. No. 2005/0067341 by Dennis H. Green, George D. Piegols, John A. Lombardi, and Gary Joseph Herbert for a Continuous Production Membrane Water Treatment Plant and Method for Operating Same, published Mar. 31, 2005, provides the following state of technology information, “With water shortages and environmental protection gaining global importance, membrane treatment of contaminated waters is becoming more widespread. Membranes can separate effectively suspended solids, entrained oils and greases, dissolved solids, and dissolved organics, and produce a low contaminant-content permeate water. Membranes can also conserve reagent-loaded matrix waters for recycle and recover valuable metals from metal-loaded waters.”
U.S. Pat. No. 6,841,068 to Sung Ro Yoon, Soon Sik Kim, Hoon Hyung, and Young Hoon Kim issued Jan. 11, 2005 for a domestic nanofiltration membrane based water purifier without a storage tank provides the following state of technology information, “In step with industrial progress, water pollution and water resources scarcity are emerging as severe problems. Because of industrial advancement, population growth, and increased standards of living, the demand to good quality water is increasing rapidly. However, water pollution due to domestic waste or industrial sewage has become a serious problem and therefore, available water has become scarce. In order to utilize limited water resources efficiently, purification treatment is absolutely necessary before drinking natural water is to be consumed, in addition to the removal of sources of water pollution. Conventional water purifiers take forms of different kinds of purification systems depending on filter type. At present, the purification system using a filtration membrane is considered to be the most effective because it can eliminate impurities including minute substances such as bacteria and heavy metals. As representative filtration membranes for use in water purifiers, there exist an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane. Among them, the ultrafiltration membrane is used to remove mainly colloid-sized substances. Although it can provide a high flow rate due to larger pore size than those of the nanofiltration and reverse osmosis membranes, there is a limit to elimination of minute substances such as bacteria and heavy metals.”
The article “Helping Water Managers Ensure Clean and Reliable Supplies” in the July/August 2004 issue of Science & Technology Review provides the following state of technology information, “One of the most important tasks for California water managers is to protect the purity of groundwater, which supplies about half of the state's drinking water. However, since 1988, about one-third of the state wells that supply public drinking water have been abandoned, destroyed, or inactivated, frequently because they have been contaminated with nitrate from fertilized farmland, dairies, feedlots, and septic tanks.”
SUMMARY
Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
The present invention provides computer designed nanoengineered materials for separation of dissolved species. In one embodiment, the present invention provides an apparatus for treatment of a fluid that includes ions comprising a microengineered porous membrane, a system for producing an electrical charge across the membrane, and a series of nanopores extending through the membrane. The nanopores have a pore size such that when the fluid contacts the membrane, the nanopores will be in a condition of double layer overlap and allow passage only of ions opposite to the electrical charge across the membrane. In another embodiment, the present invention provides a method of treatment of a fluid that includes ions. The method comprises the steps of providing a microengineered porous membrane, producing an electrical charge across the membrane, and producing nanopores in the membrane. The nanopores have a pore size such that when the fluid contacts the membrane the nanopores will be in a condition of double layer overlap and allow passage only of ions opposite to the electrical charge across the membrane.
The present invention operates to perform functions such as nitrate removal, water purification, and selective ion transportation. The smart membrane of the present invention provides selective removal of aqueous species from electrolyte solutions. Such a technology could be widely used in the United States because many water supplies have been contaminated by small amounts of toxic substances, such as nitrate, arsenate, perchlorate and others. These substances must be removed before the water can be used for domestic use. The smart membrane of the present invention can be used to extract just those targeted species from the water.
In addition, the smart membrane of the present invention can be used to extract valuable substances from natural or industrial fluids that contain a mixture of species. For example, geothermal fluids contain potentially valuable amounts of lithium that could be marketed provided some technology were available to selectively extract the lithium.
Benefits of the present invention are describe in the article “Helping Water Managers Ensure Clean and Reliable Supplies” in the July/August 2004 issue of Science & Technology Review . “In electrodialysis, transport of either positively charged ions (cations) or negatively charged ions (anions) through copolymer membranes is driven by a voltage applied by a pair of flat electrodes. The ions are driven toward the electrode with the opposite charge. Water flows between alternate cation-permeable and anion-permeable copolymer membrane sheets sandwiched between the electrodes and separated by spacers. As water flows between the membranes, salt is removed from one compartment and concentrated in adjacent compartments, with up to a hundred or more membrane pairs per stack. A manifold separates the exiting fluid into a relatively salt-free permeate product and a salt-enriched brine for disposal . . . The membranes have pores drilled to an optimal size for selective removal of the ions of interest. If the system is optimized for nitrate ions, for example, those ions will preferentially pass through the pores, while others remain with the stream of water. The nitrates can then be collected in the waste stream . . . The team is confident the pores also could be used to trap minor contaminants, such as perchlorate molecules, which typically are present in parts-per-billion concentrations. For those applications, the voltage applied to the membranes would be turned up to electrochemically destroy the perchlorate molecules and, thus, eliminate any waste stream. In a similar manner, a membrane could be designed to selectively remove viruses and then deactivate them. Bourcier foresees specialized membranes for the military, such as a unit mounted on a Humvee to purify brackish water for troops in the field, or membranes designed to remove chemical and biological warfare agents from water. The technology could also be used to purify the wastewater from the production of oil, gas, and coal and to recover metals in industrial wastewater and in silicon chip manufacturing.”
The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate specific embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the specific embodiments, serve to explain the principles of the invention.
FIG. 1 shows an embodiment of a smart membrane system constructed in accordance with the present invention
FIG. 2 shows another embodiment of a smart membrane system constructed in accordance with the present invention that provides selectivity for nitrate removal from water.
FIG. 3 shows another embodiment of a smart membrane system constructed in accordance with the present invention that provides selectivity for arsenic removal from water.
FIG. 4 illustrates a section of a smart membrane with a nanopore.
FIG. 5A illustrates a section of an anion permeable membrane with a nanopore.
FIG. 5B illustrates a section of a cation permeable membrane with a nanopore.
FIG. 6 is a plot illustrating the magnitude of the electric field due to a charged ring of radius R=100 Å as a function of the distances along its axes.
FIG. 7 is a plot showing a comparison.
FIG. 8A is a plot showing dielectrophoretic force.
FIG. 8B illustrates that the slope of the force vs distance curve changes sign.
FIG. 9 is a plot showing the positive and negative surface polarization charges.
FIG. 10 is a plot showing a sum of the positive and negative charges.
FIG. 11 shows results of the calculations.
FIG. 12 shows an electric field profile.
FIG. 13 shows results of dielectrophoretic force calculations.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, to the following detailed description, and to incorporated materials, detailed information about the invention is provided including the description of specific embodiments. The detailed description serves to explain the principles of the invention. The invention is susceptible to modifications and alternative forms. The invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
Referring now to the drawings and in particular to FIG. 1 , an embodiment of a smart membrane system constructed in accordance with the present invention is illustrated. The smart membrane system is designated generally by the reference numeral 100 . The smart membrane system 100 is constructed using computer results in accordance with the present invention. The smart membrane system 100 includes the following structural elements: a cathode 101 , anion permeable membranes 102 , cation permeable membranes 103 , anode 104 and voltage source 105 . The smart membrane system 100 includes anion permeable membranes 102 that have positive surface charge and cation permeable membranes 103 that have negative surface charge.
The smart membrane system 100 operates to perform functions such as nitrate removal, water purification, and selective ion transportation. For example, to provide selectivity for nitrate removal, the anion permeable membranes 102 are nanoengineered to provide relatively rapid nitrate movement through the membrane nanopores. The cation permeable membranes 103 are used for the companion positive charged ions to remove the nitrate salt that could either by re-cycled for use or disposed of.
The smart membrane system 100 comprises a layered stack of membrane materials with through-going pores of a few nanometers in diameter. The pore size is selected such that when exposed to the solution to be treated, the pore will be in a condition of ‘double layer overlap’ and allow passage only of ions opposite in charge to the membrane surface. The surface charge may either be intrinsic (due to hydrolysis of the material surface), or applied by an external potential on a metalized membrane surface. The charge on the membranes alternates from positive to negative through the membrane stack. An electrical potential gradient is placed across the entire membrane stack and used to drive ions though the membranes. The negative ions are drawn toward the anode 101 as illustrated by the arrows 107 . The positive ions are drawn toward the cathode 104 as illustrated by the arrows 108 .
The fluid to be treated is pumped through the membranes as illustrated by the arrows 106 and the targeted species and its counter ion is concentrated in alternate cells. A manifold is attached to the distal end of the device and used to collect the separates. The device is similar to existing electrodialysis equipment in some ways but differs in that only the targeted species is drawn through the membrane, rather than all ions of similar charge type. In this respect, the invention uses less energy and produces a much smaller volume of waste.
The smart membrane system 100 is constructed using computer results in accordance with the present invention utilizing a method of calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element. Different surface elements of the molecule may experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. A single 100 Å radius ring test configuration is employed to facilitate comparison with the well-known point dipole approximation (PDA). The membrane system 100 utilizes agreement between the forces calculated by the BEDF and PDA methods for a 1 Å polarizable sphere. For larger particles, the differences between the methods become qualitative as well as quantitative; the character of the force changes from attractive at the origin of the ring for a 50 Å sphere, to repulsive for a 75 Å sphere. Equally dramatic differences are found in a more complex electrical environment involving two sets of 10 rings.
Dielectrophoresis is increasingly being employed to manipulate and separate molecules and particles including biological cells. Recent developments in nanotechnology enable structures to be built which can create fields and field gradients on unprecedented length scales; the scale of the variations in the field inducing charge on a molecule may be the same as the scale of the molecule itself. Synthetic nanopores have been fabricated in inorganic materials for transporting DNA. Carbon nanotubes have been aligned in a polymer film to demonstrate molecular transport through their cores. Dielectrophoresis has recently been employed to assemble nanowires in suspensions. Multilayer technology enables materials comprised of virtually any elements to be constructed with control on atomic dimensions.
The smart membrane system 100 provides a method for calculation of dielectrophoretic forces in situations where the scale of the variations in the field inducing charge on a molecule may be the same as the scale of the molecule, and whose molecular shape may not be spherical. The results are compared to the analytic (pointdipole approximation, PDA) expressions for the dielectrophoretic force.
The dielectrophoretic force, F, on a dipole, p, in a non-uniform field, E, is given by
F =( p·∇ ) E [1]
For a sphere of radius R having internal dielectric constant 2 in a dielectric medium of dielectric constant 1, the effective dipole moment is
p = 2 π R 3 ɛ 1 ( ɛ 2 - ɛ 1 ɛ 2 + 2 ɛ 1 ) E [ 2 ]
where
ɛ 2 - ɛ 1 ɛ 2 + 2 ɛ 1
is the well-known Clausius-Mossotti factor for a sphere. The dielectrophoretic force in the point-dipole approximation (PDA) becomes
F = 2 π R 3 ɛ 1 ( ɛ 2 - ɛ 1 ɛ 2 + 2 ɛ 1 ) ∇ E 2 [ 3 ]
Equation 3 is applicable to a “small” sphere (although not a point dipole, since it has finite radius, R) in a field, E, which field is assumed to be nonuniform enough to produce appreciably different charges on the positive and negative regions of the induced surface polarization charges, but which nevertheless does not vary so strongly as to alter the size of the dipole throughout the sphere. The dielectrophoretic force calculated using Equation 3 does assume the molecule (“molecule” and “particle” are equivalent for Applicants purposes here) to be a dipole: the magnitudes of the positive and negative induced polarization charges are equal. Equation 3 is recognized as being applicable to the force on a molecule when the dimensions of the variations in the electrostatic potentials and fields are small compared to molecular dimensions.
An alternative expression for the force on a molecule is
F=∫σ ( s ) ds [4]
where σ(s) is the induced surface charge density on an element, s, of the molecular surface and E(s) is the electric field at the surface element having elemental area ds. Equation 4 a) is applicable to arbitrary molecular geometry, b) allows for unequal magnitudes of positive and negative charge to be induced (unlike the dipole approximation), and c) takes account of the precise electric field and, hence, field gradient at every element of the molecule. A molecule whose surface elements experience electric fields whose gradients are not representable by the gradient at say, the centroid, may not be able to be represented by the dipole approximation. Given the charges induced on the surface elements, the energy, W, required to bring the molecule from infinity (a position where the field or field gradient is zero) to its position in the nanostructure is given by
W - 1 2 ∫ ϕ ( s ) ⅆ s [ 5 ]
where φ(s) is the electrostatic potential at the molecular surface element s.
The smart membrane system 100 provides a method of calculation, the Boundary Element Dielectrophoretic Force (BEDF) method, involves first constructing a molecular or solvent accessible surface surrounding the molecule by a method Applicants have previously described. This surface provides the interface between the dielectric media and the molecule; elements of the surface are assigned a unit normal and an elemental area. The electric field, E, created by the nanostructure provides a source of polarization of the molecule. The induced interfacial charge, σ, can be obtained from a straightforward consideration of the electrostatic boundary conditions and self-terms. This leads to a system of linear equations,
{ [ I ] - f [ K ] } [ σ ] = f [ E · n ]
where [ 6 ] K ik = ∫ r ik · n i r ik 3 [ 7 ]
r ik is the vector distance between elements i and k on the molecular boundary; ni is the outward normal at boundary element i; dSk is the differential associated with the area of boundary element k; E·n is the column vector of normal components of the electric field. f is given by, (∈ 2 =1.0 here, but is not restricted to this) and 1 is the dielectric constant of the solvent (∈ 1 =78.5 for water here, but, again, is not restricted to this.).
Solution of Equation by the usual methods of linear algebra provides the polarization charge, σ, created by E at each surface element. In this way, different surface elements of the molecule are allowed to experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. The field gradient, variations in the field over the scale of the molecule, is properly taken into account.
A simple charged ring of radius R=100 Å provides an interesting test case. The axial electric field has variations over length scales of the order of its radius which serve to illustrate several important features. The potentials and fields can be calculated analytically and can also be obtained numerically by constructing the ring of small Debye-Huckel atoms (spheres) and performing a direct summation of their individual contributions. The membrane system 100 provides the numerical method to facilitate investigation into more complicated structures to be described below. In these demonstration calculations, each atomic element of the ring was given a charge of 0.1 electrons; the magnitude of the fields and forces in this test case are small but obviously scale with the charge.
The membrane system 100 provides a method for calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element. Different surface elements of the molecule may experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. A single 100 Å radius ring test configuration is employed to facilitate comparison with the well-known point dipole approximation (PDA). Applicants find remarkable agreement between the forces calculated by the BEDF and PDA methods for a 1 Å polarizable sphere. However, for larger particles, the differences between the methods become qualitative as well as quantitative; the character of the force changes from attractive at the origin of the ring for a 50 Å sphere, to repulsive for a 75 Å sphere. Equally dramatic differences are found in a more complex electrical environment involving two sets of 10 rings.
Referring now to FIG. 2 , another embodiment of a smart membrane system constructed in accordance with the present invention is illustrated. This embodiment of a smart membrane system is designated generally by the reference numeral 200 . The smart membrane system 200 provides selectivity for nitrate removal from water.
The article “ Helping Water Managers Ensure Clean and Reliable Supplies ” in the July/August 2004 issue of Science & Technology Review states, “Most Americans take cheap and plentiful supplies of pure drinking water for granted. Some even consider it to be an inalienable right. However, clean water sources, especially pristine underground aquifers, are being consumed at an increasing rate, and contaminants and changing patterns in rain and snowfall are threatening the adequacy of supplies . . . One of the most important tasks for California water managers is to protect the purity of groundwater, which supplies about half of the state's drinking water. However, since 1988, about one-third of the state wells that supply public drinking water have been abandoned, destroyed, or inactivated, frequently because they have been contaminated with nitrate from fertilized farmland, dairies, feedlots, and septic tanks.
Nitrate, a nitrogen-oxygen compound, is a significant source of nitrogen, an essential nutrient. However, high levels of nitrate in drinking water can cause serious illness and sometimes death. Nitrate poses a special risk for infants. It can diminish the oxygen-carrying capacity of an infant's blood (called blue baby syndrome), which can lead to death. High nitrate levels can also harm the ecosystems of lakes, streams, and the coastal ocean.”
The smart membrane system 200 includes the following structural elements: a cathode 201 , an anion permeable membrane 202 , an anode 203 , and a voltage source 204 . The anion permeable membrane 202 is nanoengineered to provide relatively rapid nitrate movement through the membrane nanopores. The membrane system 200 utilizes the permeable membrane 202 made of a membrane material with through-going pores of a few nanometers in diameter. The membrane 202 is produce by drilling pores through the membrane. The pores are drilled to an optimal size for selective removal of the ions of interest. The pore size is selected such that when the water to be treated is passed along the permeable membrane 202 , the pores will be in a condition of “double layer overlap” and allow passage only of ions opposite in charge to the membrane surface.
The smart membrane system 200 is constructed using computer results in accordance with the present invention utilizing a method of calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element.
The smart membrane system 200 provides a method for calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element. Different surface elements of the molecule may experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. A single 100 Å radius ring test configuration is employed to facilitate comparison with the well-known point dipole approximation (PDA).
The voltage source 204 is used to crate an electrical potential gradient across the membrane 202 and used to drive the nitrate ions (NO 3 ) − though the membrane 202 as illustrated by the arrow 207 . The nitrate ions (NO 3 ) − are drawn toward the cathode 101 as illustrated by the arrow 107 .
The fluid to be treated is pumped through the smart membrane system 200 . The targeted species nitrate ions (NO 3 ) − is drawn through the permeable membrane 202 and produces the fluid flow 205 that is a nitrate enriched brine. The nitrate depleted water continues through the membrane system 200 as illustrated by the arrow 206 . The voltage source 204 is used to crate an electrical potential gradient across the membrane 202 and used to drive the nitrate ions (NO 3 ) − though the membrane 202 as illustrated by the arrow 207 . The nitrate ions (NO 3 ) − are drawn toward the cathode 101 as illustrated by the arrow 107 . The fluid to be treated is pumped through the smart membrane system 200 . The targeted species nitrate ions (NO 3 ) − is drawn through the permeable membrane 202 and produces the fluid flow 205 that is a nitrate enriched brine. The nitrate depleted water continues through the membrane system 200 as illustrated by the arrow 206 . In the membrane system 200 the pores are created with an etching process using ion-beam technology. For nitrate treatment, the membrane pores are about 10 nanometers in diameter. Current membrane samples contain about 1 billion holes per square centimeter.
Referring now to FIG. 3 , another embodiment of a smart membrane system constructed in accordance with the present invention is illustrated. This embodiment of a smart membrane system is designated generally by the reference numeral 300 . The smart membrane system 300 provides selectivity for arsenic removal from water.
The smart membrane system 300 includes the following structural elements: a cathode 301 , a permeable membrane 302 , an anode 303 , and a voltage source 304 . The permeable membrane 302 is nanoengineered to provide relatively rapid arsenic movement through the membrane nanopores. The smart membrane system 300 utilizes the permeable membrane 302 made of a membrane material with through-going pores of a few nanometers in diameter. The membrane 302 is produce by drilling pores through the membrane. The pores are drilled to an optimal size for selective removal of the ions of interest.
The pore size is selected such that when the water to be treated is passed along the permeable membrane 302 , the pores will be in a condition of “double layer overlap” and allow passage only of ions opposite in charge to the membrane surface.
The smart membrane system 300 is constructed using computer results in accordance with the present invention utilizing a method of calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element.
The smart membrane system 300 provides a method for calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element. Different surface elements of the molecule may experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. A single 100 Å radius ring test configuration is employed to facilitate comparison with the well-known point dipole approximation (PDA).
The voltage source 304 is used to crate an electrical potential gradient across the membrane 302 and used to drive the arsenic ions (As) − though the membrane 302 as illustrated by the arrow 307 . The arsenic ions (As) − are drawn to the cathode 101 as illustrated by the arrow 107 .
The fluid to be treated is pumped through the smart membrane system 300 . The targeted species arsenic ions (As) − is drawn through the permeable membrane 302 and produces the fluid flow 305 that is an arsenic enriched brine. The arsenic depleted water continues through the smart membrane system 300 as illustrated by the arrow 306 .
Referring now to FIG. 4 , a section of a smart membrane with a nanopore is illustrated. This illustration of a smart membrane with a nanopore is designated generally by the reference numeral 400 . The smart membrane with a nanopore 400 includes a permeable membrane 401 and a nanopore 403 .
The smart membrane with a nanopore 400 is nanoengineered to provide relatively rapid ion movement through the nanopore 402 . The nanopore 402 is a few nanometers in diameter. Pore diameter smaller than double-layer thickness causes “double layer overlap” and results in ion permselectivity. Negative surface charge allows transport of positive ions. Positive surface charge allows transport of negative ions. The pore size is selected such that when the fluid to be treated is passed along the permeable membrane 401 , the nanopore 402 will be in a condition of “double layer overlap” and allow passage only of ions opposite in charge to the charge of the membrane 401 . As illustrated, the negative ion 405 passes through the nanopore 402 as indicated by the arrow 406 .
Referring again to FIG. 4 , the permeable membrane 401 is an anion permeable membrane with a positive charge. The positive charge of the permeable membrane 401 is indicated at 403 . This produces negative charges inside the nanopore 402 . The negative charges inside the nanopore 402 are identified at 404 . The pore size has been selected such that the nanopore 402 is in a condition of “double layer overlap” and allows passage only of negative ions 405 . The negative charges inside the nanopore 402 are in a condition of “double layer overlap.” There are no positive charges inside the nanopore 402 . The negative charges 404 are so close together they prevent positive ions from passing through the nanopore 402 .
The nanopore 402 size has been selected using computer results in accordance with the present invention utilizing a method of calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element.
The present invention provides a method for calculation of the dielectrophoretic force on a nanoparticle in a fluid environment where variations in the electric field and electric field gradients are on the same nanoscale as the particle. The Boundary Element Dielectrophoretic Force (BEDF) method involves constructing a solvent-accessible or molecular surface surrounding the particle, calculating the normal component of the electric field at the surface boundary elements and then solving a system of linear equations for the induced surface polarization charge on each element. Different surface elements of the molecule may experience quite different polarizing electric fields, unlike the situation in the point dipole approximation. A single 100 Å radius ring test configuration is employed to facilitate comparison with the well-known point dipole approximation (PDA).
As explained previously, the smart membrane system operates by the voltage source creating an electrical potential gradient across the permeable membrane 401 and the electrical potential gradient is used to drive the ions 405 though the nanopore 402 in the permeable membrane 401 as illustrated by the arrow 406 . The article “ Helping Water Managers Ensure Clean and Reliable Supplies ” in the July/August 2004 issue of Science & Technology Review describes the smart membranes, “Livermore's modified electrodialysis technology replaces the solid polystyrene membranes with “smart” membranes of gold-coated polycarbonate. By specifying the pore size, voltage, and electric field that will best attract and isolate a target contaminant, researchers can design each membrane to selectively remove only one contaminant of interest . . . Pores Drilled in Smart Membranes—The membranes have pores drilled to an optimal size for selective removal of the ions of interest. If the system is optimized for nitrate ions, for example, those ions will preferentially pass through the pores, while others remain with the stream of water. The nitrates can then be collected in the waste stream.” The article “ Helping Water Managers Ensure Clean and Reliable Supplies ” in the July/August 2004 issue of Science & Technology Review is incorporated herein by reference.
Referring now to FIGS. 5A and 5B sections of smart membranes are shown with each smart membrane illustrating a nanopore constructed in accordance with the present invention. FIG. 5A is an illustrations of a section of an anion permeable membrane with a nanopore. FIG. 5B is an illustration of a section of a cation permeable membrane with a nanopore. The fluid to be treated is pumped into contact with the membranes and the targeted species ion and its counter ion are concentrated by passing through the nanopore in the anion permeable membrane and the nanopore in the cation permeable membrane respectively.
Referring now to FIG. 5A , a smart anion permeable membrane is designated by the reference numeral 500 . The anion permeable membrane 500 includes nanopores. A nanopore 501 is shown for illustration purposes.
The anion permeable membrane 500 has a positive charge. The positive charge of the anion permeable membrane 500 is indicated at 502 . The positive charge 502 of the anion permeable membrane 500 produces negative charges inside the nanopore 501 . The negative charges inside the nanopore 501 are indicated at 503 . The pore size has been selected such that the nanopore 501 is in a condition of “double layer overlap” and allows passage only of negative ions such as the NO 3 ion 504 . The negative charges 503 inside the nanopore 501 are shown in the condition of “double layer overlap.” There are no positive charges inside the nanopore 501 . The negative charges 503 are so close together they prevent positive ions from passing through the nanopore 501 .
Referring now to FIG. 5B , a smart cation permeable membrane is designated by the reference numeral 505 . The cation permeable membrane 505 includes nanopores. A nonopore 506 is shown for illustration purposes.
The cation permeable membrane 505 has a negative charge. The negative charge of the cation permeable membrane 505 is indicated at 507 . The negative charge 507 of the cation permeable membrane 505 produces positive charges inside the nanopore 506 . The positive charges inside the nanopore 506 are indicated at 508 . The pore size has been selected such that the nanopore 506 is in a condition of “double layer overlap” and allows passage only of negative ions such as the Na ion 509 . The positive charges 508 inside the nanopore 501 are shown in the condition of “double layer overlap.” There are no negative charges inside the nanopore 506 . The positive charges 508 are so close together they prevent negative ions from passing through the nanopore 506 .
Referring again to FIGS. 5A and 5B , the smart membranes 500 and 505 provide selective removal of aqueous species from an electrolyte fluid. The fluid to be treated is pumped into contact with the membranes 500 and 505 and the targeted species NO 3 ion 504 and its counter Na ion 509 are concentrated by passing through the nanopores 501 and 506 . The anion permeable membrane 500 has a positive charge 502 . The positive charge 502 of the anion permeable membrane 500 produces negative charges 503 inside the nanopore 501 . The negative charges 503 are in a condition of “double layer overlap” and allow passage only of negative ions such as the NO 3 ion 504 . The cation permeable membrane 505 has a negative charge 507 . The negative charge 507 of the cation permeable membrane 505 produces positive charges 508 inside the nanopore 506 . The positive charges 508 are in a condition of “double layer overlap” and allow passage only of negative ions such as the Na ion 509 .
Referring now to FIG. 6 , a plot illustrates the magnitude of the electric field, |E|, due to a charged ring of radius R=100 Å as a function of the distance, z, a) along its axis, x=y=0.0 (solid line, filled circles) and also b) along an axis at x=75.0 Å, y=0 (solid line alone). Note that |E| along the x=0 axis has maxima at zm=±(sqrt(2)/2)R (˜70.7 Å); along the x=75.0 Å axis, a single maximum in |E| is seen at z=0.0. This shift in the peak of the magnitude of the field is caused by the increase in the off-axis x-component at x=75.0 Å (short-dashed line). The z-component of the electric field along the x=75.0 Å axis (long-dashed line), changes sign at z=0 and has its own extrema at ±25.4 Å (±48 Bohr); nevertheless, the x-component, peaked at z=0.0, dominates the field magnitude off-axis (x=75.0 Å).
FIG. 6 , also shows that the x-component also exhibits small peaks at z=84.1 Å (150 Bohr). (The y-component of the electric field is zero in both cases because of the symmetry.) The z-component of the electric field along the x=75.0 Å axis, also shown in FIG. 6 (long-dashed line), changes sign at z=0 and has its own extrema at ±25.4 Å (±48 Bohr); nevertheless, the x-component, peaked at z=0.0, dominates the field magnitude off-axis (x=75.0 Å).
Next, the dielectrophoretic force (DF) on a sphere of radius Rm=1 Å was calculated as a function of its axial distance, z, along the ring axis (x=y=0.0) using both the point-dipole approximation (PDA, Equation 3 above) and the BEDF method (Equation 4 above).
The results of this comparison are shown in FIG. 7 . It is first of all to be noted that, for this small molecule, these very different methods of calculation are in remarkable agreement with each other. The DF is negative for small z>0 (molecule is being attracted backward toward the ring center) and positive for small z<0 (molecule is being attracted toward the ring center) indicating that the molecule is trapped at the ring center. In the region −zm<z<zm, the induced polarization charge on the surface elements of the sphere nearest the ring center is found by direct solution to Equation 6 to be positive, while those elements furthest from the ring are determined to be negatively charged. The electric field in this region is growing in magnitude (see FIG. 4 ) and, although there is an excess of positive charge induced (more about this below) the force on the negative charge exceeds that on the positive charge, making the total force negative as indicated in FIG. 7 . When the molecule is along the z-axis at z>zm, the sign of the induced polarization charges is as for z<zm but now the magnitude of the electric field is diminishing. Consequently, the positive surface charge interacts with a larger electric field and the total force on the molecule becomes positive. Note from FIG. 7 that this occurs at z=zm where the peak in the magnitude of the electric field, |E|, is seen to occur (see FIG. 6 ). Similar effects occur at z<−zm. Whereas the region near the ring origin is attractive, the region near the extrema in the electric field is repulsive. The dielectrophoretic energy calculated from the induced charges and the electrostatic 10 potential (Equation 7 above), also plotted in FIG. 7 (solid line, open circles) reflects these effects: For example, a minimum in the energy is seen to occur where the force has a negative slope as it goes through zero, but an energy maximum occurs when the force goes through zero with positive slope.
Note, from FIG. 7 , there are deviations between the point-dipole and BEDF methods near the extrema. The point-dipole approximation gives consistently larger magnitude forces than the BEDF method. This deviation is caused by the dipole (equal positive and negative charges) approximation. Applicants find that for −zm<z<zm there is an excess of positive charge induced (resulting from the x-component of the field) on the elements nearest the origin while for |z|>zm an excess of negative charge is induced on those elements furthest from the origin. These excess charges in each case interact with the lower magnitude electric field at those elements, thus leading to a slightly reduced force. This excess charge effect becomes more serious for larger molecules (particles), as will be see.
In FIG. 8A , a plot shows the dielectrophoretic force on spheres of radius 50 Å and 75 Å as a function of distance, z, along the ring axis (x=y=0), again calculated in the pointdipole approximation (PDA) and by the BEDF method. The two methods give similar characteristics, albeit different magnitudes, for the 50 Å sphere: Positive force for small z<0 and negative force for small z>0 as found for the 1 Å sphere in FIG. 5 . As for the 1 Å sphere, the point-dipole approximation predicts higher magnitude forces because of the x-component of the off-axis electric field at the molecular surface elements. At x=75 Å, the surface elements of the sphere experience dramatically different electric fields (even a 11 shift in the peaks of |E|: see FIG. 8 ) which dramatically change the character of the dielectrophoretic force. FIG. 8A illustrates that the slope of the force vs distance curve changes sign. This is a quantitative and qualitative change in the force from attractive for the 50 Å molecule to repulsive for the 75 Å molecule. The PDA predicts both molecules to be attracted toward the center. In addition, the PDA predicts repulsion at the peaks in the field, i.e., the slope of the DF vs distance curve is positive as the force goes through zero, while the BEDF method exhibits no such repulsive behavior at the peaks.
FIG. 8B is an expanded inset region noted in FIG. 8A for 50 Å and 75 Å spheres and include the dielectrophoretic force for a 65 Å sphere. This intermediate-sized sphere shows a weak attraction, reduced by an order of magnitude from the force on the 50 Å sphere and shows the transition in the slope of the force taking place as a function of sphere radius. It is interesting to note from FIG. 8B that the dielectrophoretic force on a 50 Å sphere moved along z at the x=30 Å off-axis position exhibits similar behavior to the 65 Å sphere moved on-axis. As the off-center sphere moves far from the ring center (not shown), it follows the behavior for the 50 Å on-axis sphere.
A better understanding of these effects involves the induced surface polarization charges (more precisely, the normal component of the electric field at molecular surface elements, see Equation 6.) In FIG. 9 , a plot shows the positive and negative surface polarization charges on the elements of the 1 Å and 75 Å spheres as a function of the position of the centroid of each molecule. (These charges are obviously separated from each other.) For the 1 Å sphere, there is found two extrema each for the positive and negative charges, these extrema coinciding with the maxima in the magnitude of the 12 electric field, zm, for the 1 Å sphere shown in FIG. 6 . For the 75 Å sphere, the positive and negative induced charges have a markedly different character: a single extremum at the ring origin (z=0) is found for each.
In FIG. 10 , there is a sum these positive and negative charges and plot the total induced charges on each of the two spheres as a function of the position of their centroids along the ring axis. For both spheres, there is found an increase in total induced positive charge near the origin (lines with open and closed circles) resulting from the x-component of the electric field (actually, from the large normal component, E·n, see Equation 6 and FIG. 6 ). As discussed above, for the small sphere, the negative charge induced on the leading edge of the molecule as it moves toward positive z values interacts with the large electric field at those leading elements resulting in a negative force. The excess positive charge induced by the x-component of the field on the small sphere multiplied by the z-component of the field at those elements is insufficient to overcome this negative force. On the other hand, in the case of the 75 Å sphere, there is a large increase in positive charge on elements of the sphere near the origin E·n again), and now this increase in positive charge, even though multiplied by a smaller field, is sufficient to overcome the larger field at the leading negative elements of the molecule. The character of the force changes from attractive to repulsive.
Additional understanding of this effect comes from performing similar calculations, determining the induced charges, in the absence of an x-component of the field. In FIG. 10 , then, there is plotted the total induced charges for the 1 Å and 75 Å sphere when the field is (fictitiously) entirely along the z-axis (lines with open and closed squares). Here there is found an excess negative charge is induced for −zm<z<zm consistent with the larger field magnitude being near the origin, while for |z|>zm the induced polarization charge is positive, again consistent with the magnitude of the field at those furthermost elements from the origin. The magnitude of this effect is greater for the larger sphere; the point along z where the sign change occurs also differs somewhat because of the size, i.e., the location of the elements at which the charge is being induced. These calculations provide direct evidence of the influence of the x-component of the field on the induced charges and hence the character of the dielectrophoretic force.
The point-dipole approximation assumes the molecule to be spherical; the BEDF method presented here allows us to investigate shape effects. To this end, using the method described above, Applicants constructed a molecular surface surrounding a 10×10 atom planar molecule (“face-centered-cubic-like” geometry, radius of each atom, 1.2 Å) and then calculated the dielectrophoretic force on that planar molecule in the same ring environment as above. In FIG. 11 , Applicants present the results of these calculations when the plane of the molecule is the same as the ring (labeled “parallel” in FIG. 11 ) and also when the molecule is rotated 90 degrees about the x-axis so its normal is perpendicular to the plane of the ring (“perpendicular” in FIG. 11 ). Both orientations give rise to attractions to the origin and repulsions at the maxima of the electric field (zm in FIG. 2 ), the force changing sign appropriately at these critical points. The parallel orientation results in forces which can be a factor of 2-3 greater than the parallel configuration. From FIG. 11 , Applicants find the binding energy (difference in energy between the energy maxima and minima) for the parallel configuration is nearly twice the binding of the perpendicular geometry. These calculations indicate that shape effects must be considered when calculating dielectrophoretic forces on this scale.
As discussed above, nanotechnology has enabled interesting and technologically relevant geometrical configurations to be produced. Notable among these are multilayers or nanolaminates where atomic-scale layers of different materials can be produced adjacent to one another with single atom interfaces between them. Optimizing a nanoscale geometry is beyond the scope of this work; Applicants calculated the electric fields for a set of rings which is illustrative of the enabling power of the technology while providing further examples of the need to calculate dielectrophoretic forces using a molecular theory appropriate to these nanoscale configurations. When multiple rings are employed, the fields become more interesting. N rings of the same charge placed next to each other result in both an increase in the magnitude of the resulting field and a decrease in the position of the extrema relative to the plane of the end ring. An oppositely charged set of N rings could be configured along the same axis as the first at a distance chosen to optimize the magnitude of the field in-between the sets of rings.
A single set of 10 coaxial rings, axis along z, radius 100 Å, comprised of atoms each having a charge of +0.1 electrons as for the single ring above, placed next to each other in a row, will produce the electric field profile shown in FIG. 12 . The set, or layer, has a charge density of ˜3.4 μC/cm2. The “leftmost” ring is placed (in the x-y plane) at z=0; the electric field is zero in the middle of the 10-ring configuration (at 19 Bohr=10.1 Å) and directed positively along the z-axis. A second 10-ring configuration, this time negatively charged, coaxial with the first (see FIG. 12 ) will also produce an electric field directed positively along the z-axis. By spacing the 10-ring sets so the extrema in the zcomponent of their electric fields coincide (separation=123.3 Å (233 Bohr)), Applicants optimize the field at 154 Bohr (81.5 Å), the mid-point between the rings (see FIG. 12 ). As can be seen in FIG. 7 , this 2×10 ring configuration also gives rise to zeroes in the field at −15.3 Å (−29 Bohr) and 177.8 Å (336 Bohr) as well as secondary peaks at −73.6 Å (−139 Bohr) and 236.0 Å (446 Bohr).
The off-axis electric field for this 2×10 ring configuration is dramatically different from that along the axis. In FIG. 12 , Applicants have also plotted the x-component and magnitude of the electric field for the 2×10 ring configuration along the z-axis at x=75 Å. The large xcomponent in the middle of the rings is responsible for the double-peaked character of the magnitude.
In FIG. 13 , Applicants show the results of Applicants dielectrophoretic force calculations for a 75 Å and 90 Å sphere in the 2×10 ring environment described above using the BEDF method and, for comparison, the PDA method for the 75 Å sphere. (The PDA method for the 90 Å sphere shows the same behavior as the 75 Å, with its magnitude adjusted for the radius.) The PDA predicts an attraction (negative slope of DF vs z as it goes through zero) where the electric field is zero (−29 Bohr and 336 Bohr) and a repulsion (positive slope of DF vs z as it goes through zero) where the secondary peaks in |E| occur (see FIG. 10 ). The BEDF method predicts no attractions or repulsions in these regions. Strikingly, at the maximum in the |E| field for the 2×10 ring, (see x=0.0 |E| field (z=154 Bohr) in FIG. 8 ), the BEDF and PDA methods applied to the 75 Å sphere agree as to the repulsive character of the force (positive slope of DF vs z as it goes through zero). However, the methods produce opposite characters for the force on a 90 Å sphere: The dielectrophoretic force on a 90 Å sphere in the field maximum is attractive according to the BEDF method. The PDA is probing the field and field gradient along the axis of the 2×10 ring configuration, while the molecular surface elements at which the charge is being induced are probing quite different regions because of the scale of the field variations (see FIG. 12 ).
The smart membrane of the present invention provides selective removal of aqueous species from electrolyte solutions. Such a technology could be widely used in the United States because many water supplies have been contaminated by small amounts of toxic substances, such as nitrate, arsenate, perchlorate and others. These substances must be removed before the water can be used for domestic use. The smart membrane of the present invention can be used to extract just those targeted species from the water.
In addition, the smart membrane of the present invention can be used to extract valuable substances from natural or industrial fluids that contain a mixture of species. For example, geothermal fluids contain potentially valuable amounts of lithium that could be marketed provided some technology were available to selectively extract the lithium.
The smart membrane of the present invention can have a dual purpose: removal of toxic species such as arsenic or selenium in order to produce potable water for drinking; and extraction of valuable species such as lithium or gold for marketing. Existing methods for selective removal include ‘bulk’ methods that remove all other salts in addition to the targeted species. These methods include reverse osmosis, electrodialysis, and the use of coagulants to remove the targeted species as a sorbant on the floc. The coagulant method is commonly used in water treatment plants. These methods are energy intensive because they remove many benign species as well as the target. The coagulant process is very labor intensive. Ion exchange is a selective method that uses ion exchange resins that absorb the targeted species. The ion exchange method is also very labor intensive and produces a secondary waste stream.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. | A computer designed nanoengineered membrane for separation of dissolved species. One embodiment provides an apparatus for treatment of a fluid that includes ions comprising a microengineered porous membrane, a system for producing an electrical charge across the membrane, and a series of nanopores extending through the membrane. The nanopores have a pore size such that when the fluid contacts the membrane, the nanopores will be in a condition of double layer overlap and allow passage only of ions opposite to the electrical charge across the membrane. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for producing alkenyl ethers. More particularly it relates to a process for producing an α,β-unsaturated ether, an unsaturated ether having conjugated double bonds, a hydroxyalkenyl ether or a hydroxyalkenyl ether having conjugated double bonds.
2. Description of the Related Art
As to conventional processes for producing α,β-unsaturated ethers, for example the following synthesis is disclosed in J. Org. Chem., 23, 670 (1958): ##STR4##
Namely, from 2-ethylhexylaldehyde of the formula 3 and 2-ethylbutyl alcohol of the formula 4 is prepared 1-chloro-2-ethylhexyl-2'-ethylbutyl ether of the formula 5 , which is converted into 1-acetoxy-2-ethylhexyl-2'-ethylbutyl ether of the formula 6 , from which acetic acid is removed in gas phase at 230° C., to prepare 2-ethylhexenyl-2-ethylbutyl ether of the formula 7 . In general, most of production processes of α,β-unsaturated ethers have been carried out by subjecting acetals to catalytically thermal decomposition in gas phase at a high temperature of 300° to 800° C., as disclosed in Japanese patent application laid-open No. Sho 57-185232/1982, etc.
However, such conventional production processes of α,β-unsaturated ethers have drawbacks of requiring two or three steps starting from aldehydes and also requiring high temperatures in gas phase reaction.
Further, as to the production process of an unsaturated α,β-ether having conjugated double bonds, the following synthesis is disclosed in J. Polym. Sci., Part A-1, Vol. 9, 164, 1971: ##STR5##
Namely, from an unsaturated aldehyde and an alcohol is prepared a 3-alkoxyacetal in the presence of an alkali catalyst, followed by removing the alcohol from the acetal in liquid phase in the presence of an acidic catalyst to prepare an unsaturated ether having conjugated double bonds.
However, this synthesis also requires two stages.
Thus, a commercial production process wherein the number of steps starting from aldehydes is small and the reaction is carried out under mild conditions has been desired.
Next, the prior art of production process of hydroxyalkenyl ethers among unsaturated ethers having conjugated double bonds will be described.
A synthesis of a vinyl ether among hydroxyalkenyl ethers is disclosed in U.S. Pat. No. 3,429,845 or Ann. Chem., 601, 81 (1956). In this synthesis, an alkane diol is added to acetylene. However, according to such a process, high temperature and high pressure are required for the reaction, and byproducts such as a divinyl compound (CH═CHOAOCH═CH) or a cyclic acetal are formed in a large quantity; hence the process is unsuitable as a commercial means.
On the other hand, a process of reacting ethanediol with an alkyl vinyl ether in the presence of mercuric acetate is disclosed in J. Am. Chem. Soc., 79, 2828 (1957). According to this process, main products are dioxolan and divinyl ether and 2-hydroxyethyl vinyl ether forms as a byproduct; hence it is impossible to employ this process as a production process of hydroxyalkenyl ethers.
Since such a hydroxyalkenyl ether having conjugated double bonds has conjugated double bonds, the ether can be expected as a functional monomer. Such a hydroxyalkenyl ether having conjugated double bonds is a novel substance.
As apparent from the foregoing, the object of the present invention is to provide a process for producing alkenyl ethers from an aldehyde at one step and under mild reaction conditions.
SUMMARY OF THE INVENTION
The present invention has the following main constitution 1) and constitutions as embodiments 2)-5):
1) A process for producing an alkenyl ether, which comprises reacting an aldehyde expressed by the formula (1) ##STR6## with an alcohol of the formula (2)
R.sup.3 --OH (2)
in the presence of an acidic catalyst in liquid phase, to produce an alkenyl ether expressed by the formula (3) ##STR7## wherein R 1 represents an alkyl group of 2 to 8 carbon atoms, R 4 represents hydrogen atom or R 1 and R 4 each represent R--CH 2 --CH═group wherein R represents an alkyl group of 1 to 8 carbon atoms; R 2 represents an alkyl group of 1 to 6 carbon atoms; R 3 represents a linear or branched alkyl group of 4 to 24 carbon atoms, a cycloalkyl group of 4 to 15 carbon atoms, preferably 4 to 7 carbon atoms, a linear or branched oxyalkyl group of 5 to 10 carbon atoms, an oxycycloalkyl group of 4 to 15 carbon atoms, preferably 4 &o 7 carbon atoms or ##STR8## wherein R' represents hydrogen atom or methyl group and n represents an integer of 2 to 20; and R 5 represents an alkyl group of 2 to 8 carbon atoms or R--CH═CH--group wherein R is as defined above.
2) A process for producing an alkenyl ether according to item 1), which comprises reacting an aldehyde expressed by the formula ##STR9## with an alcohol expressed by the formula
R.sup.3 '--OH (2-1)
in a molar ratio of 0.1:1 to 10:1, in the presence of an acidic catalyst in liquid phase, to produce an α,β-unsaturated ether expressed by the formula ##STR10## wherein R 1 represents an alkyl group of 2 to 8 carbon atoms, R 2 represents an alkyl group of 1 to 6 carbon atoms and R 3 ' represents a linear or branched alkyl group of 4 to 24 carbon atoms or a cycloalkyl group of 4 to 15 carbon atoms, preferably 4 to 7 carbon atoms.
3) A process for producing an alkenyl ether according to item 1), which comprises reacting an aldehyde expressed by the formula ##STR11## with an alcohol expressed by the formula
R.sup.3 '--OH (2-1)
in the presence of an acidic catalyst in liquid phase, to produce an unsaturated ether having conjugated double bonds expressed by the formula ##STR12## wherein R represents an alkyl group of 1 to 6 carbon atoms, R 2 represents an alkyl group of 1 to 6 carbon atoms and R 3 ' represents an alkyl group of 4 to 24 carbon atoms or a cycloalkyl group of 4 to 15 carbon atoms, preferably 4 to 7 carbon atoms
4) A process for producing an alkenyl ether according to item 1), which comprises reacting an aldehyde expressed by the formula ##STR13## with a diol expressed by the formula
HOAOH (2-2)
or the formula ##STR14## in a molar ratio of 0.05:1 to 10:1, in the presence of an acidic catalyst and in liquid phase, to produce a hydroxyalkenyl ether expressed by the formula ##STR15## wherein R 1 represents an alkyl group of 2 to 8 carbon atoms, R 2 represents an alkyl group of 2 to 6 carbon atoms, R' represents hydrogen atom or methyl group, n represents an integer of 2 to 20 and A represents a linear, branched or cyclic alkylene group of 5 to 10 carbon atoms.
5) A process for producing an alkenyl ether according to item 1), which comprises reacting an aldehyde expressed by the formula ##STR16## with a diol expressed by the formula
HOAOH (2-2)
or ##STR17## in a molar ratio of 0.05:1 to 10:1, in the presence of an acidic catalyst and in liquid phase, to produce a hydroxyalkenyl ether having conjugated double bonds, expressed by the formula ##STR18## wherein R represents an alkyl group of 1 to 8 carbon atoms, R 2 represents an alkyl group of 1 to 6 carbon atoms, R' represents hydrogen atom or methyl group, n represents an integer of 2 to 20 and A represents a linear, branched or cyclic alkylene group of 5 to 10 carbon atoms.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Examples of the aldehyde used in the present invention are higher aldehydes having a substituent at α-position thereof (see the above items 2) and 4)) such as 2-methylbutyraldehyde, 2-methylvaleraldehyde, 2-methylpentylaldehyde, 2-methylhexylaldehyde, 2-ethylbutylaldehyde, 2-ethylhexylaldehyde, etc., and higher alkenyl aldehydes having a substituent at α-position thereof (see the above items 3) and 5)) such as 2-ethylhexenal, 2-methylpentenal, 2-methylhexenal, etc.
Examples of the alcohol used in the present invention are higher alkanols of 4 to 24 carbon atoms (see R 3 '-OH of the above items 2) and 3)) such as hexanol, 2-ethylbutanol, n-octanol, 2-ethylhexanol, pentanol, cyclohexanol, etc., diols (see HOAOH or ##STR19## of the above items 4) and 5)) such as hexamethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, etc., phenols such as hydroquinone, resorcin, alkylsubstitutes thereof, etc. In the case where the above A has 4 carbon atoms or less (such as ethanediol, 1,4-butanediol, etc.) and in the case of catechol, cyclic acetals are formed as a main component.
Examples of the acidic catalyst used in the present invention are ferric chloride, titanous chloride, titanic chloride, aluminum chloride, zinc chloride, nickel chloride, cobalt chloride, calcium chloride, cation exchange resin, activated clay, molecular sieves, p-toluenesulfonic acid, sulfuric acid, hydrochloric acid, N-hydroxybenzenesulfonamide, etc.
The molar ratio of the aldehyde to the alcohol is 0.5:1 to 10:1, preferably 1:1 to 3:1 in the case of the above items 2) and 3), and the molar ratio of the aldehyde to the diol is 0.05:1 to 10:1, preferably 0.1:1 to 2:1 in the case of the above items 4) and 5).
The quantity of the catalyst used is in the range of 0.01 to 10% by weight, preferably 0.05 to 2% by weight based on the aldehyde. The quantity of N-hydroxybenzenesulfonamide is suitably in the range of 1 to 2%, and that of ferric chloride is suitably in the range of 0.05 to 0.1%, preferably 0.05 to 0.5%. Catalysts soluble in mineral oils are added in a quantity of 0.01 to 5% by weight, preferably 0.05 to 2% by weight. If the quantity is less than the above quantity, there is no catalytic activity, while if it exceeds the above quantity, aldehyde condensation occurs to cause aldehyde loss. Further, it is more preferred to again add the catalyst midway during the reaction.
The reaction temperature of the present invention varies depending on the aldehyde and alcohol used, but anyhow, when formed water is continuously withdrawn in a reflux state of the reaction solution of the aldehyde and the alcohol, the reaction proceeds and the aldehyde and alcohol used are almost insoluble in water so that it is not particularly necessary to use any azeotropic solvent for separating formed water, but it does not matter if the solvent is used. Further, as to the reaction pressure, any one of normal pressure, reduced pressure and elevated pressure may be employed, but usually, normal pressure reaction which is easy in operation may be sufficient.
The effectiveness of the present invention consists in that α,β-unsaturated ethers so far prepared from aldehydes by way of two or three steps could have this time been prepared at only one step, and further in that gas phase reaction at a high temperature of 300° to 800° C. has so far been carried out, but instead, reaction under a mild condition of 200° C. or lower could have this time become possible.
According to the production process of the present invention, it is possible to obtain an unsaturated ether having conjugated double bonds at only one step from an aldehyde.
Further, according to the production process of the present invention, it is possible to obtain a hydroxyalkenyl ether under mild reaction conditions and with a high selectivity by directly acetalizing an alkane diol, a glycol or a hydroquinone in the presence of an acidic catalyst, using an aldehyde having an alkyl substituent at its α-position as a raw material.
Further, according to the production process of the present invention, a hydroxyalkenyl ether having conjugated double bonds, which can be expected as a functional monomer, can be produced from easily commericially available unsaturated aldehyde and diol as raw materials, under a mild condition of a reflux temperature of the aldehyde of 200° C. or lower and with a high selectivity; hence the production process is a commercially excellent process.
According to the production process of the present invention, it is possible to produce alkenyl ethers with a good selectivity.
The present invention will be described in more detail by way of Examples and Comparative examples but it should not be construed to be limited thereto.
EXAMPLE 1
2-Ethylhexylaldehyde (64 parts by weight), hexanol (50 parts by weight) and N-hydroxybenzenesulfonamide (1.1 part by weight) were fed into a four-neck flask, followed by reacting them on heating under reflux with stirring for 4 hours while continuously withdrawing formed water. As a result, the conversion of hexanol was 93.1%, the selectivity of 2-ethylhexenyl hexyl ether was 97.4% and the remainder 2.6% was an acetal.
EXAMPLE 2
2-Ethylbutyraldehyde (50 parts by weight), 2-ethylbutyl alcohol (50 parts by weight) and ferric chloride (0.1 part by weight) were subjected to the same procedure as in Example 1. As a result, the conversion of 2-ethylbutyl alcohol was 93.6%, the selectivity of 2-ethylbutenyl-2-ethylbutyl ether was 67.2% and the remainder 32.8% was an acetal.
EXAMPLE 3
2-Ethylhexylaldehyde (186 parts by weight), lauryl alcohol (185 part by weight) and p-toluenesulfonic acid (0.4 part by weight) were subjected to the same procedure as in Example 1. As a result, the conversion of lauryl alcohol was 97.8%, the selectivity of 2-ethylhexenyl lauryl ether was 100% and no acetal formation was observed.
EXAMPLE 4
2-Ethylhexylaldehyde (154 parts by weight), octanol (128 parts by weight) and aluminum chloride (0.3 part by weight) were subjected to the same procedure as in Example 1. As a result, the conversion of octanol was 88.3%, the selectivity of 2-ethylhexenyl octyl ether was 92.6% and the remainder 7.4% was an acetal.
EXAMPLE 5
2-Ethylhexylaldehyde (154 parts by weight), cyclohexanol (100 parts by weight) and p-toluenesulfonic acid (0.3 part by weight) were subjected to the same procedure as in Example 1. As a result, the conversion of cyclohexanol was 86.8%, the selectivity of 2-ethylhexenyl cyclohexyl ether was 100% and no acetal formation was observed.
COMPARATIVE EXAMPLE 1
When n-hexanal was used in place of 2-ethylbutyraldehyde in Example 2, 100% of an acetal formed and no alkenyl ether formation was observed.
COMPARATIVE EXAMPLE 2
When the same aldehyde and alcohol as in Example 1 and FeCl 3 as a catalyst were cooled with dry ice-acetone and reacted at about -30° C., an acetal formed predominantly.
EXAMPLE 6
2-Methylvaleraldehyde (120 parts by weight), hexanol (100 parts by weight) and p-toluenesulfonic acid (0.2 part by weight) were fed into a four-neck flask, followed by reacting them on heating under reflux with stirring for 4 hours, while continuously withdrawing formed water. As a result, the conversion of hexanol was 84.6%, the selectivity of 2-methylpentenyl hexyl ether was 87.3% and the remainder 12.7% was an acetal.
EXAMPLE 7
2-Methylhexylaldehyde (134 parts by weight), cyclohexanol (100 parts by weight) and zinc chloride (0.2 part by weight) were subjected to the same procedure as in Example 6. As a result, the conversion of cyclohexanol was 85.0%, the selectivity of 2-methylhexenyl cyclohexyl ether was 92.0% and the remainder 8.0% was an acetal.
EXAMPLE 8
2-Methylvaleraldehyde (120 parts by weight), lauryl alcohol (185 parts by weight) and aluminum chloride (0.3 part by weight) were subjected to the same procedure as in Example 6. As a result, the conversion of lauryl alcohol was 97.5%, the selectivity of 2-methylpentenyl lauryl ether was 100% and no acetal formation was observed.
COMPARATIVE EXAMPLE 3
When n-hexanal was used in place of 2-methylvaleraldehyde of Example 6, an acetal was formed in 100% and no alkenyl ether formation was observed.
COMPARATIVE EXAMPLE 4
Example 6 was repeated except that reaction was carried out under cooling with dry ice-acetone at about -30° C. As a result, an acetal formed predominantly.
EXAMPLE 9
2-Ethylhexenal (63 parts by weight), 2-ethylhexanol (64 parts by weight) and p-toluenesulfonic acid (0.1 part by weight) were fed into a four-neck flask, followed by reacting them on heating with stirring under reflux for 5 hours while continuously withdrawing formed water. As a result, the conversion of 2-ethylhexanol was 88.2%, and the selectivity of formation of 1-(2'-ethylhexoxy)-2- ethyl-1,3-hexadiene was 91%.
EXAMPLE 10
2-Methylpentenal (49 parts by weight), hexanol (50 parts by weight) and aluminum chloride (0.1 part by weight) were subjected to the same procedure as in Example 9. As a result, the conversion of hexanol was 91.0% and the selectivity of 1-hexoxy-2-methyl-l,3-pentadiene was 92.5%.
EXAMPLE 11
2-Methylhexenal (56 parts by weight), cyclohexanol (50 parts by weight) and N-hydroxybenzenesulfonamide (1 part by weight) were subjected to the same procedure as in Example 9. As a result, the conversion of cyclohexanol was 94.3% and the selectivity of formation of 1-cyclohexoxy-2-methyl-l,3-hexadiene was 95.6%.
EXAMPLE 12
2-Ethylhexanal (128 parts by weight), hexamethylene glycol (118 parts by weight) and p-toluenesulfonic acid (0.2 part by weight) were fed into a four-neck flask, followed by reacting them on heating with stirring under reflux for 2 hours while continuously withdrawing formed water. As a result, the conversion of hexamethylene glycol was 85% and the selectivity of formation of hexamethylene glycol mono-2-ethylhexenyl ether was 65%.
EXAMPLE 13
2-Ethylhexanal (128 parts by weight), triethylene glycol (150 part by weight) and ferric chloride (0.5 part by weight) were subjected to the same manner as in Example 12. As a result, the conversion of triethylene glycol was 88% and the selectivity of formation of triethylene glycol mono-2-ethylhexenyl ether was 73.5%.
EXAMPLE 14
2-Methylvaleraldehyde (100 parts by weight), dipropylene glycol (134 part by weight) (containing isomers) were subjected to the same manner as in Example 12. As a result, the conversion of dipropylene glycol was 81% and the selectivity of formation of dipropylene glycol mono-2-methylpentenyl ether was 76%.
COMPARATIVE EXAMPLE 5
Hexanal (100 parts by weight), dipropylene glycol (134 parts by weight) (containing isomers) and aluminum chloride (0.4 part by weight) were subjected to the same procedure as in Example 12. As a result, a cyclic acetal formed as a main component and formation of hydroxyalkenyl ether could not be observed.
EXAMPLE 15
2-Ethylhexenal (126 parts by weight), diethylene glycol (106 parts by weight) and ferric chloride (1.2 part by weight) were fed into a four-neck flask, followed by reacting them on heating with stirring under reflux for 5 hours while continuously withdrawing formed water. As a result, the conversion of diethylene glycol was 88% and the selectivity of formation of diethylene glycol mono-2-ethyl-l,3-hexadienyl ether was 77%.
EXAMPLE 16
2-Ethylhexenal (128 parts by weight), triethylene glycol (150 parts by weight) and aluminum chloride (1.2 part by weight) were subjected to the same procedure as in Example 15. As a result, the conversion of triethylene glycol was 86% and the selectivity of formation of triethylene glycol mono-2-ethyl-l,3-hexadienyl ether was 80%. | A one-step process for producing an alkenyl ether in only one step and under mild conditions by reacting an aldehyde of the formula ##STR1## with an alcohol of the formula
R.sup.3 --OH
in the presence of an acidic catalyst in liquid phase, and recovering as the reaction product an alkenyl ether of the formula ##STR2## wherein R 1 is a 2-8 C alkyl or R--CH 2 --CH═ wherein R is a 1-8 C alkyl group,
R 2 is a 1-6 C alkyl,
R 3 is a linear or branched 6-12 C alkyl, a cyclohexyl, a hydroxyhexamethylenyl or ##STR3## wherein R' is H and n is 2 or 3, R 4 is hydrogen or R--CH 2 --CH═ wherein R is a 1-8 C alkyl group, and
R 5 is a 2-8 C alkyl or R--CH═CH-- wherein R is a 1-8 C alkyl. | 2 |
RELATED APPLICATION
[0001] This application is a Continuation of U.S. application Ser. No. 13/827,270, filed Mar. 14, 2013, which claims priority to a Continuation-In-Part application Ser. No. 13/645,976, filed Oct. 5, 2012 and entitled “Flexible Corner Trim Product”, which is a Continuation-In-Part of application Ser. No. 13/632,447, filed Oct. 1, 2012 and entitled “Flexible Corner Trim Product”, which is a Continuation-In-Part of application Ser. No. 12/843,582, filed Jul. 26, 2010, and entitled “Flexible Corner Trim Product, which claims the benefit of U.S. Provisional Application No. 61/228,757 filed Jul. 27, 2009, entitled “Flexible Caulking Product”, which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to building products, and more particularly to flexible corner trim material for new construction, remodeling, kitchen and bathroom applications.
BACKGROUND
[0003] As society becomes more and more tethered to electronic devices, wire and cable management is a challenge that we are increasingly facing. It is especially difficult when trying to achieve timeless, uncluttered design. One solution is to fully integrate wires into a design or construction elements, which requires significant planning and financial resources. For those who can't make permanent changes to homes, apartments, or office buildings, there are some options to keep surfaces wire free. In some instances, plastic zip ties and eye hooks are used to affix cables and wires to undersides of surfaces. However, available products to solve the mess and disorganization of wires and cables have not revealed suitable options.
SUMMARY OF THE INVENTION
[0004] The present invention provides a efficient means for concealing wires or fiber cables in a trim piece that can be easily secured to a surface. In one embodiment, the invention includes a trim piece for receiving and concealing a fiber wire. The trim piece includes an elongated unitary structure of indeterminate length which when viewed in cross section, includes a body presenting a first wing portion and an opposed second wing portion and an intervening decorative surface on an outwardly visible face comprising a flap extending between the first wing portion and the second wing portion. The first wing portion and the second wing portion extend outwardly away from the body and terminate in a substantially knife edge. A channel is disposed in the body, whereby the channel is capable of receiving a fiber wire. The body includes an aperture and a seam for providing access to the aperture, whereby the seam is formed by an overlap between the flap and an inner flap. The invention also includes an adhesive portion. The adhesive portion extends at least partially over an inward face of the body. In addition, the trim piece is formed from a flexible polymer material having a flexible resiliency such that the first wing portion and the second wing portion are each deformed generally outwardly by contact with one of the two structures and wherein the first wing portion and the second wing portion establish a generally sealing relationship with the two surfaces and wherein the adhesive portion adheres to the two surfaces and establishes an equilibrium with the flexible resiliency of the polymer material such that the first outward portion and the second outward portion are each in deformed sealing contact with the first structure and the second structure.
[0005] In another embodiment the present invention provides a simple finished corner trim product without requiring the skill level for application that caulk does or the accessibility of a caulk gun. The present invention also provides a product that will not expire over time and/or become unusable do to curing in partial tubes.
[0006] The present invention includes a corner trim material composed of a single or multiple density extruded PVC, TPO, bio based polymer, EcoFlex, Elvax (or similar) product. The extrusion is defined by a cross section of between ⅛″ and 4″. In a preferred embodiment, the extrusion includes a 25-160 degree wedge.
[0007] In an alternative embodiment, the extrusion includes a single “leg” with a variable wedge shape at the bottom with a flat finished “cap” that has a variable proportioned “wing” on each side. The “wings” are an integral part of the trim as it is more flexible than the top cap and will contour itself to the irregularities of the surface being adhered to. The wedge and leg has 3M VHB Tape (or similar adhesive product), manufactured by 3M Company of St. Paul, Minn., and applied to one or both sides of the wedge or leg to adhere the product to any surface and also to provide a tight bond and seal.
[0008] In another embodiment, the invention includes a trim piece for sealing a work surface. The trim piece has a body that includes a first side, a second side, and a span disposed between the first side and the second side. The first side and the second side are joined at a junction. A topcap is affixed to the span of the body. The topcap includes a left side and a right side and adhesive is bonded to the first side of the body.
[0009] In yet another embodiment, the invention includes a trim piece for sealing a work surface including a body having a first side, a second side, and a span disposed between the first side and the second side. The first side and the second side are joined at a junction defining an angle between the first side and the second side of between 80 degrees and 100 degrees. A topcap is affixed to the span of the body. The topcap includes a left side having a first wing and a right side having a second wing. An adhesive is bonded to the first side of the body and an aperture is disposed within the body.
[0010] In still another embodiment, the invention includes method for sealing a void in a work surface. The method includes the step of obtaining trim piece having a body including a first side, a second side, and a span disposed between the first side and the second side. The first side and the second side are joined at a junction defining an angle between the first side and the second side of between 80 degrees and 100 degrees. The topcap is affixed to the span of the body, wherein the topcap includes a left side having a first wing and a right side having a second wing. Adhesive is bonded to the first side of the body, wherein the adhesive includes a removable cover. An aperture is disposed within the body. The method further includes the step of removing the removable cover from the adhesive and placing the adhesive in contact with the work surface such that the junction of the trim piece is disposed within the void.
[0011] In yet another embodiment, the invention includes a trim piece for sealing a joint in a work surface, the joint being formed where two structures meet at an inside angle. The trim piece includes an elongated unitary structure of indeterminate length which when viewed in cross section includes a body having a generally triangular section portion and presenting a first wing portion and an opposed second wing portion and an intervening decorative surface on an outwardly visible face extending between the first wing portion and the second wing portion. The first wing portion and the second wing portion extend outwardly away from the generally triangular section portion and terminate in a substantially knife edge. A channel is disposed in the generally triangular section portion. An adhesive portion extends at least partially over two inward faces of the generally triangular section. The adhesive portion presents a first adhesive face and a second adhesive face. A first imaginary extension of the first adhesive face intersects the first wing portion and a second imaginary extension of the second adhesive face intersects the second wing portion such that a first outward portion of the first wing portion extends beyond the first imaginary extension when the first wing portion is undeformed. A second outward portion of the second wing portion extends beyond the second imaginary extension when the second wing portion is undeformed and when the adhesive is uncompressed. The trim piece is formed from a flexible polymer material having a flexible resiliency such that the first wing portion and the second wing portion are each deformed generally outwardly by contact with one of the two structures and wherein the first wing portion and the second wing portion establish a generally sealing relationship with the two surfaces. Additionally, the adhesive portion adheres to the two surfaces and establishes an equilibrium with the flexible resiliency of the polymer material such that the first outward portion and the second outward portion are each in deformed sealing contact with the first structure and the second structure.
[0012] In yet another embodiment, the invention includes a trim piece for sealing a joint in a work surface. The trim piece includes an elongated unitary structure of indeterminate length which when viewed in cross section includes a body having a generally triangular section portion and presenting a first wing portion and an opposed second wing portion and an intervening decorative surface on an outwardly visible face extending between the first wing portion and the second wing portion. The first wing portion and the second wing portion extend outwardly away from the body and terminates in a substantially knife edge. A channel is disposed in the body. An adhesive portion extends at least partially over two inward faces of the body. The adhesive portion presents a first adhesive face and a second adhesive face. A first imaginary extension of the first adhesive face intersects the first wing portion and a second imaginary extension of the second adhesive face intersects the second wing portion such that a first outward portion of the first wing portion extends beyond the first imaginary extension when the first wing portion is undeformed. A second outward portion of the second wing portion extends beyond the second imaginary extension when the second wing portion is undeformed and when the adhesive is uncompressed. The trim piece is formed from a flexible polymer material having a flexible resiliency such that the first wing portion and the second wing portion are each deformed generally outwardly by contact with one of the two structures and wherein the first wing portion and the second wing portion establish a generally sealing relationship with the two surfaces. Additionally, the adhesive portion adheres to the two surfaces and establishes an equilibrium with the flexible resiliency of the polymer material such that the first outward portion and the second outward portion are each in deformed sealing contact with the first structure and the second structure.
[0013] In yet another embodiment, the invention includes a trim piece for sealing a joint in a work surface. The trim piece includes an elongated unitary structure of indeterminate length which when viewed in cross section includes a body presenting a first wing portion and an opposed second wing portion and an intervening decorative surface on an outwardly visible face extending between the first wing portion and the second wing portion. The first wing portion and the second wing portion extend outwardly away from the body and terminating in a substantially knife edge. A communications cable is disposed in the body. An adhesive portion extends at least partially over two inward faces of the body. The adhesive portion presents a first adhesive face and a second adhesive face. A first imaginary extension of the first adhesive face intersects the first wing portion and a second imaginary extension of the second adhesive face intersects the second wing portion such that a first outward portion of the first wing portion extends beyond the first imaginary extension when the first wing portion is undeformed. A second outward portion of the second wing portion extends beyond the second imaginary extension when the second wing portion is undeformed and when the adhesive is uncompressed. The trim piece is formed from a flexible polymer material having a flexible resiliency such that the first wing portion and the second wing portion are each deformed generally outwardly by contact with one of the two structures and wherein the first wing portion and the second wing portion establish a generally sealing relationship with the two surfaces. Additionally, the adhesive portion adheres to the two surfaces and establishes an equilibrium with the flexible resiliency of the polymer material such that the first outward portion and the second outward portion are each in deformed sealing contact with the first structure and the second structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a cross-sectional view of the trim piece in accordance with the present invention.
[0015] FIG. 2 is a cross-sectional view of an alternative embodiment of the trim piece in accordance with the present invention.
[0016] FIG. 3 is a cross-sectional view of an alternative embodiment of the trim piece in accordance with the present invention.
[0017] FIG. 4 is a cross-sectional side view of an alternative embodiment of the trim piece in accordance with the present invention.
[0018] FIG. 5 is a cross-sectional side view of a leg in accordance with the present invention.
[0019] FIG. 6 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0020] FIG. 7 is a cross sectional view of another embodiment of a trim piece according to the invention including a coextruded adhesive portion.
[0021] FIG. 8 is a cross sectional view of another embodiment of a trim piece according to the invention including a coextruded adhesive portion.
[0022] FIG. 9 is a cross sectional view of another embodiment of a trim piece according to the invention with flexed wing tips.
[0023] FIG. 10 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0024] FIG. 11 is a cross sectional view of a trim piece according to another embodiment of the invention;
[0025] FIG. 12 is a cross sectional view of a trim piece according to another embodiment of the invention, depicting limits of adhesive depth to provide proper sealing of the wing at contact.
[0026] FIG. 13 is a cross sectional view of a testing apparatus according to another embodiment of the invention; and
[0027] FIG. 14 is a longitudinal; sectional view of the testing apparatus of FIG. 13 .
[0028] FIG. 15 is a graph and legend depicting results of a wing flex test according to an embodiment of the invention.
[0029] FIG. 16 is a graph and legend depicting results of a surface bonding test according to an embodiment of the invention.
[0030] FIG. 17 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0031] FIG. 18 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0032] FIG. 19 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0033] FIG. 20 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0034] FIG. 21 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0035] FIG. 22 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0036] FIG. 23 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0037] FIG. 24 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0038] FIG. 25 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0039] FIG. 26 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0040] FIG. 27 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0041] FIG. 28 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0042] FIG. 29 is a cross sectional view of another embodiment of a trim piece according to the invention.
[0043] FIG. 30 is a cross sectional view of another embodiment of a trim piece according to the invention.
DETAILED DESCRIPTION
[0044] With reference to FIG. 1 , a cross-sectional view of trim piece 10 is shown. It should be understood that trim piece 10 is not-specific in length. Rather, it is preferably fabricated during an extrusion process and can be trimmed to a length that is suitable for a specific application. As a fundamental matter, it should be understood that the trim piece is flexible. As such, it can be manipulated to conform to a desired surface.
[0045] Trim piece 10 is defined by body 12 , topcap 14 and adhesive 16 . In a preferred embodiment, body 12 has a triangular cross-sectional shape that includes aperture 18 . Aperture 18 serves as a cooling tunnel that is useful in forming trip piece 10 .
[0046] Body 12 includes first side 20 and second side 22 . In a preferred embodiment, first side 20 and second side 22 are substantially equal in length. First side 20 and second side 22 intersect at junction 24 . In a preferred embodiment, junction 24 has a substantially flat configuration to provide clearance when trim piece 10 is applied to a surface. Opposite body 12 from junction 24 is span 26 . Span 26 extends from first side 20 to second side 22 . In a preferred embodiment, the angle between first side 20 and second side 22 at junction 24 is between 80 degrees and 100 degrees, preferably 90 degrees.
[0047] Span 26 includes an interior side 28 and an exterior side 30 . Topcap 14 is disposed about the exterior side 30 of span 26 , and provides an aesthetically pleasing surface that serves as the visible portion of trim piece 10 .
[0048] First side 20 includes an interior side 32 and an exterior side 34 . Adhesive 16 is bonded to exterior side 34 and serves to fasten trim piece 10 to a work surface. It should be appreciated that adhesive 16 may be bonded to exterior side 34 by a wide array of mechanical or chemical means while remaining within the scope of the invention.
[0049] Topcap 14 includes a left side 36 and a right side 38 . Wings 40 and 42 are disposed on left side 36 and right side 38 respectively. Wings 40 and 42 include a tapered configuration that provides a smooth surface that contacts the work surface to provide a smooth, even appearance as trim piece 10 abuts a work surface.
[0050] FIG. 2 shows a cross-sectional configuration of an alternative embodiment of trim piece 10 . In this embodiment, the angle between first side 20 and second side 22 at junction 24 is between 150 degrees and 170 degrees, preferably 160 degrees.
[0051] FIG. 3 shows a cross-sectional configuration of an alternative embodiment of trim piece 10 . In this embodiment, the angle between first side 20 and second side 22 at junction 24 is between 15 degrees and 35 degrees, preferably 25 degrees.
[0052] The angled trim end or wings 40 and 42 will be proportionally variable in length and will terminate in a point that is approximately 10 degrees off of the line of the horizontal topcap 14 . This angled point or wing 40 and 42 ensures the trim piece 10 will follow the irregularities of the surface being adhered to, thus creating as tight a seal as possible.
[0053] Each of the first side 20 and second side 22 of the trim piece 10 may include adhesive 16 depending on the application. In some embodiments, adhesive 16 may be disposed on both first side 20 and second side 22 . In a preferred embodiment, adhesive 16 is only disposed on first side 20 , as shown in FIG. 1 . In a preferred embodiment, adhesive 16 is a 3M VHB (Very High Bond) tape manufactured by 3M Company of St. Paul, Minn. or similar product. The width and depth of the tape will depend on the extruded size of the respective first side 20 and second side 22 . In a preferred embodiment, adhesive 16 will range from between ⅛″ in width up to 3″ in width. The thickness of the adhesive 16 will range from 0.025 mm up to ⅛″.
[0054] With reference to FIG. 5 , the body 12 will have adhesive 16 on one of both sides tape depending on the application. The tape will be a 3M VHB (Very High Bond) tape manufactured by 3M Company of St. Paul, Minn. or similar product. The width and depth of the tape will depend on the extruded size of the Invention and will range from ⅛″ in width up to 3″ in width. The thickness of the tape will range from 0.025 mm up to ⅛″. The adhesive 16 may be mechanically or chemically bonded to the first side 20 , second side 22 , or the body 12 of the trim piece 10 following the extrusion process. In a preferred embodiment, adhesive 16 includes a removable protective cover for the end user to remove during the installation process. The protective cover can comprise a peel-off strip. In another preferred embodiment, the protective cover of adhesive 16 includes an extended section of cover that will extend beyond the extruded end of the trim piece 10 to facilitate on site removal of the cover prior to application. This cover extension is between ⅛″ and 1.5″ in length and will have the adhesive 16 removed.
[0055] With reference to FIGS. 1-3 , the body 12 of trim piece 10 will now be discussed. Junction 24 of the trim piece 10 preferably has a small flat “void” area which will allow for imperfections in the corner material that the trim piece 10 is applied to. This flat void will be variable in width depending on the extruded size of the invention. In a preferred embodiment, the actual size will range from 1/32″ on up to ½″.
[0056] The body 12 of trim piece 10 shall be an extrusion of PVC, TPO, Bio based polymer, EcoFlex, Elvax (or similar) product of the same density than the topcap 14 . Both the topcap 14 and the body 12 may be a single or multiple durometer extrusion which will fuse both pieces together. The aperture 18 is hollow to aid in the cooling of the body 12 during the extrusion process. The aperture 18 will also aid the trim piece 10 in being applied to tight radius inner and outer corners and still maintain the ability of the wings 40 and 42 to make proper contact with the subsurface.
[0057] The configuration of topcap 14 will now be discussed. The top cap is comprised of PVC, TPO, Bio based polymer, EcoFlex, Elvax (or similar) material in variable widths depending on the final extrusion dimension and will range, in a preferred embodiment, from ¼″ on up to 4″. The depth of the topcap 14 will also depend on the final extrusion dimension and application. The length of the topcap 14 is dependent upon the overall length of the final trim piece 10 . This piece will be a part of the single or multiple durometer extrusion and may be extruded with a denser PVC, TPO, Bio based polymer, EcoFlex, Elvax (or similar) material. The topcap 14 can be extruded in any color and also can be finished with a film of any color or pattern which would be applied during the extrusion process along with custom printed logos and designs for a particular vendor. In addition, the topcap 14 may also be produced with a porous finished film that can be later stained to match the adjacent material it is being applied to.
[0058] With reference to FIG. 4 , additional details of trim piece 10 will now be discussed. FIG. 4 shows a side elevation view showing the angled edge of the topcap. This view shows the 3M VHB (Very High Bond) tape manufactured by 3M Company of St. Paul, Minn. or similar product running the entire length of the trim piece 10 . The length and width will vary depending on the final size of the extrusion and the overall length of the extrusion. The bottom tip of the junction 24 is also shown.
[0059] Referring to FIGS. 6-12 and in particular to FIG. 6 , trim piece 110 according to another embodiment of the invention, generally includes body 112 and top cap 114 . Body 112 generally presents rounded intersection 116 at the juncture of first side 118 and second side 120 . Body 112 and top cap 114 extend outwardly to present first wing tip 122 and second wing tip 124 . First wing tip 122 meets body 112 and presents radius 126 at the intersection of side 118 and wing tip 122 . Second wing tip 124 meets body 112 and presents radius 128 at the intersection of side 120 and wing tip 124 . First wing tip 122 presents flat decorative surface 130 where it joins top cap 114 . Second wing tip 124 presents flat decorative surface 132 where it joins top cap 114 . Top cap 114 presents decorative surface 134 and decorative surface 136 thereon.
[0060] Referring particularly to FIG. 9 , trim piece 110 includes, in addition to the structures previously described, adhesive 138 and adhesive 140 .
[0061] Adhesive 138 further presents first adhesive limit 142 and second adhesive limit 144 . Adhesive 140 present's third adhesive limit 146 and fourth adhesive limit 148 .
[0062] Referring to FIG. 11 and FIG. 9 , adhesive 138 further presents imaginary line 150 showing limits of adhesive 138 depth. Adhesive 140 further present's imaginary line 152 showing limits of adhesive 140 depth.
[0063] Referring now particularly to FIG. 12 , first wing tip 122 presents first wing length 154 . Second wing tip 124 presents second wing length 156 .
[0064] Referring particularly to FIG. 9 , imaginary lines 158 and 160 depicting limits of a depth of adhesive 138 , 140 at an intersection with radius 126 and 128 to provide proper sealing of wings 122 and 124 at contact point 160 and 162 after flex of wings 122 and 124 upon application. Proper contact points 162 and 164 indicate where wings 122 and 124 contact a substrate to ensure a tight seal relative to depth of adhesive 138 and 140 and length of wings in relation to imaginary lines 154 and 156 .
[0065] Referring particularly to FIG. 7 , another embodiment of trim piece 110 is depicted. According to the depicted embodiment, beginning at adhesive limit 166 , adhesive coextrusion 168 extends to adhesive limit 170 and includes adhesive coextrusion portion 172 . Adhesive coextrusion 168 , 172 , approaches rounded intersection 116 and it extends from first side 118 to second side 120 . Adhesive coextrusion 168 , 172 has a generally V-shaped structure and is coextruded along with trim piece 110 . The use of adhesive coextrusion 168 , 172 , simplifies the manufacturing process by eliminating the necessity to separately assemble adhesive 138 , 140 to trim piece 110 .
[0066] Referring particularly to FIG. 8 , another example embodiment of the trim piece 110 is depicted. According to the depicted embodiment, trim piece 110 includes body 112 having top cap 114 and extrusion nipple 174 extending downwardly from top cap 114 to support adhesive 138 and 140 . In the depicted embodiment, body 112 present's first nipple termination 178 and second nipple termination 178 where top cap 114 is integrally joined to extrusion nipple 174 . In the embodiment of trim piece 110 depicted in FIG. 8 , adhesive portions 138 and 140 coextruded along with body 112 .
[0067] FIG. 17 shows trim piece 210 according to another embodiment of the invention. Trim piece 210 generally includes body 212 and top cap 214 . Body 212 generally presents rounded intersection at the junction of first side 218 and second side 220 . Body 212 and top cap 214 extend outwardly to present first wing tip 222 and second wing tip 224 . First wing tip 222 meets body 212 and presents radius 226 at the intersection of side 218 and wing tip 222 . Second wing tip 224 meets body 212 and presents radius 228 at the intersection of side 220 and wing tip 224 . First wing tip 222 presents flat decorative surface where it joins top cap 214 . Second wing tip 224 presents a flat decorative surface where it joins top cap 214 . Top cap 214 presents decorative surface 234 and decorative surface 236 thereon.
[0068] Referring particularly to FIG. 17 , trim piece 210 includes, in addition to the structures previously described, adhesive 238 and adhesive 240 .
[0069] Adhesive 238 further presents first adhesive limit 242 and second adhesive limit 244 . Adhesive 240 present's third adhesive limit 246 and fourth adhesive limit 248 .
[0070] Referring to FIG. 17 , adhesive 238 further presents imaginary line 258 showing limits of adhesive 238 depth. Adhesive 240 further present's imaginary line 260 showing limits of adhesive 240 depth.
[0071] Referring now particularly to FIG. 17 , imaginary lines 258 and 260 depicting limits of a depth of adhesive 238 , 240 at an intersection with radius 226 and 228 to provide proper sealing of wings 222 and 224 after flex of wings 222 and 224 upon application. Proper contact points 262 and 264 indicate where wings 222 and 224 contact a substrate to ensure a tight seal relative to depth of adhesive 238 and 240 and length of wings in relation to imaginary lines 258 and 260 .
[0072] The embodiment shown in FIG. 17 includes channel 276 . Channel 276 is defined by an elongated channel running throughout body 212 . In one embodiment, channel 276 is further defined by lips 278 and 280 that are separated by opening 282 . In a preferred embodiment, channel 276 is configured to receive electrical wire or optical fiber. In another preferred embodiment, electrical wire or optical fiber may be positioned into channel 276 and lips 278 and 280 retain the electrical wire or optical fiber in channel 276 .
[0073] Referring to FIGS. 18-20 , an alternative embodiment of trim piece 210 is depicted. Trim piece 210 generally includes body 212 that extends outwardly to present first wing tip 222 and second wing tip 224 . In addition to the structures previously described, adhesive 314 is also included.
[0074] With reference to FIG. 18 , communications cable 274 is disposed inside body 212 . Communications cable 274 may be a fiber optic wire, electrical wire, or any other cable that is capable of transferring a signal. In a preferred embodiment, body 212 is molded around communications cable 274 during fabrication. Trim piece 210 is used to conceal communications cable by sticking to a surface when adhesive 314 is removed from body 212 . This enables a user to install communications cable 274 without the need to penetrate a wall, floor or ceiling.
[0075] Referring to FIG. 19 , body 212 includes cavity 276 . Cavity 276 is capable of receiving a communications cable. During installation, adhesive 314 is separated to expose cavity 276 . An installer will then insert communications cable into cavity 276 and stick body 212 onto a surface thereby concealing the communications cable from view.
[0076] With reference to FIG. 20 , a preferred embodiment of trim piece 210 is shown. In this embodiment, adhesive 314 is separated at a point adjacent to cavity 274 . This enables an installer to ready trim piece 210 by inserting communications cable into cavity 276 of trim piece 210 . When the installer is ready to place the trim piece 210 with the communications cable disposed in cavity 276 , the installer can then remove the adhesive 314 on both sides of cavity 276 .
[0077] With reference to FIG. 21 , a preferred embodiment of trim piece 310 is shown. Trip piece 310 is defined by body 312 and further includes first side 318 and second side 320 . Side 318 and 320 intersect at intersection 316 that provides a clearance for trim piece 310 . Trim piece 310 further includes wing tip 322 and second wing tip 324 . Radius 326 is formed by the union of side 318 and wing tip 322 , thereby providing a radius that allows for flexing of wing tip 322 against a surface. Radius 328 is formed by a union of side 320 and wing tip 324 , thereby providing a radius that allows for flexing of wing tip 324 against a surface. Trim piece 310 also includes wing tip 330 and 332 . Trim piece 310 is further defined by decorative surface 334 and 336 . Adhesive 338 is disposed on first side 318 . Adhesive 340 is disposed on second side 320 . Adhesive 338 and adhesive 340 form approximately a 90-degree angle that can nest with a corner such as where two walls meet, or where a floor and a wall meets, or where a ceiling and a wall meets. Adhesive 338 terminates at 342 where radius 326 for wing 322 begins. Similarly, the other side of adhesive 338 terminates at 344 to provide sufficient clearance for a corner of a surface. Adhesive 340 terminates at limit 346 to allow for the beginning of radius 328 for wing 332 . Likewise, the other side of adhesive 340 terminates at 348 to allow for sufficient clearance for a corner of a surface.
[0078] Slit 424 is formed in body 312 of trim piece 310 . Slit 424 is defined by left side 420 and right side 422 and aperture 376 . Aperture 376 is configured to all for insertion of fiber wire into aperture 376 to generally conceal fiber wire from view. Aperture 376 may accommodate one or more lengths of fiber wire while remaining within the scope of the invention. In addition, the cross sectional profile of aperture 376 is oval on FIG. 21 . However, the cross-sectional profile of aperture 376 may be square, rectangular, triangular, or the shape of other known regular or irregular polygons while remaining within the scope of the invention.
[0079] With reference to FIG. 22 , a preferred embodiment of trim piece 310 is shown. Trim piece 310 includes body 312 , wing tip 322 , second wing tip 324 , top cap forming a decorative surface 334 . Body 312 includes flap 426 for access to aperture 376 . In operation, flap 426 may be peeled back to allow for insertion of fiber wire into aperture 376 . Trim piece 310 also includes adhesive 338 to allow trim piece 310 to be affixed to a surface. Adhesive 338 terminates at limit 416 and 418 to allow wing tip 322 and wing tip 324 to contact a surface, thereby forming a smooth, finished appearance.
[0080] With reference to FIG. 23 , an alternate embodiment of trim piece 310 is shown. Trim piece 310 includes body 312 , wing tip 322 , second wing tip 324 , top cap forming a decorative surface 334 . Body 312 includes aperture 376 . Aperture 376 is configured to receive one or more fiber cables. In operation, fiber cables are inserted into aperture 376 through slit 424 . Slit 424 is defined by left side 420 and right side 422 . Trim piece 310 also includes adhesive 338 to allow trim piece 310 to be affixed to a surface. Adhesive 338 terminates at limit 416 and 418 to allow wing tip 322 and wing tip 324 to contact a surface, thereby forming a smooth, finished appearance.
[0081] With reference to FIG. 24 , a an alternate embodiment of trim piece 310 is shown. Trim piece 310 includes body 312 , wing tip 322 , second wing tip 324 , top cap forming a decorative surface 334 . Body 312 includes flap 426 for access to aperture 376 . In operation, flap 426 may be peeled back to allow for insertion of fiber wire into aperture 376 . In a preferred embodiment, flap 426 terminates in a S-shaped profile 428 to facilitate the insertion of fiber and wire into the aperture 376 . Side 432 is configured to mate with profile 428 to effectively lock fiber or wire into aperture 376 . In this embodiment, the opening 424 between profile 428 and side 432 is very small such that it forms a very tight seam in the extrusion that must be opened with a small pick or tool for access. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam. Trim piece 310 also includes adhesive 338 to allow trim piece 310 to be affixed to a surface. Adhesive 338 terminates at limit 416 and 418 to allow wing tip 322 and wing tip 324 to contact a surface, thereby forming a smooth, finished appearance.
[0082] With reference to FIG. 25 , another alternate embodiment of trim piece 310 is shown. Trim piece 310 includes body 312 , wing tip 322 , second wing tip 324 , top cap forming a decorative surface 334 . Body 312 includes flap 426 for access to aperture 376 . In operation, flap 426 may be peeled back to allow for insertion of fiber wire into aperture 376 . In a preferred embodiment, flap 426 terminates in an edge including two 90 degree angles 428 to facilitate the insertion of fiber and wire into the aperture 376 . Side 432 is configured to mate with profile 428 to effectively lock fiber or wire into aperture 376 . In this embodiment, the opening 424 between profile 428 and side 432 is very small such that it forms a very tight seam in the extrusion that must be opened with a small pick or tool for access. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam. Trim piece 310 also includes adhesive 338 to allow trim piece 310 to be affixed to a surface. Adhesive 338 terminates at limit 416 and 418 to allow wing tip 322 and wing tip 324 to contact a surface, thereby forming a smooth, finished appearance.
[0083] In operation, the profile with the oval aperture 376 allows for a user to pull back flap 426 for easy access to install or remove one or multiple fibers in aperture 376 . The trim piece trim piece 310 can then be installed in areas like hallways with multiple fibers already inside trim piece 310 . At doorways, a user can pull down the flap 426 to remove one fiber to be run into an office or residential unit. Accordingly, easy access to the fibers from the side opposite the adhesive 338 is desired.
[0084] With reference to FIG. 26 , another alternate embodiment of trim piece 410 is shown. Trim piece 410 includes body 412 , wing tip 422 , second wing tip 424 , and top cap 414 forming a decorative surface 534 . Body 412 includes flap 526 for access to aperture 476 . In operation, flap 526 may be peeled back to allow for insertion of fiber wire into aperture 476 . In a preferred embodiment, flap 526 overlaps with inner flap 536 such that the surface of flap 526 rests against the surface of inner flap 536 at union 538 . During insertion of a fiber wire into aperture 476 , a user can peel flap 526 away from inner flap 536 , thereby creating a self closing seam 524 through which a wire can be inserted into aperture 476 through. Flap interface 532 is comprised of the inner flap 536 and flap 534 that meets to create self closing seam 524 . Adhesive 438 is disposed on the bottom surface of trim piece 410 to secure trim piece to a surface. Adhesive 438 terminates in limit 516 and limit 518 to allow wing tip 422 and 424 to contact a surface, thereby forming a smooth, finished appearance. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam.
[0085] With reference to FIG. 27 , another alternate embodiment of trim piece 410 is shown. This embodiment is similar to the embodiment shown in FIG. 26 , except it incorporates a “locking” hook to engage the outer flap. Trim piece 410 includes body 412 , wing tip 422 , second wing tip 424 , and top cap 414 forming a decorative surface 534 . Body 412 includes flap 526 for access to aperture 476 . In operation, flap 526 may be peeled back to allow for insertion of fiber wire into aperture 476 . In a preferred embodiment, flap 526 overlaps with inner flap 536 such that the surface of flap 526 rests against the surface of inner flap 536 at union 538 . During insertion of a fiber wire into aperture 476 , a user can peel flap 526 away from inner flap 536 , thereby creating a self closing seam 524 through which a wire can be inserted into aperture 476 through. Flap interface 532 is comprised of the inner flap 536 and flap 534 that meet to create self closing seam 524 . In addition, trim piece 410 includes an end 540 of flap 526 . End 540 forms a mechanical interface with lock 542 to secure flap 526 near inner flap 536 . It should be appreciated that the configuration of end 540 and lock 542 can take a wide variety of forms to create the desired mechanical interface, while remaining within the scope of the invention. Adhesive 438 is disposed on the bottom surface of trim piece 410 to secure trim piece to a surface. Adhesive 438 terminates in limit 516 and limit 518 to allow wing tip 422 and 424 to contact a surface, thereby forming a smooth, finished appearance. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam.
[0086] With reference to FIG. 28 , another alternate embodiment of trim piece 410 is shown. This embodiment is similar to the embodiment shown in FIG. 26 , except it incorporates an adhesive 544 between flap 526 and inner flap 536 to secure flap 526 to inner flap 536 . Trim piece 410 includes body 412 , wing tip 422 , second wing tip 424 , and top cap 414 forming a decorative surface 534 . Body 412 includes flap 526 for access to aperture 476 . In operation, flap 526 may be peeled back to allow for insertion of fiber wire into aperture 476 . In a preferred embodiment, flap 526 overlaps with inner flap 536 such that the surface of flap 526 rests against the surface of inner flap 536 at union 538 . During insertion of a fiber wire into aperture 476 , a user can peel flap 526 away from inner flap 536 , thereby creating a self closing seam 524 through which a wire can be inserted into aperture 476 through. Adhesive 544 may be permanently sealable, or re-sealable, depending on the desired application. Flap interface 532 is comprised of the inner flap 536 and flap 534 that meet to create self closing seam 524 . In addition, trim piece 410 includes an end 540 of flap 526 . End 540 forms a mechanical interface with lock 542 to secure flap 526 near inner flap 536 . It should be appreciated that the configuration of end 540 and lock 542 can take a wide variety of forms to create the desired mechanical interface, while remaining within the scope of the invention. Adhesive 438 is disposed on the bottom surface of trim piece 410 to secure trim piece to a surface. Adhesive 438 terminates in limit 516 and limit 518 to allow wing tip 422 and 424 to contact a surface, thereby forming a smooth, finished appearance. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam.
[0087] With reference to FIG. 29 , another alternate embodiment of trim piece 410 is shown. This embodiment is similar to the embodiment shown in FIG. 26 , except it incorporates an instant or UV cure liquid adhesive 548 between flap 526 and inner flap 536 to secure flap 526 to inner flap 536 . Trim piece 410 includes body 412 , wing tip 422 , second wing tip 424 , and top cap 414 forming a decorative surface 534 . Body 412 includes flap 526 for access to aperture 476 . In operation, flap 526 may be peeled back to allow for insertion of fiber wire into aperture 476 . In a preferred embodiment, flap 526 overlaps with inner flap 536 such that the surface of flap 526 rests against the surface of inner flap 536 at union 538 . During insertion of a fiber wire into aperture 476 , a user can peel flap 526 away from inner flap 536 , thereby creating a self closing seam 524 through which a wire can be inserted into aperture 476 through. Flap interface 532 is comprised of the inner flap 536 and flap 534 that meet to create self closing seam 524 . In addition, trim piece 410 includes an end 540 of flap 526 . End 540 forms a mechanical interface with lock 542 to secure flap 526 near inner flap 536 . It should be appreciated that the configuration of end 540 and lock 542 can take a wide variety of forms to create the desired mechanical interface, while remaining within the scope of the invention. Adhesive 438 is disposed on the bottom surface of trim piece 410 to secure trim piece to a surface. Adhesive 438 terminates in limit 516 and limit 518 to allow wing tip 422 and 424 to contact a surface, thereby forming a smooth, finished appearance. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam.
[0088] With reference to FIG. 30 , another alternate embodiment of trim piece 410 is shown. This embodiment is similar to the embodiment shown in FIG. 26 , except it incorporates a hook and loop fastener 546 between flap 526 and inner flap 536 to secure flap 526 to inner flap 536 . Trim piece 410 includes body 412 , wing tip 422 , second wing tip 424 , and top cap 414 forming a decorative surface 534 . Body 412 includes flap 526 for access to aperture 476 . In operation, flap 526 may be peeled back to allow for insertion of fiber wire into aperture 476 . In a preferred embodiment, flap 526 overlaps with inner flap 536 such that the surface of flap 526 rests against the surface of inner flap 536 at union 538 . During insertion of a fiber wire into aperture 476 , a user can peel flap 526 away from inner flap 536 , thereby creating a self closing seam 524 through which a wire can be inserted into aperture 476 through. Flap interface 532 is comprised of the inner flap 536 and flap 534 that meet to create self closing seam 524 . In addition, trim piece 410 includes an end 540 of flap 526 . End 540 forms a mechanical interface with lock 542 to secure flap 526 near inner flap 536 . It should be appreciated that the configuration of end 540 and lock 542 can take a wide variety of forms to create the desired mechanical interface, while remaining within the scope of the invention. Adhesive 438 is disposed on the bottom surface of trim piece 410 to secure trim piece to a surface. Adhesive 438 terminates in limit 516 and limit 518 to allow wing tip 422 and 424 to contact a surface, thereby forming a smooth, finished appearance. This configuration also keeps the fibers in the extrusion and does not encourage unapproved access to the fibers due to the limited visibility of the seam.
[0089] Referring particularly to FIGS. 13 and 14 , test apparatus 179 is depicted. Test apparatus 179 generally includes block 180 , having corner 182 and corner 184 . Block 180 further presents passage 186 therethrough. Test apparatus 179 further includes wedge 188 and string 190 . String 190 is passed through passage 186 and wedge 188 secures string 190 at the top passage 186 . Test apparatus 179 further includes angle 192 . Trim piece 110 is secured in angle 192 and, for testing, presents hole 194 passing through trim piece 110 through which string 190 passes. Angle 192 presents hole 196 passing through angle 192 through which string 190 also passes. Support plate 198 is secured to string 190 below angle 192 . String 190 passes through support plate 198 at hole 200 and secured to support plate 198 . Angle 192 further includes first angle side 202 and second angle side 204 .
[0090] Referring particularly to FIG. 14 , end block 206 is secured to angle 192 . End block 206 is formed from rigid material and secured to angle 192 in such a way as to abut block 180 at juncture 208 . End block 206 presents end 210 which, according to the depicted embodiment, is coplanar with end of angle 192 .
[0091] In operation, trim piece 110 is secured at a juncture between two surfaces that meet at approximately 90°. Other angles can be accommodated by changes in the angular structure of trim piece 110 . First wing tip 122 and second wing tip 124 are deformed by pressure applied to trim piece 110 . Adhesive 138 and adhesive 140 adhesively adhere to the angle structures to which trim piece 110 is applied.
[0092] An important issue identified by the inventors of the present invention is the interaction between adhesive 138 , adhesive 140 and the flexible resiliency of first wing tip 122 and second wing tip 124 . Adhesive 138 and adhesive 140 must have sufficient adhesive qualities to overcome the flexible resiliency of first wing tip 122 and second wing tip 124 . Thus, adhesive 138 and adhesive 140 secure trim piece 110 for a long term while also providing sufficient adhesive force against first wing tip 122 and second wing tip 124 to resist the resiliency of first wing tip 122 and second wing tip 124 to seal trim piece 110 to the corner to which it is applied.
[0093] Referring particularly to FIGS. 13 and 14 , the inventors of the present invention have also invented a test apparatus to determine appropriate qualities for adhesive 138 and adhesive 140 as related to the flexible resiliency of first wing tip 122 and second wing tip 124 . The material of which body 112 is made, is related to determining the relationship between the adhesive and first wing tip 122 and second wing tip 124 .
[0094] To perform testing according to an embodiment of the presently described invention, a section of trim piece 110 is cut to a standard length and placed in angle 192 to test the flexibility of first wing tip 122 and second wing tip 124 . Angle 192 is a rigid structure pierced by hole 196 . Block 180 is placed on top of a section of trim piece 110 to be tested. String 190 is passed through hole 192 and then through hole 194 in trim piece 110 . String 190 is secured in place by the application of wedge 188 . Weights are then applied to support plate 198 which draws string 190 downward, thus applying force to trim piece 110 . The flexible resiliency qualities of first wing tip 122 and second wing tip 124 can thus be determined by observing the flexure of first wing tip 122 and second wing tip 124 along with the amount of weight applied to support plate 198 . Accordingly, the flexible resiliency of first wing tip 122 and second wing tip 124 can be determined, thus allowing determination of the required qualities for adhesive 138 and adhesive 140 .
[0095] The design of first wing tip 122 and second wing tip 124 of trim piece 110 as disclosed herein, is important to the effectiveness of adhesive 138 and adhesive 140 and long term performance of trim piece 110 . The relationship between the wings and the adhesives is engineered so to create an equilibrium between flexibility of first wing tip 122 , second wing tip 124 and the ability of adhesive 138 , 140 to resist peel and tensile forces which may otherwise cause premature failure.
[0096] The inventors have observed that the stiffness of first wing tip 122 and second wing tip 124 is determined in part by the durometer measured by Shore a of the polymer resin. Polymer resins may include polyvinyl chloride, polyurethane, silicone, bio-polymers, other petroleum resins and bioresins or a blend of both petroleum and bioresins. In addition to durometer, temperature can also have an effect on the flexibility of the polymer. This is particularly true of polyvinyl chloride material.
[0097] In designing a uniformed testing mechanism to determine this relationship a specific weight is placed on plate 198 , attached to string 190 , that passes through hole 196 of angle 192 and continues through hole 196 of block 180 . The string 190 is anchored by wedge 188 . Trim piece 110 rests against first angle side 202 and second angle side 204 . Weight is applied to plate 198 until first wing tip 122 and second wing tip 124 flexed down against angle sides 202 and 204 .
[0098] Adhesive 138 , 140 must withstand the peel and tensile forces resulting from the resiliency of first wing tip 122 and second wing tip 124 which is related to the durometer measured by Shore A properties of trim piece 110 . Accordingly, if equilibrium is properly attained adhesive 138 , 140 maintains an effective bond between trim piece 110 and an angle structure to which trim piece 110 is applied.
[0099] According to test parameters utilized herein, a two inch long piece of trim piece 110 is tested at 70° Fahrenheit. Various trim pieces 110 tested have a durometer measured by Shore A ranging from 55 to 90. Adhesive 138 , 140 tested have a 180° peel adhesion, when applied to stainless steel, of between 40 ounces per inch and 85 ounces per inch.
[0100] Test results determine that the amount of weight required to flex first wing tip 122 and second wing tip 124 to achieve contact with angle 192 range between a weight of 128 grams and 294 grams with the described test apparatus.
[0101] Wing length of first wing tip 122 and second wing tip 124 according to the invention is determined by the intersection of imaginary line 150 and imaginary line 152 through first wing tip 122 and second wing tip 124 . If adhesive 138 and adhesive 140 has a thickness of X, then the length of first wing tip 122 and second wing tip 124 from the intersection lines 150 and 152 with first wing tip 122 and second wing tip 124 shall be at least equal to X.
[0102] According to one example embodiment of the invention, the length of first wing tip 122 and second wing tip 124 has a two to one ratio with the thickness of adhesive 138 and adhesive 140 .
[0103] According to another example embodiment of the invention, a wing flex test was performed to determine the amount of weight required to flex first wing tip 122 and second wing tip 124 into angle 192 . Results of this testing are depicted in FIG. 15 .
[0104] A surface bonding test was also performed to determine the relationship between wing flexibility and peel adhesion of adhesive tapes after application of trim piece 110 .
[0105] Test parameters included test samples 3.5 inches in length having a finished face of 0.543 inches. The trim piece was applied to rigid PVC angle 192 and monitored at various intervals to determine any failure of the bond between the adhesive tape to angle 192 or the adhesive tape to trim piece 110 . Trim pieces 110 tested that were formed from PVC were primed with 3M primer 94 , while a polyurethane trim piece 110 was primed with acetone. Adhesive tape used was a proprietary Siltak® tape which utilizes a silicone adhesive with a 180° peel adhesion of 35 ounces per inch.
[0106] Monitoring parameters test samples were checked for delamination at intervals of 1 hour, 6 hours, 24 hours, 48 hours and 60 hours. Delamination was determined by any separation of adhesive tape from the rigid PVC angle 192 and/or separation of adhesive tape from the PVC or polyurethane trim piece 110 being tested. Test results are presented in FIGS. 15 and 16 . Based on the testing, trim piece 110 according to the invention using the proprietary Siltak® adhesive requires a durometer measurement by Shore A of between 80 and 85 for PVC trim pieces 110 and a durometer measurement of Shore A of between 60 and 70 with polyurethane trim pieces 110 .
[0107] The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and reference should be made to the drawings rather than the foregoing discussion of preferred examples, to assess the scope of the invention. | A trim piece for receiving and concealing wire having an elongated unitary structure of indeterminate length which when viewed in cross section, includes a body presenting a first wing portion and an opposed second wing portion and an intervening decorative surface on an outwardly visible face comprising a flap extending between the first wing portion and the second wing portion, the first wing portion and the second wing portion extending outwardly away from the body and terminating in a substantially knife edge, wherein a channel is disposed in the body, whereby the channel is capable of receiving a fiber wire, whereby the body includes an aperture and a seam for providing access to the aperture, whereby the seam is formed by an overlap between the flap and an inner flap. | 4 |
CLAIM OF PRIORITY
This present application is a continuation application of U.S. patent application Ser. No. 13/416,125, filed Mar. 9, 2012, entitled “Lighting Design of High Quality Biomedical Devices” which is a continuation application of and claims priority to U.S. patent application Ser. No. 12/691,601, filed Jan. 21, 2010, entitled “Lighting Design of High Quality Biomedical Devices” which claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/147,040, filed on Jan. 23, 2009, entitled “Lighting Design of High Quality Biomedical Devices,” all of which applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to using Light Emitting Diodes for illumination.
BACKGROUND OF THE INVENTION
Among the trends redefining 21st century biomedical diagnostics and therapeutics is the design of low-cost portable analyzers. Because light is a powerful tool in many of today's most widely used life science instruments, high intensity, low cost light engines are essential to the design and proliferation of the newest bio-analytical instruments, medical devices and miniaturized analyzers. The development of new light technology represents a critical technical hurdle in the realization of point-of-care analysis.
SUMMARY OF THE INVENTION
Embodiments of the present invention are directed to methods and devices for converting the output of a specific color LED and generating a broader band of wavelengths of emission including not only the specific color but additional color output. Specific embodiments, as will be described below, minimize backward directed light while increasing the total range of wavelengths emitted.
Lighting for life sciences is a broad and general category. Not only are the source specifications varied but so too are the equally important optical delivery requirements. Spectral and spatial lighting requirements for sensing on the head of an optical probe or within a single cell in a flowing stream differ in output power by orders of magnitude from the requirements of a multi-analyte detection scheme on an analysis chip or within the wells of a micro-titer plate. The number of colors, spectral purity, spectral and power stability, durability and switching requirements are each unique. Illuminating hundreds of thousands of spots for quantitative fluorescence within a micro-array may be best served by projection optics while microscopes set demanding specifications for light delivery to overfill the back aperture of the microscope objective within optical trains specific to each scope body and objective design.
While lighting manufacturers cannot provide all things to all applications, it is precisely this breadth of demand for which a light engine can be designed. To that end, products are not simple sources, but rather light engines: sources and all the ancillary components required to provide pure, powerful, light to the sample or as close to it as mechanically possible. Such designs have resulted in products that embody a flexible, hybrid solution to meet the needs of the broad array of applications for biotech. A qualitative comparison of light engine performance as a function of source technology is summarized in Table 1.
TABLE I
A qualitative comparison of light engine performance
as function of the source technology employed
Source
Useable
Unifor-
Temporal
Heat
Dura-
Technology
Light
mity
Response
Generation
bility
Cost
Arc Lamp
med
poor
none
high
low
high
Laser
high
poor
none
low
low
very high
LED
low
poor
fast
low
high
medium
Tungsten
low
poor
none
medium
low
medium
Light Pipe
high
high
fast
low
high
low
Historically arc lamps are noted to be flexible sources in that they provide white light. The output is managed, with numerous optical elements, to select for the wavelengths of interest and for typical fluorescence based instruments, to discriminate against the emission bands. However their notorious instability and lack of durability in addition to their significant heat management requirements make them less than ideal for portable analyzers. Moreover, large power demands to drive them present a barrier to battery operation within a compact design.
Lasers require a trained user and significant safety precautions. While solid state red outputs are cost effective, the shorter wavelength outputs are typically costly, require significant maintenance and ancillary components. Color balance and drift for multi-line outputs is a serious complication to quantitative analyses based on lasers. Moreover, the bulk of fluorescence applications do not need coherent light, are complicated by speckle patterns and do not require such narrow band outputs. Overcoming each of these traits requires light management and adds cost to the implementation of lasers for most bio-analytical tools.
Finally LEDs, have matured significantly within the last decades. LEDs are now available in a relatively wide range of wavelengths. However their output is significantly broad so as to require filtering. Additionally, output in the visible spectrum is profoundly reduced in the green, 500-600 not. The LED also presents trade-offs with respect to emission wavelength dependent intensity, broad emission spectrum (spectral half width on the order of 30 nm or more), poor spectral stability, and the wide angular range of emission. In addition, the process used to manufacture LED's cannot tightly control their spectral stability; anyone wishing to use LED's in applications requiring a good spectral stability must work directly with a supplier to essentially hand-pick the LED's for the particular application. Finally, LED's generate light over a wide angular range (50% of light intensity emitted at 70°). While optics can narrow the emission band and focus the light output, the resulting loss in power and increase in thermal output further limit the feasibility of LED light engines.
Most importantly, these light technologies cannot be readily improved for bioanalytical applications. The associated light engine market simply does not justify the large investment necessary to overcome fundamental performance limitations. As a result, analytical instrument performance and price is constrained by the light source with no clear solution in sight. Moreover the numerous manufacturers of lamps and lasers provide only a source, not an integrated light engine. Companies such as ILC Technology, Lumileds, Spectra-Physics, Sylvania and CooILED require some sort of mechanics and or electro-optics such as acousto-optic tunable filters (AOTFs), excitation filters (with a wheel or cube holder), shutters and controllers.
While no one lighting solution can best satisfy all instrument architectures, a light pipe engine combines the best of solid state technologies to meet or outperform the traditional technologies listed in Table I on the basis of all figures of merit for all individual wavelengths. Key to this performance is the light pipe architecture. Single outputs, such as red from a diode laser, may be competitive. However, no family of outputs can by assembled that bests the light pipe disclosed herein. In an embodiment of the invention, a light pipe engine can emit narrowband light exceeding 500 mW/color with intensifies up to 10 W/cm 2 depending on the application. In an embodiment of the invention, bandwidths as narrow as 10 nm are achievable. While such output power and overall emission intensity is impressive, the most significant figure of merit for quantifying the value of any lighting subsystem for bio-analytics is the intensity of high quality illumination provided to the sample. This is a factor dictated by the instrument design and sample volume and clearly very application specific.
In the case of medical devices and portable diagnostics the present light pipe invention offers a smart alternative for light generation. The light pipe engine is an optical subsystem; it consists of lamp modules for each discrete output based on solid state technologies tailored to best satisfy that output requirement complete with collection and delivery optics. The capabilities of the light pipe engine are highlighted in Table 2. The high performance illumination provided by the light pipe engine is embodied in a single compact unit designed to replace the entire ensemble of lighting components. The sources, excitation filters, multicolor switching capabilities and fast pulsing are contained within one box such that no external optics or mechanics are required.
TABLE II
Light pipe engine metrics of an embodiment of the invention, designed to
meet the needs for portable fluorescence assays and biomedical devices.
Key Metrics:
Spectral Output
Up to eight colors spanning UV-Vis-NIR
≧100 mW/spectral band
1-10 W/cm
Peak Wavelength
Optimal for different floors, adjustable bandwidths
Power Stability
>99% over 24 hours
Spectral Width
10 to 50 nm
Spectral Drift
<1% in 24 hours
Color Dependence
None
Lifetime
>5000 hrs
Footprint
amenable to portability
Maintenance
None, no replacement components for the light engines
lifetime
An inexpensive lighting solution, uniquely well suited to the production of safe, effective and commercially viable life science tools and biomedical devices can be attained using a solid-state light engine. In an embodiment of the invention, this light engine can provide powerful, pure, stable, inexpensive light across the Ultraviolet—visible—near infrared (UV-Vis-NIR). Light engines are designed to directly replace the entire configuration of light management components with a single, simple unit. Power, spectral breadth and purity, stability and reliability data will demonstrate the advantages of these light engines for today's bioanalytical needs. Performance and cost analyses can be compared to traditional optical subsystems based on lamps, lasers and LEDs with respect to their suitability as sources for biomedical applications, implementation for development/evaluation of novel measurement tools and overall superior reliability. Using such sources the demand for portable, hand-held analyzers and disposable devices with highly integrated light sources can be fulfilled.
Lamp
In various embodiments of the present invention, a lamp emits wavelengths of light, which excite fluorescence from photosensitive targets in the sample of interest. In various embodiments of the present invention, a lamp can be in the form of a tube, rod, or fiber of varying or constant diameter. In various embodiments of the present invention, a constituent light pipe can be made of glass, plastic, single or multiple inorganic crystal(s), or a confined liquid. In various embodiments of the present invention, a pipe either contains or is coated with a layer or layers containing, a narrow band luminescent material such as organic or inorganic compounds involving rare earths, transition metals or donor-acceptor pairs. In various embodiments of the present invention, a lamp emits confined luminescence when excited by IR, UV, or visible light from an LED, Laser, fluorescent tube, arc lamp, incandescent lamp or other light source. In an embodiment of the present invention, a lamp operates through the process of spontaneous emission, which results in a much larger selection of available wavelengths than is available for efficient stimulated emission (laser action).
Relay Optics
In an embodiment of the present invention, relay optics consist of light pipes, optical fibers, lenses and filters, which optically transport the light from a lamp to one or more capillaries and light pipes, optical fibers, lenses and filters which collect and transport any generated fluorescence to an appropriate detector or array of detectors, in conjunction with adaptors for coupling the excitation light into the capillaries, coupling the emission light out of the capillaries and for enhancing physical discrimination of the excitation and emission. In an embodiment of the present invention, relay optics, including fibers, can be constructed in a loop or as a cavity so that light from a lamp can pass through one or more capillaries multiple times to enhance excitation efficiency.
In an embodiment of the present invention, a number of lamps each emitting one or more color of light can have their constituent light pipes coupled in parallel or in series acting to produce multiple colors simultaneously or in sequence. In an embodiment of the present invention, one or more lamps can illuminate single channels, multiple parallel channels, multiple channels in multiple dimensions, numerous spots along the analysis channel and/or reservoirs connected to the flow streams.
In an embodiment of the present invention, lamps can be illuminated continuously during the measurement process or can be pulsed on and off rapidly to enable time-based detection methods. In an embodiment of the present invention, a lamp can be switched off between measurements, to eliminate the heat output. This can be contrasted with alternatives such as arc lamps or lasers that are unstable unless they are operated continuously.
Illumination and Collection System
In an embodiment of the present invention, a flexible illumination and collection system for capillary/fluorescence apparatus allows for a varying number of samples to be analyzed simultaneously. ‘Simultaneously’ is herein defined as occurring close in time. Two light pipes can irradiate two capillaries at the same time and the fluorescence from the molecules in one of the capillaries can be delayed due to physical or chemical effects relating to absorption, phosphorescence and/or fluorescence resulting in a delay in the fluorescence from the molecules in one of the capillaries. This excitation is still considered to result in ‘simultaneous detection’. In an embodiment of the present invention, an illumination and collection system can be adjusted for uniform illumination of multiple capillaries. In an embodiment of the present invention, illumination systems can irradiate an array of channels in an array of capillaries. In an embodiment of the present invention, an array of channels can be etched, molded, embossed into the capillaries. In an embodiment of the present invention, a set of wells intimately connected to fluidic conduits can be stepped along the length of the fluidic conduit such that they can be interrogated at numerous sites for the purposes of creating a map or image of the reacting species.
In an embodiment of the present invention, an illumination and collection system can emit multiple colors as desired. In an embodiment of the present invention, an illumination and collection system can be pulsed on and off as desired to reduce heat generation. In an embodiment of the present invention, an illumination and collection system can be pulsed on and off to allow time-based fluorescence detection.
In an embodiment of the present invention, illumination systems can irradiate homogeneous reactions within fluidic conduits or reservoirs. In an embodiment of the present invention, illumination systems can irradiate heterogeneous reactions on the surface of fluidic conduits or reservoirs. In an embodiment of the present invention, illumination systems can irradiate homogeneous or heterogeneous reactions on the surface of or within the pores of a porous reaction support.
Other objects and advantages of the present invention will become apparent to those skilled in the art from the following description of the various embodiments, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
Various embodiments of the present invention can be described in detail based on the following figures, wherein:
FIG. 1 shows a schematic of a light engine subsystem consisting of a lamp module and delivery optics;
FIG. 2 shows light engine output relative to a typical metal halide lamp and 75W xenon bulb;
FIG. 3 shows light pipe engine with <10 ns rise and fall times for fast switching between bands;
FIG. 4 shows light engine stability over 24 hours of use;
FIG. 5 shows a eight color light engine layout, including a light pipe and five other solid state light sources, with dichroic mirrors to create a single coaxial 8-color beam. Each individual light source is collimated so as to be efficiently combined and after color combination, the beam is refocused into a light guide for transport to the device or system to be illuminated according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Shown in FIG. 1 , is the light pipe engine 100 of an embodiment of the invention. An individual lamp module driven by light pipe technology consists of an excitation source 102 , typically one or more LEDs, and a light pipe 104 . In an embodiment, the excitation source 102 and light pipe 104 can be housed in a cylindrical waveguide 106 . The excitation source 102 drives luminescence in the light pipe 104 , which is composed of a glass or polymer fiber. In an embodiment, light pipe 104 includes a mirror 108 . Glass fibers are either doped with a rare earth metal or activated with a transition metal. Polymer fibers are doped with a dye. The fibers have fast response and decay times and can achieve a high efficiency through the design of delivery optics. The design and selection of the fiber determines the peak wavelength of the output illumination; options exist to span the UV-Vis-NIR spectrum. The bandwidth of the luminescence is narrow and can be further defined with the use of band pass filters 110 integrated into the delivery optics. In an embodiment, the delivery optics may include a band pass filter 110 connected to a coupler 112 , which can be attached to an optical delivery pipe 114 which leads to an instrument (e.g., a microtiter plate) 116 . Output intensity is determined through the design of the pipe's excitation source.
The light pipe geometry provides a unique opportunity to shape and direct the angular and spatial range of outputs. Combined with a high output power, the delivery optics can be readily tailored to couple the light with various instruments and analyzers. Sensors, optical probes, microscope objectives or through liquid light guides, two-dimensional oligomer and micro fluidic chips, and micro titer plates are all illumination fields that light pipe engines can readily support. Moreover, high output power enables illumination of large areas within a chip, micro array or micro titer plate and, as a result, support high-speed throughput in instruments where to date only scanning modes of operation could be envisioned.
The preferred mode of light pipe excitation is the application of one or more LED's. This approach takes advantages of the benefits of LED illumination: low cost, durability, and, at an appropriate excitation wavelength, high output power to drive the light pipe. In so doing the LED's shortcomings are managed. The lack of spectral stability and the high angular output characteristic of LED's do not impact the luminescence of the light pipe. Instead, the innovation of the light pipe enables circumvention of the principle of etendue conservation. All light sources must conform to this dictate, which requires the spread of light from a source never exceed the product of the area and the solid angle. Etendue cannot decrease in any given optical system.
The ability to modulate solid-state source outputs provides a unique opportunity for multiplexed fluorescent assays. Current light engine designs employ solid state materials with fast luminescence (approximately 10 ns.) The light pipe and LED have similar modulation capabilities thus multiple light pipes tuned to different output wavelengths can be employed to selectively detect multiple fluorescent tags within a given analysis. In addition, pulse modulation and phase modulation techniques enable fluorescence lifetime detection and afford improved signal to noise ratios. Each of the solid state units is truly off when it is off so low background signals and high contrast ratios are possible.
Table III shows an embodiment of the present light pipe engine invention's product and performance features. As improvements are made to LED's and the cost of semiconductor lasers continue to decline, the tool chest of options available to light lipe engines will continue to evolve. The desired light engine can ultimately be powered by a combination of light pipe, LED's and lasers. The knowledge and competency to integrate any of these lighting technologies into the delivery optics supports the requirements of each specific application and provides technical and commercial value.
TABLE III The light pipe engine feature set. Wavelengths UV-Vis-NIR Colors Up to eight Intensity 1-10 W/cm 2 Bandwidths Adjustable Size Compact Ease of Use Yes Modulation Up to 5 kHz Color control Independent System Control Manual or computer Heat output Minimal Life time Long
Eight Light Engine Subsystem
FIG. 5 shows a schematic for a eight color light engine layout. In an embodiment of the invention, a eight color light engine 500 includes a luminescent rod 502 and five other solid state light sources 504 , with dichroic mirrors 506 to create a single coaxial 8-color beam 508 (for example selected from UV 395 , Blue 440 , Cyan 485 , Teal 515 , Green 550 or 575 , Orange 630 and Red 650 nm) leading to an output 510 . In this embodiment, a manual or electromechanical filter slider 512 allows green yellow filtering of YAG generating 550 or 575 nm light. Additional colors can be used. For example, a color band centered at 550 nm can be replaced with a color band centered at 560 nm. Each individual light source is collimated so as to be efficiently combined and after color combination, the beam is refocused into a light guide for transport to the device or system to be illuminated according to an embodiment of the invention.
The light engine subsystem is designed to interface to the array of bioanalytical tools with the expectation that the end user can take for granted the high quality of the illumination. Table IV summarizes four bioanalytical applications for which light engines including light pipes could replace more traditional illumination subsystems and offer performance and cost advantages. For example, Kohler illumination in transmitted light microscopy requires that the light be focused and collimated down the entire optical path of the microscope to provide optimal specimen illumination. Even light intensity across a fairly large plane is a critical requirement. For stereomicroscopy, lighting is achieved with ring-lights at the objective and fiber optic lights pointed at the specimen from the side. In both cases, the light engine must efficiently couple to a fiber optic cable.
TABLE IV
Performance and cost analysis of the light pipe engine vs. traditional
illumination subsystems in four key bioanalytical applications
specification
Sanger Sequencing
Q-PCR
Flow Cytometry
Fluorescence Microscopy
Light engine
Light Pipe
Ar Ion Laser
Light Pipe
Metal Halide
Light Pipe
Lasers
Light Pipe
Metal Halide
Intensity
150-250
150-250
0.5-1
0.2-1, very
150-250
150-250
<50
1-50, very
W/cm 2
λ specific
λ specific
Wavelength
505 nm
multiline
4 colors
>2 colors
4 colors
Bandwidth, nm
10-30
26
10-30
15
10-30
<5
10-30
15
Stability
0.1%
>1%
0.1%
>1%
0.1%
>1%
0.1%
>1%
Switching, ms
<0.03
1-10, ext.
<0.03
40, ext.
<0.03
1-10, ext.
<0.03
40, ext.
shutter
shutter
shutter
shutter
MTBF, hrs
>10,000
<4,000
>10,000
<1,000
>10,000
<4,000
>10,000
<1,500
Price
<$3K
>$5K
<$7.5K
>$10K
<$5K
>$5K
<$7.5K
>$10K
For portable diagnostic tools, the delivery optics must provide even illumination over a small volume. These requirements are similar to, but less restrictive than those presented by capillary electrophoresis. Capillary electrophoresis requires an intense (10 mW) light focused onto the side of a capillary tube with characteristic dimensions on the order of a 350 pm outer diameter and a 50 pro inner diameter. To achieve this goal, the delivery optics were comprised of a ball lens to collect and collimate light from the lamp module (already coupled into an optical fiber), a bandpass filter to provide a narrow bandwidth of illumination, and an aspheric lens to focus the light at the center of the capillary bore. This approach yielded an 80 pin spot size and the desired 10 mW of delivered power to the capillary tube.
The design of delivery optics for microfluidic immunoassays requires both the even illumination required for optical microscopy and the small volume illumination required for capillary electrophoresis. Light engines capable of delivering even illumination at the active sites in a microfluidic array for detection of fluorescent tagged biomarkers have been designed for immunochemical as well as genomic applications. The advantages of the luminescent light pipe are providing commercial, readily available light engine solutions for illumination-detection platforms optimized for portable diagnostic tools.
Spectral Bands and Output Power
In various embodiments of the present invention, the light pipe engine performs well compared with the output power across the visible spectrum to other lamps (see FIG. 2 ). Such comparisons beg for disclaimers as the outputs of the commonly employed lamps change in time and degrade with usage. The light pipe engine is all solid state so they it is significantly more stable and reproducible. FIG. 2 was taken within the manufacturers' specified lifetime for each lamp, by an independent user well trained in biophotonics, these outputs represent typical performances of a common metal halide bulb, 75 W xenon bulb and that of the light pipe engine.
Such output comparisons are further complicated by mismatches between the spikes of the metal halide bulb and light pipe light engine output bands, However, noting such disparities it is fair to claim the outputs of the light engine across the visible spectrum compare well against the outputs of a metal halide bulb in spectral windows that match the excitation energies of some of the most commonly used fluors for biotech: around 390 nm where DAPI and Hoescht can be excited; in the window most commonly associated with a cyan line of an argon ion laser and often used to excite Alexa dyes, green fluorescent proteins and fluoresceins; and in the red where neither of the lamps provides appreciable power for the likes of Cy5. The light engine also bests the Xenon lamp across the palate of excitation wavelengths most common to biotech: the Xenon lamp underperforms particularly in the violet, cyan, blue and red regions of the visible spectrum. Of course, more powerful Xenon lamps are often employed to provide enhanced performance at a significant maintenance cost.
In another embodiment of the present invention, as seen in FIG. 2 , the output of the green and amber bands have essentially doubled, such that on a photon per photon basis the area under the curve for the arc lamp vs. light engine are the same. Certainly the peak shapes, and figures of merit (height, FWHM, etc.) differ. However, no compromise in output power, even for the 546 nm band of the arc lamp, should be incurred as a consequence of using a light pipe engine replacement.
Alternatively, a light pipe engine can be employed in a short duty cycle mode for power starved applications. When feasible, pulse widths of less than 100 ms at 10% duty cycles can actually improve the power output per band by a factor of 1.5 to 2.0 over longer duty cycles or in continuous mode of operation. Applications that employ multiple lasers and acousto-optic tunable filters (AOTFs) but need safe, cost effective and easy to employ lighting solutions might benefit from such light engine performance. Fluorescence microscopy for multicolor detection could take advantage of this option, for example. As could numerous other bioanalytical platforms such as a light engine replacement for the optical excitation from AOTF-based multicolor fluorescence detection for short tandem repeat (STR) analysis in a micro-electrophoretic device, a glass microchip.
Fast Switching
Because of the solid state nature and independently operable designs of the lamp modules, coupled to fast (approximately 10 ns) decay times of typical materials employed, a light pipe based light engine outperforms any broad spectrum source in terms of support for fast analyses. Lamp based sources are coupled to filters and/or shutters with mechanical supports that relegate them 1 to 50 millisecond regimes. Even LED based lamps require filtering for most quantitative fluorescence based analyses. The light pipe based light engine incorporates all that filtering into its highly integrated design. Therefore switching times are limited today by the electronics of the boards controlling the sources. Rise times of less than 20 μs and fall times of less than 2 us are typical (see FIG. 3 ). Moreover each color can be switched independently and is compatible with triggering by TTL, RS232 and USB and intensity control by RS232, USB or manually. This supports experiments where simultaneous excitation of multiple tags could previously only be done with multipass excitation filters and broadband sources. Using a light pipe engine, effectively instantaneous excitation of individual reporters can be manipulated within microsecond time frames to achieve rapid, serial exposure of a biologic event to the various excitation bands with no external hardware beyond the light engine itself.
Stability
Because a light pipe based light engine is based on solid state technologies, they are extremely stable both in short duration experiments and over long term use. FIG. 4 depicts this stability. Light engines are powered by 24 V power supplies operated in DC mode, therefore there is no 60 Hz noise. All colors perform similarly. In 24 hours of continuous operation, the output fluctuates on the order of 1%. Short term stability on the order of 1.0 ms is approximately 0.5%. Short term stability for 0.1 ms is diminished by a factor of ten to 0.05%.
The foregoing description of the various embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. Embodiments were chosen and described in order to best describe the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention, the various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Other features, aspects and objects of the invention can be obtained from a review of the figures and the claims. It is to be understood that other embodiments of the invention can be developed and fall within the spirit and scope of the invention and claims | The invention relates to a plurality of light sources to power a variety of applications including microarray readers, microplate scanners, microfluidic analyzers, sensors, sequencers, Q-PCR and a host of other bioanalytical tools that drive today's commercial, academic and clinical biotech labs. | 6 |
FIELD OF THE INVENTION
The invention is directed to packet switching networks (PSN), particularly to configuring services thereon using policies.
BACKGROUND OF THE INVENTION
Virtual Leased Line (VLL) is a service for providing Ethernet based point to point communication over Internet Protocol (IP) and Multi Protocol Label Switching (MPLS) networks (IP/MPLS). This technology is also referred to as Virtual Private Wire Service (VPWS) or Ethernet over MPLS (EoMPLS). VLL service provides a point-to-point connection between two Customer Edge (CE) routers. It does so by binding two attachment circuits (AC) to a pseudowire that connects two Provider Edge (PE) routers, wherein each PE router is connected to one of the CE routers via one of the attachment circuits. VLL typically uses pseudowire encapsulation for transporting Ethernet traffic over an MPLS tunnel across an IP/MPLS backbone. More information on pseudowires can be found in “Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture”, RFC3985, IETF, March 2005, by S. Bryant and P. Pate.
Virtual Private LAN Service (VPLS) is an Ethernet service that effectively implements closed user groups via VPLS instantiations. In order to achieve full isolation between the user groups, VPLS dedicates a separate database, usually in the form of a forwarding information base (FIB), on network routers per VPLS instance. Each VPLS instance further requires that a dedicated mesh of pseudowire tunnels is provisioned between PE routers that are part of the VPLS.
Both VLL and VPLS services use Service Access Points (SAP) to bind tunnel endpoints at PE routers ports to their respective service. For example, in the case of VPLS service a SAP would specify physical identifiers (e.g. node, shelf, card, port) of the corresponding port and an identifier (e.g. VLAN5) of the VPLS.
Services such as VPLS and VLL services provide the capability to securely communicate data packets among routers provisioned with the same service. Typically, thousands of such services are provisioned on a network, the data packet traffic that they each carry being kept separate from one another via special treatment provided at each router on which an instantiation of that service has been provisioned.
Each service has physical characteristics that in part define the service. These characteristics, also referred to a quality of service (QoS) parameters, include constant information rate (CIR), peak information rate (PIR), and maximum burst size (MBS) parameters and are often grouped into a policy for convenient provisioning of a service on a given router.
A service access point (SAP) provisioned on a router is used to associate a service instance with a port of the router and a policy. A SAP can also associate an override with a policy, wherein a value of one of the QoS parameters is specified to be used instead of the value for that QoS parameter defined by the associated policy.
Although policies and policy overrides are local to a router, it is desirable to define and use them on a network-wide basis for consistency. However, in a large network with thousands of routers, each having dozens of ports, and the even larger number of unique combinations of QoS parameter values that can be defined and assigned to these ports, limitations on the maximum number of policies that a network management (NM) system managing the network can support are easily exceeded. Using policy overrides to alleviate this problem only exacerbates difficulties in achieving network-wide consistency in the provisioning of services. Furthermore, since policies and policy overrides can be provisioned both locally at a router and centrally via a network management system, keeping the provisioning of services in synchronization at a NM system and network routers is difficult. Therefore, a means of configuring services on a PSN in a manner that ameliorates one or more of the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The invention is directed to configuring services in a packet switching network. Embodiments of the invention group existing policies configured on network routers into policy groups, thereby identifying redundant policies that may be eliminated by reconfiguring one or more of the network routers to reduce the overall network-wide number of policies. This functionality aims at efficient use of NM system resources to help avoid exceeding NM system policy limits.
One embodiment of the invention takes policy overrides into account during the grouping operation so that the policy overrides can be eliminated during the reconfiguration. This functionality aims at promoting consistent use of policies on a network-wide basis.
In one embodiment the grouping and reconfiguration is responsive to configuration changes initiated locally at a router, which are learned of via event notification from a NM system. This functionality aims at keeping router and NM system policies used in configuration of services in synchronization.
According to an aspect of the invention a method of configuring a service in a packet switching network is provided. The method includes the steps of: executing automatically instructions stored on a computer readable media, the instructions when executed causing a sequence of steps to be performed, the sequence comprising the steps of: determining a service access point to be affected by configuration of the service; obtaining policing information associated with the service access point from a router of the switching network; assigning the service access point to a policy group depending upon the policy information; updating, on the router in accordance with the assignment, provisioning information associated with the service access point to configure the service.
According to another aspect of the invention a system for configuring a service in a packet switching network is provided. The system comprises a service platform for executing a service application stored thereon, the service platform comprising: means for communicatively coupling to a network management entity of the packet switching network via an operating system interface; and a service database for storing a plurality of policy groups and their associated policies, wherein the service application comprises instructions stored on computer readable media to be executed by the service platform to cause a sequence of actions to be performed in cooperation with the management entity, the actions comprising: determining a service access point to be affected by configuration of the service; obtaining policing information associated with the service access point from a router of the switching network; assigning the service access point to a policy group depending upon the policy information; updating, on the router in accordance with the assignment, provisioning information associated with the service access point to configure the service.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments, as illustrated in the appended drawings, where:
FIG. 1 illustrates a network configuration according to a first embodiment of the invention;
FIG. 2 illustrates a method of configuring services in a packet switching network according to a second embodiment of the invention; and
FIG. 3 illustrates a network configuration according to a third embodiment of the invention;
In the figures like features are denoted by like reference characters.
DETAILED DESCRIPTION
Referring to FIG. 1 , a network configuration 10 for providing a VPLS service over an MPLS network 12 includes a first pseudowire tunnel T 1 routed through the MPLS network 12 between a first provider edge router R 1 and a second provider edge router R 2 . A service instance SVC of the VPLS service is instantiated at each of the provider edge routers R 1 , R 2 and associates the first pseudowire tunnel T 1 with the VPLS service. Accordingly, data packets associated with the VPLS service are communicated through the MPLS network 10 via the first pseudowire tunnel T 1 between the first and second provider edge routers R 1 , R 2 .
The MPLS network 10 also includes a second pseudowire tunnel T 2 routed through the MPLS network 12 between the first provider edge router R 1 and a third provider edge router R 3 . A service instance SVC of the VPLS service is instantiated at the third provider edge router R 3 and associates the second pseudowire tunnel T 2 with the VPLS service. Accordingly, data packets associated with the VPLS service may also be communicated through the MPLS network 10 via the second pseudowire tunnel T 2 between the first and third provider edge routers R 1 , R 3 .
A first customer edge router CE 1 is connected to a first interface port P 1 of the first provider edge router R 1 via a first attachment circuit AC 1 . The first customer edge router CE 1 has a first MAC address X. Similarly, a second customer edge router CE 2 is connected to a second interface port P 2 of the second provider edge router R 2 via a second attachment circuit AC 2 . The second customer edge router CE 2 has a second MAC address Y.
A first service access point SAP 1 associates the first interface port P 1 with the VPLS service SVC. The first provider edge router R 1 includes a first database DB 1 associated with the service instance SVC. The first database DB 1 includes information that associates the service SVC provisioned on the first PE router R 1 with the first pseudowire tunnel T 1 . Data packets received at the first port P 1 from the first attachment circuit AC 1 that are associated with the VPLS service SVC are forwarded to the primary pseudowire tunnel T 1 in accordance with the information in the first database DB 1 . Such information includes the forwarding information, which in this case causes data packets with a source MAC address being the first MAC address X to be forwarded over the first pseudowire tunnel T 1 when their destination MAC address is the second MAC address Y. Similarly, data packets associated with the VPLS service SVC received by the first provider edge router R 1 from the first pseudowire tunnel T 1 are forwarded to the first interface port P 1 in accordance with information in the first database DB 1 and the first service access point SAP 1 .
Similarly, a second service access point SAP 2 associates the second interface port P 2 with the VPLS service SVC, such that data packets received at the second port P 2 from the second attachment circuit AC 2 that are associated with the VPLS service SVC are forwarded to the first pseudowire tunnel T 1 in accordance with information in the second database DB 2 . Such information includes forwarding information, which in this case causes data packets with a source MAC address being the second MAC address Y to be forwarded over the pseudowire tunnel T 1 when their destination MAC address is the first MAC address X. Similarly, data packets associated with the VPLS service SVC received by the second provider edge router R 2 from the first pseudowire tunnel T 1 are forwarded to the second interface port P 2 in accordance with information in the second database DB 2 and the second service access point SAP 2 .
Typically, there would be multiple pseudowire tunnels connecting multiple provider edge routers. In some cases these tunnels form a fully connected mesh interconnecting the provider edge routers. In any case, when there are multiple pseudowire tunnels for a given service that terminate on a provider edge router, a database is used at that router to determine over which of the tunnels a data packet should be forwarded to reach its destination. This determination is made based on the destination MAC or IP address of the data packet. A MAC address is a 48 bit address that is generally unique and dedicated to a given network interface card or adapter of a data communication system. A MAC address is also known as a hardware address. An IP address is a 32 bit (IPv4) or 128 bit (IPv6) address that is generally unique to a network interface or system but is assignable in software.
In view of foregoing it should be clear that data packets associated with the VPLS service SVC can be communicated between the first and second customer edge routers CE 1 , CE 2 via their respective attachment circuits AC 1 , AC 2 , the first and second provider edge routers R 1 , R 2 , and the first pseudowire tunnel T 1 .
A third customer edge router CE 3 is connected to the third provider edge router R 3 via a third attachment circuit AC 3 connected to a third interface port P 3 at the third provider edge router R 3 . The third customer edge router CE 3 has a third MAC address Z. In a similar manner as described earlier for the first and second service access points SAP 1 , SAP 2 , a third service access point SAP 3 associates the third interface port P 3 with the VPLS service SVC instantiated on the third provider edge router R 3 .
The third service access point SAP 3 associates the third interface port P 3 with the VPLS service SVC. The third provider edge router R 3 includes a third database DB 3 associated with the service instance SVC. The third database DB 3 includes information that associates the VPLS service SVC provisioned on the third provider edge router R 3 with the second pseudowire tunnel T 2 . Data packets received at the third port P 3 from the third attachment circuit AC 3 that are associated with the VPLS service SVC are forwarded to the second pseudowire tunnel T 2 in accordance with information in the first database DB 1 . Such information includes forwarding information, which in this case causes data packets with a source MAC address being the third MAC address Z to be forwarded over the second pseudowire tunnel T 2 when their destination MAC address is the first or second MAC addresses X, Y. Similarly, data packets associated with the VPLS service SVC received by the third provider edge router R 3 from the second pseudowire tunnel T 2 are forwarded to the third interface port P 3 in accordance with information in the third database DB 3 and the third first service access point SAP 3 .
As mentioned previously, the databases DB 1 to DB 3 include information that associates their respective service access points SAP 1 to SAP 3 and respective ports P 1 to P 3 with the VPLS service SVC. For example, the first database DB 1 includes a first entry E 1 that associates the first service access point SAP 1 with the first interface port P 1 and VPLS service SVC, as well as a an identifier of a first policy PID 1 on the first PE router R 1 . A second entry E 2 in the first database DB 1 includes quality of service parameters of the first policy PID 1 . For example these QoS parameters have the values PIR=100 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps.
Similarly, the second database DB 2 includes a third entry E 3 that associates the second service access point SAP 2 with the second interface port P 2 and VPLS service SVC, as well as an identifier of a second policy PID 2 on the second PE router R 2 . A fourth entry E 4 in the second database DB 2 includes quality of service parameters for the second policy PID 2 . For example these QoS parameters have the values PIR=110 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps. The second database DB 2 has a fifth entry E 5 which is an override policy OPID 2 of the second policy PID 2 . For example, the fifth entry E 5 defines a PIR=100 Kbps, which overrides the PIR value in the fourth entry E 4 .
Similarly, the third database DB 3 includes a sixth entry E 6 that associates the third service access point SAP 3 with the third interface port P 3 and VPLS service SVC, as well as an identifier of a third policy PID 3 on the third PE router R 3 . A seventh entry E 7 in the third database DB 3 includes quality of service parameters for the third policy PID 3 . For example these QoS parameters have the values PIR=200 kilobits per second (Kbps), CIR=50 Kbps, and MBS=200 Kbps.
Still referring to FIG. 1 , the network configuration 10 includes a management entity 14 that is communicatively coupled to the provider edge routers R 1 to R 3 via a control connection 16 and the MPLS network 12 . The management entity 14 would typically be a network management system capable of performing operation, administration and maintenance (OAM) type functions on network elements in the MPLS network 12 such as the provider edge routers R 1 to R 3 . This functionality of the management entity 14 includes the capability to receive reports of equipment, service, and provisioning related events from network elements of the MPLS network 12 . The management entity 14 includes a management database MDB, which includes entries for the first, second, and third policies PID 1 to PID 3 and their respective QoS parameter values.
The network configuration 10 also includes a service platform 18 that is communicatively coupled to the management entity 14 via an open operating system (OS) interface 20 . Using the open OS interface 20 , the service platform 18 has access to event notifications 22 , which include event notifications related to the event reports from the network elements. Further using the open OS interface 20 the service platform 18 can issue control commands 24 to the management entity 14 including commands to effect provisioning changes at the provider edge routers R 1 to R 3 . The service platform 18 would typically be a laptop or desktop computer or workstation. The open OS interface is an Extensible Markup Language (XML) interface, although other types of message interfaces could be used.
The service platform 18 executes a service application 26 that is in communication with a service database 28 on the service platform 18 , although the service database 28 could also reside on the management entity 14 with access to it given by the open OS interface 20 . The service application 26 is a software program that embodies a method of configuring services in accordance with an embodiment of the invention. The service database 28 includes information on policy groups that have been derived according to the method. For example, this information includes an eighth entry E 8 for a first policy group PG 1 and a ninth entry E 9 for a second policy group PG 2 .
As indicated by the eighth entry E 8 , the first policy group PG 1 is associated with the first and second service access points SAP 1 , SAP 2 . A fourth policy PID 4 has been created based on QoS parameter values of the first and second policies PID 1 , PID 2 that are in common after taking any related override policies into account, specifically in this case the override policy OPID 2 . For example, the values of the QoS parameters of the fourth policy PID 4 are PIR=100, CIR=50, and MBS=200. Similarly, as indicated by the ninth entry E 9 , the second policy group PG 2 is related to the third service access point SAP 3 . A fifth policy PID 5 has been created based on QoS parameter values of the third policy PID 3 . The steps performed in order to derive the policy groups PG 1 , PG 2 will be described in more detail later with reference to FIG. 2 .
After creating the policy groups PG 1 , PG 2 the service application 26 issues control commands 24 to the management entity 14 to cause their associated respective policies PID 4 , PID 5 to replace in the PE routers R 1 to R 3 and management database MOB the policies PID 1 to PID 3 on which the policy groups PG 1 , PG 2 were based. This is indicated in FIG. 1 by the bold arrows and text. This replacement operation uses the identifiers of the policies to be replaced PID 1 to PID 3 , and may also use the service access points SAP 1 to SAP 3 for further correlation between the incoming PID 4 , PID 5 and outgoing policies PID 1 to PID 3 . For example, to make the replacement an identifier of the fourth policy PID 4 replaces that of the first and second policies PID 1 , PID 2 in the first and third entries E 1 , E 3 , respectively. Additionally, the policy information of the fourth policy PID 4 , such as the values of the QoS parameters PIR=100, CIR=50, MBS=200, replace those of the first and second policies PID 1 , PID 2 in the second and fourth entries E 2 , E 4 , respectively. In some cases, the policy information of the policy associated with the policy group to which the SAP is assigned may already exist on the router, in which case the policy previously associated with the SAP can be deleted if it is not associated with any other SAPs on the router. For example, if the fourth policy PID 4 already existed on the first router R 1 then the first policy PID 1 of the second entry E 2 could be deleted because that policy is not associated with any other SAP on the first router R 1 . Likewise, the same is true of unused policies in the management database MDB. The override policy OPID 2 is removed by deleting the fifth entry E 5 . Furthermore, an identifier of the fifth policy PID 5 replaces that of the third policy PID 3 in the sixth entry E 6 . Additionally, the policy information of the fifth policy PID 5 , such as the values of the QoS parameters PIR=200, CIR=50, MBS=200, replace those of the third policy PID 3 in the seventh entry E 7 . Finally, the fourth and fifth policies PID 4 , PID 5 with there associated QoS parameter values replace the first, second, and third policies PID 1 , PID 2 , PID 3 in the management database MDB.
Referring to FIG. 2 , a method 200 of configuring services in a packet switching network will now be described with additional reference to FIG. 1 . The method 200 includes an initial step of determining 202 routers that may be affected by operations that are carried out as part of the configuration of the services. This determination 202 could be the result of user input at the service platform 18 or management entity 14 . For example, an operator could specify the affected provider edge routers R 1 to R 3 . Additionally or alternatively, the affected routers could be derived by the service application 26 from event notifications 22 received over the open OS interface 20 . In this case the service application 26 would check the event notifications 22 to determine if any of them relate to provisioning of a policy or an override policy at the provider edge routers R 1 to R 3 or at the management entity 14 . In the affirmative, the affected routers would be determined from the event notifications 22 , either directly if explicitly indicated in the event notifications 22 or indirectly via information stored in the management database MDB or service database 28 . The service application 26 may additionally send control commands 24 to the management entity 14 to cause the management entity 14 to extract any relevant policy or policy override provisioning information from any router related to the event notifications 22 , or from the management entity 14 itself.
The method then proceeds to determining 204 service access points that may be affected by operations that are carried out as part of the configuration of the services. Typically, determining 204 the affected SAPs would be done based on the determination 202 of the affected routers. For example, the service application would send control commands 24 to the management entity to query which SAPs are provisioned on the affected routers. However, as with the prior step of determining 202 affected routers, the present step of determining 204 affected SAPs could be the result of user input at the service platform 18 or management entity 14 . For example, an operator could specify the affected service access points SAP 1 to SAP 3 . Additionally or alternatively, the affected SAPs could be derived by the service application 26 from event notifications 22 received over the open OS interface 20 . In either of the latter two cases, it is therefore possible to omit from the method 200 the step of determining 202 the affected routers.
The method then proceeds to obtain 206 policy information related to the affected SAPs. For example, the service application 26 issues control commands 24 to cause the management entity 14 to query network routers R 1 to R 3 for this policy information, such as that in the second, fourth, fifth, and seventh entries E 2 , E 4 , E 5 , E 7 , and provide the policy information to the to the service application 26 .
The method then proceeds to assigning 208 each affected SAP to an existing or new policy group depending upon the policy information obtained 206 in the previous step. This step is performed by the service application 26 on any given SAP by first applying to a policy specified for the SAP all override policies that correspond to that policy in order to update that policy, before searching in the service database 28 for a policy group that has QoS parameters that match those of the updated policy. If a matching policy group is found the SAP is assign to that matching policy group, otherwise a new policy group is created and the SAP is assigned to the new policy group. For example, in the case of the second service access point SAP 2 , the value of the QoS parameter PIR=110 in the second policy PID 2 is updated by the override policy OPID 2 , which has a QoS parameter value of 100. The updated second policy has QoS parameter values PIR=100, CIR=50, MBS=200, which match those of the first policy group PG 1 . The service application 26 therefore assigns the second service access point SAP 2 to the first policy group PG 1 , which is associated with the fourth policy PID 4 . In a similar manner the first service access point SAP 1 is assigned to the first policy group PG 1 , and the third service access point SAP 3 is assigned to the fifth policy PID 5 .
For each policy group and for each SAP assigned thereto, the method then proceeds to update 210 provisioning information of the SAP on a respective router with an identifier of the policy associated with the policy group as well update on the router any existing, or add any non-existing, policy information of the associated policy. For example regarding the first policy group PG 1 , the service application 26 issues control commands 24 to cause the management entity 14 to update provisioning information of the first service access point SAP 1 in the first entry E 1 by replacing the identifier of the first policy PID 1 with that of the fourth policy PID 4 . Likewise, the policy information of the fourth policy PID 4 is added to the first router R 1 by replacing the information of the first policy PID 1 in the second entry E 2 with that of the fourth policy PID 4 . In a similar manner, the provisioning information of the second access point SAP 2 is updated in the second router to reflect assignment of the second service access point SAP 2 to the first policy group PG 1 . Likewise, the provisioning information of the third access point SAP 3 is updated in the third router to reflect assignment of the third service access point SAP 3 to the second policy group PG 2 .
The method then proceeds to remove 212 any unused policies and policy overrides from routers affected by the updating 210 of provisioning information of the previous step. For example, the service application 26 issues control commands 24 to cause the management entity to remove the override policy OPID 2 of the fifth entry E 5 .
Finally, any unused policies are removed 214 from the management entity 14 . For example, the service application 26 issue control commands 24 to cause the management entity to remove the first, second, and third policies PID 1 , PID 2 , PID 3 from its management database MDB.
By executing the method 200 , the service platform 18 provides several advantages such as: more consistent use of policies on a network-wide basis, efficient use of NM system resources to help avoid exceeding NM system policy limits, and keeping router and NM system policies in synchronization. For example, with regard to the network configuration of FIG. 1 , the total number of policies and policy overrides was reduced by 50%; from four to two. Although this was a simplistic example, it should illustrate that advantages provided by embodiments of the invention applied to a network with thousands of policies and routers can be quite significant.
Referring to FIG. 3 , the network configuration 10 is the same as that in FIG. 1 except for the first to ninth entries E 1 to E 9 in the in the first to third databases DB 1 to DB 3 and service database 28 have been replaced with new entries, as will be explained in the following description. Some of these new entries have content that is changed at various points in time, while others are added or removed at various points in time. The points in time are sequential and are designated respectively as first to fifth time points Time 1 to Time 5 .
According to FIG. 3 , the first database DB 1 has a tenth entry E 10 that associates the first access point SAP 1 with a sixth policy PID 6 . An eleventh entry E 11 in the first database defines QoS parameters of the sixth policy PID 6 to be PIR=100, CIR=50, and MBS=200. A twelfth entry E 12 in the first database DB 1 defines a first override O 1 PID 6 for the sixth policy PID 6 , wherein a first override PIR value is defined as PIR=120. Likewise, the second database DB 2 has a thirteenth entry E 13 that associates the second access point SAP 2 with the sixth policy PID 6 . A fourteenth entry E 14 in the second database defines QoS parameters of the sixth policy PID 6 to be PIR=100, CIR=50, and MBS=200. A fifteenth entry E 15 in the second database DB 2 defines a second override O 2 PID 6 for the sixth policy PID 6 , wherein a second override PIR value is defined as PIR=110.
At the first time point Time 1 , the service application 26 obtains policy information regarding the first and seconds service access points SAP 1 , SAP 2 from the first and second databases DB 1 , DB 2 in a manner as previously described with reference to FIG. 1 and FIG. 2 . The service application applies the first and second overrides for the sixth policy O 1 PID 6 , O 2 PID 6 before assigning the first and second access points SAP 1 , SAP 2 to new or existing policy groups, again in the same manner as previously described. The resultant policy group assignment is stored in the service database 28 , for example as a sixteenth entry E 16 . In this case two new policy groups are created, a third policy group PG 3 for the first service access point SAP 1 and a fourth policy group PG 4 for the second service access point because of their different PIR values that result when their respective override policies O 1 PID 6 , O 2 PID 6 are applied.
At the second time point Time 2 , the first override PIR in the twelfth entry E 12 is changed to 140, and the second override PIR in the fifteenth entry E 15 is also changed to 140. These changes are shown in the figure by the boldface arrow and text.
At the third time point Time 3 the service application 26 again obtains policy information regarding the first and second service access points SAP 1 , SAP 2 from the first and second databases DB 1 , DB 2 . The service application 26 applies the first and second PIR overrides (PIR=140) before assigning the first and second access points SAP 1 , SAP 2 to new or existing policy groups. The resultant policy group assignment is stored in the service database 28 , for example as a seventeenth entry E 17 which replaces the sixteenth entry E 16 since that entry is no longer relevant. In this case a new policy group is created, a fifth policy group PG 5 , and both the first and second service access points SAP 1 , SAP 2 are associated with this group PG 5 . For clarity of this description the new policy group was assigned a new number, e.g. PG 5 , however it should be appreciated that an already used policy group number could have been used, e.g. PG 3 , PG 4 , if all entries specifying that policy group have already been deleted (e.g. E 16 ) from the service database 28 .
At the fourth time point Time 4 , the third database is provisioned with the third service access point SAP 3 and policy information that associates it with the sixth policy PID 6 . This result of this provisioning is shown as an eighteenth entry E 18 , which defines the third service access point SAP 3 and associates it to the sixth policy PID 6 , and a nineteenth entry E 19 , which provides the QoS parameters of the sixth policy as being PIR=140, CIR=50, MBS=200. This provisioning could be accomplished by entering information of the eighteenth and nineteenth entries directly at the third router R 3 , or entering that information at the management entity 14 , or by specifying at the service platform 18 that the information of the fifth policy group PG 5 should be used. In the later case, the provisioning would be effected as previously described, that is, by the service application 26 issuing control commands 24 to the management entity 14 to effect the provisioning.
At the fifth time point Time 5 , the service application 26 obtains policy information regarding the first to third service access points SAP 1 to SAP 3 from the first to third databases DB 1 to DB 3 . The service application 26 applies the first and second PIR overrides (PIR=140) before assigning the first and second access points SAP 1 , SAP 2 to new or existing policy groups. The resultant policy group assignment is stored in the service database 28 , for example as a twentieth entry E 20 which replaces the seventeenth entry E 17 since that entry is no longer relevant. In this case an existing policy group is used, the fifth policy group PG 5 , and the first to third service access points SAP 1 to SAP 3 are assigned with this group PG 5 since the policy information of each specifies the same policy, the sixth policy PID 6 , and their QoS parameters have the same values, namely PIR=140, CIR=50, and MBS=200.
From the foregoing description with reference to FIG. 3 , it should be appreciated the service application 26 with the method of configuring services that it embodies, is useful for promoting consistent use of policies on a network-wide basis, both in dealing with override policies on existing services, e.g. with regard to the first and second routers R 1 , R 2 , and in adding new services, e.g. with regard to the third router R 3 . The policy groupings, e.g. PG 1 to PG 5 , in the service database 28 can be considered as virtual groups in that they are not configured directly per se on the network routers, e.g. R 1 to R 3 , and the management entity 14 , but rather are created dynamically when needed, for example at request of a user or responsive to a configuration change detected via an event notification 22 .
Numerous modifications, variations and adaptations may be made to the embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims. | The invention is directed to configuring services in a packet switching network. Embodiments of the invention group existing service policies configured on network routers into policy groups, thereby enabling better management of service policies and policy overrides. This functionality can be useful for identifying redundant policies that may be eliminated by reconfiguring one or more of the network routers to reduce the overall network-wide number of policies, as well as provisioning new services in a manner that efficiently uses existing policies. | 7 |
BACKGROUND OF THE INVENTION
Dredge cutterheads are generally conical with a multiplicity of hard rock cutting teeth or replaceable edges projecting outwardly from a plurality of spaced helical support vanes or blades disposed about its conical surface. The cutterhead normally has a hub which fits around a shaft and provides the torque which turns the cutterhead in its operation of dredging the bottom of waterways. The cutterhead encounters all kinds of material, including rock, which must be removed.
For the purpose of digging in rocky ground the cutterhead is fitted with teeth of high hardness and high impact properties;for the purpose of digging in soft to medium-soft ground the cutterhead is provided with edges of moderate hardness welded to the leading edge of the cutterhead blades. The service life of such welded edges is not as long as that of the hard teeth. The hard teeth extend radially a substantial distance ahead of the blade and do not perform efficiently in the soft-to-medium earth. Accordingly, it is most desirable to provide a cutterhead employing teeth of high hardness and wear resistance arranged in such a manner as to be efficient for digging in soft-to-medium soils and also to provide the advantages of easily replaceable forward edges.
The most common variety of replaceable tooth for a dredge cutterhead embodies a tapered shape which is attached by an adapter to the cutterhead blade such that the point of the taper is directed at the surface which is to be cut and the longitudinal axis of the tooth, generally passes through the centroid of the cutter blade section and is generally at an angle with respect to the profile plane of the cutterhead from the point of the tooth so as to provide an efficient transmission of power to the tooth with a minimum of breaking force. A replaceable tooth assembly is disclosed in U.S. Pat. No. 4,891,893, for example.
There is, of course, always the problem of realigning the tooth in the proper direction with respect to the cutterhead and welding the tooth into a fixed realignment. A novel assembly has been developed which permits a precise alignment for replacing the adapter, regardless of whether the adapter has been worn or broken.
It is an object of this invention to provide an improved assembly for mounting an adapter onto a cutterhead. It is another object of the invention to provide a system for accurately mounting an adapter and obtaining a desired alignment without special or laborious efforts. Still other objects will appear from the more detailed description which follows.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a replaceable adapter assembly for an excavating cutterhead which includes the combination of a blade socket conically tapering from a larger open top to a smaller hemispherical bottom; an adapter having a body with a rearwardly projecting conical shaft tapering from the body to a smaller hemispherical bottom adapted to mate with the blade socket bottom, and having a forwardly projecting nose to mate with a recess in a digging tooth having a forward tip. An alignment ring is provided to fit snugly around the tapering shank adjacent to the adapter body, the adapter shank being smaller in radial size than the blade socket so as to permit a limited alignment of the tooth tip to its proper position. The alignment ring and the adapter shank have mutual indexing means to assure that a reassembly of a new adapter for a previously worn adapter into the ring can be made at exactly the same location to assure accurate location of the tooth tip.
In specific embodiments the indexing means includes mating flat spots, surfaces or notches on the adapter and the ring. In another embodiment the taper of the socket is about 5°-20° larger than the taper of the adapter shank.
In the method of this invention a welded assembly of a tooth, adapter, ring and blade socket is heated to break the weld between the adapter and the ring while leaving the welded connection between the ring and the blade socket intact. A new adapter can then replace the worn one, and the adapter aligned with the indexing spot or notch on the alignment ring and welded into place with the orientation of the tooth to the cutterhead blade automatically being the same as it was before being dissembled to accurately position the tip of the tooth on the cutterhead.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a front elevational view of an excavating cutterhead of the prior art;
FIG. 2 is a longitudinal cross-section of a schematic assembly of an adapter and a tooth onto a blade of an excavating cutterhead of the prior art;
FIG. 3 is a top plan view of the assembly of a tooth, adapter, alignment ring, and blade socket of this invention; and
FIG. 4 is a cross-sectional view taken at 4--4 of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
This invention is best understood by reference to the attached drawings.
FIGS. 1-2 show the general state of the prior art of excavating cutterheads. A cutterhead 22 is mounted on the end of a long derrick framework such that the cutterhead 20 can be rotated around a length-wise axis 22 so as to permit projecting teeth 24 to dig into the ground (frequently underwater). Each tooth 24 is seated in an adapter 23 which, in turn, is mounted (usually by welding) onto a blade 21 of cutterhead 20. Several helical blades 21 extend from a central forward hub 25 to a rearward outer ring 26. Each tooth 24 is oriented in an individual direction by means of the orientation of the adapter when it is positioned and attached to a blade 21.
In general, an adapter 2 3, shown schematically in FIG. 2, is attached to a blade 21 by welding. There may be a certain amount of latitude in the precise direction in which the longitudinal axis 46 of tooth 24 and adapter 23 is positioned with respect to blade 21, depending on the material being excavated and the direction of the cut being made by the excavating machinery. In any event, an adapter 23 is normally welded to a blade 21 of the cutterhead, and the tooth 24 is attached to the adapter 23 by way of a tongue 47 in one component fitting into a recess 48 in the other component and the resulting juncture fastened securely by a key 49. It may also be that tooth 24 and adapter 23 are welded together. When a tooth 24 and/or an adapter 23 are worn, broken, or for other reason need to be replaced, it is a time-consuming job to melt the welds, remove the key, replace the necessary pieces, and reassemble the combination, being careful to orient the combination in the desired direction each time a replacement is needed. The present invention facilitates the job considerably by eliminating the reorientation step.
In FIGS. 3-4 there is shown a novel combination of a tooth 33, an adapter 29, an alignment or adjustment collar or ring 41, and a blade socket 27. Blade socket 27 may be a component manufactured separate from the blade 21 (see FIG. 1) and later attached by welding or the blade can be manufactured originally with a plurality of sockets therein. The principal feature of blade socket 27 is a hemispherical socket or recess 28 which flares outwardly in a tapering or conical shape 36 to an opening. This hemispherical recess 28 forms a seat for a hemispherical bottom 31 on shank 30 which depends downwardly from the main central body of adapter 29. Hemispherical recess 28 and hemispherical bottom 31 preferably are geometrically identical so as to exactly conform or mate with each other, although some leeway is permissible in permitting hemispherical bottom 31 to be slightly smaller in radius than hemispherical recess, since it is necessary for bottom 31 to be rotatable in recess 28. The more snugly the fit between hemispherical bottom 31 and recess 28 the better will be the ability of the entire assembly to absorb the shocks and stresses of the excavation without breakage of teeth and adapters.
Each adapter 29 has a central body with a rearwardly projecting shank 30 and a forwardly projecting nose 32. Nose 32 is made to be the male portion of mating a fit with a corresponding recess in tooth 33. No particular shape is required. Passing completely through tooth 33 and adapter 29 is a keyway 40 to admit a key 55 to provide a firm connection between these two cooperating components. In the embodiment shown in FIGS. 3 and 4 the tooth 33 has depending flanges 34 which fit snugly into sockets 35 on the adapter 29.
The rearward end of adapter 29 is a tapering, conical shank 30 converging from a larger diameter at the central body of adapter 29 to a smaller diameter at hemispherical bottom 31. This arrangement then results in a smaller body of shank 30 inside a larger recess 36 leaving an annular space 50 which, in turn, provides some possibility of orienting tooth tip 38 throughout a circular adjustment zone 39. The respective sizes of shank 37 and recess 36 will dictate the size of zone 39. Generally, the included apex angle of recess 36 should be about 5-°20° larger than the included apex angle of shank 30.
Alignment collar or adjustment ring 41 is an annular ring having an inside conical surface to approximately match the outside conical surface of adapter shank 30. Collar 41 should be of a size to fit snugly against the outwardly flaring shoulder 54. The exact shape of the outside surfaces of collar 41 are not critical, but generally are shaped so as to provide a generous V-notch desirable for making a good weld since there is to be a weld 42 between the adapter 29 and the collar 41, and a weld 43 between the collar 41 and the blade socket 27. The upper face of adjustment ring 41 in contact with the adjacent face of adapter 23 makes a contact angle of 20°-α° ; and the lower face of adjustment ring 41 makes a contact angle of 20°-60° with the adjacent surface of the open top of the blade socket 27, as seen mast clearly in FIG. 4. On each collar 41 and adapter 29 there is an indexing means 44, 45 that mutually cooperate to provide a readily recognizable means for aligning these two components. The means normally are mating physical features, e.g., flat spots, notches, or the like, that can be mated by feel just prior to welding.
In operation when first assembling cutterhead blade sockets 27 are welded to cutterhead blades at approximate positions and pointed in approximate directions. Precision is not absolutely necessary, although reasonable care is taken to achieve approximate directions. The combination of an adapter 29 and an alignment collar 41 is then precisely oriented in the desired direction and welds 42 and 43 made to put these components in a firm connection to the cutterhead. Tooth 33 can then be attached by means of a key (not shown) through keyway 40.
When an adapter 29 wears out or becomes broken and must be replaced, weld 42 is burned out to permit the old adapter 29 to be removed and replaced by a new adapter. Weld 43 is not broken but remains in place connecting collar 41 to blade socket 27. The new adapter 29 can be rotated to find the appropriate location where the indexing means 44, 45 (flat spot or notch) meet, and weld 42 can immediately be filled in without further concern about orientation, because the original orientation remains in place between collar 41 and blade socket 27. This innovation saves considerable down time that would otherwise be spent making sure the replacement adapter 29 is properly oriented.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | An adapter assembly for an excavating cutterhead comprising the combination of a blade socket with a hemispherical recess, an adapter with a hemispherical-bottomed shaft to fit in the socket, and a mounting ring around the adapter head which can be indexed with respect to each other such that the adapter may be precisely replaced in an operating assembly without need to reorient the entire assembly. This is accomplished by means of mutually indexing each of the adapter and the mounting ring prior to the initial orientation of the assembly. | 4 |
This invention relates generally to seals between rotating and stationary machine components and specifically, to a leaf seal assembly between a stator and a turbine rotor. This invention was made with Government support under Contract No. DE-FC21-95MC31176 awarded by the Department of Energy. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Gas turbine operation depends upon the controlled flow of air between rotating and static components. Seals are introduced between these components in order to direct the flow in the desired paths. For example, it may be desirable in some cases to prevent flow in some directions, such as into bearing housings, while in other cases, it may be desirable to direct a controlled amount of flow to actively purge cavities, cool components, and prevent hot flowpath gases from contacting rotor components. Examples of this latter type of seal may be found in the compressor discharge secondary flow circuit and in the paths around the turbine nozzle diaphragms. Establishing a seal that provides a controlled amount of leakage, independent of operating condition, thermal transients, and operating age, has been an ongoing design objective.
A number of different seal designs have been used in the gas turbine industry. These include: “pumpkin teeth” seals; labyrinth seals; honeycomb seals; and brush seals. All of these designs are intended to provide a “tortuous” path for the air and thus minimize the leakage across them. Table I describes the prior seals, qualitatively comparing them based on certain key features:
TABLE I
PUMP-
HONEY-
FEATURE
KIN
LABYRINTH
COMB
BRUSH
rotor stator contact
no
possible
yes
yes
deterioration w/ usage
no
if contact
yes
slight
adapts to transients,
no
no
no
yes
operating points
relative leakage flow
high
lower (because of
lower still
very
lower clearances)
low
“windage” temperature
slight
slight
higher
lower
rise of leakage air
adapts to casing non-
no
no
no
yes
symmetry
Note that in many applications, some minimum level of air leakage is required to ensure cavity purge flow high enough to preclude contact of rotor structural components with hot gaspath gasses. For this reason, holes allowing air to bypass the seal may be included with brush or honeycomb seals. One difficulty with this approach, however, is that to ensure safe operation, the holes must be sized to provide sufficient flow based a new seal configuration. If the seal later deteriorates, and leaks more flow than when new, the total flow past the seal will be greater than design requirements.
BRIEF SUMMARY OF THE INVENTION
The present invention utilizes a circumferential array of leaf seals clamped (or otherwise fixed) into the stator component. In the preferred embodiment, the individual leaf seal components or segments each comprise a primary spring and a backing spring, each attached to the stator. The primary spring has an attachment portion and a seal portion that extends generally axially along the rotor, curving toward and then away from the rotor surface in the flow direction. The backing spring also has an attachment portion and a more sharply curved backing portion that engages substantially tangentially the backside of the primary spring. The backing spring serves two purposes:
1. Because of its different curvature and possibly different thickness, the effective stiffness of the two springs together will be non-linear (i.e.: the load-deflection curve will be a curve, not a straight line). This will allow the seal opening, and thus performance, to be optimized over a greater range of operating conditions.
2. Since the two springs will rub against each other, they will serve as friction dampers for each other, preventing vibration and fatigue that might result from aerodynamic instabilities or flutter of the seal.
The collective array of leaf seal segments are circumferentially overlapped or shingled, requiring the backing springs to be slightly shorter in tangential length than the primary springs. The primary springs are assembled with a slight radial gap relative to the rotor when the machine is not in operation. When the machine is started, a pressure differential develops across the seal, with the higher upstream pressure trying to push the seal open. The force pushing the seal open will be based upon the difference between the total upstream pressure and the total downstream pressure. As soon as fluid flow past the seal begins, however, the force will drop. This is because the air attains a velocity and the force depends upon the difference between the static upstream and downstream pressures. The downstream velocity will be low, so this static pressure will approximate the total pressure, but the upstream static pressure (opening force) will drop by an amount proportional to the flow rate/velocity.
Since the force opening the seal decreases as the flow rate/velocity increases, and the spring force closing the seal increases with the seal opening, the seal can be designed to allow a controlled “leakage” for any given design point.
Accordingly, in one aspect, the invention relates to a seal assembly for installation between rotating and stationary components of a machine comprising a first plurality of leaf spring segments secured to the stationary component in a circumferential array surrounding the rotating component, the leaf spring segments each having a radial mounting portion and a substantially axial sealing portion, the plurality of leaf spring segments being shingled in a circumferential direction.
In another aspect, the invention relates to a turbine rotor and stator arrangement including a leaf spring seal assembly comprising a rotor; a stator surrounding the rotor in radially spaced relation thereto; and a leaf spring seal between the rotor and the stator, the leaf spring seal including a first plurality of leaf spring segments fixed to the stator in a circumferential array about the rotor, the leaf spring segments being circumferentially shingled, and each having a sealing portion defining a predetermined radial gap between the sealing portion and the rotor when the rotor is at rest.
In still another aspect, the invention relates to a method of sealing a radial gap between a rotor and a stator comprising: a) mounting a first plurality of leaf spring segments to the stator; and b) arranging the first plurality of leaf spring segments in a circumferentially shingled array about the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side section of leaf seal components between a stator and rotor in accordance with an exemplary embodiment of the invention; and
FIG. 2 is a schematic end view illustrating the manner in which the leaf seal components are shingled or overlapped in a circumferential direction.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, a rotor 10 and stator 12 are illustrated schematically, with a radial gap 14 therebetween. In a gas turbine environment, air flow in the direction indicated by arrow 16 is controlled by a leaf spring seal assembly 18 . The seal assembly 18 comprises individual leaf seal components or segments that are arranged circumferentially about the rotor 10 in a “shingled” or overlapped arrangement best seen in FIG. 2 . The controlled flow is desired to, for example, actively purge cavities while cooling components and preventing hot flowpath gases from contacting rotor components, e.g., in compressor discharge secondary flow circuits and in paths around the turbine nozzle diaphragms.
Each individual leaf seal component or segment includes a primary leaf spring segment 20 with a mounting portion 22 and a sealing portion 24 . The former is attached to the stator 12 by any suitable means (e.g. mechanically clamped or otherwise suitably fixed to the stator), while the sealing portion curves in an axial direction toward then away from the rotor, in a direction of flow, with a minimum radial gap at 26 . The primary spring segment 20 is substantially flat in a tangential direction, i.e., as viewed in FIG. 2, noting that each leaf seal segment is oriented generally tangentially with respect to the surface 28 of the rotor. The extent of the leaf seal segment in the tangential direction is referred to herein as its tangential length.
Each leaf seal segment also includes a secondary or backing leaf spring segment 30 , also attached to the stator 12 in a similar fashion. The backing spring segment 30 is located behind or downstream of the primary spring with a more sharply curved portion 32 engaging the backside of the primary spring in a generally tangential fashion.
Referring to FIG. 2, it will be apparent that in order to overlap or shingle the individual leaf seal assemblies without interference, the backing spring segments 30 will have a shorter tangential length than the primary springs. Nevertheless, the backing spring will be centered on the primary spring as shown in phantom in FIG. 2 .
Both the primary and secondary spring segments 20 , 30 are preferably constructed of spring steel, the specified alloy composition and the thickness of each dependent on the application. The tangential length of the primary springs will depend on the number of segments employed, which is again, application specific. It will be appreciated that the respective effective stiffnesses of spring segments 20 , 30 may vary based on different degrees of curvature, different thicknesses and different alloys. This means that the spring stiffness will be non-linear, thus permitting seal opening and thus performance to be optimized over a wide range of operating conditions.
A further advantage to the leaf spring seal consisting of chordal segments shingled over each other is that non-symmetry of the casing can be accommodated, as the different segments may self-adjust to different deflections to maintain a consistent clearance.
Prior to starting the machine, the primary spring segments 20 should be assembled with a slight gap (at 26 ) from the rotor surface. At this time, P1 (pressure upstream of the seal 18 )=P2 (pressure downstream of the seal 18 )=P3 (pressure at the radial gap 26 ). When the machine is started, P1 will increase more than will P2. In the potential application illustrated (the high pressure packing seal of a particular machine) the pressure across the seal 18 will approach 2:1 at full speed/full load, resulting in choked flow across the seal. At low P1/P2, the flow across the seal assembly 18 will be low, and so the flow velocity will be low, as will the opening force. As P1/P2 increases, the Mach number of flow across the seal will also increase, and the ratio of P1/P3 will decrease. While P3 will still be greater than is P2, it will not be as much above it as is P1, so there will be a reduced force opening the seal. This will be countered by the spring force exerted by both the primary spring segments 20 and backing spring segments 30 closing the gap 26 . Thus, the flow will be controlled by P1/P2 and the designed opening of the seal at operating conditions. Thus, the seal gap 26 and leakage adapt themselves to the operating conditions. Again, the backing spring segments 30 will preclude any instability as the seal adjusts.
Typically, the rotor 10 and the stator 12 will have different transient responses to changes in the operating conditions of the machine. At startup, the rotor 10 will rotate in the direction of arrow 34 , and may grow rapidly towards the stator 12 , due to centrifugal loading. Subsequent to that, the stator 12 will typically respond thermally more quickly than will the rotor 10 , and grow away from the rotor, which will subsequently make up some of that gap. As the machine is shut down, the process will be reversed. The pressure ratio across the seal assembly 18 will be largely independent of the thermal transient changes, and so the opening force, and the seal gap 26 will adapt to those changes. As the gap 26 follows the opening forces, however, the spring forces will act to counter those force changes, thus minimizing flow variations.
The surfaces of the primary spring segments 20 and backing spring segments 30 are all smooth, so there will be very little windage-induced temperature increase. Since there is no contact between the seal assembly 18 and the surface of the rotor 10 , there will be little if any deterioration of the seal.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A seal assembly for installation between rotating and stationary components of a machine includes a first plurality of leaf spring segments secured to the stationary component in a circumferential array surrounding the rotating component, the leaf spring segments each having a radial mounting portion and a substantially axial sealing portion, the plurality of leaf spring segments shingled in a circumferential direction. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to devices for removal of nail polish and similar coatings from the nails and particularly to devices containing an apertured absorbent member wetted with a liquid nail polish removal solvent for receiving at least one finger into contact with the absorbent member to remove polish from the nail.
2. Description of the Prior Art
The coating of the nails for decorative and protective purposes has long been practiced, such coatings typically being applied as liquids which rapidly dry to form a solid coating on the nail. Presently available nail coatings are generally known as nail "polish" and have reached a state of development whereby the polish coating can be rapidly applied by means of a brush or similar implement and which rapidly dry to form a durable covering for the nail. Even though presently available nail polish coatings are durable as well as decorative, these coatings remain subject to chipping, peeling or similar marring after a certain period of use and must be removed for application of a fresh coating of polish when damage to the coating occurs. Nail polish is also removed even though not damaged in order to match nail polish color to a wardrobe change or to a change in personal mood. For these reasons, it becomes necessary for a user of nail polish to remove polish to allow application of a fresh polish coating as frequently as one or more times daily and almost invariably on the order of two to three times weekly. The most commonly used method for removing nail polish involves the relatively time consuming and messy practice of soaking a cotton pad or tissue with a liquid nail polish removal solvent, this solvent typically being available in a pre-packaged bottle such as is commonly marketed at retail. According to this commonly used prior practice, nail polish is removed from each nail individually by contacting the wetted piece of absorbent material with the coated nail until the polish coating softens and at least partially dissolves. The wetted material is also moved over the nail to mechanically assist in the dissolution and removal of the polish from the nail. Accordingly, it can be seen that this prior practice involves a substantial amount of time and, due to the necessity for wetting an absorbent piece of material with a liquid contained within a bottle, the liquid solvent is subject to spillage with attendant risk of soiling clothing, furnishings and the like. The prior practice further involves a certain degree of messiness which can prove objectionable due to the fact that wet absorbent material must be handled and dissolved nail polish can be smeared upon the hands and fingers as well as on clothing and furnishings unless diligence is exercised to prevent such occurrences.
The desirability of providing an improved method for removal of nail polish from the nails has long been recognized in the art as is clearly shown by the nail polish removal devices disclosed by Roosa and Merrit, respectively, in U.S. Pat. Nos. 2,524,681 and 2,629,124. According to the disclosures of these patents, receptacles having a supply of liquid nail polish removal solvent contained therein are fitted with brush-like elements disposed adjacent to or within the body of the liquid solvent. A user of a device such as is disclosed by Roosa or Merrit inserts each finger individually into the receptacle through a closable opening to contact the polish-bearing nail with the liquid solvent in order to soften or dissolve the polish, the brush-like element being used to mechanically abrade the softened polish coating for more rapid loosening thereof. While devices such as those disclosed by Roosa and Merrit do serve to facilitate removal of nail polish from the nails, certain objections to the use of these devices exist. In particular, a free-standing body of liquid solvent is contained within these devices and is subject to spillage or splatter. Further, the body of liquid solvent becomes rapidly colored and otherwise contaminated with polish after only a few uses, thereby rendering the devices less attractive to a user. Users of such devices often object to the pricking of the skin caused by the bristles of the bursh-like element contained within these devices. For reasons such as those noted, devices such as those disclosed by Roosa and Merrit have not come into general use.
U.S. Pat. No. 2,961,682 to Wurmbock et al is exemplary of the further development of manicuring devices intended for personal use in the removal of polish and other coatings from the nails. As disclosed by Wurmbock et al an absorbent member saturated with nail polish remover is held within a container having a closable opening, the absorbent member being provided with a finger-receiving aperture into which at least the distal phalanx of each finger is received one at a time. The coated nail on each finger is thus brought into contact with the polish removing solvent carried by the absorbent member, the solvent acting to soften or dissolve the polish coating from the nail. Mechanical abrasion provided by the absorbent member facilitates removal of polish from the nail. Duseppe, in U.S. Pat. No. 4,282,891, provides a nail polish removal device which is essentially identical in structure and method of use to the device of Wurmbock et al. Duseppe utilizes a foam-like plastic material of fine, high density cellular structure as the absorbent member and which is substantially identical in function to the absorbent member of Wurmbock et al. The devices of both Wurmbock et al and Duseppe provide finger-receiving apertures in their respective absorbent members which extend only partially through the absorbent members. The devices of Wurmbock et al and Duseppe are also utilized by practice of an identical method of use, that is, by insertion of each finger into the finger-receiving aperture of the absorbent members to remove polish from each nail. The devices of Roosa and Merrit described above are also utilized by a substantially identical method of use. While nail polish removal devices such as are disclosed by Wurmbock et al and Duseppe provide improvement over the devices of Roosa and Merrit, it is to be noted that a certain degree of use of the Wurmbock et al and Duseppe devices results in a coloring of the liquid solvent contained within the receptacle which holds the absorbent member. While the liquid solvent retains its polish removal capabilities well beyond that point at which the liquid solvent becomes colored, a user of such a device begins to view the device as being contaminated and typically prefers to discard the device prior to the end of the useful life of the device. The actual useful lifetime of such devices are therefore considerably foreshortened unnecessarily due to this "contamination" caused by the accumulation of dissolved polish within the device. In the devices of Wurmbock et al and Duseppe, as well as in those similar nail polish removal devices presently marketed, the user of the device is unable to remove the absorbent member from the receptacle for cleaning since such removal results in the loss of all of the liquid solvent within the receptacle, there being no self-contained capability provided with such devices for replenishment of liquid solvent to the device.
The present invention provides self-contained structure including structure useful in the manner of a fingernail polish removal device and which is provided with a substantially integral supply container which enables the recharging of the nail polish removal device with fresh liquid solvent as is necessary according to use of the device. The present invention thus provides to a user the temporal and handling advantages characteristic of presently available fingernail polish removal devices and further provides the capability of replenishing used liquid solvent, thereby extending the useful life of a nail polish removal device. Substantial advantages over the prior art are thus provided by the present invention, these advantages being of a nature not foreseen in the long history of the search for improvement in the manner by which nail coatings are removed from the nails.
SUMMARY OF THE INVENTION
The invention particularly provides devices for treating the fingernails such as by removal of fingernail polish from the nails. In all embodiments of the present invention, nail polish removal devices are provided which include a nail treatment container having an absorbent member disposed therein which is wetted with a liquid nail polish removal solvent and which has at least one aperture for receiving a finger thereinto for contact between a polish coated nail and the liquid solvent absorbed into the absorbent member. The several embodiments of the invention further include a supply container on which the treatment container can be carried, the supply container holding a supply of liquid nail polish removal solvent sufficient to recharge the treatment container a multiple number of times. The supply container can particularly be formed of glass in order to eliminate evaporation of the liquid solvent therefrom, a condition which typically occurs to at least some degree from the plastic materials from which nail polish removal devices are typically formed. Particular embodiments of the invention provide a valved cap element which closes the supply container and which typically carries the treatment container, the interior of the supply container communicating with the interior of the treatment container through the valved cap element to allow controlled charging of liquid solvent from the supply container into the treatment container when replenishment of the liquid solvent within the treatment container is required. Liquid nail polish removal solvent is thus stored within the supply container with essentially no loss of the solvent and is then dispensed as desired into the treatment container such as after cleaning of the absorbent member to remove used liquid solvent therefrom.
The present structures provide particular advantages over the nail polish removal devices of the prior art as noted herein and over reservoir bottle structures such as are disclosed by Williams et al in U.S. Pat. No. 1,034,177 and Rosenstein in U.S. Pat. No. 1,098,976. Williams et al describes a bottle having a cap which mounts a reservoir for nail polish, the reservoir being in turn covered by a second cap element bearing a buffer pad. Rosenstein describes a bottle cap having a bleed hole which is adapted to feed the contents of a bottle dauber element carried by the cap, thereby to allow application of the contents of the bottle to a surface which is to be coated with polish, paint or the like. These prior structures do not provide the particular structures of the present invention nor does this prior art function in the manner of the embodiments of the present invention. In contradistinction to the prior art, the embodiments of the present invention provide self-contained nail polish removal devices having a treatment portion thereof capable of removing nail polish from the nails in a rapid and clean fashion while allowing replenishment of liquid nail polish removal solvent from a supply portion of the devices on cleaning of an absorbent element which forms a primary portion of the treatment portion of the devices. The absorbent element of the treatment portion of the devices can thus be cleaned without concern for the total loss of all liquid solvent from the self-contained device. Further, due to the ability to form the supply portion of the self-contained devices of the invention from a material such as glass and to also form the supply portion with a relatively smaller diameter opening than is possible with the nail treatment devices of the prior art, loss of liquid solvent through the walls of the devices as well as through closable openings thereof is substantially reduced.
It is accordingly an object of the present invention to provide nail polish removal devices having treatment portions and liquid solvent supply portions whereby the treatment portion can be replenished with liquid solvent as necessary.
It is another object of the present invention to provide self-contained nail polish removal devices wherein a liquid solvent supply container is closed and surmounted by a treatment container, the interior of the supply container communicating with the interior of the treatment container through a valve element located between said containers and particularly in a cap element closing the supply container, thereby to allow liquid nail polish removal solvent stored within the supply container to be dispensed as required into the treatment container.
It is a further object of the present invention to provide nail polish removal devices for treatment of the nails to remove polish coatings therefrom and which include a self-contained supply of nail polish removal solvent, the structure of the self-contained devices acting to reduce loss of the liquid solvent by evaporation through walls and openings of the devices.
Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a particular embodiment of the present invention;
FIG. 2 is an exploded view illustrating the various components which comprise a first embodiment of the invention;
FIG. 3 is an elevational view in section of a particular embodiment of the invention such as is seen in FIG. 2;
FIG. 4 is a detailed view taken in section along line 4--4 of FIG. 3;
FIG. 5 is a detailed elevational view in section illustrating an annular ridge element which acts to hold an absorbent element within a treatment portion of the present devices;
FIG. 6 is a perspective view in section illustrating the use of a retainer element for retaining absorbent members within the treatment portions of the present devices;
FIG. 7a is an elevational view in section illustrating a metering valve used as an exemplary embodiment of the invention;
FIG. 7b is a section taken along line 7b--7b of FIG. 7a;
FIG. 8 is an elevational view in section illustrating a further embodiment of the invention; and
FIG. 9 is an elevational view in section illustrating a still further embodiment of the invention whereby the structure does not provide communication between a supply portion and a treatment portion of the structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and particularly to FIGS. 1-4, a nail polish removal device configured according to a first embodiment of the invention is seen generally at 10 to comprise a nail treatment container 12 and a supply container 14. The treatment container 12 is seen to generally take the form of a cylinder open at its upper end and being closable at opening 16 by means of a threaded lid 18. The treatment container 12 has an absorbent member 20 disposed therein, the absorbent member 20 being similarly shaped in the form of a cylinder and having a central aperture 22 formed therein, the aperture 22 preferably extending essentially throughout the height of the absorbent member from exposed face 24 to the opposite face of said absorbent member. The absorbent member 20 is impregnated or otherwise wetted with a liquid nail polish removal solvent which contacts a nail of a finger when the distal phalanx of said finger is inserted into the aperture 22 of the absorbent member 20. The softening and solvating action of the liquid solvent acts to loosen a polish coating from a nail thus received within the aperture 22, the mechanical action of the walls of the aperture 22 further facilitating the removal of the polish coating from the nail.
The absorbent member 20 is preferably formed of a high density cellular foam material such as polyurethane or similar "plastic" and such as is employed in presently available commercial nail polish removal devices such as that device marketed under the trademark "Just Dip" of Cameo, Inc., of Toledo, Ohio. A similar material is described in U.S. Pat. No. 4,282,891 and is also seen to be generally suitable for formation of the absorbent member 20. The aperture 22 in the absorbent member 20 can be formed either as a cylindrical channel extending throughout the absorbent member 20 or as one or more slits which effectively form an aperture within the absorbent member 20. In the event that more than one slit is used to form the aperture 22, the slits preferably intersect medially of the lengths thereof.
The treatment container 12 can be closed by disposition of the threaded lid 18 over the opening 16, the opening 16 having mating threads formed thereabout to engage the threads of the lid 18 in a known manner such that the treatment container 12 can be closed when not in use. Evaporation of the liquid solvent through the opening 16 is thereby reduced and leakage or spillage of the liquid solvent from the container 12 is prevented. In structure and intended operation, the treatment container 12 is thus seen to be similar to commercially available nail treatment devices such as the "Just Dip" device referred to above and such as is generally disclosed in U.S. Pat. No. 4,282,891. The liquid solvent used in the treatment container 12 can take a variety of known forms and is typically chosen to be a solution of acetone and selected conditioning substances. However, the treatment container 12 is seen to effectively surmount and cooperate with the supply container 14 which holds a given quantity of the liquid solvent in storage separate from the liquid solvent which is being used at any given time within the treatment container 12. The supply container 14 is preferably chosen to comprise a container formed of glass or similar material which is impervious to the liquid solvent and is capable of storing said solvent without evaporative loss through the walls of the container 14. The supply container 14 can be chosen as shown in FIGS. 1-4 to have a relatively large base compared to the diameter of the treatment container 12 such that the device 10 is resistant to being accidentally tipped over or otherwise caused to become imbalanced. The supply container 14 stores a quantity of liquid solvent sufficient to allow multiple recharging of the treatment container 12 when the liquid solvent within the treatment container 12 has become sufficiently contaminated to warrant cleaning of the absorbent member 20 and removal of used liquid solvent from the container 12.
As particularly seen in FIGS. 1-4, the treatment container 12 is integrally formed with and surmounts a lowermost cap portion 26, the cap portion 26 being internally threaded at 28 to allow positive closure of opening 30 on neck 32 of the supply container 14. The neck 32 is seen to be formed with external threads 34 which mate with the internally threaded cap portion 26 to secure the treatment container 12 to the supply container 14. It is to be noted that the opening 30 of the supply container 14 has a smaller diameter than that of the opening 16 of the treatment container 12, this reduced diameter of the opening 30 resulting in a somewhat lower liquid solvent loss from an open supply container 14 than is experienced from an open treatment container 12. In the prior art, nail polish removal devices contain the total amount of liquid solvent within a wide-mouthed container and thus lose a given amount of solvent by evaporation when such devices are opened and particularly when such devices are allowed to remain open for substantial periods of time. In the present nail polish removal device 10, the maintenance of a substantial portion of the liquid solvent within the supply container 14 having a reduced opening 30 results in lower loss of solvent through said opening 30 as compared to losses through openings of prior devices and even through the opening 16 of the treatment container 12. Since the present nail polish removal device 10 is capable of maintaining a substantial supply of liquid solvent within the supply container 14, the treatment container 12 can be made smaller than is the case with prior art nail polish removal devices since the treatment container 12 does not have to be sufficiently large to contain substantial quantities of liquid solvent sufficient for use over a relatively long period of time. Through use of the present device 10, relatively smaller quantities of liquid solvent can be contained within the treatment container 12 and used until effectively spent, the absorbent member 20 then being removed from the treatment container 12 and cleaned and the spent liquid solvent discarded, the supply of liquid solvent then being replenished into the treatment container 12 from the supply container 14. The treatment container 12 and absorbent member 20 can thus be of a relatively small size which results in material savings.
The nail polish removal device 10 is further configured such that the treatment container 12 can be replenished with liquid solvent from the supply container 14 without removal of the cap portion 26 (and thus the treatment container 12) from surmounting relation with and connection to the supply container 14. Liquid solvent replenishment is preferably accomplished by disposition of a valve 36 in the cap portion 26 which communicates the interior of the treatment container 12 with the interior of the supply container 14. The valve 36 is seen to comprise an aperture 38 formed in the lower portion of a valve stem 40, the aperture 38 communicating the interior of the treatment container 12 through the cylindrical valve stem 40 with the interior of the supply container 14. The stem 40 is seen to extend into the interior of the treatment container 12 a distance which is chosen to be greater than the depth of the liquid solvent which is contained within the treatment container 12. The extension of the upper end 42 of the stem 40 above the level of the liquid solvent within the container 12 prevents flow of the liquid solvent back into the supply container 14. A cap 43 can be disposed over the end 42 to prevent backflow through the end 42. The valve stem 40 is offset from the longitudinal axis of the container 12 in order that the aperture 22 in the absorbent member 20 can be centrally disposed for receiving at least the distal phalanx of a finger thereinto for removal of polish from a nail. An offset aperture 44 is conveniently provided in the absorbent member 20 to receive the valve stem 40, the offset aperture 44 extending from the lower unexposed face of the absorbent member 20 and terminating at a point within the body of the absorbent 20 such that the aperture 44 does not exit the absorbent member 20 on the exposed face 24 thereof. The offset of the aperture 38 and valve stem 40 from the longitudinal axis of the container 12 is chosen to be sufficient to avoid contact between the elevated valve stem 40 and a finger inserted into the aperture 22 of the absorbent 20 while maintaining the aperture 38 and thus the interior lumen of the stem 40 in communication with the supply container 14 through the opening 30 of said container 14.
While the valve 36 can take a variety of forms, a ball valve structure is conveniently utilized due to the effectiveness of such a valve and due also to manufacturing economy and simplicity of operation. The valve 36 is thus seen to contain a captive ball element 46 which is maintained within the valve stem 40 by means of an annular stop element 48 disposed at the lower portion of the stem 40 and by the cap 43 at the upper end of the stem 40. The ball element 46 is seen to close the aperture 38 when the device 10 is in a vertical position with the treatment container 12 surmounting the supply container 14. In this position, liquid solvent remains within the supply container 14 and the container 14 is effectively closed from communication with the treatment container 12 by means of the seating of the ball element 46 against the lower annular stop element 48. On inversion of the device 10, the ball element 46 is displaced against the cap 43 disposed over the end 42 of the valve stem 40, thereby allowing liquid solvent from the supply container to flow through side apertures 52 formed in the walls of the valve stem adjacent the floor of the treatment container 12. The side apertures 52 thus allow flow of liquid solvent through the aperture 38 and discharge of the liquid solvent from the valve stem 40 to the interior of the treatment container 12. It is to be recognized that charging of the treatment container 12 thus described with liquid solvent from the supply container 14 occurs as a result of the inversion of the device 10 such that the supply container 14 surmounts the treatment container 12 when the container 12 is being replenished with liquid solvent. During this replenishment process, the lid 18 is secured over the opening 16 of the treatment container 12 to prevent loss of liquid solvent through the opening 16. In order to charge a desired quantity of liquid solvent into the treatment container 12 on inversion of the device 10, the rate of liquid solvent flow through the side apertures 52 is gauged according to the dimensions of the aperture 38 and of the side apertures 52 such that the device 10 is inverted for a predetermined period of time, for example, for a period of approximately 5 seconds, such that a sufficient quantity of liquid solvent is caused to flow through the valve 36 and into the interior of the treatment container 12. The orientation of the device 10 is then returned to the "normal" or non-charging position such that the treatment container 12 again surmounts the supply container 14. The treatment container 12 is thus replenished with liquid solvent from the supply container 14 in a simple and rapid operation which does not require the removal of the cap portion 26 from engagement with the supply container 14.
While the absorbent members useful with the invention expand when wetted with liquid solvent and thus act due to this expansion to form a friction fit within a treatment container, additional retaining structure can be provided within a treatment container 50 of FIG. 5 to further prevent accidental or unintentional dislodgement of the absorbent member 20 from the interior of the container 50. The container 50 is essentially identical to the container 12 of FIGS. 1-4. An annular ridge 54 can be seen to be formed about interior side walls of the container 50 immediately above and adjacent to absorbent member 51 in order to maintain said member 51 within the container 50. Alternatively, the treatment container 50 can be configured to provide an enclosed chamber having a shoulder portion at the upper portions thereof which effectively reduces the diameter of the opening of the container 50, such an opening being of a diameter less than the diameter of the essentially cylindrical absorbent member 51 to provide an additional capability for retention of the absorbent member 51 within the container 50.
FIG. 6 illustrates the use of a retainer plate 56 which can be disposed over an opening in a treatment container 59 such that the retainer plate 56 is removably mounted in surmounting relation to an absorbent member 57. An annular bead 58 formed on side walls of treatment container 59 allows the plate 56 to be snap-fit into the container 59 and to allow removal thereof when it is desired to clean the absorbent member 57. The retainer plate 56 is seen to be formed with a central aperture 60 which allows a finger to be received therethrough and into an aperture 61 formed in the absorbent member 57. The aperture 60 can further serve as a guide for directing the finger into the aperture 61 formed in the absorbent member 57.
Referring now to FIGS. 7a and 7b, a treatment container 62 is seen to be provided with a metering valve arrangement seen generally at 63. In operation, the treatment container 62 and associated supply container (not shown) are inverted and the liquid solvent flows into inner liquid chamber 64 through opening 65 in floor 66 of the container 62. The air in the inner chamber 64 displaced by the liquid solvent is conveyed into the interior of the supply container (not shown) through chambers 67 and 68 and opening 69 of siphon tube 70. The liquid solvent continues to rise in the liquid chamber 64 while the treatment container 62 and associated supply container are inverted. When the liquid solvent pouring into the inner liquid chamber 64 rises above the level of dispensing tube 71, automatic siphon flow is established and liquid is drawn upwardly between the tube 71 and the siphon tube 70 and outwardly through the dispensing tube 71 until the liquid level drops below the rim of the siphon tube 70 whereupon flow ceases and the liquid level in the liquid chamber 64 again begins to rise for repetition of the dispensing cycle. Once the level of liquid solvent within the treatment container 62 has reached a predetermined level, such as through one or more filling cycles, flotation ball 72 floats upwardly (given that the treatment container 62 and associated supply container remain inverted) to seat against stop element 76 and thus block apertures 73 formed in the dispensing tube 71. During filling of the treatment container 62, the liquid solvent flows through the apertures 73 formed near distal end 74 of the tube 71. Vent tube 75 acts to communicate the inner liquid chamber 64 with the "ambient atmosphere" represented by the interior of the treatment container 62, thereby allowing a venting necessary to maintenance of flow through the dispensing tube 71. The dispensing tube 71 and the vent tube 75 are offset from the longitudinal axis of the substantially cylindrical treatment container 62 to allow formation of finger receiving recess 80 in absorbent member 81, the tubes 71 and 75 being received into apertures formed in the absorbent member 81 in a manner similar to that referred to hereinabove. The outermost ends of the dispensing tube 71 and vent tube 75 extend a distance which is sufficient to cause said ends to be above the normal level of liquid solvent within the treatment container 62.
A predetermined quantity of liquid solvent is thus dispensed into the treatment container 62 from associated supply container (not shown) through the metering valve arrangement 63. It is to be understood that the flotation ball 72 need not be utilized in the event that it is desired to simply invert the device for a predetermined period of time or a predetermined number of cycles. It is also to be understood that the treatment container 62 is formed with a cap portion 78 having threads 77 which mate with threads on a supply container as is shown hereinabove. A threaded lid 79 is also affixed to the treatment container 62 as is described above and as is conventional in the art.
The metering arrangement 63 can typically take the form of that liquid dispensing valve arrangement described in U.S. Pat. No. 3,220,618, the disclosure of which is incorporated hereinto by reference. Further, a number of siphon flow metering valve arrangements are described in the prior art which can be readily adapted for use with the present structure. In particular, the metering valve arrangements of the following patents can be utilized herewith, the disclosures of the U.S. Pat. Nos. listed below being incorporated hereinto by reference:
1,862,801, 2,193,043, 2,208,862, 2,209,947, 2,229,122, 2,442,133, 2,546,188, 2,667,290, 2,678,757, 2,689,671, 3,081,008, 3,097,769, 3,184,106, 3,193,160, 3,254,808, 3,263,872, 3,707,247, 3,919,456, 3,968,907.
Referring now to FIG. 8, a further embodiment of the invention can be seen at 80 to comprise a nail polish removal device having a treatment container 82 which surmounts a supply container 83 through a cap element 84 which closes the supply container 83 in a manner essentially identical to the previous description of the device 10. In the device 80, however, the cap element 84 is not integral with the treatment container 82 but comprises threaded wall portions 86 which secure the cap element 84 to the supply container in a manner such as is described relative to the device 10. The cap element 84 is further seen to have an annular groove 88 formed in an upper portion thereof to receive an annular bead 90 formed on interior walls of an extended annular skirt portion 92 of the treatment container 82. The bead 90 of the treatment container 82 fits within the groove 88 of the cap element such that the treatment container 82 can be rotated relative to the cap element 84. A small amount of "play" is provided between the groove 88 and the bead 90 to accommodate movements necessary to operate the device 80. Top wall 94 of the cap element 84 is provided with an opening 96 and a blind depression 98, the opening 96 and the blind depression 98 being alignable respectively with an open tube 100 and a closed tube 102 formed on the exterior surface of bottom wall 104 of the treatment container 82. The cap element 84 can thus be rotated relative to the treatment container 82 such that either the open tube 100 or the closed tube 102 aligns with either the opening 96 or the blind depression 98 on the cap element 84. Annular beads 103 and 105 formed on upper surfaces of the top wall 94 allow snap-fitting of the tubes 100 and 102 into place. As can thus be understood, the interior of the treatment container 82 is open to the interior of the supply container 83 when the opening 96 aligns with the open tube 100. When in this position, liquid solvent can be dispensed into the treatment container 82 through the cap element 84. An absorbent member (not shown) held within the treatment container 82 can thus have liquid solvent replenished thereto as desired by inversion of the device 80 to cause liquid solvent to flow under the influence of gravity through the aligned opening 96 and the open tube 100. In this embodiment, only a central aperture needs to be formed in the absorbent member for receipt of at least a portion of the finger thereinto.
Considering now the embodiment of FIG. 9, a nail polish removal device is seen generally at 110 to comprise a treatment container 112 and a supply container 114. The supply container 114 is seen to be provided with a cap 116 which is threaded in a conventional manner to be secured to a threaded neck 118 of the supply container. The treatment container 112 is seen to be integrally formed with the cap 116 to cause the treatment container 112 to be connected to the supply container 114 in surmounting relation thereto. It can thus be seen in this embodiment that the respective interiors of the treatment container 112 and supply container 114 do not communicate through the cap 116. Replenishment of liquid solvent from the supply container 114 is accomplished by removal of the cap 116 and integral treatment container 112 from surmounting relation to the supply container 114 to allow pouring of the liquid solvent from the supply container 114 into the treatment container 112, thereby to impregnate absorbent member 120 with liquid solvent. On wetting of the absorbent member 120, and the cap 116 and the integral treatment container 112 is replaced on the supply container 114 in connected relation thereto such that the containers 112 and 114 are maintained together to prevent separation of the containers from each other, thereby maintaining a supply of liquid solvent with the treatment container to prevent separation of the liquid solvent supply from the nail treating portion of the device 110. A separate cap can be used to close the supply container 114 if desired with a collar formed integrally with the treatment container 112 being fitted over such a separate cap.
It can thus be understood that the invention can take a variety of forms including those embodiments particularly described herein. In particular, the retaining elements described above can be utilized with any of the embodiments of the invention without departing from the intent of the invention. Various other structural features may also be combined even if not shown explicitly in the drawings or described hereinabove without departing from the scope of the invention as recited in the appended claims. | A device for treating the fingernails and particularly for removal of nail polish from the nails, the invention provides a treatment container having an absorbent member disposed therein which is soaked with a liquid nail polish removal solvent, at least one finger being received within an aperture formed in the absorbent member to contact the nail with the solvent and with surfaces of the aperture to remove a polish coating from the nail. The invention particularly provides a supply container on which the treatment container can be carried, the interior of the supply container connecting with the interior of the treatment container through a valve in a cap element closing the supply container, thereby to allow liquid nail polish removal solvent stored within the supply container to be dispensed as desired into the treatment container. A user of the present device can thus replenish the supply of liquid nail polish removal solvent within the treatment container when usage of the treatment container renders a previous charge of the liquid solvent unfit for use. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of PCT Application No. PCT/JP2008/072433, filed Dec. 10, 2008, which was published under PCT Article 21(2) in Japanese.
[0002] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2007-318632, filed Dec. 10, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a condenser condensing steam into condensate with cooling water.
[0005] 2. Description of the Related Art
[0006] A condenser applied to, for example, a nuclear power plant or a thermal power plant, condenses turbine exhaust steam which has ended an expansion work by steam turbine, into condensate, with cooling water. The cooling water used in such a condenser is sea water or fresh water from a cooling tower. The cooling water is made to flow in a heat-transfer pipe arranged in the condenser to exchange heat with the exhaust steam introduced into the condenser and condense the turbine exhaust steam.
[0007] One of the types of condenser is a multistage pressure condenser which comprises a plurality of, i.e. two or three main body shells (i.e. a plurality of condensers) and in which pipes are serially arranged such that the cooling water pass through each of the main body shells at a plurality of times. In the main body shell of the multistage pressure condenser which is arranged on a slip stream side of the flow path of the cooling water, vacuum in the main body shell becomes lower due to rise of cooling water temperature. For this reason, the pressure of the turbine exhaust steam introduced into the main body shell arranged at the slip stream side of the flow path of the cooling water becomes higher.
[0008] Temperature of the condensate condensed in the condenser becomes a saturation temperature which substantially corresponds to the turbine exhaust pressure introduced into the main body shell of the condenser. Thus, in the multistage pressure condenser in which the main body shells are different in pressure, condensate temperatures of the multistage pressure condenser having, for example, three types of pressures in the main body shells are higher in order of a high pressure condenser, an intermediate pressure condenser and a low pressure condenser.
[0009] Since the condensate generated in the condenser is supplied again to the system as feed water, a higher temperature of the condensate is desirable in terms of heat efficiency. In the above-described three-shell multistage pressure condenser, it is preferable to make the condensate of a comparatively low temperature generated in the intermediate pressure condenser and the low pressure condenser close to the condensate temperature in the high pressure condenser.
[0010] FIG. 4A is a front sectional view showing a structure of a conventional multistage condenser 100 . FIG. 4B is a side sectional view showing the structure of the conventional multistage condenser 100 .
[0011] The multistage condenser 100 is constituted by connecting a high pressure condenser 1 , an intermediate pressure condenser 2 and a low pressure condenser 3 which are different in inner pressure, serially in this order.
[0012] The high pressure condenser 1 has a high pressure turbine 81 mounted on a head side, and a high pressure cooling tube bank 8 constituted by a number of heat-transfer pipes is provided inside the condenser. At a bottom portion of the high pressure condenser 1 , a high pressure hot well 6 is provided and a condensate outlet box 7 is also provided at a lower side.
[0013] The high pressure hot well 6 consists of a liquid phase part 6 a serving as the bottom portion where the condensate is stored, and a vapor phase part 6 b provided between the liquid phase part 6 a and the high pressure cooling tube bank 8 . In addition, a heater drain tube 13 is connected to the high pressure condenser 1 and a high pressure baffle 9 is provided at the connection part.
[0014] The intermediate pressure condenser 2 has a lower inner pressure than the high pressure condenser 1 , and has an intermediate pressure turbine 82 mounted on a head side. An intermediate pressure cooling tube bank 28 constituted by a number of heat-transfer pipes is provided inside the condenser, similarly to the high pressure condenser 1 . A reheat chamber 22 partitioned by a pressure shroud 4 is provided at a lower portion of the intermediate pressure cooling tube bank 28 .
[0015] In the reheat chamber 22 , a steam duct 10 serving as high pressure steam introducing means, connected to the high pressure condenser 1 , is provided. At a bottom portion of the intermediate pressure condenser 2 , an intermediate pressure hot well 26 is provided. The intermediate pressure hot well 26 consists of a liquid phase part 26 a serving as a bottom portion where the condensate is stored, and a vapor phase part 26 b provided above the liquid phase part 26 a . The vapor phase part 26 b is the reheat chamber 22 . The liquid phase part 6 a of the high pressure hot well 6 and the liquid phase part 26 a of the intermediate pressure hot well 26 communicate with each other by a condensate tube 11 .
[0016] The low pressure condenser 3 has a lower inner pressure than the intermediate pressure condenser 2 , and has a low pressure turbine 83 mounted on a head side. A low pressure cooling tube bank 38 constituted by a number of heat-transfer pipes is provided inside the condenser, similarly to the high pressure condenser 1 and the intermediate pressure condenser 2 . A reheat chamber 23 partitioned by a pressure shroud 5 is provided at a lower portion of the low pressure cooling tube bank 38 .
[0017] In the reheat chamber 23 , a steam duct 30 serving as high pressure steam introducing means is provided and connected to the reheat chamber 22 of the intermediate pressure condenser 2 . At a bottom portion of the low pressure condenser 3 , a low pressure hot well 36 is provided. The low pressure hot well 36 consists of a liquid phase part 36 a serving as a bottom portion where the condensate is stored, and a vapor phase part 36 b provided above the liquid phase part 36 a . The vapor phase part 36 b is the reheat chamber 23 . The liquid phase part 26 a of the intermediate pressure hot well 26 and the liquid phase part 36 a of the low pressure hot well 36 communicate with each other by a condensate tube 31 . Furthermore, the heater drain tube 13 is connected to the low pressure condenser 3 , and a low pressure baffle 39 is provided at the connection part.
[0018] As cooling water, for example, sea water is introduced into each of the high pressure cooling tube bank 8 , the intermediate pressure cooling tube bank 28 and the low pressure cooling tube bank 38 . In the multistage pressure condenser, the high pressure cooling tube bank 8 , the intermediate pressure cooling tube bank 28 and the low pressure cooling tube bank 38 are connected serially. The cooling water is first introduced into the low pressure cooling tube bank 38 , passes through the intermediate pressure cooling tube bank 28 after passing through the low pressure cooling tube bank 38 , and is finally introduced intro high pressure cooling tube bank 8 and discharged.
[0019] In the high pressure cooling tube bank 8 , the high pressure turbine exhaust which finishes the work at the high pressure turbine 81 and is supplied to the high pressure condenser 1 is condensed as a high pressure condensate by exchanging heat via the heat-transfer pipes with the cooling water of the highest temperature introduced into the high pressure cooling tube bank 8 , and is recovered in the liquid phase part 6 a of the high pressure hot well 6 of the high pressure condenser 1 .
[0020] In the intermediate pressure cooling tube bank 28 , the intermediate pressure turbine exhaust which finishes the work at the intermediate pressure turbine 82 and is supplied to the intermediate pressure condenser 2 is condensed as an intermediate pressure condensate by exchanging heat via the heat-transfer pipes with the cooling water passing through the intermediate pressure cooling tube bank 28 . The intermediate pressure condensate is temporarily stored on the pressure shroud 4 of the intermediate pressure condenser 2 and then sprayed into the reheat chamber 22 through a number of circle holes formed on a perforated panel provided on the pressure shroud 4 . The high pressure steam is introduced into the reheat chamber 22 from the vapor phase part 6 b of the high pressure hot well 6 provided in the high pressure condenser 1 via the steam duct 10 . The intermediate pressure condensate sprayed into the reheat chamber 22 by the high pressure steam is directly reheated by the heat exchange. The reheated intermediate condensate is finally stored in the liquid phase part 26 a of the intermediate pressure hot well 26 , supplied to the liquid phase part 6 a of the high pressure hot well 6 via the condensate tube 11 , and supplied to a feed water heater (not shown) through a condensate outlet box 7 .
[0021] In the low pressure cooling tube bank 38 , the low pressure turbine exhaust which finishes the work at the low pressure turbine 83 and is supplied to the low pressure condenser 3 is condensed as a low pressure condensate by exchanging heat via the heat-transfer pipes with the cooling water of the lowest temperature passing through the low pressure cooling tube bank 38 . The low pressure condensate is temporarily stored on the pressure shroud 5 of the low pressure condenser 3 and then sprayed into the reheat chamber 23 through a number of circle holes formed on a perforated panel provided on the pressure shroud 5 . The high pressure steam in the vapor phase part 6 b of the high pressure hot well 6 is further introduced into the reheat chamber 23 from the reheat chamber 22 serving as the vapor phase part 26 b of the intermediate pressure hot well 26 via the steam duct 30 . The low pressure condensate sprayed into the reheat chamber 23 by the high pressure steam is directly reheated by the heat exchange. The reheated low condensate is finally stored in the liquid phase part 36 a of the low pressure hot well 36 , supplied to the liquid phase part 6 a of the high pressure hot well 6 via the condensate tube 31 , the liquid phase part 26 a of the intermediate pressure hot well 26 and the condensate tube 11 , and supplied to a feed water heater (not shown) through the condensate outlet box 7 .
[0022] A heater drain generated by condensing in the feed water heater bleed steam of the steam turbine for reheating the feed water flows into the heater drain tube 13 . The flowing heater drain, which is recovered in the high pressure condenser 1 or the low pressure condenser 3 , collides with the high pressure baffle 9 or the low pressure baffle 39 , reduces the flow force and falls into the liquid phase part 6 a of the high pressure hot well 6 or the liquid phase part 36 a of the low pressure hot well 36 .
[0023] As for a known condenser, for example, Jpn. Pat. Appln. KOKAI Publication No. 11-173768, Jpn. U.M. Appln. KOKOKU Publication No. 49-12482, Japanese Patent No. 3706571, Jpn. Pat. Appln. KOKAI Publication No. 49-032002 and the like should be referred to.
BRIEF SUMMARY OF THE INVENTION
(Problem to be Solved by the Invention)
[0024] The temperature of the heater drain recovered in the condenser is higher than the saturation temperature in the condenser, and oxygen is often dissolved in the heater drain at a high concentration. In some cases, 40% or more of the entire fluid flowing in the condenser is the heater drain. For this reason, the temperature of the heater drain and oxygen dissolved in the heater drain give great influences to the performance and operation of the heater and plant.
[0025] When the heater drain collides with the baffle and falls similarly to the prior art, oxygen dissolved in the heater drain does not completely discharge but falls into the hot well, which results in increasing the concentration of oxygen dissolved in the condensate or greatly waving the liquid surface in accordance with the fall into the hot well.
[0026] If a large quantity of oxygen is dissolved in the condensate, the constituent elements of the power plant are corroded due to the chemical reaction and the like. The oxygen dissolved in the condensate therefore needs to be maintained at a low concentration at any time during the operation of the plant.
[0027] The present invention has been accomplished under those circumstances. The object of the present invention is to obtain a condenser capable of reducing oxygen dissolved in the heater drain recovered in the condenser.
(Means for Solving the Problem)
[0028] A condenser according to one aspect of the present invention comprises: a high pressure side condenser; a high pressure side cooling tube bank provided inside the high pressure side condenser, which has a high pressure side cooling water introduced therein and condenses a high pressure side turbine exhaust by heat exchange with the high pressure side cooling water to obtain a high pressure side condensate; a high pressure side hot well provided at a bottom portion of the high pressure side condenser; a low pressure side condenser which has an inner pressure lower than the high pressure side condenser; a low pressure side cooling tube bank provided inside the low pressure side condenser, which has a low pressure side cooling water introduced therein and condenses a low pressure side turbine exhaust by heat exchange with the low pressure side cooling water to obtain a low pressure side condensate; a pressure shroud provided at a lower part than the low pressure side cooling tube bank, inside the low pressure side condenser; a low pressure side hot well provided at a lower part of the pressure shroud, of the low pressure side condenser; high pressure steam introducing means provided at the low pressure side hot well, for communicating with an inner side of the high pressure side condenser and introducing high pressure steam; low pressure side condensate introducing means provided at the pressure shroud, for introducing a low pressure side condensate into the low pressure side hot well; a flash box which communicates with at least one of the high pressure side hot well and the low pressure side hot well, flashes a heater drain from a feed water heater, and urges at least one of the high pressure side hot well and the low pressure side hot well to recover the flashed heater drain; and a flash steam path which introduces flash steam generated inside the flash box into at least one of an interval between the high pressure side cooling tube bank and the high pressure side hot well and an interval between the low pressure side cooling tube bank and the low pressure side hot well.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0029] FIG. 1A is a front sectional view showing a structure of a multistage condenser according to the first embodiment of the present invention.
[0030] FIG. 1B is a side sectional view showing the structure of the multistage condenser according to the first embodiment of the present invention.
[0031] FIG. 2A is a front sectional view showing a structure of a multistage condenser according to the second embodiment of the present invention.
[0032] FIG. 2B is a side sectional view showing the structure of the multistage condenser according to the second embodiment of the present invention.
[0033] FIG. 3A is a front sectional view showing a structure of a multistage condenser according to the third embodiment of the present invention.
[0034] FIG. 3B is a side sectional view showing the structure of the multistage condenser according to the third embodiment of the present invention.
[0035] FIG. 4A is a front sectional view showing a structure of a multistage condenser according to the prior art.
[0036] FIG. 4B is a side sectional view showing the structure of the multistage condenser according to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Embodiments of the present invention are explained below with reference to the accompanying drawings.
1st Embodiment
[0038] FIG. 1A is a front sectional view showing a structure of a multistage condenser 101 according to the first embodiment of the present invention. FIG. 1B is a side sectional view showing the structure of the multistage condenser 101 according to the first embodiment.
[0039] In FIG. 1A and FIG. 1B , the same constituent elements as those of the prior art shown in FIG. 4A and FIG. 4B are denoted by the same reference numbers as those in FIG. 4A and FIG. 4B and their detailed explanations are omitted.
[0040] In the conventional multistage condenser shown in FIG. 4A and FIG. 4B , the high pressure baffle 9 is provided at the connection part between the heater drain tube 13 and the high pressure condenser 1 , and the low pressure baffle 39 is provided at the connection part between the heater drain tube 13 and the low pressure condenser 3 . In the multistage condenser 101 according to the present embodiment, however, the high pressure baffle 9 or the low pressure baffle 39 is not provided, but a high pressure flash box 14 is provided on an outside surface of the high pressure condenser 1 and a low pressure flash box 24 is provided on an outside surface of the low pressure condenser 3 .
[0041] A heater drain path 15 formed in a reverse concave shape is provided in the high pressure flash box 14 provided on the outside surface of the high pressure condenser 1 . One of lower parts of the heater drain path 15 formed in the reverse concave shape is partitioned into a drain channel part 15 a and a flash steam path 17 adjacent thereto by a partition plate 15 d . At a lower part of the drain channel part 15 a partitioned by the partition plate 15 d , a connection port 13 a urging the heater drain from the heater drain tube 13 to be introduced into the flash box 14 is provided. An upper part of the flash steam path 17 communicates with the drain channel part 15 a . At a lower part of the flash steam path 17 , an equalizing port 18 communicating with the vapor phase part 6 b of the hot well 6 of the high pressure condenser 1 is provided. The partition plate 15 d partitioning the drain channel part 15 a and the flash steam path 17 is set to be high such that the heater drain supplied in the drain channel part 15 a does not flow into the flash steam path 17 over the partition plate 15 d.
[0042] A lower end portion of the other lower part of the heater drain path 15 formed in a reverse concave shape is a drain fall part 15 c which communicates with the liquid phase part 6 a of the high pressure hot well 6 . The drain fall part 15 c is adjacent to the drain channel part 15 a and a partition plate 15 e is provided therebetween. The partition plate 15 e is set to be lower than the partition plate 15 d such that the heater drain introduced from the connection port 13 a into the drain channel part 15 a flows from the drain channel part 15 a into the drain fall part 15 c . Furthermore, porous plates 20 are provided at a plurality of steps inside the drain fall part 15 c . In addition, a horizontal portion is provided on the drain channel part 15 a on the side of the partition plate 15 e , and this portion forms a free liquid level part 15 b.
[0043] In other words, in the present embodiment, the heater drain path 15 formed in the flash box 14 is constituted by three parts, i.e., the drain channel part 15 a , the drain fall part 15 c and the flash steam path 17 .
[0044] The heater drain introduced into the high pressure flash box 14 flows into the drain channel part 15 a and is boiled at, particularly, the free liquid level part 15 b to release flash steam. After that, heater drain 16 flows down in the drain fall part 15 c over the partition plate 15 e , becomes a liquid column at the porous plates 20 arranged at a plurality of steps in the drain fall part 15 c , and increases an area of contact with the steam. At this time, the heater drain 16 falls while releasing the non-flashed steam, releases uncondensed gas such as oxygen dissolved in the heater drain 16 , and deaerated. The deaerated heater drain 16 joins the condensate stored in the liquid phase part 6 a of the high pressure hot well 6 from a bottom portion of the drain fall part 15 c . The flash steam and uncondensed gas generated from the heater drain 16 are introduced into the flash steam path 17 over the partition plate 15 d from an upper part of the drain channel part 15 a to flow into the vapor phase part 6 b of the hot well 6 (between the high pressure cooling tube bank 8 and the high pressure hot well 6 ) from the equalizing port 18 provided at the lower end of the flash steam path 17 .
[0045] In the present embodiment, the low pressure flash box 24 is further provided on the side surface of the low pressure condenser 3 . The heater drain path 15 is constituted by the drain channel part 15 a , the drain fall part 15 c and the flash steam path 17 , similarly to the high pressure flash box 14 , and the low pressure flash box 24 acts similarly. The steam and the uncondensed gas flowing through the flash steam path 17 of the low pressure flash box 24 are introduced into the vapor phase part 36 b of the hot well 36 of the low pressure condenser 3 (between the low pressure cooling tube bank 38 and the low pressure hot well 36 ), i.e., into the reheat chamber 23 from the equalizing port 18 . In the multistage condenser, as described above, the high pressure hot well 6 , the intermediate pressure hot well 26 and the low pressure hot well 36 act similarly since they communicate with each other at the vapor phase part by the steam tubes 10 and 15 and at the liquid phase part by the condensate tubes 11 and 16 .
[0046] Thus, according to the present embodiment, the heater drain 16 can be recovered in the multistage condenser 101 after the uncondensed gas such as dissolved oxygen is reduced sufficiently.
[0047] In addition, since the flash steam generated in the high pressure flash box 14 and the low pressure flash box 24 according to the present embodiment is introduced into the multistage condenser 101 via the flash steam path 17 , the flash steam can be used to reheat the condensate flowing down from the pressure shroud 4 and the pressure shroud 5 and the heat efficiency can be thereby enhanced.
[0048] Furthermore, the high pressure flash box 14 and the low pressure flash box 24 according to the present embodiment maintain wide space for boiling the heater drain 16 by forming the free liquid level part 15 b having a wide surface area at the drain path part 15 a in the heater drain path 15 , and can efficiently perform flashing and promote deaeration. In addition, by forming the free liquid level part 15 b , the liquid level inside the drain tank connected to the heater drain system can also be controlled to be at a predetermined height.
2 nd Embodiment
[0049] FIG. 2A is a front sectional view showing a structure of a multistage condenser 102 according to the second embodiment of the present invention. FIG. 2B is a side sectional view showing the structure of the multistage condenser 102 according to the second embodiment.
[0050] The same constituent elements as those of the first embodiment shown in FIG. 1A and FIG. 1B are denoted by the same reference numbers as those in FIG. 1A and FIG. 1B and their detailed explanations are omitted.
[0051] The flash steam path 17 is provided adjacent to the drain channel part 15 a of the heater drain path 15 via the partition plate 15 d in FIG. 1A and FIG. 1B . In a high pressure flash box 34 and a low pressure flash box 44 of the multistage condenser 102 according to the present embodiment, a flash steam path 47 is arranged adjacent to the drain fall part 15 c , at a lower part of the free liquid level part 15 b of the drain channel part 15 a . Steam outlets 19 for supplying flash steam into the flash steam path 47 are provided on a wall surface of the drain fall part 15 c which faces the flash steam path 47 .
[0052] In this structure, the flash steam generated from the drain fall part 15 c passes through the steam outlets 19 and is supplied to the flash steam path 47 after contacting the heater drain 16 falling down from the porous plates 20 .
[0053] Since the falling heater drain 16 and the steam can thereby contact easily, deaeration of the uncondensed gas such as dissolved oxygen in the heater drain 16 can be promoted, the heater drain 16 can be recovered in the multistage condenser 102 after performing the deaeration sufficiently, and the same advantage as that of the first embodiment can be obtained.
[0054] In addition, the heater drain path 15 formed in each of the high pressure flash box 34 and the low pressure flash box 44 according to the present embodiment, is in an approximately rectangular shape, and can be downsized as compared with the high pressure flash box 14 and the low pressure flash box 24 according to the first embodiment.
3 rd Embodiment
[0055] FIG. 3A is a front sectional view showing a structure of a multistage condenser 103 according to the third embodiment of the present invention. FIG. 3B is a side sectional view showing the structure of the multistage condenser 103 according to the third embodiment.
[0056] The same constituent elements as those of the first embodiment shown in FIG. 1A and FIG. 1B are denoted by the same reference numbers as those in FIG. 1A and FIG. 1B and their detailed explanations are omitted.
[0057] The heater drain path 15 is formed in the reverse concave shape in FIG. 1A and FIG. 1B . In a high pressure flash box 54 and a low pressure flash box 64 of the multistage condenser 103 according to the present embodiment, a heater drain path 55 is formed in a shape of approximately rectangular parallelepiped, and the heater drain path 55 shaped in an approximately rectangular parallelepiped is partitioned into a drain fall part 55 c and the flash steam path 17 by a partition plate 55 d . The heater drain path 55 according to the present embodiment does not have a drain channel part or a free liquid level part, but is constituted by the only drain fall part 55 c and flash steam path 17 . The connection port 13 a for introducing the heater drain into the flash box 54 is provided at an upper end of the drain fall part 55 c and, and a lower end of the drain fall part 55 c communicates with the liquid phase part 6 a of the high pressure hot well 6 . The porous plates 20 are provided at a plurality of steps in the drain fall part 55 c , similarly to the first and second embodiments.
[0058] The heater drain 16 becomes a liquid column at the porous plates 20 arranged at a plurality of steps in the drain fall part 55 c , increases an area of contact with the steam, falls down while releasing the flash steam, releases uncondensed gas such as oxygen dissolved in the heater drain 16 , and is thereby deaerated.
[0059] Thus, in the present embodiment, too, the heater drain 16 can be recovered in the multistage condenser 103 after sufficiently reducing the uncondensed gas such as dissolved oxygen and the like, similarly to the first and second embodiments.
[0060] In addition, since the flash steam generated in the high pressure flash box 54 and the low pressure flash box 64 is introduced into the multistage condenser 103 via the flash steam path 17 , the flash steam can be used to reheat the condensate flowing down from the pressure shroud 4 and the pressure shroud 5 and the heat efficiency can be thereby enhanced.
[0061] Moreover, in the present invention, since the heat drain path 55 is constituted by the only drain fall part 55 c and the flash steam path 17 , the high pressure flash box 54 and the low pressure flash box 64 can be further downsized.
[0062] In the present embodiment, too, the steam outlets 19 may be provided on the drain fall part 55 c to urge the falling heater drain 16 to contact a more quantity of the flash steam, similarly to the second embodiment shown in FIG. 2A and FIG. 2B .
[0063] In the first to third embodiments, the multistage condenser having the high pressure condenser, the intermediate pressure condenser, and the low pressure condenser combined is described. However, the present invention can be applied to all of multistage condensers having a plurality of condensers of different pressures combined, such as a multistage condenser having a high pressure condenser and a low pressure condenser combined, and the like.
[0064] In those embodiments, the flash box is provided on each of the high pressure condenser and the low pressure condenser. However, the flash box may be provided on all or one of condensers, for example, of some of condensers such as a high pressure condenser, an intermediate pressure condenser and a low pressure condenser. In addition, one of the flash boxes according to the first to third embodiments can be arranged on the high pressure condenser and one of the others can be arranged on the low pressure condenser. The flash boxes can be applied in combination.
[0065] Furthermore, in those embodiments, the flash boxes are provided on the outside surfaces of the condensers, but may be provided on any parts of the entry side of the heater drain into the condensers, such as the inner side surfaces of the condensers, or separately from the condensers.
[0066] In addition, the multistage condenser is exemplified in the above-described embodiments, but the present invention is not limited to this, but can also be applied to a single-pressure condenser (condenser constituted by one shell). In a case where any one of the flash boxes described in the first to third embodiments is provided on a condenser of a single turbine, the heater drain introduced into the condenser can be separated into the vapor phase and the liquid phase and dissolved oxygen in the heater drain can be reduced.
[0067] The present invention can provide a condenser capable of separating a heater drain introduced therein into a vapor phase and a liquid phase and reducing oxygen dissolved in the heater drain. | A condenser comprises a high pressure side condenser, a high pressure side cooling tube bank, a high pressure side hot well, a low pressure side condenser, a low pressure side cooling tube bank, a pressure shroud provided inside the low pressure side condenser, a low pressure side hot well, high pressure steam introducing portion, low pressure side condensate introducing portion, a flash box which communicates with at least one of the high pressure side hot well and the low pressure side hot well, flashes a heater drain from a feed water heater, and urges at least one of the high pressure side hot well and the low pressure side hot well to recover the flashed heater drain, and a flash steam path which introduces flash steam generated inside the flash box into at least one of the high pressure side hot well and the low pressure side hot well. | 5 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The field of this invention is partition wall systems where a temporary wall is positioned to partition a room into separated parts. Such systems are applicable and highly useful in residential apartments and homes, lofts, offices, theaters, schools, hospitals, gymnasiums and other institutional, commercial and industrial buildings.
[0003] 2. Prior Art
[0004] Need for temporary partitioning of space occurs in countless situations, as when separate spaces are needed within a given room or when a particular room is too large for the desired use, and specifically in residential apartments and homes where the total space is limited and within that space an additional bedroom, storage, den or other work space is temporarily needed.
[0005] As indicated above, the field of this invention is temporary partition wall systems where it is contemplated that a temporary wall will, at a future date, be removed or moved. Common and typical problems associated with temporary removable walls, or partition walls generally, in the prior art include:
[0006] 1. Residual damage to the ceiling, floor and/or walls after removal of the temporary wall, requiring plastering, painting and/or other surface repairs and finishing.
[0007] 2. The expensive cost of assembly and erection of temporary walls because of the requirement for a professional installer.
[0008] 3. The expensive cost of the temporary wall components.
[0009] 4. The cost of transporting and/or storing the relatively heavy wall components.
[0010] 5. The difficulty or impossibility for residential tenants to do their own assembly because it is too heavy and/or complicated.
[0011] 6. The difficulty and high cost to apply finish molding at the ceiling, floor and walls to achieve a finished appearance.
[0012] 7. The difficulty to achieve strength, stability and sound-proofing.
[0013] 8. The fact that typical prior art temporary walls either do not include internal wiring or pre-formed door frames or windows.
[0014] 9. Height limitations of prior art temporary walls.
[0015] In summary, there is a very great need for temporary walls in residential institutional, entertainment, and commercial buildings, and there are many undesirable costs, difficulties and downsides associated with such walls. Interested persons must either accept the collection of advantages and disadvantages or else do without the temporary walls. The new temporary movable/removable compression partition system overcomes or reduces most of the above-described problems in prior art partition systems.
SUMMARY OF THE NEW INVENTION
[0016] The new compression partition wall system includes all or various combinations of the following features and advantages:
[0017] 1. The walls of this partition system comprise lightweight material, so that a professional or non-professional average homeowner can handle, move and install the walls. A typical new wall panel will weigh about 50 pounds compared to a typical prior art panel which weight 130 pounds.
[0018] 2. This partition wall employs a compression system so that fasteners to the ceiling, floor and wall are not needed. Therefore, damage is not caused to these surfaces and repair to said surfaces is not required when the partition is removed.
[0019] 3. This compression wall system, also called “Pressure Lock System”, includes tracks at the ceiling and on the floor respectively above and below the temporary wall. Pressure feet extending upward and downward respectively from the top and bottom of the temporary wall, press against the two tracks to level and tightly and securely stabilize the wall with respect to the ceiling and floor. Each pressure foot is axially adjustable to adjust the wall elevation position and to achieve horizontal stability, thus maintaining the wall in its vertical orientation and in its lateral (north, south, east and west) location. The tracks are preferably channel-shaped, but may alternatively be generally flat, thin planks.
[0020] 4. The new temporary compression wall is constructed of a plurality of panels which are normally eight feet high for typical eight feet high ceilings by four feet wide, but these dimensions may vary. To form a wall, vertically oriented panels are placed edge-to-edge and removably joined together. In a preferred embodiment an I-beam serves as the junction element, with adjacent side edges of adjacent panels positioned in one of the opposite channel-shaped sides of the I-beam. Along the top and bottom of each panel is secured a horizontal channel having integrated threads (threaded holes) to receive threaded shanks of the pressure feet. Thus, the vertical pressure is applied along the horizontal length of each panel to both the ceiling and the floor surfaces without causing any damage to these surfaces.
[0021] 5. This new temporary wall system can also be used in lofts or locations where the ceilings are exceptionally high, by attaching piggyback panels to the standard height partitions.
[0022] It is thus an object of this invention to provide an improved temporary movable/removable partition wall system which does not damage the ceiling or floor when installed.
[0023] It is a further object of this invention to provide a temporary partition wall system which is removably secured in a selected location by using axially adjustable pressure feet that extend toward the ceiling and the floor. In a preferred embodiment a ceiling track is positioned between the ceiling and upper pressure feet, and a floor track is positioned between the floor and the lower pressure feet.
[0024] An additional object is to provide a temporary compression partition wall formed of light weight panels that can be easily and quickly connected by their side edges to have a wall of desired length. In a preferred embodiment each two adjacent panel edges fit into opposite sides of a vertical I-beam with removable biscuits extending through slots in the web of the I-beam and into slots in the side edges of the panels. It is an additional object to provide a temporary wall system that can be handled, installed, removed and stored by both non-professionals and by professionals.
[0025] These and other objects of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a fragmentary elevation view of the temporary partition of this invention shown installed to the ceiling, floor and walls of a room.
[0027] FIG. 2 is a top plan view in partial section taken along line 2 - 2 in FIG. 1 , showing one end of the new partitioned wall adjacent a permanent wall.
[0028] FIG. 3 is a fragmentary elevation view in section taken along line 3 - 3 in FIG. 1 , showing a top portion of the new partitioned wall adjacent to the ceiling.
[0029] FIG. 4 is a fragmentary elevation view in section taken along line 4 - 4 in FIG. 1 , showing a bottom portion of the new partitioned wall adjacent to the floor.
[0030] FIG. 5 is a fragmentary elevation view in section taken along line 5 - 5 in FIG. 1 , showing a top portion of the header panel above the door frame adjacent to the ceiling.
[0031] FIG. 6 is a fragmentary top plan view in section taken along line 6 - 6 in FIG. 1 , showing the attached side edges of two adjacent panels.
[0032] FIG. 7 is a fragmentary top plan view partially in section taken along line 7 - 7 in FIG. 3 , showing a wrench applied to one of the pressure feet.
[0033] FIG. 8 is a fragmentary elevation view in section taken along line 8 - 8 in FIG. 6 , showing the connection of adjacent side edges of two adjacent panels.
[0034] FIG. 9 is a fragmentary perspective exploded view of a new temporary compression partition wall of this invention, including attached partitions and pressure feet at the top and bottom thereof and ceiling and floor tracks.
[0035] FIG. 10 is a fragmentary exploded perspective view enlarged of an upper portion of the assembly of FIG. 9 .
[0036] FIG. 11 is a fragmentary elevation view of a new temporary wall similar to FIG. 1 , but showing interlocking piggyback panels attached to the tops of regular panels for a partition wall having a height greater than the standard eight feet.
[0037] FIG. 12 is a fragmentary top plan view in section taken along line 12 - 12 in FIG. 11 , of an end post portion of the partitioned wall.
[0038] FIG. 13 is a fragmentary elevation view in section taken along line 13 - 13 in FIG. 11 , showing at the top of the connection of the upper part of the wall to the ceiling and at the bottom showing the connection of the piggyback panel to the basic panel.
[0039] FIG. 14 is a fragmentary elevation view in perspective showing a temporary partition wall having a principal part at the right angle to an auxiliary part, thus defining a corner.
[0040] FIG. 15 is a fragmentary top plan view in section taken along line 15 - 15 in FIG. 14 , showing the connection of the right angle panels at the corner intersection.
[0041] FIG. 15A is a perspective view of the corner junction column for attaching panels at a right angle as seen in FIGS. 14 and 15 .
[0042] FIG. 16 is a fragmentary elevation view in section taken along line 16 - 16 in FIG. 15 , showing the junction of one right angle panel to the connection column.
[0043] FIG. 17 is a fragmentary top plan view in section showing the junction of two adjacent panels along their adjacent side edges.
[0044] FIG. 18 is a fragmentary elevation view in section taken along line 18 - 18 in FIG. 17 , showing an alternate version of the coupling biscuit for joining two adjacent panels along their mutual edges.
[0045] The features of the invention will become apparent from the following description of the exemplary embodiments taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] FIG. 1 shows an installation of a temporary pressurized wall 10 of my movable/removable compression partition system where the new wall partitions a room 12 into separate parts. Wall 10 is formed of two 8′×4′ panels 14 and 15 , plus door frame 16 , header panel 17 above the door frame 16 and filler panel 18 . As indicated in FIG. 1 , panels 14 and 15 are detachably joined together along their adjacent side edges 14 A and 15 A, as will be described later in detail. Panel 15 is similarly removably attached to panel 17 , and panel 17 is removably attached to panel 18 . Room 12 includes side walls 12 A and 12 B, ceiling 12 E and floor 12 D. Wall 10 has top part 10 A which removably engages ceiling 10 C, and bottom part 10 B which removably engages floor 12 D.
[0047] FIG. 2 is a top plan view in section of panel 18 engaging the room's side wall 12 B. Panel 18 , while narrower than basic panel 14 , has certain typical construction features, such as front and rear panel faces 18 A and 18 B, front and rear bottom (vertical moldings) 18 C and 18 D, and batten clips 19 . Panel 18 also has an end cap, 20 which is a vertical channel 20 extending from top to bottom along the exposed side edge that engages the room's wall 12 B.
[0048] The overall construction of a typical wall panel 14 is seen in FIGS. 9 and 10 as follows. Inner frame 22 comprises vertical inner studs 23 and outer studs 24 usually of aluminum or steel with slots 25 to receive biscuits 26 which will be further described later, for connecting one panel side edge to an adjacent panel side edge. The above-mentioned studs 23 and 24 are coupled to top and bottom beams 27 and 28 by rivets, adhesive or other fastening means to form the basic internal frame. Attached to said inner frame 22 is front panel face 29 , rear panel face 30 is not shown in FIG. 9 , but is visible in FIGS. 3 and 4 . A typical panel comprises an aluminum frame with corrugated cardboard outer skins sold under the name “Miracle Board” by PlyVeneer Products Co. My preferred panel comprises Miracle Board clad with a veneer for a prefinished appearance. The panels are also available with a printable surface for field finishing. All panels are prefabricated, including selected exterior surface, so that they are immediately usable when the wall is assembled and installed.
[0049] As seen in FIGS. 9 , 10 and 3 , secured atop frame 22 by screws 31 is channel track 32 which includes threaded holes 33 . In each threaded hole 33 is one pressure foot 34 , which when rotated, moves axially upward or downward as indicated by arrow 35 . Each of the three threaded holes 33 receives a similar pressure foot 34 . At the bottom of frame 22 is bottom channel track 36 which is the same as top channel track 32 , but inverted, and which include pressure feet 37 , similar to those at the top.
[0050] As seen in FIG. 9 , panels 14 and 15 are coupled together via slotted I-beam 36 whose channel-shape left side 36 A receives an edge of panel 14 and whose channel shape right side 36 B receives the edge of panel 15 . That coupling is stabilized by the above-mentioned biscuits 26 . Other biscuits 37 stabilize the junction of top channel track 32 atop panel 14 with the top channel track of the adjacent and coupled panel 15 .
[0051] At the time of installation of the new temporary compression wall, floor track 41 is positioned at a desired location on the floor, and ceiling track is situated atop the first wall panel. The bottom edge of this first panel is situated in the floor track, and the panel is pivoted upward with the ceiling track on-board at the top. Or the ceiling track may be independently positioned at the ceiling, until the wall panel is pivoted up to engage it. Ceiling and floor tracks are made of standard commercial rigid PVC. Pressure feet 37 and 34 respectively at the bottom and top of the panels are rotated, applying axial pressure via tracks 40 and 41 to the floor and ceiling until the wall is leveled, secured and stabilized in the desired position. Each panel is stabilized relative to adjacent panels by its coupling via an I-beam 36 , in addition to its engagement with the ceiling and to the floor.
[0052] FIG. 3 shows in greater detail the engagement of panel 14 with ceiling 12 C, where pressure foot 34 applies upward vertical face, indicated by arrows 42 through ceiling track 40 to ceiling 12 C.
[0053] As seen in FIGS. 3 and 4 , each pressure foot 34 has a threaded shank 34 A with opposite flats 34 B to receive a wrench 43 which is used to rotate the pressure foot and move it axially and apply the upward vertical face against the ceiling. The wrench is used similarly with the bottom pressure feet engaging the floor track.
[0054] After pressure feet adjustment is complete, the upper position of panel 14 where the pressure feet are visible is covered by front crown molding 18 C and rear crown molding 18 D, each being snapped on via horizontal bead projection 45 and mating horizontal groove 46 in crown molding 18 C. As seen in FIG. 4 , a similar and essentially the same operation and construction is employed at the bottom of the wall, with groove 46 of base molding releasably coupled with projection 45 which extends laterally from floor track 41 .
[0055] FIG. 1 shows door frame 16 with header panel 17 immediately above the door frame. FIG. 10 shows channel components 10 A of door frame 16 and inner frame 17 A of header panel 17 . FIG. 5 shows the top part 17 T of header panel 17 with front and rear faces 17 A and 17 B, junction biscuit 26 for coupling header panel 17 to adjacent basic panel 15 (not shown here). Ceiling track 40 extends above header panel 17 , and front and rear crown moldings 18 C and 18 D extend across the top part 17 T of the header panel. Crown and baseboard moldings are typically of rigid PVC.
[0056] Coupling of adjacent side edges of two panels 14 and 15 is shown in FIGS. 1 , 6 , 8 , and 9 . In FIG. 9 slots 25 are visible where they are vertically spaced along each side edge of the panels. For a typical coupling, as seen in FIG. 6 , slotted rigid PVC I-beam 36 receives one side edge of each panel into the channel-shaped edge. Each biscuits 26 extends through a slot in I-beam 36 and into aligned slots 25 in the two adjacent panels. The sectional viewed FIG. 8 shows in enlarged sectional detail:
[0057] a) Web 36 A of slotted I-beam 36 .
[0058] b) Slotted outside stud 24 A of panel 14 .
[0059] c) Slotted outside stud 24 B of panel 15 .
[0060] d) Upper biscuit 26 A.
[0061] e) Lower biscuit 26 B where a plurality of such biscuits are alternated along the top to bottom length of the panel. Each biscuit has a flange, as flange 26 C of biscuit 26 A and flange 26 D of biscuit 26 B. With this arrangement, flange 26 C of biscuit 26 A, for example, is sandwiched between stud 24 B and web 36 A of I-beam 36 , so that biscuit 26 A cannot fall or be pushed out of the position shown, where it has approximately half its length in panel 14 and half in panel 15 . Biscuit 26 B is similarly situated, except that its flange 26 D is on the left side of web 36 A. This prevents the biscuits from falling or being pushed out of position, where their presence helps to stabilize the panels relative to each other. Principal stabilization exists mainly from the pressure feet exerting upward and downward forces respectively against the ceiling and floor.
[0062] FIGS. 11 , 12 and 13 illustrate an extension system where a basic temporary compression wall of this invention can be extended to function in rooms with very high ceilings having the height of twelve feet, for example. The wall of FIG. 11 corresponds generally to the wall of FIG. 1 , except that the basic wall panels 50 in FIG. 11 are modified to receive the extension headers (extension header panels) 52 . As seen in FIG. 13 , the pressure feet 53 are now at the top of extension header 52 and not at the top of basic panel 50 . However, in the top channel track 32 of panel 50 , the threaded hole 54 is used to receive junction bolt 55 to secure extension panel 52 to basic panel 50 . There is a plurality of bolts 55 laterally spaced along the top of panel 50 from side-to-side.
[0063] Between panels 50 and 52 is a horizontal I-beam 56 which defines opposite upper and lower channel-shape tracks to receive adjacent edges of said panels. After such junction of panels, battens 57 are clipped on to cover and hide the junction.
[0064] The top part of header panel 52 has the previously described pressure feet, later covered by front and rear crown moldings 18 C and 18 D. FIG. 12 shows the engagement of the side-to-side edge of panel 50 with door frame 16 .
[0065] FIGS. 14 , 15 , 15 A and 16 show the construction of the new wall to form a corner 60 with a right angle panel arrangement. The new corner 60 includes a corner column 61 , seen in FIGS. 15 and 15A , as a unitary molded element defining vertical channels 62 to receive side edges of panels 63 in the usual manner as described earlier. There are additional vertical ribs 64 molded contiguously with column 61 and serving as batten clips to engage and removably hold vertical inner cosmetic molding 65 and outer cosmetic molding 66 . FIG. 16 , as a section taken in FIG. 15 , shows biscuit 67 between panel 63 and column 61 .
[0066] FIGS. 17 and 18 correspond generally to FIGS. 1 , 6 , and 9 illustrating a second embodiment of biscuit 70 which has tapered resilient flanges 71 A and 71 B on each side. In these figures, there is slotted I-beam 72 , slotted outer stud 73 of panel 74 , and slotted outer stud 75 of panel 76 . During assembly, biscuit 70 is pushed in the leftward direction through the slot in stud 73 , through slot 78 in I-beam 72 and through slot 79 in stud 75 . Flange 71 A is resiliently deflected in order for biscuit 70 to pass through slots 78 and 79 . Then flange 71 A bars further lateral movement of biscuit 70 to the left and flange 71 B bars lateral movement of biscuit 70 to the right.
[0067] The components and materials used in this new temporary wall partition system may vary from the many commercially available products. Preferred materials include PVC for the battens (moldings), PVC for the ceiling and floor tracks, PVC for the crown and base moldings, PVC for the discs of pressure feet, PVC for the stabilizing 1⅝″ thick biscuits 26 between prefabricated panels 14 , 15 for vertical stability and 1⅝″ thick aluminum for biscuits 37 between adjacent ends of channel tracks at the ceiling and floor.
[0068] While the invention has been described in conjunction with several embodiments, it is to be understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims. | A temporary movable/removable compression partition wall system for partitioning a room includes a wall component and spaced-apart pressure feet at the top of the wall for pressing against a track positioned between the top of the wall and the ceiling and additional spaced-apart pressure feet at the bottom of the wall for pressing against a track positioned between the bottom of the wall and the floor. This wall is temporarily, securely and rigidly positionable at a selected location in a room and subsequently removable with substantially no damage to the ceiling, floor or walls. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage Application of International Application PCT/JP12/065588, filed Jun. 19, 2012, which claims the benefit of priority under 35 U.S.C. §119 from Japanese Patent Application No. 2011-145472, filed Jun. 30, 2011.
TECHNICAL FIELD
The present invention relates to a linear actuator in which a slide table is made to move reciprocally along an axial direction of a cylinder main body.
BACKGROUND ART
Heretofore, a linear actuator, for example, which is made up of a fluid pressure cylinder or the like, has been used as a means for transporting workpieces under the supply of a pressure fluid. As disclosed in Japanese Patent No. 3795968, the present applicants have proposed a linear actuator, which is capable of transporting a workpiece that is loaded onto a slide table by causing the slide table to move reciprocally in a straight line along a cylinder main body. However, with the aforementioned linear actuator, in recent years, there has been a demand to reduce manufacturing costs and to simplify the structure of the apparatus.
SUMMARY OF INVENTION
A general object of the present invention is to provide a linear actuator, which makes it possible to reduce production costs and to simplify the structure of the linear actuator.
The present invention is characterized by a linear actuator in which a slide table is made to move reciprocally along an axial direction of a cylinder main body, comprising:
a guide mechanism including a guide block attached to the cylinder main body and in which circulation grooves are formed through which a plurality of rolling bodies roll and circulate, and a cover member disposed on an end of the guide block, the guide mechanism guiding the slide table along an axial direction of the cylinder main body, and
a retainer installed on the guide block, for retaining the rolling bodies freely circulatable in the circulation grooves, and for retaining the cover member with respect to the guide block,
wherein the circulation grooves are formed to open in the guide block along a longitudinal direction thereof, and the retainer is disposed detachably with respect to the guide block.
According to the present invention, the guide mechanism that constitutes the linear actuator is equipped with the circulation grooves, which open along the longitudinal direction of the guide block, and the plural rolling bodies, which are circulated through the circulation grooves, are retained by the retainer. The retainer retains the plural rolling bodies so as to be freely circulatable in the circulation grooves of the guide block, and the rolling bodies are further retained by the cover member, which is disposed on the end of the guide block.
Accordingly, in comparison with a situation in which a cover member is attached with respect to the guide block by bolts or the like, the cover member can be simplified in structure, together with being more easily assembled through use of the retainer.
Further, on the guide block, instead of providing penetrating through holes in which the rolling bodies are circulated, since circulating grooves are formed that open along the axial direction, compared to a case of forming such through holes, the number of process steps and processing costs can be reduced. As a result, production costs for the linear actuator are reduced, and hence the linear actuator can be manufactured inexpensively.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exterior perspective view of a linear actuator according to a first embodiment of the present invention;
FIG. 2 is an exploded perspective view of the linear actuator shown in FIG. 1 ;
FIG. 3 is an exploded perspective view of the linear actuator of FIG. 2 as seen from a different direction;
FIG. 4 is an overall vertical cross sectional view of the linear actuator of FIG. 1 ;
FIG. 5 is a cross sectional view taken along line V-V of FIG. 4 ;
FIG. 6 is a cross sectional view taken along line VI-VI of FIG. 4 ;
FIG. 7 is a cross sectional view taken along line VII-VII of FIG. 4 ;
FIG. 8 is an exterior perspective view of a guide mechanism that constitutes part of the linear actuator of FIG. 1 ;
FIG. 9 is an exterior perspective view of the guide mechanism of FIG. 8 as seen from a different direction;
FIG. 10 is an exploded perspective view of the guide mechanism shown in FIG. 8 ;
FIG. 11 is an exterior perspective view of a linear actuator according to a second embodiment of the present invention;
FIG. 12 is a cross sectional view taken along line XII-XII of FIG. 11 ;
FIG. 13 is an exploded perspective view of a linear actuator according to a third embodiment of the present invention;
FIG. 14 is an exterior perspective view of a guide mechanism that constitutes part of the linear actuator of FIG. 13 ;
FIG. 15 is an exterior perspective view of the guide mechanism of FIG. 14 as seen from a different direction;
FIG. 16 is an exploded perspective view of the guide mechanism shown in FIG. 14 ;
FIG. 17 is an exterior perspective view of a ball clip that is used in the guide mechanism of FIG. 14 ;
FIG. 18 is a cross sectional view taken along line XVIII-XVIII of FIG. 14 ;
FIG. 19 is a cross sectional view showing a direction perpendicular to the longitudinal direction of the linear actuator of FIG. 13 ; and
FIG. 20 is an exterior perspective view showing a ball clip according to a modification.
DESCRIPTION OF EMBODIMENTS
As shown in FIGS. 1 through 7 , a linear actuator 10 comprises a cylinder main body 12 , a slide table 14 disposed on an upper portion of the cylinder main body 12 and which undergoes reciprocal motion in a straight line along a longitudinal direction (the directions of arrows A and B), a guide mechanism 16 disposed to intervene between the cylinder main body 12 and the slide table 14 for guiding the slide table 14 in the longitudinal direction (the directions of arrows A and B), and a stopper mechanism 18 , which is capable of adjusting a displacement amount of the slide table 14 .
The cylinder main body 12 has a rectangular cross section and has a predetermined length along the longitudinal direction (the directions of arrows A and B). A recess 20 having a sunken arcuate shape in cross section is formed roughly in the center on the upper surface of the cylinder main body 12 (see FIG. 2 ). The recess 20 extends along the longitudinal direction (the directions of arrows A and B), and in the recess 20 , a pair of penetrating bolt holes 24 is provided, through which connecting bolts 22 are inserted for connecting the cylinder main body 12 with the guide mechanism 16 .
Further, on one side surface of the cylinder main body 12 , first and second ports 26 , 28 for supply and discharge of a pressure fluid are formed perpendicularly to the longitudinal direction of the cylinder main body 12 . The first and second ports 26 , 28 communicate with a pair of penetrating holes 30 a , 30 b to be described later. Furthermore, on the opposite side surfaces of the cylinder main body 12 , sensor attachment grooves 32 a , 32 b are formed, respectively, at positions along the longitudinal direction (the directions of arrows A and B), which have sensors (not shown) mounted therein.
On the bottom surface of the cylinder main body 12 , the pair of bolt holes 24 is formed centrally in the widthwise direction on the axial line. The connecting bolts 22 are inserted through the bolt holes 24 from below. Additionally, the ends of the connecting bolts 22 project from the upper surface of the cylinder main body 12 , and are connected mutually by threaded engagement with a guide block 76 of the guide mechanism 16 .
On the other hand, inside the cylinder main body 12 , a pair of penetrating holes 30 a , 30 b is formed, which penetrates along the longitudinal direction (the directions of arrows A and B), the one penetrating hole 30 a and the other penetrating hole 30 b being disposed substantially in parallel with each other and separated by a predetermined distance. Inside the penetrating holes 30 a , 30 b , cylinder mechanisms 42 are provided, respectively, each including a piston 38 on which a sealing ring 34 and a magnet 36 are installed on the outer circumference thereof, and a piston rod 40 connected to the piston 38 . The cylinder mechanisms 42 are constituted by installation of the pair of pistons 38 and the piston rods 40 , respectively, in the pair of penetrating holes 30 a , 30 b.
As shown in FIG. 5 , the penetrating holes 30 a , 30 b are closed and sealed at one end thereof by caps 44 , whereas other ends of the penetrating holes 30 a , 30 b are sealed hermetically by rod holders 46 , which are retained via locking rings.
Furthermore, one of the penetrating holes 30 a communicates respectively with the first and second ports 26 , 28 , whereas the other penetrating hole 30 b also communicates mutually with the one penetrating hole 30 a via a pair of connecting passages 48 formed between the one penetrating hole 30 a and the other penetrating hole 30 b . More specifically, the pressure fluid is supplied to the first and second ports 26 , 28 and introduced into the one penetrating hole 30 a , and then the pressure fluid is introduced into the other penetrating hole 30 b through the connecting passages 48 . The connecting passages 48 are formed perpendicularly to the direction of extension (the directions of arrows A and B) of the penetrating holes 30 a , 30 b.
The slide table 14 comprises a table main body 50 , and an end plate 52 connected to another end of the table main body 50 . The end plate 52 is connected perpendicularly with respect to the table main body 50 .
The table main body 50 is made up from a base member 54 that extends along the longitudinal direction (the directions of arrows A and B) with a predetermined thickness, and a pair of guide walls 56 a , 56 b that extend downward perpendicularly from both sides of the base member 54 . On inner surfaces of the guide walls 56 a , 56 b , first ball guide grooves 60 are formed for guiding balls (rolling bodies) 58 of the guide mechanism 16 , to be described later. The first ball guide grooves 60 are recessed with substantially semicircular shapes in cross section.
Further, on one end of the table main body 50 , a holder portion 64 of the later-described stopper mechanism 18 is fixed by a pair of bolts 62 a . Further, on another end of the table main body 50 , an end plate is fixed thereto by another pair of bolts 62 b.
Four workpiece retaining holes 66 are formed in the base member 54 , which are separated mutually by predetermined distances. The workpiece retaining holes 66 are used for fixing a workpiece (not shown), for example, which is mounted on the slide table 14 .
The end plate 52 is fixed to the other end of the table main body 50 , and is disposed to face toward an end surface of the cylinder main body 12 . The end plate 52 also is fixed to respective ends of the piston rods 40 , which are inserted through a pair of rod holes 68 formed in the end plate 52 . Owing thereto, the slide table 14 including the end plate 52 is displaceable together with the piston rods 40 along the longitudinal direction (the directions of arrows A and B) of the cylinder main body 12 .
Further, a damper 70 is mounted through a damper installation hole substantially in the center of the end plate 52 . The damper 70 is made from an elastic material such as rubber or the like, and is mounted such that an end portion thereof projects outwardly from the end surface of the end plate 52 , so that upon displacement of the slide table 14 , the damper 70 comes into abutment against an end surface of the cylinder main body 12 .
The stopper mechanism 18 includes the holder portion 64 disposed on a lower surface of one end of the table main body 50 , a stopper bolt 72 screw-engaged with respect to the holder portion 64 , and a lock nut 74 for regulating advancing and retracting movements of the stopper bolt 72 . The stopper mechanism 18 is disposed so as to face toward an end surface of the guide mechanism 16 , which is disposed on the cylinder main body 12 .
The holder portion 64 is formed in a block-like shape and is fixed by two bolts 62 a with respect to the base member 54 of the table main body 50 of the slide table 14 . In a center part of the holder portion 64 , a screw hole is formed in which the stopper bolt 72 is screw-engaged.
The stopper bolt 72 , for example, is made from a shank-shaped stud bolt engraved with threads on the outer peripheral surface thereof, and is screw-engaged in a screw hole of the holder portion 64 . The lock nut 74 is screw-engaged with the stopper bolt 72 at a region projecting from an end surface of the holder portion 64 .
Additionally, by threaded rotation of the stopper bolt 72 with respect to the holder portion 64 , the stopper bolt 72 is displaced along the axial direction (the directions of arrows A and B), so as to approach and separate away from the guide mechanism 16 , and by threaded rotation of the lock nut 74 , advancing and retracting movements of the stopper bolt 72 are regulated.
As shown in FIGS. 8 through 10 , the guide mechanism 16 includes the wide flat guide block 76 , a pair of cover blocks (cover members) 78 a , 78 b disposed on opposite ends of the guide block 76 , plural balls 58 that circulate in the longitudinal direction of the guide block 76 , and a pair of ball clips (retaining members) 82 a , 82 b that retain the balls 58 in respective ball circulation grooves 80 of the guide block 76 . Further, the guide mechanism 16 includes a pair of cover clips (other retaining members) 84 a , 84 b that serve to retain the cover blocks 78 a , 78 b with respect to the guide block 76 , and two pairs of cover plates 86 a , 86 b which are mounted respectively on the cover blocks 78 a , 78 b.
The guide block 76 , is formed, for example, from a metal material such as stainless or carbon steel, and is formed with second ball guide grooves 88 on opposite side surfaces thereof along the longitudinal direction (the directions of arrows A and B), and with the pair of ball circulation grooves 80 , in which the balls 58 are installed, formed on a bottom surface thereof along the longitudinal direction (the directions of arrows A and B). More specifically, the second ball guide grooves 88 and the ball circulation grooves 80 are formed substantially in parallel with each other. Moreover, the second ball guide grooves 88 are formed with semicircular shapes in cross section in the same manner as the first ball guide grooves 60 .
Additionally, when the slide table 14 is arranged on an upper part of the guide mechanism 16 , the second ball guide grooves 88 are formed at positions confronting the first ball guide grooves 60 , and the ball circulation grooves 80 are formed in facing relation to the upper surface of the cylinder main body 12 .
Further, on the upper surface of the guide block 76 , in a central part thereof, an upwardly bulging projection 90 is formed that extends in the longitudinal direction. The projection 90 is formed with a trapezoidal shape in cross section becoming slightly narrower in an upward direction.
The cover blocks 78 a , 78 b , for example, are made from a resin material such as nylon or the like, each of which includes a main body portion 92 , and a cutout portion 94 , which is cutout substantially centrally in the widthwise direction of the main body portion 92 .
The main body portion 92 is formed in a divided manner in left and right widthwise directions about the cutout portion 94 , with one end surface thereof that abuts against the guide block 76 being formed in a planar shape, and the other end surface thereof opposite from the one end surface being formed in a stepped shape.
Further, substantially in the center in the widthwise direction of the main body portion 92 , an arcuate section 96 is formed, which projects downwardly with an arcuate shape in cross section. The arcuate section 96 is inserted into the recess 20 when the guide mechanism 16 is connected to the upper part of the cylinder main body 12 .
Furthermore, when the main body portions 92 are placed in abutment against end surfaces of the guide block 76 , the ends of the ball circulation grooves 80 are closed, and since the cutout portions 94 thereof penetrate from the one end surface to the other end surface of the cover blocks 78 a , 78 b , the end surfaces of the guide block 76 are exposed through the cutout portions 94 . In addition, upon displacement of the slide table 14 , displacement of the slide table 14 is regulated by abutment of the stopper bolt 72 of the stopper mechanism 18 against one end surface of the guide block 76 .
Further, on one end surface of the main body portion 92 , a pair of return guides 98 , which serve to reverse the direction in which the balls 58 are circulated, is disposed respectively via installation holes 100 . The return guides 98 are equipped with groove-shaped guide portions 102 formed with semicircular shapes in cross section, through which the balls 58 roll along an outer circumferential surface thereof. In addition, when the cover blocks 78 a , 78 b , in which the return guides 98 are installed, are mounted on opposite end surfaces of the guide block 76 , one of the ends of the return guides 98 are connected to the ball circulation grooves 80 , whereas other ends thereof are connected to the second ball guide grooves 88 .
More specifically, the ball circulation grooves 80 and the second ball guide grooves 88 are connected by the return guides 98 , such that, in the return guides 98 , the balls 58 roll continuously while the direction of movement thereof is converted 180° from the ball circulation grooves 80 to the first and second ball guide grooves 60 , 88 via the guide portions 102 .
On the other hand, on the other side surface of the main body portion 92 , a pair of retaining holes 104 a , 104 b , which are separated mutually by a predetermined distance, is formed about the cutout portion 94 . Positioning pins 106 a , 106 b that project in the longitudinal direction are formed respectively on outer sides in the widthwise direction with respect to the retaining holes 104 a , 104 b . The retaining holes 104 a , 104 b are formed with a predetermined depth toward the one end surface side of the main body portion 92 .
Further, on the other end surface of the main body portion, regions thereof having the positioning pins 106 a , 106 b are formed to project out in a direction away from the one end surface with respect to the region thereof in which the retaining holes 104 a , 104 b are formed.
More specifically, on the other end surface of the main body portion 92 , outer sides thereof in the widthwise direction are formed with stepped portions, which project at a predetermined height in a direction away from the one end surface, with respect to a central vicinity alongside the cutout portion 94 .
Furthermore, clip grooves 108 , in which portions of the ball clips 82 a , 82 b are inserted, are formed on sides of the retaining holes 104 a , 104 b . The clip grooves 108 are formed with L-shapes in cross section, so as to connect with the lower surface from the other end surface of the main body portion 92 , and end portions of the clip grooves 108 communicate with the ball circulation grooves 80 , whereas on other end portions thereof, clip holes (not shown) are formed, which are recessed toward the one end surface side of the main body portion 92 . The clip grooves 108 are formed with a width dimension that corresponds to the thickness of the ball clips 82 a , 82 b , to be described below.
The ball clips 82 a , 82 b , for example, are formed from a metal material such as stainless steel or the like, each of which comprises a first straight portion 112 formed in a straight line, and a pair of first bent portions 114 a , 114 b formed on opposite ends of the first straight portion 112 . The first bent portions 114 a , 114 b are formed perpendicularly with respect to the first straight portion 112 . One of the first bent portions 114 a and the other of the first bent portions 114 b are bent in the same direction with respect to the first straight portion 112 , and are formed substantially in parallel mutually with one another.
Further, on ends of the first bent portions 114 a , 114 b , engagement parts 116 are formed, respectively, which are folded again perpendicularly from the ends and extend in directions to approach one another mutually. The engagement parts 116 are formed substantially in parallel with the first straight portion 112 , and with a predetermined length with respect to the first bent portions 114 a , 114 b.
Furthermore, on the ball clips 82 a , 82 b , the distance in the longitudinal direction (the directions of arrows A and B) between one of the first bent portions 114 a and the other of the first bent portions 114 b is substantially the same or slightly smaller than the length in the longitudinal direction (the directions of arrows A and B) of the pair of cover blocks 78 a , 78 b and the guide block 76 .
In addition, the first straight portions 112 of the ball clips 82 a , 82 b are installed on the lower surface side of the guide block 76 , and are inserted inside the ball circulation grooves 80 . In greater detail, the first straight portions 112 are arranged in the ball circulation grooves 80 on a central side of the guide block 76 , and at locations proximate to the lower surface of the guide block 76 (see FIG. 7 ).
More specifically, the first straight portions 112 retain the balls 58 by abutment against outer circumferential surfaces of the balls 58 in the ball circulation grooves 80 , and the balls 58 are retained in the ball circulation grooves 80 in a condition that prevents falling out of the balls 58 in a direction away from the ball circulation grooves 80 .
Stated otherwise, the first straight portions 112 serve to guide the plural balls 58 in the ball circulation grooves 80 so as to be freely circulatable along the longitudinal direction (the directions of arrows A and B) of the guide block 76 .
Further, in a condition in which the pair of cover blocks 78 a , 78 b is disposed on both end surfaces of the guide block 76 , opposite ends of the first straight portions 112 and the first bent portions 114 a , 114 b of the ball clips 82 a , 82 b are inserted into the clip grooves 108 of the cover blocks 78 a , 78 b , together with the engagement parts 116 being inserted respectively into the clip holes. Consequently, simultaneously with the ball clips 82 a , 82 b being retained with respect to the guide block 76 and the cover blocks 78 a , 78 b , the guide block 76 is sandwiched between the pair of cover blocks 78 a , 78 b while being biased by the ball clips 82 a , 82 b in a direction to be pulled mutually toward each other, so that the cover blocks 78 a , 78 b are retained in a state of abutment against the guide block 76 .
Stated otherwise, the ball clips 82 a , 82 b are doubly equipped with a function to retain the plural balls 58 with respect to the guide block 76 , and with a function to retain the pair of cover blocks 78 a , 78 b with respect to both ends of the guide block 76 .
The cover clips 84 a , 84 b , for example, are formed from a metal material such as stainless steel or the like, each of which comprises a second straight portion 118 formed in a straight line, and a pair of second bent portions 120 a , 120 b formed on both ends of the second straight portion 118 . The cover clips 84 a , 84 b , for example, are formed by wires having a thickness greater than that of the ball clips 82 a , 82 b.
The second bent portions 120 a , 120 b are formed substantially perpendicular to the second straight portion 118 , and include bulging portions 122 that bulge outwardly in the direction of extension (the directions of arrows A and B) of the second straight portion 118 in the vicinity of the ends thereof. One of the second bent portions 120 a and the other of the second bent portions 120 b are bent in the same direction with respect to the second straight portion 118 , and are formed substantially in parallel mutually with one another.
The bulging portions 122 , for example, are arc-shaped in cross section, bulging outwardly such that the bulging portion 122 on one of the second bent portions 120 a and the bulging portion 122 on the other of the second bent portions 120 b approach one another mutually.
Furthermore, on the cover clips 84 a , 84 b , the distance in the longitudinal direction (the directions of arrows A and B) between one of the second bent portions 120 a and the other of the second bent portions 120 b is substantially the same or slightly smaller than the length in the longitudinal direction of the pair of cover blocks 78 a , 78 b and the guide block 76 .
The cover plates 86 a , 86 b , for example, are formed by press forming a plate-like member made from a metal material. The cover plates 86 a , 86 b are installed, as one pair each, respectively, on the other side surfaces of the main body portions 92 on one and the other of the cover blocks 78 a , 78 b.
The cover plates 86 a , 86 b are formed in stepped shapes corresponding to the other side surfaces of the cover blocks 78 a , 78 b , and comprise insertion parts 124 formed on one portion thereof, which are inserted into the retaining holes 104 a , 104 b , and pin holes 126 formed on another portion thereof, on outer sides in the widthwise direction of the cover plates 86 a , 86 b with respect to the insertion parts 124 .
The insertion parts 124 project outwardly in semispherical shapes on one side surface in the thickness direction of the cover plates 86 a , 86 b , and are recessed inwardly on the other side surface thereof.
In addition, when the cover plates 86 a , 86 b are mounted on the cover blocks 78 a , 78 b , the cover plates 86 a , 86 b are placed in abutment against the other end surfaces of the cover blocks 78 a , 78 b , and the positioning pins 106 a , 106 b are inserted in the pin holes 126 , together with the insertion parts 124 being inserted into the retaining holes 104 a , 104 b . Consequently, the pairs of cover plates 86 a , 86 b are mounted in a properly positioned condition with respect to the other end surfaces of the cover blocks 78 a , 78 b.
Further, in a state in which the pair of cover blocks 78 a , 78 b have been mounted on both end surfaces of the guide block 76 , installation of the cover clips 84 a , 84 b is carried out from the upper side of the guide block 76 . At this time, the second straight portions 118 of the cover clips 84 a , 84 b are placed in abutment against the upper surface of the guide block 76 in contact with the projection 90 . In addition, the bulging portions 122 are inserted respectively into the recesses formed on the other side surfaces of the insertion parts 124 .
Consequently, in a state in which the cover plates 86 a , 86 b are in abutment against the cover blocks 78 a , 78 b , and the cover blocks 78 a , 78 b are in abutment against end surfaces of the guide block 76 , the cover plates 86 a , 86 b , the cover blocks 78 a , 78 b , and the guide block 76 are retained by the pair of cover clips 84 a , 84 b , so as not to be displaceable relatively in the longitudinal direction (the directions of arrows A and B). Stated otherwise, the cover clips 84 a , 84 b , the cover plates 86 a , 86 b , the cover blocks 78 a , 78 b , and the guide block 76 are maintained in a connected condition in the longitudinal direction (the directions of arrows A and B) of the guide block 76 .
At this time, the second straight portions 118 of the cover clips 84 a , 84 b are arranged in an exposed manner on an upper portion of the guide block 76 , whereas the first straight portions 112 of the ball clips 82 a , 82 b are arranged in an exposed manner on a lower portion of the guide block 76 .
The linear actuator 10 according to the first embodiment of the present invention basically is constructed as described above. Next, an explanation shall be given concerning assembly of the guide mechanism 16 of the linear actuator 10 .
At first, from the state shown in FIG. 10 , after the plural balls 58 have been installed in the second ball guide grooves 88 and the ball circulation grooves 80 of the guide block 76 , the cover blocks 78 a , 78 b are placed in abutment against both end surfaces of the guide block 76 . In this case, the balls 58 installed in the second ball guide grooves 88 are retained to prevent their falling out from the guide block 76 by a non-illustrated jig or the like.
Next, the pair of ball clips 82 a , 82 b is brought into proximity with respect to the guide block 76 , and after the first straight portions 112 thereof have been inserted inside the pair of ball circulation grooves 80 , the first bent portions 114 a , 114 b are inserted into the clip grooves 108 , together with the engagement parts 116 thereof being inserted respectively in the clip holes. As a result, the plural balls 58 in the ball circulation grooves 80 are retained by the first straight portions 112 of the ball clips 82 a , 82 b , so that the balls 58 cannot fall out from the open ball circulation grooves 80 .
Further, concerning the pair of cover blocks 78 a , 78 b , due to the engagement parts 116 of the pair of ball clips 82 a , 82 b being engaged with the clip holes, and the first bent portions 114 a , 114 b being inserted into the clip grooves 108 , the cover blocks 78 a , 78 b are pressed respectively toward the sides of the guide block 76 . Owing thereto, the cover blocks 78 a , 78 b are retained against both end surfaces of the guide block 76 by the ball clips 82 a , 82 b . Stated otherwise, the ball clips 82 a , 82 b pull on one of the cover blocks 78 a and the other of the cover blocks 78 b in directions to approach one another mutually.
Lastly, the cover plates 86 a , 86 b are mounted respectively on the pair of cover blocks 78 a , 78 b . In this case, first, the insertion parts 124 of the cover plates 86 a , 86 b are inserted into the retaining holes 104 a , 104 b of the cover blocks 78 a , 78 b , and the positioning pins 106 a , 106 b are inserted into the pin holes 126 , whereby the respective pairs of cover plates 86 a , 86 b are positioned with respect to the cover blocks 78 a , 78 b . In addition, the pair of cover clips 84 a , 84 b is arranged in proximity to the guide block 76 and the cover blocks 78 a , 78 b from a side opposite from the ball clips 82 a , 82 b , the second straight portions 118 are placed in abutment against the vicinity of the projection 90 , and the bulging portions 122 are inserted into the insertion parts 124 of the cover plates 86 a , 86 b.
Consequently, by operation of both end parts of the pair of cover clips 84 a , 84 b, a state is maintained in which the cover plates 86 a , 86 b are mounted respectively on the cover blocks 78 a , 78 b , and both end parts of the ball clips 82 a , 82 b , which are inserted in the clip grooves 108 and the clip holes, are covered and held by the cover plates 86 a , 86 b . Also, the cover plates 86 a , 86 b , the cover blocks 78 a , 78 b , and the guide block 76 are integrally fixed.
As a result, in a state in which the cover plates 86 a , 86 b abut against the cover blocks 78 a , 78 b , and the cover blocks 78 a , 78 b abut against end surfaces of the guide block 76 , the cover plates 86 a , 86 b , the cover blocks 78 a , 78 b , and the guide block 76 are retained together in an integrally connected fashion by the pair of cover clips 84 a , 84 b , such that relative displacement thereof in the longitudinal direction (the directions of arrows A and B) cannot occur.
In addition, the guide mechanism 16 , which is assembled as described above, is fixed to an upper part of the cylinder main body 12 through the connecting bolts 22 .
In the foregoing manner, with the first embodiment, in the guide mechanism 16 that constitutes the linear actuator 10 , by using the pair of ball clips 82 a , 82 b , the plural balls 58 can be retained in a freely circulatable condition with respect to the guide block 76 , and the pair of cover blocks 78 a , 78 b , which are in abutment against both ends of the guide block 76 , can be fixed easily by the pair of cover clips 84 a , 84 b . As a result, for example, compared to a case of being assembled mutually using bolts or the like, the guide mechanism 16 including the guide block 76 and the cover blocks 78 a , 78 b , etc., can be assembled more easily, and the structure thereof can be simplified. Therefore, in a linear actuator 10 that includes the guide mechanism 16 , the number of manufacturing steps can be reduced.
Further, in the guide block 76 , instead of providing penetrating holes through which the balls 58 circulate, a structure is provided in which ball circulation grooves 80 , which open downwardly, are formed, and the balls 58 are made to circulate through the ball circulation grooves 80 . Owing thereto, compared to the case of forming penetrating holes therein, the number of process steps as well as processing costs can be reduced. As a result, manufacturing costs for the linear actuator 10 can be reduced.
Furthermore, since the ball clips 82 a , 82 b are elastic, in a state in which the guide block 76 and the cover blocks 78 a , 78 b are installed, the ball clips 82 a , 82 b are capable of being deformed in a follow-on manner with respect to the outer circumferential surfaces of the plural balls 58 , and the balls 58 can be retained reliably in a condition that enables circulation thereof.
Further, by installation of the ball clips 82 a , 82 b in the clip grooves 108 formed on the cover blocks 78 a , 78 b , positioning of the ball clips 82 a , 82 b can be carried out easily and reliably. Therefore, it is possible for the ball clips 82 a , 82 b to always be retained at the same position with respect to the plural balls 58 , and the balls 58 can be retained in a stable manner.
Furthermore, the bulging portions 122 of the cover clips 84 a , 84 b are inserted and placed in engagement with the insertion parts 124 of the cover plates 86 a , 86 b , whereby falling out of the cover clips 84 a , 84 b with respect to the cover plates 86 a , 86 b is prevented. As a result, the cover plates 86 a , 86 b , the cover blocks 78 a , 78 b , and the guide block 76 can be kept in a connected state stably and reliably by the cover clips 84 a , 84 b.
Further still, at the same time that the pair of cover blocks 78 a , 78 b is retained by the pair of ball clips 82 a , 82 b with respect to the guide block 76 , the cover blocks 78 a , 78 b are retained by the pair of cover clips 84 a , 84 b , which are formed with a wire thickness greater than that of the ball clips 82 a , 82 b . Therefore, the cover blocks 78 a , 78 b can be fixed reliably and firmly with respect to both end surfaces of the guide block 76 .
Still further, in the guide block 76 , since the ball circulation grooves 80 in which the balls 58 are installed are disposed so as to open on the lower surface side facing the cylinder main body 12 , the balls 58 are retained by the ball clips 82 a , 82 b , and the ball clips 82 a , 82 b are retained by abutment thereof on the upper surface of the cylinder main body 12 . For this reason, even though the ball clips 82 a , 82 b may not have high structural integrity, the balls 58 can be retained reliably thereby in cooperation with the upper surface of the cylinder main body 12 .
Next, operations and effects of the linear actuator 10 , which includes the guide mechanism 16 assembled in the foregoing manner, will be explained. A condition in which the end plate 52 of the slide table 14 abuts against the end surface of the cylinder main body 12 , as shown in FIGS. 4 and 5 , will be referred to as an initial position.
First, a pressure fluid from a non-illustrated pressure fluid supply source is introduced to the first port 26 . In this case, the second port 28 is placed in a condition of being open to atmosphere under the operation of a non-illustrated switching valve.
Pressure fluid supplied to the first port 26 is supplied to one of the penetrating holes 30 a and also is supplied to the other of the penetrating holes 30 b through the connecting passages 48 , whereby the pistons 38 are pressed (in the direction of the arrow A) toward the rod holders 46 . Consequently, the slide table 14 is displaced together with the piston rods 40 , which are connected to the pistons 38 , in a direction to separate away from the cylinder main body 12 .
At this time, the balls 58 of the guide mechanism 16 roll along the ball circulation passage accompanying displacement of the slide table 14 , whereby the slide table 14 is guided in the axial direction by the guide mechanism 16 .
Then, the end of the stopper bolt 72 , which is provided at one end of the slide table 14 , abuts against the end surface of the guide block 76 of the guide mechanism 16 , and displacement of the slide table 14 is stopped, whereupon the slide table 14 reaches a displacement end position.
After loosening the lock nut 74 to enable advancing/retracting movement of the stopper bolt 72 , the amount at which the stopper bolt 72 projects from the end surface of the holder portion 64 may be adjusted by threaded-rotation of the stopper bolt 72 , whereby the displacement amount of the slide table 14 can also be adjusted.
On the other hand, in the case that the slide table 14 is displaced in a direction opposite to the above direction, i.e., in a direction away from the displacement end position, the pressure fluid, which was supplied to the first port 26 , is supplied with respect to the second port 28 , whereas the first port 26 is placed in a state of being open to atmosphere. As a result, by means of the pressure fluid, which is supplied into the pair of penetrating holes 30 a , 30 b from the second port 28 , the pistons 38 are displaced in a direction to separate away from the rod holders 46 (in the direction of the arrow B), and the slide table 14 is displaced through the pistons 38 together with the piston rods 40 in a direction to approach the cylinder main body 12 . In addition, by abutment of the damper 70 , which is disposed on the end plate 52 of the slide table 14 , against the end surface of the cylinder main body 12 , the initial position is restored.
With the above-described guide mechanism 16 , although a structure is provided that is equipped, respectively, with the ball clips 82 a , 82 b for retaining the plural balls 58 and the pair of cover blocks 78 a , 78 b , and the cover clips 84 a , 84 b for retaining the cover blocks 78 a , 78 b and the cover plates 86 a , 86 b , the guide mechanism 16 is not limited to such a structure. For example, the guide mechanism 16 may be of a structure in which the balls 58 are retained together with the cover blocks 78 a , 78 b only by the ball clips 82 a , 82 b , and which does not include the cover plates 86 a , 86 b and the cover clips 84 a , 84 b . In this case, the number of parts of the guide mechanism 16 and the number of assembly steps can be reduced.
Next, a linear actuator 150 according to a second embodiment is shown in FIGS. 11 and 12 . Constituent elements thereof, which are the same as those found in the linear actuator 10 according to the aforementioned first embodiment, are denoted by the same reference characters, and detailed description of such features is omitted.
As shown in FIGS. 11 and 12 , the linear actuator 150 according to the second embodiment differs from the linear actuator 10 according to the first embodiment, in that, in the cylinder main body 12 and the guide mechanism 16 , lubricating oil supply portions 152 are provided, which are capable of supplying lubricating oil, for example, grease or the like, to the balls 58 of the ball circulating grooves 80 .
The lubricating oil supply portions 152 are constituted from first supply grooves 154 formed in the upper surface of the cylinder main body 12 , and which extend in a direction perpendicular to the longitudinal direction (the directions of arrows A and B) of the cylinder main body 12 , and second supply grooves 156 , which communicate with the first supply grooves 154 and are formed in a lower surface of the guide block 76 of the guide mechanism 16 .
The first supply grooves 154 , for example, are disposed in plurality (e.g., four grooves) and are separated at predetermined intervals along the longitudinal direction (the directions of arrows A and B) of the cylinder main body 12 . The first supply grooves 154 are formed, respectively, on opposite sides centrally about the recess 20 of the cylinder main body 12 . Additionally, the first supply grooves 154 are recessed at a predetermined depth with respect to the upper surface of the cylinder main body 12 , and extend from both side surfaces of the cylinder main body 12 to positions facing the ball circulation grooves 80 of the guide block 76 .
The second supply grooves 156 are disposed in plurality similar to the first supply grooves 154 , and extend perpendicularly to the longitudinal direction (the directions of arrows A and B) of the guide block 76 , such that when the guide mechanism 16 is assembled on the cylinder main body 12 , the second supply grooves 156 are formed along straight lines together with the first supply grooves 154 . Further, the second supply grooves 156 extend from both side surfaces of the guide block 76 to the pair of ball circulation grooves 80 , and ends of the second supply grooves 156 are formed in facing relation to the balls 58 that are installed in the ball circulation grooves 80 .
By supply of lubricating oil from ends of the first supply grooves 154 under operation of a non-illustrated lubricating oil supply means (e.g., a grease injection tool), the lubricating oil is introduced and directed along the first supply grooves 154 to the side of the guide mechanism 16 . Also, part of the oil is introduced from the first supply grooves 154 to the second supply grooves 156 . Consequently, lubricating oil is supplied to the interior of the ball circulation grooves 80 and the plural balls 58 are lubricated.
More specifically, by supply of lubricating oil on a regular basis to the lubricating oil supply portions 152 , lubrication of the plural balls 58 can be carried out easily and reliably, and by ensuring that the balls 58 are circulated smoothly, the slide table 14 can be displaced in a smooth manner, and durability of the balls 58 can be enhanced.
Further, when lubrication of the balls 58 is carried out, since such lubrication can be carried out easily through the lubricating oil supply portions 152 without requiring disassembly of the linear actuator 150 , ease of maintenance on the linear actuator 150 can be enhanced.
Furthermore, in the guide block 76 , since the ball circulation grooves 80 in which the balls 58 are installed are disposed so as to open on the lower surface side facing the cylinder main body 12 , by disposing the first supply grooves 154 on the upper surface side of the cylinder main body 12 , lubricating oil can be supplied easily to the ball circulation grooves 80 .
Further still, the guide mechanism 16 having the aforementioned structure is not limited to a case in which a fluid pressure cylinder is used that drives the slide table 14 through the cylinder mechanisms 42 and the guide mechanism 16 , the cylinder mechanisms 42 being displaced by a pressure fluid supplied to the cylinder main body 12 , as in the linear actuators 10 , 150 according to the first and second embodiments. For example, the principles of the present invention may be applied to an electric actuator comprising the above-described guide mechanism 16 , and in which the slide table 14 is displaced along the cylinder main body 12 by a drive source such as a motor or the like.
Next, a linear actuator 200 according to a third embodiment is shown in FIGS. 13 through 19 . Constituent elements thereof, which are the same as those found in the linear actuator 10 according to the aforementioned first embodiment, are denoted by the same reference characters, and detailed description of such features is omitted.
The linear actuator 200 differs from the linear actuator 10 according to the first embodiment, in that a guide mechanism 206 is used in which the cover plates 86 a , 86 b are dispensed with, and which is equipped with ball clips 202 a , 202 b having a pair of straight portions 204 a , 204 b capable of retaining the balls 58 .
As shown in FIGS. 13 through 16 , the guide mechanism 206 includes a wide flat guide block 76 , a pair of cover blocks 208 a , 208 b disposed on opposite ends of the guide block 76 , plural balls 58 that circulate in the longitudinal direction of the guide block 76 , the pair of ball clips 202 a , 202 b that retain the balls 58 in the ball circulation grooves 80 of the guide block 76 , and a pair of cover clips 84 a , 84 b that serve to retain the cover blocks 208 a , 208 b with respect to the guide block 76 .
As shown in FIG. 17 , the ball clips 202 a , 202 b each include the pair of straight portions 204 a , 204 b constituted from a wire material, for example, made from a metal material such as stainless steel or the like, and which are formed along straight lines substantially in parallel with each other, a connecting portion 210 that connects ends of the straight portions 204 a , 204 b , and curved portions 212 a , 212 b , which are formed on other ends of the straight portions 204 a , 204 b.
The straight portions 204 a , 204 b , for example, are separated at an interval which is substantially the same as the widthwise dimension of the ball circulation grooves 80 , and are formed with a length in the longitudinal direction (the directions of arrows A and B), which is the same or slightly smaller than the length in the longitudinal direction (the directions of arrows A and B) of the pair of cover blocks 208 a , 208 b and the guide block 76 .
The connecting portion 210 is formed with a U-shape in cross section so as to connect an end on one of the straight portions 204 a and an end on the other of the straight portions 204 b , and the connecting portion 210 is formed perpendicularly to the longitudinal direction of the straight portions 204 a , 204 b.
The curved portions 212 a , 212 b are formed in a curved fashion with respect to the other ends of the straight portions 204 a , 204 b so as to bend toward the one end side (in the direction of the arrow A). One of the curved portions 212 a and the other of the curved portions 212 b are formed mutually in parallel. The ball clips 202 a , 202 b may be formed, for example, by bending a single wire material by way of press forming or the like.
The cover blocks 208 a , 208 b are disposed respectively on one end side and the other end side of the guide block 76 . On the main body portions of the cover blocks 208 a , 208 b , respective first clip grooves 214 are formed at positions along a straight line with the ball circulating grooves 80 of the guide block 76 . Together therewith, at positions on the side of the arcuate section 96 with respect to the first clip grooves 214 , a pair of second clip grooves 216 are formed for engagement with the cover clips 84 a , 84 b.
The first clip grooves 214 are recessed toward the side of the guide block 76 with respect to the end surfaces of the cover blocks 208 a , 208 b , with upper portions thereof being inclined toward the side of the guide block 76 . More specifically, as shown in FIG. 18 , from a lower end to an upper end thereof, the first clip grooves 214 are inclined at a predetermined angle toward the side of the guide block 76 .
The first clip grooves 214 are separated by a predetermined distance and extend upwardly, and between the first clip grooves 214 , projections 218 are provided with which the connecting portions 210 of the ball clips 202 a , 202 b are engaged. Upper ends of the projections 218 are formed in a semicircular shape, for example, and project outwardly at a predetermined height with respect to the first clip grooves 214 toward end surface sides of the cover blocks 208 a , 208 b.
The second clip grooves 216 are formed, respectively, to incline upwardly in directions away from the first clip grooves 214 . The second bent portions 120 a , 120 b of the cover clips 84 a , 84 b are inserted and engaged, respectively, in the second clip grooves 216 .
Additionally, when the ball clips 202 a , 202 b , and the cover clips 84 a , 84 b are mounted on the guide mechanism 206 , initially, in a state in which the guide block 76 is placed with the ball circulation grooves 80 oriented upwardly, and the plural balls 58 are installed in the ball circulation grooves 80 , the straight portions 204 a , 204 b of the ball clips 202 a , 202 b are placed in openings 220 of the ball circulation grooves 80 in abutment against outer circumferential surfaces of the balls 58 (see FIG. 19 ).
Next, the cover blocks 208 a , 208 b are disposed respectively on both end surfaces of the guide block 76 , and the second bent portions 120 a , 120 b of the cover clips 84 a , 84 b are engaged respectively in the second clip grooves 216 , whereby the pair of cover blocks 208 a , 208 b is retained on both ends of the guide block 76 . Simultaneously, the connecting portions 210 of the ball clips 202 a , 202 b are made to engage with the projections 218 on one of the cover blocks 208 a , and the curved portions 212 a , 212 b are made to engage with the first clip grooves 214 on the other of the cover blocks 208 b.
Consequently, the pair of ball clips 202 a , 202 b is retained on the pair of cover blocks 208 a , 208 b via the connecting portions 210 and the curved portions 212 a , 212 b , and the plural balls 58 are kept in a retained state in the ball circulation grooves 80 by the straight portions 204 a , 204 b . That is, an assembled condition is brought about, in which the pair of ball clips 202 a , 202 b and the cover clips 84 a , 84 b are attached with respect to the guide mechanism 206 .
In the foregoing manner, with the linear actuator 200 according to the third embodiment, since the cover plates 86 a , 86 b , which are used in the linear actuator 10 according to the aforementioned first embodiment, are unnecessary, the number of parts can be reduced and the linear actuator 200 can be made smaller in scale. Together therewith, by reducing the number of assembly steps, ease of manufacturing is enhanced and manufacturing costs can be reduced.
Further, since the balls 58 , which are installed in the ball circulation grooves 80 of the guide block 76 , are retained in a movable state along the direction of travel of the balls by the pair of straight portions 204 a , 204 b , the balls 58 can be retained securely and can reliably be prevented from dropping out from the ball circulation grooves 80 . Furthermore, due to retention of the balls 58 by the pair of straight portions 204 a , 204 b , for example, compared to a situation in which the balls 58 are retained with respect to the ball circulation grooves 80 by a single straight portion, since sliding resistance of the balls 58 can be decreased, upon movement of the slide table 14 , the balls 58 can be made to roll more smoothly along the ball circulation grooves 80 .
Furthermore, since the balls 58 are retained reliably in the ball circulation grooves 80 by the ball clips 202 a , 202 b , the openings 220 of the ball circulation grooves 80 can be formed with a large size, and ease of manufacturing can be enhanced, for example, in the case that the guide block 76 equipped with the ball circulation grooves 80 is formed by a drawing process or by forging or the like.
Further, the aforementioned ball clips 202 a , 202 b are not limited to the case of being formed from a wire material as shown in FIG. 17 . According to a modification, as shown in FIG. 20 , a ball clip 230 may be formed by press forming a plate-like member, which is made from a metal material or a resin material, for example.
The ball clip 230 comprises a ball retaining portion 232 having a predetermined width and which extends in the longitudinal direction for retaining the balls 58 , and a pair of respective bent portions 234 a , 234 b , which are bent at substantially right angles on opposite ends of the ball retaining portion 232 . The ball retaining portion 232 is formed, for example, with a flat shape, and filling grooves 236 , which are filled with lubricating oil such as grease or the like, are formed in a central part of the ball retaining portion 232 . The filling grooves 236 are disposed in plurality separated mutually in the longitudinal direction of the ball retaining portion 232 , and are recessed a predetermined depth with respect to the surface of the ball retaining portion 232 .
Upper ends of the respective bent portions 234 a , 234 b are formed with semicircular shapes in cross section, and in the centers thereof, frame-like shapes are provided in which engagement holes 238 are formed. The bent portions 234 a , 234 b are formed with substantially the same widthwise dimension as the ball retaining portion 232 .
In addition, when the aforementioned ball clips 230 are installed on the guide block 76 and the cover blocks 208 a , 208 b , in a state in which the balls 58 are installed in the ball circulation grooves 80 of the guide block 76 , after the surfaces of the ball retaining portions 232 , i.e., the surfaces on the side of the filling grooves 236 , have been arranged to face toward the balls 58 , the bent portions 234 a , 234 b are inserted respectively into the first clip grooves 214 of the cover blocks 208 a , 208 b , and the engagement holes 238 are engaged with the projections 218 .
As a result, a condition is brought about in which the ball clips 230 are retained on the pair of cover blocks 208 a , 208 b through the pair of bent portions 234 a , 234 b , and the plural balls 58 are retained inside the ball circulation grooves 80 by the ball retaining portions 232 . In addition, because the filling grooves 236 , which are filled with lubricating oil, are arranged in positions facing toward the plural balls 58 , when the balls 58 roll along the ball circulation grooves 80 , the balls 58 can be lubricated suitably by the lubricating oil.
In this manner, as a result of forming the ball clips 230 by press forming a plate-like material, the production cost of the ball clips 230 can be reduced, and ease of manufacturing thereof can be enhanced. Further, by forming the ball retaining portions 232 as flat plates, the filling grooves 236 , which are capable of being filled with lubricating oil, can be formed therein, and thus the ball retaining portions 232 can be equipped with a lubricating function for the balls 58 .
The linear actuator according to the present invention is not limited to the embodiment described above, but various alternative or additional features and structures may be adopted without deviating from the essence and scope of the invention as set forth in the appended claims. | A linear actuator includes a guide mechanism and a retainer. On a guide block of the guide mechanism, a pair of ball-circulating grooves is formed on the lower surface that faces a cylinder body. Multiple balls are loaded in the ball-circulating grooves. Paired cover blocks are respectively mounted on the two ends of the guide block. The retainer has the form of paired ball clips, which are formed as arms to engage with the cover blocks when the clips are inserted in the ball-circulating grooves to hold the balls. Paired cover plates are respectively mounted on the end faces of the cover blocks, and arm-shaped cover clips are mounted so as to hold the cover plates. The cover plates, the cover blocks, and the guide block are thereby integrally linked. | 5 |
BACKGROUND OF THE INVENTION
The movement of tracked vehicles (such as caterpillar tractors, army tanks and mining equipment) over industrial floors can result in distress of the floors in the form of cracking, spalling and a high wear rate. Traditional remedies to this problem have not been entirely satisfactory. For example, one approach has been to use iron aggregate topping materials as the wearing surface in industrial floor slabs. This concept does provide improvements in wear resistance relative to conventional portland cement concrete floors. However, even with this topping material incorporated, the floor slab is still relatively brittle and can crack and spall under severe loading conditions. Thus, there is a need in the art for industrial floors exhibiting improved resistance to cracking, spalling and wear, especially under conditions of high point loads.
SUMMARY OF THE INVENTION
This invention relates to the development of cement-based floor tiles that have shown superior performance when used under loading conditions known to cause severe wear and/or cracking in other types of tiles. This effect is achieved by incorportating large percentages of metal reinforcing fibers into floor tile composites containing a wear-resistant surfacing material.
A principal object of the invention is to provide an industrial floor that not only is resistant to wear, but also eliminates the cracking and spalling problem.
Another object of the invention is to provide industrial flooring of improved performance in the form of tiles that can be readily shipped and assembled at the site of use.
A further object of the present invention is to provide a method for manufacturing such highly wear-resistant concrete tiles.
These and other objects are attained in accordance with the present invention as heavy duty, wear-resistant concrete floor tiles in the form of precast concrete composites.
The immediate wearing surface of the composite tile (to a depth of 1/2 to 1 inch) is a concrete material containing a high percentage of metal reinforcing fibers (4 to 16 volume percent) and typically containing a high percentage (30 to 60 volume percent) of wear-resistant aggregate.
The wearing surface layer is backed up by a steel fiber reinforced concrete layer (1 to 4 inch thick) containing a high percentage of steel fibers (4 to 16 volume percent). The wearing surface layer and the back-up layer are firmly bonded together by the steel fibers common to each layer. When the wearing surface contains metal fibers as the wear-resistant additive, the substrate layer will contain a lesser amount of fibers than the wearing surface.
In practice, improved wear resistance is provided by the wearing surface layer while the overall integrity of the composite (crack and spall resistance) is afforded by the heavy fiber reinforcement in the back-up layer which carries into the wearing surface layer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a section view of the concrete composite floor tile which is the present invention. As seen in FIG. 1, the invention contains two distinct concrete layers. The thicker layer 10 is the substrate of the tile and contains a mass of fine metal fibers 12. The surface layer 20 is the wear-resistant surface of the tile and is depicted as thinner than the substrate layer 10. Certain of the metal fibers designated as 12a pass through the boundry 15 between the two layers and have one of their ends embedded in and bonded to the substrate layer 10 and have their other end embedded in and bonded to the surface layer 20.
Typically, the surface layer is a wear-resistant concrete having at least about 30 to 60 volume percent of a wear-resistant aggregate uniformly dispersed therein which prevents the concrete from completely pulverizing under the force of a high point load. The aggregates used typically have a maximum particle size of about 4 mesh (0.187 inch).
The aggregate included in the surface layer will be one or both of two principal types. The first type is a malleable metal aggregate, with iron being the principal embodiment of interest but copper, brass, aluminum and lead aggregate also being potentially useful. Iron aggregate of this type is known in the art and is commercially available for use in certain specialty concretes. The second type of aggregate that can be used is a hard mineral aggregate preferably having a Mohs Hardness value greater than 7. Suitable mineral aggregates include inorganic oxides such as aluminum oxide. Emery, fused alumina and trap rock are also useful.
While the surface layer 20 is shown in FIG. 1 as not containing fibers other than the bridging fibers 12a, in other embodiments of the invention the surface layer may also include substantial volumes of metal reinforcing fibers in amounts equaling, or exceeding, the amount of fiber in the substrate layer. Fibers in the surface layer may be "soft" metals such as copper or aluminum, which make the wearing surface malleable so that it deforms rather than pulverizes under heavy point loads.
The substrate layer is a cured concrete reinforced with metal fibers. The metal fibers preferably are carbon steel. The metal fibers may have diameters in the range of about 0.010 to 0.050 inch and have lengths in the range of about 0.75 to 3.0 inch. The metal fibers preferably also have a controlled ratio of length to diameter of at least about 50; this ratio in the art being referred to as the aspect ratio. The substrate layer contains at least 4 volume percent and preferably 8 to 16 volume percent of the metal fibers.
The surface layer is normally thinner in cross-section than the substrate layer, but is sufficiently thick to prevent spalling. As a general rule, surface layers in the range of about 0.25 to 1.0 inch are adequate. The substrate layer is typically about 1 to 4 inch thick.
The method for preparing the tiles of the invention is illustrated by FIGS. 2, 3, and 4. A tile mold 30 of any desired size is placed on a vibratory surface 25. Concrete 32, which will constitute the surface layer 20 of the tile, is poured from a container 34 into the mold 30. The quantity of concrete 32 employed will be sufficient to form a layer 1/4 to 1.0 inch in depth. The concrete 32 will be formulated to retain its fluid-like consistency for a period of about 0.5 to 1.0 hour. Referring to FIG. 3, the quantity of metal fibers desired in the substrate layer is placed in mold 32 to fill the remaining free space of mold 30. The fibers can be placed in the mold 30 in the form of a preformed mat or as loose fibers. Under the effect of the vibratory surface 25, the fibers penetrate into the preplaced surface layer 32 (which is still in a fluid state).
As shown in FIG. 4, in the next step of the process, a slurry 36 of the concrete, which will constitute the subsurface layer of the tile, is poured from a container 34 onto the bed of fibers 12. The maximum particle size of the concrete 36 used for infiltrating the fiber bed 12 must be less than the minimum spacing between the fibers. Typically, particle sizes up to 30 mesh (0.023 inch) are useful. During infiltrating of the concrete slurry, the table 25 is continuously vibrated at a low amplitude.
The cement binder in the concrete slurry is preferably portland cement, but could also be calcium aluminate cement, magnesium phosphate cement, other inorganic cements, or a polymer cement. With portland cement and calcium aluminate cement it is preferable to formulate the concrete slurry with a superplasticizer to facilitate infiltration of the fibers. Sulfonated melamine formaldehyde and sulfonated naphthalene formaldehyde are two examples of superplasticizers useful in the present invention. They are generally used in an amount of 15 to 70 ounces per hundred weight of cement.
Following the infiltration step, the cement-based composite is left to harden in the mold. After a 24 hour period (typically), the tile is removed from the mold, at which point it may be subjected to an additional curing period.
The following examples are set forth to illustrate more clearly the principle and practice of this invention to those skilled in the art.
EXAMPLE 1
Several tiles were prepared as follows:
A mold, having dimensions 2'×2'×2.5", was placed on a vibratory table. The mold was filled to a depth of 0.5 inch with an aqueous slurry of a proprietary material known as "Anvil-Top" (a product of Master Builders Corporation, Cleveland, Ohio containing portland cement and iron aggregates). The remaining depth of the mold was then immediately filled with a bed of Xorex steel fibers (Ribbon Technology Corporation, Gahanna, Ohio) in an amount to constituted 13 volume percent of the free space of the mold. The steel fibers had diameters of about 0.030 inch and were approximately 2 inch long. The fiber bed was vibrated so that a portion of the steel fibers were embedded into the Anvil-Top slurry. While vibrating, the mold was filled with a second concrete slurry having the composition set forth below:
______________________________________Component Weight Percent______________________________________Portland Cement 64Fly Ash 16Water 20______________________________________
After setting for approximately 24 hours, the finished tile was removed from the mold.
EXAMPLE 2
Example 1 was repeated except that the concrete used to prepare the surface layer had the following composition:
______________________________________Component Weight Percent______________________________________Portland Cement 27Silica Sand 12Fused Alumina Aggregate* 54Water 7______________________________________ *Mesh size -6 +14
The slurry contained about 40 volume percent of the alumina aggregate.
EXAMPLE 3
Example 1 was repeated except that the surface layer was formed by first filling the mold to a depth of 0.75 inch with 0.020 inch diameter by 0.75 inch long steel fibers to provide a loading of about 16 volume percent (in the space occupied). This fiber bed was then infiltrated with the following composition:
______________________________________Component Weight Percent______________________________________Portland Cement 59Silica Sand 26Water 15______________________________________
Thereafter, the remaining depth of the mold was filled with Xorex steel fibers as in Example 1 and these fibers were infiltrated with the same composition as above while vibrating the mold.
EXAMPLE 4
Wear tests were carried out on floor sections prepared from tiles prepared in accordance with Examples 1, 2, and 3 above. As a control, another floor section was prepared from commercial polymer concrete floor tiles having an Anvil-top wearing surface.
The tests were conducted by running a tracked coal mining machine over each of the experimental floors. The tests involved both direct runs over the tiles as well as turns carried out thereon. An equal number of runs and turns were made on each of the experimental floors with the number of runs being equivalent to about one year of normal traffic.
Inspections of the floors, made with the experimental tiles of the invention, showed no cracks or spalls in any of the tiles of the invention. Minor scoring and gouging of the surface layers of the tiles were noted, but the level of wear was deemed acceptable and of little significance. By contrast, all of the commercial tiles were badly cracked and spalled following the test.
While the method herein described, and the product thereof, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precisee method and product, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims. | A heavy duty, wear, crack and spall-resistant concrete composite floor tile comprising: a concrete substrate layer containing 4 to 16 volume percent of dispersed, fine metal fibers and, a wear-resistant concrete surface layer containing about 30 to 60 volume percent of wear-resistant, metallic or inorganic aggregate, or 4 to 16 volume percent fine metal fibers, said tile being further characterized in that the layers are bonded to each other by a plurality of metal fibers having one end embedded in and bonded to the substrate layer and the other end embedded in and bonded to the surface layer, and when said surface layer contains said metal fibers, said fibers are present therein in an amount greater than the amount of said fibers in said substrate layer. | 4 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/111,418 filed Dec. 8, 1998.
ORIGIN OF THE INVENTION
This invention was made by an employee and a contractor of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or thereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a friction stir welding apparatus comprising multiple sub-components which collectively perform as one integrated welding system allowing the apparatus to be operated and maintained in a variety of environments while permitting reduced size of the unit. The integrated nature of the sub-components gives the operator more flexibility in the type and size of workpiece that can be welded and effectively expands the utility of the friction stir welding process.
2. Description of Related Art
Friction stir welding is a method of welding based upon the principle of “rubbing” of articles to be joined together so as to generate a sufficient amount of heat. A probe of a harder material than the treated work pieces is typically applied in a welding process. The probe is subjected to cyclic movement relative to the work pieces. Merging the probe and work pieces together has been found to create a plasticized region in the work pieces due to generated frictional heat. When the relative cyclic movement of the probe stops, the plasticized material solidifies to create a weld joint.
The Friction Stir Weld (FSW) process, as it exists today, is believed to be limited to few manufacturing floors. Almost all known systems are restricted to laboratory/development environments. Development and laboratory equipment consists of large off-the-shelf machinery such as machining molds, modified to accommodate the FSW process. The large size of the laboratory equipment places size constraints upon manufacturing and tooling requirements, as a result, it is impractical and cost prohibitive to use machining mills for most manufacturing FSW applications. Additionally, the working envelope of the machining mills prohibits large pieces of hardware to be welded.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art devices in that large individual components may be replaced with sub-components attached or housed within a common base foundation unit to allow an operator to move the apparatus to the manufacturing floor where a greater range of devices can be operated on.
Accordingly, it is an object of this invention to provide a new and improved friction stir welding apparatus which permits the FSW procedure to be performed on the manufacturing floor, and in other environments that have traditionally been unavailable for use of FSW because of the size and lack of mobility of prior art FSW systems. This system may operate under loads exceeding 20,000 pounds. In addition to welding, the system can also operate as a precision controlled machining center by replacing the pin tool with an end mill/cutting tool.
An integrated welding system is taught herein which features multiple sub-components that are combined to create a self contained and mobile FSW apparatus. A base foundation unit (BFU) serves to either attach or house, or connect, other components. The BFU may be connected directly to a floor for a static welding environment or may be adopted to be mobile for dynamic weld environments. The BFU may accommodate significant axial and radial loads, estimated to be up to 20,000 lbs. or less axial and 2,000 lb. radial. An elevation platform (EP) may be movable in three dimensions and is connected to the BFU. An adjustable pin tool (APT) may be attached to the EP allowing the APT to be positioned in three dimensions . The APT may have movement independent of the EP such as rotational capabilities so it can be introduced into the weld joint at a pre-selected angle. A backplate tooling component may be attached to the exterior of the BFU to act as a backing bar during FSW weld operation. A fixturing component may be attached to the exterior of the BFU for holding and securing the workpiece during welding. A roller mechanism may be also attached to the exterior of the BFU and integrated with the APT to remove any bowing in the material before the joint is welded. Additionally, a real-time adaptive computer numerical control (CNC) and process control system (APCS) may be housed within the BFU. The APCS may be a digital computer system that incorporates common robotic position/motion control electronics and software. The APCS may also have electronics and software for monitoring the parameters of the FSW process. The APCS may analyze these parameters, and dynamically adapt the weld parameters to maintain weld performance.
In a preferred embodiment the integrated movement of the EP and the APT may be performed by hydraulics. The hydraulic system would preferably include a pump and fluid reservoir housed within the BFU. Hydraulic connections may be integrated with the EP and APT such that the operator can guide the pin tool to a desired position on the workpiece. Once the weld position is fixed, the APCS monitors the parameters of the FSW process, analyzes those parameters, and dynamically adapts the pin tool position to maintain weld performance.
Thus the friction stir weld (FSW) process as disclosed can be expanded to include a great variety of materials by integrating the individual components of large milling machines into a single integrated welding system. The process offers significant opportunities relative to costs, manufacturing, quality assurance, and health and safety standpoints for the welding of aluminum and other materials. Advantages of the process have been found to include: (1) a simple machine tool may be extremely energy efficient: a single pass 12.5 millimeter deep weld can be made in 6xxx series alloy using a gross power of less than 3 kW; (2) equipment maintenance has been found to be minimal; (3) the welding operation does not require consumable materials such as filler wire or shielding gas; (4) special pre-weld joint edge profiling may be eliminated; (5) the careful removal of oxide from the joint area immediately prior to the welding may not be required; (6) the equipment is suited for automation and integration with other machine tool operations; (7) good mechanical and metallurgical quality welds may be confidently made in aluminum alloys such as 2xxx, 5xxx and 7xx series which previously had problems such as solidification cracking and/or liquation cracking; (8) high joint strengths may be created in heat treatable alloys; (9) welds may be consistently made which are free of voids and porosity; (10) metallurgical properties in the weld material may be retained such that mechanical and fatigue properties are similar to those of the parent metal; (11) butt and lap seam welds may be created between wrought, cast and extruded materials; (12) weld repeatability is very good when weld energy input and mechanical mechanisms direct and control the working and forging of the weld metal; (13) the welding machine may be simplified to three controls: tool heel plunge depths, tool rotation speed, and welding speed; (14) health hazards such as welding fumes or radiation are severely reduced if not eliminated resulting in a clean process; and (15) alloys other than aluminum may be utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, objects and advantages of this invention will become apparent to those skilled in the art from the following description taken in conjunction with the following drawing, in which:
The FIGURE is a side elevational view of the friction weld stir weld system with interior portions shown in phantom.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the FIGURE, a friction stir weld (FSW) system 10 according to the preferred embodiment of the invention is shown. The FSW system 10 comprises a base foundation unit (BFU) 12 , an elevation platform (EP) 14 , an adjustable pin tool (APT) 16 and a process control system 18 . Additionally, the FSW system 10 may utilize backplate tooling illustrated as anvil 20 , fixturing, illustrated as clamps 22 , and a roller mechanism 24 . The FSW system 10 may be utilized for welding and weld repairs such as initial welding and weld repairs to friction weld and fusion welds (TIG, MIG, VPPA, etc.). The FSW system may also be used as a machining center by replacing the APT with an end mill.
The base foundation unit 10 may be bolted directly into a floor to create a stationery welding environment. Alternatively, the BFU 10 may be connected to at least one mobile support 28 . Mobile support 28 may comprise ways equipped with floor anchors 48 or any other suitable structure known in the art. Utilizing at least one mobile support 28 , the FSW system 10 may be utilized to create dynamic weld environments. Accordingly, the BFU 10 may be mobile. The BFU 10 may at least partially house some of the hydraulics such as the pump and fluid reservoir 30 . Additionally, the BFU 10 may house the process control system 18 which preferably comprises a real-time adaptive computer numerical control (CNC) 32 and process control system (APCS) 34 . Hydraulic connections 36 may be utilized to connect the pump and fluid reservoir 30 to the elevation platform 14 and the adjustable pin 16 .
The elevation platform 14 is preferably moveable at least along the N axis 38 which may be utilized at least partially in locating the adjustable pin tool 16 to a predetermined location. A portion of the elevation platform 14 may be housed within the base foundation unit 12 . The movement of the EP 14 may allow the pin tool 16 to be centered into a weld joint 40 for welding. In addition to movement along the N axis 38 , the elevation platform 14 may also exhibit three dimensional movement while capable of functioning under operating pressures. The movement of the elevation platform 14 may be necessary to attain proper pin tool 16 location with respect to the center of a weld joint 40 . Three axis movement may be achieved through a variety of different mechanisms known in the art.
The elevation platform 14 may also pivot relative to at least a portion of the BFU 12 . Pivot adjustments 56 and 58 may be utilized to assist in the positioning of the pin tool 16 . Additionally, the position adjustment 60 may be utilized to control movement of the elevation platform 14 along the N axis 38 . Furthermore, the process control system 18 may be utilized in conjunction with or completely replace any or all of the pivot adjustments 56 , 58 and position adjustment 60 , such as for some automated welding operations. Elevation platform 14 preferably exhibits three axes of movement capable of functioning under operating pressures. This movement has been found effective in attaining the proper pin tool 16 location respective to the center of the weld joint 40 .
The adjustable pin tool (APT) 16 is preferably directly integrated into the EP 14 . The APT 16 includes a probe which performs the friction stir welding process. The APT 16 preferably has rotational capabilities illustrated as pivoting housing 42 to allow the APT 16 to be introduced into the weld joint 40 at a preselected angle. The backing tool shown as anvil 20 may act as a backing bar during FSW weld operation. Additionally, fixturing such as clamps 22 may be utilized to hold a first and a second member 44 , 46 to be utilized to hold and secure one or more work pieces during the welding process. Additionally, a roller mechanism 24 may be utilized in conjunction with the adjustable pin tool 16 to remove any bowing in the material before the joint 40 is welded. The roller mechanism 24 may preferably have two rollers 26 which may be positioned on either side of the weld joint 40 .
The process control system 18 utilized within the FSW system 10 is preferably a digital computer system that incorporates common robotics positioning/motion control electronics and software. The APCS 34 may also have electronics and software for monitoring the parameters of the FSW process. Furthermore, the APCS 34 may also have electronics and software for analyzing the parameters of the FSW process and dynamically adapting the APCS 34 to maintain weld performance.
The FSW system 10 illustrated in the drawing shows the pin tool 16 acting along the N axis 38 . In this embodiment, the N axis 38 is illustrated as being approximately 45 degrees to a horizontal surface. The N axis 38 is shown substantially perpendicular to a first surface 50 of the BFU 10 . Alternatively, the N axis 38 could be located at other angles relative to the horizontal. Other embodiments could include the N axis 38 being substantially perpendicular to the second surface 52 or the third surface 54 of the BFU 12 .
In a preferred embodiment, the BFU 12 accommodates the internal mechanical entities of various subsystems as described above. Additionally, the BFU 12 is preferably designed to operate under the radial and axial loads associated with the FSW process. The radial and axial loads are estimated to be 10,000 pounds or less axial and 2,000 pounds radial.
The positioning and control of the pin tool 16 is believed to be a unique feature of the FSW system 10 . This FSW system 10 may be utilized for welding and weld repair on the manufacturing floor and/or a laboratory environment for a wide variety of welding and weld repair applications.
Numerous alternations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. | A friction stir weld system for welding and weld repair has a base foundation unit connected to a hydraulically controlled elevation platform and a hydraulically adjustable pin tool. The base foundation unit may be fixably connected to a horizontal surface or may be connected to a mobile support in order to provide mobility to the friction stir welding system. The elevation platform may be utilized to raise and lower the adjustable pin tool about a particular axis. Additional components which may be necessary for the friction stir welding process include back plate tooling, fixturing and/or a roller mechanism. | 1 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to a hood latch release handle for a motor vehicle, specifically a secondary latch release handle arm that is deployed longitudinally forward upon disengagement of the primary latch.
BACKGROUND OF THE INVENTION
[0002] Latch assemblies for motor vehicles are generally well-known in the art. In most motor vehicles, a hood is used to enclose the engine or luggage compartment of the motor vehicle. Such hoods are typically situated so as to be opened from the front of the vehicle and hinged along a rearward edge, such that the hood opens from the front of the vehicle. The hood is typically equipped with one or more strikers attached to the lower surface near the forward edge of the hood. The striker is situated to interact and to be restrained by the latch assembly attached to the motor vehicle chassis, likewise located proximate the forward edge of the hood. As is common in the industry, a latch release handle is typically situated in the occupant compartment, typically near the driver's side kick panel or under the instrument panel. The handle is typically connected via a bowden cable to a latch release lever operatively connected to a primary latch of the latch assembly. Upon actuation of the hood release handle in the occupant compartment, the bowden cable pulls on the latch release lever, thereby releasing the striker from the primary latch of the latch assembly. At this point, the hood is partially opened to a pre-determined height, such as about 35 to 40 mm, and is held to this position by a secondary latch.
[0003] Such secondary latches are manually operated while in front of the vehicle, such that in the event of an inadvertent release of the primary latch handle or failure of the primary latch while the vehicle is in motion, the hood will not abruptly raise due to wind pressure. Rather, the secondary latch requires an operator standing in front of the vehicle to manually operate the secondary latch to free the hood striker from the secondary latch of the latch assembly, thereby allowing the hood to be fully raised, providing access to the engine in the engine compartment and/or luggage within the luggage compartment.
[0004] Thus, in the context of such latch assemblies having primary and secondary latches, after the operator pulls the primary latch release lever from inside the passenger compartment, the hood is released from engagement with the primary latch and moved to a secondary latch release position. The operator then must move to the front of the vehicle in close proximity to the hood where the operator must then search for and locate a secondary latch release handle by inserting his or her fingers under the partially opened hood and then actuate the handle left or right (or up or down, depending the vehicle design) to release the secondary latch. The hood can then be fully opened, either manually or through some other assist mechanism, such as gas cylinders or torsion springs.
[0005] The location of the secondary latch release handle varies significantly from vehicle to vehicle. Particularly to an operator unfamiliar with the motor vehicle he or she may be operating, the secondary latch release handle can be frustratingly difficult to locate by touch alone. It is often difficult to see through the narrow, partial opening of the hood, particularly in poorly lit areas or at night. Hence, a latch assembly which overcomes these drawbacks would be advantageous.
[0006] The hood latch disclosed herein particularly accomplishes the foregoing by adapting the present typical motor vehicle hood latch assembly described above through the use of a secondary latch handle arm that is extended longitudinally forward from a retracted position to a deployed position upon disengagement of the primary latch, so that the secondary latch release handle arm is presented to the operator by forward translational motion of the extended secondary latch handle arm extending forward beyond the hood of the motor vehicle for ready actuation.
[0007] Thus, the solution presented by the present disclosure is a relatively low-cost solution that automatically presents a forward-extending and readily available secondary latch release handle arm upon the release of the primary latch, providing for convenient and confident actuation of the secondary latch release handle.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present disclosure, a motor vehicle hood latch mechanism comprises a latch assembly including a primary latch and a secondary latch. The secondary latch restrains the hood in a released position subsequent movement of the primary latch to an unlocked position. The secondary latch secures a striker to restrain the hood in a released position and allows the hood to move to an open position upon manipulation. A secondary latch release handle comprises a secondary latch release handle arm having a retracted position and a deployed position, the secondary latch release handle arm extending longitudinally forward relative the motor vehicle in each of the retracted and deployed positions, wherein the secondary latch release handle arm is extended forward of the hood to the deployed position by translational motion upon movement of the primary latch to the unlocked position.
[0009] Another aspect of the disclosure is a motor vehicle hood latch mechanism that comprises a release pawl mechanism having a release pawl rotatable between a locked position, wherein the release pawl restrains the primary latch to engage the striker, and an unlocked position, wherein the release pawl releases the primary latch from engagement with the striker, and a first resilient member urging the release pawl toward the locked position.
[0010] Still another aspect of the present disclosure is a motor vehicle hood latch mechanism, wherein the release pawl mechanism and the secondary latch release handle arm are operatively coupled to release the secondary latch release handle arm from its retracted position upon rotation of the release pawl.
[0011] Yet another aspect of the present disclosure is a motor vehicle hood latch mechanism, further comprising a secondary latch release handle arm sleeve within which the secondary latch release handle arm is slidably retained for movement between the retracted position and the deployed position, a second resilient member urging the secondary latch release handle arm to the deployed position, and a retainer releasably retaining the secondary latch release handle arm in the retracted position.
[0012] An additional aspect of the present disclosure is a motor vehicle hood latch mechanism, wherein the secondary latch release handle arm further comprises an engaging edge and the retainer comprises an engaging surface resiliently urged against the engaging edge to releasably retain the secondary latch release handle arm in the retracted position.
[0013] Another aspect of the present disclosure is a motor vehicle hood latch mechanism, wherein the engaging edge is defined in part by an inner circumference of an opening and the engaging surface is a slidable pin urged to extend into the opening by a third resilient member.
[0014] Still another aspect of the present disclosure is a motor vehicle hood latch mechanism, further comprising a release cable operatively coupled at a first end to a release pawl mechanism and coupled at a second end to the retainer.
[0015] A further aspect of the present disclosure is a motor vehicle hood latch mechanism, further comprising a pulley and wherein the release cable defines a path from the release pawl mechanism to the retainer and around the pulley.
[0016] Yet a further aspect of the present disclosure is a motor vehicle hood latch mechanism, wherein the retainer is urged to engage the secondary latch release handle arm when the secondary latch release handle is moved from the deployed position to the retracted position against the urging of the second resilient member.
[0017] An additional aspect of the present disclosure is a motor vehicle hood latch mechanism further comprising a release pawl mechanism having a release pawl rotatable between a locked position, wherein the release pawl restrains the primary latch to engage the striker, and an unlocked position, wherein the release pawl releases the primary latch from engagement with the striker, and a first resilient member urging the release pawl toward the locked position, a secondary latch release handle sleeve within which the secondary latch release handle arm is slidably retained for movement between the retracted position and the deployed position, a second resilient member urging the secondary latch release handle arm to the deployed position, and a retainer releasably retaining the secondary latch release handle arm in the retracted position, wherein the release pawl mechanism and the secondary latch release handle arm are operatively coupled to release the secondary latch release handle arm from its retracted position upon rotation of the release pawl from the locked position to the unlocked position.
[0018] Yet another aspect of the present disclosure is a hood latch comprising a primary latch releasably engaging a striker disposed proximate an edge of the hood, a secondary latch releasably engaging the striker, and a secondary latch release handle arm released to a deployed position forward of the hood by translational motion upon movement of the primary latch to an unlocked position.
[0019] A still further aspect of the present disclosure is a hood latch wherein the primary latch further has a locked position and the secondary latch release handle arm further has a retracted position, the secondary latch release handle arm extending longitudinally forward in the retracted and deployed positions, and wherein the secondary latch release handle arm moves to the deployed position from the retracted position by translational motion upon movement of the primary latch to the unlocked position.
[0020] Another aspect of the present disclosure is a hood latch further comprising a secondary latch release handle sleeve within which the secondary latch release handle arm is slidably retained for movement between the refracted position and the deployed position, a resilient member urging the secondary latch release handle arm to the deployed position, and a retainer resiliently urged to releasably retain the secondary latch release handle arm in the retracted position.
[0021] A yet additional aspect of the present disclosure is a hood latch wherein the secondary latch release handle arm is returned to the retracted position by pushing the secondary latch release handle rearwardly by translational motion until the retainer is urged to engage the secondary latch release handle arm against the urging of the resilient member.
[0022] A further aspect of the present disclosure is a hood latch further comprising an opening at a distal end of the secondary latch release handle arm within which the secondary latch release handle arm is slidably retained for translational motion between the refracted position and the deployed position, a resilient member urging the secondary latch release handle arm to the deployed position, and a retainer comprising a spring-loaded pin received in the opening to releasably retain the secondary latch release handle arm in the retracted position.
[0023] According to another aspect of the present disclosure is a hood latch for a hood having a closed locked position, a released position, and an open position, wherein the secondary latch restrains the hood in the released position subsequent movement of the primary latch to the unlocked position, the secondary latch being movable between a locked position, wherein the secondary latch secures the striker to restrain the hood in the released position, and an unlocked position, wherein the secondary latch allows the hood to move to the open position.
[0024] Still another aspect of the present disclosure is a hood latch further comprising a release pawl mechanism having a release pawl rotatable between a locked position, wherein the release pawl restrains the primary latch to engage a striker on the hood, and an unlocked position, wherein the release pawl releases the primary latch from engagement with the striker, and a resilient member urges the release pawl toward the locked position.
[0025] Yet another aspect of the present disclosure is a hood latch wherein the release pawl mechanism and the secondary latch release handle arm are operatively coupled to release the secondary latch release handle arm from its retracted position upon rotation of the release pawl.
[0026] According to a further aspect of the present disclosure, a method of unlatching a hood of a motor vehicle hood having a striker disposed proximate an edge of a hood having a closed locked position, a released position, and an open position, and comprises the steps of attaching a latch assembly to a chassis member of the motor vehicle proximate the striker for releasably engaging the striker to restrain the hood in the closed locked position, the latch assembly including a primary latch movable between a locked position, wherein the primary latch secures the striker to restrain the hood in the closed locked position, and an unlocked position, wherein the primary latch allows the hood to move to the released position, and a secondary latch restraining the hood in the released position subsequent movement of the primary latch to the unlocked position, the secondary latch movable between a locked position, wherein the secondary latch secures the striker to restrain the hood in the released position, and an unlocked position, wherein the secondary latch allows the hood to move to the open position, coupling a secondary latch release handle arm having a retracted position and a deployed position to the primary latch, the secondary latch release handle arm extending longitudinally forward relative the motor vehicle in each of the retracted and deployed positions, and moving the secondary latch release arm from the retracted position to the deployed position by translational motion by moving the primary latch from the locked position to the unlocked position.
[0027] According to another aspect of the present disclosure, the method of unlatching the hood of a motor vehicle hood further comprises the step of returning the secondary latch release handle arm to the retracted position by pushing the secondary latch release handle rearwardly by translational motion until a retainer is urged to engage the secondary latch release handle arm against the urging of a resilient member.
[0028] These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the drawings:
[0030] FIG. 1 is a front side perspective view of a motor vehicle incorporating the hood latch in accordance with the prior art;
[0031] FIG. 2 is a front side perspective view of the hood latch of the prior art with the latch placed in the locked position;
[0032] FIG. 3 is a front plan view of the hood latch of the prior art with the latch placed in the locked position;
[0033] FIG. 4A is a front plan view of the hood latch of the prior art in the locked position;
[0034] FIG. 4B is a front plan view of the hood latch of the prior art in the released and partially open position;
[0035] FIG. 4C is a front plan view of the hood latch of the prior art in the open position;
[0036] FIG. 5 is a rear perspective view of the pawl release lever of the hood latch of the prior art in the locked position;
[0037] FIG. 6 is a rear plan view of the pawl release lever of the hood latch of the prior art in the locked position;
[0038] FIG. 7 is a front perspective view of the hood latch of the present disclosure with the latch in the locked position;
[0039] FIG. 8 is an enlarged front perspective view of the secondary latch release handle and secondary latch release handle arm in the of the present disclosure with the secondary latch release handle arm in the retracted position;
[0040] FIG. 9 is a front perspective view of the secondary latch release handle arm and retainer of the present disclosure with the secondary latch release handle arm in the retracted position;
[0041] FIG. 10 is an enlarged front perspective view of the secondary latch release handle arm and retainer of the present disclosure with the secondary latch release handle arm in the retracted position;
[0042] FIG. 11 is a first front side perspective view of the secondary latch release handle arm in the deployed position; and
[0043] FIG. 12 is a second front side perspective view of the secondary latch release handle arm in the deployed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the latch as oriented in FIG. 2 . However, it is to be understood that the latch may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0045] Motor vehicle 10 includes a hood 12 covering an engine compartment 14 . Hood 12 is generally formed as a panel having a forward edge 16 and a rearward edge 18 . Hood 12 may be connected to the body of the motor vehicle 10 by hinges 20 . In the closed position shown in FIG. 1 , hood 12 is disposed adjacent and extends across an opening 22 in the body of motor vehicle 10 , providing access to an engine compartment 14 . Hood 12 is releasably connected to the motor vehicle 10 by a hood latch 30 and is pivotable relative to the motor vehicle 10 to move between an open position and a closed position. In the described example, hood latch 30 is located adjacent the forward edge 16 of the hood and the hinges 20 may be located at the rearward edge 18 of hood 12 .
[0046] Motor vehicle 10 may be provided with a deformable forward section 26 extending generally forward of the forward edge 16 of hood 12 and engine compartment 14 . It is contemplated that the deformable forward section 26 will deform upon contact with an object in a collision to absorb the impact force associated with the collision. It is also contemplated that the forward edge 16 of the hood 12 may be designed to allow for deformation upon impact with an object should the vehicle not include a deformable forward section 26 .
[0047] Referring now to FIGS. 2-9 , the latch assembly 30 is shown. FIGS. 2-6 generally show an existing hood latch 30 for a motor vehicle, while FIGS. 7-12 show a hood latch 30 equipped with the improvement disclosed herein. The hood latch 30 includes a latch mounting bracket 32 attached via mounting holes 34 to a front chassis member or base via fasteners (not shown) extending transverse and parallel to the lateral axis of the motor vehicle, as is well-known in the art. The latch assembly 30 interacts with a striker 36 disposed on the forward edge 16 of the hood 12 relative to the motor vehicle. The hood 12 has a closed locked position, a released position, and an open position. In the closed locked position, seen in FIG. 4A , the hood 12 cannot be raised and is restrained in place by a latch 38 capturing and restraining the striker 36 . The latch 38 has a primary latch portion 40 extending transversely and a secondary latch portion 42 depending from the primary latch portion 40 and normal to the primary latch portion 40 and extending in a downward direction to create a hook-shaped structure, as shown. In the release position, best seen in FIG. 4B , the primary latch 40 is released but the secondary latch portion 42 is not, thereby allowing the hood 12 to be raised, typically 35 to 40 mm. In the open position, best seen in FIG. 4C , both the primary and the secondary latch portions 40 , 42 are in the open position, and the hood 12 may be raised as described previously. The primary latch portion 40 restrains the hood 12 in the closed locked position within a channel 44 configured to receive the striker 36 , as shown. The latch 38 also includes a lower portion 46 to which a latch engagement stud 48 is attached, as will be described further below.
[0048] The latch 38 further includes a pawl engaging primary latch tab 50 and secondary latch tab 51 adapted for interaction with a release mechanism 49 comprising a release pawl 52 pivotally mounted to the bracket 32 to receive and engage the primary latch tab 50 , as best shown in FIGS. 5-6 , and a primary release lever 56 . The release pawl 52 has a latch cam engaging surface 54 and is operatively coupled with the primary release lever 56 . The release pawl 52 and primary release lever 56 are urged into contact with the latch 38 via pawl torsion spring 58 . A distal end 60 of the primary release lever 56 is connected to a bowden primary hood release cable 28 that, as described above, is in turn connected to the hood latch release lever inside the occupant compartment. A latch torsion spring 62 is provided about the pivot bolt axis 70 of the latch 38 . The latch torsion spring 62 has an upper leg 64 and lower leg 66 . The upper leg 64 is disposed adjacent the latch engagement stud 48 , while the lower leg 66 is restrained in a lower notch 68 in the bracket 32 . The latch torsion spring 62 thus urges the latch 38 into a counterclockwise rotation (as shown in FIGS. 4A-4C ) about latch pivot bolt 70 , urging the latch 38 to raise from the closed locked position to the release position and ultimately to the unlocked position.
[0049] The pawl torsion spring 58 is situated below the latch pivot bolt 70 about a pawl spring pivot bolt 72 and operates to urge the primary release lever 56 and the mechanically coupled pawl 52 into successive engagement with the primary and secondary latch tabs 50 , 51 relative to the latch cam engaging surface 54 of the pawl 52 . That is, in the closed locked position, the primary latch portion 40 engages and captures the striker 36 within the channel 44 . The primary latch tab 50 of the latch 38 is engaged by the latch cam engaging surface 54 , with both being urged into contact with one another. As the bowden cable is actuated, the primary release lever 56 is rotated counterclockwise, as seen in FIG. 4A , causing the release pawl 52 , also rotatably mounted about the pawl spring pivot bolt 72 , to rotate in the counterclockwise direction as well, thereby removing the pawl 52 from engagement with the pawl engaging tab 50 of the latch 38 . Thus, urged by the latch torsion spring 62 , the latch 38 likewise rotates in a counterclockwise direction to the first released position, shown in FIG. 4B . As the striker 36 is caught between the secondary latch portion 42 and the lower portion 46 within the channel 44 , the striker 36 is likewise placed within the hood latch 30 to a released position within the bracket 32 . While in the release position just described, the striker 36 is nonetheless restrained by the secondary latch portion 42 such that it is unable to exit from the channel 44 and is thereby restrained by the latch 38 from any further travel by the latch cam engaging surface 54 abutting the secondary latch tab 51 . However, as a consequence of having traveled upwards, the striker 36 , along with the forward edge 16 of the hood 12 , is raised approximately 35 to 40 mm above its original position. Of course, other assist mechanisms, such as gas cylinders, may be employed in addition to torsion springs.
[0050] In normal operation, the motor vehicle operator then moves to the front of the motor vehicle 10 in close proximity to the hood 12 to search for and locate the secondary latch release handle 74 by inserting his or her fingers under the partially opened hood 12 . Once located, the motor vehicle operator actuates the secondary latch release handle 74 left or right, or up or down, depending on the design. As shown, the secondary latch release handle 74 , typically a one-piece stamped component, has a substantially planar base portion 78 and a fixed, forwardly extending arm 80 and is rotatably mounted about a secondary release handle pivot bolt 76 and is displaced in a counterclockwise manner and further engages the pawl 52 to cause the latch cam engaging surface 54 to move away from the secondary latch tab 51 on the latch 38 , thus releasing the latch 38 to further rotate counterclockwise, thereby causing the secondary latch portion 42 to no longer impede the upward portion of the striker 36 . Further, with this rotation of the latch 38 , the lower portion 46 of the latch 38 urges the striker 36 in an upward direction so that the striker 36 is free of the hood latch 30 . The hood 12 may be freely opened.
[0051] However, as noted previously, the location and design of the secondary latch release handle 74 varies greatly from vehicle to vehicle. The secondary latch release handle 74 is often difficult to locate by the sense of touch alone. Moreover, it is often difficult to see the secondary latch release handle 74 through the narrow, partial opening of the hood 12 , especially in dark places or at night.
[0052] As shown in FIGS. 7-12 , a secondary latch release handle 74 that overcomes these shortcomings is disclosed. As in previous designs, the hood 12 is held in the closed position by a hood latch striker 36 operably latched to the hood latch 30 . One end of the primary hood release cable 28 is attached to the primary release lever 56 and the other end is operably attached to the inside hood release lever in the passenger compartment (not shown). As in previous designs, the hood latch 30 has a secondary release handle 74 , which when operated as described above, fully opens the hood 12 .
[0053] As can be seen in FIGS. 7-8 , the improved secondary latch release mechanism 82 comprises a secondary latch release handle 74 having a deployable, secondary latch release handle arm 84 operatively coupled with a deployable handle release cable 86 , where a first end 88 of the deployable handle release cable 86 is securely attached to the primary release lever 56 of the hood latch 30 , and the other second end 90 is securely attached to a retainer 92 , such as a spring-loaded pin 94 , that retains or holds the deployable secondary latch release handle arm 84 in a first retracted position. Pulleys 96 are provided as needed for routing the deployable handle release cable 86 about the hood latch 30 . As shown, a pair of pulleys 96 is provided.
[0054] The deployable secondary latch release handle arm 84 is thus retained by the spring-loaded pin 94 in the retracted position when the hood 12 is latched at the primary latch position shown in FIG. 4A . As can be seen in FIG. 10 , the end 98 of the spring-loaded pin 94 is inserted into an opening 100 , such as a hole or a slot, at a distal end 102 of the deployable secondary latch release handle arm 84 . The inner circumference 104 of the opening 100 thus creates an engaging edge, and the sliding end 98 of the spring-loaded pin 94 thus creates an engaging surface resiliently urged against the engaging edge to releasably retain the deployable secondary latch release handle arm 84 in the refracted position. The opening 100 is somewhat larger than the outer diameter of the spring-loaded pin 94 as required in order to allow for manufacturing tolerances, so that the deployable secondary latch release handle arm 84 is consistently retained in a secure manner. The spring 106 for the spring-loaded pin 94 can be held securely in position by welding or fastening it to the latch mounting bracket 32 .
[0055] As shown in FIG. 8 , the deployable secondary latch release handle arm 84 is held in position by a deployable secondary latch release handle arm sleeve 108 . The deployable secondary latch release handle arm sleeve 108 is securely attached (such as by welded, bonded, or fastened) to the base portion 78 of the secondary latch release handle 74 . The deployable secondary latch release handle arm sleeve 108 also allows the deployable secondary latch release handle arm 84 to slide within its slot 110 from the retracted position, as shown in FIGS. 7-8 , to a deployed position, and vice versa. The deployable secondary latch release handle arm 84 is held in this retracted state against the urging of a deployable secondary latch release handle arm spring 112 . One end 114 of the deployable secondary latch release handle arm spring 112 is attached to the fixed deployable secondary latch release handle arm sleeve 108 and the other end 116 is attached to the distal end 102 of the deployable secondary latch release handle arm 84 .
[0056] Referring to FIG. 10 , it can be seen that the deployable secondary latch release handle arm spring 112 is at an extended or energized state when the deployable secondary latch release handle arm 84 is in the retracted position, which in turns places a forward force on the deployable secondary latch release handle arm 84 . This forward force on the deployable secondary latch release handle arm 84 is in turn resisted by the spring-loaded pin 94 and opening 100 , which retain the deployable secondary latch release handle arm 84 in the retracted position by engagement of the spring-loaded pin 94 with the opening 100 .
[0057] In operation, as the motor vehicle operator pulls on the passenger compartment hood release lever, the primary hood release cable 28 attached to it pulls on the primary release lever 56 , which in turn releases release pawl 52 , which thereby releases the primary latch portion 40 to allow the striker 36 to engage the secondary latch 42 and which allows the motor vehicle operator to partially open the hood 12 . The act of pulling of the primary hood release cable 28 by the motor vehicle operator and the pulling of the primary release lever 56 also simultaneously pulls the deployable handle release cable 86 , due to its attachment to the primary release lever 56 . This action of the deployable handle release cable 86 then pulls the spring-loaded pin 94 from engagement with the opening 100 on the deployable secondary latch release handle arm 84 .
[0058] FIGS. 9 and 10 show the subsequent action of the deployment of the secondary release handle arm 84 . As the spring-loaded pin 94 is pulled away and is disengaged from the opening 100 in the deployable secondary latch release handle arm 84 , the deployable secondary latch release handle arm 84 then deploys forward in purely translational motion by sliding within the slot 110 of the secondary deployable latch release handle sleeve 108 toward the outside of the motor vehicle 10 through the partial opening of the hood 12 due to the urging of the deployable secondary latch release handle arm spring 112 . The deployable secondary latch release handle arm spring 112 then reverts back to its contracted and non-energized state, and the deployable secondary latch release handle arm 84 is thus presented to the motor vehicle operator outside and forward of the hood 12 in its deployed state. FIGS. 11 and 12 show a rendition of such deployment and the deployable secondary latch release handle arm 84 in its forward extended position. The motor vehicle operator may then actuate the deployable secondary latch release handle arm 84 , along with the secondary latch release handle 74 , to the left or right (or up or down, depending on the latch design) and fully open the hood 12 .
[0059] To close the hood 12 , the motor vehicle operator simply pushes the deployable secondary latch release handle arm 84 back to its retracted position. The distal end 102 of the deployable secondary latch release handle arm 84 may have a curved bent portion 118 , and the end 98 of the spring-loaded pin 94 may be chamfered in such a way as to facilitate the sliding of the spring-loaded pin 94 along the length of the deployable secondary latch release handle arm 84 until the end 98 of the spring-loaded pin 94 re-engages the opening 100 in the deployable secondary latch release handle arm 84 . The deployable secondary latch release handle arm 84 is then thus reset to its retracted position and energized for future deployment. The motor vehicle operator can now close the hood 12 using normally accepted hood closing process.
[0060] The present disclosure thus describes a secondary latch release handle 74 that is selectively extended longitudinally forward after disengagement of the primary latch 40 , so that the secondary latch release handle 74 is presented to the operator by only translational motion of the extended secondary latch release handle 74 . Where the hood 12 is in or nearly in the same substantially horizontal plane as the front fascia, as is becoming a more modern trend, the hood 12 in the partially opened position thereby presents a very narrow opening within which to deploy the secondary latch handle 74 . The disclosure overcomes this disadvantage by using purely translational motion of the extended secondary latch handle 74 . Further, the lack of rotational motion and the lack of a cam-engaging surface to deploy the deployable secondary latch release handle arm 84 eliminate wear and potential malfunction of the secondary release handle 74 over time.
[0061] A further advantage of the present system is that the system and method can be adapted to an existing hood latch 30 by replacement of but a few components. The normal operation of the existing hood latch 30 will not be affected by secondary latch release handle arm 84 of the present disclosure, and the deployable secondary latch release handle arm 84 will only be activated when the primary latch portion 40 is released. Another further advantage of the present system is a secondary latch release handle 74 that requires minimum package volume and therefore has a minimum footprint normal to the vehicle front plane.
[0062] The secondary latch release handle 74 disclosed here thus automatically extends outside of the motor vehicle 10 through the partial opening of the hood 12 when the operator disengages the primary latch portion 40 . The operator then simply actuates the deployable secondary latch release handle arm 84 left or right (or up or down per the latch design intent) and fully opens the hood 12 . There is no need to kneel down, look for the handle under the hood 12 in darkness, or try to feel for it blindly and locate it by using one's fingers. Actuation action is also unhindered as there are no space constraints outside of the vehicle 10 to interfere with operation of the secondary latch release handle arm 84 .
[0063] It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. | A motor vehicle hood latch mechanism comprises a latch assembly including a primary latch and a secondary latch. The secondary latch restrains the hood in a released position subsequent movement of the primary latch to an unlocked position. The secondary latch secures a striker to restrain the hood in a released position and allows the hood to move to an open position upon manipulation. A secondary latch release handle comprises a secondary latch release handle arm having a refracted position and a deployed position, the secondary latch release handle arm extending longitudinally forward relative the motor vehicle in each of the retracted and deployed positions, wherein the secondary latch release handle arm is extended forward to the deployed position by translational motion upon movement of the primary latch to the unlocked position. | 8 |
FIELD OF THE INVENTION
The invention pertains to the field of surround sound. More particularly, the invention pertains to circuits used to encode or decode "presence" or "surround" information in stereo audio sources.
BACKGROUND OF THE INVENTION
In the average movie theater, two types of "surround" systems are used-the 70 mm 6-track magnetic system, and the more common 35 mm optical arrangement. The former uses a magnetic strip attached to the film to supply six discrete channels, and the latter uses two optical audio tracks. This two-channel system is the basis for home surround sound decoders.
Every stereo videodisc, tape and MTS broadcast that was surround encoded still contains the same rear channel information as the two-channel magnetic master from which the theatrical 35 mm optical soundtrack was produced. In other words, your stereo videotape or disc of Star Trek I, II, II, Raiders of the Lost Ark, Superman and Star Wars can be decoded to produce surround sound at home. In addition, LPs, CDs and any stereo audio material can benefit from surround sound decoding. Ambiance extraction is a pleasant side effect that many decoders provide. In a nutshell, if the recording was made in a large hall, or a small club, "surround sound" will reproduce the recording environment faithfully.
Assuming the listener is seated centered between the two speakers, sound which is recorded "in phase" and with equal amplitude in each channel in a standard stereo system will appear to the listener to be located equidistant between the two speakers, as the two in-phase audio signals add together. The sound can be shifted left-to-right by varying the ratio of the amplitude of the left and right signals.
"Out of phase" signals, on the other hand, tend to cancel each other out. If a signal is recorded at equal amplitude on each channel of the stereo but 180°out of phase, the listener would ideally hear nothing, as the two signals cancel each other out. As a practical matter, the signals are audible, but sound odd.
By subtracting the left and right signals (L-R), the in-phase signals will be cancelled, and the out-of-phase signals are recovered. This is the basis of the "matrix encoding" which is used to record surround information which is inaudible to listeners with conventional stereo equipment.
"Dolby Surround", a proprietary technique of Dolby Laboratories, inc., is the current standard for multi-channel movie sound. The Hollywood mixers start with a conventional stereo soundtrack, which has one left channel and one right. By using some of Mr. Dolby's black boxes, they drop in two more "matrix"-encoded channels--one for the front center channel (used mainly for dialogue), and one for the rear surround channel (used mainly for effects). The rear-channel sound information is mixed "out-of-phase" into both stereo channels ("left-minus-right"), and the center-channel information is derived from the information common to both stereo channels ("left-plus-right").
The center and surround channels must then be decoded from the encoded stereo signal. The center and rear (surround) signals are then reproduced on speakers located between the normal front stereo speakers and behind the listener, respectively.
There are many surround sound decoders on the market today. The simplest of them is the Dynaco model QD-1, which is a version of the decoder described in a 1970 Audio Magazine article by David Hafler for use with the then-emerging quadrophonic sound technology (which has since been abandoned). Hafler's U.S. Pat. No. 3,697,692 is essentially the same as the Dynaco QD-1. The Hafler system operates at high levels - that is, the speaker output from the left and right amplifiers is divided among the four speakers, with the (L+R) center speaker connected between the "-" terminal of the L and R speaker and ground, and the (L-R) rear speaker connected across the "+" terminals of the L and R speakers.
Ranga, U.S. Pat. No. 4,132,859, is another high-level system, which is a further development of the Hafler system.
Very good results can be obtained with the Hafler system. However, all high-level systems have a number of basic problems, not the least of which being the expense of using high-power components (L-Pads) to balance the system. Also, the balance controls on the amplifier must be carefully set, using a mono signal, for minimum surround channel output, and then left strictly alone. Any change in the amplifier balance destroys the surround effect.
Most surround decoders currently on the market operate at "line level". That is, they take the left and right signals at preamp level, before they are fed into the final amplifiers. This requires a second set of amplifiers for the two derived channels, but eliminates the need to deal with the power requirements of a high-level decoder. Since the surround channel signals are decoded at constant preamp level, the balance controls on the amplifier (after the decoding) have no effect on the decoding.
All of the low-level decoders known to the inventor use active components (transistors, operational amplifiers, etc.) to decode the surround information from the stereo source. The original decoders were primarily analog circuits, such as may be seen in Holbrook, U.S. Pat. No. 4,612,663, Ito, et.al. (Sansui), U.S. Pat. No. 3,757,047, or Iida (Sony), U.S. Pat. No. 3,725,586. Other low-level active analog systems are Ohta, et. al. (Victor of Japan), U.S. Pat. No. 3,745,254 (using frequency-dependent phasing), Ito, et. al, (Sansui) U.S. Pat. No. 3,761,631 (phase modulates rear channels at an ultra-low frequency rate).
More modern higher-end units today tend to use digital signal processing to achieve the same results. Various kinds of filtering, noise reduction, reverberation, and other effects are often built into these units. All of this adds to the expense and complexity of the decoders. For example, the SONY TAE-1000ESD Surround-sound Processor/pre-amp lists for approximately $1000, and offers a wealth of digital-processing modes, including one of the finest overall surround-sound decoders available; the LEXICON CP-1 Surround-sound Decoder lists for $1250, and has true Dolby Pro-Logic Surround circuitry, 16-bit digital delay, two audio/video inputs, and a full-function wireless remote control. The CP-1 also features an "auto azimuth correction" mode designed specifically to prevent dialogue from leaking into the rear channel, and a number of digital signal processing effects modes.
All of these active decoding systems, especially the digital ones, involve complicated and expensive electronics, and relatively high prices.
The Dolby Surround System introduces a digital delay into the surround (rear) channel. There are several reasons advanced for this. One is to delay the rear signal so that the front and rear signals arrive at the listener's ears at the same time. This would appear to be a poor technique, since it would depend entirely on where the listener sits relative to the two sets of speaker. Others suggest that the "Haas effect" causes a listener to localize sound to the direction it is heard first. By delaying the rear sound by a fixed amount, usually 20 milliseconds, the listener is tricked into hearing the sounds as being primarily front/center, and the effect of stray sounds being erroneously shifted to the rear is minimized. Some units add a variable delay control, which allows the user to change the length of the fixed delay, but whatever the user chooses, the delay remains fixed at whatever the chosen length is.
Twenty milliseconds is the period of one cycle at a frequency of 50 Hz. This means that the only sounds which are correctly phased with a 20 ms delay system are those which are even multiples (harmonics) of 50 Hz. All others are to a greater or lesser degree out of phase. Frequencies between the peaks can be greatly attenuated or cancelled completely due to out-of-phase mixing. This creates a situation which is every audio engineer's nightmare--an overall system response with a peak in every octave, caused by speakers which are in phase only near certain frequencies. It is advantageous, then, to eliminate the use of delays in the surround sound decoding.
SUMMARY OF THE INVENTION
The invention presents a passive circuit for surround-sound decoding using a transformer having center-tapped primary and secondary windings. The line level left and right signals are introduced into the primary winding, and the center tap of the primary supplies a left-plus-right center channel output. The secondary center tap is grounded, and the winding connections supply left-minus-right and right-minus-left surround outputs.
The same circuit can be used for recording surround sound onto a two-channel (stereo) medium. A center microphone is connected to the center tap of the primary winding. Left and right surround microphones are connected to the secondary winding, which has its center tap grounded. The left and right recorder inputs are connected to the opposite sides of the primary winding.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a block diagram of the circuit in use.
FIG. 2 shows a schematic of the circuit of the invention.
FIG. 3 shows the circuit in use to record surround sound.
FIG. 4 shows an alternative connection of the circuit as used to record surround sound.
FIG. 5 shows the circuit as used to modify or create surround sound on recordings which were not originally recorded with the surround information.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 shows the circuit of the invention. As can be seen from that figure, the basic element of the circuit is an audio transformer (38) which has primary (42) and secondary (43) windings. Each of the windings is equipped with connections at each end: (39) and (41) on the primary, and (44) and (46) on the secondary windings. Each winding also has a center tap connection midway between the end connections: (40) on the primary and (45) on the secondary.
The transformer can be any audio type having suitable impedance characteristics for the application. For the typical preamp input/output situation with current technology audio equipment, it would be recognized by one skilled in the art that input impedances in excess of 1KΩ, and outputs at or below 1KΩ would be appropriate. Other applications, or changes in standards in the future, might require other impedance ranges, which would be within the ability of one skilled in the art to select.
Because the circuit operates at low power levels (that is, at the preamp input levels rather than amplifier output levels) it is preferred to use a small, low power transformer for economic and space reasons.
The preferred embodiment of the invention uses a transformer having a primary (input) winding of 10KΩ impedance (5KΩ each side of center tap) and a secondary winding of 2KΩ impedance (1KΩ each side of center tap). Such a transformer may be purchased from Triad, selected from series number SP-21, which is a series of small transformers, specifically model TF5S21ZZ.
Since low bass sounds are essentially non-directional, there is no need to pass these frequencies through to the surround channels. Therefore, the preferred transformer has frequency characteristics which are flat above 300 Hz, and which roll off -3 dB at 200 Hz, and essentially cut off frequencies below 100 Hz.
The right (30) and left (31) channels of the stereo signal having the out-of-phase surround information is supplied to the primary of the transformer at the end connections (39) and (41), respectively. To make the connections to the audio equipment easier, left (32) and right (33) front outputs are connected directly to these inputs, so that the front channel sound information can be taken from the source, "looped" through the box containing the circuit of the invention, and routed to the inputs of the front channel amplifier. It will be understood that these outputs can be dispensed with, if the outputs of the signal source are connected to the circuit and the front amplifier using "Y" patch cords to parallel the inputs.
If desired, a number of input connectors can be provided, for multiple signal sources such as VCR's, CD players, stereo or TV tuners, etc. In such cases a double-pole multi-throw switch would be included to switch left/right input pairs to the left (30) and right (31) inputs to the circuit.
Ganged potentiometers (47a) (47b) may be included as system master volume control to control overall level of the the front and center/rear (surround) speakers. The potentiometers are tapped (48) at 40% from the grounded end, and a 2.2KΩ resistor (49) and 0.047 μf capacitor (80) is in series to ground to provide a loudness compensation. The capacitor (80) is shorted by switch (81) to defeat the loudness compensation.
The center tap (40) of the primary winding (42) supplies the in-phase sum of the two input signals (Left+Right) to a center channel output (36). Since this center tap is connected through the primary winding to the left and right inputs at the ends of the primary winding, the center channel output (36) has DC continuity with the two input channels. In other words, the 100 Hz cut-off does not apply to the center channel signal. Thus, the center output (36) may be paralleled with a sub-bass output (37), which can be used to drive a sub-woofer amplifier. Since sub-bass audio is non-directional, only one sub-woofer speaker on the L+R signal is required, rather than separate Left and Right Sub-woofers.
The secondary winding (43) supplies difference signals (L-R) and (R-L) for driving Left Rear (34) and Right Rear (46) outputs from the end connections (35) and (46), respectively. These two outputs are identical, but 180°out of phase with each other. The center tap (45) of the secondary winding (43) is grounded.
This difference signal extracts the out of phase surround information from the Right and Left input signals, and the sum signal cancels the surround information and passes the in-phase front channel information.
That is, if a sound source is to appear in center front, it is mixed by the film audio editors equally, in phase, to the left and right channels. If the signal is denoted as "X" then X+X (the L+R center channel)=2X. On the other hand, X-X (the L-R rear surround channel)=0, or no signal.
If a sound source is to appear only in the rear (surround) speaker(s), it is mixed, out of phase, equally onto the left (L) and right (R) signals - i.e. X to the left channel and -X to the right (or vice versa). Then, the center channel (L+R) will have no signal: X+(-X)=0. The rear (surround) channels (R-L) and (L-R), however will have the signal reproduced: X-(-X)=2X, and (-X)-X=(-2X).
FIG. 1 shows how the circuit of the invention is used in a surround-sound home theater system. The system comprises a stereo TV set (1) used for display of the TV picture and for amplification of the front channel audio, a tuner/vcr (2) which supplies the video and audio signals for the system, the surround decoder of the invention (3) and a stereo amplifier (4), used to amplify the surround and center channel audio.
In the preferred embodiment shown, five speakers are used: left (6) and right (7) front, center (8) and left (9) and right (10) rear/surround. They are shown as they would be placed around the listener (5). The center (8) speaker would normally be put facing the listener (5) either immediately above or below the TV screen. The front left (6) and right (7) speakers would flank the TV screen, perhaps 6 feet or so apart, facing the listener (5). The surround speakers (9) and (10) are behind the listener (5), preferably facing inwards.
The video output (13) of the tuner/vcr (2) is connected to the video input (12) of the stereo TV (1). The left and right (17) audio outputs of the tuner/VCR are fed into the decoder (3), and "loop" through to the audio inputs (14) of the stereo TV (1) which then drives the left (6) and right (7) front speakers from its left (11) and right (16) speaker outputs. If desired, a discrete stereo amplifier could be used to drive the front speakers in place of the audio system in the TV set.
Since the left (34) and right (35) surround outputs from the decoder (3) are the same, except 180°out of phase, it is not necessary to separately amplify the two. Optionally, only one (35) may be used as an input to one channel (21) of the stereo amplifier (4). The corresponding output (26) of the amplifier feeds the right (10) surround speaker directly, and the left (9) surround speaker is connected in parallel, but with the wires reversed. The reversed wires result in an audio signal which is 180°out of phase, or the same as that produced by the other surround output from the decoder. This connection allows the other channel of the stereo amplifier (23) to be used to amplify the center channel output (36) of the decoder (3) and drive center speaker (8).
If the user desires, the two surround speakers could be replaced by a single bipolar (bi-directional) speaker centered behind the listener.
A sub-woofer amplifier and speaker (not shown) could be connected to the sub-bass output (37) of the decoder. Since sub-bass sound is not directional, the subwoofer could be placed anywhere convenient in the room.
The decoder circuit of the invention can be used, in reverse, to record stereo audio with surround information. FIGS. 3 and 4 show the circuit in use in such an application. The recorder (5) could be an audio recorder, or a video camera/recorder with stereo audio.
In the configuration shown in FIG. 3, three microphones--center (54), left surround (53) and right surround (56)--are used to record the sound. The configuration of FIG. 4 is otherwise identical, but uses one bipolar microphone (63) (such as a ribbon microphone) to record the surround information.
The center microphone can be the conventional microphone on the camcorder, or could be a remote microphone centered on the subject (i.e. actor or stage) and transmitting back to the camcorder by an IR or RF link. In any event, the center microphone is used to record the subject, dialog, etc.
The surround microphone(s) record the ambiance/surround information. They would preferably be placed on the camcorder or behind it, pointed outwards.
The left and right record inputs (51) on the recorder (50) are connected to the end connections of the primary winding (60) of the transformer (58). The center microphone (54) signal is connected to the center tap (52) of the primary winding, possibly through a balance control (55). As before, the center tap of the secondary winding (62) is grounded.
If there are two surround microphones (FIG. 3) (53) and (56), they are connected to the end connections (57) and (61) of the secondary winding of the transformer (58). If one bipolar microphone (FIG. 4) (63) is used, it is connected to one of the end connections (57) of the secondary winding of the transformer, and the other is left unused.
FIG. 5 shows how the circuit may be used in pairs, back to back, to modify existing stereo recordings to incorporate a simulation of surround sound (sometimes called "magic surround").
The source input (70) is fed into the end connections of the primary winding (76) of first transformer (71). The outputs from this transformer are the L+R sum signal from the center tap (83) of the primary winding of the first transformer (71) and the L-R difference signal from one end connection (75) of the secondary winding. The center tap of the secondary (81) is once again grounded, and the other end connection (79) of the secondary is unused.
The sum and difference signals are fed into the two channels of a stereo mixer (74a) (74b). The sum signal is simply amplified by one channel of the mixer and passed on to the center tap (84) of the primary winding of the second transformer (72). The end connections of the primary winding (78) of the second transformer (72) become the input (71) to a recorder.
The difference signal (L-R) passes through the other channel of the stereo mixer (74) and to one of the end connections (77) of the secondary winding of the second transformer (72). The other end connection (80) is unused, and the center tap (82) of the secondary is grounded.
This arrangement can create surround effects through the use of a reverberator (73) in the difference signal channel of the stereo mixer (74a). By separating sum and difference signals in the first transformer (71), adding reverb or other effects to the difference channel in the mixer (74), then recombining the signals in the second transformer (72), left and right output signals (71) with a simulation of surround sound can be created. The input to the reverb may be taken from the center channel mixer (74b) which will provide a realistic surround effect.
Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments are not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention. | A passive circuit for decoding surround-sound signals using a transformer having center-tapped primary and secondary windings. The line level left and right signals are introduced into the primary winding, and the center tap of the primary supplies a left-plus-right center channel output. The secondary center tap is grounded, and the winding connections supply left-minus-right and right-minus-left surround outputs. The same circuit can be used for recording surround sound onto a two-channel (stereo) medium. A center microphone is connected to the center tap of the primary winding. Left and right surround microphones are connected to the secondary winding, which has its center tap grounded. The left and right recorder inputs are connected to the opposite sides of the primary winding. | 7 |
FIELD OF THE INVENTION
The present invention relates to computer controlled pipeline monitoring and, more specifically, to multiple monitoring stations which may each include cathodic test leads for detecting pipe/soil potentials, a pipeline pig detector, a pipe damage detector, and a satellite communications module for communication with a central monitoring facility.
BACKGROUND OF THE INVENTION
Pipelines are utilized throughout the world to transport a variety of liquid products, including oil, petroleum products, natural gas, and chemicals. Over a period of time, contaminates or residues accumulate on the inner walls of the pipe, thereby reducing pipeline flow efficiency. In order to extract the build up, an internal traveler known as a pig is propelled through the pipe. Besides cleaning the interior walls of the pipe, pigs are useful for pipe gauging, line fill and de-watering, product separation, leak detection, and corrosion, internal thermal, and/or video surveys.
Because pigs are susceptible to becoming obstructed within the pipe, knowing the location of the pig is critical. In order to ensure accurate location, it is necessary to monitor the pig's progress during pumping (pig propelling) operations. Noise making devices, such as chains or wall tapping devices, have been used to track the location of pigs. However, this method is expensive since crews of technicians stationed at points along the route of the pipeline are required to listen for the pig. Low frequency electromagnetic transmitters have been attached to the pig, but these require on-board power, which is susceptible to failure or power loss. In some countries, hazardous radioactive tracers are used. Offshore operators use pingers, which provide periodic sonic pulses. The seawater acts as a conductor of the sonic pulse for a surface receiver. Using the above techniques, receiving a locating signal from the pig was often unreliable.
Pig monitoring stations were developed to indicate the passage of the pig along a point, or station, of the pipeline. A mechanical signaling device was inserted into a small hole of the pipeline, allowing a lever to hang down into the pipe. Upon the passage of the pig, the lever was hit which set a visual flag on the external surface of the pipe. Later, micro-switches were added which sent a closure signal to a console to indicate passage of the pig. Although these mechanisms provide location data, the intrusion created for the mechanical signaling device undesirably affect the integrity of the pipeline since the entire system must be shut down for maintenance of the pig passage signaling device.
Non-intrusive pig detector mechanisms were developed which used magnetic passage indicators and a permanent magnetic circuit that became part of the pig's construction, becoming a “magnetic pig”. The magnetic circuit could be attached to most types of pigs, including inflatable spheres. The magnetic pig created a magnetic field sufficient to saturate the wall of the pipe through which the pig is traveling. Magnetic passage indicators, placed along the length of the pipeline and in close proximity to the pipe wall, allowed the operator to track the pig through the pipeline. Each magnetic passage indicator signaled the pig's arrival and indicated the time of the event. A subsea passage indicator included the ability to transmit the signal either acoustically or via an underwater umbilical to the surface. Permanently mounted passage indicators were adapted to radio telemetry.
Sensitive magnetic sensing instruments, such as flux-gate gradiometers, have been utilized successfully to locate the pig, provided the pipeline is not buried too deep. In marine applications, a diver equipped with a marine flux-gate gradiometer is commonly used to locate the pig. These techniques have significant disadvantages in that they use significant personnel to perform the search and hopefully locate the pig.
All forms of pigs are susceptible to becoming lost or obstructed during their travel from one section of the pipeline to another. Once found, the pig can be extracted or corrected. Since magnetic passage indicators provide indications to locate the pig between two known points with time-of-event data, the pig can be accurately tracked. However, the distance between magnetic passage indicators may be as great as several miles, and the expense of locating the lost pig includes high personnel costs and long delays, leading to lost production. A more efficient and timely determination of the pig's position is desired to reduce personnel costs and down time.
Inspection pigs are used to detect the extent of corrosion in oil and gas pipeline systems. The most common type of inspection pig is the magnetic flux leakage pig (MFL) which utilizes a strong magnetic field to saturate the wall of the pipe as the pig travels along the pipeline. Magnetic sensors positioned around the body of the pig detect deviations in the magnetic field, thus indicating pitting or corrosion of the wall of the pipeline. After detection of corrosion, it has been a problem to accurately identify, within a few feet, the location of the pig along the pipeline when the corrosion signal was obtained. An odometer has been used to count the footage traveled from the start of the operation. However, odometers may “skid”, causing erroneous information. A higher degree of accuracy has been obtained utilizing an internal timer synchronized to the Global Positioning System (GPS) time prior to the launch of the pig. As the pig passes magnetic markers at monitoring stations which have been surveyed into GPS coordinates, the marker captures the event time. After the completion of the pig's survey run, the timing of the passage indicators is compared with the internal clock and the events detected by the inspection pig, thereby providing a more accurate indication of the location of pitting or corrosion along the pipeline.
In addition to concerns regarding pitting or corrosion of the internal pipe wall, corrosion also may occur on the outer wall or skin of the pipeline. Pipelines are protected from external corrosion by insulating the outer skin of the pipe from the earth using a coating or protective wrapping. Due to insufficient wrapping protection, the integrity of the cathodic protection at sections along the pipeline route may be susceptible to corrosion. In addition, a low voltage, typically −1.2 vdc, is applied to the pipe relative to ground. Current producing systems, known as cathodic protection rectifiers (CPRs), are positioned at strategic points along the pipeline route. CPRs produce a low voltage and a high amperage which is continuously applied to the pipeline. Cathodic test leads connected to the skin of the pipeline and to ground at these stations detect pipe/soil potentials with a voltmeter. A negative voltage between −1.2 vdc and −0.85 vdc is generally considered acceptable. Cathodic test lead stations may also provide a direct connection to the pipeline and a protective casing surrounding the pipeline. Protective casings are used at road crossings and are insulated from the wall of the pipeline. By utilization of a half cell electrode coupled to a volt meter and connected to the test lead station, pipe/soil potentials can be obtained. A negative voltage between −1.2 vdc and −0.85 vdc is generally considered acceptable. Most CPRs are monitored for voltage, amperage and meter readings. Cathodic test lead stations are typically positioned at one-mile intervals, or at stations of easy access, e.g., pipeline warning sign locations and road crossing locations. Operators routinely visit these cathodic test lead stations at monthly intervals to obtain pipe/soil potentials, thereby ensuring reliability of the cathodic protection system.
Contractors digging close to pipelines may inadvertently damage a pipeline. Damage to the pipe protective wrapping often leads to corrosion, which is the major cause of pipeline leaks or blowouts. Also, attacks to the pipeline by terrorists or illegal tapping of the pipe contents can cause severe disruption to the pipeline system.
Obtaining monthly data cathodic test lead stations is labor intensive, and prevents technicians from performing other pipeline duties. Moreover, this labor intensive staff typically experience long driving hours under variable weather conditions. Pipeline operators recognize that many driving accidents occur in the pipeline industry because of the need to periodically monitor the cathodic test lead stations.
The disadvantages of the prior art are overcome by the present invention, and the improved pipeline monitoring system is hereafter disclosed.
SUMMARY OF THE INVENTION
A pipeline monitoring system according to a preferred embodiment includes a series of monitoring stations positioned along a pipeline. Each monitoring station is capable of communicating with a central monitoring facility, both for transmitting commands to the monitoring station and for receiving monitoring signals at the central monitoring facility. The monitoring station may be responsive either to a command from the central monitoring station, or to a computer with a pre-programmed event time at the monitoring station, or to a magnetic pig detected at the monitoring station as it is passed through the pipeline.
Each monitoring station may include a computer, a communications modem, input/output modules and a magnetic sensing module. The computer is adapted to receive a number of input/output modules which are individually configured to interface to a wide variety of measuring instruments and control equipment for the measurement of, e.g., pipeline pig detection, pipe/soil potentials, pipeline damage detection, CPR current, voltage, and meter readings, and valve monitoring and activation. The communication module interfaces the monitoring station to the central monitoring facility through a satellite communications network, preferably the Low Earth Orbiting (LEO) satellite system, so that the pipeline can be monitored in real time without requiring technicians at each monitoring station.
It is an object of the present invention to provide an improved method of monitoring magnetic pipeline pigs and/or obtaining pipe/soil potentials and/or detecting pipeline damage, thus saving pipeline operators labor and reducing driving accidents.
It is a feature of the present invention that each monitoring station includes a satellite communications module for interfacing with a LEO satellite system. A related feature of the invention is that the central monitoring facility includes a control station to output command signals to the plurality of monitoring stations. Each of the plurality of monitoring stations may also include a computer for outputting an activity signal to operate the monitoring station.
Another feature of the invention is that the satellite communications module outputs a time signal in response to the magnetic pig position detector, so that the central monitoring facility may easily determine the location and the speed of the pig moving through the pipeline. The pipeline monitoring system may also include digital-to-analog converters, analog-to-digital converters, and a reset circuit for applying opposite current pulses to the magnetic pig position detector.
Still another feature of the invention is that satellite communication module outputs pipe/soil potentials at periodic intervals to the central monitoring facility. Pipe/soil potentials from the number of monitoring stations may be obtained substantially simultaneously, so that comparisons between potentials at different locations can be analyzed. Pipe/soil potentials may alternatively be output sequentially or upon command from the central monitoring facility, so that a pipe/soil potential may be obtained each day of the month from one of the 30 monitoring stations.
Still another feature of the invention is that the potential pipeline damage signal may be generated, e.g., by a geophone or a vibration detector, and the potential pipeline damage signal transmitted through the satellite communications module to a central monitoring facility. This feature of the invention provides significant safety for pipeline operations to minimize damage from accidents or terrorism.
Another feature of the invention is that the pipeline monitoring system is reliably able to monitor various pipeline operations, including the position of a valve, pressure and temperature of a fluid in the pipeline, monitoring the flow of fluid in the pipeline, and sensing one or more of CPR current, CPR voltage, and CPR meter readings. The pipeline system is also able to actuate devices at the monitoring station, e.g., activating a valve in response to instructions from the central monitoring facility,
Another feature of the invention is that the satellite communications module may be housed within a pipeline marker. A power source may be provided at each monitoring station to power the satellite communications module. In a subsea environment, a buoy is provided for supporting the satellite communications module, and transmission means are provided for transmitting a signal from the magnetic pig position detector from subsea to the satellite communications module.
According to the method of the invention, the passage of a magnetic pig is detected at each of the plurality of monitoring stations, and a signal output from the satellite communications module to the central monitoring facility indicates the passage of the pig. Pipe/soil potentials may be detected at a pre-programmed time and a voltage signal output through a satellite communications module. A damage alert module, when activated, will send a potential pipe damage signal to the central monitoring facility through the satellite communications module. The central monitoring facility may determine the speed of the magnetic pig moving through the pipeline, and estimate the arrival of the magnetic pig at another monitoring station. The central monitoring facility may generate command signals which are forwarded to a satellite communications module to operate each of the plurality of stations. If desired, a valve may be actuated in response to the detection of a passage of the magnetic pig.
A significant advantage of the present invention is that the cost of monitoring pipeline operations is significantly reduced, while also reducing the risk of accidents involved with pipeline personnel manually checking operations at monitoring stations.
A related advantage of the invention is that each of the components of the system is readily available, so a highly reliable and cost effective monitoring system is obtained.
These and further objects, features, and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a pipeline monitoring system according to the present invention.
FIG. 2 depicts a monitoring station positioned along the pipeline.
FIG. 3 illustrates both surface and subsea monitoring stations for a pipeline.
FIG. 4 is a block diagram of a monitoring station.
FIG. 5 is a block diagram of a pig signaling detector.
FIG. 6 is a block diagram of the check alarms section shown in FIG. 5 .
FIG. 7 is a block diagram of the pipeline pig check section shown in FIG. 6 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a pipeline monitoring system 10 according to a preferred embodiment of the invention, As shown in FIG. 3 , the pipeline P being monitored may include a plurality of pipe sections which are land based and underwater. The wide variety of environmental conditions which the pipeline may be exposed are known to those skilled in the art.
Positioned along the pipeline are plurality of monitoring stations 20 , with one such station being shown in FIG. 1 . The number of monitoring stations will depend on the length of the pipeline being monitored, and literally hundreds or thousands of monitoring stations may be monitored according to the system of the present invention. Each monitoring stations communicates with a central monitoring facility 50 , as discussed below.
Each monitoring station 20 serves as a data collection unit. A data transmission unit 22 , which may include an antenna and related communication circuitry such as that offered by Quake Global Communications, forwards the sensed data via satellite 60 to the central facility 50 . A magnetic pig position detector 24 is positioned close enough to the pipeline so that the magnetic field developed within the pipe by the pig is detected, thereby signaling pig position. The monitoring stations 20 may be installed when the pipeline is first laid or may be a retrofit to an existing pipeline. The monitoring stations may be conveniently positioned at pipeline warning signs typically positioned at road or waterway crossings.
Referring still to FIG. 1 , monitoring station 20 is adapted to receive receives signals from test leads 70 to determine the pipe/soil potentials for cathodic protection of the pipeline by the cathodic protection rectifiers (CPRs) 36 . The CPRs may also be used to transmit power to the monitoring station 20 which may then be used for monitoring various sensors 88 (see FIG. 4 ), including potential pipeline damage sensors, the CPR voltage, CPR current, CPR meter metering, leak detection, fluid flow rate through the pipeline, fluid temperature and pressure, valve position information, and pipeline temperatures.
An important pipeline operation to be monitored is a warning against foreign objects causing damage to a pipeline system. Others digging in the area of pipelines may damage the pipeline coating or cause indentations to the pipe wall. One of the sensors 88 is thus a potential pipeline damage detector or sensor, such as a geophone or a pipeline vibration sensor, which is coupled to the central monitoring station 50 to alert the pipeline operator of potential pipeline damage, which may be due to terrorist activities, by outputting a potential pipeline damage signal and the location of the event. As each analog signal from sensor 88 is received, the conditioner 92 converts the analog voltage to a digital signal. Command signals from the central monitoring facility may control a valve actuator for controlling operation of a valve at the monitoring station.
Each monitoring station 20 includes a power source 26 to power circuitry 28 . The power source 26 , which may be a battery 30 and/or solar collector 32 as shown in FIG. 2 , may also power the data transmission unit 22 . Connecting the power source 26 to the data transmission unit 22 also provides the operator at the central monitoring facility 50 with the information required to test or change the power source.
In another embodiment, the monitoring station 20 receives power from the voltage applied directly to the pipeline by the power source 34 of the cathodic protection rectifiers (CPRs) 36 . The CPRs 36 place a voltage, typically between −0.85 vdc and −1.2 vdc, at various locations along the pipeline to protect the pipeline from corrosion. Hence, the monitoring station 20 may be powered without any power source other than the voltage applied to the pipeline by the CPRs 36 . A monitoring station power source will typically operate at a voltage up to about 5 volts to about 24 volts. Quick disconnect determinations may be used for all power and communication components.
Referring to FIG. 2 , a typical monitoring station 20 may be positioned at a pipeline marker 70 , which extends upwardly from the ground and marks the location of the buried pipeline P. Battery packs 30 previously discussed may be positioned within the pipeline marker, and solar panel 32 may be secured at an upper end of the marker 70 . The antenna 22 extends upward from or may be contained within the pipeline marker, while the electronics package or circuitry 28 is housed within the pipeline marker. Although various functions may be monitored, the monitoring station 20 preferably includes at least a magnetic pig position detector 24 and test leads 70 for outputting signals indicative of the pipe/test voltage. As shown in FIG. 2 , the test leads include pipeline test lead 72 for obtaining a voltage signal of the pipeline P and ground test lead 74 , which may go to ground. A half-cell 75 , which may be buried in the ground, may be used to monitor the voltage differential between test lead 72 and ground lead 74 . The half-cell potential technique is an established and reliable method of monitoring pipeline voltage potential.
Referring now to FIG. 3 , the satellite communication system 60 is able to communicate with both land base monitoring stations 20 , 20 A, and 20 B as shown in FIG. 3 , each substantially similar to the system shown in FIG. 2 . When the pipeline is under water, the subsea sensor packages 80 provide signals of the pipeline operation, and transmit those signals by various means, including conventional wirelines 82 , to the monitoring station 20 , which in this case may be supported on a surface buoy 84 . The conductors 82 may be umbilical cables. When the pipeline is at an offshore location of greater than about 400 feet, high wire conductors are not preferable, and instead data may be acoustically transmitted from subsurface to the surface buoy.
Referring to FIG. 4 , the monitoring station includes a computer 68 and satellite communications module 86 for interfacing with antenna 22 . Sensors 88 , 88 A, 88 B provide pipeline monitoring signals to input/output module 90 . An analog to digital (A/D) converter 92 may connect module 90 to computer 68 . A digital to analog (D/A) converter 94 provides conversion from the computer to the sensors 88 , with the computer including firmware sufficient to control the various sensors 88 . A command signal from the central monitoring facility 50 to the communications module 86 may be converted by A/D converter 94 for activating actuator 96 which controls opening and closing of valve 98 . The pig position detector 24 and the test leads 70 are preferably used at every monitoring station, and similar A/D converters may be used between the computer 68 and both 24 and 70 .
Data transmission as shown in FIG. 1 is adaptable to a variety of communications systems by selecting a corresponding communications module 86 and antenna 22 . Each communications module 86 may include circuitry to interface the monitoring station 20 to the satellite communications system. The computer 68 is capable of entering a sleep mode to conserve power. The computer 68 may be awake when the magnetic pig 76 as shown in FIG. 2 passes by the monitoring station. The computer alternatively may be awakened in response to a signal from the control station 52 of the central monitoring facility 50 , or in response to a clock within the computer 68 . In either case, the triggering event causes the computer to perform selected tasks.
Although monitoring station 20 could theoretically communicate over a variety of wireless communications channels or mediums, including microwave radio, cellular radio and satellite communications, the preferred choice is the satellite system discussed below. Communication between antenna 22 and central monitoring facility 50 could use a microwave transmission/receiver to communicate with a microwave receiver/transmitter at the central monitoring facility 50 . Links of microwave stations may allow one station to communicate with the next microwave station. Undesirably, however, expensive microwave stations would be required at each monitoring station 20 . Alternatively, a cellular phone network could be developed between a cellular phone links at the monitoring stations to communicate with the central monitoring facility 50 . The use of a truck mounted radio link allows a technician to stay in communication with the pig even though the pig is a great distance removed. Cellular phone transmission often is poor, however, in remote areas where pipeline is often buried.
The preferred wireless communications system between antenna 22 and central monitoring facility 50 is the satellite communication system and service provided by Orbcomm, GlobalStar, or Iridium. Each of these satellite communications systems are Low Earth Orbiting Satellite Systems (LEOs). The satellite of an LEO has an orbital altitude range from 500 to 2000 km above the surface of the Earth. LEO satellites are conventionally part of constellations of satellites that achieve wide coverage of the Earth's surface with lower power requirements and shorter propagation delays that can be achieved with, e.g., geostationary orbit (GEO) satellites. Medium Earth Orbit (MEO) satellites have altitudes from 8000 to 20,000 km above the Earth, and GEOs have altitudes above 35,000 km above the Earth. LEO satellites may have equatorial or polar paths and both data and voice-and-data communications may be transmitted at preassigned frequency ranges. The LEO satellite system is able to transmit accurate and timely data from pipeline monitoring stations to any location in the world via the Internet.
Transmission from the monitoring station is linked to a satellite 60 , which in turn is linked to Earth station or central monitoring facility 50 , which includes a computer 52 , display screen 54 , and control station 56 . If desired, a fiber optic linkage may be used to transmit data from the satellite receiver 58 to the central monitoring facility 50 , or from the facility 50 to converter 62 , which may then transmit data via the Internet 64 to another database 66 . The approximate delay time between the initial data transmission and receipt of the data at the central monitoring facility should be approximately one minute or less, depending on the site. Those skilled in the art will appreciate that, while the control station 56 as shown in FIG. 1 is part of the central monitoring facility 50 , conventional communication systems may be positioned so that data may be output or displayed at various locations, and control may be from either the central monitoring facility 50 or any of various control stations to the monitoring stations 20 to control activities performed at each monitoring station in response to commands. Also, the monitoring station 20 preferably includes a computer 68 , which at minimum may include a time clock for outputting activity signals to the monitoring station. Also, programs within computer 68 may be programmed by command signals from the central monitoring facility 50 utilizing the satellite communication system 60 .
FIG. 5 is a flow chart of the magnetic sensing module 110 within the computer 68 , or if desired within the computer 52 of the central monitoring facility 50 . The magnetic sensing module 110 may receive eight analog inputs and one or more digital inputs. The analog inputs are converted to digital signals by A/D converter 92 (see FIG. 4 ). The computer 68 provides one or more digital outputs and one or more analog outputs that are converted by D/A converter 94 . When power is applied or when the computer is reset, the computer may begin operation by resetting or degaussing the sensor 24 , and performing similar operations on other sensors.
Next, the computer 68 takes readings over a period of time to locate maximum and minimum ambient noise to set data thresholds. The computer 68 then loops between steps to wait for an external event, such as the passage of the magnetic pig. Data is read from the magnetic sensing module 24 and the computer 68 determines if the data indicates passage of the magnetic pig. If the pig has not passed, then the computer 68 again samples data from the magnetic sensing module 24 . If the pig is detected, the computer proceeds to power up the communications module 86 in preparation for data transmission. The computer 68 may also sample data from a field interface unit which includes one or more sensors 88 , then transmits the data to the central monitoring facility 50 . The computer 68 also determines if another field interface unit is connected to the computer and, if so, to sample and transmit the data corresponding to the next field interface module. Once all the data is obtained, the computer 68 proceeds to power down the communications module to conserve power. Even though communications module is powered down, communications receiving circuitry remains powered up to receive data or command form the central monitoring facility 50 . After the data is communicated, the computer 68 proceeds to determine if the magnetic sensor 24 has become saturated. The output of the magnetic pig position detector 24 will drift or become offset if the sensor is again degaussed. If the output from sensor 24 is not saturated, the computer 68 waits for a command signal from facility 50 , or the passage of a pig, or a signal from the time clock within the computer. Signals from other sensors may be treated accordingly by the computer 68 .
As the magnetic pig passes each monitoring station 20 , an event is generated which causes information to be transferred to the central monitoring facility 50 . In addition to the information discussed above, a station identification and time of the event is passed to the central monitoring facility. As the pig passes a number of the monitoring stations 20 , the central monitoring facility 50 is able to use this information in determining the speed of the pig and the estimated time of arrival at the next station 20 .
Magnetic circuitry carried by the pig may be utilized to activate external equipment, such as valves, which may be sequenced during operations by the passage of the pig. Control in this manner may direct flow from the pipeline into holding tanks, e.g., when products carried by the pipeline do not need to be transported the entire pipeline length. Due to the configuration of the magnetic pig, the magnetic fields on board the pig may be arranged in a north-south configuration, or conversely in a south-north configuration, that is detectable by the magnetic pig position detector 24 . The different polar configurations may then be used to cause the opening and closing of the valves at certain points along the pipeline.
While various pipeline maintenance and operational data may be easily gathered by the sensors 88 of the monitoring station 20 , none is more important than cathodic protection tested with test leads 70 and potential pipeline damage sensors. Periodic checks of cathodic protection may be easily performed when a pig is sent through the pipeline. Monitoring stations 20 near CPRs 36 may thus relay rectifier voltages data to the central monitoring facility 50 to ensure that the pipe is protected by cathodic currents. Geophones, vibration sensors, or other pipeline damage sensors may forward a potential pipeline damage signal in substantially real time to the central monitoring facility. The same or other stations may take measurements to detect leakage and ensure proper settings. Fluid temperature, pressure and flow rates may be easily monitored and relayed to the facility 50 in a similar manner. Sensors may be provided for cathodic rectifier metering, alarm notification, external pipeline damage, flow rates, fluid temperatures and pressures, valve status, valve control, and pipeline pig monitoring. Various types of alarms may be provided, including system failure alarms, high and low limits.
Station identification may be easily correlated to a GPS location, and all triggering events may be monitored as a function of time. Monitoring according to the system of the present invention increases safety and allows the pipeline operator to better protect the pipeline asset. As one example, component failure may trigger an alarm which allows the pipeline operator to promptly correct problems while minimizing downtime. According to the method of the invention, a central monitoring facility computer may easily determine the speed of the pig as it is passing through the pipeline, and pig travel can be displayed in substantially real time to the operator, since the flow rate of the pig may be easily determined and the spacing between stations is known. Additionally, the monitoring station is able to control electronic settings of rectifiers at or near the monitoring station.
A magnetic sensing device, which serves as the pig position detector 24 , may be a single axis magnetoresistive circuit HMC1O1 made by Honeywell, connected to the inputs of the amplifier. Other magnetic sensing means, such as inductive coils, flux gates and hall-effect sensors may be used. A reset circuit responsive to the computer 68 may be used to eliminate signal degradation of the magnetic sensing device caused by continuous exposure to magnetic fields.
The magnetic sensing device 24 may be calibrated to a predetermined reference point by computer 68 . An analog feedback signal may be provided from the computer to compensate for background magnetic fields, such as those created by the earth and overhead electrical lines.
A low operational cost pipeline monitoring system is thus disclosed which may utilize a magnetic pig to automate the collection of data from a number of sources and transmit the data via a satellite communications systems to the central monitoring facility. A pipeline monitoring system as disclosed herein may also be used for transmitting pipe/soil potentials from a plurality of monitoring stations to the central monitoring facility. Additionally, a satellite transmission system may be used for monitoring pipeline damage, and signals from a geophone, vibration sensor, or other pipeline damage sensor may be transmitted to the central monitoring facility upon the generation of a potential pipeline damage signal.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, materials, components, circuit elements, wiring connections and contacts, as well as in the details of the illustrated circuitry and construction method of operation may be made without departing from the spirit of the invention. | A pipeline monitoring system includes a series of monitoring stations ( 20 ), each having a computer ( 68 ), magnetic pig position detector ( 24 ), one or more input/output modules ( 90 ) and communications module ( 86 ). The communications module is operable to transmit data over a communications network from a remotely located monitoring stations ( 20 ) to a central monitoring facility ( 50 ). Commands transmitted from the central monitoring facility or events generated by the passage of a magnetic pig cause the monitoring station to automatically perform selected processes. The central monitoring facility may also use preprogrammed commands to effect reporting at pre-selected times and dates, and may forward pipe/soil potentials or pipeline damage signals to the central monitoring facility. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/277,624, filed on Sep. 28, 2009 by the same inventor, the contents of which are incorporated by reference as though fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to providing heat and deposition gas control during the deposition of material on a wafer or substrate used for example in the production of High Brightness Light Emitting Diodes (LEDs semiconductor devices), solar cells and other semiconductor devices.
[0004] 2. Description of the Related Art
[0005] A typical semiconductor device layer(s) may be elements or compounds such as GaN, InN, AlN or Si deposited on wafers using a deposition system. These layers of elements and or compounds are essential to technologies such as modern microelectronics, solar cells and LED devices.
[0006] It is desirable to increase the growth rate of the semiconductor material during the formation of the semiconductor layer so that more electronic devices and circuits can be formed in a given amount of time. It is desirable to control the uniformity of the semiconductor material allowing a number of identical electronic devices and circuits to be formed. The uniformity of the semiconductor material refers to the uniformity of its composition and the thickness of the layer. It is sometimes desirable to deposit semiconductor material that has the same composition from one location to another on the wafer. For example, it is known that gallium rich volumes are often undesirably formed when depositing gallium nitride. These gallium rich volumes can undesirably degrade the performance of an electronic device formed therewith.
[0007] A heater assembly is often used to heat the wafer in the presence of reactant gases that decompose and or combine chemically depositing a layer of semiconductor materials on wafers. There are many different types of heater assemblies that can be used to heat the wafer, such as those disclosed in U.S. Pat. Nos. 6,331,212 and 6,774,060. Some heater assemblies provide heat through induction heating, and others provide heat through resistance heating. Some heater assemblies, such as the one disclosed in U.S. Pat. No. 4,081,313, provide heat through infrared lamps.
[0008] However, there are several problems with deposition systems. One problem is the difficulty in uniformly heating the wafer(s) so that the semiconductor layers are deposited uniformly with a uniform composition. Another problem is controlling the process gases in order that the heated wafer(s) sees a composition of process gases that decompose and or combine so that the semiconductor layers are deposited uniformly with a uniform composition on the wafer. There is a crucial need in today's process requirements for epitaxial CVD, for systems with heating methods that provide improved wafer temperature control, uniformity and repeatability and reactant gas control and distribution over the wafer(s) so that semiconductor layers are deposited with improved film uniformity, higher throughput and a much reduced cost per wafer.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is directed to an apparatus for the chemical vapor deposition of semiconductor films specifically related to a novel heater assembly and gas introduction schemes. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 a is a top view of one embodiment of a heater assembly 100
[0011] FIG. 1 b is a side view of one embodiment of a heater assembly 100 a along cut line 1 b - 1 b of FIG. 1 a
[0012] FIG. 1 c is a side view of an embodiment of a heater assembly 100 a along cut line 1 b - 1 b of FIG. 1 a
[0013] FIG. 1 d is a side view of another embodiment of a heater assembly 100 b along cut line 1 b - 1 b of FIG. 1 a
[0014] FIG. 1 e is a representative heat/temperature profile of heater assembly 100 of FIG. 1 b
[0015] FIG. 1 f is a representative heat/temperature profile along cut line heater assembly 100 a of FIG. 1 c
[0016] FIG. 1 g is a representative heat/temperature profile of a heater assembly
[0017] FIG. 2 a is a top view of one embodiment of heater plate 110
[0018] FIG. 2 b is a perspective view of heater plate 110
[0019] FIG. 2 c is a cut-away side view of heater plate 110
[0020] FIG. 3 a is a top view of inner segmented heater sub-assembly 120
[0021] FIG. 3 b is a perspective view of segmented heater sub-assembly 120
[0022] FIG. 3 c is side view of segmented heater sub-assembly 120
[0023] FIG. 3 d is a side view of inner segmented heater sub-assembly 120 in a region 129 of FIG. 3 c
[0024] FIG. 3 e is a side view of another embodiment of inner segmented heater sub-assembly 120 in region 129
[0025] FIG. 3 f is a perspective view of heater sub-assembly 120 in region 129 ,
[0026] FIG. 4 a is a top view of one embodiment of intermediate segmented heater sub-assembly 140
[0027] FIG. 4 b is a perspective view of intermediate segmented heater sub-assembly 140
[0028] FIG. 4 c is a cut-away side view of intermediate segmented heater sub-assembly 140 in region 149
[0029] FIG. 4 d is a side view of intermediate segmented heater sub-assembly 140 in region 149
[0030] FIG. 4 e is a side view of another embodiment of intermediate segmented heater sub-assembly 140 in region 149
[0031] FIG. 4 f is a perspective view of intermediate segmented heater sub-assembly 140 in region 149 ,
[0032] FIG. 5 a is a top view of one embodiment of outer segmented heater sub-assembly 160
[0033] FIG. 5 b is a perspective view of outer segmented heater sub-assembly 160
[0034] FIG. 5 c is a cut-away side view of outer segmented heater sub-assembly 160
[0035] FIG. 5 d is a side view of outer segmented heater sub-assembly 160 in a region 169
[0036] FIG. 5 e is a side view of another embodiment of outer segmented heater sub-assembly 160
[0037] FIG. 6 is a top view of one embodiment of a heater assembly 100 a
[0038] FIG. 7 is a top view of one embodiment of coiled heater 110
[0039] FIG. 8 a is a perspective view of a heater coil 170
[0040] FIG. 8 b is a top views of a heater coil 170
[0041] FIGS. 9 a and 9 b are perspective and top views, respectively, of another embodiment of a heater coil, denoted as heater coil 170 a
[0042] FIGS. 10 a and 10 b are top and side views, respectively, of one embodiment of a coiled inner segmented heater assembly 181 .
[0043] FIG. 11 a and 11 b are top and side views, respectively, of one embodiment of a coiled intermediate segmented heater assembly 182
[0044] FIGS. 12 a and 12 b are top and side views, respectively, of one embodiment of a coiled outer segmented heater assembly 100 .
[0045] FIG. 13 a is a top view of one embodiment of a heater assembly 100 b
[0046] FIG. 13 b is a top view of one embodiment of a heater assembly 100 c
[0047] FIG. 13 c is a top view of one embodiment of a heater assembly 100 d
[0048] FIG. 13 d is a top view of one embodiment of a heater assembly 100 e
[0049] FIG. 13 e is a top view of one embodiment of a heater assembly 100 f
[0050] FIG. 14 a is a cut-away side view of deposition system 200
[0051] FIG. 14 b is cross sectional view of the interior of the deposition system 200
[0052] FIG. 14 c is cross sectional plan view along cut line 14 b - 14 b of FIG. 14 b
[0053] FIG. 14 d is a cross section plan view of heater array 100 along cut line 14 b 1 - 14 b 1 of FIG. 14 b
[0054] FIG. 14 e is an expanded view of the upper and lower heater assemblies 100 of deposition system 200
[0055] FIG. 14 f is a thermal comparison of the embodiments herein versus two prior art technologies
[0056] FIG. 15 a is a side cross-sectional view of reactor chamber and gas system of deposition system 200 a.
[0057] FIG. 15 b is an expanded cross sectional side view of the gas injection scheme as defined by region 219 of FIG. 14 b.
[0058] FIG. 15 c is a pictorial view of the one of the upstream gas inlet ports 226 and one of the downstream gas inlet ports 225 .
[0059] FIG. 15 d is an expanded view along cut line 15 d - 15 d of FIG. 15 c of the downstream gas inlet port 229
[0060] FIG. 15 e is a plan view of the upstream gas injection embodiment of deposition system 200
[0061] FIG. 15 f is a plan view of the downstream gas inject embodiment of deposition system 200
[0062] FIG. 16 a is a cross sectional view of a vertical gas inject scheme of deposition system 200 b
[0063] FIG. 16 b is an exploded cross sectional view of a vertical gas inject scheme of deposition system 200 b
[0064] FIG. 16 c is a plan view of the upper plate of process chamber 204 c a vertical gas inject scheme
[0065] FIG. 15 d is comparison of the depletion profile of prior art and the invention
DETAILED DESCRIPTION OF THE INVENTION
[0066] Heater assemblies disclosed herein provide heat during the deposition of material on a wafer. The material is deposited using a deposition system, such as a CVD, MBE, HVPE or MOCVD system. The material deposited on the wafer can be of many different types, such as semiconductor material. Electronic devices and circuitry are often formed on the wafer, wherein the electronic device and circuitry utilize the material deposited.
[0067] The heater assemblies disclosed herein uniformly heat the wafer so that the material is deposited uniformly. Further, the material is deposited on the wafer at a faster rate so that more electronic devices and circuits can be formed in a given amount of time.
[0068] The heater assemblies disclosed herein heat the wafer uniformly so that the material being deposited has a more uniform composition. In this way, the material deposited on the wafer is driven to have the same composition at different locations of the wafer. This is useful so that the electronic devices and circuits at different locations of the wafer are driven to be identical.
[0069] The gas control, injection and distribution embodiments disclosed herein distribute process gases over wafer(s) more uniformly and with more control. The gases are distributed over areas of the wafer(s) being heated by the heater assemblies are controlled together so that material is deposited on the wafer more uniformly with a more uniform composition and at a faster rate.
[0070] FIG. 1 a is a top view of one embodiment of a heater assembly 100 , and FIG. 1 b is a cut-away side view of heater assembly 100 taken along a cut-line 1 b - 1 b of FIG. 1 a . In this embodiment, heater assembly 100 includes a heater plate sub-assembly 110 , and an inner segmented heater sub-assembly 120 spaced from heater plate sub-assembly 110 by an inner annular gap 105 . Inner annular gap 105 is dimensioned to prohibit the ability of current to flow between heater assemblies 110 and 120 . It is desirable to prohibit the ability of current to flow between heater assemblies 110 and 120 so that different adjustable power signals can be provided to each. The center 103 of heater assembly 100 may be coincident with the center of heater plate sub-assembly 110 .
[0071] It is desirable to provide different adjustable power signals to heater assemblies 110 and 120 so they provide different adjustable amounts of heat. The amount of heat provided by heater assemblies 110 and 120 is adjustable in response to adjusting the corresponding adjustable power signals. It is desirable for heater assemblies 110 and 120 to provide different adjustable amounts of heat so they are thermally decoupled from each other. The thermal coupling between heater assemblies 110 and 120 is adjustable in response to adjusting the corresponding adjustable power signal. It is desirable to thermally decouple heater assemblies 110 and 120 so the uniformity of the heat provided by heater assembly 100 can be better controlled. The uniformity of the heat provided by heater assembly 100 is adjustable in response to adjusting the corresponding adjustable power signal provided to heater assemblies 110 and 120 .
[0072] In this embodiment, heater assembly 100 includes an intermediate segmented heater sub-assembly 140 consisting of intermediate heater segment 140 a and 140 b , spaced from inner segmented heater sub-assembly 120 by an intermediate annular gap 106 . Intermediate annular gap 106 is dimensioned to inhibit the ability of current to flow between heater assemblies 120 and 140 . It is desirable to inhibit the ability of current to flow between heater assemblies 110 and 120 so that different adjustable power signals can be provided to them.
[0073] It is desirable to provide different adjustable power signals to heater assemblies 120 and 140 so they provide different adjustable amounts of heat. The amount of heat provided by heater assemblies 120 and 140 is adjustable in response to adjusting the corresponding adjustable power signals. It is desirable for heater assemblies 120 and 140 to provide different adjustable amounts of heat so they are thermally decoupled from each other. The thermal coupling between heater assemblies 120 and 140 is adjustable in response to adjusting the corresponding adjustable power signal. It is desirable to thermally decouple heater assemblies 120 and 140 so the uniformity of the heat provided by heater assembly 100 can be better controlled. The uniformity of the heat provided by heater assembly 100 is adjustable in response to adjusting the corresponding adjustable power signal provided to heater assemblies 120 and 140 .
[0074] In this embodiment, heater assembly 100 includes an outer segmented heater sub-assembly 160 consisting of outer heater segment 160 a , 160 b , 160 c and 160 d spaced from intermediate segmented heater sub-assembly 140 by an outer annular gap 107 . Outer annular gap 107 is dimensioned to inhibit the ability of current to flow between heater assemblies 140 and 160 . It is desirable to prohibit the ability of current to flow between heater assemblies 140 and 160 so that different adjustable power signals can be provided to them.
[0075] It is desirable to provide different adjustable power signals to heater sub-assemblies 140 and 160 so they provide different adjustable amounts of heat. The amount of heat provided by heater sub-assemblies 140 and 160 is adjustable in response to adjusting the corresponding adjustable power signals. It is desirable for heater sub-assemblies 140 and 160 to provide different adjustable amounts of heat so they are thermally decoupled from each other. The thermal coupling between heater sub-assemblies 140 and 160 is adjustable in response to adjusting the corresponding adjustable power signal. It is desirable to thermally decouple heater sub-assemblies 140 and 160 so the uniformity of the heat provided by heater assembly 100 can be better controlled. The uniformity of the heat provided by heater assembly 100 is adjustable in response to adjusting the corresponding adjustable power signal provided to heater sub-assemblies 140 and 160 .
[0076] It should be noted that inner gap 105 , intermediate gap 106 and outer gap 107 are annular gaps because they extend annularly around heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 and intermediate segmented heater sub-assembly 140 , respectively.
[0077] In operation, different power signals are provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater sub-assembly 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 . Heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 provide heat in response to receiving the corresponding power signal.
[0078] In one mode of operation, adjustable power signals are provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 , wherein the adjustable power signals are adjusted to regulate the amount of heat provided by heater assembly 100 .
[0079] For example, in one embodiment, the amount of heat provided by heater assembly 100 is adjusted in response to adjusting the phases of the power signals. In one particular embodiment, an alternating current power signal is provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 . The phases of the alternating current power signals are adjusted relative to each other to adjust the amount of heat provided by heater assembly 100 . In this way, the amount of heat provided by heater assembly 100 is regulated in response to adjusting the phases of the power signals.
[0080] In another embodiment, the amount of heat provided by heater assembly 100 is adjusted in response to adjusting the amplitudes of the power signals. In one particular embodiment, an alternating current power signal is provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b and outer heater segment 160 a , 160 b , 160 c and 160 d heater sub-assembly 160 . In this embodiment, the alternating current power signals can have different phases. In one embodiment, the alternating current power signals are out of phase by 120 degrees. Alternating current power signals out of phase by 120 degrees are often used in three-phase systems, such as a three-phase motor. In this way, the amount of heat provided by heater assembly 100 is adjusted in response to adjusting the amplitudes of the power signals.
[0081] In one mode of operation, adjustable power signals are provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 , wherein the adjustable power signals are adjusted to adjust the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 .
[0082] For example, in one embodiment, the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 is adjusted in response to adjusting the phases of the power signals. In one particular embodiment, a direct current power signal is provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 . The amplitude of the direct current power signals is adjusted relative to each other to adjust the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 . In this way, the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 is adjusted in response to adjusting the amplitude of the power signals.
[0083] In another embodiment, the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 is adjusted in response to adjusting the amplitudes of the power signals. In one particular embodiment, a direct current power signal is provided to heater plate sub-assembly 110 , and alternating current power signals are provided to inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 . In this embodiment, the alternating current power signals can have many different phases. In one embodiment, the alternating current power signals are out of phase by 120 degrees. Alternating current power signals out of phase by 120 degrees are often used in three-phase high power systems, such as a three-phase motor. In this way, the thermal coupling between heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 is adjusted in response to adjusting the amplitudes of the power signals.
[0084] In one mode of operation, adjustable power signals are provided to heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 , wherein the adjustable power signals are adjusted to adjust the uniformity of the heat provided by heater assembly 100 .
[0085] In one particular embodiment, a direct current power signal is provided to heater plate sub-assembly 110 , and alternating current power signals are provided to inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 . The phases of the alternating current power signals are adjusted relative to each other to adjust the uniformity of the heat provided by heater assembly 100 . In this way, the uniformity of the heat provided by heater assembly 100 is regulated in response to adjusting the phases of power signals.
[0086] In another embodiment, the uniformity of the heat provided by heater assembly 100 is adjusted in response to adjusting the amplitudes of the power signals. In one particular embodiment, a direct current power signal is provided to heater plate sub-assembly 110 , and alternating current power signals are provided to inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 . In this embodiment, the alternating current power signals can have many different phases. In one embodiment, the alternating current power signals are out of phase by 120 degrees. Alternating current power signals out of phase by 120 degrees are often used in high power electrical systems, such as a three-phase motor. In this way, the uniformity of the heat provided by heater assembly 100 is adjusted in response to adjusting the amplitudes of the power signals.
[0087] It should also be noted that heater assembly 100 , as shown in FIG. 1 b , has a uniform thickness. Heater assembly 100 of FIG. 1 b has a uniform thickness because the thicknesses of heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 are the same thickness values between inner gap 105 and the outer periphery of outer segmented heater sub-assembly 160 .
[0088] The thicknesses of heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate segmented heater sub-assembly 140 and outer segmented heater sub-assembly 160 are chosen to provide a desired resistance. The resistance of heater plate sub-assembly 110 increases and decreases as its thickness decreases and increases, respectively. The resistance of inner segmented heater sub-assembly 120 increases and decreases as its thickness decreases and increases, respectively. The resistance of intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 increases and decreases as its thickness decreases and increases, respectively. The resistance outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 increases and decreases as its thickness decreases and increases, respectively. It should be noted that, for a given amount of power, the amount of heat provided by a sub-assembly increases and decreases as its resistance increases and decreases, respectively.
[0089] FIG. 1 c is a side view of a heater assembly 100 a having a non-uniform thickness. Heater assembly 100 a has a non-uniform thickness because it includes a sub-assembly having a non-uniform thickness. In this embodiment, heater assembly 100 a has a non-uniform thickness because the thicknesses of inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 have thickness values that vary between inner gap 105 and the outer periphery of outer segmented heater sub-assembly 160 . In this way, the intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 each have a non-uniform thickness.
[0090] The thicknesses of heater plate sub-assembly 110 , inner segmented heater sub-assembly 120 , intermediate heater segment 140 a and 140 b of intermediate segmented heater sub-assembly 140 and outer heater segment 160 a , 160 b , 160 c and 160 d of outer segmented heater sub-assembly 160 are chosen to provide a desired resistance. As mentioned above, the resistance of heater plate sub-assembly 110 increases and decreases as its thickness decreases and increases, respectively.
[0091] The resistance of inner segmented heater sub-assembly 120 increases and decreases as its thickness decreases and increases, respectively. In this embodiment, inner segmented heater sub-assembly 120 is thicker proximate to inner gap 105 and thinner proximate to intermediate gap 106 . Inner segmented heater sub-assembly 120 is less resistive proximate to inner gap 105 because it is thicker proximate to inner gap 105 . Further, inner segmented heater sub-assembly 120 is more resistive proximate to intermediate gap 106 because it is thinner proximate to intermediate gap 106 . It is desirable to have inner segmented heater sub-assembly 120 less resistive proximate to inner gap 105 and more resistive proximate to intermediate gap 106 so that inner segmented heater sub-assembly 120 provides less heat proximate to inner gap 105 and more heat proximate to intermediate gap 106 . It is desirable to have inner segmented heater sub-assembly 120 provide less heat proximate to inner gap 105 and more heat proximate to intermediate gap 106 because inner gap 105 is closer to center 103 than intermediate gap 106 . In this way, inner segmented heater sub-assembly 120 provides a more uniform amount of heat.
[0092] The resistance of intermediate segmented heater sub-assembly 140 increases and decreases as its thickness decreases and increases, respectively. The resistance of intermediate segmented heater sub-assembly 140 increases and decreases as its thickness decreases and increases, respectively. In this embodiment, intermediate segmented heater sub-assembly 140 is thicker proximate to intermediate gap 106 and thinner proximate to outer gap 107 . Intermediate segmented heater sub-assembly 140 is less resistive proximate to intermediate gap 106 because it is thicker proximate to intermediate gap 106 . Further, intermediate segmented heater sub-assembly 140 is more resistive proximate to outer gap 107 because it is thinner proximate to outer gap 107 . It is desirable to have intermediate segmented heater sub-assembly 140 less resistive proximate to intermediate gap 106 and more resistive proximate to outer gap 107 so that intermediate segmented heater sub-assembly 140 provides less heat proximate to intermediate gap 106 and more heat proximate to outer gap 107 . It is desirable to have intermediate segmented heater sub-assembly 140 provide less heat proximate to intermediate gap 106 and more heat proximate to outer gap 107 because intermediate gap 106 is closer to center 103 than outer gap 107 . In this way, intermediate segmented heater sub-assembly 140 provides a more uniform amount of heat.
[0093] The resistance of outer segmented heater sub-assembly 160 increases and decreases as its thickness decreases and increases, respectively. The resistance of outer segmented heater sub-assembly 160 increases and decreases as its thickness decreases and increases, respectively. In this embodiment, outer segmented heater sub-assembly 160 is thicker proximate to outer gap 107 and thinner proximate to the outer periphery of heater assembly 100 . Outer segmented heater sub-assembly 160 is less resistive proximate to outer gap 107 because it is thicker proximate to outer gap 107 . Further, outer segmented heater sub-assembly 160 is more resistive proximate to the outer periphery of heater assembly 100 because it is thinner proximate to the outer periphery of heater assembly 100 . It is desirable to have outer segmented heater sub-assembly 160 less resistive proximate to outer gap 107 and more resistive proximate to the outer periphery of heater assembly 100 so that outer segmented heater sub-assembly 160 provides less heat proximate to outer gap 107 and more heat proximate to the outer periphery of heater assembly 100 . It is desirable to have outer segmented heater sub-assembly 160 provide less heat proximate to outer gap 107 and more heat proximate to the outer periphery of heater assembly 100 because outer gap 107 is closer to center 103 than the outer periphery of heater assembly 100 . In this way, outer segmented heater sub-assembly 160 provides a more uniform amount of heat.
[0094] FIG. 1 d is a side view of a heater assembly 100 b which includes a segmented heater assembly with a uniform thickness and another segmented heater assembly with a non-uniform thickness. For example, in this embodiment, heater assembly 100 b includes heater plate 110 and intermediate segmented heater sub-assembly 140 , as shown in FIG. 1 a . In this embodiment, heater assembly 100 b includes intermediate segmented heater sub-assembly 140 , wherein intermediate segmented heater sub-assembly 140 has a non-uniform thickness. Intermediate segmented heater sub-assembly 140 is positioned between heater plate 110 and intermediate segmented heater sub-assembly 140 . Further, heater assembly 100 b includes outer segmented heater sub-assembly 160 , wherein outer segmented heater sub-assembly 160 has a non-uniform thickness. Outer segmented heater sub-assembly 160 is positioned around intermediate segmented heater sub-assembly 140 .
[0095] It should be noted that any of the heater assemblies discussed herein can include many different combinations of uniform and non-uniform segmented heater assemblies, but only a few are shown for simplicity and ease of discussion. The particular combination of uniform and non-uniform segmented heater assemblies depends on many different factors, such as the desired heat profile of the heater assembly. As mentioned above, the uniformity of a semiconductor layer deposited on a wafer increases and decreases as the heat profile of the heater assembly becomes more and less uniform.
[0096] FIG. 1 e is a representative heat/temperature profile along cut line of FIG. 1 a of heater assembly 100 with the heater cross sectional embodiment of FIG. 1 b showing the variance temperature measured diametrically across heater 160 d , 140 b , 120 , 110 , 120 , 140 a and 160 b.
[0097] FIG. 1 f is a representative heat/temperature profile along cut line of FIG. 1 a of heater assembly 100 a with the heater cross sectional embodiment of FIG. 1 c showing an improved temperature variance measured diametrically across heater 160 d , 140 b , 120 , 110 , 120 , 140 a and 160 b as compared to FIG. 1 e.
[0098] FIG. 1 g is a representative heat/temperature profile along cut line of FIG. 1 a of heater assembly 100 a with the heater cross sectional embodiment optimally designed as discussed below showing an improved temperature variance measured diametrically across heater 160 d , 140 b , 120 , 110 , 120 , 140 a and 160 b as compared to FIG. 1 f.
[0099] FIG. 2 a is a top view of one embodiment of heater plate 110 , FIG. 2 b is a perspective view of heater plate 110 and FIG. 2 c is a cut-away side view of heater plate 110 taken along a cut-line 2 c - 2 c of FIG. 2 a . In this embodiment, heater plate sub-assembly 110 includes opposed surfaces 115 a and 115 b , and is bounded by an outer peripheral surface 113 . Outer peripheral surface 113 extends adjacent to inner gap 105 ( FIG. 1 a ), and faces inner segmented heater sub-assembly 120 .
[0100] In this embodiment, heater plate sub-assembly 110 includes contacts 112 a and 112 b , which are spaced apart from each other. Heater plate sub-assembly 110 flows heat through opposed surfaces 115 a and 115 b in response to a potential difference V 0 established between contacts 112 a and 112 b . Heater plate sub-assembly 110 flows heat through opposed surfaces 115 a and 115 b in response to a current flowing between contacts 112 a and 112 b in response to the potential difference established between contacts 112 a and 112 b from the adjustable signal applied to these contacts as previously discussed.
[0101] FIG. 3 a is a top view of one embodiment of inner segmented heater sub-assembly 120 , FIG. 3 b is a perspective view of inner segmented heater sub-assembly 120 and FIG. 3 c is a cut-away side view of inner segmented heater sub-assembly 120 taken along a cut-line 3 c - 3 c of FIG. 3 a . In this embodiment, inner segmented heater sub-assembly 120 includes opposed surfaces 125 a and 125 b , and is bounded by an outer peripheral surface 123 and inner peripheral surface 124 . Opposed surfaces 125 a and 125 b are gapped surfaces because inner radial slot 126 extends therethrough. Radial slot 126 is dimensioned to inhibit the ability of current to flow between surfaces 128 a and 128 b.
[0102] Outer peripheral surface 123 extends adjacent to intermediate gap 106 ( FIGS. 1 a and 1 b ), and faces intermediate segmented heater sub-assembly 140 . Inner peripheral surface 124 extends adjacent to inner gap 105 ( FIGS. 1 a and 1 b ), and faces inner segmented heater sub-assembly 110 . In this way, inner gap 105 is bounded by outer peripheral surface 113 and inner peripheral surface 124 . Inner gap 105 is dimensioned to inhibit the ability of current to flow between heater assemblies 110 and 120 . Inner segmented heater sub-assembly 120 includes a central opening 121 sized and shaped to receive heater plate sub-assembly 110 ( FIGS. 1 a and 1 b ).
[0103] In this embodiment, inner segmented heater sub-assembly 120 includes contacts 122 a and 122 b , which are spaced apart from each other by a radial gap 126 . Inner segmented heater sub-assembly 120 flows heat through opposed surfaces 125 a and 125 b in response to a potential difference established between contacts 122 a and 122 b . Inner segmented heater sub-assembly 120 flows heat through opposed surfaces 125 a and 125 b in response to a current flowing between contacts 122 a and 122 b . It should be noted that the current flows between contacts 122 a and 122 b in response to the potential difference established between contacts 122 a and 122 b by the adjustable signal applied as discussed above.
[0104] Radial gap 126 is a radial gap because it extends along a radial line 104 , which extends radially outward from a center 103 of heater plate sub-assembly 110 ( FIG. 1 a ). It should be noted that, in this embodiment, center 103 of heater plate sub-assembly 110 corresponds to a center of heater assembly 100 . In this embodiment, radial gap 126 is bounded by opposed radial gap surfaces 127 and 128 . Radial gap surfaces 127 and 128 extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 123 and inner peripheral surface 124 .
[0105] FIG. 3 d is a side view of inner segmented heater sub-assembly 120 in a region 129 of FIG. 3 c . As shown in FIG. 3 d , inner segmented heater sub-assembly 120 has inner and outer thicknesses t 1 and t 2 . Inner thickness t 1 is the thickness of inner segmented heater sub-assembly 120 proximate to inner peripheral surface 124 and outer thickness t 2 is the thickness of inner segmented heater sub-assembly 120 proximate to outer peripheral surface 123 .
[0106] Inner segmented heater sub-assembly 120 has a uniform thickness when thicknesses t 1 and t 2 are the same, and inner segmented heater sub-assembly 120 has thickness t 1 between outer peripheral surface 123 and inner peripheral surface 124 . Inner segmented heater sub-assembly 120 has a uniform thickness when thicknesses t 1 and t 2 are the same, and inner segmented heater sub-assembly 120 has thickness t 2 between outer peripheral surface 123 and inner peripheral surface 124 .
[0107] Inner segmented heater sub-assembly 120 has a uniform thickness when thicknesses t 1 and t 2 are the same, and opposed surfaces 125 a and 125 d are spaced apart from each other by thickness t 1 . Inner segmented heater sub-assembly 120 has a uniform thickness when thicknesses t 1 and t 2 are the same, and opposed surfaces 125 a and 125 d are spaced apart from each other by thickness t 2 . In the embodiment in which inner segmented heater sub-assembly 120 has a uniform thickness, opposed surfaces 125 a and 125 b are parallel to each other.
[0108] FIG. 3 e is a side view of another embodiment of inner segmented heater sub-assembly 120 in region 129 , and FIG. 3 f is a corresponding perspective view of the embodiment of FIG. 3 e , wherein inner segmented heater sub-assembly 120 has a non-uniform thickness. Inner segmented heater sub-assembly 120 of FIGS. 3 e and 3 f correspond to inner segmented heater sub-assembly 120 of FIG. 1 c . In FIGS. 3 d and 3 e , inner segmented heater sub-assembly 120 has a non-uniform thickness because thicknesses t 1 and t 2 are unequal, and the thickness of inner segmented heater sub-assembly 120 is non-uniform between inner peripheral surface 124 and outer peripheral surface 123 . In this particular embodiment, thickness t 1 is greater than thickness t 2 . It should be noted, however, that thickness t 2 is greater than thickness t 1 in other embodiments. In the embodiment in which inner segmented heater sub-assembly 120 has a non-uniform thickness, opposed surfaces 125 a and 125 b are not parallel to each other.
[0109] Surfaces 125 a and 125 b can have many different shapes. For example, in FIG. 3 d , surfaces 125 a and 125 b are flat surfaces which extend parallel to each other because t 1 and t 2 are equal. In FIGS. 3 e and 3 f , surfaces 125 a and 125 b are flat surfaces which do not extend parallel to each other because t 1 and t 2 are not equal. In some embodiments, surfaces 125 a and 125 c are flat surfaces and, in other embodiments, surfaces 125 a and 125 c are curved surfaces or combinations thereof. In some embodiments, surfaces 125 a and 125 c are curved so they are concave and, in other embodiments, surfaces 125 a and 125 c are curved so they are convex.
[0110] FIG. 4 a is a top view of one embodiment of intermediate segmented heater sub-assembly 140 , FIG. 4 b is a perspective view of intermediate segmented heater sub-assembly 140 and FIG. 4 c is a cut-away side view of intermediate segmented heater sub-assembly 140 taken along a cut-line 4 c - 4 c of FIG. 4 a . In this embodiment, intermediate segmented heater sub-assembly 140 includes intermediate heater segments 140 a and 140 b . Intermediate heater segments 140 a and 140 b include opposed surfaces 145 a and 145 b , and are bounded by an outer peripheral surface 143 and inner peripheral surface 144 . Outer peripheral surface 143 extends adjacent to outer gap 107 ( FIGS. 1 a and 1 b ), and faces outer segmented heater sub-assembly 160 . Inner peripheral surface 144 extends adjacent to intermediate gap 106 ( FIGS. 1 a and 1 b ), and faces inner segmented heater sub-assembly 120 . In this way, intermediate gap 106 is bounded by outer peripheral surface 123 and inner peripheral surface 144 . Intermediate gap 106 is dimensioned to inhibit the ability of current to flow between heater assemblies 120 and 140 . Intermediate segmented heater sub-assembly 140 includes a central opening 141 sized and shaped to receive inner segmented heater sub-assembly 120 ( FIGS. 1 a and 1 b ).
[0111] In this embodiment, intermediate segmented heater sub-assembly 140 includes contacts 142 a and 142 b , which are carried by intermediate heater segment 140 b . In this embodiment, intermediate segmented heater sub-assembly 140 includes contacts 142 c and 142 d , which are carried by intermediate heater segment 140 a . In this embodiment, contacts 142 b and 142 c are spaced apart from each other by a radial gap 146 a . In this embodiment, contacts 142 a and 142 d are spaced apart from each other by a radial gap 146 b . Intermediate heater segments 140 a and 140 b are spaced apart from each other by radial gaps 146 a and 146 b.
[0112] Radial gap 146 a is a radial gap because it extends along radial line 104 , which extends radially outward from center 103 of heater plate sub-assembly 110 ( FIG. 1 a ). In this embodiment, radial gap 146 a is bounded by opposed radial gap surfaces 147 a and 148 a . Radial gap surfaces 147 a and 148 a extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 143 and inner peripheral surface 144 .
[0113] Radial gap 146 b is a radial gap because it extends along a radial line, which extends radially outward from center 103 of heater plate sub-assembly 110 . In this embodiment, radial gap 146 b is bounded by opposed radial gap surfaces 147 b and 148 b . Radial gap surfaces 147 b and 148 b extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 143 and inner peripheral surface 144 . Radial slot 146 a is dimensioned to inhibit the ability of current to flow between surfaces 148 a and 148 d . Radial slot 145 b is dimensioned to inhibit the ability of current to flow between surfaces 148 b and 148 c.
[0114] Intermediate segmented heater sub-assembly 140 flows heat through opposed surfaces 145 a and 145 b in response to a potential difference V 2 and V 3 established between contacts 142 a and 142 b and between contracts 142 c and 142 d respectively. It should be noted that the current flows between contacts 142 a and 142 b in response to the potential difference established between contacts 142 a and 142 b and between contacts 142 c and 142 d in response to the potential difference established between contacts 142 c and 142 d by the adjustable signals applied to the contacts as discussed above.
[0115] FIG. 4 d is a side view of intermediate segmented heater sub-assembly 140 in a region 149 of FIG. 4 c . As shown in FIG. 4 d , intermediate segmented heater sub-assembly 140 has inner and outer thicknesses t 3 and t 4 . Inner thickness t 3 is the thickness of intermediate segmented heater sub-assembly 140 proximate to inner peripheral surface 144 and outer thickness t 4 is the thickness of intermediate segmented heater sub-assembly 140 proximate to outer peripheral surface 143 .
[0116] Intermediate segmented heater sub-assembly 140 has a uniform thickness when thicknesses t 3 and t 4 are the same, and intermediate segmented heater sub-assembly 140 has thickness t 3 between outer peripheral surface 143 and inner peripheral surface 144 . Intermediate segmented heater sub-assembly 140 has a uniform thickness when thicknesses t 3 and t 4 are the same, and intermediate segmented heater sub-assembly 140 has thickness t 4 between outer peripheral surface 143 and inner peripheral surface 144 .
[0117] Intermediate segmented heater sub-assembly 140 has a uniform thickness when thicknesses t 3 and t 4 are the same and opposed surfaces 145 a and 145 d are spaced apart from each other by thickness t 3 . Intermediate segmented heater sub-assembly 140 has a uniform thickness when thicknesses t 3 and t 4 are the same, and opposed surfaces 145 a and 145 d are spaced apart from each other by thickness t 4 . In the embodiment in which intermediate segmented heater sub-assembly 140 has a uniform thickness, opposed surfaces 145 a and 145 b are parallel to each other. It should be noted that intermediate heater segments 140 a and 140 b have uniform thicknesses when intermediate segmented heater sub-assembly 140 has a uniform thickness.
[0118] FIG. 4 e is a side view of another embodiment of intermediate segmented heater sub-assembly 140 in region 149 , and FIG. 4 f is a corresponding perspective view of the embodiment of FIG. 4 e , wherein intermediate segmented heater sub-assembly 140 has a non-uniform thickness. Intermediate segmented heater sub-assembly 140 of FIGS. 4 e and 4 f correspond to intermediate segmented heater sub-assembly 140 of FIG. 1 c . In FIGS. 4 d and 4 e , intermediate segmented heater sub-assembly 140 has a non-uniform thickness because thicknesses t 3 and t 4 are unequal, and the thickness of intermediate segmented heater sub-assembly 140 is non-uniform between inner peripheral surface 144 and outer peripheral surface 143 . In this particular embodiment, thickness t 3 is greater than thickness t 4 . It should be noted, however, that thickness t 4 is greater than thickness t 3 in other embodiments. In the embodiment in which intermediate segmented heater sub-assembly 140 has a non-uniform thickness, opposed surfaces 145 a and 145 b are not parallel to each other.
[0119] Surfaces 145 a and 145 b can have many different shapes. For example, in FIG. 4 d , surfaces 145 a and 145 b are flat surfaces which extend parallel to each other because t 3 and t 4 are equal. In FIGS. 4 e and 4 f , surfaces 145 a and 145 b are flat surfaces which do not extend parallel to each other because t 3 and t 4 are not equal. In some embodiments, surfaces 145 a and 145 c are flat surfaces and, in other embodiments, surfaces 145 a and 145 c are curved surfaces or combinations thereof. In some embodiments, surfaces 145 a and 145 c are curved so they are concave and, in other embodiments, surfaces 145 a and 145 c are curved so they are convex.
[0120] FIG. 5 a is a top view of one embodiment of outer segmented heater sub-assembly 160 , FIG. 5 b is a perspective view of outer segmented heater sub-assembly 160 and FIG. 5 c is a cut-away side view of outer segmented heater sub-assembly 160 taken along a cut-line 5 c - 5 c of FIG. 5 a . In this embodiment, outer segmented heater sub-assembly 160 includes outer heater segments 160 a , 160 b , 160 c and 160 d . Outer heater segments 160 a , 160 b , 160 c and 160 d include opposed surfaces 165 a and 165 b , and are bounded by an outer peripheral surface 163 and inner peripheral surface 164 . Outer peripheral surface 163 extends adjacent to the outer periphery of heater assembly 100 ( FIGS. 1 a and 1 b ), and faces the outer periphery of heater assembly 100 . Inner peripheral surface 164 extends adjacent to outer gap 107 ( FIGS. 1 a and 1 b ), and faces intermediate segmented heater sub-assembly 140 . In this way, outer gap 107 is bounded by outer peripheral surface 143 and inner peripheral surface 163 . Outer gap 107 is dimensioned to inhibit the ability of current to flow between heater assemblies 140 and 160 . Outer segmented heater sub-assembly 160 includes a central opening 161 sized and shaped to receive intermediate segmented heater sub-assembly 140 ( FIGS. 1 a and 1 b ).
[0121] In this embodiment, outer segmented heater assembly includes contacts 162 a and 162 b , which are carried by intermediate heater segment 160 a . In this embodiment, outer segmented heater sub-assembly 160 includes contacts 162 c and 162 d , which are carried by intermediate heater segment 160 d . In this embodiment, outer segmented heater sub-assembly 160 includes contacts 162 e and 162 f , which are carried by intermediate heater segment 160 c . In this embodiment, outer segmented heater sub-assembly 160 includes contacts 162 g and 162 h , which are carried by intermediate heater segment 160 b.
[0122] In this embodiment, contacts 162 a and 162 h are spaced apart from each other by a radial gap 166 a . Further, outer heater segments 160 a and 160 b are spaced apart from each other by radial gap 166 a . In this embodiment, contacts 162 b and 162 c are spaced apart from each other by a radial gap 166 c . Further, outer heater segments 160 a and 160 d are spaced apart from each other by radial gap 166 c . In this embodiment, contacts 162 d and 162 e are spaced apart from each other by a radial gap 166 b . Further, outer heater segments 160 c and 160 d are spaced apart from each other by radial gap 166 b . In this embodiment, contacts 162 f and 162 g are spaced apart from each other by a radial gap 166 d . Further, outer heater segments 160 b and 160 c are spaced apart from each other by radial gap 166 d.
[0123] Radial gap 166 a is a radial gap because it extends along a radial line, which extends radially outward from center 103 of heater plate sub-assembly 110 . In this embodiment, radial gap 166 a is bounded by opposed radial gap surfaces 168 a and 168 h . Radial gap surfaces 168 a and 168 h extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 163 and inner peripheral surface 164 .
[0124] Radial gap 166 b is a radial gap because it extends along a radial line, which extends radially outward from center 103 of heater plate sub-assembly 110 . In this embodiment, radial gap 166 b is bounded by opposed radial gap surfaces 168 d and 168 e . Radial gap surfaces 168 d and 168 e extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 163 and inner peripheral surface 164 .
[0125] Radial gap 166 c is a radial gap because it extends along a radial line, which extends radially outward from center 103 of heater plate sub-assembly 110 . In this embodiment, radial gap 166 c is bounded by opposed radial gap surfaces 168 b and 168 c . Radial gap surfaces 168 b and 168 c extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 163 and inner peripheral surface 164 .
[0126] Radial gap 166 d is a radial gap because it extends along a radial line, which extends radially outward from center 103 of heater plate sub-assembly 110 . In this embodiment, radial gap 166 d is bounded by opposed radial gap surfaces 168 f and 168 g . Radial gap surfaces 168 f and 168 g extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral surface 163 and inner peripheral surface 164 .
[0127] Radial slot 166 a is dimensioned to inhibit the ability of current to flow between surfaces 168 a and 168 h . Radial slot 166 b is dimensioned to inhibit the ability of current to flow between surfaces 168 d and 168 e . Radial slot 166 c is dimensioned to inhibit the ability of current to flow between surfaces 168 b and 168 c . Radial slot 166 d is dimensioned to inhibit the ability of current to flow between surfaces 168 f and 168 g.
[0128] Outer segmented heater sub-assembly 160 flows heat through opposed surfaces 165 a and 165 b in response to a potential difference V 4 , V 5 , V 6 , and V 7 established between contacts 162 a and 162 b , between contracts 162 c and 162 d , between contacts 162 e and 162 f , between contracts 162 g and 162 h respectively. It should be noted that the current flows between contacts 162 a and 162 b in response to the potential difference established between contacts 162 a and 162 b and between contacts 162 c and 162 d in response to the potential difference established between contacts 162 c and 162 d , and between contacts 162 e and 162 f in response to the potential established between contacts 162 e and 162 f and between contacts 162 g and 162 h in response to the potential established between contacts 162 g and 162 h by the adjustable signals applied to the contacts as discussed above.
[0129] FIG. 5 d is a side view of outer segmented heater sub-assembly 160 in a region 169 of FIG. 5 c . As shown in FIG. 5 d , outer segmented heater sub-assembly 160 has inner and outer thicknesses t 5 and t 6 . Inner thickness t 5 is the thickness of outer segmented heater sub-assembly 160 proximate to inner peripheral surface 164 and outer thickness t 6 is the thickness of outer segmented heater sub-assembly 160 proximate to outer peripheral surface 163 .
[0130] Outer segmented heater sub-assembly 160 has a uniform thickness when thicknesses t 5 and t 6 are the same, and outer segmented heater sub-assembly 160 has thickness t 5 between outer peripheral surface 163 and inner peripheral surface 164 . Outer segmented heater sub-assembly 160 has a uniform thickness when thicknesses t 5 and t 6 are the same, and outer segmented heater sub-assembly 160 has thickness t 6 between outer peripheral surface 163 and inner peripheral surface 164 .
[0131] Outer segmented heater sub-assembly 160 has a uniform thickness when thicknesses t 5 and t 6 are the same, and opposed surfaces 165 a and 165 b are spaced apart from each other by thickness t 5 . Outer segmented heater sub-assembly 160 has a uniform thickness when thicknesses t 5 and t 6 are the same, and opposed surfaces 165 a and 165 b are spaced apart from each other by thickness t 6 . In the embodiment in which outer segmented heater sub-assembly 160 has a uniform thickness, opposed surfaces 165 a and 165 b are parallel to each other. It should be noted that outer heater segments 160 a , 160 b , 160 c and 160 d have uniform thicknesses when outer segmented heater sub-assembly 160 has a uniform thickness.
[0132] FIG. 5 e is a side view of another embodiment of outer segmented heater sub-assembly 160 in region 169 , and FIG. 5 f is a corresponding perspective view of the embodiment of FIG. 5 e , wherein outer segmented heater sub-assembly 160 has a non-uniform thickness. Outer segmented heater sub-assembly 160 of FIGS. 5 e and 5 f correspond to outer segmented heater sub-assembly 160 of FIG. 1 c . In FIGS. 5 d and 5 e , outer segmented heater sub-assembly 160 has a non-uniform thickness because thicknesses t 5 and t 6 are unequal, and the thickness of outer segmented heater sub-assembly 160 is non-uniform between inner peripheral surface 164 and outer peripheral surface 163 . In this particular embodiment, thickness t 5 is greater than thickness t 6 . It should be noted, however, that thickness t 6 is greater than thickness t 5 in other embodiments. In the embodiment in which outer segmented heater sub-assembly 160 has a non-uniform thickness, opposed surfaces 165 a and 165 b are not parallel to each other.
[0133] Surfaces 165 a and 165 b can have many different shapes. For example, in FIG. 5 d , surfaces 165 a and 165 b are flat surfaces which extend parallel to each other because t 5 and t 6 are equal. In FIGS. 5 e and 5 f , surfaces 165 a and 165 b do not extend parallel to each other because t 5 and t 6 are not equal. In some embodiments, surfaces 165 a and 165 c are flat surfaces and, in other embodiments, surfaces 165 a and 165 c are curved surfaces. In some embodiments, surfaces 165 a and 165 c are curved so they are concave and, in other embodiments, surfaces 165 a and 165 c are curved so they are convex.
[0134] FIG. 6 is a top view of one embodiment of a heater assembly 100 a . As will be discussed in more detail below, heater assembly 100 a can be used to heat a wafer. It is desirable to heat the wafer(s) in many different situations, such as when depositing a material thereon. Heater assembly 100 a can be used in a deposition system to heat the wafer. The wafer is heated to facilitate the ability to deposit material thereon. The material can be of many different types, such as semiconductor material.
[0135] In this embodiment, heater assembly 100 a includes a coiled heater 110 a , and an inner slotted heater ring 180 spaced from coiled heater sub-assembly 110 a by inner gap 105 . Heater assembly 100 a includes intermediate slotted heater sub-assemblies 181 a and 181 b spaced from slotted inner heater sub-assembly 180 by intermediate gap 106 . Heater assembly 100 a includes outer slotted heater sub-assemblies 182 a , 182 b , 183 c and 184 d spaced from slotted intermediate heater sub-assemblies 181 a and 181 b by outer gap 107 . It should be noted that inner gap 105 , intermediate gap 106 and outer gap 107 are annular gaps because they extend annularly around coiled heater sub-assembly 110 a , inner slotted ring heater sub-assemblies 180 , intermediate slotted heaters sub-assemblies 181 a and 181 b and outer slotted heater sub-assemblies 182 a , 182 b , 183 c and 184 d respectively.
[0136] Heater sub-assemblies 110 a , 180 , 181 a and 181 b and 182 a , 182 b , 183 c and 184 d can be constructed in many different ways, several of which will be discussed in more detail below.
[0137] It should also be noted that heater assembly 100 a , as shown in FIG. 6 , has a uniform thickness. Heater assembly 100 of FIG. 6 has a uniform thickness because the thicknesses of heaters 110 a , 180 , 181 a and 181 b and 182 a , 182 b , 183 c and 184 d have the same thickness values between inner gap 105 and the outer periphery of heaters 182 a , 182 b , 183 c and 184 d.
[0138] FIG. 7 is a top view of one embodiment of coiled heater 110 a . In this embodiment, coiled heater 110 a includes an inner ring 191 having a central opening 192 . In this embodiment, coiled heater 110 a includes coils 193 and 194 which are connected to opposed sides of inner ring 191 . Inner coils 193 and 194 are spaced apart from each other by gaps 195 a and 195 b , wherein gaps 195 a and 195 b extend between inner coils 193 and 194 and coil ring 191 .
[0139] FIGS. 8 a and 8 b are perspective and top views, respectively, of heater coil 170 of one embodiment of a heater. It should be noted that heater coil 170 can be included in a heater assembly, such as the heater assemblies discussed herein. For example, heater coil 170 can be included in heater assemblies 100 and 100 a . Heater coil 170 can be included in a heater assembly in many different ways. In some embodiments, heater coil 170 is included in an inner segmented heater 180 in FIG. 6 . In some embodiments, heater coil 170 is included in intermediate segmented heater 181 a and 181 b . In some embodiments, heater coil 170 is included in outer segmented heater 182 a , 182 b , 182 c and 182 d . Several of these embodiments will be discussed in more detail below.
[0140] In FIGS. 8 a and 8 b , heater coil 170 includes a plurality of inner and outer radial slots, wherein the inner radial slot faces an inner peripheral surface and the outer radial slot faces an outer peripheral surface. The inner and outer radial slots are radial gaps because they are lengthened along a radial line, such as radial line 104 of FIGS. 1 a and 6 , which extends radially outward from a center, such as center 103 . Further, the inner and outer radial slots are radial gaps because they are shortened transversely to the radial line.
[0141] In this embodiment, heater coil 170 includes an inner radial slot 176 a , which faces inner peripheral surface 174 . Inner radial slot 176 a is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Inner radial slot 176 a is bounded by a transverse coil segment 172 b and opposed radial segment 171 b and 171 c . Transverse segment 172 b is a transverse segment because it extends transversely to the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 b and 171 c are radial segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0142] It should be noted that a radial coil segment is lengthened in the radial direction and shortened in the transverse direction. The radial coil segment is lengthened in the radial direction and shorted in the transverse direction because the radial coil segment is longer in the radial direction and shorter in the transverse direction.
[0143] Further, a transverse coil segment is shortened in the radial direction and lengthened in the transverse direction. The transverse coil segment is shortened in the radial direction and lengthened in the transverse direction because the transverse coil segment is shorter in the radial direction and longer in the transverse direction.
[0144] In this embodiment, heater coil 170 includes outer radial slots 177 a and 177 b , which face outer peripheral surface 173 . Outer radial slot 177 a is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Outer radial slot 177 a is bounded by a transverse coil segment 172 a and opposed radial coil segments 171 a and 171 b . Transverse coil segment 172 a is a transverse coil segment because it extends along the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 a and 171 b are radial coil segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0145] Outer radial slot 177 b is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Outer radial slot 177 b is bounded by a transverse coil segment 172 c and opposed radial coil segments 171 c and 171 d . Transverse coil segment 172 c is a transverse coil segment because it extends along the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 c and 171 d are radial coil segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0146] FIG. 8 b shows that radial coil segments 171 a and 171 b are spaced apart from each other by a distance t 7 proximate to inner peripheral surface 174 . Further, radial coil segments 171 a and 171 b are spaced apart from each other by a distance t 8 proximate to outer peripheral surface 173 . In one embodiment, distance t 7 is less than distance t 8 . In another embodiment distance t 7 is the same as distance t 8 . In another embodiment distance t 7 is greater than as distance t 8 .
[0147] In this embodiment, radial coil segments 171 b and 171 c are spaced apart from each other by a distance t 9 proximate to outer peripheral surface 173 , as shown in FIG. 8 b . Further, radial coil segments 171 b and 171 c are spaced apart from each other by a distance t 10 proximate to inner peripheral surface 174 . In this embodiment, distance t 10 is less than distance t 9 . In another embodiment distance t 10 is the same as distance t 9 . In another embodiment distance t 10 is greater than as distance t 9 .
[0148] In this embodiment, radial coil segments 171 c and 171 d are spaced apart from each other by distance t 7 proximate to inner peripheral surface 174 , as shown in FIG. 8 b . Further, radial coil segments 171 c and 171 d are spaced apart from each other by a distance t 8 proximate to outer peripheral surface 173 . In this embodiment, distance t 7 is less than distance t 8 . In another embodiment distance t 7 is the same as distance t 8 . In another embodiment distance t 7 is greater than as distance t 8 .
[0149] As mentioned above, a heater assembly has a uniform thickness in some embodiments, and a non-uniform thickness in other embodiments. Examples of heater assemblies having uniform and non-uniform thicknesses are shown in FIGS. 1 b and 1 c . In FIGS. 8 a and 8 b , heater coil 170 has a uniform thickness because the thicknesses of heater coil 170 proximate to and between outer peripheral surface 173 and inner peripheral surface 174 are the same. For example, in this embodiment, heater coil 170 has a thickness t 11 proximate to inner peripheral surface 174 and a thickness t 12 proximate to outer peripheral surface 173 , wherein thicknesses t 11 and t 12 are the same. In this embodiment, the thickness of heater coil 170 between outer peripheral surface 173 and inner peripheral surface 174 is thickness t 11 . Further, the thickness of heater coil 170 between outer peripheral surface 173 and inner peripheral surface 174 is thickness t 12 . In this way, heater coil 170 has a uniform thickness. An example of a heater coil with a non-uniform thickness will be discussed in more detail presently.
[0150] FIGS. 9 a and 9 b are perspective and top views, respectively, of another embodiment of a heater coil, denoted as heater coil 170 a . It should be noted that heater coil 170 a can be included in a heater assembly, such as the heater assemblies discussed herein. For example, heater coil 170 a can be included in an inner segmented heater 181 in FIG. 6 . In some embodiments, heater coil 170 is included in intermediate segmented heater 181 a and 181 b . In some embodiments, heater coil 170 is included in outer segmented heater 182 a , 182 b , 182 c and 182 d . Several of these embodiments will be discussed in more detail below.
[0151] In FIGS. 9 a and 9 b , heater coil 170 a includes a plurality of inner and outer radial slots, wherein the inner radial slot faces an inner peripheral surface and the outer radial slot faces an outer peripheral surface. As mentioned above, the inner and outer radial slots are radial gaps because they are lengthened along a radial line, such as radial line 104 of FIGS. 1 a and 6 , which extends radially outward from a center, such as center 103 , of the heater assembly. Further, the inner and outer radial slots are radial gaps because they are shortened transversely to the radial line.
[0152] In this embodiment, heater coil 170 a includes inner radial slot 176 a , which faces inner peripheral surface 174 . As mentioned above, inner radial slot 176 a is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Inner radial slot 176 a is bounded by a transverse coil segment 172 b and opposed radial coil segments 171 b and 171 c . Transverse coil segment 172 b is a transverse coil segment because it extends transversely to the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 b and 171 c are radial coil segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0153] As mentioned above, a radial coil segment is lengthened in the radial direction and shortened in the transverse direction. The radial coil segment is lengthened in the radial direction and shorted in the transverse direction because the radial coil segment is longer in the radial direction and shorter in the transverse direction.
[0154] Further, a transverse coil segment is shortened in the radial direction and lengthened in the transverse direction. The transverse coil segment is shortened in the radial direction and lengthened in the transverse direction because the transverse coil segment is shorter in the radial direction and longer in the transverse direction.
[0155] In this embodiment, heater coil 170 a includes outer radial slots 177 a and 177 b , which face outer peripheral surface 173 . As mentioned above, outer radial slot 177 a is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Outer radial slot 177 a is bounded by a transverse coil segment 172 a and opposed radial coil segments 171 a and 171 b . Transverse coil segment 172 a is a transverse coil segment because it extends along the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 a and 171 b are radial coil segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0156] As mentioned above, outer radial slot 177 b is a radial gap because it extends along a radial line, such as radial line 104 of FIGS. 1 a and 6 . Outer radial slot 177 b is bounded by a transverse coil segment 172 c and opposed radial coil segments 171 c and 171 d . Transverse coil segment 172 c is a transverse coil segment because it extends along the radial line, such as radial line 104 of FIGS. 1 a and 6 . Radial coil segments 171 c and 171 d are radial coil segments because they extend along the radial line, such as radial line 104 of FIGS. 1 a and 6 .
[0157] As mentioned above, radial coil segments 171 a and 171 b are spaced apart from each other by a distance t 7 proximate to inner peripheral surface 174 , as shown in FIG. 9 b . Further, radial coil segments 171 a and 171 b are spaced apart from each other by a distance t 8 proximate to outer peripheral surface 173 . In this embodiment, distance t 7 is less than distance t 8 . In another embodiment distance t 7 is the same as distance t 8 . In another embodiment distance t 7 is greater than as distance t 8 .
[0158] As mentioned above, radial coil segments 171 b and 171 c are spaced apart from each other by a distance t 9 proximate to outer peripheral surface 173 , as shown in FIG. 9 b . Further, radial coil segments 171 b and 171 c are spaced apart from each other by a distance t 10 proximate to inner peripheral surface 174 . In this embodiment, distance t 10 is less than distance t 9 . In another embodiment distance t 10 is the same as distance t 9 . In another embodiment distance t 10 is greater than as distance t 9 .
[0159] As mentioned above, radial coil segments 171 c and 171 d are spaced apart from each other by distance t 7 proximate to inner peripheral surface 174 , as shown in FIG. 9 b . Further, radial coil segments 171 c and 171 d are spaced apart from each other by a distance t 8 proximate to outer peripheral surface 173 . In this embodiment, distance t 7 is less than distance t 8 . In another embodiment distance t 7 is the same as distance t 8 . In another embodiment distance t 7 is greater than distance t 8 .
[0160] As mentioned above, a heater assembly has a uniform thickness in some embodiments, and a non-uniform thickness in other embodiments. Examples of heater assemblies having uniform and non-uniform thicknesses are shown in FIGS. 1 b and 1 c . In FIGS. 8 a and 8 b , heater coil 170 has a uniform thickness. In FIGS. 9 a and 9 b , however, heater coil 170 a has a non-uniform thickness.
[0161] Heater coil 170 a has a non-uniform thickness because the thicknesses of heater coil 170 proximate to and between outer peripheral surface 173 and inner peripheral surface 174 are not the same. For example, in this embodiment, heater coil 170 has a thickness t 13 proximate to inner peripheral surface 174 and a thickness t 14 proximate to outer peripheral surface 173 , wherein thicknesses t 13 and t 14 are not the same. In this embodiment, the thickness of heater coil 170 between outer peripheral surface 173 and inner peripheral surface 174 is not thickness t 13 . Further, the thickness of heater coil 170 between outer peripheral surface 173 and inner peripheral surface 174 is not thickness t 13 . In this way, heater coil 170 has a non-uniform thickness.
[0162] FIGS. 10 a and 10 b are top and side views, respectively, of one embodiment of a coiled inner segmented heater assembly 181 . Coiled inner segmented heater assembly 181 is a coiled heater assembly because it includes a heater coil. In this embodiment, coiled inner segmented heater assembly 181 includes heater coil 170 of FIGS. 8 a and 8 b , as indicated in a region 179 of FIG. 10 a . However, in some embodiments, coiled inner segmented heater assembly 181 includes heater coil 170 a of FIGS. 9 a and 9 b . In this way, coiled inner segmented heater assembly 181 is a coiled heater assembly.
[0163] In this embodiment, coiled inner segmented heater assembly 181 includes opposed gapped surfaces 175 a and 175 b , and is bounded by outer peripheral gapped surface 173 and inner peripheral gapped surface 174 . Outer peripheral gapped surface 173 extends adjacent to intermediate gap 106 ( FIG. 6 ), and inner peripheral gapped surface 174 extends adjacent to inner gap 105 ( FIG. 6 ). In this way, inner gap 105 is bounded by outer peripheral surface 113 and inner peripheral gapped surface 174 . Inner gap 105 is dimensioned to inhibit the ability of current to flow between heater assemblies 180 and 181 . Inner segmented heater assembly 181 includes central opening 121 , which is sized and shaped to receive coiled heater plate 180 ( FIGS. 6 and 7 ).
[0164] Opposed gapped surfaces 175 a and 175 b are gapped surfaces because inner radial slot 176 extends therethrough. Opposed gapped surfaces 175 a and 175 b are gapped surfaces because outer radial slot 177 extends therethrough. Outer peripheral gapped surface 173 and inner peripheral gapped surface 174 are gapped surfaces because inner radial slot 176 extends therethrough. Outer peripheral gapped surface 173 and inner peripheral gapped surface 174 are gapped surfaces because outer radial slot 177 extends therethrough. Examples of surfaces that are not gapped surfaces are discussed in more detail above.
[0165] In this embodiment, coiled inner segmented heater assembly 181 includes contacts 172 a and 172 b , which are spaced apart from each other by a radial gap 176 . Coiled inner segmented heater assembly 181 flows heat through opposed surfaces 145 a and 145 b in response to a potential difference V 1 established between contacts 172 a and 172 b . Coiled inner segmented heater assembly 181 flows heat through opposed surfaces 175 a and 175 b in response to a current flowing between contacts 172 a and 172 b . It should be noted that the current flows between contacts 172 a and 172 b in response to the potential difference established between contacts 172 a and 172 b.
[0166] Radial gap 126 is a radial gap because it extends along a radial line 104 , which extends radially outward from a center 103 of heater plate sub-assembly 110 ( FIG. 1 a ). It should be noted that, in this embodiment, center 103 of heater plate sub-assembly 110 corresponds to a center of heater assembly 100 . In this embodiment, radial gap 126 is bounded by opposed radial gap surfaces 128 a and 128 b . Radial gap surfaces 128 a and 128 b extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral gapped surface 173 and inner peripheral gapped surface 174 .
[0167] FIGS. 11 a and 11 b are top and side views, respectively, of one embodiment of a coiled intermediate segmented heater assembly 182 . Coiled intermediate segmented heater assembly 182 is a coiled heater assembly because it includes heater coils. In this embodiment, coiled intermediate segmented heater assembly 182 includes heater coil 170 of FIGS. 8 a and 8 b , as indicated in a region 179 of FIG. 11 a . However, in some embodiments, coiled intermediate segmented heater assembly 182 includes heater coil 170 a of FIGS. 9 a and 9 b . In this way, coiled intermediate segmented heater assembly 182 is a coiled heater assembly.
[0168] In this embodiment, coiled intermediate segmented heater assembly 182 includes opposed gapped surfaces 175 a and 175 b , and is bounded by outer peripheral gapped surface 173 and inner peripheral gapped surface 174 . Outer peripheral gapped surface 173 extends adjacent to intermediate gap 106 ( FIG. 6 ), and inner peripheral gapped surface 174 extends adjacent to inner gap 105 ( FIG. 6 ). In this way, inner gap 105 is bounded by outer peripheral surface 113 and inner peripheral gapped surface 174 . Inner gap 105 is dimensioned to inhibit the ability of current to flow between heater assemblies 181 and 182 . Intermediate segmented heater assembly 182 includes central opening 121 , which is sized and shaped to receive coiled heater plate 180 ( FIG. 6 ).
[0169] In FIGS. 11 a and 11 b opposed gapped surfaces 142 a and 142 b and opposed gapped surfaces 142 c and 142 d are gapped surfaces because inner radial slot 146 a and 146 b extends therethrough respectively.
[0170] In this embodiment, coiled inner segmented heater assembly 182 includes contacts 142 a and 142 c and contacts 142 b and 142 d , which are spaced apart from each other by a radial gap 146 a and 146 b . Coiled inner segmented heater assembly 182 flows heat through opposed surfaces 175 a and 175 b in response to a potential difference established between contacts 142 a and 142 c and a potential difference established between contacts 142 b and 142 d . Coiled inner segmented heater assembly 182 flows heat through opposed surfaces 175 a and 175 b in response to a current flowing between contacts 142 a and 142 c and between contacts 142 b and 142 d.
[0171] Radial gap 146 a and 146 b is a radial gap because it extends along a radial line 104 , which extends radially outward from a center 103 of heater plate sub-assembly 110 ( FIG. 1 a ). It should be noted that, in this embodiment, center 103 of heater plate sub-assembly 110 corresponds to a center of heater assembly 100 . In this embodiment, radial gap 146 a is bounded by opposed radial gap surfaces 148 a and 148 d and radial gap 146 b is bounded by opposed radial gap surfaces 188 b and 188 c.
[0172] Radial gap surfaces 148 a and 148 d and radial gap surfaces 188 b and 188 c extend radially outward from center 103 of heater plate sub-assembly 110 , and between outer peripheral gapped surface 173 and inner peripheral gapped surface 174 .
[0173] FIGS. 12 a and 12 b are top and side views, respectively, of one embodiment of a coiled outer segmented heater assembly 183 . Coiled outer segmented heater assembly 183 is a coiled heater assembly because it includes heater coils. In this embodiment, coiled outer segmented heater assembly 183 includes heater coil 170 of FIGS. 8 a and 8 b , as indicated in a region 179 of FIG. 12 a . However, in some embodiments, coiled inner segmented heater assembly 183 includes heater coil 170 a of FIGS. 9 a and 9 b . In this way, coiled outer segmented heater assembly 183 is a coiled heater assembly.
[0174] In this embodiment, coiled outer segmented heater assembly 183 includes radial gaps 166 a , 166 bb , 166 c and 166 d between outer peripheral gapped surface 173 and inner peripheral gapped surface 164 . Inner peripheral gapped surface 174 extends adjacent to inner gap 107 ( FIG. 6 ). In this way, inner gap 107 is bounded by outer peripheral surface 143 and inner peripheral gapped surface 164 . Inner gap 107 is dimensioned to inhibit the ability of current to flow between heater assemblies 182 and 183 . Intermediate segmented heater assembly 183 includes central opening 161 , which is sized and shaped to receive coiled heater plate 181 a and 181 b ( FIG. 6 ).
[0175] In this embodiment, coiled outer segmented heater assembly 18 e includes contacts 162 a and 162 b , contacts 162 c and 162 d and contacts 162 e and 162 f which are spaced apart from each other by a radial gap 166 a , 166 bb , 166 c and 166 d . Coiled outer segmented heater assembly 183 flows heat through opposed surfaces 165 a and 165 b in response to a potential differences established between contacts 162 a and 162 b , between contacts 162 c and 162 d , between contacts 162 e and 162 f and between contacts 162 g and 162 h . Coiled outer segmented heater assembly 183 flows heat through opposed surfaces 162 a and 162 b in response to a current flowing between contacts 162 a and 162 b , between contacts 162 c and 162 d , between contacts 162 e and 162 f and between contacts 162 g and 162 h , due to a potential difference established between contacts 162 c and 162 d , a potential difference established between contacts 162 e and 162 f and a potential difference established between contacts 162 g and 162 h . Radial gaps 1661 , 166 b , 166 c and 166 d are radial gap because it extends along a radial line 104 , which extends radially outward from a center 103 of heater plate sub-assembly 110 ( FIG. 1 a ). It should be noted that, in this embodiment, center 103 of heater plate sub-assembly 110 corresponds to a center of heater assembly 100 .
[0176] It should be noted that a heater assembly can include many different combinations of the components discussed above. For example, the heater assembly can include various combinations of components from heater assembly 100 and 200 a . In this way, the heater assembly can be assembled to provide desired heating properties. Several examples of heater assemblies having different combinations of components will be discussed in more detail presently.
[0177] FIG. 13 a is a top view of one embodiment of a heater assembly 100 b . In this embodiment, heater assembly 100 b includes heater plate 110 ( FIG. 2 a ) and coiled inner segmented heater 181 ( FIG. 10 a ). Further, heater assembly 100 b includes coiled intermediate segmented heater 182 ( FIG. 11 a ) and coiled outer segmented heater 183 ( FIG. 12 a ). It should be noted that heater assembly 100 b can be of uniform thickness, as shown in FIG. 1 b , or of non-uniform thickness, as shown in FIG. 1 c.
[0178] FIG. 13 b is a top view of one embodiment of a heater assembly 100 c . In this embodiment, heater assembly 100 c includes heater plate 110 ( FIG. 2 a ) and inner segmented heater sub-assembly 120 ( FIG. 3 a ). Further, heater assembly 100 c includes coiled intermediate segmented heater 182 ( FIG. 11 a ) and coiled outer segmented heater 183 ( FIG. 12 a ). It should be noted that heater assembly 100 c can be uniform, as shown in FIG. 1 b , or non-uniform, as shown in FIG. 1 c.
[0179] FIG. 13 c is a top view of one embodiment of a heater assembly 100 d . In this embodiment, heater assembly 100 d includes heater plate 110 ( FIG. 2 a ) and coiled inner segmented heater 181 ( FIG. 10 a ). Further, heater assembly 100 d includes intermediate segmented heater sub-assembly 140 ( FIG. 4 a ) and coiled outer segmented heater 183 ( FIG. 12 a ). It should be noted that heater assembly 100 d can be uniform, as shown in FIG. 1 b , or non-uniform, as shown in FIG. 1 c.
[0180] FIG. 13 d is a top view of one embodiment of a heater assembly 100 e . In this embodiment, heater assembly 100 e includes heater plate 110 ( FIG. 2 a ) and coiled inner segmented heater 181 ( FIG. 10 a ). Further, heater assembly 100 e includes coiled intermediate segmented heater 182 ( FIG. 11 a ) and outer segmented heater sub-assembly 160 ( FIG. 5 a ). It should be noted that heater assembly 100 e can be uniform, as shown in FIG. 1 b , or non-uniform, as shown in FIG. 1 c.
[0181] FIG. 13 e is a top view of one embodiment of a heater assembly 100 f . In this embodiment, heater assembly 100 f includes heater plate 110 ( FIG. 2 a ) and inner segmented heater sub-assembly 120 ( FIG. 3 a ). Further, heater assembly 100 f includes intermediate segmented heater sub-assembly 140 ( FIG. 4 a ) and outer segmented heater sub-assembly 160 ( FIG. 5 a ). It should be noted that heater assembly 100 f can be uniform, as shown in FIG. 1 b , or non-uniform, as shown in FIG. 1 c.
[0182] In this embodiment, heater assembly 100 f ( FIG. 13 e ) includes one or more segmented heater assemblies positioned around outer segmented heater sub-assembly 160 , as indicated by the ellipses of FIG. 13 e . The number of segmented heater assemblies of heater assembly 100 f is chosen in response to an area it is desired to heat. In general, the number of segmented heater assemblies of heater assembly 100 f increases and decreases as the number of wafers increases and decreases, or as the size of the susceptor increases or decreases respectively.
[0183] FIG. 14 a is a cut-away side view of a deposition system 200 . Deposition system 200 can be of many different types, such as a chemical vapor deposition (CVD) system. In one particular, embodiment, deposition system 200 is a metalorganic chemical vapor deposition (MOCVD) system. Deposition system 200 can be used to deposit many different types of material, such as semiconductor material. One particular type of semiconductor material that can be deposited using deposition system 200 is a semiconductor nitride. There are many different types of semiconductor nitrides that can be deposited using deposition system 200 , such as gallium nitride and alloys thereof. There are many different alloys of gallium nitride, such as indium gallium nitride and aluminum gallium nitride, among others.
[0184] It should be noted that the materials deposited using deposition system can be used in many different types of semiconductor devices, such as electrical devices and optoelectronic devices. Some examples of electrical devices include diodes and transistors, among others. Examples of optoelectronic devices include light emitting diodes, semiconductor lasers, photo-detectors and solar cells, among others.
[0185] In this embodiment deposition system 200 ( FIG. 14 a ) includes:
a. A reactor housing 204 usually fluid cooled and constructed from materials such as quartz, aluminum or stainless steel, b. A reactor chamber 204 a top and 204 b bottom bounded by housing 204 , c. A process zone 108 bounded by process chamber 204 a and 204 b, d. A rotatable susceptor 205 of one or more pieces carried by pedestal 213 supporting the wafer(s) 206 in the process zone 108 , further a rotation motor 207 and a susceptor lift/wafer lift 208 are operatively coupled to pedestal(s) 213 , e. A heater assembly 100 as in FIG. 1 a for example, mounted above and below the reactor chamber 204 a / 204 b to provide adjustable amounts of heat to the reactor chamber 102 , susceptor 205 and wafers 206 , f. A temperature/thermal sensor(s) 203 sensing the wafer(s) 206 , susceptor(s) 205 or heater assembly(ies) 100 or combinations thereof; further, temperature sensors include but are not limited to thermocouples, reflectometers or pyrometers. Purged sealed ports/view ports outside of the reactor chamber environment may be arranged to accommodate temperature/thermal sensor(s) 203 such as thermocouples and or pyrometers. There may also be holes (not shown) in reactor chamber 204 a / 204 b for the temperature sensor(s) 203 . g. A system controller 201 and a temperature control system 202 providing adjustable power signals S T to the heater assembly(ies) 100 via heater terminals 217 and 218 , further temperature controller 202 receives temperature signals S c from temperature/thermal sensor 203 via system controller 201 . Further, system controller 201 controls the movement of sealed access door 215 to allow loading and unloading the wafer and sealing of the loading port 210 . System controller 201 also controls wafer movement, process gas sequencing and gas flow to reactor chamber 204 a / 204 b , and other functions such as purge flows, process times, cooling flows and safety controls. Further, system controller 201 also controls rotation motor 207 and susceptor lift mechanism 208 via signal S c . h. Heat shields 209 and heat shield liners 209 a disposed between the heater assembly(ies) 100 and the reactor housing to minimize heat transfer/loss from the heater assembly(ies) 100 into the reactor housing 204 , and provide reradiating surfaces to heater assembly(ies) 100 and reactor chamber 204 a / 204 b . In an embodiment, reactor chamber 204 a / 204 b , susceptor(s) 205 and heat shield(s) 209 and 209 a are made of a material such as but not limited to quartz, silicon carbide and silicon carbide coated graphite. Further, liner heat shield 209 a is arranged to protect the interior surfaces of housing 204 . i. The amount of heat provided by each heater sub-assembly such as heater 110 , 120 , 140 and 160 of the heater assembly 100 is controllable. The amount of heat provided by a heater sub-assembly such as heater 110 , 120 , 140 and 160 of the heater assembly 100 is adjustable to adjust the temperature of the reactor chamber 204 a / 204 b , the susceptor 205 and or the wafer(s) 206 . The amount of heat provided by each heater sub-assembly such as heater 110 , 120 , 140 and 160 of the heater assembly 100 is adjustable to adjust the temperature of the inlet gas. The amount of heat provided by each heater sub-assembly such as heater 110 , 120 , 140 and 160 of the heater assembly 100 is adjustable in response to adjusting a current flow therethrough. j. The deposition system 200 is capable of operating at pressures above or below atmospheric pressure.
[0196] In this embodiment deposition system 200 ( FIG. 14 a ) includes:
k. A gas inlet and wafer loading duct 214 and a gas exhaust duct 214 a connected respectively to inlet/loading port 210 and exhaust port 210 a, l. Upstream and downstream gas inlet conduit(s) 211 and 212 are connected to gas inlet and loading duct 214 to supply process gases to reactor chamber 204 a / 204 b . The gas inlet and loading duct 214 also serves as access for loading and unloading the wafer(s) 206 to and from the reactor chamber 204 a / 204 b through loading port 210 via the sealed access door 215 controlled by system controller 201 . Gas exhaust duct(s) 214 a removes exhaust gases from reactor chamber 204 a / 204 b out exhaust port 210 a . Gas inlet and loading duct(s) 210 and gas exhaust duct(s) 210 , susceptor 205 and reactor chamber 204 a / 204 b are made of one or more pieces of materials such as but not limited to silicon carbide, and silicon carbide coated graphite. m. A top and bottom sealed/purged cover box 204 c is sealed to housing 204 enclosing electrical terminals 217 and 218 which supply adjustable power signals to heater assembly(ies) 100 (only one power signal to the top and bottom heater assembly 100 is shown for simplicity).
[0200] FIG. 14 b is cross sectional view of the heater assemblies 100 such as shown in FIG. 1 a , FIG. 1 b , and FIG. 1 d showing heater sub-assemblies 110 , 120 , 140 and 160 including process chamber 204 a / 204 b , susceptor 205 and wafers 206 and the gas inlet and loading duct 210 , the upstream gas inlet conduit 211 and the downstream gas inlet conduit 212 and exhaust duct 210 b of deposition system 200 . In this embodiment the temperature control system 202 is connected to each heater sub-assembly 110 , 120 , 140 and 160 of heater assembly 100 top and bottom by heater terminals 217 a through 217 g and 218 a through 218 g respectively, thereby providing adjustable power signals S T1a through S T7a and S T1b through S T7b to each heater sub-assembly 110 , 120 , 140 and 160 of heater assembly 100 both top and bottom (only one connection is shown for each heater for the sake of simplicity). Each heater sub-assembly 110 , 120 , 140 and 160 of top and bottom heater assembly 100 provides adjustable amounts of heat to the top and bottom of the reactor chamber 204 a / 204 b , to susceptor 205 and wafers 206 on susceptor 205 of process zone 108 of disposition system 200 . The proper selection of heater sub-assembly shape and number heater sub-assemblies as previously discussed provides the ability to produce a heat/temperature profile across the susceptor 205 in process zone 108 resulting in a temperature profile as depicted in FIG. 1 g.
[0201] FIG. 14 c is cross sectional plan view along cut line 14 b - 14 b of FIG. 14 b of deposition system 200 showing wafer(s) 206 on the rotatable susceptor 205 in process zone 108 . In this embodiment, a plurality of gas(es) 230 and 231 are controlled by gas flow control devices and on/off valve(s) 230 a through 230 b and 231 a through 231 b that control the flow of the plurality of gases 230 and 231 . The plurality of gas(es) 230 and 231 are then introduced into to the gas inject conduits 211 a through 211 b and 212 a through 212 b which feed the plurality of gas(es) 230 and 231 gas into the inlet/loading duct 214 and then over the wafers 206 on susceptor 205 at an adjustable heat/temperature as discussed above in process zone 108 . This provides multiple sub-process zones (not shown) of process zone 108 in which the heat/temperature and the gas flow(s) of the sub-process zones are controlled in order to deposit layers of uniform thickness and composition on the wafer 206 on rotating susceptor 205 . Effluent gases exit via exhaust duct 214 a.
[0202] FIG. 14 d is a cross section plan view of heater array 100 along cut line 14 b 1 - 14 b 1 of FIG. 14 b of deposition system 200 showing a representative upper heater assembly 100 (Reference FIG. 1 a ) consisting of heater sub-assemblies 110 , 120 , 140 a and 140 b and 160 a , 160 b , 160 c and 160 d . The annular gaps 105 , 106 and 107 as previously described are also shown. Again, a plurality of gas(es) 230 and 231 are controlled by gas flow control devices and on/off valve(s) 230 a through 230 b and 231 a through 231 b that control the flow of the gases 230 and 231 . The plurality of gas(es) 230 and 231 are then introduced into the gas inject conduits 211 a through 211 b and 212 a through 212 b which feed the plurality of gas(es) 230 and 231 gas inlet/loading duct 214 . The gasses then pass through the reactor chamber 240 / 240 a where the plurality of gasses 230 and 231 are selectively heated by the sub-assembly heaters of heater assembly 100 both top and bottom along with heating the wafers 206 and susceptor 205 of FIG. 14 c to provide a deposition of uniform thickness and composition on the wafer(s) 205 while minimizing the wafer temperature differential in the vertical and horizontal direction. Effluent gases exit via exhaust duct 214 a.
[0203] FIG. 14 e is an expanded view of the upper and lower heater arrays 100 of deposition system 200 . Each heater 110 , 120 , 130 and 140 has an electrically conductive transitory connection 112 , 122 , 142 and 162 designed to minimize heat transfer but maximize electrical conduction in the transition from heater materials to electrical heater terminals 217 a through 217 g and 218 a through 218 g which are then connected to adjustable power signals S T1a through S T7a and S T1b through S T7b to each heater sub-assembly 110 , 120 , 140 and 160 of heater assembly 100 both top and bottom individually controlled or controlled in groups/zones. This is accomplished by arranging temperature sensor(s) 203 from FIG. 14 a and heater sub-assemblies 110 , 120 , 140 and 160 to establish independently controlled zones of heat for example, of the front, rear, left, right and center sections (not shown) of the process zone 108 thereby compensating for the different thermal requirement/radiation losses within each zone to produce a uniform temperature across and through the susceptor 205 and wafer(s) 206 . The bottom heater assembly 100 may or may not be parallel and coincident to the top heater assembly 100 . The ability to control the temperatures in general of the individual heater sub-assemblies or in multiple independent groups of heater sub-assemblies is a significant advantage of this invention as can be seen in FIG. 14 f which shows a temperature profile 190 of a wafer in a system as describe herein in FIG. 14 a versus the temperature profile 191 of a wafer of a induction heated prior art system and a temperature profile 192 of a wafer in an IR lamp heated prior art system. This “new technology” describe herein far exceeds the others with a ±0.5° C. temperate uniformity across a 150 mm wafer versus ±3.1° C. and ±2.4° C. for the induction heated and IR lamp heated system respectively.
[0204] FIG. 15 a is a side cross-sectional view of reactor chamber 204 a / 204 b of deposition system 200 a . FIG. 15 b is an expanded cross sectional side view of the gas injection scheme as defined by region 219 of FIG. 14 b . The upstream gas inlet conduits 211 is disposed so as to independently inject/spread an individually controlled flow of a process gas(es) as described in FIGS. 14 c and 14 d , being either carrier and or reactant gases 230 , perpendicularly into the interior of gas inlet and loading duct 214 at port 226 being a hole, multiple holes, or slit(s) of a size 228 such that a substantially laminar flow/gas velocity profile 236 of the carrier and or reactant gases is established with an attendant boundary layer 232 . Downstream gas inlet conduit(s) 212 is positioned downstream of the upstream gas inlet conduit 211 in the laminar flow region. Downstream gas inlet port(s) 225 , may be designed as a slit(s) or hole(s) of size 227 with a upstream dimension 227 a and a downstream dimension 227 b shaped to inject a process and or carrier gas 238 utilizing the Coanda effect* substantially tangentially into the boundary layer 232 of the laminar flow/gas velocity profile 236 produced by upstream gas inlet port(s) 226 and gas inlet and loading duct 214 such that the gasses injected by downstream gas inlet port(s) substantially attach themselves to the lower inside surface of gas inlet and loading duct 214 and flow in streams closely over and parallel to the inside bottom surface of the gas inlet and loading duct 214 and then over the top surface of wafers 206 on susceptor 205 . The embodiment of this gas introduction scheme maximizes the reaction efficiency of the plurality of process gas(es) 231 with the wafer(s) 206 on susceptor 205 thereby maximizing the deposition rate and conversion efficiency of gas(es) 238 and minimizing reactant gas depletion across the susceptor. This tangential Coanda gas introduction systems is also capability of separately delivering reactant gases 230 and 231 to the process zone 108 (such as ammonia and Trimethylgallium commonly used in manufacturing High Brightness LEDs, these reactant can also be delivered to the process zone 108 via separate Coanda port(s) 225 both methods which eliminate premature gas reactions which result in clogging, plugging, particle generation in the gas delivery system or reactor chamber.
n. *(The Coanda effect is briefly described as the tendency of a fluid jet to be attracted to a nearby surface [1] . The principle was named after Romanian aerodynamics pioneer Henri Coand{hacek over (a)}, who was the first to recognize the practical application of the phenomenon in aircraft development. Much is published in literature and text books on aeronautical boundary layer injection, the Coanda effect and boundary layer deposition physics). 1 From Wikipedia
[0206] FIG. 15 c is a pictorial view of the one of the upstream gas inlet ports 226 and one of the downstream gas inlet ports 225 .
[0207] FIG. 15 d is an expanded view along cut line 15 d - 15 d of FIG. 15 c of one the upstream gas inlet port 226 which is fed by gas inlet conduit 211 and the tangential inject port 225 which is fed by gas inlet conduit 212 .
[0208] FIG. 15 e is a plan view of the upstream gas injection system of deposition system 200 . In this embodiment a plurality of gasses are controlled by a plurality of flow control devices and on off valves 231 a , 231 b , 231 c , 231 d and 231 e feeding upstream conduits 211 a , 211 b , 211 c , 211 d and 211 e in turn feeding tangential gas injection port assembly 226 a , 226 b , 226 c , 226 d and 226 e wherein the gas is injected into inlet gas inlet and loading duct 214 then over the tangential gas injection port assembly 229 a , 229 b , 229 c , 229 d and 229 e . The plurality of gases then passing over the wafers 206 on susceptor 205 in reactor chamber 204 b and then out the exhaust duct 210 a.
[0209] FIG. 15 f is a plan view of the downstream gas inject embodiment of deposition system 200 . In this embodiment a plurality of gasses are controlled by a plurality of flow control devices and on off valves 230 a , 230 b , 230 c , 230 d and 230 e feeding downstream conduits 212 a , 212 b , 212 c , 212 d and 212 e in turn feeding tangential gas injection port assembly 229 a , 229 b , 229 c , 229 d and 229 e wherein the gas is injected into gas inlet and loading duct 214 substantially tangentially out of ports 225 a , 225 b , 225 c , 225 d , and 225 e then over the wafers 206 on susceptor 205 in reactor chamber 204 b and then out the exhaust duct 214 a.
[0210] The upstream and downstream gas inlet conduit(s) 211 and 212 are constructed of one or more pieces of a suitable materials such as silicon carbide, silicon carbide coated graphite or graphite or combinations thereof. The number of upstream conduits 211 and downstream conduits 212 can be added or subtracted as determined by the process deposition requirements of the deposition system 200 and the size of the susceptor 205 and wafer(s) 206 .
[0211] FIGS. 16 a , 16 b and 16 c shows a cross sectional view, an exploded cross sectional view and plan view respectively of a vertical gas inject scheme of deposition system 200 b . In this embodiment, a double walled multi gas chamber upper plate 204 d replaces the upper reactor chamber (plate) 204 a of FIG. 14 a . below heater assembly 100 a . A plurality of separate gas inlet conduits 220 a , 220 b , 200 c , 220 d , 220 d , 220 e , 220 f , 220 g on the uppermost plate 242 a each connected to a plurality of gas channel circular segments, circles or rings 245 a , 245 b , 245 c , 245 d , 245 e , 245 f , 245 h and 245 g each having a uppermost plate 242 and bottom plate 243 and separators 244 forming a gas cavity/plenum(s) 245 a and 245 b , for example as shown in FIG. 16 b , with an array of holes 224 a and 224 b in bottom plate 243 for vertically impinging inlet gas(es) 224 c and 224 d (C onto the wafers 206 on susceptor 205 or comingling with the horizontal gas flow from ports 226 and or 225 .
[0212] Each gas inlet ports 220 a , 220 b , 200 c , 220 d , 220 d , 220 e , 220 f , 220 g are connected to a gas flow control devices such as valves, mass flow controllers and or metering devices (not shown) for independently controlling a plurality of inlet gas(es) 248 a and 248 b ( FIG. 16 b ) for example to each cavity/plenum 245 a , 245 b , 245 c , 245 d , 245 e , 245 f , 245 h and 245 g . The inlet gas(es) 248 a and 248 b may be reactant and or carrier gas(es). The cavity/plenum 245 a , 245 b , 245 c , 245 d , 245 e , 245 f , 245 h and 245 g can be of various width(s) 237 a , 237 b , 237 c and 237 c as shown in FIG. 16 c . The array of holes 224 a and 224 b for example, may or may not be uniform in size and spacing, in order to provide a uniform vertical flow of gas(es) 224 c and 224 d to the wafer(s) 206 on susceptor 206 from the circular segments. This vertical flow 224 c and 224 d for example may comingle with the horizontal gas flow 235 of FIG. 15 b in reactor chamber 204 a / 204 b at the surface of the wafer(s) 206 . This enables increased growth rates of the gas(es) from gas ports 225 and 226 , and or a means to separately introduce reactant gases that need to substantially combine/react only at the surface of wafer 206 to chemically vapor deposit compounds. Adjusting the flow of inlet gas(es) 248 a and 248 b can be used to vary and tune the deposition rate of the reactant gases and or those from gas ports 225 and 226 . Another feature of this embodiment is the circular upper heater assembly previously described in FIG. 14 a is positioned parallel/close to the uppermost plate 204 c . Heater sub-assemblies 140 and 160 of upper heater assemblies 100 may be associated with for example gas channel segments 245 a and 245 b together forming a controlled deposition zone (not shown) in which the temperature and flow can be independently controlled for tuning the deposition rate on the wafer 206 . An additional beneficial effect is that heaters 140 and 160 for example, preheat the inlet gas(es) 248 a and 248 b in cavity 245 a and 245 b before it arrives at the surface of wafer 206 . This minimizes the thermal impact of a cold gas on the wafer 206 and improving the reaction rate and minimizes the potential of wafer warpage that is a problem with prior art systems. Top plate 204 c may be constructed of materials such as but not limited to silicon carbide, silicon carbide coated graphite or graphite.
[0213] FIG. 16 d shows a comparison of the deposition profile across a non-rotating susceptor of a deposited layer for:
o. a prior art deposition system 250 , p. a deposition profile 251 of a deposition system 200 a as described in FIGS. 14 a , 14 b , 14 c and 14 d and FIGS. 15 a , 15 b , 15 c and 15 d herein using the heating system discussed herein and the gas injection embodiment of FIGS. 15 a , 15 b , and 15 c q. a deposition profile 252 of depositions system 200 b as described in FIG. 16 a , FIG. 16 b , FIG. 16 c . herein, the gas injections system of FIG. 15 and the vertical gas introduction technique of FIG. 16 a , FIG. 16 b and FIG. 16 c.
This deposition profile is commonly called the “depletion curve” and defines the deposition thickness across the susceptor as the reactant gases are “used-up” or depleted as they travel across the susceptor. As can be seen the technology described herein has a much more favorable depletion curve that results in a more uniform deposition across the susceptor and therefore a more uniform deposition on the wafers 206 .
[0217] Deposition systems in general all require a cleaning step for removing extraneous deposits on the internal surfaces of the reactor process chamber, the susceptor and gas inlet and exhaust conduits/ducts left behind by the deposition process. In some cases this is an insitu gas phase, high temperature cleaning step. In other cases of prior art, the cleaning step may require a complete reactor shutdown and disassembly to replace and or clean these parts. This removal and cleaning is one of the biggest reasons for reactor internal parts breakage and damage, reactor contamination and downtime. Also, the prior art system's seals may have be replaced due to damage caused by the high temperatures and exposure to deposition and etchant gases. Every time this cleaning takes place, a requalification of the process is required. This cleaning and requalification can take up to 16 hours which is lost production time. In the case of the MOCVD systems, the gas phase cleaning step of the residual deposits is ineffective and therefore the internal parts of the reactor are removed, cleaned and or replaced with new parts, which is very costly. The heating embodiment of deposition system 200 ( FIG. 14 a ), the materials of construction of the reactor chamber 204 / 204 b , the gas injections systems ( FIG. 15 a, b, c, d and FIG. 16 a, b and c ) allow for a more effective means of introducing a cleaning gases and or using different etchant/cleaning gases via 230 and 231 ( FIG. 15 e and f ) enhancing the effectiveness of the insitu gas phase cleaning (etching) of the deposits left behind thereby improving system uptime.
[0218] It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out aspects of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0219] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. | A novel heating method and a novel gas inject schemes for a depositing semiconductor layers on wafers with improved disposition uniformity and disposition composition, deposition rates and decreased depletion rates. The novel heating and gas design can be readily changed in size to accommodate the ever increasing demand for larger substrates, increased batch sizes and increased deposition and heating efficiencies. The heating scheme can operate to 1500° C., and has a high resolution capability for tuning the temperature and gas flows for easy of setup and improved control and repeatability of the deposition process. This novel heating and gas inject scheme in conjunction with the unconventional usage of a non-quartz process chamber promises higher throughputs and higher wafer yields and reduced manufacturing costs for the manufacturing of silicon devices, silicon solar cells and white High Brightness LEDs. | 2 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/811,784, filed Mar. 29, 2004, now U.S. Pat. No. 6,991,076, which is a continuation of U.S. patent application Ser. No. 09/919,582, filed Jul. 31, 2001, now U.S. Pat. No. 6,722,678, which is a continuation of U.S. patent application Ser. No. 09/288,003, filed April 6, 1999, now U.S. Pat. No. 6,267,400.
INCORPORATION BY REFERENCE
The entireties of U.S. patent application Ser. No. 10/811,784, filed Mar. 29, 2004, U.S. patent application Ser. No. 09/919,582, filed Jul. 31, 2001, and U.S. patent application Ser. No. 09/288,003, filed Apr. 6, 1999, are hereby expressly incorporated by reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of bicycle suspensions. More particularly, the invention relates to a damping enhancement system for a bicycle.
2. Description of the Related Art
For many years bicycles were constructed using exclusively rigid frame designs. These conventional bicycles relied on air-pressurized tires and a small amount of natural flexibility in the frame and front forks to absorb the bumps of the road and trail. This level of shock absorption was generally considered acceptable for bicycles which were ridden primarily on flat, well maintained roads. However, as “off-road” biking became more popular with the advent of All Terrain Bicycles (“ATBs”), improved shock absorption systems were needed to improve the smoothness of the ride over harsh terrain. As a result, new shock absorbing bicycle suspensions were developed.
Two such suspension systems are illustrated in FIGS. 1 and 2 . These two rear suspension designs are described in detail in Leitner, U.S. Pat. No. 5,678,837, and Leitner, U.S. Pat. No. 5,509,679, which are assigned to the assignee of the present application. Briefly, FIG. 1 illustrates a telescoping shock absorber 110 rigidly attached to the upper arm members 103 of the bicycle on one end and pivotally attached to the bicycle seat tube 120 at the other end (point 106 ). FIG. 2 employs another embodiment wherein a lever 205 is pivotally attached to the upper arm members 203 and the shock absorber 210 is pivotally attached to the lever 205 at an intermediate position 204 between the ends of the lever 205 .
There are several problems associated with the conventional shock absorbers employed in the foregoing rear suspension systems. One problem is that conventional shock absorbers are configured with a fixed damping rate. As such, the shock absorber can either be set “soft” for better wheel compliance to the terrain or “stiff” to minimize movement during aggressive pedaling of the rider. However, there is no mechanism in the prior art which provides for automatic adjustment of the shock absorber setting based on different terrain and/or pedaling conditions.
A second, related problem with the prior art is that conventional shock absorbers are only capable of reacting to the relative movement between the bicycle chassis and the wheel. In other words, the shock absorber itself has no way of differentiating between forces caused by the upward movement of the wheel (i.e., due to contact with the terrain) and forces caused by the downward movement of the chassis (i.e., due to movement of the rider's mass).
Thus, most shock absorbers are configured somewhere in between the “soft” and “stiff” settings (i.e., at an intermediate setting). Using a static, intermediate setting in this manner means that the “ideal” damper setting—i.e., the perfect level of stiffness for a given set of conditions—will never be fully realized. For example, a rider, when pedaling hard for maximum power and efficiency, prefers a rigid suspension whereby human energy output is vectored directly to the rotation of the rear wheel. By contrast, a rider prefers a softer suspension when riding over harsh terrain. A softer suspension setting improves the compliance of the wheel to the terrain which, in turn, improves the control by the rider.
Accordingly, what is needed is a damping system which will dynamically adjust to changes in terrain and/or pedaling conditions. What is also needed is a damping system which will provide to a “stiff” damping rate to control rider-induced suspension movement and a “soft” damping rate to absorb forces from the terrain. Finally, what is needed is a damping system which will differentiate between upward forces produced by the contact of the wheel with the terrain and downward forces produced by the movement of the rider's mass.
SUMMARY OF THE INVENTION
A bicycle shock absorber for differentiating between rider-induced forces and terrain-induced forces including a first fluid chamber having fluid contained therein. A piston is configured to compress the fluid within the fluid chamber. A second fluid chamber is coupled to the first fluid chamber by a fluid communication hose and an inertial valve is disposed within the second fluid chamber. The inertial valve is configured to open in response to terrain-induced forces and provides communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber. The inertial valve does not open in response to rider-induced forces and prevents communication of the fluid compressed by the piston from the first fluid chamber to the second fluid chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained from the following detailed description in conjunction with the following drawings, in which:
FIG. 1 illustrates a prior art rear suspension configuration for a bicycle.
FIG. 2 illustrates a prior art rear suspension configuration for a bicycle.
FIG. 3 illustrates one embodiment of the present invention.
FIG. 4 illustrates an embodiment of the present invention reacting to a rider-induced force.
FIG. 5 illustrates an embodiment of the present invention reacting to a terrain-induced force.
FIG. 6 illustrates the fluid refill mechanism of an embodiment of the present invention.
FIG. 7 illustrates another embodiment of the present invention.
FIG. 8 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted directly to an upper arm member and the remote tube is connected to an upper arm member of a bicycle. An angled position of the remote tube is shown in phantom.
FIG. 9 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted directly to an upper arm member and the remote tube and the primary tube are a single unit. An angled position of the remote tube is shown in phantom.
FIG. 10 is an enlarged schematic view of embodiment of the present invention wherein the primary tube is mounted to a lever and the remote tube is connected to an upper arm member of a bicycle. An angled position of the remote tube is shown in phantom.
FIG. 11 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted to a lever and the remote tube and the primary tube are a single unit. An angled position of the remote tube is shown in phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A damping enhancement system is described which differentiates between upward forces produced by the contact of the bicycle wheel with the terrain and downward forces produced by the movement of the rider's mass. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one of ordinary skill in the art that the present invention may be practiced without some of these specific details. In other instances, certain well-known structures are illustrated and described in limited detail to avoid obscuring the underlying principles of the present invention.
An Embodiment of the Damper Enhancement System
One embodiment of the present damper enhancement system is illustrated in FIG. 3 . The apparatus is comprised generally of a primary tube 302 and a remote tube 304 coupled via a connector hose 306 .
The damper enhancement system described hereinafter may be coupled to a bicycle in the same manner as contemporary shock absorbers (i.e., such as those illustrated in FIGS. 1 and 2 ). For example, the damper enhancement system may be coupled to a bicycle as illustrated in FIG. 1 wherein the upper mount 318 is pivotally coupled to the seat tube at point 106 and the lower mount 342 is fixedly coupled to the upper arm member 103 . Moreover, the damper enhancement system may be coupled to a bicycle as illustrated in FIG. 2 wherein the upper mount 318 is pivotally coupled to the seat tube at a point 206 and the lower mount 342 is fixedly coupled to a point 204 on lever 211 . These two constructions are illustrated in FIGS. 8-9 and FIGS. 10-11 , respectively.
In addition, depending on the particular embodiment of the damper enhancement system, the connector hose may be of varying lengths and made from varying types of material. For example, the connector hose 306 may be short and comprised of metal. In this case, the primary tube 302 and the remote tube 304 will be closely coupled together—possibly in a single unit. Such a construction is illustrated in FIG. 9 and FIG. 11 . By contrast, the connector hose may be long and comprised of a flexible material. In this case, the remote tube 304 may be separated from the primary tube 302 and may be independently connected to the bicycle (e.g., the remote tube may be connected to one of the wheel members such as upper arm member 103 in FIG. 1 ). FIG. 8 and FIG. 10 illustrate such a construction, wherein the primary tube 302 is coupled to upper arm member 103 and the remote tube 304 is connected to the upper arm member 103 by a connector. Regardless of how the remote tube 304 is situated in relation to the primary tube 302 , however, the underlying principles of the present invention will remain the same.
A piston 308 on the lower end of a piston rod 310 divides the inside of the primary tube 302 into and upper fluid chamber 312 and a lower fluid chamber 314 which are both filled with a viscous fluid such as oil. The piston rod 310 is sealed through the cap with oil seals 316 and an upper mount 318 connects the piston to the chassis or sprung weight of the bicycle (e.g., to the seat tube). A lower mount 342 connects the primary tube 302 to the rear wheel of the bicycle via one or more wheel members (e.g., upper arm members 103 in FIG. 1 or lever 205 of FIG. 2 ). Longitudinally extending passages 320 in the piston 308 provide for limited fluid communication between the upper fluid chamber 312 and lower fluid chamber 314 .
An inertial valve 322 which is slightly biased by a lightweight spring 324 moves within a chamber 326 of the remote tube 304 . The lightweight spring 324 is illustrated in a fully extended state and, as such, the inertial valve 322 is illustrated at one endmost position within its full range of motion. In this position, fluid flow from the primary tube 302 to the remote tube 304 via the connector hose 306 is blocked or reduced. By contrast, when the lightweight spring 324 is in a fully compressed state, the inertial valve resides beneath the interface between the remote tube 304 and the connector hose 306 . Accordingly, in this position, fluid flow from the primary tube 302 to the remote tube 304 through the connector hose 306 is enabled. In one embodiment, the inertial valve 322 is composed of a dense, heavy metal such as brass.
Disposed within the body of the inertial valve 322 is a fluid return chamber 336 , a first fluid return port 337 which couples the return chamber 336 to the connector hose 306 , and a second fluid return port 339 which couples the return chamber 336 to remote fluid chamber 332 . A fluid return element 338 located within the fluid return chamber 336 is biased by another lightweight spring 340 (hereinafter referred to as a “fluid return spring”). In FIG. 3 the fluid return spring 340 is illustrated in its fully extended position. In this position, the fluid return element 338 separates (i.e., decouples) the fluid return chamber 336 from the fluid return port 337 . By contrast, when the fluid return spring 340 is in its fully compressed position, the fluid return element 338 no longer separates the fluid return chamber 336 from the fluid return port 337 . Thus, in this position, fluid flow from the fluid return chamber 336 to the connector hose 306 is enabled. The operation of the inertial valve 322 and the fluid return mechanism will be described in detail below.
The remaining portion of the remote tube 304 includes a floating piston 328 which separates a gas chamber 330 and a fluid chamber 332 . In one embodiment of the present invention, the gas chamber 330 is pressurized with Nitrogen (e.g., at 150 p.s.i.) and the fluid chamber 332 is filled with oil. An air valve 334 at one end of the remote tube 322 allows for the gas chamber 330 pressure to be increased or decreased as required.
The operation of the damping enhancement system will be described first with respect to downward forces produced by the movement of the rider (and the mass of the bicycle frame) and then with respect to forces produced by the impact between the wheel and the terrain.
1. Forces Produced by the Rider
A rider-induced force is illustrated in FIG. 4 , forcing the piston arm 310 in the direction of the lower fluid chamber 314 . In order for the piston 308 to move into fluid chamber 314 in response to this force, fluid (e.g., oil) contained within the fluid chamber 314 must be displaced. This is due to the fact that fluids such as oil are not compressible. If lightweight spring 324 is in a fully extended state as shown in FIG. 4 , the inertial valve 322 will be “closed” (i.e., will block or reduce the flow of fluid from lower fluid chamber 314 through the connector hose 306 into the remote fluid chamber 332 ). Although the entire apparatus will tend to move in a downward direction in response to the rider-induced force, the inertial valve 322 will remain in the nested position shown in FIG. 4 (i.e., it is situated as far towards the top of chamber 326 as possible). Accordingly, because the fluid in fluid chamber 314 has no where to flow in response to the force, the piston 308 will not move down into fluid chamber 314 to any significant extent. As a result, a “stiff” damping rate will be produced in response to rider-induced forces (i.e., forces originating through piston rod 310 ).
2. Forces Produced by the Terrain
As illustrated in FIG. 5 , the damping enhancement system will respond in a different manner to forces originating from the terrain and transmitted through the bicycle wheel (hereinafter “terrain-induced forces”). In response to this type of force, the inertial valve 322 will move downward into chamber 326 as illustrated and will thereby allow fluid to flow from lower chamber 314 into remote chamber 332 via connector hose 306 . The reason for this is that the entire apparatus will initially move in the direction of the terrain-induced force while the inertial valve 322 will tend to remain stationary because it is comprised of a dense, heavy material (e.g., such as brass). Thus, the primary tube 302 and the remote tube 304 will both move in a generally upward direction and, relative to this motion, the inertial valve 322 will move downward into chamber 326 and compress the lightweight spring 324 . As illustrated in FIG. 5 this is the inertial valve's “open” position because it couples lower fluid chamber 314 to remote fluid chamber 332 (via connector hose 306 ).
Once the interface between connector hose 306 and remote fluid chamber 332 is unobstructed, fluid from lower fluid chamber 314 will flow across connector hose 306 into remote fluid chamber 332 in response to the downward force of piston 308 (i.e., the fluid can now be displaced). As remote fluid chamber 314 accepts additional fluid as described, floating piston 328 will move towards gas chamber 330 (in an upward direction in FIG. 5 ), thereby compressing the gas in gas chamber 330 . The end result, will be a “softer” damping rate in response to terrain-induced forces (i.e., forces originating from the wheels of the bicycle).
Once the inertial valve moves into an “open” position as described above, it will eventually need to move back into a “closed” position so that a stiff damping rate can once again be available for rider-induced forces. Thus, lightweight spring 324 will tend to move the inertial valve 322 back into its closed position. In addition, the return spring surrounding primary tube 302 (not shown) will pull piston rod 310 and piston 308 in an upward direction out of lower fluid chamber 314 . In response to the motion of piston 308 and to the compressed gas in gas chamber 330 , fluid will tend to flow from remote fluid chamber 332 back to lower fluid chamber 314 (across connector hose 306 ).
To allow fluid to flow in this direction even when inertial valve 322 is in a closed position, inertial valve 322 (as described above) includes the fluid return elements described above. Thus, as illustrated in FIG. 6 , in response to pressurized gas in gas chamber 330 , fluid in remote fluid chamber 332 will force fluid return element 338 downward into fluid return chamber 336 (against the force of the fluid return spring 340 ). Once fluid return element 338 has been forced down below fluid return port 337 , fluid will flow from remote fluid chamber 332 through fluid return port 339 , fluid return chamber 336 , fluid return port 337 , connector hose 306 , and finally back into lower fluid chamber 314 . This will occur until the pressure in remote fluid chamber 336 is low enough so that fluid return element 338 can be moved back into a “closed” position (i.e., when the force of fluid return spring 340 is greater than the force created by the fluid pressure).
The sensitivity of inertial valve 322 may be adjusted by changing the angle with which it is positioned in relation to the terrain-induced force. For example, in FIG. 5 , the inertial valve 322 is positioned such that it's movement in chamber 326 is parallel (and in the opposite direction from) to the terrain-induced force. This positioning produces the greatest sensitivity from the inertial valve 322 because the entire terrain-induced force vector is applied to the damper enhancement system in the exact opposite direction of the inertial valve's 322 line of movement.
By contrast, if the remote tube containing the inertial valve 322 were positioned at, for example, a 45 degree angle from the position shown in FIG. 5 the inertial valve's 322 sensitivity would be decreased by approximately one half because only one half of the terrain-induced force vector would be acting to move the damper enhancement system in the opposite direction of the valve's line of motion. Thus, twice the terrain-induced force would be required to trigger the same response from the inertial valve 322 in this angled configuration. FIGS. 8-11 illustrate the remote tube 304 positioned at an angle from the primary tube 302 (shown in phantom), With such a construction, the sensitivity of the inertial value 322 may be adjusted as described immediately above.
Thus, in one embodiment of the damper enhancement system the angle of the remote tube 304 in which the inertial valve 322 resides is manually adjustable to change the inertial valve 322 sensitivity. This embodiment may further include a sensitivity knob or dial for adjusting the angle of the remote tube 304 . The sensitivity knob may have a range of different sensitivity levels disposed thereon for indicating the particular level of sensitivity to which the damper apparatus is set. In one embodiment the sensitivity knob may be rotatably coupled to the bicycle frame separately from the remote tube, and may be cooperatively mated with the remote tube (e.g., with a set of gears). Numerous different configurations of the sensitivity knob and the remote tube 304 are possible within the scope of the underlying invention. The connector hose 306 of this embodiment is made from a flexible material such that the remote tube 304 can be adjusted while the primary tube remains in a static position.
Another embodiment of the damper enhancement system is illustrated in FIG. 7 . Like the previous embodiment, this embodiment includes a primary fluid chamber 702 and a remote fluid chamber 704 . A piston 706 coupled to a piston shaft 708 moves within the primary fluid chamber 702 . The primary fluid chamber 702 is coupled to the remote fluid chamber via an inlet port 714 (which transmits fluid from the primary fluid chamber 702 to the remote fluid chamber 704 ) and a separate refill port 716 (which transmits fluid from the remote fluid chamber 704 to the primary fluid chamber 702 ).
An inertial valve 710 biased by a lightweight spring 712 resides in the remote fluid chamber 704 . A floating piston 720 separates the remote fluid chamber from a gas chamber 718 . In response to terrain-induced forces (represented by force vector 735 ), the inertial valve, due to its mass, will compress the lightweight spring 712 and allow fluid to flow from primary fluid chamber 702 to remote fluid chamber 704 over inlet port 714 . This will cause floating piston 720 to compress gas within gas chamber 718 .
After inertial valve 710 has been repositioned to it's “closed” position by lightweight spring 712 , fluid in remote fluid chamber 704 will force fluid refill element 722 open (i.e., will cause fluid refill spring 724 to compress). Thus, fluid will be transmitted from remote fluid chamber 704 to primary fluid chamber 702 across refill port 716 until the pressure of the fluid in remote fluid chamber is no longer enough to keep fluid refill element 722 open. Thus, the primary difference between this embodiment and the previous embodiment is that this embodiment employs a separate refill port 716 rather than configuring a refill port within the inertial valve itself. | A bicycle shock absorber for differentiating between rider-induced forces and terrain-induced forces includes a first fluid chamber having fluid contained therein, a piston for compressing the fluid within the fluid chamber, a second fluid chamber coupled to the first fluid chamber by a fluid communication hose, and an inertial valve disposed within the second fluid chamber. The inertial valve opens in response to terrain-induced forces and provides communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber. The inertial valve does not open in response to rider-induced forces and prevents communication of the fluid compressed by the piston from the first fluid chamber to the second fluid chamber. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a charge indicating system which is capable of indicating an interruption in the power generation of a charging generator, when that interruption is caused by the disconnection of an energizing circuit or the like, by generating a voltage difference between a rectified output terminal and a storage battery and by detecting this voltage difference. The subject matter of this application is related to that of copending U.S. application Ser. No. 477,802 and 478,000, filed by the present applicants and commonly assigned.
A system according to the prior art will first be described with reference to FIG. 1. In this figure, reference numeral 1 indicates a three-phase alternating-current generator which is mounted on a vehicle (not shown) or the like and is driven by a engine (not shown). The generator 1 is constructed of three-phase star-connected armature coils 101 and a field coil 102. Numeral 2 indicates a full-wave rectifier for rectifying the a.c. output of the aforementioned generator 1. The rectifier 2 includes first and second rectified output terminals 201 and 202 and a ground terminal 203. Numeral 3 indicates a voltage regulator which is made operative to control the output voltage of the aforementioned generator to a first predetermined value by controlling the field current flowing through the aforementioned field coil 102.
In the regulator 3, numeral 301 indicates a surge absorbing diode connected with both ends of the aforementioned field coil 102. Numerals 302 and 303 indicate Darlington-connected power transistors for interrupting the current to be supplied to the aforementioned field coil 102. Numeral 304 indicates a resistor which constitutes the base circuit of the transistors 302 and 303. Numeral 305 indicates a control transistor for turning the aforementioned transistors 302 and 303 on and off. Numeral 306 indicates a Zener diode for detecting the voltage of the second rectified output terminal 202 of the aforementioned rectifier, and rendered conductive when the output voltage detected reaches the first predetermined value. Numerals 307 and 308 indicate resistors connected in series with each other to construct a voltage dividing circuit. Numeral 309 indicates an initial coil energization resistor connected in parallel with a charge indicating lamp 6, for supplying an initial energization current to the aforementioned generator 1 even if the indicating lamp 6 is disconnected. Numerals 4 and 5 indicate a storage battery and a key switch, respectively.
The operation of the prior art system thus constructed will now be described. When the key switch 5 is closed to start the engine, the transistors 302 and 303 are supplied with base current from the battery 4 through the key switch 5 and the resistor 304 so that they are rendered conductive. When the transistors 302 and 303 become conductive, the battery 4 supplies field current to the field coil 102 through the key switch 5, the charge indicating lamp 6, the resistor 309, the field coil 102 and transistors 302 and 303 so that a field magnetomotive force is generated.
When the engine is started in this state so that the generator 1 is driven, an a.c. output is induced in the armature coils 101 in accordance with the engine r.p.m. and is full-wave rectified by the full-wave rectifier 2. At this time, the rectified output is lower than the first predetermined value and the voltage at the voltage driving point of the voltage driving circuit, which is constructed of the resistors 307 and 308, is still low. As a result, the Zener diode 306 is not yet conductive but maintains its nonconductive state so that the supply of field current is maintained. As a result, the output voltage of the generator 1 is raised in accordance with the rise in generator r.p.m.
When this r.p.m. is increased such that the output voltage exceeds the aforementioned first predetermined value, the potential at the dividing point of the aforementioned voltage driving circuit is also increased to render the Zener diode 306 conductive, through which base current is supplied to the transistor 305 so that this transistor 305 is rendered conductive. When the transistor 305 becomes conductive, the transistors 302 and 302 are disconnected to interrupt the current flowing through the field coil 102, so that the output voltage of the generator 1 drops.
When the output voltage has fallen to the first predetermined value, the Zener diode 306 and the transistor 305 are rendered nonconductive, and the transistors 302 and 303 are rendered conductive to energize the field coil 102, so that the output voltage of the generator 1 is again raised.
By repeating the operations thus far described, the output voltage of the generator 1 is controlled to the aforementioned predetermined value so that the battery 4 is charged with the controlled voltage. At this time, on the other hand, the output voltage of the second rectifier output terminal 202 reaches the first predetermined value so that there is no potential difference between it and the battery 4. As a result, the charge indicating lamp 6 is turned off to indicate the charged state of the battery 4.
In the prior art system thus far described, however, if the coil energizing circuit is partially disconnected, the charge indicating lamp 6 is not lit even when the generator 1 generates no output power. This creates a defect in that this state is not detected, to invite the full discharge of the battery.
SUMMARY OF THE INVENTION
In view of the foregoing deficiencies of the prior art, the present invention contemplates the provision of a charge indicating system which eliminates these defects and indicates a non-generation state to the vehicle operator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing a generator system according to the prior art; and
FIG. 2 is a circuit diagram showing an embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in connection with one embodiment thereof with reference to FIG. 2. In FIG. 2, reference numeral 7 indicates a coil energization circuit disconnection detector which is made operative to light the aforementioned charge indicating lamp 6 by establishing a voltage difference between the second rectifier output terminal 202 and the terminal of the battery 4 when the energizing circuit is disconnected, and by detecting this voltage difference. The detector is constructed as follows.
Specifically, numeral 701 indicates a diode which has its anode connected to the charge indicating lamp 6 and its cathode connected to the second rectifier output terminal 202. Numeral 702 indicates a transistor or a switching element connected between the connection of the charge indicating lamp 6 and the diode 701 and ground. Numeral 703 indicates a resistor connected to the base of the transistor 702. Numeral 704 indicates a comparator for driving the aforementioned transistor 702 when the energizing circuit is disconnected. A comparator 705 interrupts the transistor 702 when the voltage at the second rectifier output terminal 202 is lower than a second predetermined value (during an initial energization stage). A Zener diode 706 supplies the power source voltage of the aforementioned comparators 704 and 705. Numeral 707 indicates a resistor for supplying current to the Zener diode 706. Resistors 708 and 709 are connected in series with one another to divide the voltage of the aforementioned Zener diode 706 to thereby supply the second predetermined value to the aforementioned comparator 705. Resistors 710 and 711 are connected in series to divide the voltage of the second rectifier output terminal 202 to thereby supply the divided voltage to the aforementioned comparators 704 and 705. Resistors 712 and 713 are connected in series to divide the terminal voltage of the battery 4 and supply this voltage to the energization circuit disconnection detecting comparator 704 when the key switch 5 is closed.
The operation of the system thus constructed according to the present invention will now be explained.
When the key switch 5 is closed to start the engine, the battery 4 supplies field current to the field coil 102 through the key switch 5, the charge indicating lamp 6, the diode 701, the resistor 309, the field coil 102 and the transistors 302 and 303 so that a field magnetomotive force is generated and so that the charge indicating lamp 6 is lit to indicate the non-charging state. At this time, the voltage at the second rectifier output terminal 202 is low, because the generator 1 does not yet generate power, compared to the terminal voltage at the battery 4. The voltage at terminal 202 is determined by the ratio of a composite resistance of a resistance component of the lamp 6 and the resistor 309, and the resistance component of the field coil 102. As a result, the comparator 704 is turned off to thereby turn on the transistor 702. On the contrary, the comparator 705 is turned on, because the voltage of the second rectifier output terminal 202 is below the second predetermined value, to render the transistor 702 nonconductive. As a result, the current flowing from the charge indicating lamp 6 to the field coil 102 is not shunted to the transistor, and the speed at which the a.c. generator 1 begins its generating operation is not raised so that no influence is exerted upon the generator's characteristics.
Next, when the engine is started so that the generator 1 generates an output voltage, and when the first predetermined value is obtained by control of the voltage regulator 3, little difference exists between the voltages at the second rectifier output terminal 202 and the terminal of the battery 4, so that the charge indicating lamp 6 is extinguished to indicate the charged state of the battery 4. If, in this state, an open circuit is created at the field coil 102 forming a part of the energization circuit, at the transistors 302 and 303 or in the wiring, the voltage at the second rectifier output terminal 202 becomes lower than the voltage of the battery 4 because the a.c. generator 1 generates no power. The comparator 704 is turned off by this voltage difference so that the transistor 702 is rendered conductive by the supply of base current from the base resistor 703 to thereby light the charge indicating lamp 6. In this case, the voltage at the second rectifier output terminal 202 is determined by the ratio between the series resistance of the resistors 710 and 711 and the parallel resistance of the charge indicating lamp 6 and the resistor 309.
The resistance of the resistor 711 is adjusted so that this voltage may be set at a level such as can be detected as the voltage difference from the battery terminal voltage by the comparator 704, and as higher than the second predetermined value (i.e. the rise regulating voltage) of the comparator 705. In this embodiment, moreover, comparators 704 and 705 are used. Nevertheless, similar effects can be attained a combination of a Zener diode and a transistor.
As has been described in detail hereinbefore, the system of the present invention makes use of the fact that the voltage at the second rectifier output terminal 202 is lower, when the a.c. generator 1 has its power generation interrupted as a result of a disconnection of the energization circuit, than the terminal voltage of the battery 4 by a voltage which is determined by the ratio between the series resistance of the resistors 710 and 711 and the parallel resistance of the charge indicating lamp 6 and the resistor 309. As a result, the system of the present invention lights the charge indicating lamp 6 by detecting this voltage difference by means of the comparator 704 and by driving the transistor 702. At the start of power generation of the a.c. generator 1, moreover, the second predetermined value is set as the reference voltage for the comparator 705 so that driving of the charge indicating lamp 6 by the transistor 702 may be suppressed to prevent the generator rising characteristics from being degraded. Incidentally, since comparators 704 and 705 are used for detecting the voltage difference, it is possible to detect the voltage difference highly accurately. Moreover, since the series resistance of the resistors 710 and 711 need not be set at an extremely low level, the power loss at the resistors 710 and 711 can be reduced to provide a system having little heat liberation. Thus, the present invention provides an effect such that heat liberation and the external size can be minimized by the use of a simplified system without inviting a reduction in the operating characteristics.
As has been described hereinbefore, according to the present invention, the charge indicating system is constructed to comprise a charge indicating lamp connected between the second output terminal of the rectifier and the storage battery and in series with the key switch; a diode having its anode and cathode respectively connected in series with the indicating lamp and the second rectifier output terminal; a voltage regulator for controlling the output voltage of the generator to a first predetermined value by interrupting the current supplied to the field coil; and a switching element connected between the connecting point of the charge indicating lamp and the diode and ground and adapted to be rendered conductive to light the charge indicating lamp if the voltage at the second rectifier output terminal is lower than the voltage of the storage battery but higher than a second predetermined value. Thus, the non-charging state of the generator can be indicated without fail, and the battery can be prevented from becoming discharged. | A switching element is connected between the connection point of an indicator lamp and a diode and ground and is turned on to allow battery current to pass through the lamp to light the same when it is detected that a rectifier output terminal has fallen to a voltage indicative of the lack of generator output, to thereby indicate a failure or open circuit in a coil energization circuit. | 8 |
CROSS-REFERENCE TO RELATED DOCUMENTS
[0001] The present application is a divisional application of prior co-pending patent application Ser. No. 09/747,649, filed on Dec. 22, 2000, which is a divisional application from prior application Ser. No. 09/267,953, filed on Mar. 11, 1999, now issued as U.S. 6,200,893. Priority is claimed to both cases and they are both incorporated herein in their entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention is in the area of chemical vapor deposition, and pertains more particularly to new methods and apparatus for depositing films by atomic layer deposition.
BACKGROUND OF THE INVENTION
[0003] In the manufacture of integrated circuits, deposition of thin films of many pure and compound materials is necessary, and many techniques have been developed to accomplish such depositions. In recent years the dominant technique for deposition of thin films in the art has been chemical vapor deposition (CVD), which has proven to have superior ability to provide uniform even coatings, and to coat relatively conformally into vias and over other high-aspect and uneven features in wafer topology. As device density has continued to increase and geometry has continued to become more complicated, even the superior conformal coating of CVD techniques has been challenged, and new and better techniques are needed.
[0004] The approach of a variant of CVD, Atomic Layer Deposition has been considered for improvement in uniformity and conformality, especially for low temperature deposition. However the practical implementation of this technology requires a solution to higher purity and higher throughput. This patent addresses these requirements.
[0005] Atomic Layer Deposition
[0006] In the field of CVD a process known as Atomic Layer Deposition (ALD) has emerged as a promising candidate to extend the abilities of CVD techniques, and is under rapid development by semiconductor equipment manufacturers to further improve characteristics of chemical vapor deposition. ALD is a process originally termed Atomic Layer Epitaxy, for which a competent reference is: Atomic Layer Epitaxy, edited by T. Suntola and M. Simpson, published by Blackie, Glasgo and London in 1990. This publication is incorporated herein by reference.
[0007] Generally ALD is a process wherein conventional CVD processes are divided into single-monolayer deposition steps, wherein each separate deposition step theoretically goes to saturation at a single molecular or atomic monolayer thickness, and self-terminates.
[0008] The deposition is the outcome of chemical reactions between reactive molecular precursors and the substrate. In similarity to CVD, elements composing the film are delivered as molecular precursors. The net reaction must-deposit the pure desired film and eliminate the “extra” atoms that compose the molecular precursors (ligands). In the case of CVD the molecular precursors are fed simultaneously into the CVD reactor. A substrate is kept at temperature that is optimized to promote chemical reaction between the molecular precursors concurrent with efficient desorption of byproducts. Accordingly, the reaction proceeds to deposit the desired pure film.
[0009] For ALD applications, the molecular precursors are introduced into the ALD reactor separately. This is practically done by flowing one precursor at a time, i.e. a metal precursor —ML x (M=Al, W, Ta, Si etc.) that contains a metal element—M which is bonded to atomic or molecular ligands—L to make a volatile molecule. The metal precursor reaction is typically followed by inert gas purging to eliminate this precursor from the chamber prior to the separate introduction of the other precursor. An ALD reaction will take place only if the surface is prepared to react directly with the molecular precursor. Accordingly the surface is typically prepared to include hydrogen-containing ligands—AH that are reactive with the metal precursor. Surface—molecule reactions can proceed to react with all the ligands on the surface and deposit a monolayer of the metal with its passivating ligand: substrate—AH+ML x →substrate—AML y +HL, where HL is the exchange reaction by-product. During the reaction the initial surface ligands—AH are consumed and the surface becomes covered with L ligands, that cannot further react with the metal precursor—ML x . Therefore, the reaction self-saturates when all the initial ligands are replaced with—ML y species.
[0010] After completing the metal precursor reaction the excess precursor is typically removed from the reactor prior to the introduction of another precursor. The second type of precursor is used to restore the surface reactivity towards the metal precursor, i.e. eliminating the L ligands and redepositing AH ligands.
[0011] Most ALD processes have been applied to deposit compound films. In this case the second precursor is composed of a desired (usually nonmetallic) element—A (i.e. O, N, S), and hydrogen using, for example H 2 O, NH 3 , or H 2 S. The reaction: —ML+AH z →—M—AH+HL (for the sake of simplicity the chemical reactions are not balanced) converts the surface back to be AH-covered. The desired additional element—A is deposited and the ligands L are eliminated as volatile by-product. Again, the reaction consumes the reactive sites (this time the L terminated sites) and self-saturates when the reactive sites are entirely depleted.
[0012] The sequence of surface reactions that restores the surface to the initial point is called the ALD deposition cycle. Restoration to the initial surface is the keystone of ALD. It implies that films can be layered down in equal metered sequences that are all identical in chemical kinetics, deposition per cycle, composition and thickness. Self-saturating surface reactions make ALD insensitive to transport nonuniformity either from flow engineering or surface topography (i.e. deposition into high aspect ratio structures). Non uniform flux can only result in different completion time at different areas. However, if each of the reactions is allowed to complete on the entire area, the different completion kinetics bear no penalty.
[0013] As is often the case with process development, the initial promised advantages of a new technique do not, in the end, attain their full initial promise. Unfortunately, ALD has a serious fundamental problem. Unlike CVD reactions that are of a continuous steady state nature, ALD reactions follow kinetics of molecular-surface interaction. Kinetics of molecular-surface reactions depends on the individual reaction rate between a molecular precursor and a surface reactive site and the number of available reactive sites. As the reaction proceeds to completion, the surface is converted from being reactive to non-reactive. As a result the reaction rate is slowing down during the deposition. In the simplest case the rate, dN/dt is proportional to the number of reactive sites, dN/dt=−kN, where N is the number of reactive sites and k is the (single site) reaction rate. Eliminating reactive sites (or growing of the already-reacted sites) follows an exponential time dependence kN(t)=kN 0 exp(−kt). This fundamental property of molecule-surface kinetics was named after the great scientist Langmuir, and is quite well-known in the art.
[0014] The interpretation of Langmuirian kinetics limitations illustrates a serious drawback of ALD and a severe deviation from the ideal picture.
[0015] Accordingly, the self-terminating reactions never really self-terminate (they would require an infinite time because the rate is exponentially decreasing). It means that under practical conditions the surface is never entirely reacted to completion after a deposition cycle. If the surface is not completely reacted there are leftover undesired elements in the film. For example, if the ML x reaction cannot totally consume the surface—AH sites, the film will have H incorporation. Likewise, if the AH y reaction is not carried to completion, undesired L incorporation is inevitable. Clearly, the quality of the film depends on the impurity levels. The throughput-quality tradeoff is of particular concern because it carries an exponential throughput penalty to attain a reduction of impurity levels.
[0016] In conventional atomic layer deposition one must accept low throughput to attain high-purity film, or accept lower-purity films for higher throughput. What is clearly needed is an apparatus and methods which not only overcome the Langmuirian limitations but simultaneously provide higher-purity films than have been available in the prior art methods. Such apparatus and methods are provided in embodiments of the present invention, taught in enabling detail below.
SUMMARY OF THE INVENTION
[0017] In a preferred embodiment of the present invention a method for depositing a metal on a substrate surface in a deposition chamber is provided, comprising steps of (a) depositing a monolayer of metal on the substrate surface by flowing a molecular precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing at least one radical species into the chamber and over the surface, the radical species highly reactive with the surface ligands of the metal precursor layer and eliminating the ligands as reaction product, and also saturating the surface, providing the first reactive species; and (e) repeating the steps in order until a metallic film of desired thickness results.
[0018] In many such embodiments the radical species is atomic hydrogen. Using atomic hydrogen a broad variety of pure metals may be deposited, such as tungsten, tantalum, aluminum, titanium, molybdenum, zinc, hafnium, niobium and copper.
[0019] In another aspect of the invention a method is provided for depositing a metal oxide on a substrate surface in a deposition chamber, comprising steps of (a) depositing a monolayer of metal on the substrate surface by flowing a metal molecular precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the radical species highly reactive with the reaction product and combining with the reaction product to create volatile species and saturate the surface with the first radical species; (e) flowing radical oxygen into the chamber to combine with the metal monolayer deposited in step (a), forming an oxide of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.
[0020] In this method the first and third radical species may be both atomic hydrogen, and the metal surface in step (f) is terminated with hydroxyl species reactive with the metal precursor to deposit the metal. In another embodiment the oxygen and hydrogen atomic steps (e) and (f) are repeated to improve film quality. In still another embodiment steps (e) and (f) are combined into one step wherein the surface is reacted with hydrogen and oxygen atoms simultaneously.
[0021] In various embodiments for depositing oxides the oxides can be tantalum pentoxide, aluminum oxide, titanium oxide, niobium pentoxide, zirconium oxide, hafnium oxide, zinc oxide, molybdenum oxide, manganese oxide, tin oxide, indium oxide, tungsten oxide and silicon oxide, among others.
[0022] In some embodiments the first radical species is atomic hydrogen and steps (e) and (f) are united to one step using OH radicals, and the metal surface in step (f) is terminated with hydroxyl species reactive with the metal precursor to deposit the metal.
[0023] In still another aspect of the invention a method for depositing a metal nitride on a substrate surface in a deposition chamber is provided, comprising steps of (a) depositing a monolayer of metal on the substrate surface by flowing a metal precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the atomic species highly reactive with the surface ligands of the metal precursor layer and eliminating the ligands as reaction product and also saturating the surface; (e) flowing radical nitrogen into the chamber to combine with the metal monolayer deposited in step (a), forming a nitride of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.
[0024] In this method the first and third atomic radical species may both be atomic hydrogen, and the metal surface in step (f) may be terminated with amine species reactive with the metal precursor to deposit the metal. Further, steps (e) and (f) may be combined into one step wherein the surface is reacted with hydrogen and nitrogen atoms simultaneously.
[0025] In variations of this embodiment a variety of different nitrides may be produces, including, but limited to tungsten nitride, tantalum nitride, aluminum nitride, titanium nitride, silicon nitride and gallium nitride.
[0026] In another variation the first radical species may be atomic hydrogen and steps (e) and (f) may be united into one step using one or both of NH and NH 2 radicals, and the metal surface in step (f) is terminated with amine species reactive with the metal precursor to deposit the metal.
[0027] In yet another aspect of the invention a process for building a metal, metal oxide, or metal nitride film on a substrate surface is provided, wherein deposition steps comprise flowing a metal precursor gas or vapor over the surface with the surface terminated with a first chemical species reactive with the metal precursor to deposit the metal, are alternated with steps comprising flowing radical species over the freshly deposited metal layers to remove the ligands from the deposition steps and to provide the first chemical species to terminate the substrate surface preparatory to the next deposition reaction.
[0028] In this process a metal nitride film is built up by a step sequence of metal deposition by reacting a metal precursor gas with a surface terminated by amine species, then alternating exposure of the surface with atomic radical hydrogen, nitrogen and hydrogen again, thereby volatilizing products remaining from the metal deposition chemistry, nitridizing the deposited metal monolayer, then terminating the metal surface with amine species again in preparation for a next metal deposition step. A metal oxide film is built up by a step sequence of metal deposition by reacting a metal precursor gas with a surface terminated by hydroxyl species, then alternating exposure of the surface with atomic radical hydrogen, oxygen and hydrogen again, thereby volatilizing products remaining from the metal deposition chemistry, oxidizing the metal monolayer, then terminating the metal surface with hydroxyl species again in preparation for a next metal deposition step.
[0029] In yet another aspect of the invention a method for depositing a compound film on a substrate surface in a deposition chamber is provided, comprising steps of (a) depositing a monolayer of metal on the substrate surface by flowing a metal molecular precursor gas or vapor bearing the metal over a surface of the substrate, the surface saturated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface covered with ligands from the metal precursor and therefore not further reactive with the precursor; (b) terminating flow of the precursor gas or vapor; (c) purging the precursor with inert gas; (d) flowing a first radical species into the chamber and over the surface, the radical species highly reactive with the reaction product and combining with the reaction product to create volatile species and saturate the surface with the first radical species; (e) flowing nonmetal atomic species into the chamber to combine with the metal monolayer deposited in step (a), forming a compound film of the metal; (f) flowing a third radical species into the chamber terminating the surface with the first reactive species in preparation for a next metal deposition step; and (g) repeating the steps in order until a composite film of desired thickness results.
[0030] In this method the first and third radical species may be both atomic hydrogen, and the metal surface in step (f) is terminated with hydride species of the nonmetallic element that are reactive with the metal precursor to deposit the metal. In a variation the non-metallic and hydrogen atomic steps (e) and (f) are repeated to improve the film quality. In another variation steps (e) and (f) are combined into one step wherein the surface is reacted with hydrogen and non-metallic atoms simultaneously. A variety of films may be produced by practicing this variation of the invention as well, including but not limited to molybdenum disulfide and zinc sulfide.
[0031] In yet another aspect of the invention a radical-assisted sequential CVD (RAS-CVD) reactor is provided, comprising a chamber with controlled gas inlets for introducing gases in sequential steps and a heated substrate support for holding a substrate and exposing a surface of the substrate to incoming gases; and a plasma generation apparatus for generating radical atomic species for use in the reactor. In this reactor an aggregate metal layer is formed by depositing a monolayer of metal on the substrate surface by flowing a precursor gas or vapor bearing the metal over a surface of the substrate, the surface terminated by a first reactive species with which the precursor will react by depositing the metal and forming reaction product, leaving a metal surface not further reactive with the precursor, terminating flow of the precursor gas or vapor, flowing at least one atomic radical species into the chamber and over the surface, the atomic species highly reactive with the reaction product and combining with the reaction product, and also terminating the surface, providing the first reactive species, and repeating the steps in order until a composite film of desired thickness results.
[0032] In various embodiments the atomic radical species is atomic hydrogen. The precursor gas bearing the metal may be tungsten hexafluoride and the metal deposited tungsten.
[0033] In some embodiments the plasma generation apparatus comprises an electrode within the reactor chamber and a high frequency power supply connected to the electrode. In other embodiments the plasma generation apparatus comprises a showerhead-type gas distribution apparatus, and a plasma is generated within the showerhead apparatus to produce the radical species. In still other embodiments the atomic radical species is produced in a remote plasma generator, and the species are delivered to the reactor.
[0034] In the various embodiments of the invention a new process is provided wherein films of many sorts, including pure metals, oxides of metals, nitrides of metals, and other films, may be produced quickly and efficiently, with very high purity and with superior conformity to substrate topography and coverage within vias and other difficult surface geometries.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] [0035]FIG. 1 is a generalized diagram of a reactor and associated apparatus for practicing a radical-assisted sequential CVD process according to an embodiment of the present invention.
[0036] [0036]FIG. 2 is a step diagram illustrating the essential steps of an atomic layer deposition process.
[0037] [0037]FIG. 3 is a step diagram illustrating steps in a radical-assisted CVD process according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] The inventor has developed an enhanced variation of ALD which alters the conventional surface preparation steps of ALD and overcomes the problems of conventional ALD, producing high throughput without compromising quality. The inventor terms the new and unique process Radical-Assisted Sequential CVD (RAS-CVD).
[0039] [0039]FIG. 1 is a generalized diagram of a system 11 for practicing RAS-CVD according to an embodiment of the present invention. In this exemplary system a deposition chamber 13 has a heatable hearth for supporting and heating a substrate 19 to be coated, and a gas distribution apparatus, such as a showerhead 15 , for delivering gaseous species to the substrate surface to be coated. Substrates are introduced and removed from chamber 13 via a valve 21 and substrate-handling apparatus not shown. Gases are supplied from a gas sourcing and pulsing apparatus 23 , which includes metering and valving apparatus for sequentially providing gaseous materials. An optional treatment apparatus 25 is provided for producing gas radicals from gases supplied from apparatus 23 .
[0040] The term radicals is well-known and understood in the art, but will be qualified again here to avoid confusion. By a radical is meant an unstable species. For example, oxygen is stable in diatomic form, and exists principally in nature in this form. Diatomic oxygen may, however, be caused to split to monatomic form, or to combine with another atom to produce ozone, a molecule with three atoms. Both monatomic oxygen and ozone are radical forms of oxygen, and are more reactive than diatomic oxygen. In many cases in embodiments of the present invention the radicals produced and used are single atom forms of various gases, such as oxygen, hydrogen, and nitrogen, although the invention is not strictly limited to monatomic gases.
[0041] [0041]FIG. 2 is a step diagram of a conventional Atomic Layer Deposition process, and is presented here as contrast and context for the present invention. In conventional ALD, as shown in FIG. 2, in step 31 a first molecular precursor is pulsed in to a reactor chamber, and reacts with the surface to produce (theoretically) a monolayer of a desired material. Often in these processes the precursor is a metal-bearing gas, and the material deposited is the metal; Tantalum from TaCl 5 , for example.
[0042] In step 33 in the conventional process an inert gas is pulsed into the reactor chamber to sweep excess first precursor from the chamber.
[0043] In step 35 in the conventional system a second precursor, typically non-metallic, is pulsed into the reactor. The primary purpose of this second precursor is to condition the substrate surface back toward reactivity with the first precursor. In many cases the second precursor also provides material from the molecular gas to combine with metal at the surface, forming compounds such as an oxide or a nitride with the freshly-deposited metal.
[0044] At step 37 the reactor chamber is purged again to remove excess of the second precursor, and then step 31 is repeated. The cycle is repeated as many times as is necessary to establish a desired film.
[0045] [0045]FIG. 3 is a step diagram illustrating steps in a radical-assisted CVD process according to an embodiment of the present invention. In the unique process illustrated by FIG. 3 the first steps, steps 41 and 43 , are the same as in the conventional process. A first precursor is pulsed in step 41 to react with the substrate surface forming a monolayer of deposit, and the chamber is purges in step 43 . The next step is unique. In step 45 single or multiple radical species are pulsed to the substrate surface to optionally provide second material to the surface and to condition the surface toward reactivity with the first molecular precursor in a subsequent step. Then step 41 is repeated. There is no need for a second purge, and the cycle is repeated as often as necessary to accomplish the desired film.
[0046] Step 45 may be a single step involving a single radical species. For example, the first precursor may deposit a metal, such as in W from WF 6 , and the radical species in step 45 may be atomic hydrogen. The atomic hydrogen very quickly and effectively neutralizes any remaining F to HF, and terminates the surface with atomic hydrogen, providing reactive surface for the next pulse of WF 6 .
[0047] In many cases step 45 will be a compound step comprising substeps involving different radical species. A good example is a sequence of atomic hydrogen followed by atomic oxygen, followed by atomic hydrogen again. The first hydrogen step neutralizes Cl or other remaining ligand, the atomic oxygen provides an oxide of the freshly-deposited metal, and the second atomic hydrogen terminated the surface with (OH) in preparation for the next metal precursor step.
[0048] There are a broad variety of materials and combinations in step 45 , and many are disclosed in more detail below, along with a more complete explanation of process chemistry.
[0049] In RAS-CVD, following the metal precursor reaction, highly reactive radical species are introduced to quickly react with products of the metal precursor reaction and to prepare the surface for the next metal precursor reaction. Radical species, as introduced above, are reactive atoms or molecular fragments that are chemically unstable and therefore are extremely reactive. In addition, radicals chemisorb to surfaces with virtually 100% efficiency. Radicals may be created in a number of ways, and plasma generation has been found to be an efficient and compatible means of preparation.
[0050] RAS-CVD processes use only a single molecular precursor, in many cases a metal precursor. Surface preparation as well as the deposition of nonmetallic elements are accomplished by atom-surface reactions. Following the metal precursor reaction, The —ML terminated surface is reacted with hydrogen atoms to convert the surface into -MH and eliminate HL by-product. Unlike molecule-surface reactions, atom-surface reactions do not depend on the number density of reactive sites: Most atoms (except for noble gases) stick very efficiently to surfaces in an irreversible process because atomic desorption is usually unfavorable. The atoms are highly mobile on non-reactive sites and very reactive at reactive sites. Consequently, atom-surface reactions have linear exposure dependence, as well as high rates.
[0051] The —MH surface can be reacted with A atoms to yield a —M—A surface. In this case some of the H ligands can be eliminated as AH y . For example the —MH surface can be reacted with oxygen atoms to deposit oxide compound. Alternatively, —MH surface can be reacted again with ML x for atomic layer controlled deposition of M metal films. For the deposition of nitride compound films, A is atomic nitrogen. The surface after the A atomic reaction is terminated with A— and AH. At this point an additional atomic reaction with hydrogen converts the surface to the desired AH ligands that are reactive towards the metal precursor. Alternatively, the MH surface can be reacted with a mixture of A and H atoms to convert the surface into —AH terminated surface with one less step. All the above described reactions are radical-surface reactions that are fast and efficient and depend linearly on exposure. In addition, the final hydrogen reaction results in a complete restoration to the initial surface without any incorporation of impurities.
[0052] Another throughput benefit of RAS-CVD is that a single purge step after the metal precursor step is needed, rather than the two purge steps needed in the conventional process. Purge steps are expected by most researchers to be the most significant throughput-limiting step in ALD processes. Another advantage is that RAS-CVD promises longer system uptime and reduced maintenance. This is because atomic species can be efficiently quenched on aluminum walls of the deposition module. Downstream deposition on the chamber and pumping lines is therefore virtually eliminated. RAS-CVD eliminates the use of H 2 O and NH 3 that are commonly applied for oxides and nitrides deposition (respectively) in the prior art. These precursors are notorious to increase maintenance and downtime of vacuum systems.
[0053] According to the above a typical RAS-CVD cycle for a metal oxide film will comprise steps as follows:
[0054] 1. Metal precursor reaction with —OH (hydroxyl) terminated surface to attach —O—ML y and eliminate the hydrogen by HL desorption. The surface becomes covered with L ligands, i.e. in the case of TaCl 5 the surface becomes covered with Cl atoms.
[0055] 2. Purge with inert gas to sweep away excess metal precursor.
[0056] 3. Atomic hydrogen step—eliminates the ligands L by HL desorption and terminates the surface with hydrogen.
[0057] 4. Atomic oxygen step—reacts with monolayer of metal to form oxide. Atomic hydrogen again to leave hydroxyl saturated surface for next metal precursor step.
[0058] At this point the quality of oxide films (i.e. insulation properties, dielectric strength, charge trapping) can be improved by running steps 4+5 for multiple times. For example: Al 2 O 3 RAS-CVD can be realized from trimethylaluminum Al(CH 3 ) 3 , hydrogen and oxygen exposures. Al(CH 3 ) 3 reacting with —OH terminated surface will deposit —OAl(CH 3 ) x concurrent with the desorption of methane (CH 4 ). The —OAl(CH 3 ) x (x=1, 2) surface will be treated with H atoms to eliminate x number of methane molecules and terminate the surface with —OAlH. This surface after consecutive (or concurrent) reaction with O atoms and H atoms will be terminated OAl—OH which is the restoration state. At this point, the RAS-CVD process can proceed by applying another Al(CH 3 ) 3 reaction. Alternatively, the —OAl—OH surface can be exposed to another cycles of O and H atomis. At temperature above 100° C. this process will exchange OH groups and Al—O—Al bridge sites and the resulted —OAl—OH surface will be more thermodynamically favorable than the beginning surface, because the process eliminates the more strained (Al—O—) n ring structures as well as titrating away defects and broken bonds). Since the atomic reactions are rather fast, these quality improvements are not expected to be a major throughput concern. In fact, ultimate quality may be achieved by applying the O, H cycles for several times. Following, a given number of O, H atomic reactions the sequence will continue with the next Al(CH 3 ) 3 reaction.
[0059] 6. Repeat steps from 1.
[0060] For metal nitrides atomic nitrogen is substituted for oxygen. For pure metal depositions the oxygen/nitrogen step may be eliminated in favor of a single atomic hydrogen step, such as for tungsten films. The hydrogen saturated surface after the first atomic hydrogen step is reactive with WF 6 to produce the pure metal.
[0061] The generic nature of RAS-CVD is advantageous for multiple layer combination films of different oxides, different nitrides, oxides with nitrides, different metals and metals with compound films.
[0062] In another unique process, useful for barrier layers, the WN process may be combined with the pure W process to produce alternating W and WN layers in a variety of schemes to suppress polycrystallization and to reduce the resistivity of the barrier layer. Other properties, such as electromigration may be controlled by an ability to provide a graded layer of WN with reduced nitrogen content at the copper interface for such applications.
[0063] In embodiments of the invention a broad variety of process chemistries may be practiced, providing a broad variety of final films. In the area of pure metals, for example, the following provides a partial, but not limiting list:
[0064] 1. Tungsten from tungsten hexafluoride.
[0065] 2. Tantalum from tantalum pentachloride.
[0066] 3. Aluminum from either aluminum trichloride or trimethylaluminum.
[0067] 4. Titanium from titanium tetrachloride or titanium tetraiodide.
[0068] 5. Molybdenum from molybdenum hexafluoride.
[0069] 6. Zinc from zinc dichloride.
[0070] 7. Hafnium from hafnium tetrachloride.
[0071] 8. Niobium from niobium pentachloride.
[0072] 9. Copper from Cu 3 Cl 3
[0073] In the area of oxides the following is a partial but not limiting list:
[0074] 1. Tantalum pentoxide from tantalum pentachloride.
[0075] 2. Aluminum oxide from trimethylaluminum or aluminum trichloride.
[0076] 3. Titanium oxide from titanium tetrachloride or titanium tetraiodide.
[0077] 4. Niobium pentoxide from niobium pentachloride.
[0078] 5. Zirconium oxide from zirconium tetrachloride.
[0079] 6. Hafnium oxide from hafnium tetrachloride.
[0080] 7. Zinc oxide from zinc dichloride.
[0081] 8. Molybdenum oxide from molybdenum hexafluoride or molybdenum pentachloride.
[0082] 9. Manganese oxide from manganese dichloride.
[0083] 10. Tin oxide from tin tetrachloride.
[0084] 11. Indium oxide from indium trichloride or trimethylindium.
[0085] 12. Tungsten oxide from tungsten hexafluoride.
[0086] 13. Silicon dioxide from silicon tetrachloride.
[0087] In the area of nitrides, the following is a partial but not limiting list:
[0088] 1. Tungsten nitride from tungsten hexafluoride.
[0089] 2. Tantalum nitride from tantalum pentachloride.
[0090] 3. Aluminum nitride from aluminum trichloride or trimethylaluminum.
[0091] 4. Titanium nitride from titanium tetrachloride.
[0092] 5. Silicon nitride from silicon tetrachloride or diehlorosilane.
[0093] 6. Gallium nitride from trimethylgallium.
[0094] Hardware Requirements
[0095] Another advantage of RAS-CVD is that it is compatible in most cases with ALD process hardware. The significant difference is in production of atomic species and/or other radicals, and in the timing and sequence of gases to the process chamber. Production of the atomic species can be done in several ways, such as (1) in-situ plasma generation, (2) intra-showerhead plasma generation, and (3) external generation by a high-density remote plasma source or by other means such as UV dissociation or dissociation of metastable molecules, referring again to FIG. 1, these methods and apparatus are collectively represented by apparatus 25 .
[0096] Of the options, in-situ generation is the simplest design, but poses several problems, such as turn on—turn off times that could be a throughput limitation. Intra-showerhead generation has been shown to have an advantage of separating the atomic specie generation from the ALD space. The preferable method at the time of this specification is remote generation by a high-density source, as this is the most versatile method. The radicals are generated in a remote source and delivered to the ALD volume, distributed by a showerhead over the wafer in process.
[0097] It will be apparent to the skilled artisan that there are a variety of options that may be exercised within the scope of this invention as variations of the embodiments described above some have already been described. For example, radicals of the needed species, such as hydrogen, oxygen, nitrogen, may be generated in several ways and delivered in the process steps. Further, ALD chambers, gas distribution, valving, timing and the like may vary in many particulars. Still further, many metals, oxides nitrides and the like may be produced, and process steps may be altered and interleaved to create graded and alternating films.
[0098] In addition to these variations it will be apparent to the skilled artisan that one may, by incorporating processes described herein, alternate process steps in a manner that alloys of two, three or more metals may be deposited, compounds may be deposited with two, three or more constituents, and such things as graded films and nano-laminates may be produced as well. These variations are simply variants using particular embodiments of the invention in alternating cycles, typically in-situ. There are many other variations within the spirit and scope of the invention, so the invention is limited only by the claims that follow. | A new method for CVD deposition on a substrate is taught wherein radical species are used in alternate steps to depositions from a molecular precursor to treat the material deposited from the molecular precursor and to prepare the substrate surface with a reactive chemical in preparation for the next molecular precursor step. By repetitive cycles a composite integrated film is produced. In a preferred embodiment the depositions from the molecular precursor are metals, and the radicals in the alternate steps are used to remove ligands left from the metal precursor reactions, and to oxidize or nitridize the metal surface in subsequent layers. A variety of alternative chemistries are taught for different films, and hardware combinations to practice the invention are taught as well. | 7 |
This invention relates to decorative ribbons, and to methods and machines for making them. More specifically, the invention relates to fabric ribbons that are edged with wire and trimmed with an overlay of decorative thread.
According to the invention, a run of fabric ribbon is simultaneously edged with wire and tightly bound with a binding filament (such as monofilament) and a trim filament (such as decorative thread). This is done in a single operation. The result is a unique ribbon construction, which has many desirable properties. The new ribbons are flexible, but will retain their shape when bent, twisted or tied into a desired configuration. They are elegantly simple in design and provide a novel streamlined finished product with components that are firmly bound together. The ribbons provide an improved edge and trimming where the wire meets the fabric. They represent an improvement in strength and design, by conveniently providing a two-sided edged ribbon rather than a one-sided edged ribbon having a definite front side and back side. These and other advantages and objectives will become apparent from the detailed description of the invention below.
BACKGROUND OF THE INVENTION
Decorative fabric ribbons are known, as are fabric ribbons that have been edged with wire. However, the prior art wire ribbons are made by laying a wire near the edge of a fabric ribbon, folding the edge of the ribbon over the wire, and sewing or gluing down the folded edge to hold the wire in place.
This type of construction provides a ribbon that will retain its shape when bent, but which suffers from several significant disadvantages.
The folded edge in these known ribbons produces an unsightly seam, which gives the ribbon a definite front and a back, and which makes it more difficult to fashion the ribbon into pleasing shapes.
When the fabric edge is sewn down, the wire is only loosely held within a fabric sleeve, and thus it can move apart from the ribbon. This makes it more difficult to shape the ribbon, and a sliding wire can result in excess wire at one end of the ribbon and no wire at the other end. The sliding wire also makes the ribbon more difficult to control, and the ribbon is less likely to retain its shape over time. Side to side slippage of the wire can also cause undesirable bunching and/or buckling of the fabric.
Similar problems arise when glue is used. Although some glues may help keep the wire firmly in place, in general the bond is weak and cannot withstand the stress of normal use. Thus, the wire will eventually separate from the glue and ribbon over time, or when the ribbon is bent, twisted or tied in use. In addition, the application of the glue and the removal of excess glue results in significant production and quality control problems. For example, excess glue can deface the fabric ribbon, and glues of sufficient strength to hold the wire in place can degrade the fabric.
Another known method involves loosely sealing a wire between two laminated and/or embossed surfaces, which disadvantageously requires the use of two independent fabric surfaces. These ribbons typically are bulky and have an unsightly rear face. Additionally, the two surfaces have a tendency to separate, which defeats the purpose of having a reliable wired ribbon.
In view of these disadvantages, there has been a need for an improved decorative wired ribbon, especially one that provides a firm and integral union of fabric and wire, without the undesirable folds, seams and glue of prior ribbons.
Accordingly, it is an object of this invention to overcome the disadvantages of known wired ribbons, by providing a fabric ribbon edged with wire and bound with trim, so that the wire is hidden from view and yet is firmly affixed to the ribbon without folds, seams or glue.
It is another object of the invention to provide a method of making ribbons edged with wire and bound with trim.
It is yet another objective to provide an apparatus for making the ribbons of the invention.
SUMMARY OF THE INVENTION
The decorative ribbon of the invention comprises a fabric ribbon, a wire filament, at least one decorative or trim filament, and at least one binding filament. The trim and wire filaments are firmly bound and affixed to the fabric by the binding filament. In a preferred embodiment, this is achieved in one simultaneous and continuous operation. Also, the binding filament is preferably chosen and the trim filament is applied in a size, quantity and manner such that the wire filament and binding filament are both substantially or even completely hidden by the trim filament. This provides a seamless stitched border in one operation that holds the wire filament in place without slippage, and without intermediate folding, gluing, embossing or laminating steps.
The ribbon can be any known fabric ribbon, either flat or pleated. It has been found however that certain lighter weight flat fabrics should be sized, to provide added stiffness, while pleated fabrics generally do not benefit from sizing because the heat treatment used to pleat the fabrics generally increases the stiffness anyway. As the width of the fabric ribbon is increased, the need for sizing also increases, especially in sheer or flimsy fabrics. Any known sizing can be used, such as spray starch, and skilled practitioners can readily determine without undue experimentation whether a particular fabric should be sized in connection with the decorative ribbons of the invention. Other fabric finishes can also be used, as desired.
Preferred finished ribbon sizes according to the invention are widths of 1 7/16 (#9), 2 3/4 (#40), 4 (#100), 6, and 10 inches.
Pleated fabrics can be obtained from flat fabrics, for use in this invention, according to known means of pleating or texturing fabrics. Typically, a flat fabric is run through a pleating machine that is provided with knives. The fabric is scored with the knives, to produce the textured or pleated effect, which is preserved by heat treating the scored fabric to a temperature of about 250°-300° F. The pleated fabric is sandwiched between holding paper and rolled for storage, so that the pleats retain their shape without damage.
The wire filament can be any flexible filament that will hold its shape without breaking when bent or twisted. The preferred wire filament of the invention is galvanized steel, which can range in gauge from about 22 to 32. The wire filament should be both strong and light, and the most suitable compromise according to the invention, for ribbons ranging in width from 2 to 7 inches, is gauge 26 galvanized steel wire.
The trim filament of the invention can be any known decorative thread of a suitable strength and thickness, which can be wound around the wire filament and through the fabric on a needle, without breaking or snagging, and with enough weight and body to substantially or completely cover the wire filament. Metallic threads are particularly suitable, especially those comprising a metallic strand wrapped with one or two nylon strands. It has been found that a metallic strand that is 1/69th of an inch thick (about 150 gauge) that is wrapped with one, preferably two strands of 70 denier nylon strands is especially preferred. Non-metallic threads can also be used. According to the invention, threads ranging in thickness from 1/100th to 1/50th of an inch, and wrapped with one or two strands (or ends) of nylon ranging from 50 to 90 denier can be used.
The binding filament can be any filament chosen for strength and light weight, and preferably is one strand of monofilament ranging in thickness from 0.005 mil. to 0.009 mil. The preferred monofilament is 0.007 mil. in thickness.
The novel decorative ribbon of the invention is made by binding the wire filament and the trim filament to the fabric ribbon with the binding filament in one operation that both fixes the wire to the edge of the fabric, and hides the wire from view by covering it with turns of trim filament. This is done on a feed-driven stitching machine that is specially modified according to the invention, as further described below. Thus, the stitching machine supplies the fabric ribbon with a co-extensive length of wire filament that is simultaneously bound to the fabric by the binding filament and covered over by the trim filament.
The invention and specific examples and embodiments thereof are further described in connection with the following drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art ribbon with the edge of the ribbon folded over the wire to form a sleeve and seam.
FIG. 2 shows the underside of a decorative ribbon according to the invention with a wire bound to the edge of the fabric and covered over with trim.
FIG. 3 shows a side view of an apparatus according to the invention.
FIG. 4 shows an enlarged top view of a portion of FIG. 3, showing a needle plate according to the invention.
FIG. 5 shows an enlarged bottom view of a portion of FIG. 3, showing a needle plate according to the invention.
FIG. 6 shows an enlarged side view of a portion of FIG. 3, showing a needle plate according to the invention.
FIG. 7 shows a representative decorative ribbon according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2, there is shown a portion of a decorative ribbon including an edge wire secured according to the present invention. The ribbon material 10 includes an actual edge 11 and a side edge 12. In this particular embodiment, a galvanized steel wire filament 14 is positioned along the actual edge 11 of the ribbon material 10 and is surrounded by a smooth fold created by the side edge 12. The ribbon material 10 is secured to the wire filament 14 by a sewing stitch, such as the purl stitch shown. In this embodiment, the stitch includes two filaments, a decorative trim filament 18 and a binding filament 20.
The purpose of the trim filament 18 is to substantially or entirely cover the wire filament 14, the side edge 12 and the actual edge 11, thereby providing a clean, continuous and decorative edge to the ribbon material 10. This can be achieved, as shown, by positioning the trim filament 18 in a curved serpentine fashion around both the wire filament 14 and the side edge 12 of the ribbon material 10. The serpentine shape of the trim filament includes loops 22.
During the stitching process, the binding filament 20 pierces the ribbon material 10 and inter-weaves through the serpentine loops 22 of the trim filament 18. The binding filament 20 is kept taut during the stitching process, and the trim filament 18 and the interposed edge portion of the ribbon are pulled into engagement with the inner wire filament 14. In this way, the decorative trim filament 18 becomes substantially wrapped around the otherwise exposed side edge 12 and the actual edge 11 of the ribbon material 10, all of which are securely bound together by the binding filament 20. Thus, the tight stitch created by the binding and trim filaments, acting together, secures the wire filament 14 to the ribbon material 10. In a preferred embodiment, the binding filament is a natural monofilament, chosen for its strength and also because it is effectively invisible. This allows the trim filament to be seen, so that the ribbon is provided with a securely wired and decorative edge.
Thus, according to the invention, resulting decorative ribbon product provides a tightly secured hidden wire filament 14 along each edge of the ribbon material to support the ribbon's shape, and a decoratively disguised stitch that permits dual-side ribbon applications.
FIG. 7 shows a portion of a finished ribbon product having the edge wire arrangement of the present invention. As shown, both sides of the ribbon have an even and clean appearance showing no ribbon edge material.
In contrast to the invention, FIG. 1 shows a typical prior art wire-edged ribbon which includes an exposed securing stitch and actual ribbon edge.
In this figure, a wire 100 is surrounded by a fold 102 created along the actual edge 103 of ribbon material 104. The fold 102 is secured flat against the underside (topside as shown in FIG. 1) of the ribbon material 104, near the actual edge 103 using a conventional straight stitch 106. Since no tight frictional force has been applied to the enclosed wire 100, the wire is free to move laterally which could cause the straight stitch 106 to loosen. The wire arrangement shown in FIG. 1 can also move linearly (in a direction parallel to the ribbon edge) which could cause the wire 100 to become completely detached from within the fold 102. In either case, the straight stitch 106 and the actual ribbon edge 103 are in full view along the under side of the ribbon material 104. The resulting finished decorative ribbon product is therefore limited to one-side applications, and has a much less desirable non-uniform appearance. It also suffers from weaknesses in construction that the invention has overcome.
The present invention also provides an improved adaptation to a conventional high speed stitching machine to create the secured wire ribbon-edge arrangement of the present invention. Two examples of such a machine are the Merrow High Speed Trimming & Overseaming Machine (class M) manufactured by the Merrow Company of Hartford, Conn., and the Pegasus S32 manufactured by the Pegasus Sewing Machine Manufacturing Co., Ltd. of Osaka, Japan.
The stitching machine 30 is shown in FIG. 3, adjacent to guide rollers 32 and includes a work plate 34 for supporting the ribbon material 10, a moveable sewing needle 36, a feed carrier 38 for feeding the ribbon material 10 and a needle plate 40 which is typically recessed into and coplanar with the work plate 34.
The guide rollers 32 are preferably power driven using conventional methods so that the ribbon material 10 is drawn from the work plate 34 of the stitching machine 30 in time with the stitching operation. The purpose of the rollers 32 is to maintain tension in (prevent buckling) the ribbon material 10 during and after it has been stitched. If the ribbon material 10 is not pulled from the stitching machine 30, the stitch can become distorted or otherwise uneven and unattractive and the various elements of the invention (ribbon, wire and filaments) will not be secured in a satisfactory manner.
The drive speed of the rollers 32 is dictated by the feed rate established by the internal feed carrier 38 (not shown in detail), typically protruding from within the needle plate 40. The feed carrier 38 pulls the ribbon material 10 from a supply roll (not shown). It is conventionally known that the drive speed of the guide rollers 32 and the feed rate of the feed carrier 38 should be matched during high speed edge stitching so that the ribbon material 10 can be drawn from the supply roll, stitched, and drawn to a collection roll (also not shown) in a smooth flow.
As understood in the stitching industry, a typical edge stitch comprises two filaments of thread. One thread is usually supplied to the fabric (in this case to the ribbon material 10) by "loopers" from below the needle plate 40 (not shown), while the other thread is fed to the needle 36 usually above the needle plate 40. In the present invention, the first thread (below the needle plate 40) is preferably the trim filament 14 and the second thread (fed to the needle above the needle plate 40) is preferably the binding filament 20. The normal operation of the stitching machine 30 provides a conventional stitch by interweaving the binding filament 20 with the trim filament 18, as further described below.
By the present invention, a wire filament 14 is provided within the fold of the side edge 12 of the ribbon material 10, before the stitch is produced by the stitching machine 30. It is desireable to form the side edge 12 of the ribbon material around the wire filament 14 immediately prior to the stitch so that a consistent and even ribbon edge can be secured by the stitching filaments without the need for expensive and complex assemblies to maintain the shape of the side loop 12 during its feed to the needle plate 40.
The present invention provides a needle plate 40 which has been improved such that a wire filament 14 can be guided to and incorporated with the side edge 12 of the ribbon material 10 during the stitching process. The needle plate 40 of the present invention is shown in FIGS. 4-6. The needle plate 40 includes a top portion 42 having conventional fabric engagement teeth 44, a feed carrier access slot 46, a fabric support tine 48 for supporting the fabric (ribbon material) adjacent to the moving needle, and a needle stitching slot 49. The needle plate 40 also includes a side portion 50 and a bottom portion 52. The side portion 50 includes a side groove 54 along the side of the support tine 48. The side groove 54 is of proper dimensions to effectively guide a sliding wire filament of a chosen size from a wire filament source (not shown) to the ribbon material 10, specifically along the ribbon's edge. A similarly shaped bottom groove 56 is disposed substantially inline with that of the side groove 54. As shown in FIG. 5, the wire filament 14 is guided by both side and bottom grooves (54, 56) without stress or deformation. The wire filament 14 is first guided from its source, and under the work plate 34 (FIG. 3), by the bottom groove 56 along the bottom portion of the needle plate 40 and then, by the side groove 54 along the side of the support tine 48 following a gradually inclined direction. The wire filament 14 eventually becomes located adjacent to the top portion of the needle plate 40 where it can easily be positioned within a fold of the ribbon's side edge 12 and secured to the ribbon material 10 during the stitching process.
Referring to FIGS. 2 and 3, one edge 11 of the ribbon material 10 is folded towards the center of the ribbon (downwardly in a preferred embodiment), forming a side edge 12 through which the wire filament 14 may positioned and secured. It is known in the stitching industry to loop the edges of a fabric. Any of the known techniques can be incorporated with the stitching machine 30 so that a side edge 12 of the ribbon material 10 is formed around the wire filament 14 just prior to the stitching process. It is preferred, however that the fold in the side edge 12 be limited according to the size of the wire used. It is preferable that with any wire used, the side edge 12 be such that when it is in tight engagement around the wire filament 14, the actual edge 11 of the ribbon material 10 will at most, just contact the surface of the adjacent ribbon material 10. If a larger fold is formed, the ribbon material 10 may buckle and fold when it overlaps the ribbon material 10 and an undesirable seam will result. Such buckling may also cause the secured ribbon edge to be uneven and could create spots along the wire filament 14 where the ribbon material is not in tight engagement with the wire.
In operation, a supply of an appropriate decorative trim filament 18 and a supply of binding filament 20 are loaded in a conventional manner into a standard stitching machine, like the preferred Merrow or Pegasus machine. A wire filament 14 is fed through the needle plate 40, guided by both the side groove 54 and the bottom groove 56 and is ultimately drawn with the ribbon by the rollers 32. The ribbon material 10 is positioned in a conventional manner onto the work plate 34 of the stitching machine 30. As the machine operates, the edge of the ribbon material 10 is formed into a fold around the adjacent wire filament 14. The previously described stitch is then produced around the edge loop 12 and the enclosed wire 14. The stitching process creates the necessary pull required to ensure tight engagement between the wire filament 14 and the ribbon material 10.
The tightness of the stitch can be regulated by adjusting the cams of the stitching machine. In a preferred embodiment, the cams are adjusted so that the trim filament is wrapped tightly, with each turn of the filament just touching or overlapping each adjacent turn, so that the wire and the edge of the ribbon are covered over. It will also be appreciated by skilled practitioners that more than one trim filament or binding filament can be used on each edge of the ribbon. Preferably, one or two trim filaments is used and one binding filament is used.
Although preferred embodiments of the invention are described in detail herein, it will be appreciated by skilled practitioners that the invention can also be practiced in other embodiments, and the present examples do not serve to narrow the appended claims. | This invention relates to decorative ribbons, and to methods and machines for making them. More specifically, the invention relates to fabric ribbons that are edged with wire and trimmed with an overlay of decorative thread.
According to the invention, a run of fabric ribbon is simultaneously edged with wire and tightly bound with a binding filament (such as monofilament) and a trim filament (such as decorative thread). This is done in a single operation. The result is a unique ribbon construction, which has many desirable properties. The new ribbons are flexible, but will retain their shape when bent, twisted or tied into a desired configuration. They are elegantly simple in design and provide a novel streamlined finished product with components that are firmly bound together. The ribbons provide an improved edge and trimming where the wire meets the fabric. They represent an improvement in strength and design, by conveniently providing a two-sided edged ribbon rather than a one-sided edged ribbon with seams and having a definite front side and back side. | 3 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a multiple cylinder engine such as a V-type 2-cylinder engine and, more particularly, to a multiple cylinder engine capable of controlling an air/fuel ratio accurately.
2. Description of Related Art
In a small general-purpose engine to be used in an agricultural machine, a small-sized power generator or the like, a carburetor is generally employed in an intake system of the engine. In case there is considered the response of the engine at its acceleration/deceleration, the countermeasures against exhaust emissions of recent years and the homogeneous distribution of mixtures, however, it is thought that a fuel injection device (especially, an electronic control type fuel injection system) for injecting fuel directly into the intake pipe is advantageous over the carburetor. From this background, the fuel injection device is being adopted at present.
Here will be briefly described the construction of the fuel injection device by exemplifying a fuel injection type V-type engine for adjusting a fuel injection quantity by measuring an intake pipe vacuum downstream of a throttle valve and by converting the measured vacuum into an intake air flow. This fuel injection device is constituted, as shown in FIG. 9 , to include a fuel injection valve 81 , a fuel pressure adjustor 82 and a pressure sensor 83 shared by individual cylinders 80 and 80 . An intake passage 84 , as shared by the individual cylinders 80 and 80 , and the fuel pressure adjustor 82 are connected by conduit 86 . The intake passage 84 and the pressure sensor 83 are connected by conduit 85 . The pressure sensor 83 has a vacuum inlet port 85 a , which is opened into the intake passage 84 downstream of a throttle valve 87 .
In the case of this constitution, the intake pressure is averaged conveniently for the fuel pressure adjustor 82 , even if it is introduced from the intake passage 84 shared by the two cylinders into the single fuel pressure adjustor 82 . As the peaks of the intake pressure of the intake pipe are excessive close on the time axis, however, they are unclear for the pressure sensor 83 to detect, so that the accuracy of the injection quantity control is deteriorated.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a multiple cylinder engine capable of controlling an air/fuel ratio accurately by accurately detecting the fluctuations of a vacuum in an inlet passage of the engine, due to a change in the openings of throttle valves.
According to the first aspect of the present invention, a multiple cylinder engine comprises: a plurality of cylinders; a plurality of intake passages for feeding intake air to the individual cylinders independently of each other; a fuel injector provided for each intake passage; a throttle valve provided for each intake passage; a pressure sensor for detecting the pressure of one of the intake passages; and fuel control means for controlling the injection quantity of the fuel injector of each cylinder by using the detected pressure.
According to aspects of the present invention, the pressure sensor detects the vacuum from one of the intake passages provided independently for each cylinder. With this the detection is not influenced by another cylinder so that it can detect the vacuum accurately. Therefore, the detection accuracy of the intake air flow based on the vacuum is improved, which increases the accuracy of the fuel control by the fuel control means on the basis of the vacuum. Here, an intake air flow of the intake passage, in which the vacuum is not detected, can be obtained from the vacuum in the intake passage, in which the vacuum is detected. The intake air flow of the intake passage, in which the vacuum is not detected, is obtained by predetermining its ratio to the intake air flow of the intake passage, in which the vacuum is detected, and by storing the determined data in the fuel control means.
Preferably, the multiple cylinder engine further comprises a vacuum inlet passage having an inlet port opened in the intake passage for introducing the pressure of the intake passage into the pressure sensor, and the vacuum inlet passage includes a throttle portion having a passage area of one ninth or less as large as that of the inlet port.
Thus, if a dynamic pressure is detected at the time of detecting the vacuum value, the peak values and the bottom values of the waveforms of the pressure fluctuations become unclear so that the fluctuations of the vacuum in the air intake passage due to the small change in the openings of the throttle valves are hard to detect. As a result, it is difficult to control the air/fuel ratio accurately. However, with the above structure, the vacuum inlet passage is provided with the throttle portion so that the waveforms of the pressure fluctuations, as might otherwise be made unstable by the influence of the dynamic pressure, are stabilized to clarify the peak values and the bottom values of the waveforms obtained thereby to improve the accuracy of the vacuum detection by the pressure sensor. As a result, it is possible to control the air/fuel ratio accurately. Moreover, the passage area of the throttle portion is set to one ninth or less of that of the inlet port so that the fluctuations of the vacuum due to the small change of the throttle valve opening can be tolerated to detect the vacuum accurately.
Preferably, a throttle body forming a section of the intake passage and having the throttle valve and an intake port of the cylinders is connected by an intake manifold, and the vacuum inlet passage is formed in the throttle body and a outlet portion of the vacuum inlet passage is formed in the mating face of the throttle body with the intake manifold.
Thus, the vacuum inlet passage leading to the pressure sensor and the section of the intake passage communicating with the vacuum inlet passage are formed in the throttle body so that a separate member for forming the vacuum inlet passage and mounting parts such as bolts can be eliminated to reduce the number of parts and to facilitate the assembly. Moreover, a outlet portion of the vacuum inlet passage is positioned in a mating face in the throttle body with the intake manifold so that this portion can be easily formed.
Preferably, the multiple cylinder engine further comprises a fuel pressure adjustor for adjusting the pressure of the fuel to be fed to the fuel injectors. A pressure introduction passage is formed in the throttle body or in the intake manifold for introducing the pressure of the each intake passage into the fuel pressure adjustor. The pressure introduction passage has its leading end portion positioned in the mating face between the throttle body and the intake manifold.
Thus, the pressure introduction passage is formed in the throttle body or in the intake manifold, and its leading end portion is positioned in the mating face between the throttle body and the intake manifold so that separate members for forming those passages and mounting parts such as bolts can be eliminated to reduce the number of parts and to facilitate the assembly. Moreover, the pressure introduction passage has its leading end portion positioned in the mating face between the throttle body and the intake manifold so that it can be easily formed.
Preferably, the leading end portion includes an expansion chamber and an introduction port for connecting the expansion chamber to the each intake passage. The introduction port has a passage area set smaller than a maximum passage area of the expansion chamber.
Thus, air introduced from the intake passages into the introduction port is averaged gently in its pressure by the expansion chamber. When the air is introduced from the expansion chamber into the fuel pressure adjustor, therefore, the fuel pressure can be adjusted to the optimum by the fuel pressure adjustor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional front elevation showing a V-type 2-cylinder engine according to an embodiment of the present invention;
FIG. 2 is a front elevation showing an essential portion of the V-type 2-cylinder engine according to the same embodiment, and shows an arrangement of a throttle body, a fuel pressure adjustor, a fuel introduction pipe and so on;
FIG. 3 is a longitudinal section of an essential portion of the V-type 2-cylinder engine according to the same embodiment, and shows an intake passage, a fuel passage and so on;
FIG. 4 is a sectional view of line IV—IV of FIG. 1 ;
FIG. 5 is a top plan view showing an essential portion of the V-type 2-cylinder engine according to the embodiment of the present invention;
FIG. 6 is a sectional view taken along line VI—VI of FIG. 2 , to which an intake manifold is added;
FIG. 7 is a sectional view taken along line VII—VII of FIG. 2 , to which the intake manifold is added;
FIGS. 8 (A) and 8 (B) are diagrams illustrating relationships between a vacuum value on pressure fluctuations and the time with and without a throttle portion in a vacuum outlet passage; and
FIG. 9 is a sectional view showing a fuel injection device of the conventional industrial engine.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A V-type 2-cylinder engine according to an embodiment of the present invention will be described with reference to FIG. 1 to FIG. 5 . In FIG. 1 , the V-type 2-cylinder engine 1 is a general-purpose engine to be used in an industrial machine, an agricultural machine or the like. The V-type 2-cylinder engine 1 includes: cylinders 2 and 3 arranged in the V-shape at different angle (e.g., 90 degrees) positions around a crank axis CT; a throttle body 4 (although only its front end flange portion is shown) arranged in the V-shaped space (or the bank space) between those cylinders 2 and 3 ; and an intake manifold 5 interposed between the throttle body 4 and the intake ports 2 a and 3 a of the two cylinders 2 and 3 . The throttle body 4 is connected, as shown in FIG. 3 , to an upper air cleaner D through an intake duct member 15 which is mounted on a front end flange face 4 e . On the bottom portion of the air cleaner D, there is mounted an intake temperature sensor A for detecting the temperature of the cleaned air in the air cleaner D.
The individual cylinders 2 and 3 shown in FIG. 1 are provided with cylinder bodies 2 b and 3 b , in which pistons P are slidably fitted, and cylinder heads 2 c and 3 c . These cylinder heads 2 c and 3 c are provided with ignition plugs 2 d and 3 d and intake valves 2 e and 3 e . The reciprocal motions of the pistons P are transmitted as rotational motions through a connecting rod R to a crankshaft K.
Between the individual cylinders 2 and 3 , moreover, there are mounted fuel injectors 6 and 7 , which are inclined and have their leading end nozzles 10 a and 10 b oriented obliquely downward to the outer side. These fuel injectors 6 and 7 are individually mounted in mounting holes 8 a and 8 b , which are formed at symmetrical positions in the intake manifold 5 , through ring-shaped rubber seals 9 a and 9 b with the leading end nozzles 10 a and 10 b being directed toward the intake ports 2 a and 3 a of the individual cylinders 2 and 3 .
In the V-type 2-cylinder engine 1 , moreover, there are formed two intake passages 11 a and 11 b for feeding the intake air independently to the individual cylinders 2 and 3 . The throttle body 4 is provided with two intake passages 4 a and 4 b forming sections of the intake passages 11 a and 11 b . As shown in FIG. 3 , the intake passages 4 a and 4 b are individually provided therein with throttle valves 4 c . In the intake duct member 15 , too, there are formed two intake passages 15 a and 15 b which communicate with the intake passages 4 a and 4 b to form sections of the intake passages 11 a and 11 b.
On the upper side of the throttle body 4 , there is disposed an injection fuel introduction portion 12 a of a fuel passage 12 . Two fuel introduction pipes 13 for feeding the fuel from the injection fuel introduction portion 12 a to the fuel injectors 6 and 7 ( FIG. 1 ) are fitted and supported between the throttle body 4 and the intake manifold 5 respectively. The fuel introduction pipes 13 are supported in such a manner that protrusions 13 a formed at one-side end of the fuel introduction pipe 13 is inserted into a positioning hole 5 a formed in the intake manifold 5 , and a leading end portion of the fuel introduction pipe 13 is inserted into a fuel introduction pipe mounting hole 12 b formed in the fuel introduction portion 12 a through O-rings 12 c , as shown in FIG. 4 . As a result, the fuel introduction pipes 13 are supported between the throttle body 4 and the intake manifold 5 . Moreover, the throttle body 4 and the intake manifold 5 are fixed by bolts 21 b which are fastened in threaded holes 17 of the intake manifold 5 shown in FIG. 3 .
In the upper portion of the throttle body 4 , moreover, there is formed a vacuum inlet passage 18 of FIG. 6 for extracting the intake pressure of the intake passage 11 a downstream of the throttle valve 4 c , and the leading end of the vacuum inlet passage 18 is connected to a pressure sensor C ( FIG. 7 ) so that the intake pressure in one intake passage 11 a (or the other intake passage 11 b ) can be detected by the pressure sensor C. This pressure sensor C is mounted on the back portion of the intake manifold 5 through a bracket 19 , as shown in FIG. 5 . The pressure value detected by the pressure sensor C is sent as a detection signal to a computer 20 of FIG. 1 or fuel control means. With a map programmed in advance in the computer 20 , the fuel injection rates of the fuel injectors 6 and 7 of the individual cylinders 2 and 3 are determined from the relationship between the pressure value and the engine speed rpm. In this determination of the fuel injection rates, the detection data of the intake temperature sensor A and a water thermometer B inserted in a cooling water passage 22 shown in FIG. 3 are also inputted to the computer 20 so that the injection rates of the fuel are corrected.
On the other hand, the fuel injectors 6 and 7 shown in FIG. 1 are inserted between the fuel introduction pipes 13 and the intake manifold 5 and supported in a sealed state such that their leading end nozzles 10 a and 10 b are supported through the rubber seals 9 a and 9 b in the mounting holes 8 a and 8 b of the intake manifold 5 and such that their root end sides are inserted into the fuel injector inserting holes 13 a of the fuel introduction pipes 13 through shock absorbing dampers 6 a and O-rings 6 b , as described by representing the case of the fuel injector 6 in FIG. 4 . Here, the injection fuel introduction portion 12 a is desirably formed integrally with the throttle body 4 , but may also be constructed by making it as a separate member and by mounting it on the throttle body 4 by mounting means such as fasteners.
Between and slightly over the fuel injectors 6 and 7 , as shown in FIG. 2 , there is mounted a common fuel pressure adjustor 14 for adjusting the pressure of the fuel to be fed to the fuel injectors 6 and 7 . This fuel pressure adjustor 14 is connected in a sealed state, as shown in FIG. 3 , by mounting a bypass pipe portion 14 a extended from its front portion (as located on the right side of FIG. 3 ) through an O-ring 14 b in a fuel pressure adjustor mounting hole 4 d formed in the throttle body 4 , and is mounted on the throttle body 4 by means of not-shown bolts.
Moreover, the fuel pressure adjustor 14 is arranged, as shown in a top plan view in FIG. 5 , on one side (or the front side) across the fuel injectors 6 and 7 in the longitudinal direction along the rotation axis CT of the engine. On the other side (or the rear side), there is arranged the pressure sensor C for detecting the pressure in the intake passages 11 a and 11 b . As shown in FIG. 5 , the fuel in the fuel tank (although not shown) is introduced through the injection fuel introduction portion 12 a into the fuel introduction pipes 13 of FIG. 3 by attaching the fuel pipe from the fuel tank to a fuel connection pipe 16 which is connected to the injection fuel introduction portion 12 a in the throttle body 4 . As shown in FIG. 3 , the fuel introduced into the injection fuel introduction portion 12 a flows, as indicated by a solid arrow a, from the fuel introduction pipes 13 into the fuel injectors 6 and 7 (FIG. 2 ), whereas the excess fuel is returned, as indicated by a dotted arrow b, from the fuel pressure adjustor 14 via a return passage 28 to the fuel tank. With this arrangement, the fuel injection type V-type 2-cylinder engine can be easily reconstructed by replacing the carburetor of the general carburetor type V-type 2-cylinder engine and the manifold for the carburetor, by the throttle body 4 and the intake manifold 5 . In accordance with the needs, therefore, the specifications can be quickly changed from the carburetor type to the fuel injection device type of the invention.
At an intake stroke of the V-type 2-cylinder engine thus constructed, as the intake valves 2 e and 3 e shown in FIG. 1 are opened and the pistons P go down, the pressures in the cylinders 2 and 3 drop so that the air is sucked from the intake passages 11 a and 11 b formed in the throttle body 4 and the intake manifold 5 . At this time, the intake vacuum of the sucked air is detected in a high accuracy by the pressure sensor C (FIG. 5 ), and the detected value obtained is inputted together with the engine speed to the computer 20 or the fuel control means so that the fuel injection rate is determined. At this time, the detected data of the intake temperature sensor A and the water thermometer B ( FIG. 3 ) are also inputted to the computer 20 to correct the injection rates determined. On the basis of the instructions of the computer 20 , moreover, the injection rates by the fuel injectors 6 and 7 are controlled, and the fuels in the controlled injection rates are injected from the fuel injectors 6 and 7 into the intake passages 11 a and 11 b of the intake manifold 5 so that the optimum mixtures are homogeneously distributed and fed to the cylinders 2 and 3 .
Here, the fuel injectors 6 and 7 are individually provided for each cylinder 2 and 3 in the V-space of the engine so that the mixtures can be homogeneously distributed. Moreover, not only the fuel injectors 6 and 7 but also the accompanying fuel pressure adjustor 14 is arranged in the V-space, and the intake passages 11 a and 11 b and the fuel passage 12 are integrally formed in the throttle body 4 and the intake manifold 5 , so that the pipes to be employed can be reduced to the necessary minimum to make a compact structure as a whole. Moreover, the fuel injectors 6 and 7 and the fuel introduction pipes 13 are mounted on the throttle body 4 and the intake manifold 5 by not fastening but inserting them, so that their mountability and assembling performance are improved.
FIG. 6 and FIG. 7 describe the detail of the vacuum extracting portions of the intake passages. In order to make the details of the vacuum inlet passage 18 especially understandable, however, the fuel injectors 6 and 7 and the fuel pressure adjustor 14 are omitted in FIG. 6 and FIG. 7 for convenience.
In FIG. 6 , the vacuum inlet passage 18 is formed by extending it normal to a flange face 4 f of a mating face with the intake manifold 5 in the throttle body 4 . The vacuum inlet passage 18 is provided at its one end with an inlet port 18 a opened into one intake passage 4 a (or 11 a ) and at its other end with a thin groove 18 c of FIG. 2 (outlet portion of the vacuum inlet passage) opened in the flange face 4 f . One end portion of the groove 18 c is connected, as shown in FIG. 7 , to the pressure sensor C through a communication passage 23 formed in the intake manifold 5 and through a connection pipe 24 . In the vacuum inlet passage 18 , as shown in FIG. 6 , there is formed a throttle portion 18 b which has a passage area set to about one ninth or less as large as the passage area of the inlet port 18 a . If the passage area of the throttle portion 18 b exceeds about one ninth of that of the inlet port 18 a , the vacuum value to be detected by the pressure sensor C ( FIG. 7 ) may be made unstable by the influences of a dynamic pressure.
As a passage for detecting a controlling vacuum to control the fuel pressure adjustor 14 of FIG. 7 , on the other hand, there is formed in the throttle body 4 a pressure introduction passage 25 for introducing the pressure in the intake passages 11 a and 11 b into the fuel pressure adjustor 14 . This pressure introduction passage 25 is positioned at its portion or leading end portion at a mating face 5 f with the throttle body 4 in the intake manifold 5 . The leading end portion is opened in the flange face 4 f of the throttle body 4 . This leading end portion is provided, as shown in FIG. 2 , with an expansion chamber 25 a , and introduction ports 25 b and 25 c for connecting the expansion chamber 25 a and the intake passages 4 a and 4 b . The passage area of the introduction ports 25 b and 25 c is set smaller than the maximum passage area of the expansion chamber 25 a . Here, the passage area of the expansion chamber 25 a is a sectional area normal to the air flow in the expansion chamber 25 a . Moreover, the introduction ports 25 b and 25 c are formed to have small sections, and the expansion chamber 25 a is desired to have a passage area of at least five times that of the introduction ports 25 b and 25 c.
Both the vacuum inlet passage 18 of FIG. 6 and the expansion chamber 25 a of FIG. 7 are formed in the direction normal to the flange faces 4 f and 5 f of the mating face between the throttle body 4 and the intake manifold 5 , so that they can be easily machined.
A detection path of the control vacuum for controlling the fuel pressure adjustor 14 is formed in the throttle body 4 , but a pressure introduction passage 25 ′ may be formed in the intake manifold 5 , as indicated by phantom lines of FIG. 7 . Moreover, the detection path may be formed over the intake manifold 5 and the throttle body 4 by forming, for example, only the introduction ports 25 b and 25 c in the intake manifold 5 and by forming the remaining portion in the throttle body 4 .
According to the vacuum detecting means thus constructed, the pressure detected by the pressure sensor C of FIG. 7 is the vacuum from one intake passage 4 a (or 11 a ) but not the vacuums from a plurality of intake passages, and the vacuum is not averaged so that it can be accurately detected.
Therefore, the detection accuracy of the intake air flow based on the vacuum is improved to increase the accuracy of the fuel control by the computer 20 ( FIG. 1 ) on the basis of the vacuum. Here, the intake air flow of the intake passage 11 b , the vacuum of which is not detected, can be easily obtained from the vacuum, i.e., the intake air flow of the intake passage 11 a , the vacuum of which is detected, by predetermining the ratio of the intake air flow of the intake passage 11 a and the intake passage 11 b and by storing the ratio data in the computer 20 .
Concerning the pressure sensor C of FIG. 7 , moreover, the detected vacuum value is so stabilized in the waveform of the pressure fluctuations by the existence of the throttle portion 18 b disposed in the vacuum inlet passage 18 that the peak value and the bottom value become clear, as illustrated in FIG. 8 (A). Therefore, the fuel injection rate can be adjusted to establish a desired air/fuel ratio. Without the throttle portion, as illustrated in FIG. 8 (B), the pressure fluctuations are made unstable by the influences of the dynamic pressure so that the peak value and the bottom value become unclear, resulting in failure to establish the desired air/fuel ratio.
Here, the embodiment thus far described has been exemplified especially by the V-type 2-cylinder engine, but the present invention can be similarly applied to all other multiple cylinder engines.
Numerous modifications and alternative embodiments of the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode carrying out the invention. The detail of the structure and/or function may be varied substantially without departing from the spirit of the invention and all modification which come within the scope of the appended claims are reserved. | A multiple cylinder engine controls an air/fuel ratio accurately by improved detection of the fluctuations in a vacuum due to a change in the openings of throttle valves. The multiple cylinder engine includes a plurality of intake passages that independently feed intake air to cylinders; fuel injectors; throttle valves; a pressure sensor; and a fuel controller that controls fuel injection of each cylinder using the detected pressure. The multiple cylinder engine may further include a vacuum inlet passage having an inlet port opened into intake passages that introduces the pressure of the intake passages into the pressure sensor. The vacuum inlet passage preferably includes a throttle portion having a passage area of no more than one ninth that of the inlet port. | 5 |
CLAIM OF PRIORITY
The present invention is a continuation of application Ser. No. 09/542,010, filed Apr. 3, 2000, now U.S. Pat. No. 6,606,754, which claims priority to provisional application 60/128,433, filed on Mar. 30, 1999.
FIELD OF INVENTION
The present invention relates to a pad that provides hypo/hyperthermia properties to a person using the pad.
BACKGROUND OF THE INVENTION
In U.S. Pat. No. 5,336,708, Chen discloses a gelatinous elastomer composite article. These articles, as disclosed by Chen, “include: GMG, MGM, MG 1 G 2 M, M 1 M 2 G 1 G 2 , M 2 M 1 G 1 G 2 , G 1 MG 1 G 2 , MG 1 G 2 , G 1 G 2 M, G 2 G 1 M, GM 1 M 2 G, G 1 M 1 G 2 M 2 M 1 , M 1 GM 2 GM 3 GM 4 , [sic] ect, where G=gel and M=material. The subscript 1, 2, 3, and 4 are different and are represented by n which is a positive number. The material (M) suitable for forming composite articles with the gelatinous elastomer compositions can include foam, plastic fabric, metal, concrete, wood, wire screen, refractory material, glass, synthetic resin, synthetic fibers, and the like. Sandwiches of gel/material . . . are ideal for use as shock absorbers, acoustical isolators, vibration dampers, vibration isolators and wrappers. For example the vibration isolators can be [sic] use under research microscopes, office equipment, tables, and the like to remove background vibrations.” U.S. Pat. No. 5,336,708, col. 3, lines 35-51. Chen further discloses, “generally the molten gelatinous elastomer composition will adhere sufficiently to certain plastics (e.g., acrylic, ethylene copolymers, nylon, polybutylene, polycarbonate, polystyrene, polyester, polyethylene, polypropylene, styrene copolymers, and the like) provided the temperature of the molten gelatinous elastomer composition is [sic] sufficient high to fuse or nearly fuse with the plastic. In order to obtain sufficient adhesion to glass, ceramics, or certain metals, sufficient temperature is also required (e.g., above 250° F. [121° C.]).” U.S. Pat. No. 5,336,708, col. 9, lines 8-18 (brackets added for consistency of temperature comparison).
Elkins in U.S. Pat. No. 4,884,304 describes a bedding system with selective heating and cooling of a person. That system has, from top to bottom, in order: a top mattress cover, a gas envelope and a multiplicity of liquid flow channels. The multiplicity of liquid flow channels is accomplished by a conventional hypo/hyperthermia blanket. The details of this conventional blanket are set forth in this patent. A problem with this system occurs when a person is on the mattress cover. When the person is on that mattress cover, the person has two sides: (1) a “contacting side” that touches the mattress cover and (2) the “exposed side” that does not touch the mattress cover. The person disperses the gas-envelope and only certain portions of the contacting side contact the flow channels. As shown in FIG. 5 of that patent, the shoulders and other peripheral points of the contacting side of the person, such as arms, do not contact the flow channels. Thereby, that bedding system fails to transfer the desired temperature of the flow channels uniformly to all sections of the contacting side of the person.
M. Figman in U.S. Pat. No. 3,266,064, and von der Heyde in U.S. Pat. No. 5,887,304 illustrate conventional convective medium mattress system which essentially has a lower “box spring” and a mattress made of rubber, foam, or conventional mattress materials that an individual or object lies thereon. In each embodiment, the lower box spring has a cavity that the medium enters and distributes throughout. The medium then escapes from the cavity through apertures of the mattress.
A problem with these apertures 89 is that they kink 90 when an adult lies 22 thereon, as shown in FIG. 8 . Please note that von der Heyde's system is designed for an infant, not an adult. And an infant is of such low weight that kinking is essentially nonexistent.
When kinking occurs, the medium is prevented from contacting the body. And when the medium does not contact the body, the medium is unable to treat the hypothermia or hyperthermia portions of the patient that contact the mattress, or even cool or heat the portions of the patient that contact the mattress.
The present invention solves this problem.
SUMMARY OF THE INVENTION
The present invention relates to a first conformable material having a three-dimensional shape and a first hypothermia and/or hyperthermia device.
BRIEF DESCRIPTION OF THE FIGURES
A preferred embodiment of the present invention is described in detail hereinafter with reference to the accompanying drawing, in which:
FIG. 1 is a cross-sectional view of the present invention; and
FIGS. 2-7 are alternative embodiments of FIG. 1 .
FIG. 8 is prior art of an adult patient on a conventional mattress system with apertures.
FIG. 9 is the present invention of an adult patient on a gelatinous elastomeric material with apertures.
FIG. 10 is an alternative embodiment of the present invention with a conventional blanket.
FIG. 11 is an alternative embodiment of FIG. 10 with a convective blanket.
FIG. 12 is an alternative embodiment of FIG. 7 .
FIG. 13 is an alternative embodiment of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a pad 10 having a first sealable bag 12 , a first hypothermia and/or hyperthermia device 14 , and a pad cover 16 . The bag 12 contains at least a first conformable material 18 , and a thermally conductive medium 20 . The thermal conductive medium 20 is any liquid or viscous gel that transfers energy generated by the device 14 to a patient (not shown). Examples of this liquid include water, water-based solutions, oil-based solutions, oils, alcohols, mixtures thereof, and viscous gels.
The conformable material 18 is any material having apertures that do not easily kink, preferably, a gelatinous elastomeric material. Examples of types of gelatinous materials, which are heat formable and heat reversible, are fully described in U.S. Pat. Nos. 4,369,284, 4,618,213, 5,262,468, 5,336,708, and 5,508,334, which are hereby incorporated by reference herein, and those made by Pittsburgh Plastic. The gelatinous materials manufactured by Pittsburgh Plastic are allegedly distinct from the patented types. This conformable material can be of any shape or design, so long as it has a three-dimensional shape that supports a patient or object on the pad 10 .
The hypothermia and/or hyperthermia device 14 is any conventional hypo/hyperthermia blanket—an example of this blanket is the MUL-T-PAD® or the THERMACARE® blanket by Gaymar Industries, Inc. of Orchard Park, N.Y.—and its corresponding pump—the MEDI-THERM II® temperature regulator by Gaymar Industries, Inc. of Orchard Park, N.Y.—, an electric blanket, a cold compress, and a convective device. The convective device pumps or blows air or other gaseous medium (collectively “Air”) having a predetermined temperature. The Air obtains the desired temperature in a conventional Air temperature regulator (for example, an air conditioner, a heat pump, a ThermaCare® blower unit, or the MEDI-THERM II® temperature regulator) and then circulates through a mesh screen like the Air Queen by Teijin, Inc. or a non-woven polymeric device having a plurality, of tubes with numerous apertures therein. The Air is then distributed throughout the entire pad 10 . In any embodiment of device 14 , the device 14 affects the temperature that a patient (not shown) or object (not shown) is exposed to, and, in some embodiments, the medium 20 that encompasses the conformable material 18 .
The bag 12 is any sealable instrument that contains at least the thermally conductive medium 20 and conformable material 18 in place. Preferably, the bag 12 is plastic, and it can be sealed thermally, acoustically, by a zipper, zip locked, or even by Velcro®.
The pad cover 16 is any conventional material used to cover a pad 10 . The pad cover 16 can encompass the entire pad 10 , the preferred embodiment as shown, or cover the pad 10 like a conventional mattress sheet. In either embodiment the pad cover 16 can be cloth, leather, plastic or conventional cover material. The materials of the pad cover 16 allow the patient or object, on the pad 10 , to feel the desired temperature of the pad 10 (Air or medium 20 ). The pad cover 16 can also allow moisture to pass through it. Thereby, it helps control the patient's temperature and prevents overcooling or overheating.
Turning to FIG. 2 , a patient 22 disperses a portion of the thermal conductive medium 20 in the bag 12 and contacts at least a portion of the conformable material 18 when the patient 22 lies on the pad 10 . The conformable material 18 provides support to the patient 22 , increases the effective surface contact of the pad 10 to the patient 22 to ensure greater desired thermal conductivity to the patient 22 , maintains the stability of the bag 12 , and reduces the pressure to the patient 22 . By maintaining the stability of the bag 12 , the conformable material 18 ensures the patient (or object) 22 , on the pad 10 , from directly contacting the hypothermia and/or hyperthermia device 14 . In other words, the patient 22 does not “bottom out” to or directly contact the device 14 .
In a preferred embodiment, the conformable material 18 has apertures 24 . The apertures 24 , in this embodiment, go from the bottom to the top of the material 18 and ensure the thermal conductive medium 20 is between the patient 22 and the hypothermia and/or hyperthermia device 14 . However, in order to decrease, and essentially avoid, kinking—which is discussed above and, as a reminder, inhibits the medium 20 or the Air from contacting the patient—and which is common in many mattress materials, the preferred embodiment of the conformable material 18 is a gelantinous elastomer material. The gelantinous elastomer material has a structure design that admittedly bends and indents, as shown in FIG. 9 , when a patient lies thereon, but does not kink. Thereby, the Air or medium can go through the apertures 24 .
The hypothermia and/or hyperthermia device 14 heats or cools the thermal conductive material 20 and the patient 22 to a predetermined temperature. Since the thermal conductive material 20 contacts most, if not all, portions of the contacting side 23 of the patient 22 , the material 20 ensures a uniform, or nearly uniform application of the predetermined temperature to the contacting side 23 .
Turning to FIG. 3 , the pad 10 contains at least a second bag 12 a . The second bag 12 a has at least a second conformable material 18 a and a second thermal conductive material 20 a . The second thermal conductive material 20 a , the second bag 12 a , and the second conformable material 18 a can be the same or different materials as the previously listed corresponding elements 12 , 18 , 20 .
Turning to FIG. 4 , an alternative embodiment of FIG. 3 is shown. A second hypothermia and/or hyperthermia device 14 a is positioned under the second bag 12 a . The second hypothermia and/or hyperthermia device 14 a can be set at the same or different temperature as the hypothermia and/or hyperthermia device 14 . Thereby, the first thermally conductive material 20 can apply one temperature to one portion of the contacting side 23 b of the patient 22 and the second thermally conductive material 20 a can apply the same or a different predetermined temperature to another portion contacting side 23 c.
Turning to FIG. 5 , an alternative embodiment of FIG. 4 is shown. A third conformable material 18 b underlies the hypothermia and/or hyperthermia devices 14 , 14 a . This material 18 b offers further support to the patient 22 , maintains the stability of the bags 12 , 12 a , and further reduces the pressure to the patient 22 . Obviously, this third material 18 b can underlie, or alternatively be over (not shown), the hypothermia and/or hyperthermia device(s) 14 , 14 a of FIGS. 1-4 .
Turning to FIG. 6 , an alternative embodiment of FIG. 1 is shown. The hyperthermia and/or hypothermia device 14 is within the bag 12 under, or alternatively be over (not shown), the conformable material 18 and surrounded by the thermal conductive medium 20 . In this embodiment, the conventional inlet-outlet 77 of the device 14 , i.e., the pump hoses of the MEDI-THERM II® system, protrudes from the sealed bag 12 . Obviously this embodiment can be used in the other embodiments illustrated in FIGS. 3 and 4 .
FIG. 7 illustrates an alternative embodiment of FIG. 1 , wherein the conformable material is not inserted in a bag 12 or surrounded by a medium 20 . In this embodiment, the hypothermia and/or hyperthermia device 14 is a convective unit and the Air goes through the apertures 24 of the gelatinous elastomer material 18 .
FIG. 12 illustrates an alternative embodiment of FIG. 7 . Along with the apertures 24 , the conformable material 18 has a plurality of side apertures 24 a interspaced between the upper wall and a lower wall of the material 18 . Side apertures 24 a receive Air and then distribute the Air throughout the conformable material 18 .
In one embodiment (like that shown in FIG. 7 ) the device 14 is positioned below the conformable material 18 . In yet another embodiment, as shown in FIG. 12 , the device 14 is positioned at an end 563 of the conformable material 14 . Thereby the Air goes into the side apertures 24 a and is distributed throughout the conformable material 18 and apertures 24 , to effect the patient's 22 temperature.
Turning to FIG. 13 , another embodiment of the present invention relates to the positioning of the hypothermia and/or hyperthermia device 14 . The device 14 can also be positioned above the conformable material 18 . The device 14 adjusts the temperature of the air within the pad 10 , and that air cools or heats or maintains the temperature of the patient 22 . The air also circulates through the pad 10 within the apertures 24 (and maybe 24 a ).
Turning to FIGS. 10 and 11 , the Air of FIG. 7 circulates under the cover 16 , and escapes from, preferably predetermined, a gap 345 in the cover. Extending from gap 345 is a tube 347 , flexible or not, that directs the Air under a conventional blanket 348 , as shown in FIG. 10 , or into an aperture 349 of a convective blanket 350 , like the THERMACARE® blanket by Gaymar Industries, Inc., as shown in FIG. 11 .
Alternatively, the pad cover 16 has a material that transfers the temperature to the patient but influences the Air to a predetermined gap(s) 345 in the pad 10 . The predetermined gap(s) 345 can be located anywhere within the pad, i.e. at the bottom of the pad, a side of the pad as shown in FIGS. 10 and 11 , if necessary, under the patient 22 , or under the blanket 348 directly.
Turning to the method of the invention the preferred embodiment of the present invention is as an operating table pad and/or any other structure or object used in an operating room or hospital-like mattress system, such as bed systems or seat cushions. An operating technician inserts at least one pad 10 , having a hypothermia and/or hyperthermia device 14 , and a conformable material 18 , under a predetermined area of a patient 22 . The technician then adjusts the device 14 to a predetermined temperature, in some instances the device 14 can only obtain one temperature. In either case, the device 14 adjusts the pad 10 to the predetermined temperature. At any time before or after the device 14 is initially adjusted to the predetermined temperature, the patient 22 lies on the pad 10 and the contacting side 23 of the patient 22 will be or is exposed to the predetermined temperature.
Although a particular preferred embodiment of the invention has been illustrated and described in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the invention defined by the claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: | The present invention relates to a first conformable material having a three-dimensional shape and a first hypothermia and/or hyperthermia device. This invention is used as a pad for sleeping, lying down, or sitting, to maintain a desired temperature to the contacting surface of a body to the pad. | 0 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to signals such as radar signals that are used for range and direction finding and for imaging surfaces and objects and, more particularly, to a class of such signals whose length and bandwidth are parametrized independently. These signals may be used by range and direction finding devices, such as radars and their acoustic equivalents, that have single or multiple transmitters and receivers.
Pulsed signals such as radio-frequency (RF) signals and acoustic signals commonly are used for determining the distance and direction to a target. Reflections of the signals from the target are received, and the distance to the target is inferred as the product of the round-trip travel time and the speed of the signals in the medium in which the signals propagate to and from the target. The direction of arrival (DOA) is identified e.g. from differential arrival times at the receivers of a receiver array. Co-pending U.S. patent application Ser. No. 10/571,693, that is incorporated by reference for all purposes as if fully set forth herein, teaches a method of transmitting acoustic signals from the top of a silo and receiving echoes of the signals from the contents of the silo at the top of the silo to measure the shape of the top of the contents of the silo and so infer the volume of the contents of the silo. FIG. 1 shows one such silo 100 , in cross-section. This application of pulsed signal range and direction finding is complicated by challenges including:
(i) The upper surface 104 a or 104 b of the silo contents 102 can be at a variable distance from the acoustic transmitters and receivers 106 . This distance varies in a wide range: from tens of centimeters ( 104 a ) to tens of meters ( 104 b ). This creates the following sub-challenges:
i-1: a need for signal-to-noise-ratio (SNR) enhancement of weak arrived reflected pulses.
i-2: a need for pulses of different lengths
The need for SNR enhancement follows, in addition to the mentioned wide dynamic range of the acoustic paths, from the following issues:
(A) Specific silo contents surface geometry and/or specific geometry of silo walls and/or due to kinds of granularity of the silo contents. In particular, if due to specific environmental factors named above the geometrically reflected acoustic ray trajectories miss the receivers and only weak diffuse scattered rays approach the receivers, then the requirement of SNR amplification becomes even more urgent. (B) The noises inside the silo.
(ii) In many cases, it is desirable that the transmission of the signal terminate before the process of acquisition of the signal starts at the receiver. Otherwise, the strong transmitted signal leaks into the acoustic receiver as a strong noise added to the possible weak received reflected signal of interest whose parameters are to be measured. This complicates the processing significantly. If transceivers serve both as transmitters and receivers for beamforming, as in U.S. Ser. No. 10/571,693, it also reduces the number of transceivers usable as receivers, since several transceivers will be still used for transmission; it also makes impossible the use of all transceivers for the simultaneous transmission to create a spatially sharp beam. Thus, for these and other technological reasons the separation of the transmission and the reception in time is essential. This results in the demand that the length of the transmitted pulse [equal to the time period of its transmission multiplied by the speed of sound] be slightly shorter than the distance to the upper surface of the silo contents. This constraint is essential to the silo measurements, while it is absent e.g. from “standard” applications such as RF radar where targets such as airplanes, are far away from the rangefinder.
(iii) Typically, as shown in FIG. 2 , the transmitted acoustic signal 110 in silo 100 returns back to receivers 106 not as a single pulse but as a sum [or “train”] of multiple reflections 112 , 114 . This multi-path phenomena is also known in musical acoustics as reverberation. It presents challenges to discrimination of different reflections [in particular, for point mapping upon the upper surface of the silo contents]. In particular, it would be desirable to have a short-in-time signal, without long tails or ripples, since the tail or ripple of one reflected signal may mix with another reflected signal and cover or “camouflage” the other reflected signal, thus making discrimination of the two reflected signals problematic or impossible. Thus: good separation of the received pulses in-time [after their pre-processing] is required, for time of arrival (TOA) determination and DOA determination and the output pulses [again, after pre-processing] need to be to be as short as possible in time to achieve good resolution and to have tails with very small peak-to-ripple ratios. This challenge is addressed below by an innovative design of the transmitted pulse, and innovative pulse processing.
The term “pre-processing” means the intermediate processing step. In typical prior art general radar or communication systems this includes application of e.g. Matched Filtering (MF) [correlation of the signal pulse with itself, which is an example of pulse compression] or application of other type of filtering which reduces the side-lobes, e.g. mis-matched filtering.
(iv) In addition, the transmitted acoustic pulse has to be band-limited. This follows from several reasons. The first reason is related to the transfer functions of the acoustic antenna (for example, a horn antenna) and of the [electro-mechanical] driver of the acoustic transducer, since the transmission in the frequency domain of high attenuation of the total transfer function is a waste of energy and causes warping of the signal shape. The second reason involves the acoustic noise in silos. Typically the noise is expected to be high at the low frequencies [usually less than 1 kHz] and thus the signal spectrum needs to be separated from these areas.
Note, that the Doppler effect of the signal frequency shift is not an issue for an acoustic rangefinder in a typical silo due to the slow movement of the material surface and the kilo-Hertz range of the carrier frequency. For example, for 1 cm/sec movement and a 5 kHz carrier, and assuming a speed of sound of 340 m/sec, the frequency shift is about 0.01/340*5000=0.14 Hz, which is negligible.
The following notation is used below:
(A) The Z-Transform and Sparsity
The standard notation for the z-transform of a sequence is used herein. For example, the z-transform of the Barker 5 sequence, [1 1 1 −1 1], is
b 5 ( z )=1 +z −1 +z −2 −z −3 +z −4
The notation b 5 (z 30 ) means:
b 5 ( z 30 )=1 +z −30 +z −60 −z −90 +z −120
This is the z-transform of a sparse sequence of length 121 with only five non-zero values equidistant from one another. The value 30 is the “sparsity” of the new sequence that has been created from the original sequence [1 1 1 −1 1]. The original Barker 5 sequence has a sparsity of 1. Such original sequences of unit sparsity also are referred to herein as “templates” from which sparse sequences are derived. In this example, b 5 (z) is the template of b 5 (z 30 ).
(B) Convolution
Several notations are used herein for convolution. All these notations are standard in the signal processing literature.
“ ” means convolution. For example, if s1=[1, 2] and s2=[1, 2, 3] then c=s1 [1, 4, 7, 6]. An alternative notation is are c=conv(s1, s2). In the z-transform domain, the z-transform of c is the product of the z-transforms of s1 and s2.
(C) Matched Filter
MF( . . . ) means a matched filtering operation on a sequence. For example, for a sequence [a b c d e], MF([a b c d e])=[e* d* c* b* a*]; where “*” means conjugation for complex-valued components. For real-valued sequences, MF( . . . ) is equivalent to time-reversal (or index-reversal) of the sequence.
The following references provide background for the prior art of ranging pulse construction and processing:
[BARKER 1953] Barker, R. H: “Group synchronizing of binary digital system” in Jackson, W, (Ed): Communication theory (Butterworths, London, 1953), pp. 273-287. [BORWEIN 2008] Borwein P., and Mossinghoff M. J., Barker sequences and flat polynomials (with P. Borwein), Number Theory and Polynomials (Bristol, U.K., 2006), J. McKee and C. Smyth, eds., London Math. Soc. Lecture Note Ser. 352, Cambridge Univ. Press, 2008. [CHEN 2002] Chen, R., and Cantrell B: “Highly bandlimited radar signals”, Proceedings of the 2002 IEEE Radar Conference , Long Beach, Calif., Apr. 22-25, 2002, pp. 220-226. [LEVANON 2004] Levanon N., and Mozeson E: Radar Signals, Wiley & Sons, New York, 2004, xiv+411 pp. [LEVANON 2005] Levanon N: “Cross-correlation of long binary signals with longer mismatched filters”, IEE Proc.—Radar, Sonar and Navigation, 152 (6), 372-382, 2005. [NATHANSON 1999] Nathanson F. E., Reilly J. P., cohere M. N.: “Radar Design Principles Signal Processing and the Environment”, 2 nd edition, SciTech Publishing, 1999, 720 pp.
Conventional Construction of a Phase-Coded Ranging Pulse
In the baseband (“BB”) representation, a phase coded ranging pulse is represented as a weighted sum of time-continuous baseband shapes [or functions] Ψ(t/t b ) which are equally distanced from each other by “bit” time t b [LEVANON 2004, Section 6]:
u BB ( t ) = ∑ m = 1 M s m · Ψ BB ( t t b - ( m - 1 ) ) ( eq . 1 A )
This signal is a continuous function of time t. The digital realization of the signal is sampled with a periodicity of T s ≦t b . The “signal bit length” L b is the number of samples per bit time, L b =t b /T s , rounded to the nearest integer.
The weight [or spreading] sequence, s={s m }, m=1:M, is typically a sequence with good correlation properties. In general, the shape function and the digital sequence may be real or complex valued. The sequence s does not have to be binary; the term “bit” time is thus used for historical reasons, since the first (and still widely used) spreading sequences are the Barker binary codes.
The baseband pulse u BB (t) needs to be up-converted at the transmitter to the carrier frequency f c by using standard techniques. It then needs to be down-converted at the receiver.
For the specific but very common case of a real-valued spreading sequence s and for real-valued shapes, one may write the transmitted pulse u(t), modulated by a carrier frequency f c in a way similar to (eq. 1A):
u ( t ) = ∑ m = 1 M s m · Ψ ( t t b - ( m - 1 ) ) ( eq . 1 B )
where the “passband shape” Ψ is Ψ BB multiplied by a sinusoid of frequency f c :
Ψ ( t t b ) = Ψ BB ( t t b ) · sin ( 2 π f c t + ϕ 0 ) ( eq . 1 C )
and φ 0 is an arbitrary phase. The phase can be chosen, for example, in such a way that Ψ(t/t 0 )=0 at the earliest time t for which Ψ(t/t 0 ) is defined [for example if Ψ(t/t 0 ) starts at t=0, one may choose φ 0 =0].
As described above, the digitally sampled baseband pulse u BB (t) is up-converted to the carrier frequency f c . Alternatively, the passband pulse u(t) is sampled digitally and converted directly to the transmitted analog signal by direct digital-to-analog conversion.
The “kernel” (defined below) illustrated in FIG. 5 below is an example of a sampled passband shape created by multiplying a Kaiser window baseband shape by a sinusoid.
Shape Functions and Bandwidth Considerations for Ranging Pulses
The simplest example of a shape function is the rectangular function, which has support, i.e., is non-zero, only in the interval t=[0,t b ] [LEVANON 2004, Section 6, p. 100]:
Ψ
BB
(
t
t
b
)
=
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(
t
t
b
)
=
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1
for
0
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t
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t
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0
for
t
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0
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t
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t
b
(
eq
.
2
A
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u
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=
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M
s
m
·
rect
(
t
t
b
-
(
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The rectangle shape attenuates frequency very poorly. The power spectrum of the pulse behave as a sine function [see NATHANSON 1999, pp. 544, 555]:
G ( f ) = sin 2 ( π ft b ) ( π ft b ) 2
Therefore, smoother functions need to be introduced to satisfy the bandwidth constraints.
One solution that applies to this problem is described in [LEVANON 2004, section 6.8, pp. 145-155], which cites the original article [CHEN 2002] and presents the shape as a Gaussian-windowed sine function: [LEVANON 2004, p. 151, equation 6.25]:
Ψ BB ( t t b ) = { sin ( π t t b ) · exp { - 1 2 σ 2 ( t t b ) 2 } π ( t t b ) for - 2 t b ≤ t ≤ 2 t b 0 for t < - 2 t b or t > 2 t b ( eq . 2 B )
In the above references, the parameter σ is suggested to be chosen as σ=0.7. The parameter t b is chosen to satisfy the bandwidth constraints [the spectrum vs. non-dimensional coordinate f−t b is shown in FIG. 6.42 on p. 153 and 6.45 on p. 154. of [LEVANON 2004]].
The above shapes all have time-support, i.e. they are non-zero, upon a [small, typically 1 or 2 or 4] integral number of t b intervals. This means that for the sampled signals, the signal bit length is equal to the length of the sampled shape function sequence for the rectangular shape function of equation (2A) and to one-quarter of the length of the sampled gaussian-windowed sine shape function of equation 2B.
Some Known Sequences with Good Correlation Properties
A typical ranging pulse is based upon a sequence with good correlation properties [see LEVANON 2004, Chapter 6, Sections 6.1, 6.2, 6.3, 6.4, 6.5, 6.7]. For example, the most celebrated ones are the Barker sequences introduced in 1953 by Barker [BARKER 1953]:
b3=[1,1,−1]
b4A=[1,1,−1,1]
b4B=[1,1,1,−1]
b5=[1,1,1,−1,1]
b7=[1,1,1,−1,−1,1,−1]
b11=[1,1,1,−1,−1,−1,1,−1,−1,1,−1]
b13=[1,1,1,1,1,−1,−1,1,1,−1,1,−1,1]
Each of these sequences has a relatively flat spectrum and also the exceptional property that the peak-to-maximal-ripple-ratio of its auto-correlation is equal to the length of the sequence. This ratio, when calculated in dB, is known in the radar literature as PSL [Peak Sidelobe Level]. For example for b5, this ratio is 5 to 1 [or PSL=10 log 10 (⅕ 2 )≈−14 dB]. The PSLs of the Barker codes are shown in [NATHANSON 1999, Table 12.1, p. 538].
All known Barker codes are listed above. To enlarge the pulse energy the longer pulses, that have more sequence elements, are used. Still, it is assumed that the autocorrelation properties of such sequences are good. One may find discussion of such codes and some examples e.g. in [LEVANON 2004, Chapter 6, Table 6.3 pp. 108-109], where the sidelobe level is shown, while the peak level corresponds to the length of the sequence; see also [NATHANSON 1999, pp. 537-541, especially the Table 12.2 on pp. 540], where also the number of different possible sequences having the same sidelobe level is presented].
Modern mathematical review of generalizations of Barker sequences may be found in [BORWEIN 2008]. In the mathematical literature, the Littlewood polynomials [polynomials with coefficients ±˜1] are discussed. As an example, the following two sequences, representing the Littlewood polynomials with good autocorrelation properties, are listed in [BORWEIN 2008] and are given as:
seq20=[1,1,1,1,1,−1,1,−1,−1,−1,1,−1,1,1,−1,−1,−1,1,1,−1]
seq25=[1,1,1, −1, −1, −1,1,1,1,1,1,1,1, −1,1, −1,1, −1, −1,1, −1,1,1, −1]
Nested Sequences
A well-known way to construct longer sequences is to use nested codes [see LEVANON 2004, section 6.1.2, pp. 107-109, and LEVANON 2005]. This method is also known as code concatenation (or combination); if two Barker codes are used, the code is also named Barker-squared, see [NATHANSON 1999, pp. 541-542]. For example, instead of 1's and −1's in the binary code, such as a Barker code or a Littlewood polynomial, one may insert another code. To illustrate this approach let us use Barker b5 as a template, and an arbitrary Barker sequence “b” of length “L”; then one may write a sequence of length L·5:
nested_sequence — Lx 5 =[b,b,b,−b,b]
Typically, a Barker code is nested inside of another Barker code. As an example, one may use Barker 5 as the “b” sequence, b=b5, and obtain the 5×5 nested Barker code of length 25:
nested_sequence — 5×5=[ b 5 ,b 5 ,b 5 ,−b 5 ,b 5]
The nested code obtained by nesting Barker b13 into itself, 13×13 is mentioned in the literature; see for example [LEVANON 2005]. An example of a very long code using four combined Barker codes: 5×13×13×13 (with total length 10,985) is mentioned in [NATHANSON 1999, p. 542].
Note that nesting does not improve the peak-to-maximum-ripple ratios in the autocorrelation of the nested code [LEVANON 2004]. For example the auto-correlation of b5 nested into b13 (or vice versa) consists of values {0, 1, 5, 13, 65}, hence the peak to max ripple ratio is equal to 5[65/13=5].
Thus the nested code enlarges the pulse energy but does not improve the correlation properties [the PSL value].
Pulse Processing
Pulse compression is achieved by convolution of the received signal with the matched filter of the transmitted signal. This shrinks the long M-element based signal to one energetic main-lobe [which represents the auto-correlation of the shape-function and accumulates the energy of the long pulse] surrounded by side-lobes. For example, if the rectangular shape is used (see eq. 2A) together with the sequence Barker 13, b13, than the well known saw-shape appears as the result of this convolution: it contains one triangular main-lobe and six identical triangular side-lobes to the left and right of the main-lobe. The relation of the peak amplitude of the main-lobe to the peak of each side-lobe is 13/1 as it has to be when the Barker code of length 13 is used [see NATHANSON 1999, FIG. 12.2 on p 536. This example of pulse compression is shown in FIG. 3 ].
Note also that the main-lobe typically becomes wider than the original shape, as a side-effect of the matched filtering. For example, in the above example the triangle of the main-lobe occupies the time interval [−t b ,t b ], whereas the original rectangular shape-function occupies the time interval [0,t b ].
To suppress the side-lobes, mis-matched filtering is introduced [see LEVANON 2004, Section 6.6 pp. 140-142]. For this purpose an especially pre-calculated sequence, “q” of length K is used. This digital sequence is prepared such that the convolution of the original spreading sequence s with the mismatched sequence q,
g=s q
is close to a “delta function”, i.e., it has one large value (“the peak”) and all other values are small. For example, [LEVANON 2005] demonstrates that a filter that is three times longer than the original Barker 13 [i.e. a mis-matched filter of length 3*13=39] leads to a PSL ratio better than −40 dB (specifically, −43.241 dB). [NATHANSON 1999, Section 12.4 pp. 555-559] mentions that the PSL level can be reduced as low as one desires. For example, a plot for the PSL level vs. mis-matched filter length is shown in [NATHANSON 1999, FIG. 12.10, p. 557] and demonstrates PSL about −55 dB for Barker 13 and a mis-matched filter of length about 63.
Using a mis-matched filter leads to some SNR loss, which is relatively small for Barker 13 [tenths of a dB, for example just 0.2 dB according to [LEVANON 2005]]. The SNR loss may be larger for other spreading sequences [NATHANSON 1999, p. 557].
The application of very long mis-matched filters to nested binary codes is discussed in [LEVANON 2005]. For example, a mismatched filter of length 507 is applied to a 13×13 Barker nested code. The length is chosen to be three times the total length of the nested code: 507=3×3×13. The PSL attained is about −40 dB.
For the case of rectangular shape functions and nested binary codes, a special mechanism based on several digital signal processors for mismatched filtering is discussed in [NATHANSON 1999, pp. 571-573].
SUMMARY OF THE INVENTION
According to the present invention there is provided a transmitter including: (a) a pulse shaper for generating an input pulse that is a convolution of a kernel parametrized by a bit length and a spreading sequence parametrized by at least one parameter pair that consists of a spreading length and a sparsity, wherein the bit length and the at least one parameter pair form an ordered set that satisfies at least one condition selected from the set consisting of: (i) a first sparsity is different from the bit length and (ii) if the ordered set includes a plurality of the spreading lengths and the sparsities, then at least one sparsity subsequent to the first sparsity is different from a product of an immediately preceding spreading length and an immediately preceding sparsity; (b) a mechanism for transforming the input pulse to a transmitted pulse; and (c) a transducer for launching the transmitted pulse as a signal propagating in a medium.
According to the present invention there is provided a non-contact sensing device, including: (a) a transmitter that includes a pulse shaper for generating an input pulse to be transformed to a transmitted pulse that is launched as a signal that propagates in a medium towards a target, the input pulse being a convolution of a kernel parametrized by a bit length and a spreading sequence parametrized by at least one parameter pair that consists of a spreading length and a sparsity, wherein the bit length and the at least one parameter pair form an ordered set that satisfies at least one condition selected from the set consisting of: (i) a first sparsity is different from the bit length and (ii) if the ordered set includes a plurality of the spreading lengths and the sparsities, then at least one sparsity subsequent to the first sparsity is different from a product of an immediately preceding spreading length and an immediately preceding sparsity; and (b) a receiver that includes: (i) at least one transducer for coupling to the medium to receive a respective reflection of the signal from the target, (ii) for each transducer: (A) a mechanism for transforming the respective received reflection to a respective received representation of the input pulse, and (B) a pulse compressor for deconvolving the spreading sequence from the respective received representation of the input pulse, thereby providing a respective compressed pulse, and (iii) a post-processor for post-processing the at least one compressed pulse.
According to the present invention there is provided a method of transmitting a signal into a medium, including the steps of: (a) generating an input pulse that is a convolution of a kernel parametrized by a bit length and a spreading sequence parametrized by at least one parameter pair that consists of a spreading length and a sparsity, wherein the bit length and the at least one parameter pair form an ordered set that satisfies at least one condition selected from the set consisting of: (i) a first sparsity is different from the bit length and (ii) if the ordered set includes a plurality of the spreading lengths and the sparsities, then at least one sparsity subsequent to the first sparsity is different from a product of an immediately preceding spreading length and an immediately preceding sparsity; (b) transforming the input pulse to a transmitted pulse; and (c) launching the transmitted pulse into the medium as the signal.
According to the present invention there is provided a method of non-contact sensing of a target, including the steps of: (a) generating an input pulse that is a convolution of a kernel parametrized by a bit length and a spreading sequence parametrized by at least one parameter pair that consists of a spreading length and a sparsity, wherein the bit length and the at least one parameter pair form an ordered set that satisfies at least one condition selected from the set consisting of: (i) a first sparsity is different from the bit length and (ii) if the ordered set includes a plurality of the spreading lengths and the sparsities, then at least one sparsity subsequent to the first sparsity is different from a product of an immediately preceding spreading length and an immediately preceding sparsity; (b) transforming the input pulse to a transmitted pulse; (c) launching the transmitted as a signal propagating in a medium towards the target; (d) receiving at least one reflection of the signal from the target; (e) for each received reflection: (i) transforming the each received reflection to provide a respective received representation of the input pulse, and (ii) compressing the respective received representation of the input pulse by deconvolving the spreading sequence from the respective received representation of the input pulse, thereby providing a respective compressed pulse; and (f) post-processing the at least one compressed pulse.
According to the present invention there is provided a transmitter including: (a) a pulse shaper for generating an input pulse that is a convolution of a kernel and an ordered plurality of spreading sequences, wherein at least one spreading sequence subsequent to a first spreading sequence is not a binary sequence; (b) a mechanism for transforming the input pulse to a transmitted pulse; and (c) a transducer for launching the transmitted pulse as a signal propagating in a medium.
According to the present invention there is provided a non-contact sensing device, including: (a) a transmitter that includes a pulse shaper for generating an input pulse to be transformed to a transmitted pulse that is launched as a signal that propagates in a medium towards a target, the input pulse being a convolution of a kernel and an ordered plurality of spreading sequences, wherein at least one spreading sequence subsequent to a first spreading sequence is not a binary sequence; and (b) a receiver that includes: (i) at least one transducer for coupling to the medium to receive a respective reflection of the signal from the target, (ii) for each transducer: (A) a mechanism for transforming the respective received reflection to a respective received representation of the input pulse, and (B) a pulse compressor for deconvolving the spreading sequence from the respective received representation of the input pulse, thereby providing a respective compressed pulse, and (iii) a post-processor for post-processing the at least one compressed pulse.
According to the present invention there is provided a method of transmitting a signal into a medium, including the steps of: (a) generating an input pulse that is a convolution of a kernel and an ordered plurality of spreading sequences, wherein at least one spreading sequence subsequent to a first spreading sequence is not a binary sequence; (b) transforming the input pulse to a transmitted pulse; and (c) launching the transmitted pulse into the medium as the signal.
According to the present invention there is provided a method of non-contact sensing of a target, including the steps of: (a) generating an input pulse that is a convolution of a kernel and an ordered plurality of spreading sequences, wherein at least one spreading sequence subsequent to a first spreading sequence is not a binary sequence; (b) transforming the input pulse to a transmitted pulse; (c) launching the transmitted pulse as a signal propagating in a medium towards the target; (d) receiving at least one reflection of the signal from the target; (e) for each received reflection: (i) transforming the each received reflection to a respective received representation of the input pulse, and (ii) compressing the respective received representation of the input pulse by deconvolving the spreading sequence from the respective received representation of the input pulse, thereby providing a respective compressed pulse; and (g) post-processing the at least one compressed pulse.
According to the present invention there is provided a method of transmitting a signal into a medium, including the steps of: (a) selecting a desired length of an input pulse; (b) selecting a kernel and a spreading sequence, such that when the kernel is convolved with the spreading sequence without nesting the kernel in the spreading sequence, an output of the convolution is the input pulse having the desired length; (c) generating the input pulse; (d) transforming the input pulse into a transmitted pulse; and (e) launching the transmitted pulse into the medium as the signal.
According to the present invention there is provided a method of transmitting a signal into a medium, comprising the steps of: (a) generating an input pulse by convolving a kernel with a spreading sequence that is selected so that a length by which the input pulse exceeds a length of the kernel is not determined by the length of the kernel; (b) transforming the input pulse into a transmitted pulse; and (c) launching the transmitted pulse into the medium as the signal.
A first basic transmitter of the present invention includes a pulse shaper, a transformation mechanism and a transducer.
The pulse shaper generates an input pulse (either a baseband pulse or a passband pulse) by convolving a kernel with a spreading sequence. The kernel is parametrized by a bit length. The spreading sequence is parametrized by one or more pairs (preferably two or more pairs) of a spreading length and a sparsity. The bit length and the spreading sequence parameter pair(s) are an ordered set: bit length, first spreading length, first sparsity, second spreading length (if present), second sparsity (if present), etc. As described below, there are some prior art input pulses that can be generated in this manner. These prior art input pulses are excluded from the scope of the appended claims by requiring that the first sparsity be different from the bit length and/or (if there are two or more spreading sequence parameter pairs) that the second or subsequent sparsity be different from the product of the immediately preceding spreading length and the immediately preceding sparsity.
The transformation mechanism transforms the input pulse to a transmitted pulse. If the input pulse is a passband pulse then the transformation mechanism includes a digital-to-analog converter. If the input pulse is a baseband pulse then the transformation mechanism includes a modulator for modulating a carrier wave with the baseband pulse.
The transducer launches the transmitted pulse as a signal propagating in a medium that supports such propagation.
Preferably, the spreading sequence is a convolution of a plurality of spreading functions, with each spreading function being parametrized by a respective spreading sequence parameter pair. For example, if the spreading sequence is the inverse z-transform of the spreading filter product b 5 (z 25 )b 13 (z 129 ) discussed below, the first spreading function, the inverse z-transform of b 5 (z 25 ), is parametrized by a spreading length of 5 and a sparsity of 25, and the second spreading function, the inverse z-transform of b 13 (z 129 ), is parametrized by a spreading length of 13 and a sparsity of 129. Note that this spreading filter product, and hence the associated spreading sequence, satisfies the condition that the second sparsity be different from the product of the first spreading length and the first sparsity: 5×25=125≠129.
Most preferably, the pulse shaper generates the input pulse by a plurality of convolutions equal in number to the plurality of spreading functions. The first convolution is of the kernel with the first spreading function. Each subsequent convolution is of the output of the immediately preceding convolution with the next spreading function. For example, if the spreading sequence is the inverse z-transform of the spreading filter product b 5 (z 25 )b 13 (z 129 ) the first convolution is of the kernel with the inverse-z-transform of b 5 (z 25 ) and the second convolution is of the output of the first convolution with the inverse z-transform of b 13 (z 129 ).
In some embodiments, the signal is an electronic signal. In other embodiments, the signal is an acoustic signal.
A first basic non-contact sensing device of the present invention includes a transmitter and a receiver. The transmitter includes at least the pulse shaper as described above for generating an input pulse to be transformed to a transmitted pulse that is launched as a signal towards a target via a medium in which the signal propagates. The receiver includes one or more transducers with associated respective transformation mechanisms and pulse compressors and a post-processor. The transducer(s) is/are for coupling to the medium to receive (a) (respective) reflection(s) of the signal from the target. Each demodulator demodulates its received reflection to provide a received representation of the input pulse. Each pulse compressor deconvolves the spreading sequence from its representation of the input pulse to provide a compressed pulse. The post-processor post-processes the compressed pulse(s). Depending on how the device is configured, the post processing could include obtaining (a) travel time(s) from the transmitter to the transducer(s) via the target and inferring a range to the target from the travel time(s); and additionally or alternatively obtaining a direction of arrival of the received reflection(s).
If, as is preferred, the spreading sequence is a convolution of a plurality of spreading functions, with each spreading function being parametrized by a respective parameter pair, then each pulse compressor deconvolves the spreading sequence from its representation of the input pulse by a plurality of deconvolutions equal in number to the plurality of spreading functions. The first deconvolution is of the last spreading function from the representation of the input pulse. Each subsequent deconvolution is of the preceding spreading function from the output of the immediately preceding deconvolution. Most preferably, each deconvolution is effected using a respective key whose sparsity is equal to the sparsity of the spreading sequence being deconvolved. Such sparse deconvolutions are highly efficient.
In some embodiments, the signal is an electronic signal. In other embodiments, the signal is an acoustic signal.
In some embodiments, the pulse compressor(s) use(s) (a) matched filter(s) to deconvolve the spreading sequence from the representation(s) of the input pulse. In other embodiments, the pulse compressor(s) use(s) (a) mismatched filter(s) to deconvolve the spreading sequence from the representation(s) of the input pulse.
A first method of transmitting a signal into a medium includes generating an input pulse as described above in the context of the first basic transmitter of the present invention, transforming the input pulse to a transmitted pulse, and launching the transmitted pulse into the medium as the signal.
A first method of non-contact sensing of a target performs the first method of transmitting a signal to launch the signal towards the target. Then the method receives one or more reflections of the signal from the target. The received reflection(s) is/are transformed to (a) (corresponding) received representation(s) of the input pulse. The representation(s) of the input pulse is/are compressed, by deconvolving the spreading sequence from the representation(s) of the input pulse, to provide (a) compressed pulse(s). The compressed pulse(s) are post-processed to obtain a range to the target and/or a direction of arrival of the reflection(s) from the target.
A second basic transmitter of the present invention also includes a pulse shaper, a transformation mechanism and a transducer.
The pulse shaper generates an input pulse by convolving a kernel with an ordered plurality of spreading sequences. As described below, there are some prior art input pulses that can be generated in this manner. These prior art input pulses are excluded from the scope of the appended claims by requiring that at least one of the spreading sequences subsequent to the first spreading sequence be non-binary. In the prior art, such convolution of spreading sequences is successive nesting of the first spreading sequence in the second spreading sequence, of the nested first and second spreading sequences in the third spreading sequence, etc., and such nesting of a source sequence in a target sequence is defined only for a binary target sequence. A “binary” sequence is a sequence, all of whose members take on one of only two values. Usually these values are “−1” and “1”.
The transformation mechanism transforms the input pulse to a transmitted pulse. If the input pulse is a passband pulse then the transformation mechanism includes a digital-to-analog converter. If the input pulse is a baseband pulse then the transformation mechanism includes a modulator for modulating a carrier wave with the baseband pulse.
The transducer launches the transmitted pulse as a signal propagating in a medium that supports such propagation.
A second basic non-contact sensing device of the present invention includes the pulse shaper of the second basic transmitter of the present invention, and otherwise is identical to the first basic non-contact sensing device of the present invention.
A second method of transmitting a signal into a medium includes generating an input pulse as described above in the context of the second basic transmitter of the present invention, transforming the input pulse to a transmitted pulse, and launching the transmitted pulse into the medium as the signal.
A second method of non-contact sensing of a target performs the second method of transmitting a signal to launch the signal towards the target, and subsequently is identical to the first method of non-contact sensing of the target.
As described below, the non-contact sensing devices of the present invention could be, for example, radar remote sensing devices, acoustic remote sensing devices, medical ultrasound devices or seismic exploration devices. Such medical ultrasound devices are “non-contact” sensing devices in the sense that the transducers of the devices are coupled to the skin of a patient whereas the targets of the sensing are organs and tissues that are not in contact with the skin of the patient.
Normally, a non-contact sensing device of the present invention that measures DOA includes a plurality of transmitters and/or receivers so that DOA can be determined by standard methods such as beamforming.
The first method of transmitting a signal into a medium is a special case of a more general method, in which a desired length of an input pulse is selected and then a kernel and a spreading sequence are selected, such that when the kernel is convolved with the spreading sequence without nesting the kernel in the spreading sequence, the output of the convolution is the input pulse that has the desired length. In the context of the first method of transmitting a signal into a medium, changing the sparsities of the spreading sequences changes the length of the input pulse. The input pulse is generated and transformed into a transmitted pulse that is launched into the medium as the signal. Preferably, the spreading sequence is parametrized by one or more sparsities.
From another point of view, this method generates an input pulse of a desired length by convolving a kernel with a spreading sequence that is selected so that the length by which the input pulse exceeds the length of the kernel is not determined by the length of the kernel, as it would be if the convolution merely nested the kernel in the spreading sequence.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments are herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIGS. 1 and 2 illustrate the transmission of acoustic signals inside a silo.
FIG. 3 shows the results of pulse compression of the Barker 13 code by matched filtering;
FIG. 4 is an overview of multi-layer signal construction and processing;
FIG. 5 is an example of a kernel;
FIGS. 6 and 7 show pulse construction by convolving the kernel of FIG. 5 with sparse sequences constructed from Barker 5 with a sparsity of 25 and from Barker 13 with a sparsity of 129;
FIGS. 8-10 illustrate deconvolutional compression of the pulse constructed in FIGS. 3-5 ;
FIGS. 11 and 12 show pulse construction by convolving the kernel of FIG. 5 with sparse sequences constructed from Barker 5 with a sparsity of 7 and from Barker 13 with a sparsity of 41;
FIGS. 13 and 14 show systems of the present invention for measuring a range to a target in a propagation medium.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles and operation of ranging and direction-finding signals according to the present invention may be better understood with reference to the drawings and the accompanying description.
Referring again to the drawings, the principle of multi-layer signal construction and processing is shown in FIG. 4 .
The present invention uses multi-layer signal construction with an arbitrary number N of layers, including the specific cases of N=1 [only one layer], N=2 [two layers], N=3 etc. A particular important case of just two layers is what is shown in FIG. 4 .
The following discussion focuses on digital version of the signal. This is possible due to the frequency range of acoustic range and direction finders such as are used in U.S. Ser. No. 10/571,693. The acoustic signals typically occupy the frequency range of several kilohertz; hence digital oversampling can be easily applied. Such oversampling may be performed at frequencies of tens of kilohertz.
General Discussion
The ranging and direction finding pulse construction and processing of the present invention first is described in general terms/language. The precise mathematical description and comparison to the prior art techniques follows below.
Transmitter Processing
0 th layer. use a short-in-time kernel (the term “kernel” is defined below in the Mathematical Description section) that satisfies the bandwidth restrictions.
1 st layer. convolve the kernel with a spreading sequence that is either itself a convolution of several spreading functions or just one short or long spreading function to increase the SNR. The case of several spreading functions is a “multi-layered” design.
Every spreading function has its own spreading factor, which can be small or large. Spreading factors govern the efficiency of the design as well as the total signal length in time.
First Receiver Processing: Deconvolution
Remove all the spreading functions by using de-convolution filters: this increases the SNR. These filters also are called keys herein, since they open the spreading functions. To not increase the noise, the keys are scaled to have unit norm for their total convolution. The spreading factor of a key is exactly the same as of its corresponding spreading function. This processing results in obtaining back the original kernel (thus short in-time) having enlarged SNR and flanked by some small ripples. The ripples may be diminished to any value by using longer keys, if desired.
Second Receiver Processing: Kernel Post-Processing
The recovered kernel can be further post-processed. For example, one of the possible ways includes standard. Matched Filtering (having the best SNR, but not the best resolution), filtering using a Wiener filter, or application of a filter that filters out the noise frequency in the silo, or any other possible means. The post-processing can be done also in many ways which are well-known in the art and so need not be elaborated here. This post-processing is usually aimed at estimation of TOA [Time of Arrival] and/or DOA [Direction of Arrival] of the pulse. Methods for DOA or TOA estimation are well-known in the art and so are not elaborated here. For example, U.S. Ser. No. 10/571,693 uses beamforming.
Mathematical Description and Comparison with Prior Art
Construction of the Transmitted Signal
The signal is constructed by convolving a kernel whose z-transform is a kernel shape S(z) and several cascaded spreading functions (N functions) whose z-transforms are spreading filters F k (z D k ), each of which has its own sparsity D k . In the z-transform domain, this convolution is multiplication:
sig ( z )= S ( z )· F 1 ( z D 1 )· F 2 ( z D 2 )· . . . · F N ( z D N ) (eq. 3.1)
The signal, if desired, can be back-scaled to unit amplitude before the final D/A [Digital to Analog] conversion and amplification.
Scaling [e.g. to unit amplitude] may be performed at the final stage [leading to the smallest quantization error], as follows:
scaled_sig [ n ] = sig [ n ] max ( sig ) ( eq . 3.2 )
(in the time domain) for every time sample “n”, or at any cascade stage, depending upon the specific realization.
The kernel has to be as short in time as possible to deliver good resolution in time. The kernel length is only limited by the bandwidth constraint requirements of the (acoustic) hardware [since short-in-time signals are wide in frequency]. The shortness in time of the kernel also significantly improves the ability to recognize (and also not to miss) the target point reflection by reducing the interference between reflected signals.
The spreading filters F k (z D k ) can be based upon any digital sequence. Such a sequence may be any real-valued or complex-valued sequence. As a particular case, such a sequence can be binary and in particular may be based on Barker sequences or on other sequences with coefficients ±1 (e.g. the Littlewood polynomials).
The spreading filters and the sparsities D k govern the total length of the signal and the pulse energy.
The convolution of the kernel with the spreading sequence can be performed in many ways. For example:
(i) directly: The kernel is convolved with the entire multi-layer spreading sequence, which typically is long (its length is equal to the total pulse length minus the kernel length plus one) and has an irregular sparse structure (different numbers of zeros between successive non-zero elements).
(ii) layer by layer, convolving the output of each layer except the last layer with the next spreading function. This approach uses only short and sparse spreading functions to perform the convolutions and thus is computationally efficient. For example, in FIGS. 5-7 below this approach is used to create a pulse with 1703 samples by using a kernel of length 55 and two sparse functions, one with five non-zero elements and the other with thirteen non-zero elements. The output of the first layer is relatively short, having a length of only 155 samples. This makes the convolution of the output of the first layer with the second spreading function (which has a very large sparsity of 129 and only thirteen non-zero elements) especially efficient. In that example, the layers are applied in order of increasing sparsity. It also is possible to perform an exhaustive search to find the most computationally efficient layer order. Note that the number of possible designs for N layers is N! For a typical design of two layers there are just two variants to compare. With three layers there are six variants to compare.
Note the difference of the signal construction of the present invention from the conventional signal construction. As an example, observe the single layer construction. In the prior art design, the separation of the “bits” [or the spreading coefficients s m ] and the shape of the kernel are governed by just one and thus the same parameter, t b . Typically, t b corresponds to length of the shape as it is observed for the rectangular shape of (eq. 2A), or corresponds to the time interval from the peak value to the first zero-crossing as for the Gaussian-windowed sine function of (eq. 2B).
For non-rectangular shapes and/or non-binary spreading sequences the usage of the same parameter for the spreading coefficients separation and for the shape function may lead to non-optimal energy of the resulting constructed signal.
Thus the sparsity set {D 1 , . . . , D n } [or the single parameter D 1 , in the simplest one-layer case] may be used [as parameters or degrees-of-freedom] for energy maximization of the constructed signal.
The sparsity set {D 1 , . . . , D N } also governs the total length of the signal. The analytical relation for the pulse length is given by (eq. A2) of Appendix A. This is a very important property and it addresses challenge i-2 above, the need of pulses of different lengths for acoustic ranging and direction finding pulses, in particular in silo applications. Recall that this requirement follows from the fact that the upper surface of the silo contents is dynamic and may change its distance from the ceiling of the silo during the silo operation from several tens of centimeters to several tens of meters and back.
Energy maximization of the signal can be also done under signal length constraint. Signal energy maximization subject to signal length constraint can be done by several methods, including an exhaustive search over sparsities.
In the prior art, the parameter of the kernel implicitly defines the bandwidth of the kernel, for example
G ( f ) = sin 2 ( π ft b ) ( π ft b ) 2
for the rectangular pulse kernel of (eq. 2A), or for the sharper spectrum of the kernel of (eq. 2B), just as this parameter defines the time-spacing between the spreading coefficients. In contrast, the design of the present invention has the advantage of making no connection between the spectrum kernel requirements and the sparsities: the kernel shape has to be chosen to satisfy the frequency constraints, while the sparsities are degrees of freedom that satisfy other requirements for the pulse, such as those mentioned above.
Note that if the spreading filters are chosen to have good autocorrelation properties, this usually implies that their spectra are relatively flat, and thus they preserve the same flatness for any value of the sparsities. This also simplifies the pulse design procedure, since it allows designing the kernel and the spreading filters separately.
Comparison of the Signal Design of the Present Invention with the Prior Art
The innovative method of using sparse spreading filters that is presented herein is considerably more general than the nested or concatenated Barker or other binary codes of the Prior Art. The method presented herein also includes these codes as special cases.
First, the nesting of the prior art essentially implies the usage of binary sequences, for although a binary sequence may be “nested” into other binary sequence; the nesting of a sequence into a non-binary sequence is not defined, while in the signal construction of the present invention any arbitrary [and thus not necessarily binary] sequence may be used for the spreading filters.
Second, the nesting operation demands an exact rigid set of sparsity parameters with no overlapping allowed. Contrary to this rigidity, the signal construction of the present invention may use any set of sparsity parameters.
Thus, while the conventional pulse construction uses nesting, the present invention uses sparse convolution, which is considerably more general and can be applied to any type of sequence and places no restrictions upon the sizes of the used sequences.
The following example demonstrates that the nested codes are a particular case of sparse spreading filters. Consider Barker 5 and Barker 13. The nesting of Barker 5 into Barker 13 also may be done by convolution, or by z-transform, as:
nested_code — 5×13( z )= b 5 ( z ) b 13 ( z 5 )[the length is 5×13=65]
In general, to nest a binary sequence whose z-transform is a(z) in another binary sequence whose z-transform is b(z), sparse convolution may be used, as follows:
nested — axb ( z )= a ( z ) b ( z L a )
Here, L a is the length of the sequence whose z-transform is a(z). In the above example, a(z) is Barker 5 and L a =5. Note that the length of the nested construction above is given by the product of the lengths of its components: if L b is the length of the sequence whose z-transform is b(z) then the length of the sequence whose z-transform is nested_axb(z) is L a L b .
Consider, now, as an example, the nesting of a rectangular kernel that consists of D consecutive 1's. The kernel shape is
S ( z ) = rec ( z , D ) = 1 + … + z - ( D - 1 ) = ∑ k = 0 D - 1 z k
The sparsity D must be inserted into the nested code to construct the sparse nested code
F ( z )=sparse_nested_code( z )=nested_code — 5×13( z D )= b 5 ( z D ) b 13 ( z 5D )
Hence, the spreading filters for this nested Barker code are F 1 (z)=b 5 (z) and F 2 (z)=b 13 (z) and the signal is constructed in the z-transform domain as
sig ( z )= rec ( z,D )· F 1 ( z D )· F 2 ( z 5·D )
The length of the corresponding time sequence is D×5×13 samples. A general code may be written as:
sig ( z )= S ( z,D )· F ( z )= rec ( z,D )· b 5 ( z D 1 )· b 13 ( z D 2 )
This general code has parameters {D, D 1 , D 2 } and is much richer than the nested code that has only one parameter, D. The spreading sequences of the present invention represent sparse nested sequences only for a very specific relationship of the sparsities: 5D 1 =D 2 for sparse b 5 to be nested into sparse b 13 or 13D 1 =D 2 for sparse b 13 to be nested into sparse b 5 . For example, the spreading filter product b 5 (z 25 )b 13 (z 129 ) does not represent a sparse nested code.
Even in the cases where the sparsity parameters of the sparse filters are related such that sparse convolution [when applied to binary sequences] brings the same result as the nested code, the pulse construction of the present invention still has the sparsity of the sparse nested code [e.g. D 1 in the example b 5 (z D 1 )b 13 (z 5·D 1 )] independent of the kernel length that is used [e.g., D in the above example]. This thus allows optimization for total pulse length and/or pulse energy by varying this parameter, as a degree of freedom. This is an essentially new element which was not present in the prior art.
Also recall that in the prior art, changing “t b ” [or the bit length L b =t b /T s ] simultaneously changes the spectrum of the signal, which may be undesirable or even prohibited for some applications.
The appended claims explicitly exclude the special prior art cases from their scope. These prior art cases are described as signals constructed from convolution of a kernel (rectangular or non-rectangular), parametrized by the bit length parameter L b , with a sparse spreading sequence whose sparsity is equal to L b . As an example of a non-rectangular kernel the Gaussian-windowed sine function of equation 2B has a length equal to 4·L b since it has support [−2t b ,2t b ] but its bit length is L b .
For example, the signal constructed by nesting a rectangular kernel of length L b into Barker 5,
sig ( z )= rec ( z,L b ) b 5 ( z L b )
is excluded. Concerning the multi-stage signal construction, the prior art is restricted to nesting of a rectangular kernel of length L b into sparse (with resulting sparsity L b ) nested binary sequences. For example, sparse nesting of Barker 5 into Barker 13, convolved with a rectangular pulse of length L b ,
sig ( z )= rec ( z,L b )· b 5 ( z L b ) b 13 ( z 5·L b )
is excluded.
First Receiver Processing: Deconvolution of the Layers
The received signal, rx_sig(z) in the z-transform domain, is processed with the de-convolution filters K k (z D k ), which also are called keys herein. Each key has its own sparsity which equals, and so corresponds exactly to, the sparsity of the corresponding spreading filter. The resulting deconvolved signal, in the z-transform domain, is:
dsig ( z )= rx — sig ( z )· K 1 ( z D 1 )· K 2 ( z D 2 )· . . . · K N ( z D N ) (eq. 3.3)
In this relation, K m (z) is a [non-sparse] mis-matched filter for the [non-sparse] spreading filter F m (z). This mis-matched filter serves as a template.
From Appendix B, it follows that a sparse spreading filter, K m (z D m ) with any sparsity D m , is the mis-matched filter for F m (z D m ). This explains equation (eq. 3.1).
Denoting the length of the template for the mis-matched filter as
L m =length( F m ( z ))
then the sparse mis-matched filter has length
length( F m ( z D m ))=1+( L m −1)· D m
For sparsities of 100 or more this leads to very long filters [see also the example below]. However, despite their extremely long lengths, these filters have small numbers (L m ) of non-zero coefficients. Thus the sparsity leads to high computational efficiency, when the filter is applied. The storage of such filters is also very, convenient, since only the template of length L m has to be stored.
Many scalings are possible. The following is one of them: one may assume that these filters are scaled in such a way as to result in no amplification of the white noise:
norm ( K 1 ( z D 1 )· K 2 ( z D 2 )· . . . · K N ( z D N )=1 (eq. 3.4)
After the de-convolution by the keys, the resulting dsig(z) is very close to the original scaled kernel shape S(z). This means that relative to S(z), disig(z) is scaled, shifted in time by some delay and has some insignificant small ripples around it. dsig(z) has increased SNR [relative to rx_sig(z)]. (see Appendix 13 for discussion of delay and gain calculations).
As an example, consider a non-nested pair of sparse spreading filters b 5 (z 25 )b 13 (z 129 ) used for pulse construction. To de-convolve these spreading filters we use the following pair of Keys: K 5 (z 25 )K 13 (z 129 ), where K 5 (z) is the mismatched filter to b 5 (z) and K 13 (z) is the mismatched filter to b 13 (z). Assume, just as an example, that the filter K 5 (z) has 24 elements and that the filter K 13 (z) has 42 elements, to obtain a PSL level of about −40 dB. The construction of the mis-matched filters is known in the prior art and so need not be elaborated here. Total length of the mis-matched filter is prohibitive if the mis-matched filter has to be directly calculated and processed: (23*25+41*129)+1=5865 elements. Note also that such large filters may demand very large resolution in bits. However, a filter with only 42 non-zero elements has to be applied first [the application of K 13 (z 129 ) and a filter with only 24 non-zero elements has to be applied after it [the application of K 5 (z 25 ). This indeed gives a very effective sparse layer-by-layer de-convolution.
Second Receiver Processing: Kernel Post-Processing
As mentioned above, the resulting dsig(z) corresponds to the original scaled kernel shape S(z) at some total delay D [see (eq. C2)] flanked by some negligible ripples [see (eq. C1)].
The next step is the processing of the kernel. This step may be performed in many different ways and which are not elaborated herein. The kernel processing is a separate art. What is important here, is that any known or developed method may be applied now to the kernel processing.
The problem of pulse processing thus is split by the present invention into two steps: the first is the de-convolution of the long ranging pulse by using sparse key filters, resulting in a short-in-time kernel with an enlarged SNR, and the second step is the further processing of this kernel.
Just as an example, linear processing can be chosen. Linear processing is represented in the z-transform domain by a multiplication of dsig(z) from the first step by some filter M(z):
out( z )= dsig ( z )· M ( z ) (eq. 3.5A)
Here, for example, one may use the matched filter of the kernel shape as an option for the filter M(z):
M ( z )=MF[ S ( z )]] (eq. 3.5B)
One may also use conventional Weiner filtering.
The filtering operation may be done in the time domain by time-convolution, or in the z-transform domain by multiplication, as it is known to those skilled in digital signal processing.
While the matched filtering or the Wiener filtering are well-known established techniques, the innovation here is that these filtering operations are applied to just the recovered kernel and not to the whole received signal. Among other advantages, the is present partitioning between, the deconvolution of the spreading filters and the deconvolution of the kernel avoids the use of the long mismatched filters of [LEVANON 2005] that are mentioned in the Field and Background section.
The filter M(z) can also incorporate knowledge about the noise distribution in the acoustic environment [e.g. in the silo] to filter out the most dominant noise frequencies [e.g. low frequencies in the silo environment].
EXAMPLES
For the kernel shown in FIG. 5 , a two-layered design, based upon the two spreading functions sparse Barker 5 sequence with a sparsity of 25 and sparse Baker 13 sequence with a sparsity of 129, is presented. These two spreading functions have, respectively, only five and thirteen non-zero elements. This makes the layered convolution pulse construction very efficient. The corresponding spreading filters are F 1 =b 5 (z 25 ) and F 2 =b 13 (z 129 ). The first layer of pulse construction represents convolution of the kernel with the sparse spreading filter F 1 and is shown in FIG. 6 . The second layer represents convolution of the first layer with the sparse spreading filter F 2 and is shown in FIG. 7 . Note that at every pulse construction stage the amplitude is scaled to have unit absolute maximal value.
Denote the length as “L” samples, energy as “E” [the sum of the squares of the amplitudes], and power as “P”, P=E/L. The signal is scaled to the maximal unit amplitude at every stage. Then for this example:
0 th stage: the kernel alone: L=55, E=11.582, P=0.21
1 st stage, layer 1: L=155 samples, E=54.617, P=0.35
2 nd stage, layer 2: L=1703 samples, E=710.03, P=0.417
The maximal power of any sine-modulated shape [having its maximal amplitude limited to 1] is P=0.5, which represents the upper limit for the power. In this example, both the energy of the pulse and the power of the pulse increase at every stage of the pulse design.
The first stage of the receiver processing including two layers of de-convolution for this two-stage design is further shown in FIGS. 8 and 9 . The resulting kernel is shown in FIG. 10 . This Kernel is identical [up to the scaling due to increased gain] to the initial Kernel flanked by some small ripples.
Another example is based upon the kernel of FIG. 5 but using shorter sparse spreading sequences. The corresponding spreading filters are F 1 =b 5 (z 7 ) and F 2 =b 13 (z 41 ). The first stage of pulse construction is shown in FIG. 11 , and the second stage is shown in FIG. 12. The final pulse length is given by (eq. B2): L=55+4*7+12*41, which leads to L=575. The pulse constructed in this manner is shorter than the pulse of FIG. 7 . This is achieved by using smaller values of the sparsity parameters: 7 and 41 instead of 25 and 129.
System
FIG. 13 illustrates a range and direction finding system 40 of the present invention. System 40 includes a transmitter 10 and a receiver 20 . Transmitter 10 in turn includes a pulse shaper 12 , a modulator 14 and a transducer 16 . Receiver 20 in turn includes a transducer 22 , a demodulator 24 , a pulse compressor 26 and a post-processor 28 . Pulse shaper 12 generates a baseband pulse from a kernel as described above. Modulator 14 modulates a carrier wave with the baseband pulse. Transducer 16 launches the modulated carrier wave, into a medium 30 that supports propagation of the carrier wave, as a transmitted signal 34 , towards a target 32 . Transmitted signal 34 is reflected from target 32 as a reflected signal 36 that is received by transducer 22 . Demodulator 24 demodulates the received reflection to provide a received representation of the baseband pulse. What is demodulated by demodulator 24 is only a representation of the baseband pulse because it is not identical to the baseband pulse, having been distorted e.g. by propagation noise in medium 30 . Pulse compressor 26 compresses the representation of the baseband pulse by deconvolution as described above. The pulse compression provides a compressed pulse that is a time-shifted representation of the original kernel. Post-processor 28 applies post-processing as described above to the compressed pulse and infers the range to target 32 as one-half of the product of the round-trip travel time of signals 34 and 36 and the propagation speed of signals 34 and 36 in medium 30 .
System 40 as drawn is, strictly speaking, a ranging system, not a range and direction finding system. A true ranging and direction finding system would include several transmitters 10 and/or several receivers 20 , and the post-processing would include DOA determination, for example by beamforming, as in U.S. Ser. No. 10/571,693.
In radar applications, signals 34 and 36 are radio-frequency electromagnetic signals, medium 30 typically is free space, and transducers 16 and 22 are antennas. In applications such as lidar that use optical frequencies, signals 34 and 36 are optical-frequency electromagnetic signals, medium 30 typically is free space, transducer 16 typically is a laser or a light-emitting diode, and transducer 22 is a photodetector. In acoustic ranging applications, signals 34 and 36 are acoustic signals, medium 30 typically is a gas such as air or a liquid such as water or a mixture thereof such as a foam, transducer 16 is a speaker and transducer 22 is a microphone. In medical ultrasound applications, signals 34 and 36 are ultrasound signals, medium 30 is biological tissue, and transducers 16 and 22 typically are piezoelectric transducers. In seismic exploration, signals 34 and 36 are seismic signals, medium 30 is the Earth, transducer 16 typically is a seismic vibrator and transducer 18 is a geophone.
FIG. 14 illustrates another range and direction finding system 80 of the present invention. System 80 includes a transmitter 50 and a receiver 60 . Transmitter 50 in turn includes a pulse shaper 52 , a digital-to-analog converter 54 and a transducer 56 . Receiver 60 includes a transducer 62 , an analog-to-digital converter 64 . a pulse compressor 66 and a post-processor 68 . Pulse shaper 52 generates a passband pulse from a kernel as described above. Digital-to-analog converter 54 converts the passband pulse to an analog transmitted pulse. Transducer 56 launches the transmitted pulse into a medium 70 as a transmitted signal 74 toward a target 72 . Like medium 30 , medium 70 supports propagation of signal 74 . Signal 74 is reflected from target 72 as a reflected signal 76 that is received by transducer 62 . Analog-to-digital converter 64 converts the received reflected signal to a digital received representation of the passband pulse. Similar to the output of demodulator 24 of system 40 , the output of analog-to-digital converter 64 is only a representation of the passband pulse because it is not identical to the passband pulse, having been distorted e.g. by propagation noise in medium 70 . Pulse compressor 66 compresses the representation of the passband pulse by deconvolution as described above. The pulse compression provides a compressed pulse that is a time-shifted representation of the original kernel. Post-processor 68 applies post-processing as described above to the compressed pulse and infers the range to target 72 as one-half of the product of the round-trip travel time of signals 74 and 76 and the propagation speed of signals 74 and 76 in medium 70 .
System 80 as drawn is, strictly speaking, a ranging system, not a range and direction finding system. A true ranging and direction finding system would include several transmitters 50 and/or several receivers 60 , and the post-processing would include DOA determination, for example by beamforming, as in U.S. Ser. No. 10/571,693.
Concluding Remarks
One important feature of the input pulse of the present invention is that the extend to which the length of the input pulse (in time, or in distance after multiplying the length in time units by the propagation speed (e.g. the speed of light for radar pulses) or in numbers of samples) exceeds the length of the kernel is not determined by the length of the kernel. This is in contrast to the prior art, in which nesting the kernel in a spreading sequence necessarily produces an input pulse whose length is an integral multiple of the length of the kernel. (eq. A2) in Appendix A below gives the length L of the input pulse in terms of the length L 0 of the kernel and the lengths L i and sparsities D i , i=1, . . . , k) of k spreading sequences. The extent to which L exceeds L 0 is determined by the L i and the D i , parameters that clearly are independent of L 0 .
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. Therefore, the claimed invention as recited in the claims that follow is not limited to the embodiments described herein.
APPENDIX A: CONSIDERATIONS OF TOTAL PULSE LENGTH
The length of the pulse given by (eq. 3.1) and constructed by N convolutions is:
L =length( S )+length( F 1 ( z D 1 ))+ . . . +length( F N ( z D N ))− N
Denoting the length of the templates [i.e. the spreading filters having unit sparsity D=1]:
L 0 =length( S ), L k =length( F k ( z )) (eq. A1)
and since
length( F k ( z D k k ))=1+( L k −1)· D k
to the following is obtained:
L=L 0 +( L 1 −1)· D 1 + . . . +( L k −1)· D k (eq. A2)
For example, for a kernel of length 55 samples and for any spreading functions having templates of length 5 and 13, the pulse length is: L=55+4*D 1 +12*D 2 . The length in samples can be further re-calculated to the length of the pulse in meters. Denoting the speed of wave propagation as “c” and the sampling rate as “F s ”,
L
meters
=
c
F
s
L
samples
(
eq
.
A
3
)
If the ranging target is the contents of a silo and the minimal distance to the upper surface of the contents of the silo is R [meters], then the signal length has to be twice this value because the signal has to go forth and back. This leads to the constraint:
L samples < 2 F s c R ( eq . A 4 )
which in turn leads to the constraint for the pulse design:
L
0
+
(
L
1
-
1
)
·
D
1
+
…
+
(
L
k
-
1
)
·
D
k
<
2
F
s
c
R
(
eq
.
A
5
)
Just as an example, for the speed of sound being about 340 m/s and the digital sampling rate of 41,000 Hz, which is close to the sampling rate used for compact disks, L samples is less than (2*41000/340)*R, or, approximately, L samples <241*R. Hence for a distance to the upper surface of the silo contents of about 0.4 meters the maximal possible length is about 96 samples, while for a distance of 10 meters the maximal possible length is about 2410 samples.
Finally, note that the two pulses [one longer and one shorter], presented in the above two-layer construction example, and having 1703 samples and 575 samples, may be applied to the case of the target surface being at a distance [or for surfaces situated farther than this distance] of 1703/41000*340/2=7.06 meters and 575/41000*340/2=2.4 meters, while the kernel of length 55 samples corresponds to a distance of 55/41000*340/2=0.23 meters.
APPENDIX B: MISMATCHED FILTER FOR A SPARSE FILTER
The convolution of two filters in the time domain is exactly represented in the z-transform domain by multiplication of two corresponding polynomials. Assume that for F(z) we know [from the prior art] how to construct K(z) such that
P ( z )= F ( z )· K ( z )
has a delta-like behavior, i.e. its inverse z-transform has one large coefficient and all the other coefficients are small. Then, by change of variables z to z D another polynomial is created:
P ( z D )= F ( z D )· K ( z D )
that has exactly the same non-zero coefficients [in addition to many newly emerged zero coefficients] and therefore the new polynomial has exactly the same MAX to PEAK ratio, i.e., the same PSL as the first polynomial. Therefore, if K(z) is the mismatched filter for F(z), then K(z D ) is the mismatched filter of the same quality [i.e. having the same PSL] for F(z D ) for any value of D.
APPENDIX C: CALCULATION OF THE TOTAL DELAY AND THE PROCESSING GAIN
To calculate the total delay, assume that the templates (thus with unit sparsity) behave as (“s.r.” means small [insignificant] ripples):
F 1 ( z )· K 1 ( z )≈ G 1 z −d 1 +s.r., . . . , F N ( z )· K N ( z )≈ G N z −d N +s.r. (eq. C1)
Then the sparse de-convolution for the pulse constructed by (eq. 3.1) is:
dsig ( z )= rx — sig ( z )· K 1 ( z D 1 )· K 2 ( z D 2 )· . . . · K N ( z D N )
which is (eq. 3.3). Assuming that the received signal rx_sig(z)=A·sig(z)+noise, and ignoring small ripples of the mismatched filters as well as ignoring the noise term as not relevant for delay calculations, gives [after grouping the sparse spreading filters with the corresponding keys]:
dsig ( z )≈ A·S ( z )·{ F 1 ( z D 1 )· K 1 ( z D 1 )}· . . . ·{ F N ( z D N )· K N ( z D N )}
Finally, applying (eq. C1) gives:
dsig ( z ) ≈ A · S ( z ) · G 1 z - d 1 · D 1 · … · G N z - d N · D N = A · ( ∏ k = 1 N G k ) · S ( z ) · z - ∑ k = 1 N d k · D k
This corresponds to the delayed original kernel shape with the new gain. The total delay is calculated as
D _total=deconvolution_delay=Σ k=1 N d k ·D k (eq. C2)
and the gain increase is equal to the product of the deconvolution gains:
Processing_gain_in_dB=20·log 10 (Π k=1 N G k ) (eq. C3)
Recall that the mismatched filters are to be scaled to not amplify the white noise after their joint application, i.e. according to (eq. 3.4). | To generate a pulse for ranging, a kernel is convolved with a spreading sequence. The spreading sequence is parametrized by one or more ordered (length, sparsity) pairs, such that the first sparsity differs from the bit length of the kernel and/or a subsequent sparsity differs from the product of the immediately preceding length and the immediately preceding sparsity. Alternatively, a kernel is convolved with an ordered plurality of spreading sequences, all but the first of which may be non-binary. The pulse is launched towards a target. The reflection from the target is transformed to a received reflection, compressed by deconvolution of the spreading sequence, and post-processed to provide a range to the target and/or a direction of arrival from the target. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mat bevel cutting apparatus and more particularly to an apparatus which is particularly designed and constructed to facilitate the entire preparation of matting material for picture framing from the step of sizing the material to the completed bevel cut for framing the picture.
2. Description of the Prior Art
One of the primary problems confronting a frame shop technician is the preparation of mats for use in outlining a picture to be framed. There are machines presently available which are both complicated and costly for the preparation of some mats but are normally prohibitively expensive for the individual frame shop owner. Therefore, most frame shop owners utilize some rough makeshift device for cutting the mats or are forced to accomplish the entire operation by means of a knife blade and straight edge.
The art of mat cutting is old as is evidenced in the patent to McCall, U.S. Pat. No. 570,180, issued 1896 for a "Bevel Edge Cardboard Cutter". The patent to McCall recognized that there is a problem in holding down the matting material during the cutting operation and therefore mounted his cutting guide rail pivotally so that the guide rail itself could help hold down the matting material. However, by pivotally mounting his guide rail mechanism, he was foreclosed from incorporating sidewalls for the purpose of aligning and squaring the matting material within the machine.
The problem pointed out in the above description of the patent to McCall has been prevalent throughout the manufacturing of bevel picture mat cutters. Further, most devices that have been manufactured or are presently available have a rather complicated measuring apparatus built-in or the measuring has to take place by an ordinary scale and the use of a marking apparatus to mark the cutting points on the mat itself. The more recent patent to Ellerin, U.S. Pat. No. 3,527,131, issued 1970 for a "Mat Cutter" is indicative of the complicated measuring and blade guide apparatuses which are presently available on the market.
SUMMARY OF THE INVENTION
The present invention is particularly designed and constructed for overcoming the above disadvantages in providing a simply constructed mat cutting apparatus which is designed to accomplish the entire mat cutting operation from sizing of the mat to be used through the completion of the bevel cut of the opening therein.
The present invention utilizes a guide rail which is constructed from angle iron material having one side or leaf thereof extending upwardly to serve as a guide rail for the cutting mechanism. The other leaf of the angle iron guide rail rests directly on the matting material to be cut which serves to help hold the material in place and also provides an outer edge to use as a simple straight edge in the initial cutting of the material to size. The guide rail is pivotally mounted by a pair of elongated L-shaped bars to the outside edges of the cutting board. The mounting permits the outside edges of the cutting board to be provided with upwardly extending sidewalls which are parallel with respect to each other and perpendicular to the elongated guide bar thereby providing a squaring means for the material to be held in place thereby.
A movable fence apparatus is securable in place between the sidewalls in order to provide a stop for the edge for the material when it is placed in the bevel cutting position. The cutting mechanism itself consists of a group of plates sandwiched together in order to securely hold in place a standard off-the-shelf type single edge razor blade and simultaneously provide a groove for slidably receiving the upper edge of the angle iron guide rail therein.
An auxiliary measuring device is included which greatly simplifies the setting of the stop fence and the length cut of the blade itself. This auxiliary measuring device generally comprises an elongated scale member having a sliding block thereon and a stop member at one end. The scale member is provided with graduations from each end ascending toward the middle of the scale. The sliding block when fully moved to the stop member end of the scale provides a zero edge while the opposite end of the scale provides a second zero edge so that measurements of the matting material can be made from both edges thereof. The sliding block then serves as a handy device for checking the square alignment of the stop fence of the apparatus.
No scribing is necessary in predetermining the mat width or operation of the cutting tool. This, in eliminating previously required steps, also precludes the human error usually present in the scribing operation.
The cutting board itself, in order to facilitate holding the mat material in place is provided with a roughened or tacky surface directly beneath the guide rail means.
This machine can be produced inexpensively and it can easily be purchased by the "artist" himself for his own mat-cutting requirements. It can be maintained in the artist's studio thereby giving him ready access to his mat requirements and at a fraction of the cost of having mats custom cut in frame shops.
DESCRIPTION OF THE DRAWINGS
Other and further advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:
FIG. 1 is a prospective view of a mat cutting apparatus embodying the present invention.
FIG. 2 is a plan view of the mat cutting apparatus of FIG. 1.
FIG. 3 is a side elevational sectional view taken along the broken lines 3--3 of FIG. 2.
FIG. 4 is a detailed view of the cutting apparatus taken along the broken lines 4--4 of FIG. 3.
FIG. 5 is a detail of one end of the guide rail mechanism taken along the broken lines 5--5 of FIG. 2.
FIG. 6 is a plan view of an auxiliary scaling apparatus used in conjunction with the mat cutting apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, reference character 10 generally indicates a mat cutting apparatus for preparing matting material indicated by reference character 12 for picture framing and the like. The apparatus 10 generally comprises a baseboard apparatus 14 having guiderail means 16 pivotally attached thereto and having a movable cutting apparatus 18 for operation therewith. The apparatus 10 also comprises a fence stop means 20 and an auxiliary measuring device 22.
The baseboard apparatus 14 comprises a rectangular board 24 having a front edge 26, a rear edge 28 and opposite side edges 30 and 32. The side edges 30 and 32 are provided with upwardly extending sidewalls 34 and 36, respectively which are constructed to be parallel with respect to each other. The sidewalls 34 and 36 are further constructed from angle-iron material with the one leaf thereof extending under the baseboard 24 which provides some support therefore. The outside surface of each sidewall 34 and 36 is provided with a flat plate member 38 and 40 respectively which is adjustably attached thereto by means of screws 42 and oversize bores 44.
The upper surface of the board 24 is provided with an elongated vertical groove 46 which extends between the sidewalls 34 and 36 and is perpendicular thereto. The groove 46 is spaced a preselected distance from the rear edge 28 of the board 24. The upper surface of the board 24 is provided with an angled groove 48 which extends downwardly and away from groove 46 and is spaced therefrom. The angled groove 48 also extends between the sidewalls 34 and 36 and is perpendicular thereto. A strip of anti-skid material 50 is provided on the top surface of the baseboard 24 between the sidewalls 34 and 36 and is disposed between the grooves 46 and 48 for a purpose that will be hereinafter set forth.
The upper surface of the board is also provided with an elongated scale member 52 which is disposed along the inside edge of the sidewall 36 within a recess 54. The scale 52 is longitudinally adjustable within the recess 54 by means of a slot 56 at one end thereof and adjustment screw 58.
In ordinary operation of the apparatus, the scale is adjusted so that the 0 indicia is in direct alignment with the angled groove 48, again for a purpose that will be hereinafter set forth.
The guide rail means generally depicted by reference character 16 comprises an elongated angle iron bar 60 made up of two leaf members 62 and 64 which are joined along one edge to form a substantially V-shaped cross-section which is best shown in FIG. 3. The bar 60 however is constructed from a single piece and folded to create the leaf members 62 and 64 as opposed to actually joining them together by welding or other means. Each end of the leaf member 64 is provided with an L-shaped attachment bar 66 and 68, one leg of each said bar being pivotally connected to the baseboard side plates 38 and 40, respectively, by means of oppositely disposed pivot pins 70 and 72 respectively.
The pivot arms 66 and 68 are disposed so as to support the elongated bar 60 in position between the grooves 46 and 48 in the baseboard 24. The leaf member 62 of the guide rail 60 has an outer edge depicted as 74 and is disposed to be directly above the groove 46 when the guide rail 60 is pivoted into contact with the upper surface of the baseboard 24 as shown in FIG. 3. At the same time when the guide rail 60 is in substantial contact with the upper surface of the baseboard 24, the plane of the leaf member 64 is in substantial alignment or parallel with the angled groove 48 and slightly rearward thereof. The portion of the leaf member 62 contacting the upper surface of the baseboard 4 contacts it at or directly above the roughened strip portion 50. The rear edge 74 of the leaf 62 is raised slightly off the upper surface of the board.
The view shown in FIG. 4 depicts a piece of matting material 12 located on the upper surface of the board 24 and having the leaf member 62 resting thereon. In order to place the mat 12 in the shown position, the entire guide rail 60 is pivoted upwardly by means of the attachment arms 66 and 68 while a mat 12 is put into place.
The blade holding apparatus 18 comprises a pair of flat plate members 76 and 78 which are attached together by means of a bolt and nut 80 and spaced apart by a slide block 82 sandwiched therebetween. The slide block 82 is smaller than the plate members 76 and 78 thereby forming a groove 84 between the said blocks or plate members 76 and 78. The size of the slide block 82 is determined by the thickness of the leaf 64 of the guide rail so that the upper edge of outer edge thereof is slidably received within the groove 84. It is noted that the slide block 82 is best constructed from a teflon or phenolic block material which is easily slidable on the edge of the leaf member 64 of the guide rail 60.
The outer surface 86 of the plate member 78 is disposed to lie directly in the plane of the angle groove 48 when the guide rail 60 is in its downward position as shown in FIG. 3. A third plate member 88 is secured to the outer surface 86 of the plate member 78 by means of a pair of bolt and wing nuts 90 and 92. The plate members 78 and 88 are provided with a pair of aligned grooves thereby forming a slot 94 which is disposed at an angle of approximately 45° and sized to receive the backbone or ridge plate 96 of an ordinary standard single edge razor blade 98. The lower edge 100 of the plate 88 is cut off in order to allow the lower corner and cutting edge 102 of the blade 98 to extend therebelow. It is best to orient the plate member 88 at an angle corresponding to that of the razor blade 98 so that the opposite and unused corner of the blade 98 is covered by the plate 88 for safety purposes.
The lower cutting edge or corner 102 of blade 98 extends downwardly into the groove 48 when the guide rail 60 is pivoted downwardly in contact with the upper surface of the board 24 or the mat 12 placed thereon as the case may be.
The stop fence 20 generally comprises an elongated flat bar 104 which extends between the sidewalls 34 and 36 and is substantially perpendicular thereto. The bar 104 is not attached to the baseboard but is slidably movable thereon. Each end of bar 104 is provided with plate members 106 and 108 each having an upwardly extending guide wall 110 and 112 respectively on the outer edge thereof. The guide walls 110 and 112 are disposed to be in sliding engagement with the inside surface of the sidewalls 34 and 36 of the baseboard 24. The sidewalls serve to substantially maintain the bar 104 in an orientation perpendicular to the said sidewalls 34 and 36. The plate members 106 and 108 are disposed rearwardly of the leading edge of the bar designated at 114. The leading edge 114 of the fence is alignable with the scale 52.
The auxiliary scale member 22 comprises an elongated scale rod 116 which is provided with a scale indicia 118 on the upper surface thereof. The indicia 118 graduates from 0 to 4 from one end of the scale and descending back to a second 0 near the opposite end thereof. The opposite end of the rod 116 is provided with a transverse T-stop member 120. A sliding block member 122 is slidably secured to the rod 116 and movable from one end to the other thereof. The length of the block member 122 is such that when the block member 122 is disposed against the stop member 120 the forward edge 124 thereof is in alignment with the second 0 indicia.
The steps utilizing the apparatus 10 are as follows: The overall sizing of the matting material may be accomplished by simply inserting the matting material under the guide rail 60 and cutting the outside edge thereof using an ordinary knife blade, razor blade or the like along the rear edge 74 of the leaf member 62 allowing the tip of the blade (not shown) to enter the groove 46 of the baseboard. While making these cuts it is obvious that the inside surfaces of either of the sidewalls 34 and 36 may be used as a squaring edge for the material 12.
After the board has been cut to its overall desired dimensions, the width of the finished mat is determined. For example, referring now to FIG. 2, the fence stop member 104 is adjusted so that the forward edge 114 is in alignment with indicia 3 1/2 on the scale 52. The measuring apparatus 22 is then placed in the position as shown at reference character 1 in FIG. 2. The sliding block 122 is then held in place with respect to the scale member 116 and the apparatus 22 is then moved the opposite end of the board at the position shown at reference character 2. The fence member 104 is then adjusted so that it is perfectly square or parallel with the rear edge 28 of the baseboard 24. This aligns the leading edge 114 of the stop fence member 104 perpendicular with respect to the sidewalls 34 and 36 and at the position 3 1/2 of the scale 52. The leading edge 114 of the fence member 104 is now 31/2 units from the angled groove 48.
The fence member 104 is then locked into place by means of a pair of hand operated clamps or the like 126 and 128. The clamps 126 may be ordinary paper clip type clamping means which is placed over the upper edge of the guide wall 110 and the baseboard sidewall 34. Likewise, the clamp 128 is placed over both the fence guide wall 112 and the baseboard sidewall 36.
The matting material is then placed under the guide rail 60 with one edge thereof against the leading edge 114 of the stop fence and the right angled edge thereof being against the inside surface of the sidewall 36. The auxiliary measuring tool 22 is then placed in position 3 as shown in FIG. 2 with the sliding block member moved all the way back against the stop member 120. The blade holding mechanism 18 is placed on the leaf member 64 of the guide rail 60 so that the cutting blade corner 102 is directly in line with the indicia mark 31/2 of the auxiliary measuring tool 22.
The next step is to move the auxiliary measuring tool 22 to the opposite side of the mat member at position 4 butting the forward end 119 directly against the inside surface of the sidewall 36 and placing the sliding block 122 at a position so one edge thereof is adjacent to the opposite 31/2 position on the scale.
The cutting holder means 18 is then pressed downwardly thereby inserting the corner of the blade through the matting material as clearly shown in FIG. 4. The blade is then slidably moved toward the sidewall 36 until the cut is completed opposite the 31/2 marking on the auxiliary scale member. The mat material is then rotated 180° so that the first bevel cut indicated by reference character 130 is forward of the cutting board as shown in FIG. 1. The auxiliary measuring apparatus 22 is then moved back to position 3 shown in FIG. 2 and steps 3 and 4 are repeated thereby cutting the opposite bevel cut shown by the dashed lines 132 in FIG. 1.
The matting material is then rotated 90° and a cut is made between the end of the cuts 130 and 132 and finally the mat material is rotated 180° to complete the bevel cut. The center portion of the mat that has been cut free is removed thereby leaving a finished picture mat.
From the foregoing, it is apparent that the invention provides a mat cutting apparatus which is particularly designed and constructed to permit the accurate cutting of the bevel mat for picture framing and the like which is accurate and professional without the use of a complicated and expensive machine.
Whereas, the present invention has been described in relation to the drawings attached hereto, other and further modifications apart from those shown or suggested herein may be made within the spirit and scope of the invention. | A mat bevel cutting method and apparatus having a pivotal mounted cutting guide rail in conjunction with sidewalls which serve to hold the matting material in place and squared during the cutting operation. The apparatus also includes built-in auxiliary measuring and alignment tools to facilitate accurate alignment and cutting. | 8 |
FIELD
A combined belt and necktie rack, which provides an efficient structure for hanging and storing both belts and neckties simultaneously, is disclosed.
BACKGROUND
Many individuals possess numerous neckties and belts. This large quantity of neckties and belts may offer the individual a variety of styles and choices for different occasions and settings. An issue that often arises when possessing a large number of neckties and belts is related to storage and organization. In particular, for various reasons, belts and neckties are not suitable for being folded, rolled, or otherwise compacted for storage in a drawer. Further, storage in a drawer may not allow an individual to quickly and easily view each belt and necktie when deciding which combination will be worn.
To address this issue regarding the difficulty of storing belts and neckties in drawers, many individuals choose to hang their belts and neckties. For example, some individuals may choose to hang belts and/or neckties on clothes hangers or on pegs on the back of a closet door. Although hanging belts and neckties in this fashion may somewhat reduce the likelihood that these items will be damaged during storage, this practice is inefficient. In particular, only a small number of belts and neckties may be stored on each hanger and on each general purpose peg. Further, since these structures are not intended to hold belts and neckties, belts and neckties may be precariously held on these devices and may be prone to fall/slide off.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
SUMMARY
Most men need a belt rack and men who wear suits and neckties need a necktie rack. With the appropriate design, the two functions may be combined in the same rack. In building a necktie rack, the pegs of the rack may be positioned closely together (e.g., ½-inch apart) because the neckties are hung flat against each other. In building a belt rack in which the belts are hung on the pegs by their buckles, however, the belts are not hung flat against each other but are turned perpendicular from the neckties and hung width-by-width. Thus, the pegs must be positioned at least 1½-inches apart to accommodate the widths of belt buckles. So it is problematic to construct a combination belt-and-necktie rack that is efficient at hanging both belts and neckties, so long as the belts are hung by their buckles. Furthermore, this peg-through-buckle system will never accommodate all belts, in any case, because approximately 15% or more of belts on the market have a solid metal-plate buckle (i.e., no hole in the buckle).
To overcome the above problems, the combined belt and necktie rack described herein hangs belts via pegs through the normal holes in their leather strap rather than by the buckles. If the pegs are made from small-diameter, rigid stainless steel, the belts can effortlessly be slid onto the pegs through one of the holes in the strap. The steel easily supports the belts' weight, and if the pegs are long enough, they will accommodate neckties being draped over the pegs as well. In some embodiments, the end of each peg (e.g., the last ⅜-inch of the peg) may be bent horizontally at a right angle to the rest of the peg, for the belt to be hung. That way, the belts and the neckties are parallel to each other and lay flat against each other, rather than a space-consuming perpendicular arrangement.
It is contemplated that the frame piece, into which the pegs are mounted, be a light metal, such as aluminum. This results in a modern styling. However, if a more traditional appearance is desired, the frame piece may be made out of oak or some other hardwood. It is further contemplated that the steel pegs may project from both sides of the frame piece, thereby doubling the capacity of the rack. In this case, the rack would be mounted to the wall at one end of the frame piece with a swivel/pivot hinge bracket, allowing the rack to lay flat against the wall when not in use, but be swung out to access both sides during selection of a necktie or a belt. A one-sided version of the rack may also be made where the rack is mounted stationary against the wall with screws. In yet another embodiment, the rack may be installed on a track mounted inside a cabinet or closet, which allows the rack to slide in for storage but out for selection of a belt and/or a necktie.
In one embodiment, the pegs extend 1¼-inches from the frame piece to accommodate necktie widths and are spaced 1¼-inches apart to accommodate male fingers accessing a belt. In some embodiments, an upper and lower row of pegs may be installed 1-inch apart vertically with the pegs staggered in a saw-tooth pattern to double the capacity of the rack. Furthermore, the front section of the pegs (i.e., the last ⅜-inch section at the end of the pegs that is 90 degrees from the rest of the peg) may include a number of features, including 1) a slight upward slant or curve to prevent a belt hanging by its hole from accidentally sliding off; (2) a 90° corner between this front section and the rest of the peg may be sharp (i.e., not a gradual curve) to inhibit a hanging belt from sliding around the corner; and (3) the 90° corner may have a spherical knob to further prevent a hanging belt from sliding around the corner.
The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment of the invention in this disclosure are not necessarily to the same embodiment, and they mean at least one.
FIG. 1A shows a perspective view of a combined belt and necktie rack according to one embodiment.
FIG. 1B shows an exploded view of a combined belt and necktie rack according to another embodiment.
FIG. 2 shows a side view of a combined belt and necktie rack according to one embodiment.
FIG. 3 shows an example peg according to one embodiment.
FIG. 4 shows a necktie held on the middle section of a peg according to one embodiment.
FIG. 5 shows a spherical knob placed at the bend between a front section and a middle section of a peg according to one embodiment.
FIG. 6 shows a belt and a tie hanging parallel to each other on a front section and a middle section of a peg, respectively, according to one embodiment.
FIG. 7 shows a mounting block including a support plate and a pivot arm according to one embodiment.
DETAILED DESCRIPTION
Several embodiments are described with reference to the appended drawings are now explained. While numerous details are set forth, it is understood that some embodiments of the invention may be practiced without these details. In other instances, well-known circuits, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.
FIG. 1A shows a combined belt and necktie rack 100 according to one embodiment. The combined belt and necktie rack 100 may include a set of pegs 101 , a frame piece 103 , and one or more mounting blocks 105 . As will be described in greater detail below, the combined belt and necktie rack 100 allows for the efficient storage/hanging of a number of belts and neckties. In particular, the combined belt and necktie rack 100 allows for belts and neckties to be easily placed on the rack 100 , viewed on the rack 100 , and removed from the rack 100 . Each of the elements of the combined belt and necktie rack 100 will be now described by way of example.
The frame piece 103 may be a rigid structure that is equipped to receive the set of pegs 101 . In one embodiment, as shown in FIG. 1A , the frame piece 103 may be defined by a thin, elongated rectangular structure. Although shown as rectangular, in other embodiments the frame piece 103 may be formed in other shapes, including a cylinder or a prism.
The frame piece 103 may be formed of various materials, including plastic polymers (e.g., polystyrene and polyvinyl chloride), woods (e.g., oak, pine, mahogany, walnut, and teak), elemental metals (e.g., aluminum), metal alloys (e.g., steel), or some combination of these materials. In some embodiments, the frame piece 103 may be a solid structure (i.e., without hollow sections). This solid construction may be appropriate for lighter materials (e.g., woods) that provide a stable structure while still offering a manageable weight such that the rack 100 may be easily mounted. In other embodiments, the frame piece 103 may be at least partially hollow. For example, the frame piece 103 may be made of a hollow aluminum casing that provides a high specific strength (i.e., strength-to-weight ratio). The casing that defines this hollow, aluminum frame piece 103 may have a wall thickness between 1/16-⅛ inches. Accordingly, in this embodiment, the frame piece 103 may be made of denser materials, but may still maintain a manageable weight for mounting.
The frame piece 103 may be formed with various dimensions according to the requirements/needs of the user. For example, the frame piece 103 may be between 12.0-48.0 inches in length, between 2.0-3.0 inches in width, and between 0.5-3.0 inches in depth. The dimensions of the frame piece 103 may be based on 1) the number of pegs 101 desired by the user, which in turn may correspond to the number of belts and/or neckties owned by the user and/or 2) the space/structure in which the combined belt and necktie rack 100 will be installed. For example, the combined belt and necktie rack 100 may be installed in a closet having a width of 36.0 inches. In this situation, the frame piece 103 may be 36.0 inches in length. In other embodiments, the frame piece 103 may be slightly smaller than the provided installation space to accommodate for the one or more mounting blocks 105 , which may be needed for installation, as will be described in greater detail below.
In one embodiment, the pegs 101 may be thin cylindrical structures that are coupled or otherwise attached along the length of the frame piece 103 . Accordingly, in some embodiments, the pegs 101 may have a circular cross-sectional shape; however, in other embodiments, the pegs 101 may have a different cross-sectional shape (e.g., triangular or rectangular). The pegs 101 may be formed of various materials, including plastic polymers (e.g., polystyrene and polyvinyl chloride), woods (e.g., oak, pine, mahogany, walnut, and teak), elemental metals (e.g., aluminum), metal alloys (e.g., steel), or some combination of these materials. In some embodiments, the pegs 101 and the frame piece 103 are formed of different materials, while in other embodiments the pegs 101 and frame piece 103 are formed from the same material.
In one embodiment in which both the pegs 101 and the frame piece 103 are formed from metals, the pegs 101 may be soldered or welded to the frame piece 103 as shown in FIG. 1A . In other embodiments, different types and/or mechanisms may be used for coupling the pegs 101 to the frame piece 103 . For example, as shown in FIG. 1B , in one embodiment, vertical holes 107 may be drilled into the top of the frame piece 103 . The vertical holes 107 may have a diameter slightly larger than the cross-sectional diameter of the pegs 101 such that a peg 101 may fit within each of the vertical holes 107 securely preventing the pegs 101 from rotating forward under the weight of a belt. In one embodiment, channels 109 may be included on the top side of the frame piece 103 and aligned with the vertical holes 107 . The length of the channels 109 may extend across the width of the frame piece 103 and the width of the channels 109 may be sized to accommodate the cross-sectional diameter of the pegs 101 . Accordingly, the pegs 101 may be inserted into the vertical holes 107 and through engagement with the channels 109 the pegs 101 are held static relative to frame piece 103 .
In some embodiments, a locking bar 111 may secure the pegs 101 within the channels 109 and/or the vertical holes 107 . The locking bar 111 may have a length and width equal to that of the top part of the frame piece 103 such that the locking bar 111 may cover the channels 109 and the vertical holes 107 . In some embodiments, the locking bar 111 may form hemi-cylindrical grooves 115 , which along with complimentary channels 109 , securely hold the pegs 101 . The grooves 115 may be equal in size to the channels 109 such that a combined set of groove 115 and channel 109 is shaped to completely fit around the circumference of the a cross-section of a peg 101 . As shown in FIG. 1B , the locking bar 111 may be coupled to the frame piece 101 using screws 113 . However, in other embodiments, any mechanism may be used for coupling the locking bar 111 to the frame piece 103 .
Although FIG. 1A and FIG. 1B show two embodiments for coupling the pegs 101 to the frame piece 103 , the pegs 101 may be coupled to the frame piece 103 using any mechanism. For example, the pegs 101 may be coupled to the frame piece 103 using screws, bolts, clips, clamps, or other removable fasteners. In these example embodiments or in the example shown in FIG. 1B , the pegs 101 may be adjustable by a user. For example, the pegs 101 may be moved, removed, and/or added to the frame piece 103 as desired by the user by coupling and decoupling the pegs 101 from the frame piece 103 using these removable fasteners.
In one embodiment, the pegs 101 may be coupled to frame piece 103 during manufacture. In this embodiment, the pegs 101 may be spaced to accommodate the width of a standard belt, the width of a standard necktie, and/or to allow the fingers of an average sized human user to easily grab/select a necktie or belt. For instance, as shown in FIG. 2 , the pegs 101 may be separated by the distance D. In one embodiment, the distance D may be 1¼ inches. Using this separation distance D, the fingers of a user may easily grab a necktie or belt without interfering with other neckties and belts held by adjacent pegs 101 . In other embodiments, the distance D between each peg 101 along the frame piece 103 may be between 0.75 inches and 1.5 inches. In these examples, the measurements for D are taken from the leftmost boundary of a first peg 101 to the right most boundary of an adjacent second peg 101 as shown in FIG. 2 .
FIG. 3 shows an example peg 101 according to one embodiment. The example peg 101 shown in FIG. 3 may each include three sections: a base section 201 , a middle section 203 , and a front section 205 . Each of the sections 201 , 203 , and 205 may be separated by one or more bends 209 A and 209 B that are defined by the angles θ and α, respectively. Accordingly, the base section 201 is separated from the middle section 203 by the bend 209 A defined by the angle θ while the middle section 203 may be separated from front section 205 by the bend 209 B defined by the angle α. Each of these sections 201 , 203 , and 205 and corresponding bends 209 A and 209 B will be described in further detail below.
The base section 201 may be used for coupling the peg 101 to the frame piece 103 and may be approximately ⅜ to ½ inches in length. In some embodiments, the pegs 101 may be coupled directly to the frame piece 103 using one or more fasteners (e.g., screws and bolts). For example, the base section 201 may be a straight structure that may be directly soldered, welded, or otherwise fastened to a front face 207 A of the frame piece 103 . In other embodiments, the pegs 101 may be indirectly coupled to the frame piece 103 . For example, as shown in FIG. 2 , a first set of pegs 101 may be coupled to an intermediate frame 211 . In particular, the base section 201 of each peg 101 in the first set of pegs 101 may be coupled to the intermediate frame 211 using one or more fasteners, including bolts, screws, clips, clamps, solder, etc. Thereafter, the intermediate frame 211 may be coupled directly to the frame piece 103 using any type of fasteners, including bolts, screws, clips, clamps, solder, etc. As shown, the intermediate frame 211 is coupled to the frame piece 103 using tabs 213 , which are part of the intermediate frame 211 , and screws 215 . However, as noted above, any type of fasteners may be used. Using the intermediate frame 211 allows multiple pegs 101 to be simultaneously coupled to the frame piece 103 during manufacture or installation. Although the first set of pegs 101 are coupled indirectly to the frame piece 103 via the intermediate frame 211 , as noted above in other embodiments, the pegs 101 may be directly coupled to the frame piece 103 . For example, as shown in FIG. 2 , a second set of pegs 101 , which are below the first set of pegs 101 , may be coupled directly to the frame piece 103 .
As noted above, other techniques may be used for coupling the pegs 101 to the frame piece. For example, as shown in FIG. 1B and described above, the pegs 101 may be coupled to the frame piece 103 using the vertical holes 107 , the channels 109 , and/or the locking bar 111 .
As described above, the base section 201 may be used to couple pegs 101 to the frame piece 103 (either directly or indirectly). In contrast, the middle section 203 may be used to hold a necktie as will be described in greater detail below. In one embodiment, as noted above, the middle section 203 may be separated from the base section 201 by the bend 209 A, which has an angle θ. In some embodiments, the middle section 203 is perpendicular to the base section 201 . Accordingly, in these embodiments, θ may be equal to 90°. In other embodiments, the middle section 203 may form an upward slope in relation to the base section 201 . This upward slope assists in preventing neckties held by the middle section 203 from sliding forward toward the front section 205 and consequently falling off the combined belt and necktie rack 100 . In this embodiment, θ may be between 91° and 130° such that an upward slope is created between the base section 201 and the middle section 203 . The bend 209 A defined by the angle θ may be a sharp bend as shown in FIGS. 1B and 3 , which forms a point and an abrupt transition between the base section 201 and the middle section 203 . In other embodiments, the bend 209 A defined by the angle θ may be a gradual bend, which forms a rounded curve as shown in FIGS. 1A and 2 .
FIG. 4 shows a necktie 401 held on the middle section 203 . In this embodiment, the necktie 401 is folded in half or nearly in half and draped over middle section 203 . By being draped over the middle section 203 , the necktie 401 may be sturdily held by the peg 101 . In one embodiment, the middle section 203 may have a length to accommodate the dimensions of an average or standard necktie. Since neckties are folded over middle section 203 , the width of the average/standard necktie may be measured at the midpoint of neckties. For example, the length of the middle section 203 may be between ⅜ of an inch and 1.5 inches. In particular, the length of the middle section 203 may be 1.25 inches.
In one embodiment, the front section 205 may be used to hold a belt as will be described in greater detail below. As noted above, the front section 205 may be separated from the middle section 203 by the bend 209 B, which has an angle α. In some embodiments, the front section 205 is perpendicular to the middle section 203 . Accordingly, in these embodiments, α may be equal to 90°. In some embodiments, the angle α may be sharp (i.e., forming a distinct point between the middle section 203 and the front section 205 ) as shown in FIGS. 1B and 3 . This sharp angle may inhibit a belt held on the front section 205 from sliding around the bend and onto the middle section 203 . As shown in FIG. 5 , in some embodiments, a spherical knob 501 may be placed at the bend 209 B between the front section 205 and the middle section 203 . The spherical knob 501 may have a diameter greater than the diameter or cross-sectional width of the middle section 203 and/or the front section 205 . As will be described in greater detail below, the knob 501 may further prevent a hanging belt from sliding onto the middle section 203 .
In one embodiment, the cross-sectional size and shape of the base section 201 , the middle section 203 , and the front section 205 may be identical. For example, each of the sections 201 , 203 , and 205 may be cylindrical structures (i.e., a circular cross-section) and between 2.0 millimeters and 4.5 millimeters in diameter. In this embodiment, the pegs 101 are sized to fit through the holes in a strap of a standard belt (i.e., a hole punched in the leather strap of a belt and designed to receive a prong of a corresponding buckle). In particular, a user may pass the front section 205 of a peg 101 through a hole 505 of a belt 503 as shown in FIG. 5 . In one embodiment, the hole 505 farthest from the buckle 507 of the belt 503 may be chosen to pass through the front section 205 of the peg 101 and the belt 503 may be hung with the buckle 507 of the belt 503 hanging downward in relation to the peg 101 . In one embodiment, the belt 503 may remain on the front section 205 . In this embodiment, the knob 501 may be located at the bend 209 B between the front section 205 and the middle section 203 as shown in FIG. 5 to prevent the belt 503 from sliding onto the middle section 203 where a necktie may be hanging. Accordingly, as noted above, the knob 501 may be sized to be greater in diameter than the hole 505 of the belt 503 (e.g., the diameter of the knob 501 may be greater than 4.5 millimeters). Although described as spherical, in other embodiments, the knob 501 may be any shape, including rectangular and conical.
In embodiments in which the front section 205 forms a 90° angle with the middle section 203 , a belt 503 and necktie 401 hanging on a front section 205 and a middle section 203 of a peg 101 , respectively, may be parallel to each other as shown in FIG. 6 . This parallel arrangement of the belt 503 and the neckties 401 provides a more space efficient system in comparison to a perpendicular belt and necktie arrangement.
Although described as the middle section 203 holding neckties and the front section 205 holding belts, in some embodiments after passing through the front section 205 , a belt may be pushed along the continuous peg 101 structure to the middle section 203 . In these embodiments, which do not include the knobs 501 , the belt may be pushed to rest against the base section 201 and/or the frame piece 103 . In particular, although the belt remains on the middle section 203 , the belt may be moved to be proximate to the base section 201 and/or the frame piece 103 . By moving the belt to rest against the base section 201 and/or the frame piece 103 , the belt may maintain some contact and support from the base section 201 and/or the frame piece 103 . Further, by moving the belt to rest against the base section 201 and/or the frame piece 103 , enough room may remain along the middle section 203 to accommodate a necktie.
Although described above as the cross-sectional size and shape of base section 201 , the middle section 203 , and the front section 205 being identical, in some embodiments, the sections 201 , 203 , and 205 may have differently shaped and/or sized cross-sections. For example, as previously described, the middle section 203 and/or the front section 205 may be sized to fit through a hole in a standard sized belt. In contrast, the base section 201 may not need to be sized to be similar to the middle section 203 and the front section 205 since the base section 201 is not designed to fit through a hole in the strap of a belt. In particular, the base section 201 may be a wider and/or flatter structure in comparison to the narrow, cylindrical shape of the middle section 203 and/or the front section 205 . This wider and/or flatter structure may assist in providing a larger surface area for coupling the base section 201 to the frame piece 103 .
In some embodiments, the front section 205 may be angled or curved upward relative to the highest point of the middle section 203 . For example, the front section 205 may form a slope or curve upwards at an angle β relative to a horizontal plane at the highest vertical point of the middle section 203 as shown in FIG. 3 . The slope upwards may inhibit a necktie from slipping off the peg 101 . In one embodiment, the angle β may be between 5° and 10°. For example, the angle β may be 7°
In one embodiment, the combined belt and necktie rack 100 may be coupled to a wall or another structural element using the one or more mounting blocks 105 . In one embodiment, a mounting block 105 may be placed on either end of the frame piece 103 for fixing the combined belt and necktie rack 100 to a structure.
In other embodiments, a single mount block 105 may be used for pivotally coupling the combined belt and necktie rack 100 to a wall or structure. For example, a mounting block 105 may include a support plate 701 and a pivot arm 703 as shown in FIG. 7 . The support plate 701 may be a flat structure that is used for attaching the combined belt and necktie rack 100 to a wall or another structure. For instance, the support plate 701 may include a set of holes for receiving a corresponding set of bolts or screws, which may be sunk into a wall. In other embodiments, the support plate 701 may be attached to a wall or another structure using other attachment mechanisms (e.g., clips, clamps, adhesives, etc.). The pivot arm 703 may be a structure that couples the mounting block 105 to the frame piece 103 while allowing the frame piece 103 to pivot in relation to the mounting block 105 and/or in relation to a structure on which the combined belt and necktie rack 100 has been installed (e.g., a wall). In one embodiment, the pivot arm 703 and the support plate 701 may be one continuous piece, while in other embodiments the pivot arm 703 and the support plate 701 may be separate pieces. In embodiments in which the pivot arm 703 and the support plate 701 are separate pieces, the support plate 701 and the pivot arm 703 may be coupled together using any coupling mechanism (e.g., screws, bolts, clips, clamps, adhesives, solder, etc.).
In one embodiment, the pivot arm 703 may include a joint element 705 A, which works in conjunction with a joint element 705 B of the frame piece 103 and a pin 707 , for allowing the frame piece 103 to pivot in relation to the mounting block 105 . As shown, the joint elements 705 A and 705 B along with the pin 707 form a barrel hinge; however, in other embodiments, the combined belt and necktie rack 100 may include another type of joint, including a pivot hinge. By providing a pivoting connection, the mounting block 105 (in particular the pivot arm 703 ) allows the combined belt and necktie rack 100 to be stored away or adjusted for easier access. For example, in one embodiment, the rack 100 may rest against a wall of a closet; however, the rack 100 may be pivoted outwards into an opening of the closet to provide improved access for the user. Upon selecting a belt and/or necktie, the rack 100 may be pivoted back against the wall of the closet. Accordingly, by providing a pivoting connection, the rack 100 may be easily stored away while still allowing for easy access to belts and neckties.
Although described with a pivoting structure, in other embodiments, the mounting blocks 105 may provide a sliding track structure. In these embodiments, the mounting blocks 105 allow the frame piece 103 to be coupled to a wall of a cabinet or closet and slid parallel to the wall to provide access to belts and neckties held on the rack 100 . In particular, the frame 103 may be slid into a closet for storage and out of a closet for selection of belts and neckties by a user.
In one embodiment, the combined belt and necktie rack 100 may include multiple rows of pegs 101 . For example, as shown in FIG. 1A and FIG. 2 , in one embodiment, the rows of pegs 101 may be vertically separated by between 0.75 inches and 1.5 inches. For example, rows of pegs 101 may be separated by 1.0 inches. This measurement may be calculated from identical elements of pegs 101 on each row of pegs 101 . FIG. 2 shows multiple rows of pegs 101 on both a front face 207 A and a rear face 207 B of the frame piece 103 . In this embodiment, the belts and neckties on each face 207 A and 207 B may be accessed by pivoting the frame piece 103 via the mounting block 105 as described above. Further, each row of pegs 101 on each face 207 A and 207 B may be offset (i.e., each peg 101 on one row may be located between two pegs 101 on a vertically adjacent row). By being offset from each other, each peg 101 may accommodate belts and/or neckties without interfering with belts and neckties hanging on pegs 101 on a vertically adjacent row.
Although each of the pegs 101 on the rack 100 has been described jointly, in some embodiments, each peg 101 may be variably sized and arranged to accommodate for the various types, styles, and sizes of belts and neckties. The decision of the sizes and arrangement of pegs 101 may be made by users or by a manufacturer based on market data.
As described above, a combined belt and necktie rack 100 is described that provides an improved system for hanging and storing belts and neckties. In particular, by hanging belts on pegs 101 through holes in the straps of these belts, the rack 100 may efficiently accommodate a number of belts. Further, by providing elongated pegs 101 , the rack 100 may simultaneously hold neckties along with belts in a fashion that allows for efficient storage and easy viewing and removal of belts and neckties. Accordingly, the combined belt and necktie rack 100 described herein provides a more efficient and improved system for hanging and storing belts and neckties by allowing belts and neckties to be hung parallel to each other.
While certain embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that the invention is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. The description is thus to be regarded as illustrative instead of limiting. | A combined belt and necktie rack described herein hangs belts via pegs through holes in their leather straps rather than by the buckles. If the pegs are made from small-diameter, rigid materials the belts can effortlessly be slid onto the pegs through a hole in the strap. The pegs easily support the belts' weight, and if the pegs are long enough, they will accommodate neckties being draped over the pegs as well. The end of each peg may be bent horizontally at a right angle to the rest of the peg, for the belt to be hung. In this fashion, belts and neckties are parallel to each other and lay flat against each other, rather than a space-consuming perpendicular arrangement. The pegs may be coupled to a frame piece which may thereafter use mounting blocks to either statically or dynamically couple the frame piece and corresponding pegs to a structure. | 0 |
The invention relates to a method and apparatus for controlling a crimping process serving for the connection of a contact with a conductor, wherein a crimping tool of a crimping press is movable from a starting position into a crimping position and subsequently into an end position.
BACKGROUND OF THE INVENTION
Equipment for producing a crimped connection has become known from U.S. Pat. No. 5,966,806. A motor drives an eccentric shaft which moves a carriage with crimping tools up and down. An encoder driven by means of the motor shaft serves for positional determination of the crimping tool. The crimp contact to be connected with a conductor end lies on a stationary anvil, wherein lugs of the crimp contact are plastically deformed on downward movement of the crimping tool and produce the connection to the conductor. The position of the crimping tool in the crimping region is measured by means of a height sensor, wherein the sensor signal is used independently of the encoder signal. At the same time the crimping force is measured on the basis of the motor current. The measurement values are compared with reference values. The comparison enables a statement about the crimp quality.
Although an encoder and a height sensor are present, only a relatively imprecise statement about the crimp quality can be made, because external influences as well as the degree of elasticity or rigidity of the mechanical driven elements are not taken into consideration.
The present invention avoids the disadvantages of the known equipment and is accordingly directed to a method and apparatus in which the crimp quality of a crimped connection can be improved.
BRIEF DESCRIPTION OF THE INVENTION
The advantages achieved by the invention are essentially to be seen in that alteration of the crimping press is not necessary for processing different crimp contacts by different tool strokes. The crimping height and the crimping stroke are adjustable. Moreover, the crimping press control recognizes the exact tool position each time the press is activated, whereby a simple evaluation of the crimping force versus crimping stroke can be made and other machines participating in the crimping process can be synchronized.
The crimping press according to the invention operates with two measuring systems, by means of which a regulation of the drive with respect to position or crimping height regulation can be obtained. A rotative measuring system is coupled with a linear measuring system. The rotative measuring system enables a high positioning dynamic, because no dead times, caused by play in gears, levers or slides, are present. The linear measuring system enables precise crimp height regulation. Mechanically-caused tolerances of the crimping press, which may be due to, for example, crimping force or temperature fluctuations, are compensated for by the crimp height regulation. With the crimp height regulation the eccentric of the crimping press moves an angular range between 0° and 180° as limits. The crimping press stops at the lower dead center and subsequently reverses. Upper and lower dead center positions can be moved to as desired within the 0°-180° angular range according to the respective crimping tool and crimp contact utilized. Intermediate stop positions are also possible. For realization of this feature only a regulated axis is necessary, and the carriage stroke or crimping height can be programmed. Moreover, the course of the crimping force as a function of the crimping stroke can be represented exactly and is usable for quality control purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is more fully described by the following detailed description when considered with reference to the accompanying figures, in which:
FIG. 1 shows a crimping press with a tool for production of a crimped connection;
FIG. 2 shows the tool with a crimping ram in the lower dead center position;
FIG. 3 shows the tool with the crimping ram in the upper dead center position;
FIG. 4 shows the crimping press with a rotative measuring system and a linear measuring system;
FIG. 5 shows a variant of the arrangement of the linear measuring system;
FIG. 6 shows a schematic illustration of eccentric movement and carriage movement;
FIG. 7 shows a schematic illustration of a regulating circuit for crimp height regulation;
FIG. 8 shows a schematic illustration further detailing the regulating circuit according to FIG. 7; and
FIGS. 9, 10 , 11 , 12 and 13 each show travel curves for movement of the crimping tool.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is designated by 1 a stand, shown without a righthand side wall, upon which a motor 2 and a transmission 3 , which is mounted at the stand 1 , are arranged. Moreover, first guides 4 , by which a crimping bar 5 is guided, are arranged at the stand 1 . A shaft 6 driven by the transmission 3 has an eccentric pin 7 at one end. The crimping bar 5 consists of a carriage 9 guided in the first guides 4 and a tool holder 10 with a retaining fork 11 . The carriage 9 stands in loose connection with the eccentric pin 7 , wherein the rotational movement of the eccentric pin 7 is converted into a linear movement of the carriage 9 . The maximum stroke H of the carriage 9 is determined by the upper dead center and the lower dead center of the eccentric pin 7 . The tool holder 10 actuates a tool 12 , which, together with an anvil 13 belonging to the tool 12 , produces the crimped connection. The shut height at the lower dead centre of the eccentric pin 7 can be precisely adjusted by means of an adjusting screw 14 . If no adjusting wheel is provided at the tool 12 , the crimping height (distance between the anvil 13 and crimping ram at the lower dead center of the eccentric pin 7 ) can be adjusted by the adjusting screw 14 .
FIGS. 2 and 3 show details of the tool 12 for production of a crimped connection. A ram carrier 21 guided in a tool housing 20 has a carrier head 22 , which stands in loose connection with the retaining fork 11 of the tool holder 10 . A first crimping ram 23 and a second crimping ram 24 are arranged at the ram carrier and produce, together with the correspondingly constructed anvil 13 , the crimped connections. FIG. 2 shows the crimping rams 23 , 24 at the lower dead centre position of the eccentric pin 7 , at which the production of the crimped connection is concluded. FIG. 3 shows the crimping rams 23 , 24 in the upper dead center position of the eccentric pin 7 . The maximum ram stroke is determined by the two dead center positions.
FIG. 4 shows the crimping press with a rotative measuring system 25 arranged at the motor 2 , for example an encoder arranged at the motor shaft, and with a linear measuring system 26 , consisting of, for example, a measuring head 27 and a glass scale 28 . The glass scale 28 , which is provided with a graduation, is connected at one end with the tool holder 10 . At the other end the glass scale 28 extends into the measuring head 27 , which is fixedly connected with the stand foot 29 . Moreover, a force sensor 29 . 1 for measuring the crimping force is provided at the tool holder 10 .
FIG. 5 shows a variant of arrangement of the linear measuring system 26 , wherein the measuring head 27 is arranged at a stationary holder 30 and the glass scale 28 is connected at one end with the carriage 9 . In this variant of arrangement there is no compensation for the opening of the crimping press. However, this value is very small relative to the play in the bearings and the levels of rigidity of the transmission, shafts and levers.
In a further variant of arrangement the linear measuring system 26 can be arranged at or in the crimping tool 12 . This arrangement enables a very precise detection of the crimping height.
FIG. 6 shows schematically the movement of the eccentric and the movement of the carriage for a stroke H of, for example, 40 millimeters, wherein the eccentric pin 7 rotates from 0° (uppermost starting position or upper dead center) to 180° (lowermost stop position or lower dead center) and back again to 0°, wherein the path of travel does not run through between 180° and 360°. Start positions deviating from 0° and intermediate stops (split cycles) on the travel between 0° and 180° are also possible. The 180° position of the eccentric pin 7 corresponds with a minimum crimping height (small crimp contacts with small wire cross-sections). In order that re-adjustment is possible, the crimpings should occur before 180°. The point of reversal can lie before 180°, which then corresponds with a maximum crimping height (large crimp contacts with large wire cross-sections). FIG. 6 shows different examples of travel of the carriage 9 or the tool 12 with and without intermediate stops. Intermediate stops are introduced for, for example, centring particular crimp contacts or synchronisation with other cable processing equipment.
FIG. 7 shows a schematic illustration of a regulating circuit for crimping height regulation. The regulating circuit essentially consists of a motor position circuit with the rotative measuring system 25 and a crimping height regulating circuit with the linear measuring system 26 . A signal sc as a target value for the crimping height is predetermined in dependence on the size of the crimp contact to be processed. The signal sc for the target value of the crimping height is converted by means of a first converter 31 into a dimension used in the regulating circuit (transformation of linear values into rotative values). The converted signal is denoted by sc′ and is applied to the input of a travel curve generator 32 . In addition, travel parameters fp, such as, for example, maximum values for speed, acceleration or retardation, are also fed to the travel curve generator 32 . A signal sp as a target value for the motor position is available at the output of the travel curve generator 32 . The signal sp is fed to a first summation point 33 at its + input. A signal xp as an actual value for the motor position is applied to the − input of the first summation point 33 . With respect to regulating technology the signal xp is termed a regulating magnitude and is produced by the rotative measuring system 25 . The signal xwp, which is also termed regulating deviation and which is applied to the input of a switching circuit 34 (explained in more detail in FIG. 8 ), arises at the output of the first summation point 33 from the difference of the signal sp and the signal xp. The signal ym′ is the setting magnitude for the motor 2 , to which the rotative measuring system 25 is coupled. In addition, the signals sd as a target value for motor rotational speed, sb as a target value for motor acceleration and xp as the actual value for the motor position are fed to the switching circuit 34 .
The motor 2 drives a mechanism 35 consisting of the transmission 3 with eccentric pin 7 , guides 4 , crimping bar 5 and tool 12 . With regard to disturbance magnitudes for the regulating circuit, the stand 1 together with the anvil 13 is also to be taken into consideration. The linear measuring system 26 , connected with the tool holder 10 and the stand 1 , produces a signal xc as an actual value for the instantaneous position of the tool holder 10 or for the crimping height. The signal xc for the actual value of the crimping height is converted by means of a second converter 36 into a dimension used in the regulating circuit (transformation of linear values into rotative values). The converted signal is denoted by xc′ and is applied to the − input of a second summation point 37 . The signal sp as the target value for the motor position is also applied to the + input of the second summation point 37 . With respect to regulating technology the signal xc′ is termed regulating magnitude. The signal xwc, which is also termed regulating deviation and is fed to the input of a crimping height regulator 38 , arises at the output of the second summation point 37 from the difference of the signal sp and the signal xc′. The crimping height regulator 38 , which, for example, is provided with a proportional/integral characteristic, produces at its output a signal yc which is also termed setting magnitude and is fed to the switching circuit 34 .
Mechanically induced disturbance magnitudes (opening of the crimping press, play in the bearings and degrees of elasticity or rigidity of the transmission, the shafts and lever) are compensated for by the crimping height regulator 38 and the linear measuring system 26 .
FIG. 8 shows details of the switching circuit 34 , which comprises a position regulator 39 , a rotational speed regulator 40 , a torque regulator 41 and the electronic power unit 42 for the motor 2 . The signal xwp is applied to the input of the position regulator 39 . The position regulator 39 , which is provided with, for example, a proportional characteristic, produces at its output a signal yp which is fed to the + input of a third summation point 43 . The target value signal sd for the motor rotational speed is applied to a further + input and the actual value xd for the motor rotational speed is applied to the − input. xd is produced by means of a third converter 46 , which is provided with a differential characteristic, from the actual value signal xp for motor position. The signal xwd, which is applied to the input of the rotational speed regulator 40 , arises at the output of the third summation point 43 . The rotational speed regulator 40 , which is provided with, for example, a positive/integral characteristic, produces at its output a signal yd which is fed to the + input of a fourth summation point 44 . The target value sb′ for motor acceleration is applied to a further + input and the output signal yc of the crimp height regulator 38 is applied to the − input. The target value sb for the motor acceleration is converted by means of a fourth converter 45 into a dimension used in the regulating circuit. The converted signal is denoted by sb′. The signal xwm, which is fed to the input of the torque regulator 41 , arises at the output of the fourth summation point 44 . The torque regulator 41 , which is provided with, for example, a proportional/integral characteristic, produces at its output a signal ym which is fed to the input of the electronic power unit 42 . In dependence on the signal ym the electronic power unit 42 supplies the motor 2 with the setting magnitude ym′ or with energy.
FIGS. 9 to 13 show travel curves, which are generated by the travel curve generator 32 , as target values predetermination for the movement of the crimping tool 12 on the basis of a first example illustrated by dashed lines and a second example illustrated by chain-dotted lines. The jerk profile jerk=kickback function φ with the values 1, 0, −1) of FIG. 9 causes and influences the rounding of the profile of FIG. 11 . In the shown example the Heaviside function is such that the angular speed of the motor is flattened to half the speed increase or speed decrease, which ensures a jerk-free transition from a changing angular speed to a constant angular speed or conversely. The carriage stroke is dependent on the radius R of the eccentric and on a cosine function of the motor rotational angle. | A crimping press provides increased accuracy and precision. Both a rotative measuring system, such as an encoder arranged at a motor shaft, and a linear measuring system such as, for example, a measuring head and a glass scale, are provided. The linear measuring system may be coupled between a tool holder and the fixed press stand. The measurement values generated by the rotative measuring system and the measuring values of the linear measuring system are fed to a regulating circuit for regulation of crimping height. | 8 |
FIELD OF THE INVENTION
This invention relates to colored detergent bars comprising water soluble polymeric colorants that exhibit excellent non-staining performance on fabrics and other contacted surfaces, including manufacturing and/or washing equipment, are easy to process into the desired detergent bar compositions, and do not exhibit any appreciable harmful effects to the environment. The particular polymeric colorants utilized in this respect are of very high molecular weight (in order to assure staining will not occur on target cleaning surfaces), are extremely water soluble, provide excellent vivid and aesthetically pleasing color shades within the target bar compositions, and are present as liquids or waxy pastes at room and at processing temperatures. The ultimate laundry bar product thus exhibits highly pleasing colors for product distinction as well as for aesthetic purposes.
BACKGROUND OF THE PRIOR ART
All U.S. Patents listed below are fully incorporated herein by reference.
Throughout much of the world, automatic washing machines are not prevalent. In order to regularly clean clothing, many people handwash their garments. Although powders and liquids comprising detergents and/or soaps may be utilized in such handwashing procedures, the standard cleaning compositions utilized for this purpose are in bar form. Laundry bars provide users the ability to more effectively scrub their target garments by permitting the user to concentrate friction and detergent simultaneously on a stained or soiled article of clothing. As such, laundry bars are more appropriate for handwashing procedures, particularly in comparison with powders and liquids, for obvious reasons. Examples of such laundry bars are present within the following U.S. Pat. No. 4,543,204 to Gervasio, U.S. Pat. No. 4,721,581 to Ramachandran et al., U.S. Pat. No. 5,041,243 to Joshi, U.S. Pat. No. 5,043,091 to Joshi et al., U.S. Pat. No. 5,053,159 to Joshi, and U.S. Pat. No. 5,069,825 to Joshi. Such laundry bars differ from household soap and/or personal cleansing bars in that the amount of detergent and/or soap concentrated therein is much greater than for household soaps, etc., alone. Thus, continuous application of such high soap and/or detergent-level laundry bars to human skin would most likely cause skin irritation.
As with most household products, it is highly desirable to provide laundry bars which can easily be identified (from both production source and detergent strength perspectives) and exhibit aesthetically pleasing appearances. One manner of providing such properties is to add color to the final product. Colored laundry bars have been produced, sold, and used in the past; however, such bars have included, primarily, pigments, as coloring agents. Pigments and dyestuffs contribute a number of problems for such laundry bars from processing difficulties to staining possibilities during use. For instance, in order to produce such laundry bars, milling and extrusion procedures are generally followed. The presence of pigments and/or dyestuffs within such machinery causes mechanical problems (due to higher viscosities, solid particles, and/or highly staining compounds) which must be compensated for in different ways. Pigments are generally provided in solid, small particles, which are difficult to handle and which may provide handling problems during production. Also, after the production of certain batches of specifically colored laundry bars, the machinery must be thoroughly cleaned to remove such highly staining pigments and/or dyestuffs (which may create off-color or speckled bars if they remain present during the milling and/or extrusion of a subsequent batch). Pigments do not easily wash away, generally, and thus such cleaning steps may require the utilization of organic solvent compositions which possess their own difficulties and potential problems. Dyestuffs generally require premix production that adds to the complexity of laundry bar production. Furthermore, the colorations provided by pigments are difficult to control from batch to batch (and thus uniform colorations are rather difficult to produce on an industrial scale). Dyestuffs are generally ionic in nature and thus are not readily compatible with other laundry bar constituents (such as surfactants, perfumes, preservatives, and the like). Pigments, dyes, and dyestuffs also comprise heavy metal components at times which provide environmental and health issues. Additionally, the general color appearances provided by pigments are dull due to the adsorption and scattering of light by the constituent solid particles.
Upon use of such pigment- and/or dyestuff-containing laundry bars, such coloring agents have been found to cause staining of the user's skin as well as upon the washboard and target garments themselves. Furthermore, most pigments include metals or other components which, upon introduction within wastewater from a washing procedure, have been known to cause environmental problems. Thus, it is important to provide a manner of coloring laundry bars which is easy to incorporate within standard milling and extrusion procedures, facilitates cleaning from such necessary machinery, fabrics, human skin, and other washing equipment, and which is environmentally friendly. To date, no improvements in the laundry bar industry have been accorded by the prior art.
OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION
It is an object of the subject invention to provide colored laundry bars that exhibit substantially no staining on target fabrics, the user's skin, and the manufacturing equipment utilized to produce such laundry bars. It is a further object of the subject invention to provide colorants that have no heavy metal and have no dye dust involved in the manufacturing process and thereby are relatively easy to use and produce. It is yet a further object of this invention to provide a colored laundry bar exhibiting the above characteristics and which also exhibits stable and aesthetically pleasing colorations throughout the bar even after repeated use within an aqueous environment.
Accordingly, this invention encompasses a colored laundry bar comprising at least one compound selected from the group consisting of a soap, a detergent, a surfactant, a tenside, and any mixtures thereof, preferably in an amount of between about 25 and 80% by weight of the total weight of the bar, most preferably between about 30 and 60%, and at least one colorant present in an amount of from about 0.001 to about 2.0% by weight of the total weight of the bar, wherein said colorant is a water-soluble polymeric colorant having from about 3 to 50 moles of oxyalkylene constituents per polymer chain.
Such a specific colored laundry bar composition has never been produced or taught within the pertinent prior art. In fact, the belief has been in the past that such high molecular weight polymeric colorants could not function properly within laundry bar compositions due to the extremely high water solubility and liquid nature of the colorants themselves. Since the laundry bars are utilized within procedures which require a great deal of repeated contact with water, it is rather difficult to retain stable colorations throughout such laundry bars including these extremely water soluble polymeric colorants. Thus, previous attempts at incorporating the desired high molecular weight polymeric colorants within such solid laundry bars have either been unsuccessful or nonexistent until now.
DETAILED DESCRIPTION OF THE INVENTION
The particular high molecular weights and degree of oxyalkylation of the colorants within the inventive laundry bars are necessary to provide the desired low staining ability. Polymeric colorants in general have a propensity to color any surface to which they are contacted, adhered, or incorporated. The currently discussed polymeric colorants were developed to provide temporary, easily removable, but highly effective colorations to certain substrates, including fabrics, yams, liquids, and the like. These high molecular weight colorants do not readily react with substrates and are extremely water soluble. Thus, the colorants are, as noted above, easily removed from certain substrates through a simple aqueous rinsing procedure. The same holds true for human skin, metal surfaces, plastics, concrete, and other common substrates. As a result, such colorants do not exhibit any appreciable staining of target substrates cleaned through utilization of the inventive laundry bars.
The problem with utilizing such colorants as now taught is that the water solubility is difficult to control, particularly when the ultimate laundry bar composition comprises components of which a vast majority is water (e.g., soaps and detergents comprise or easily pull water from the atmosphere) and the bar is generally in constant contact with water during use. However, the colorants have been shown to remain quite stable in composition dispersed throughout the soap and/or detergent formulation of the laundry bar itself and thus do not exhibit any appreciable loss or alteration in color strength or shade.
The particularly preferred colorants defined above are produced by Milliken & Company and have been used solely in the past within liquid compositions, such as liquid detergents, liquid fabric softeners, liquid antifreezes, and the like. Again, the high molecular weight and extremely high water solubility of such colorants are much more appropriate for such liquid applications due to the ability to provide uniform, stable color throughout the target composition and yet not exhibiting any unwanted discolorations to target substrates upon use thereof. Such colorants have not been utilized as colorants within solid compositions to any appreciable degree, as noted above.
In particular, these colorants provide the laundry bar composition of the invention with improved resistance to staining of fabrics including one or more of cotton, wool, acetate, polyester, polyamide, acrylics and viscose so that all, or virtually all of the colorants will not be left on the fabric by means of normal handwashing procedures. Furthermore, such colorants exhibit superior brightness, are less toxic to humans due to relatively high molecular weight of the colorants and the lack heavy metals, as compared with dyestuffs and/or pigments. Additionally, these colorants are present as low viscosity liquids or waxy pastes (at room temperature, at least) and are thus much easier to handle than dyestuff and pigment solids and powders.
The particularly preferred colorants of this invention comply with the following structure (I)
R{A[(B) n ] m } x (I)
wherein
R is an organic chromophore;
A is a linking moiety in said chromophore selected from the group consisting of N, O, S, SO 2 N, SO 3 N, and CO 2 ;
B is an alkyleneoxy constituent contains from 2 to 4 carbon atoms;
n is an integer of from 12 to about 50;
m is from 1 to 4; and
x is an integer of from 1 to about 5.
These colorants are highly water soluble due to the high degree of alkoxylation (from between 3 and 50 moles per polymer chain). Such oxyalkylene groups include ethyleneoxy (EO), propyleneoxy (PO), butyleneoxy (BO), and so forth. Furthermore, such colorants are, when present in their substantially pure, undiluted states, generally either liquid or waxy paste at room temperature. The organic chromophore is, more specifically, one or more of the following types of compounds: azo, diazo, disazo, trisazo, diphenylmethane, triphenylmethane, xanthene, nitro, nitroso, acridine, methine, styryl, indamine, thiazole (including benzothiazole), oxazine, stilbene, phthalocyanine, or anthraquinone. Preferably, R is one or more of azo, diazo (including, without limitation, phenyl-, naphthol-, benzothiazole-, and acid-based chromophores), triphenylmethane, methine, anthraquinone, or thiazole based compounds. Such a group may produce coloring effects that are evident to the eye; however, optical brightening chromophores are also contemplated in this respect. Group A is present on group R and is utilized to attach the polyoxyalkylene constituent to the organic chromophore. Nitrogen is the preferred linking moiety. The polyoxyalkylene group is generally a ethylene oxide, propylene oxide, or combinations thereof. Preferably ethylene oxide is present in the major amount, and most preferably the entire polyoxyalkylene constituent is ethylene oxide.
The preferred number of moles (n) of polyoxyalkylene constituent per polyoxyalkylene chain is from 3 to 50, more preferably from 20 to 30. Also, preferably two such polymeric chains are present on each polymeric colorant compound (x, above, is preferably 2). In actuality, the number of moles (n) per polymeric chain is an average of the total number present since it is very difficult to control the addition of specific numbers of moles of alkyleneoxy groups. The Table below lists some particularly preferred colorants for utilization within the inventive laundry bars in relation to Structure (I), above, and is not intended to limit the types of colorants available within the inventive laundry bar formulations. The degree of alkoxylation is listed as ranges (under n) due to the inexactness of applying and measuring such moieties within the final colorant products:
TABLE 1
Preferred Poly(oxyalkylenated) Colorants
Col. #
R
A
B
n
m
x
1
Phenyl Diazo
SO 3 N
EO
3-6
3
2
2
Anthraquinone
N
1-3 PO; 2-5 EO
3-5
2
2
3
Benzothiazole
N
EO
16-20
2
1
Diazo
4
Methine
N
EO
16-20
2
1
(methoxy-capped)
5
Phenyl Diazo
N
EO
16-20
2
1
6
Acid Diazo
N
EO
16-20
2
1
The term “laundry bar” is intended to encompass a solid composition (of any shape or configuration, but preferably of a three-dimensional rectangle) of at least one soap, detergent, surfactant, and/or tenside (as well as other components, such as builders, optical brighteners, fillers, and the like) which is utilized primarily for the purpose of handcleaning and/or handwashing garments. Such bars must be very firm to withstand the frictional pressures applied to target fabrics during cleaning (the vigorous rubbing over the target garment, for example) so as to retain its structural integrity during use. Also, the bar must not be too firm as to either overly abrade the bar or the target garment. The above-referenced U.S. Patents provide more information as to the particular laundry bars discussed herein and thus encompassed by the above definition. Specifically, such laundry bars should comprise from about 25 to 80% by weight, most preferably from about 30 to about 60% by weight (from about 15 to 40 parts) of active cleaning ingredient (i.e., soap, detergent, surfactant, tenside, or any mixtures thereof). Such amounts are extremely high as compared with standard personal cleansing bars; the utilization of such high amounts for standard hand and/or body washing would be detrimental to the user as such compounds cause skin irritation. Other than the above-mentioned colorants, the laundry bar formulation may also comprise any of the following components (in % by weight of the total composition): 30-40% of builders (such as, for example, sodium tripolyphosphate, sodium silicate, and the like), 40-50 percent of fillers and binders (such as, for example, calcium carbonate, clays, such as bentonite, sodium sulfate, starch, magnesium sulfonate, talc, and the like), and 1-10 percent of other additives (such as glycerine, paraffin wax, foam boosters, perfumes, enzymes, dye inhibitors, and antibacterial agents). Furthermore, the amount of free water within the initially produced composition preferably should not exceed about 15%. Any higher amounts will result in too soft a bar for proper utilization as a laundry bar.
Suitable soaps in this invention include any of the well known salts of fatty acids produced by combining a cation-hydroxide (as one example) with a fatty acid. Such fatty acids generally have from 8 to about 24 carbon atoms in chain length, either straight or branched, preferably from about 10 to about 20 carbons in length. Preferred cations within such salts include, without limitation, metals, such as potassium and sodium, and other components such as ammonium and alkylammonium cations. The fatty acids are preferably obtained from natural resources, such as plant or animal esters, including, without limitation, palm oil, coconut oil, peanut oil, corn oil, soybean oil, palm kernel oil, fish oil, lard, grease, tallow, castor oil, and the like. Such ingredients within the inventive laundry bars are basically the same as those listed within U.S. Pat. No. 5,952,289 to Wise et al.
The detergents, tensides, and surfactants are also standard constituents within the fabric cleaning art. Such may be derived from nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and zwitterionic surfactants. Any alkyl- or alkenyl-groups listed below are from C 1 to C 12 in length unless otherwise noted. Among the nonionic surfactants are included ethoxylated or propoxylated fatty alcohols and acids, ethoxylated or propoxylated alkyl phenols, fatty acid amides, such as diethanolamides, amine oxides, phosphine oxides, polyglucosides, sulfoxides, polyoxyethylene-polyoxypropylene block copolymers, and silicon glycols. Anionic surfactants include linear or branched alkylbenzene, toluene, xylene, or naphthalene sulfonates, alkyl sulfonates and sulfates, fatty ether sulfates, ammonium ethoxysulfate, sodium ethoxysulfate, phosphate esters, alkyl and alkylenyl carboxylic acids and fatty acids (and their salts), ethoxylated alcohol sulfates, alkyl glyceryl ether sulfonates, α-sulfonated fatty acid esters, 2-acyloxyalkane-1-sulfonates, olefin and paraffin sulfonates, and β-alkoxyalkane sulfonates. Possible cationic surfactants include quaternary ammonium salts, amines, and amine oxides. Suitable amphoterics include mixed C 8 amphocarboxylates, cocoamphocarboxyglycinates, and derivatives of aliphatic heterocyclic secondary and tertiary amines. Suitable zwitterionics include betaines, such as cocoamidopropyl betaine, derivatives of quaternary ammonium, phosphonium, and sulfonium compounds.
Other possible components within such detergent compositions include builders/softeners, solvents, hydrotropes, pH adjusters, bleaches, bleach activators, optical brighteners, abrasives, suds boosters, suds depressors, soil suspending/release agents, anti-redeposition agents, enzymes, enzyme stabilizers, chlorine scavengers, perfumes, anti-corrosion agents, fungicides, germicides, fillers (such as smectite clays, and the like), and other colorants (such as reactive, acid, solvent, and the like dyes). Such compounds are well known within the detergent art.
Also contemplated and of particular importance within this invention is the process for manufacturing such detergent laundry bars. It has been determined that the initial laundry bar components are generally in powder form. Such components thus must be are premixed together with other liquid components, including perfumes, polymeric colorants, and water, added thereafter. After the mixing of the subsequent formulation, it is then amalgamated, milled, extruded and/or plodded under vacuum to form a solid composition, which is then cut to its desired form. Since the polymeric colorants are in liquid form, they are more versatile and easier to utilize within laundry bar manufacturing processes. Using standard bar-making equipment and well-known methods to produce the laundry bar product, the polymeric colorants can always be added at the last step of mixing process, which is much more convenient and less complex from a manufacturing perspective. The particularly preferred process comprises the following steps:
(a) admixing the soap, detergent, tenside, and/or surfactants with any other components, except the colorants;
(b) adding the desired polymeric colorants to the mixture of step “a”;
(c) optionally milling the mixture from step “b” to produce flakes of the milled product;
(d) extruding the product from step “b” or step “c” to produce an elongated solid product; and
(e) cutting and shaping the product from step “d” to form the desired laundry bar.
Such a simplified method of producing an actual colored laundry bar is highly desirable from a complexity standpoint and permits a reduction in cost for the producer and ultimately the user.
PREFERRED EMBODIMENTS OF THE INVENTION
As mentioned above, the laundry bar compositions of the present invention are characterized by significantly reduced staining of fabric. Fabric staining may be determined by measuring the ΔE cmc value of the residue colorant stain on a target substrate. This ΔE cmc value is directly related to fabric staining after laundering. The numerical value of ΔE cmc as is determined in this invention can vary from 0 to 5; preferably from 0 to about 1.
As one example, the stain on cotton terry fabric, which has a very rough surface, may be measured by rating the residue stain visually. The numerical value for the staining on cotton terry, on a scale of zero to 10, as determined in this invention can vary from 0 to 2; preferably from 0 to about 1.
The following examples serve to illustrate the subject matter of the present invention and are not to be construed as limiting the scope of the invention. All parts and percentages that are set forth are by weight unless otherwise indicated.
All of the preferred embodiments below comprised the following laundry bar base material components in the amount listed by parts:
BASE MATERIAL COMPOSITION
Component
Amount in Parts
C 9 -C 18 alkyl benzene sulfonate
19
Soap (sodium salt of C 12 -C 18 fatty acid)
10
Sodium tripolyphosphate
14
Sodium Carbonate
22
Sodium Silicate
7
Starch
10
Magnesium Sulfate
4
Water
14
EXAMPLE 1
5 gm of a 20%/80% mixture of Colorants #1 and #2 from TABLE 1, above was added to 10 kg of non-colored laundry bar base material in a ribbon mixer and blended for a short length of time to adequately disperse them in the mixture to produce a uniformly green colored material (the concentration of the colorant to base material was about 0.2%). The mixture is fed through roll mills to provide more intimate mixing. Roll mills used for this purpose are those typical of soap milling process. The milled product was then extruded by the plotter from Sunlab International to form a homogeneous bar.
EXAMPLES 2-4
The following polymeric colorants or their blends (at the concentration of 0.05, 0.1, 0.2 and 0.3 %, respectively) were mixed with the non-colored laundry bar base material by using standard bar-making equipment as mentioned in Example 1.
TABLE 2
Example #
Type of Colorant(s)
Conc. of Colorant
Color
2
50%/50% mixture of
0.05%
Purple
Colorants #2 and #3
3
Colorant #2
0.05%
Blue
4
Colorant #2
0.1%
Dk Blue
Commercially available comparative laundry bars were tested for stability and staining as discussed below.
Stain Measurements for Examples and Comparatives
100% cotton 2.94 combed broadcloth (from TestFabrics, Incorporated) with the dimensions measuring 10 cm by 10 cm was prewashed, dried, and ironed based on the protocol of the process described in Test Method ASTM D 4265. A 100% cotton terry cloth (from Test Fabrics, Incorporated) with the dimensions measuring 10 cm by 4 cm was also prepared by the same protocol for further testing.
The sample cloth pieces were individually pre-immersed in water for 5 minutes to thoroughly wet the fabric. The fabric was taken out from the water and scrubbed with the laundry bar sample till it was fully covered with soap on both sides. These samples were individually kept at room temperature inside enclosed plastic bags for 24 hours before being was washed and rinsed with water until the rinse water exhibited no visible color. Finally, the testing fabrics sample were dried at room temperature. The above testing procedure can also be repeated for multi-cycle washability tests, if desired.
The cotton terry samples were placed side-by-side for comparisons. The cotton broadcloth fabrics were smoothed with a steam iron for further measurements.
After the washing procedures were then completed, the samples were analyzed for residual staining using CIELAB coordinates measured by means of an Ultrascan™ XE color computer from Hunterlab. The color computer was adjusted to the following settings:
1. 10 degree viewer
2. D65 illuminant
3. ½ inch diameter viewing aperture
4. UV filter
The instrument was then calibrated to zero reflectance with a black tile and 100% reflectance with a white tile. Both the control (white fabric) and the stained test samples were evaluated according to the following procedure: Each fabric test sample was folded lengthwise and widthwise to present a four-fold thickness of fabric to be inserted into the light source of the instrument. A white tile was then placed over the fabric sample and the CIELAB data was obtained from the color computer. ΔEcmc data was used as an indication for any residual staining of the test and comparison fabric samples. The residual stain on the sample fabric was then rated on a scale of 0 to 10. The following guidelines below are used to give a numeric value to the staining on cotton terry fabrics:
0 - - - No stain apparent on the fabric
1 - - - Slight stain apparent, approximately 10% depth of original
2 - - - Slight stain apparent, approximately 20% depth of original
3 - - - Moderate stain, approximately 30% depth of original
4 - - - Moderate stain, approximately 40% depth of original
5 - - - Moderate stain, approximately 50% depth of original
6 - - - Severe stain, approximately 60% depth of original
7 - - - Severe stain, approximately 70% depth of original
8 - - - Severe stain, approximately 80% depth of original
9 - - - Severe stain, approximately 90% depth of original
10 - - - 100 % of original stain remaining
The comparative samples tested in this experiment were the following with the actual color and source listed (these were all either dyestuff or pigment-based colored laundry bars):
Comparative A—Trojan® (Green, from Colgate-Palmolive)
Comparative B—Dobi® (purple, from Lion)
Comparative C—Trojan® (Blue, from Colgate-Palmolive)
Comparative D—Fab® Total (Dark Blue, from Colgate-Palmolive)
The results of Experimental Table below illustrate typical washability (on 100% cotton) of the commercial laundry bar samples mentioned above as compared with those from the samples with similar shade and color depth made by using the polymeric colorants (Examples 1-4, above).
Experimental Table 1
Stain Data for both commercial laundry bar and the samples from
polymeric colorants on 100% cotton fabric
Color
Delta E cmc
shade
Sample
First Cycle
Second Cycle
Green
Comparative A
0.42
3.44
Example 1
0.21
0.37
Purple
Comparative B
1.05
2.15
Example 2
0.47
1.22
Blue
Comparative C
1.06
2.28
Example 3
0.94
1.35
Dark Blue
Comparative D
1.59
4.36
Example 4
0.72
1.29
The results clearly evince the superior properties of the inventive laundry bars in comparison with the commercially available types comprising dyestuffs, pigments, or mixtures thereof
The results of Experimental Table 2 illustrate the washability test results on cotton terry.
Experimental Table 2
Stain Data for both commercial laundry bars and the samples from
polymeric colorants on cotton terry
Color
shade
Sample
Stain scale
Green
Comparative A
2
Example 1
1
Purple
Comparative B
3
Example 2
1
Blue
Comparative C
3
Example 3
1
Dark Blue
Comparative D
4
Example 4
1
The polymeric colorants illustrated in above two tables clearly provided superior staining properties over the commercial laundry bars shown in above tables. Generally, the fabric (both 100% cotton and cotton terry) staining was as much as 3-4 times better for the polymeric colorants of the above tables.
While specific features of the invention have been described, it will be understood, of course, that the invention is not limited to any particular configuration or practice since modification may well be made and other embodiments of the principals of the invention will no doubt occur to those skilled in the art to which the invention pertains. Therefore, it is contemplated by the appended claims to cover any such modifications as incorporate the features of the invention within the true meaning, spirit, and scope of such claims. | Colored detergent bars are provided comprising water soluble polymeric colorants that exhibit excellent non-staining performance on fabrics and other contacted surfaces, including manufacturing and/or washing equipment, are easy to process into the desired detergent bar compositions, and do not exhibit any appreciable harmful effects to the environment. The particular polymeric colorants utilized in this respect are of very high molecular weight (in order to assure staining will not occur on target cleaning surfaces), are extremely water soluble, provide excellent vivid and aesthetically pleasing color shades within the target bar compositions, and are present as liquid or waxy pastes at room and at processing temperatures. The ultimate laundry bar product thus exhibits highly pleasing colors for product distinction as well as for aesthetic purposes. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/063,334 filed Oct. 13, 2014 which is incorporated herein by reference in its entirety as if fully set forth herein.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with government support under DE022838 awarded by The National Institute of Dental and Craniofacial Research (National Institute of Health). The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] Dental caries and periodontal diseases are among the most common chronic diseases affecting billions of people around the world. These two diseases are the leading cause of tooth loss which severely influences the quality of life of patients. Conventional approaches to treat those diseases do not perform biological repair or regeneration. Therefore, these treatments cannot fully recover the biological functions of normal teeth. Tissue engineering approaches have been introduced as an alternative strategy to restore lost tissues (dentin, pulp, periodontal ligament, etc.). This approach has an advantage over traditional strategies in that after healing, the damaged/lost tissues are restored to their original state. Clearly, regeneration is the most desirable outcome for any therapy. Significant progress of dental tissue regeneration has been made in recent years. However, the regeneration of well-organized dental tissues, which are crucial to perform their biological functions, has never been achieved. One of the main barriers is the difficulty of developing suitable biomaterials/matrix to guide cell growth, differentiation, and new tissue formation.
[0004] According to the National Institute of Dental and Craniofacial Research (NIDCR), dental caries and periodontal diseases affect 92% and 8.5%, respectively, of adults from 20 to 64 years old in USA. Current clinical treatments have various limitations and cannot fully recover the biological function of the original tooth. While tissue engineering strategies have been proven, the potential to regenerate functional dental tissues with the same structure of the natural dental counterparts has not been accomplished. Without the proper structure, the engineered tissue cannot fulfill its biological function.
SUMMARY OF THE INVENTION
[0005] The claimed invention is directed to a unique technology for preparing a biomimetic synthetic matrix that modulates the formation of well-ordered dental tissues in the same manner as natural tooth tissues. The technology is capable of precisely tailoring the physical architecture of the matrix including, the diameter of nanofibers, pore size, pore density and pore distribution. The formed synthetic matrix therefore, truly mimics natural dental extracellular matrix (ECM) and provides an excellent environment to guide the formation of well-organized dental tissue, including tubular dentin and periodontal ligaments. In summary, the technology is used to prepare biomimetic matrix and regenerate functional dental tissues; thereby, improving the life quality of patients who have lost/damaged dental tissues. The claimed invention is directed to the preparation of a synthetic biomimetic matrix which will be developed for clinical treatment to regenerate normal structured dental tissues for patients.
[0006] An embodiment of the invention is directed to a matrix comprising a layer having a predetermined porosity, wherein the layer is made of electrospun polymer fibers.
[0007] A further embodiment of the invention is directed to a method of producing a matrix, the method comprising: electrospinning a liquefied polymer onto an electrode hence providing a layer having a predetermined porosity. In certain embodiments of the invention, the precipitation electrode comprises a rotating mandrel.
[0008] In an embodiment of the invention, an electrospinning process is combined with laser ablation to create a porous matrix.
[0009] In an embodiment of the invention, the liquefied polymer is a biocompatible melted polymer.
[0010] An aspect of the invention is directed to a method of replacing a portion of a dental tissue, comprising: providing a porous matrix as described herein; and connecting the porous matrix to existing dental tissue.
[0011] In an embodiment of the claimed invention, the combination of electrospinning and laser ablation technology is used to synthesize a biomimetic matrix for well-ordered pulpodentin and periodontal tissue regeneration. Specifically, the electrospinning process is used to create a matrix layer and the laser ablation step is used to create the pores, or tubules, of a predetermined size in the matrix.
[0012] In an embodiment of the claimed invention, the porosity of the matrix changes along with the depth of the matrix.
[0013] In certain embodiments, the diameter of the pores of the matrix changes along the depth of the matrix. In some embodiments, the pores on the top surface of the matrix have a smaller diameter than the pores at the bottom surface of the matrix. In other embodiments, the pores on the bottom surface of the matrix have a smaller diameter than the pores on the top surface of the matrix. In certain embodiments, the pore size changes in a contiguous manner from the top of the matrix to the bottom of the matrix.
[0014] An embodiment of the claimed invention is further directed to a method to make new dental tissue comprising, applying dental stem cells onto a porous matrix and allowing the dental stem cells to develop into odontoblasts, wherein the dental stem cells comprise cells from an enamel organ and/or a pulp organ.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
[0016] FIG. 1 depicts the following: (A) is an SEM image of a human-tubular matrix; (B) is an SEM image of a synthetic-tubular-gelatin matrix; (C) is a magnification of the image of FIG. 1A ; and (D) is a confocal image of a synthetic-tubular-gelatin matrix;
[0017] FIG. 2 shows multiple configurations (A to F) of a synthetic-tubular-gelatin matrix;
[0018] FIG. 3 depicts the following: (A) is an SEM image of a human dentin matrix; and (B) is an SEM image of a synthetic-tubular-gelatin matrix;
[0019] FIG. 4 shows SEM images of a synthetic-tubular-gelatin matrix (A) and a synthetic-tubular-matrix after mineralization (B), respectively;
[0020] FIG. 5 depicts the following: (A) is an SEM image of a dental-pulp stem cell cultured on a synthetic-gelatin matrix without tubules; (B) is an SEM image of a dental-pulp stem cell cultured on a synthetic-tubular-gelatin matrix; (C), (D) and (E) are confocal images of dental-pulp stem cells on a synthetic-tubular-gelatin matrix after being cultured in a conditioned medium for 48 hours;
[0021] FIG. 6 shows cross-sectional views of dental-pulp stem cells cultured on a synthetic-tubular-gelatin matrix (A and B); and cross-sectional views of dental-pulp stem cells cultured on a synthetic-gelatin matrix without tubules (C and D);
[0022] FIG. 7 shows side views showing regenerated tubular-dentin structure on a synthetic-tubular-gelatin matrix after in-vitro culture for two weeks (A and B); and side views showing regenerated tubular-dentin structure on a synthetic-gelatin matrix without tubules after in-vitro culture for two weeks (C and D);
[0023] FIG. 8 shows an SEM image of dentin-pulp tissue cultured in vitro for two weeks on a synthetic-tubular-gelatin matrix (A); and an SEM image of dental-pulp tissue cultured in vitro for two weeks on a synthetic-gelatin matrix without tubules (B);
[0024] FIG. 9 shows side views showing regenerated tubular dentin and pulp tissues after in-vivo culturing for four weeks on a synthetic-tubular-gelatin matrix (A and B); and side views showing regenerated tubular dentin and pulp tissues after in vivo culturing for four weeks on a synthetic-gelatin matrix without tubules (C and D);
[0025] FIG. 10 shows SEM views of regenerated tissues after in-vivo culturing for four weeks on a synthetic-tubular-gelatin matrix (A) and a synthetic-gelatin matrix without tubules (B), respectively;
[0026] FIG. 11 shows Haemotoxylin and Eosin (“H&E”) staining of dentin-pulp stem cells on a synthetic-tubular-gelatin matrix construct after being subcutaneously implanted into nude mice for 4 weeks; and
[0027] FIG. 12 shows von Kossa staining of dentin-pulp stem cells on a synthetic-tubular-gelatin matrix after being subcutaneously implanted into nude mice for four weeks.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0028] Various embodiments of the present invention will now be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
[0029] FIG. 1A is a scanning electron microscope (“SEM”) image of human dentin 10 . The human dentin 10 includes a matrix 12 formed from a plurality of collagen fibers 14 . The matrix 12 also includes a plurality of pores or tubules 16 formed through the matrix 12 . FIG. 1B is an SEM image of a synthetic-tubular-gelatin matrix 100 , which is a biomimetic matrix approximating the human dentin 10 . The synthetic-tubular-gelatin matrix 100 comprises a matrix 102 formed from a plurality of gelatin nanofibers 104 (best seen in FIG. 1C ). The gelatin nanofibers 104 mimic the collagen fibers 14 (the same range of size and almost the same chemical composition) of the human dentin 10 . A plurality of tubules 106 are formed within the matrix 102 . In one embodiment, the plurality of tubules 106 may be formed via laser ablation. The plurality of tubules 106 mimics the plurality of tubules 16 . The plurality of tubules 106 can be formed at various distances from one another and with various diameters depending on various design considerations. In one embodiment, a diameter of one of the plurality of tubules 106 is approximately 2-3 μm, which is approximately the same diameter of the plurality of tubules 16 . In certain embodiments, the diameter of one of the plurality of tubules 106 ranges from 2-5 μm. FIG. 1C is a magnification of an SEM image showing one of the plurality of tubules 106 formed in the plurality of gelatin nanofibers 104 .
[0030] FIG. 1D is a confocal image of the synthetic-tubular-gelatin matrix 100 , which shows a top view 108 , a side view 110 , and a side view 112 of the synthetic-tubular-gelatin matrix 100 . The side view 110 shows that plurality of tubules 106 pass completely through the synthetic-tubular-gelatin matrix 100 and that diameters of the plurality of tubules 106 changes along a length of the plurality of tubules 106 (similar to that of plurality of tubules 16 from a near-pulp region to a dental-enamel junction “DEJ” region).
[0031] Referring now to FIGS. 2A-2F , control of a density of the plurality of tubules 106 and of a diameter of the plurality of tubules 106 is shown. FIGS. 2A-2C demonstrate that a tubular density—i.e., the number of tubules 106 per area—can be controlled. FIG. 2A depicts a relatively dense formation of tubules 106 , while FIG. 2C depicts a relatively less dense formation of tubules 106 . FIG. 2B depicts a density of tubules 106 between the densities shown in FIGS. 2A and 2C . The density of the tubules 106 may be varied in accordance with various design parameters. In addition to controlling the density of the tubules 106 , the diameters of the tubules 106 may also be controlled as shown in FIGS. 2D-2F . As shown in FIGS. 2D-2F , the diameter of the tubules 106 may be varied between, for example, 300 nm and 30 μm. The diameter of the tubules 106 may be varied in accordance with various design parameters. In one embodiment, diameter variation is accomplished by manipulating, for example, an amount of time the laser is focused on the matrix 100 , an amount of energy supplied to the matrix 100 by the laser, and the like.
[0032] FIGS. 3A and 3B show SEM images of the human dentin 10 and the synthetic-tubular-gelatin matrix 100 , respectively. As shown, the synthetic-tubular-gelatin matrix 100 mimics tubule diameter size, tubule gradient (i.e., a tapering of the tubule along its length, which results in a frustoconical shape), and tubule density.
[0033] FIGS. 4A and 4B show SEM images of the synthetic-tubular-gelatin matrix 100 before and after mineralization, respectively. As shown in FIG. 4B , the plurality of gelatin nanofibers have become mineralized nanofibers 105 . The process of adding mineral to matrix is referred to as “mineralization.”
[0034] FIG. 5A shows a dental pulp stem cell (“DPSC”) 202 cultured on a synthetic-gelatin matrix 200 . The synthetic-gelatin matrix 200 differs from the synthetic-tubular-gelatin matrix 100 in that it does not include a plurality of tubules. FIG. 5B shows a DPSC 114 cultured on the synthetic-tubular-gelatin matrix 100 . It is shown that a portion 116 of the DPSC 114 has descended into the tubule 106 . As compared to DPSC 202 , the DPSC 114 has obtained a superior attachment to the matrix.
[0035] FIGS. 5C, 5D and 5E are confocal images of the synthetic-tubular-gelatin matrix 100 of FIG. 5B . The lighter portion of the image in FIG. 5C depicts the DPSC 114 . FIG. 5C shows a top view 118 , FIG. 5E shows a side view 120 , and FIG. 5D shows a side view 122 of the synthetic-tubular-gelatin matrix 100 . As shown in the side view 120 , the portion 116 of the DPSC 114 has descended into the tubule 106 to form a secure attachment to the synthetic-tubular-gelatin matrix 100 .
[0036] FIG. 6A is a cross-sectional view of DPSCs 324 cultured on a synthetic-tubular-gelatin matrix 300 . FIG. 6B is an enhanced view of FIG. 6A , where the synthetic-tubular gelatin matrix 300 has been highlighted to better show a matrix 302 and tubules 306 , and the DBSCs 324 have been highlighted to better show F-actins 326 (shown as light gray layers stacked on top of the synthetic-tubular-gelatin matrix 300 ) and nuclei 328 (shown as bright spots within the light gray layers).
[0037] FIG. 6C is a cross-sectional view of DPSCs 352 cultured on a synthetic-gelatin matrix 350 . FIG. 6D is an enhanced view of FIG. 6C , where the synthetic-gelatin matrix 350 has been highlighted to better show the matrix 350 , and the DPSCs 352 have been highlighted to better show F-actins 356 (shown as light gray layers stacked on top of the synthetic-tubular-gelatin matrix 350 ) and nuclei 358 (shown as bright spots within the light gray layers). FIGS. 6A and 6B show a significant increase in DPSC 324 growth and a significant improvement in the interface between the DPSCs 324 and the synthetic-tubular-gelatin matrix as compared to the DPSCs 352 shown in FIGS. 6C and 6D .
[0038] FIG. 7A is a side view showing regenerated DPSCs 424 on a synthetic-tubular-gelatin matrix 400 after in-vitro culture for two weeks. FIG. 7B is a magnification of the image of FIG. 7A . F-actins 426 can be identified by the lighter gray colors of the image and nuclei 428 can be identified by the darker spots of the image. FIG. 7C is a side view showing regenerated DPSCs 452 on a synthetic-gelatin matrix 450 after in-vitro culture for two weeks. FIG. 7D is a magnification of the image of FIG. 7C . F-actins 456 can be identified by the lighter gray colors of the image and nuclei 458 can be identified by the darker spots of the image. FIGS. 7A and 7B show a significant increase in DPSC 424 growth and a significant improvement in the interface between the DPSCs 424 and the synthetic-tubular-gelatin matrix as compared to the DPSCs 452 shown in FIGS. 7C and 7D .
[0039] FIG. 8A is an SEM image of DPSCs 524 cultured in vitro for two weeks on a synthetic-tubular-gelatin matrix 500 . FIG. 8B is an SEM image of DPSCs 552 cultured in vitro for two weeks on a synthetic-gelatin matrix 550 . FIG. 8A shows an improved interface between the DPSCs 524 and the synthetic-tubular-gelatin matrix 500 as compared to an interface between the DPSCs 552 and the synthetic-gelatin matrix 550 .
[0040] FIG. 9A shows regenerated DPSCs 624 after in-vivo culturing for four weeks on a synthetic-tubular-gelatin matrix 600 . FIG. 9B is a magnification of the image in FIG. 9A . FIG. 9C shows regenerated DPSCs 552 after in-vivo culturing for four weeks on a synthetic-tubular-gelatin matrix 650 . FIG. 9D is a magnification of the image in FIG. 9C .
[0041] FIG. 10A is an SEM image showing regenerated DPSCs 724 after in-vivo culturing for four weeks on a synthetic-tubular-gelatin matrix 700 . FIG. 10B is an SEM image showing regenerated DPSCs 752 after in-vivo culturing for four weeks on a synthetic-gelatin matrix 750 .
[0042] FIG. 11 shows Haemotoxylin and Eosin (“H&E”) staining of DPSCs 824 and a synthetic-tubular-gelatin matrix 800 after being subcutaneously implanted into nude mice for four weeks. A tubular dentin tissue was successfully regenerated, and odontoblasts were aligned in a well-organized way along the tubular matrix, similar to that of natural tubular dentin.
[0043] FIG. 12 shows von Kossa staining of DPSCs 924 and a synthetic-tubular-gelatin matrix 900 after being subcutaneously implanted into nude mice for four weeks. A mineralized tubular dentin tissue was clearly observed from the von Kossa staining.
WORKING EXAMPLES
[0044] Nanofibrous synthetic matrix is fabricated by an electrospinning process using a high-voltage power supplier (Model: ES30P-SW, Gamma High Voltage Research Inc.). The diameter of the matrix nanofiber was tailored by the polymer concentration and electrospinning speed. Next, a Leica Laser Microdissection 7000 (Leica microsystem, Germany) will be used to generate tubular structure on the nanofibrous matrix. The matrix will be tiled flat onto a glass coverslip. A software Leica laser microdissection V7.4.1 was used to design the pore distribution pattern. During the laser ablation process, the pore size was controlled by the laser aperture and laser pulse energy, and the pore density was modulated by the laser frequency and speed. For a typical experiment to generate the tubular architecture, the operation parameters of the equipment are as follows: laser aperture 30 Hz, laser pulse energy 30 Hz, laser speed 40 Hz, and laser pulse frequency 37 Hz. Using these parameters, more than 130000 tubular pores were created in each hour.
[0045] Increasing the pulse frequency increased the number of pores generated in each unit time. Because the laser strength is the highest on the top surface of the matrix and the lowest on the bottom of the matrix, an inverted cone-like structure of each cylindrical pore will be created during the laser ablation process. One advantage of using this technology is its capability to precisely relocate to its previous position; therefore, the ablation process can be repeated multiple times to ensure that each pore in the matrix is open. To prepare tubular matrix with different pore sizes and densities (optimization of the matrix), the operation parameters will be modulated in the following ranges: laser aperture 20 - 45 , laser pulse energy 15 - 35 , laser speed 5 - 100 , and laser pulse frequency 10-65 Hz. The new technology has been developed and the biomimetic synthetic matrix has been prepared and optimized.
[0046] In the process, when the laser strength is highest on the top of the matrix, the pore size is larger on the top surface of the matrix relative to the bottom surface and progressively decreases in size along the depth of the matrix. However, it is desirable in certain situations to create a matrix having a pore size that is smaller on the top surface and larger on the bottom surface. In such situations, the bottom surface of the matrix is contacted with a glass substrate prior to exposing the top surface of the matrix to the laser. Contacting the bottom surface of the matrix with a glass substrate causes more heat to be generated on the bottom of the matrix than on the top surface, which in turn generates larger pores on the bottom of the matrix relative to the top surface of the matrix. Thus, using the processes of the claimed invention, it is possible to create a matrix having a continuously variable pore size along the depth of the matrix.
[0047] While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure. | The present invention relates to a biomimetic matrix for providing structural support and scaffolding that allows for regeneration of dentin, pulp, and periodontal tissues. A method of making the biomimetic matrix provides the ability to select both a size of a pore or tubule formed in the biomimetic matrix and a density of pores or tubules disposed throughout the biomimetic matrix. The present invention discloses an approach of successful tubular dentin regeneration both in vitro and in vivo using the biomimetic matrix. | 3 |
This is a division of application Ser. No. 797,713 filed May 17, 1977, now U.S. Pat. No. 4,127,608.
SUMMARY OF INVENTION
In accordance with this invention, there is provided a method for synthesizing compounds of the formula: ##STR1## wherein R is ##STR2## or --CH 2 --(CH 2 ) n --OR 1 ;
n is an integer of from 0 to 1 and R 1 taken together with its attached oxygen atom forms an ester group removable by hydrolysis or an ether group removable by hydrogenolysis or acid catalyzed cleavage
by condensing a compound of the formula ##STR3## with a compound of the formula: ##STR4##
where R is as above.
When R is ##STR5## the compound of formula I is converted to Vitamin E which has the following formula: ##STR6##
On the other hand, when R is --CH 2 --(CH 2 ) n --OR 1 , the compound of formula I can be converted to produce the compound of the formula: ##STR7##
wherein n is as above
which are all well-known intermediates in the synthesis of Vitamin E [see Mayer et al. Helv. Chem. Acta., 46, 650 (1963) and Scott et al., Helv. Chem Acta, 59, 290 (1976)].
DETAILED DESCRIPTION
As used throughout this application, the term "lower alkyl" comprehends both straight and branched chain saturated hydrocarbon groups containing from 1 to 7 carbon atoms such as methyl, ethyl, propyl, isopropyl, etc. As used throughout this application, the term "halogen" includes all four halogens, such as bromine, chlorine, fluorine and iodine. The term "alkali metal" includes sodium, potassium, lithium, etc.
The term "lower alkoxy" as used throughout the specification denotes lower alkoxy groups containing from 1 to 7 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, etc. The term "lower alkanoyl" as used throughout this specification denotes lower alkanoyl groups containing from 2 to 6 carbon atoms such as acetyl or propionyl. As used herein the term "aryl" designates mononuclear aromatic hydrocarbon groups such as phenyl, which can be unsubstituted or substituted in one or more positions with a lower alkylenedioxy, a halogen, a nitro, a lower alkyl or a lower alkoxy substituent, and a polynuclear aryl groups such as naphthyl, anthryl, phenanthryl, azulyl, etc., which can be unsubstituted or substituted with one or more of the aforementioned groups. The preferred aryl groups are the unsubstituted mononuclear aryl groups, particularly phenyl. The term "aryl lower alkyl" comprehends groups wherein aryl and lower alkyl are as defined above, particularly benzyl. The term "aroic acid" comprehends acids wherein the aryl group is defined as above. The preferred aroic acid is benzoic acid.
As used herein the term "alcohol protecting group" comprehends any conventional organic alcohol protecting group such as those listed in McOmie, "Protective Groups in Organic Chemistry", Chapter 3, Plenum Press, New York, 1973; Harrison and Harrison, "Compendium of Organic Synthetic Methods", Vols. I, II, Sect. 45-A, John Wiley and Sons, New York, 1971 and 1974; "Annual Reports in Organic Synthesis", 1970-1975, Sect. V-A, Academic Press, New York, 1971-1976.
Exemplary protecting groups are esters removable by hydrolysis such as acetates, benzoates, trihaloacetates, methanesulfonates and p-toluenesulfonates; ethers removable by hydrolysis such as tetrahydropyranyl, t-butyl, 2-methoxymethyl, 2-ethoxyethyl; trialkylsilyl ethers such as trimethylsilyl and t-butyldimethylsilyl; ethers removable by hydrogenolysis such as benzyl, alkyl or benzhydryl ethers.
The preferred ethers which are removed by acid hydrolysis are tetrahydropyranyl, 2-ethoxyethyl and t-butyl.
The preferred ethers which are removed by hydrogenolysis are benzyl and substituted benzyl.
The preferred esters which are removed by acid or base hydrolysis are acetates, formates and benzoates.
In accordance with this invention, the compound of formula III is prepared by reacting a compound of the formula ##STR8##
wherein R is as above with a conventional methylenation agent such as dimethylsulfonium methylide or dimethyloxosulfonium methylide as disclosed by Corey et al. in J. Amer. Chem. Soc., 84, 3782 (1962); Ibid., 87,1353 (1965), Ibid., 84, 867 (1962).
In accordance with a preferred embodiment of this invention, the sulfonium methylide is formed by treating trimethylsulfonium chloride with sodamide in liquid ammonia. After formation of dimethylsulfonium methylide, the compound of formula X is added to the same reaction mixture in which the dimethylsulfonium methylide was formed. Temperatures are utilized in this reaction to maintain the ammonia in a liquid state during the reaction.
Alternatively, the compound of formula X may be converted to the compound of formula III by a two-step procedure in which the compound of formula X is first treated with a methylenetriarylphosphorane such as methylenetriphenylphosphorane to form an olefin of the formula: ##STR9##
wherein R is as above.
The methylenetriphenylphosphorane is generated by any conventional means for example as disclosed by Wittig et al. in Org. Syn., 40, 66 (1960). For example, it is generated by treatment of a methyltriphenylphosphonium halide, e.g. methyltriphenylphosphonium bromide with a strong base, such as n-butyllithium in an inert organic solvent such as tetrahydrofuran. The methylenetriphenylphosphorane is then reacted with the compound of formula X in the same reaction mixture in which the methylenetriphenylphosphorane was formed.
The compound of formula XI is converted to the compound of formula III by oxidation with a peracid. Any conventional peracid may be used such as peracetic acid, m-chloroperbenzoic acid, monoperphthalic acid and percamphoric acid. This reaction is carried out by adding a solution of the peracid to a solution of the compound of formula XI in an inert organic solvent such as dichloromethane or acetic acid at a temperature of -10° C. to room temperature.
When R, in the compound of formula XI is --CH 2 --(CH 2 ) n --OR 1 and R 1 is hydrogen, i.e., a compound of the formula: ##STR10## it may be converted to the compound of the formula III where R is --CH 2 --(CH 2 ) n --OR 1 and R 1 is hydrogen, i.e. a compound of the formula: ##STR11## by the above peracid reagents or by epoxidation using an organic hydroperoxide in the presence of vanadium or molybdenum catalyst according to the procedure of Sharpless et al., J. Amer. Chem. Soc., 95, 6136 (1973); Ibid., 96, 5354 (1974).
In order to form the compound of formula I, the dianion of the compound of formula II which has the formula: ##STR12##
wherein M 1 + and M 2 + are alkali metal ions is condensed with the compound of formula III. This reaction is carried out in a anhydrous aprotric solvent. Any conventional anhydrous aprotic solvent can be utilized to carry out this condensation. Among the preferred aprotic solvents are included diethyl ether, tetrahydrofuran, hexamethylphosphoramide, etc. This condensation is carried out at a temperature of from -10° C. to 50° C.
The dianion of formula II-A is prepared from the compound of formula II via the monoanion of the formula ##STR13##
wherein M 1 is as above.
The compound of formula II is converted to the monoanion of formula II-B by treating at a temperature of -70° C. to 20° C. the compound of formula II with a base to form the monoanion of formula II-B. In forming the monoanion, it is preferred to react the compound of formula II with one equivalent of the base per equivalent of the compound of formula II. The preferred bases are sodium hydride, sodamide, lithium dialkylamides, potassium hydride, alkali metal hydroxides or alkoxides or an alkali metal. The reaction may be carried out in an inert solvent. Among the preferred solvents are alkanols such as ethanol, methanol, etc., water, diethyl ether, tetrahydrofuran, dimethylformamide or hexamethylphosphoramide. If a solvent other than an aprotic solvent is utilized, it must be replaced by an aprotic anhydrous solvent in order to carry out the next step of converting the monanion of formula II-B to the dianion of formula II-A. This non-aprotic solvent can be removed by evaporation to obtain the monoanion, there is added an aprotic anhydrous solvent medium to carry out the conversion of a compound of formula II-B to the dianion of formula II-A.
The conversion of the monoanion of formula II-B to the dianion of formula II-A is carried out by treating the monoanion of formula II-B with a strong base in an anhydrous aprotic solvent at a temperature of from -70° C. to 20° C. Any conventional solvent can be utilized in carrying out this reaction. Among the strong bases which are suitable for carrying out this reaction are included alkyl lithium, alkali metal dialkylamides or sodamide. Among the preferred strong bases are included butyllithium, methyllithium, lithium diisopropylamide. The formation of the dianion of formula II-A is expediently carried out by reacting the monoanion of formula II-B with one equivalent of base per equivalent of monoanion. The dianion of formula II-B can be isolated, if desired, by low temperature evaporation of the solvent. However, since the reaction medium in which the dianion is formed can be utilized to react this dianion in the next step with the compound of formula III to form the compound of formula I, there is no necessity to isolate the dianion of formula II-A.
A preferred method for forming the dianion of the compound of formula III is by utilizing the procedure of Weiler, J. Amer. Chem. Soc., 92, 6702 (1970) through treatment of the compound of formula III with one equivalent of sodium hydride in tetrahydrofuran at 0° C. and then with one equivalent of butyllithium at 0° C. in the same solvent.
The compound of formula I is next converted to a compound of the formula ##STR14##
wherein R is as above and R 10 is lower alkyl.
The compound of formula I is converted to the compound of formula XV by reacting the compound of formula I with a di(lower alkyl) acetone-1,3-dicarboxylate such as dimethyl acetone-1,3-dicarboxylate in the presence of an alkali metal lower alkoxide in a lower alkanol solvent. Any conventional lower alkanol solvent such as methanol, ethanol, isopropanol, etc., can be utilized. Alternatively, the reaction may be carried out with an alkali metal salt of the di(lower alkyl) acetone-1,3-dicarboxylate in an inert organic solvent such as benzene, tetrahydrofuran, diethyl ether, or dimethylformamide. In carrying out these reactions, temperature and pressure are not critical and this reaction can be carried out at room temperature and atmospheric pressure. If desired, higher or lower pressures and/or temperatures can be utilized.
The compound of formula XV is next converted to a compound of the formula ##STR15##
wherein R is as above
by treatment with an aluminum hydride reducing agent. The compound of formula XV is converted to the compound of formula XVI by treating the compound of formula XV with an aluminum hydride reducing agent at a temperature of from 120° C. to 180° C. In carrying out this reaction, any conventional aluminum hydride reducing agent, which does not decompose at temperatures above 120° C., preferably from 120° C. to 180° C., can be utilized to carry out this reaction. Among the preferred aluminum hydride reducing agents are sodium dihydrobis[2-methoxyethoxy]aluminate and di(lower alkyl) aluminum hydrides such as diisobutyl aluminum hydride. In carrying out this reaction, any inert organic solvent can be utilized. Among the preferred inert organic solvents are the inert organic solvents boiling above 120° C. at atmospheric pressure such as diglyme, xylene, etc. If desired, inert organic solvents which are lower boiling can be utilized at temperatures of 120°-180° C., if the reaction is carried out under pressure.
In the next step of this process, the compound of formula XVI is converted to a compound of the formula: ##STR16##
where R is as above
by reacting the compound of formula XVI with an oxidizing agent described hereinafter.
Where R in the compound of formula XV is --CH 2 --(CH 2 ) n --OR 1 , a compound of the formula: ##STR17##
wherein n and R 1 are as above
is formed which is thereafter converted to a compound of the formula: ##STR18##
wherein R 1 and n are as above
by reacting the compound of formula XVI-A with an oxidizing agent as described hereinafter.
The compound of formula XVI-A is converted to the compound of compound XVII-A by oxidation with a nitrosodisulfonate salt of the formula ##STR19##
wherein M is an alkali metal.
Among the preferred nitrosodisulfonate salts are included Fremy's salt. In carrying out this reaction, any of the conditions conventional in oxidizing with Fremy's salt as well as other nitrosodisulfonates can be utilized. Generally, this reaction is carried out in an aqueous medium. In carrying out this oxidation, temperature and pressure are not critical and this reaction can be carried out at room temperature and atmospheric pressure. On the other hand, elevated or reduced temperatures can be utilized.
On the other hand, where R in the compound of formula XVI is, ##STR20## i.e., a compound of the formula ##STR21## There is no reaction between the oxidizing agent of formula XX and the compound of formula ##STR22## is not formed.
In accordance with this invention, we have discovered a new organic-soluble oxidizing agent which will convert the compound of formula XVI-B to the compound of formula XVII-B. this oxidizing agent has the formula ##STR23##
wherein R 11 , R 12 and R 13 are alkyl containing from 1 to 20 carbon atoms and R 14 is alkyl containing 8 to 20 carbon atoms.
The oxidizing agent of formula XXI can also oxidize the compound of formula XVI-A to the compound of formula XVII-A and is generally effective in oxidizing phenols usually oxidized with Fremy's salt, e.g. durophenol.
In the compound of formula XXI, R 11 , R 12 and R 13 can be any straight or branched chain alkyl group containing from 1 to 20 carbon atoms such as methyl, n-octyl, isopropyl, ethyl, n-decyl 2,4,6-trimethyldodecyl, n-octadecyl, etc. Also, R 14 can be any straight or branched chain alkyl group containing from 18 to 20 carbon atoms such as n-decyl, n-octyl, 2,4,6-trimethyldodecyl, n-octadecyl, etc. Among the preferred compounds of formula XXI such as tri(n-octyl)mono methyl ammonium nitrosodisulfonate and tri(n-decyl)mono methylammonium nitrosodisulfonate.
The compound of formula XXI is formed by reacting the compound of formula XX with a quaternary ammonium salt of the formula ##STR24##
wherein R 11 , R 12 , R 13 and R 14 are as above and Y.sup.⊖ is a halide or HSO 4 .sup.⊖ ion.
This reaction is carried out in a two phase system consisting of an aqueous solution or suspension of the salt of formula XX and an inert organic solvent such as toluene, benzene, xylene, etc. In carrying out this reaction, temperature and pressure are not critical and this reaction can be carried out at room temperature or atmospheric pressure. The compound of formula XXI is formed in the organic layer. On the other hand, higher or lower temperatures can be utilized. Generally, this reaction is carried out at a temperature of from 0° C. to 50° C. The salt of formula XXI can be isolated from the reaction medium by separating the aqueous layer and evaporating the organic solvent. However, since the salt of formula XXI can be utilized to oxidize the compound of formula XVI to a compound of formula XVII in the solvent medium, one need not isolate the salt of formula XXI from the reaction medium but may oxidize the compound of formula XVI to the compound of formula XVII directly in the solvent medium.
In addition, the compound of formula XX need not be formed in stoichiometric amount to the phenol of formula XVI-B since the oxidation may be run by adding a catalytic amount of the quaternary ammonium salt of formula XXII to a two-phase water-organic solvent medium containing a stoichiometric amount of the compound of the formula XX.
In carrying out this oxidation reaction, temperature and pressure are not critical and this reaction can be carried out at room temperature and atmospheric pressure. On the other hand, elevated or reduced temperatures can be utilized. Generally, it is preferred to utilize temperatures of from 0° C. to 50° C.
The compound of formula XVII-B can be converted to Vitamin E by reaction with sulfuric acid in methanol such as described by Mayer et al. Helv. Chim. Acta, 50, 1168 (1967) or reductive cyclization with butyl mercaptan such as disclosed by Oxman and Cohen, Biochem. Biophys.Acta, 173, 412 (1966). In the same manner, the compound of formula XVII-A can be converted to a compound of the formula: ##STR25##
wherein R 1 is as above.
Where R 1 forms an ester, any conventional method of ester hydrolysis can be utilized to convert the compound of formula V-A to a compound of formula V. Wherein R 1 forms an ether group removable by hydrogenolysis, any conventional method of hydrogenolysis can be utilized to affect this conversion. On the other hand, where R 1 forms an ether group removable by acid catalyzed cleavage, any conventional method of acid catalyzed cleavage can be utilized to affect this conversion.
The following examples are illustrative but not limitative of the invention. In the examples, all temperatures are in degrees centigrade. The ether utilized in the following examples is diethyl ether.
EXAMPLE 1
1,2-Epoxy-2,6,10,14-tetramethylpentadecane
To a solution of sodamide in 120 ml of liquid ammonia under reflux (prepared from 9.12 g (0.40 mol) of sodium) was added a solution of 80.0 g (0.29 mol) of hexahydrofarnesylacetone in 300 ml of diethyl ether while maintaining a temperature of -33° with external cooling in a Dry Ice-isopropanol bath. After 15 min 45 g (0.37 mol) of trimethylsulfonium chloride was added rapidly. After the addition, the Dry Ice condenser was removed and the ammonia was allowed to evaporate while stirring overnight. The mixture was then cooled in an ice bath and 16.2 g of ammonium chloride was added. The mixture was stirred 30 min at room temperature, was filtered through Celite and washed twice with water. The ether solution was washed with brine, was dried over anhydrous magnesium sulfate and was concentrated on a rotary evaporator to give 82.18 g of crude epoxide as an oil. The crude oil (80.93 g) was distilled rapidly through a short-path distillation head to give 75.5 g of 1,2-epoxy-2,6,10,14-tetramethylpentadecane, bp 0.08 mmHg=108°-110°.
EXAMPLE 2
7-Hydroxy-7,11,15,19-tetramethyleicosane-2,4-dione
To a suspension of sodium hydride (30.0 g of 57% by weight dispersion, 0.72 mol, washed free of oil) in tetrahydrofuran (500 ml) at 0° was added dropwise over 30 min a solution of 2,4-pentanedione (71 g, 0.71 mol) in 150 ml of tetrahydrofuran to form the monosodium salt of 2,4-pentanedione in tetrahydrofuran. After stirring the tetrahydrofuran solution containing the salt for 20 min. at 0°, butyllithium (260 ml of 2.5 M solution in hexane, 0.65 mol) was added over 30 min at 0°-5° to form the sodiolithium salt of 2,4-pentanedione and the solution containing this sodiolithium salt was stirred 20 min. at 0°-5°. The 1,2-epoxy-2,6,10,14-tetramethylpentadecane (40 g, 0.142 mol) in 50 ml of tetrahydrofuran was then added in one portion and the solution was stirred for 17.5 hr. at room temperature. The solution was cooled to 0° and was poured into a vigorously stirred mixture of ice (2 kg) and conc. aqueous hydrochloric acid (114 ml). Then saturated aqueous ammonium chloride solution (100 ml) was added and the mixture was extracted with diethyl ether (3×750 ml). The combined extracts were washed with water and brine and were dried over anhydrous magnesium sulfate and concentrated on a rotary evaporator and then at 30°-35°/0.3 mmHg for 2.5 hr to give 73.50 g of crude hydroxydiketone 7-hydroxy-7,11,15,19-tetramethyleicosane-2,4-dione as an oil. An 0.360 g sample was purified by preparative thin layer chromatograph to give 0.20 g of 7-hydroxy-7,11,15,19-tetramethyleicosane-2,4-dione as a light yellow oil.
EXAMPLE 3
Dimethyl 2-hydroxy-4-methyl-6-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-benzene-1,3-dicarboxylate
To a solution of 7-hydroxy-7,11,15,19-tetramethyleicosane-2,4-dione (72.5 g) and dimethyl acetonedicarboxylate (29.6 g) in methanol (190 ml) at 0° was added a solution of sodium methoxide in methanol (from 2.44 g of sodium and 90 ml of methanol). The solution was stirred at room temperature for 44 hr and was concentrated on a rotary evaporator to remove approx. 100 ml of methanol. The residual solution was poured onto ice (500 g) and 20% (v/v) aqueous hydrochloric acid (45 ml). The mixture was extracted with ether (3×300 ml) and the combined extracts were washed with brine and dried over anhydrous sodium sulfate and were concentrated on a rotary evaporator to give 91.65 g of crude dimethyl 2-hydroxy-5-methyl-6-(3-hydroxy-3,7,11,15-tetramethyl-hexadecanyl)-benzene-1,3-dicarboxylate as an orange oil. A 90.2 g portion of the oil was dissolved in ether (400 ml) and was washed with 20% by weight aqueous potassium carbonate (to remove the unreacted dimethyl acetonedicarboxylate), brine and was dried over anhydrous sodium sulfate. The solution was concentrated on a rotary evaporator to give 83.13 g of partially purified diester dimethyl 2-hydroxy-4-methyl-6-(3-hydroxy-3,7,11,15-tetramethyl-hexadecanyl)-benzene-1,3-dicarboxylate. The total material was chromatographed on 2.45 kg of silica gel eluting with 20-30% by volume ether in hexane to give 30.83 g of dimethyl 2-hydroxy-4-methyl-6-(3-hydroxy-3,7,11,15-tetramethyl-hexadecanyl)-benzene-1,3-dicarboxylate as a colorless oil.
EXAMPLE 4
2,3,6-Trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol
To a solution of the dimethyl 2-hydroxy-4-methyl-6-(3-hydroxy-3,7,11,15-tetramethyl-hexadecanyl)-benzene-1,3-dicarboxylate (5.17 g) in xylene (25 ml) at 10° was added sodium dihydrobis(2-methoxyethoxy) aluminate (20 ml of a 70% by weight solution in benzene) over 20 min with occasional cooling to keep the temperature at 10°. After 10 min the solution was heated to reflux for 1.5 hr, cooled to 10° and was poured cautiously into cold 20% by weight aqueous sulfuric acid (200 ml). The mixture was extracted with ether (3×100 ml) and the combined extracts were washed with aqueous sodium bicarbonate and brine and dried (Na 2 SO 4 ) and concentrated on a rotary evaporator to give 4.29 g of crude 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol as a light yellow oil. Chromatography on silica gel eluting with ether in petroleum ether gave 3.19 g of pure 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol.
EXAMPLE 5
To a slurry of Fremy's salt (di-potassium nitrosodisulfonate) in sodium carbonate (1.6 g) was added 10 ml of 15% sodium carbonate solution and a solution of 0.29 g (0.72 mmol) of tri(caprylyl)monomethylammonium chloride I in 4 ml of benzene. The phenol, i.e. 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethyl hexadecanyl)-phenol (0.3 g, 0.69 mmol) in 8 ml of benzene was added and the mixture was stirred vigorously for 2.5 hr. The mixture was poured into 5 ml of water and was extracted with 10 ml of petroleum ether. The organic phase was washed with water (2×10 ml) and the cloudy mixture was dried (Na 2 SO 4 ) and concentrated on a rotary evaporator. The residual crude quinone was chromatographed on 7.0 g silica gel eluting with ether-petroleum ether to give 0.321 g tocopheroquinone.
EXAMPLE 6
A solution of Fremy's salt was prepared by dissolving 8.45 g of the sodium carbonate slurry in 52 ml of 15% sodium carbonate followed by adding 0.5 g solid sodium carbonate. The concentration of the solution was determined to be 0.175 M by measuring the absorption spectrum at 440 nm where ε=14.5. The solution of the Fremy's salt, the phenol, i.e. 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol, tri (capryl)monomethylammonium chloride, and benzene (2 ml) were added in the amounts given in the table below with the reaction being monitored by thin layer chromatography to completion. This reaction gave tocopheroquinone.
__________________________________________________________________________ ON(SO.sub.3 K).sub.2, phenol, (C.sub.10 H.sub.21).sub.3 NCH.sub.3 Cl,Expt. ml (mmol) g (mmol) g (mmol) time to completion__________________________________________________________________________1 3.07 (0.537) 0.1 (0.23) 0.02 (0.047) 5 hr.2 3.07 (0.537) 0.1 (0.23) 0.09 (0.23) 2-3 hr.3 3.07 (0.537) 0.1 (0.23) 0.18 (0.47) 20 min.4. 3.07 (0.537) 0.1 (0.23) 0.37 (0.92) 20 min.__________________________________________________________________________
EXAMPLE 7
Ten ml of a deep purple 0.154 M solution of Fremy's salt in 5% (w/v) aqueous sodium carbonate was extracted with a solution prepared from 1.25 g of tri(n-decyl)monomethylammonium chloride and 10.0 ml of benzene. The purple color rapidly was transferred to the benzene layer which was separated and dried over anhydrous potassium carbonate to give a benzene solution of bis[tri(n-decyl)monomethylammonium]nitrosodisulfonate. The solution displayed an absorption maximum in the visible spectrum at λ max =552-8 nm (ε˜15).
When chloroform was used in the extraction in place of benzene, the bis[(tri(n-decyl)monoethylammonium]nitrosodisulfonate was obtained in the chloroform layer and after separation and drying displayed infrared absorptions at λ max =1270 and 1026 cm -1 .
EXAMPLE 8
The benzene solution of bis[tri(n-decyl)monomethylammonium] nitrosodisulfonate prepared in Example 7 was used to oxidize 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexa-decanyl)-phenol to tocopheroquinone. | A synthesis of Vitamin E has the condensation of 2,4-pentanediene and 1,2-epoxy-2,6,10,14-tetramethylpentadecane including intermediates in this synthesis which uses base catalyzed condensations of aliphatic compounds to construct the Vitamin E molecule from aliphatic precursors. | 2 |
RELATED APPLICATIONS
The present application is a divisional of application Ser. No. 12/383,714, filed on Mar. 26, 2009, for Red Grape Dry Composition and Health Tea. The Examiner restricted the claims submitted in an amendment filed Dec. 19, 2011, directed to a method for making the product, and only examined the claim drawn to a composition.
BACKGROUND
1. Field of Invention
Red grape dry composition and health drink containing powerful antioxidants including resveratrol, for human consumption, and for skin topical application, the production thereof and use of the same.
2. Prior Art
This invention relates to a human food product that, due to its nutrient characteristics, contains many health benefits. It is suitable for human consumption in the form of a tea-like beverage as part of a normal daily diet, or in other forms as a food supplement. The invention is prepared by means of a unique, simplified method using stalks, skins, and seeds of red grape berries, which, combined together, naturally bear powerful anti-inflammatory properties when the ingredients are subjected to natural methods of fermentation and other natural processing.
Grape seeds and skins have been long under scrutiny by the scientific community for their strong antioxidant characteristics. Recent advances in medicine, biology, and other sciences have brought new light in a quest for longer, healthier human life span. One of the most important discoveries in the last ten years was a set of genes, called sirtuin, which is believed to play a critical role in regulating the lifespan. Chemicals that affect sirtuin activity have been found in plants, and one specifically, resveratrol, is viewed as notably powerful in the process of activating health-promoting genes.
Resveratrol is a phytoalexin produced naturally by several plants, including grapes (primarily in the seed and skins), apparently due to its anti-fungal reaction. Plants, e.g. blueberries, bilberries, peanuts and others, generate resveratrol, and it is, also present (in a wide range, 0.4-40 mg/L) in grape wines, especially reds. Grape pomace/marc (byproducts of winemaking), grapes juices, and wines are all used as a source for resveratrol extraction.
Resveratrol anti-inflammatory properties are utilized by pharmaceutical industries in the U.S. and overseas in making drugs and food supplements. Gokaraju et al. (U.S. Pat. No. 7,026,518, 2006) stated that antioxidant and superoxide scavenging properties of resveratrol have been scientifically established. Efforts are now being made to synthesize structural analogs of resveratrol for evaluation of their relative antioxidant potentials.
Cambridge based bio-pharmaceutical company, Sirtris, Inc. (NASDAQ: SIRT) is searching to develop a proprietary molecule drug to treat diseases associated with aging, including metabolic diseases such as Type 2 Diabetes. In January 2008, the company released results from recent clinical trials that found patients with diabetes who took the drug (SRT-501) showed improvement. The treatment is a concentrated form of resveratrol, a substance extracted from red wine. Sirtris hopes to bring its drug to market in 2012. (The Boston Globe, Jan. 10, 2008).
Furthermore, grape seeds and skins have a high concentration of other phenolic components that are also recognized for positive effects on human health: tannin (studies by Feries et al. (U.S. Pat. No. 6,479,081, 2002)), catechin, resveratrol, and quercetin (hereinafter “CRQ”), as well as vitamins and minerals. A number of U.S. patents were issued to inventions which discovered either new health-beneficial compositions, including grape seeds/skin processed derivatives, and/or offered innovative combinations and/or methods of their intaking Schakel et al. (U.S. Pat. No. 7,273,607, 2007) studied grape seed extract and recommended its usage in combination with other herbs and essential oils. Schakel's formula, including grape seed extracts, claimed to slow, stop, or reverse the growth of cancerous cells. Hersh, et al. (U.S. Pat. No. 6,470,894, 2002) suggested including grape seed extract into a composition to neutralize tobacco free radicals. Hersh and others revealed grape seeds' ability to reduce free radical damage to the oro-pharyngeal cavity, respiratory tract, and lungs resulting from tobacco smoke. Moreover, Wild, et al., (U.S. Pat. No. 7,087,259, 2006) demonstrated that the presence of oligomeric procyanidins in grape seed extracts makes them very efficient free-radical scavengers due to their hypotensive and antiarteriosclerotic properties.
Howard et al. (U.S. Pat. No. 6,086,910, 2000 & U.S. Pat. No. 6,642,277, 2003) conducted comprehensive studies with plant-derived polyphenols for human health benefits. The inventors showed, including through experiments on volunteers, positive therapeutic effect of their proprietary 25% polyphenol concentrate in critical human health areas, e.g. preventing or treating coronary heart disease; and inhibition of oxidation of plasma LDL and/or platelet aggregation. Howard et al. used grape wine, pomace (substance comprising grape marc and juice prior to pressure-separating) among their sources for preparing polyphenol powder. The inventors, furthermore, used the following methods to extract resveratrol: a) vacuum distillation at 75-80 degrees C., and b) nitrogen drying.
Many, if not all, of the essential characteristics of grape seeds and skins described in the aforementioned inventions, such as the ability to neutralize inflammatory processes, to slow the growth of cancerous cells, and others, should safely exist in the new composition of the substance of the present invention, i.e. dry grape berry stalks, skins and seeds and health drink made therefrom. The present invention greatly differs from findings and products currently available in scientific and practical fields.
Most patents reviewed target novel compositions of prescribed drugs for hospital patients, while the prime objective of the present invention is a natural plant composition designed for prophylactic and prevention treatment. In the food supplements field, reviewed patents (e.g. Wild et al. U.S. Pat. No. 7,087,259) cover mostly grape seed/skin extracts without the inclusion of the grape berry stalks, which is an important distinction of this invention. None of the observed patents or products available on the market matches the uniqueness of the present invention either in terms of the combination of grape plant parts, or in terms of originality of preparation method involving natural fermentation. For instance, Howard et al., by using, as a source, commercially obtained wine or pomace (that were other makers' products), subjected themselves to a greater chance of uncertainty. Advantageously, findings of the present invention benefit from having raw grape plants, Concord Grapes from the Finger Lakes region of the U.S., as its initial source. Thus, while viewing the wine as a source for polyphenols and resveratrol, an intriguing connection is found between the wine making method (whether or not it was fermented and mixed with skins, seeds and stems/stalks) and the amount of resveratrol found in the final substance. For instance, Spanish wines tend to be resveratrol-richer due to the fact that local wine-makers, historically, preferred to ferment crushed grapes mixed with skins, seeds, and stalks, for a relatively longer time.
Also, it looks like a similar method was used by Stone Age people, 8,000 years ago, in Shulayeri village in Georgia (Caucasian Mountain) where the world's oldest wine was recently found. Hence, with regard to fermenting, this invention employed a method similar to ancient traditions, i.e. a) three components of a grape plant: grape berry stalks, skins and seeds were used in the mixture for fermentation; and b) an extended fermenting period, up to three weeks, was employed. This technique is based on an existing hypothesis that biological and chemical reactions during pomace/marc fermentation provide a favorable environment for preserving, or even enriching phenolic antioxidants, including resveratrol, in the substance. Furthermore, words of caution should be expressed with regard to techniques used by researchers to extract antioxidants. Specifically, Gourdin, et al. (U.S. Pat. No. 7,306,815, 2007) studied the enrichment methods of phenolic compounds and concluded that a hot extraction temperature can cause degradation of the proanthocyanidins. In addition, it was found that the ultrafiltration removes some of the low molecular weight polyphenolic material from the final product.
A Napa Valley (CA) based company sells assorted “Antioxidant Grape Seed Spa Teas” that are worth review as remotely comparable to the composition of this invention. The sample we tasted had the following ingredients: wine grape seeds, rose petals, chamomile, orange peel, stevia and natural fruit oils. Whether there were antioxidants, and if so their levels, was not indicated on the label. The findings of physical examination showed that the grape seed content in the composition of the 2 g tea bag was about 10-15%. This means that the composition would contain a proportional amount of phenolic antioxidants, i.e. 10-15% per 2 g tea bag, given that Napa Valley used CRQ potent grapes. Neither grape skins nor stalks have been found in “Grape Seed Spa Tea.” Thus, many manufacturers choose to present and advertise their product using just general terminology. In some cases, they would refer to resveratrol or other antioxidant contents in an original fruit or plant source, not in a final product. Advantageously, the present inventive composition is to consist of 80-100% of red grape stalks, skins, and seeds which contain a potent group of phenolic antioxidants (HPLC) that are proven to be present in the final product as well as in its original natural source.
Besides resveratrol, catechin, quercetin, and tannin are present in the composition of the present invention. These substances have also been found to have positive effects on the human immune system in different trials. Weyant et al. studied the implications of catechin on a cancerous mouse to conclude that catechin inhibited intestinal tumor formation and “suppressed focal adhesion kinase activation.” (Cancer Research (ISSN 0008-5472), 61, 118-125, Jan. 1, 2001, by the American Association for Cancer Research, Inc. (AACR)). J. Mark Davis (Professor and Director of Exercise Biochemical Laboratory, University of South Carolina) named quercetin a powerful antioxidant shown to reduce the risk of flu in laboratory animals. Recent studies have also shown the capacity of tannins to suppress production of the peptides responsible for hardening arteries, as well as other potential antiviral, antibacterial and antiparasitic effects. In the past few years, tannins have also been studied for their potential effects against cancer through different mechanisms.
Furthermore, phenol products, especially grape seed oil, are known to be able to prevent ultraviolet light-induced damage to human hair and skin and otherwise rejuvenate facial and body skin. The cosmetics industry uses these properties in manufacturing sunscreens, body scrub cleansing, hair dyes and others. According to a London-based market research firm “Mintel International Group, Ltd,” grapes are widely used in the cosmetics industry because of their “anti-aging” properties. (“Grapes boast high potential in anti-aging market” by Guy Monatgue-Jones, Aug. 2, 2008, available at www.cosmeticsdesign.com). One of many facial moisturizes available on the market, “Merlot. Grape Seed Moisturizer” by Merlot, a US company, was examined by the inventor of the present invention. As per the trade label, the main ingredient was ‘grape seed polyphenols.” No grape skins or stalk derivatives were said to be present in the product. Numerous other cosmetic products and related publications were reviewed in order to determine whether any of them offer, recommend or refer to the usage of the ingredient complex similar to those suggested by the present invention. Nothing was found resembling the uniqueness of the present invention composition and the method of its preparation.
SUMMARY OF THE INVENTION
The present invention discloses a unique antioxidant drink and method of its preparation. The ultimate goal of this invention is to provide health-minded people with new natural products, namely, red grape dry composition, health tea or drink, and derivative human skin rejuvenation materials, that <can be inexpensively made by small and medium size vineries and even by individual entrepreneurs at properly equipped home kitchens.> The philosophical basis of the invention lies in following natural methods of processing the grapes: crushing, fermenting, drying, boiling, and steeping, and completely excluding the usage of any catalysts, chemicals or artificial additives.
The socioeconomic importance of the current invention emerges from the fact that the source, the Concord Grape ( Vitis labrusca ), is a native plant to the Eastern United States and is naturally growing in abundance in the Continental climate of the Northern part of New York. This variety of grape is not popular among winemakers due to the fruity aroma of the berry and limited sweetness that contributes to an overall “flat” body of wines. At the same time, due apparently to the fact that this plant was exposed to harsh ecological challenges, it embodies botanical survival characteristics which consequently transfer to humans strong anti-inflammatory capacities. Potent polyphenolic properties of Concord grapes have not yet been fully studied. Obviously, this grape variety was underappreciated not only by winemakers but also by resveratrol-researchers who, often, name Malbec, Petite Sirah, St. Laurent, Pinot Noir and other exotic variety among resveratrol-richest grapes (Ref. F. Breton, “Polyphenols in Red Wine”). The same author points out that “vine grapes grown in cooler climates have higher resveratrol levels than those from warmer climates.”
With the overall economy struggling in recent years, the grape growing and wine industries of the New York region have been experiencing great challenges. Hence our new product made by a noncapital intensive method from the source of the wine industry byproduct can well contribute into new economic development model pursued by the regional governments.
One of the preferred embodiments, grape health tea or beverage, is pleasantly drinkable in a form of a hot or cold herbal tea with a woody aroma, or mixed with a physiologically acceptable food items. Furthermore, the invention importantly discovers a possibility of achieving higher HPLC (polyphenolic antioxidants) concentration by repeating established processing procedures with a greater amount of source material per fixed or smaller volume of water.
Moreover importantly, the preferred embodiment demonstrated anti-inflammatory potency in assisting in the speedy recovery of volunteers suffering from Influenza. In another case, treating individuals with the grape beverage led to considerable lowering of their blood glucose levels. Healthy adults would pleasantly ingest such grape beverage as a food item similar to herbal tea, while people suffering from different medical conditions would be able to take such drink as a supplement to prescribed medications to improve their body's overall resistance to disease.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following describes the preferred embodiments of the present invention, which should not be viewed as a limitation to the whole invention. It should be understood that if further details, specifics, or nuances are to be developed within the frame of the present invention concept, those too will be considered integral parts to the present invention.
(a) Embodiment: Red Grape Dry Composition and the Method of its Preparation.
To prepare the red grape dry composition, Concord grapes were used, which were conveniently purchased in a Finger Lake region vineyard (New York State, USA).
The grape berries were crushed, mixed with berry stems and stalks, and placed in a stainless steel vat for fermenting. Some seeds were intentionally crushed, but not more than 7-10%, whereas the rest were left to ferment in their entirety. The content consisting of a liquid phase (juice or mush) and solid phase (skins or cuticles of the berries, berry stalks/stems, seeds or pomace/marc) was allowed for primary natural fermentation for a period of 8 (eight) days. During this time, ambient yeasts naturally present on the grapes and stems catalyzed the process.
Contrary to prior art inventors, no acidity adjusting chemicals (like sodium hydroxide or potassium metabisulfite from commercial winemaking) were used. Within the first 24 hours of fermentation, lighter parcels formed a “cap” which was punched down twice a day, and at the same time the whole content was thoroughly mixed. This segment of fermentation was conducted at room temperature, 72° F. At the end of eighth day, when active bubbling slowed down, the juice was separated from the pomace/marc by pressing. The solids, consisting of skins, berry stalks/stems, and seeds, and with a limited amount of juice, were left for another 7 (seven) day secondary fermentation. Thorough stirring was performed twice a day. Secondary fermentation was conducted at a lower temperature than primary fermentation, namely 60° F. On the 16 th (sixteenth) day since the commencement of the initial fermentation process, the pomace/marc, i.e. skins, seeds, berry stalks and some stems, still high in moisture, was further pressed to eliminate residual watery content, and was exposed to sun-drying for 6 hours followed up by oven drying. The oven drying was performed at 180° F. for about 10 hours to achieve a water activity at 0.515 (Aw).
((The resulting dry substance constituted the preferred embodiment of the present invention—a red grape dry composition)). The dry composition was sorted out manually to remove larger stems, and was, consequently, automatically ground into a consistent mass of pieces sized +/−⅛ inch. Grinding into a finer powder is also possible to meet specific objectives of the subject task.
The dry composition can be conveniently packed into a regular 3.20 g tea bag. Weight proportions of three components of the dry composition as allocated in the tea bag are shown in Table 1 below.
TABLE 1
Component
Weight
% (in 3.20 g. bag)
1. Berry stalks/stems
0.20 g
6.25
2. Skins
1.00 g
31.25
3. Seeds
2.00 g
62.50
Administration of Red Grape Dry Composition.
In one of the applications, the Red Grape Dry Composition may be used for human skin rejuvenation baths. Loose dry parcels, in the volume equal to approximately 1 cup, is placed into a muslin bag, or any bag made from porous cloth like cotton gauze or any other bag of loose weave fabric. The bag is either hung on the faucet with hot running water, or the herbs are simmered prior to arranging the bath in 4 cups of boiling water pouring the infusion into your water as/when ready. The color of the water becomes rosy. The duration of the bath should not exceed 15-20 minutes, with water temperature close or slightly higher that that of the human body. The cotton gauze bag can be used for skin scrubbing and massaging. Antibacterial rejuvenating properties of the red grapes affect the skin by anti-oxidizing skin cells, tightening and toning up the skin fabric.
(b) Embodiment: Red Grape Health Tea or Drink and the Method of its Preparation.
A total of 80 g of the dry composition was placed in 1 L of filtered hot water just before its boiling point. As the water reached the boiling point, the substance was stirred and kept simmering for 2 minutes. The contents were then steeped for 7-10 minutes, and, afterwards, filtrated into a clean stainless steel container to become the initial liquid base (hereinafter called “Round I Substance”—RI) for further processing. After boiling and filtration out of 1 L, 0.875 L remained. This RI constituted a base for consequential rounds of processing. Another portion of the dry composition of 80 g was placed in and mixed with RI (0.875 L). Then boiling, simmering activities as with RI was performed. The resulting liquid substance, Round II Substance (hereinafter referred as RII), was more concentrated in the volume of 0.698 L. Obviously, RII was heavier with a darker ruby color and a stronger lemon taste. This should indicate strong presence of Concord grape plant acids, mainly tartaric. The RII acidity was measured by Cornell Laboratory to be pH 3.79. Further, RII phenolic antioxidants were measured to show HPLC presence as follows: catechin 12 mg/L, tannin 264 mg/L, resveratrol (cis+trans) 0.8 mg/L, quercetin glycosides 23 mg/L, quercetin 4 mg/L, total antioxidants 11 mmol/L (ETS Laboratory Report #324068 of 01.18.2008). Additionally, RII content was analyzed in accordance with U.S. FDA food standard requirements. The results revealed low calories (10 per 240 g serving), and the presence of Vitamin C (10% DV) and Calcium (2% DV).
Further, Round III Substance (RIII) was prepared by placing 80 g of dry composition into RII 0.698 L, and by following the sequence of steps described for RI. At the end of the test, the liquid volume was 0.463 L. The resulting RIII HPLC properties were notably superior to those of RI and RII: catechin 63 mg/L, tannin 454 mg/L, resveratrol (cis+trans) less than 1.0. mg/L, quercetin glycosides 20 mg/L, quercetin 4 mg/L, total antioxidants 20.6 mmol/L (ETS Laboratory Report #379509 of 02.03.2009). For the purpose of this embodiment, a limit of three rounds of processing was set. Interpretation of the RII and RIII data dynamics reveals a tendency towards greater catechin (+80%) and tannin (+41%) presence in RIII, while resveratrol, glycosides and quercetin remained almost unchanged. The HPLC dynamic in RII and RIII is demonstrated in Table 2.
TABLE 2
HPLC Antioxidant
RII
RIII
% (change)
1.
Catechin
12
mg/L
63
mg/L
+80
2.
Tannin
264
mg/L
454
mg/L
+/−
3.
Resveratrol (cis + trans)
0.8
mg/L
1.0
mg/L
+/−
4.
Quercetin glycosides
23
mg/L
20
mg/L
+/−
5.
Quercetin
4
mg/L
4
mg/L
0
Total
11
mmol/L
20.6
mmol/L
+46.6
Administration of Red Grape Health Drink/Tea.
The Red Grape Health drink (the term “tea or drink” coverers either of RI, RII or RIII) is to be taken as a food supplement, hot or cold, in the volume of 150-200 g, two-three times a day, between meals, at least 20 minutes prior to eating.
(a) RII was applied for treating common cold and proved to be effective. RII treatment was performed against severe Influenza on two volunteers: one a 56 year-old female, the other a 57 year-old male (inventor of the present invention). Both users did not receive flu shots at the beginning of the flu season, Fall of 2007. They were infected with a virus under different circumstances and at different times. The method of treating and the results were exactly the same and can be summarized in the following:
On the first day of feeling a cold a person was given 150 g of hot RII five times daily, between meals, at least 20 minutes prior to eating. This treatment method was administrated for a period of six days. Diet habits were modified, firstly, by increasing the intake of vegetables (especially onion and garlic), fresh fruits, buckwheat, oat and fish; secondly, by eliminating meats, fat, milk, cream, sugar, soft drinks, baked goods; and, thirdly, by reducing the overall daily caloric intake to 1500-1800 (as compared to US customary 2000-2500). No Aspirin or prescribed medications or antibiotics were taken during this period. Physical activities were reduced to the extent possible. The body was kept in a warm environment to allow it to rest and to ensure the temperature level needed for incoming antioxidants to work in synergy with the body's own immune system. No sick-days were taken from the work. Apparently, due to tartaric acid content in RII, the users felt a stronger appetite. Both RII users successfully recovered in six days time, with notable improvements in their health status having taken place after only the third day.
(b) RII was applied for treating high levels of cholesterol and blood glucose and proved to be effective. In this test, the inventor of the present invention (male, age 57, herein after referred to as volunteer) was taking RII with a goal to reduce blood cholesterol which had been in the range of 240-270 mg/dL over the period of the last ten years. The following technique was applied:
Before RII treatment commenced, the volunteer was on a normal diet. On the morning of Jan. 15, 2009, on an empty stomach, a blood test (before RII treatment commencement) was taken with the following results: glucose 84 mg/dL, cholesterol total 275 mg/dl, HDL 51 mg/dL, cholesterol/HDL ratio 5.4, LDL (calculated) 203 mg/dL, triglycerides 104 mg/dL. For the next 48 hours, the volunteer had followed strict “RII Diet” whereas no food was allowed, only hot RII in volumes of 200-400 grams, 4 times a day, (January 15, after blood test, 200 g; at lunch time, 400 g; at dinner time, 200 g; the same was repeated on January 16). A total of 1.6 L was taken. On the morning after the end of the treatment, January 17, a second blood test was taken on an empty stomach. Results showed a slight decrease in total cholesterol (from 275 to 271 mg/dl) with notable increase in “good cholesterol” HDL (from 51 to 59 mg/dL); cholesterol/HDL ratio also favorably changed from 5.4 to 4.6, thus moving into “normal health reference range.”
Triglycerides results considerably improved, dropping from 104 to 29 mg/dL, showing a positive change of 72%.
Furthermore, RII demonstrated the ability to reduce[ing] blood glucose, [that] which dropped from 84 to 69 mg/dL, or approximately 18%. Other components of the metabolic panel have not shown any considerable changes.
Noted RII side effects were as follows: (i) during the 48 hour fasting period, the volunteer felt an increased appetite which could not be satisfied due to the test diet restriction; (ii) RII (RII and RIII) was noted to have a tightening affect on gastro-intestinal tract which can cause a longer food digesting periods.
(c) Another application of RII is that it is beneficial as a Facial Mask. Grape Facial Mask is made with a liquid composition: a clean white cloth is soaked in RII or RIII, then applied to the face for 10-15 minutes; the face is then wiped with a clean cloth, and moisturizing cream is applied to soften the skin. The treatment should be repeated twice a day, once in the morning, once at bedtime.
(d) RII or RIII liquid is used to prepare Grape Facial Spray (GFS). GFS is sprayed onto the face, in small portions, two-three times a day. Spray drops should be allowed to remain on the skin for a few seconds, then the face should be wiped up with a clean cloth, and then moisturizing cream should be applied to soften the skin. Concord grape antioxidants and vitamins defuse within skin fabric providing essential support to skin cells' healthy functioning.
Embodiments of the present invention including those related to human skin care are not limited by the preferred ones described above. Many more varieties and methods may exist in application of the disclosed dry and liquid compositions when mixed, combined, complemented, or subsequently used with other natural organic ingredients customary in the food and cosmetic industries. Those ingredients may include, but are not limited to: honey, dairy products, like butter milk, nut, olive, castor, other vegetable oils and others.
Thus, the scope of the embodiment should be determined by the appended claims and their legal equivalents, rather than examples given. The applicant expressly reserves the right to use all of or a portion of the content or claims as a base and/or additional description to broaden detailed support any of or all the claims or any element or component thereof. The applicant further reserves the right to move any portion of the incorporated content of such claim or any component thereof from the claim into the description or vice-versa as necessary to justify or present the subject matter as appropriately, or to obtain any benefit, or to comply with the patent law, rules and regulations of any country or treaty. All claims and content of the present application shall survive during the entire pendency of this application including any subsequent addition, continuation, detailing, division thereof or any reissue or extension thereon. | A method for producing a dry composition from red grapes by natural fermentation that is, once brewed, steeped within hot water, tasteful to ingest as herb tea, and that complementary contains antioxidants, Catechin, Resveratrol, Tannin, Quercetin bearing anti-inflammatory and blood glucose lowering capacities; as well as a human skin rejuvenating natural product derived there from. The method is used to prepare dry composition containing phenolic antioxidants such as catechin, resveratrol, and quercetin, and comprises small parcels made from the grape berry, stalks, skins and seeds of the red grape Vitis labrusca . The method uses the sequential steps of crushing, two successive natural fermentation periods, and drying by utilizing simplified operations. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a scheme capable of alleviating load born by a print server utilized in a printing system while leaving constant usability of the printing system of a client maintainable.
[0003] 2. Related Background Art
[0004] In conventionally known printing systems, such a form utilizing a print server is implemented generally. In addition, in order to stabilize a printing system, it is desired to alleviate the load to be born by a print server. In addition, technology for alleviating process load of a print server is known.
[0005] According to this technology, a printing system has been disclosed and comprises a print server and a client computer (called as “client”) so as to count the number of requests from the client with the print server, set the number of the requests to a predetermined limited number, to notify the client in case of more than the limited number that the request is not acceptable and to keep process loads of the server in control.
[0006] However, according to the above described technology, in the printing system, the print server determines whether or not to accept the requests from the client, giving rise to, therefore, a problem that the other clients will not be able to utilize the print server in the case where a client issues a great number of requests.
[0007] Moreover, even in case of rejecting the requests from clients, as the number of clients increases and requests will become abundant, the loads for processing the rejection of the print sever will increase, giving rise to a problem that the print server will incur many loads for processes which are not the original objects.
[0008] On the other hand, employment of respective highly value added functions into a print server has resulted in assumption of requests for various kinds of processes from clients, having brought about further necessity for alleviating the loads born by the print server appropriately.
[0009] In the case where the print server simply monitors the number of fluctuating requests which is taken as a parameter to determine whether or not to accept the requests, even when to calculate the same total loads of ten requests, types of those requests bring about big differences on process loads of the print server, giving rise to a problem that it is not at all an appropriate load assessment.
[0010] In addition, as a result of problems as described above, there is a problem that operations of the print server will become unstable and will become a less reliable printing system.
[0011] An object of the present invention is to provide a scheme that holds back loads born by a print controlling apparatus capable of communication with an information processor, secure a constant level of usability related to printing by users and can establish a highly reliable printing system.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is conceived as a response to the above-described disadvantages of the conventional art.
[0013] According to one aspect of the present invention, preferably, with a scheme in an information processor comprising an issuing means for issuing a request for process to a print controlling apparatus, load is calculated for each of a number of requests that have been issued from the information processor to the print controlling apparatus but have received no response from the print controlling apparatus, and issuance of requests from the information processor is restrained based on the calculated total loads. Thereby, holding back loads born by a print controlling apparatus capable of communication with an information processor, a constant level of usability related to printing by users can be secured and a highly reliable printing system can be established.
[0014] Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures there.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a block diagram showing a configuration of an information processing system of the present invention;
[0016] FIG. 2 is a block diagram describing a configuration of the information processor shown in FIG. 1 ;
[0017] FIG. 3 is a table exemplifying a memory map of the RAM 202 shown in FIG. 2 ;
[0018] FIG. 4 is a table exemplifying a memory map of the FD 204 shown in FIG. 2 ;
[0019] FIG. 5 is a pictorial diagram showing the relationship with the FD drive 203 and the FD 204 which is inserted to the FD drive 203 ;
[0020] FIGS. 6A and 6B are schematic diagrams showing functions of a printing system of the present invention;
[0021] FIG. 7 is a table exemplifying a configuration of message transmitted and received between the client 102 having been shown in FIG. 1 and the server computer 101 or the server program in the network printer 105 ;
[0022] FIG. 8 is a table exemplifying a request load table 620 having been shown in FIG. 6 ;
[0023] FIG. 9 is a table exemplifying transmission threshold value information 630 having been shown in FIGS. 6A and 6B ;
[0024] FIG. 10 is a table exemplifying the request managing table 610 having been shown in FIGS. 6A and 6B ;
[0025] FIG. 11 is a set of tables exemplifying the post-transmission request information 640 having been shown in FIGS. 6A and 6B ;
[0026] FIG. 12 is a flow chart exemplifying a request transmission process;
[0027] FIG. 13 is a flow chart detailing the initialization process of the managing part having been shown in FIG. 12 ; and
[0028] FIG. 14 is a flow chart detailing the initialization process of the request load acquiring part, in the managing part having been shown in FIG. 13 ;
[0029] FIG. 15 is a flow chart detailing request reception process having been shown in FIG. 12 ;
[0030] FIG. 16 which is composed of FIGS. 16A and 16B are flow charts detailing request transmitting process having been shown in FIG. 12 ;
[0031] FIG. 17 is a set of tables exemplifying the post-transmission request information 640 subject to execution of request transmitting process having been shown in FIGS. 16A and 16B ;
[0032] FIG. 18 is a flow chart showing the process of response receiving part 604 having been shown in FIGS. 6A and 6B ; and
[0033] FIG. 19 is a flow chart detailing the request canceling process having been shown in FIG. 12 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] A preferred embodiment of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.
Embodiment 1
[0035] With reference to the accompanied drawings, preferable embodiment of the present invention will be described as follows.
[0036] FIG. 1 is a block diagram describing a configuration of an information processing system to which the present invention is applicable. Here, it is assumed that one or a plurality of client computers are brought into connection with the present system.
[0037] In FIG. 1 , reference numerals 102 , 103 and 104 denote information processors as client computers (clients) which are brought into connection with a network 106 with network cables such as Ethernet™ and the like. Each client apparatus 102 to 104 is capable of executing respective types of programs such as application program and the like, and comprises a printer driver mounted and having functions to convert print data into a printer language corresponding to the printer. Reference numeral 101 denotes a server (hereinafter to be referred to as “print server”) of the present embodiment, which is brought into connection with the network 106 with a network cable. The print server 101 functions as a print controlling apparatus, storing data for printing to be transmitted to the network printer 105 , monitoring the usage status of the network 106 , managing a plurality of printers brought into connection with the network 106 and implementing a scheduling process on print jobs as described in FIGS. 6A and 6B to be described below.
[0038] Here, the clients 102 to 104 and the print server 101 can be configured by storing the print controlling program into general information processors in an executable fashion so as to proceed with different controls individually.
[0039] In addition, in case of using general information processor as the print server 101 , it can be provided with function of clients 102 to 104 at the same time. The print server 101 in the present embodiment further comprises functions as a print controlling apparatus, storing a print job containing print data outputted from the clients 102 , 103 and 104 to make the printer print; or receiving a print job not containing print data from the clients 102 , 103 and 104 , managing the print order of the clients 102 , 103 and 104 , and notifying the client in turn of printing of permission of transmission of the print job containing print data; and acquiring status of the network printer 105 or respective types of information on a print job to notify the clients 102 , 103 and 104 thereof and the like.
[0040] Reference numeral 105 denotes a network printer, which is brought into connection with the network 106 via a not shown network interface. The network printer 105 analyzes the print job containing print data transmitted from the client computers 102 to 104 to convert it into a dot image page by page, and implements printing page by page. In addition, the network printer 105 is capable of providing the print server 101 or the clients 102 to 104 with functions of managing print jobs ruled by ISO10175 (DPA: Document Printing Application).
[0041] In addition, the network printer 105 or the network interface card thereof may be configured to have functions implemented by the print server 101 or partial server function thereof. That is, the print server 101 to be described below will not be limited to the separate mode other than the network printer 105 as in FIG. 1 in particular, but may be a part of the network printer 105 (network interface card).
[0042] Reference numeral 106 denotes a network, which brings the clients 102 , 103 and 104 , the server 101 , the network printer 105 and the like into connection and may be wireless or cabled.
[0043] In addition, the drawing shows only one network printer 105 , but actually, a plurality of network printers may be brought into connection. Moreover, this network printer 105 is equivalent to a device 614 to be described later, and it goes without saying that image forming apparatuses in various types of recording systems selected from the group consisting of laser beam printers in an electrophotographic system/photocopiers/digital complex machines/facsimiles, printers in ink-jet system/digital complex machines and the like are applicable to this device 614 .
[0044] FIG. 2 is a block diagram describing a configuration of the information processor utilizable to the clients 102 to 104 and the print server 101 in the present embodiment. As described above, the clients 102 , 103 and 104 as well as the print server 101 are realizable by an information processor having likewise hardware configurations. FIG. 2 will be described as a block diagram describing a configuration of clients and a server as follows.
[0045] In FIG. 2 , reference numeral 200 denotes a CPU being control means of the information processor for executing application programs stored in a hard disk (HD) 205 , a printer driver program, the OS or a network printer control program of the present invention and the like and for controlling to temporarily store into a RAM 202 the information necessary for executing the programs and files, etc.
[0046] Reference numeral 201 denotes a ROM, which stores inside it programs such as basic I/O program and the like, font data used at the time of document processing and respective types of data such as data for templates and the like. Reference numeral 202 denotes a RAM for providing temporary storage means, which functions as the main memory of the CPU 200 , the work area and the like. Reference numeral 203 denotes a flexible disk (FD) drive, which can load programs stored in the FD 204 as storage media via a FD drive 203 as shown in FIG. 5 to be described later and the like onto the present computer system. Reference numeral 204 denotes a flexible disk (FD) as storage media being storage media where computer readable programs are stored. Here, as storage media, without being limited to the FD, any media such as a CD-ROM, a CD-R, a CD-RW, a PC card, a DVD, an IC memory card, an MO, a memory stick and the like can be utilized.
[0047] Reference numeral 205 denotes one external storage apparatus, which is a hard disk functioning as a large capacity memory. In the HD 205 , application programs, a printer driver program, the OS, a network printer controlling program, related programs and the like are stored. In addition, the spooler being spool means is secured in this HD 205 . Here, the spool means refer to a client spooler for the clients 102 to 104 , and a server spooler for the print server 101 . In addition, the print server 101 stores job information in receipt from the clients 102 to 104 , and a table for implementing order control is generated and stored in this exterior storage apparatus (HD 205 ) as well.
[0048] Reference numeral 206 denotes a keyboard for inputting instructions. Using the keyboard 206 , the user inputs and instructs to the client computer or an operator or a manager do to the print server an order of control commands of a device and the like. Here, in order to implement instruction and inputting, a pointing device (not shown) may be provided.
[0049] Reference numeral 207 denotes a display, which displays commands inputted from the keyboard 206 , the status of the printer and the like. Reference numeral 208 denotes a system bus, which governs the data flow inside the computer being a client and the print server. Reference numeral 209 denotes an interface, and via the interface 209 , the information processor is brought into connection with the network 106 , which will enable exchange of data with external apparatuses.
[0050] FIG. 3 exemplifies the memory map of the RAM 202 shown in FIG. 2 . FIG. 3 shows the memory map under the state that the above described network printer controlling program stored in the FD 204 is loaded onto the RAM 202 and has become executable.
[0051] The present embodiment exemplifies loading of the network printer controlling program as well as the related data directly to the RAM 202 from the FD 204 for execution, but otherwise each time the FD 204 operates the network printer controlling program, loading may be arranged to be implemented from the HD 205 where the network printer controlling program is already installed to the RAM 202 . In addition, the media storing the present network printer controlling program may be a CD-ROM, a CD-R, a PC card, a DVD, an IC memory card and the like other than the FD. Moreover, it is possible that the present network printer controlling program is stored in the ROM 201 and this is configured to become a part of the memory map so that the CPU 200 implements execution directly. In addition, the software for realizing the function equivalent to the above described respective apparatuses can be configured as a replacement of the hardware apparatuses.
[0052] In addition, the present network printer controlling program is occasionally called as a print controlling program simply. The print controlling program includes programs for controlling instruction for changing the printing site of the print job in the clients 102 to 104 and instruction for changing the print order. In addition, the print controlling program includes in the print server 101 programs for controlling order of print jobs and notifying print finalization of a print job or a request for a change in printing site and the like. In addition, for the print controlling program of the present embodiment to control like this, modules to be installed into the clients 102 to 104 and modules to be installed into the print server 101 may be divided separately. Or one print controlling program may function as the one for a client depending on the circumstances of execution, or function as the one for the print server. Or one computer can be configured to operate simultaneously or in a time-shared pseudo-parallel fashion by installation of both the modules having functions for a client and the modules to function as a print server.
[0053] In FIG. 3 , reference numeral 301 denotes a basic I/O program, which is read by the OS from the HD 205 to the RAM 202 when the power of the present controlling apparatus is switched ON and is a region where the programs having an IPL (initial program loading) function to start the operation of the OS and the like are present. Reference numeral 302 denotes an operating system (OS) and reference numeral 303 denotes a network printer controlling program, both of which are stored in the respective regions secured in the RAM 202 . Reference numeral 304 denotes the related data, which are stored in a region secured in the RAM 202 . Reference numeral 305 denotes a work area, where a work region is secured to be used at the time when the CPU 200 executes the printer controlling program ( 303 ) and the like.
[0054] FIG. 4 is a table exemplifying a memory map of the FD 204 shown in FIG. 2 . In FIG. 4 , reference numeral 400 denotes data contents of the above described FD 204 , reference numeral 401 denotes volume information showing data information, reference numeral 402 denotes directory information, reference numeral 403 denotes a network printer controlling program being a print controlling program describing the present embodiment, and reference numeral 404 denotes the related data thereof. The network printer controlling program numbered 403 has been programmed based on the flow chart described in the embodiment, and in the present embodiment, the clients and the server are configured likewise.
[0055] FIG. 5 is a pictorial diagram showing the relationship with the FD drive 203 and the FD 204 which is inserted to the FD drive 203 , and the same code is given to the corresponding component in FIG. 2 . In FIG. 5 , the network printer print controlling program as well as the related data described in the present embodiment as described in FIG. 4 are stored in the FD 204 .
[0056] Next, the print controlling process to operate based on the respective configurations having been described above will be described.
[0057] Next, an example of software configuration for transmitting a print job to the network printer 105 of a client of the present printing system will be described. FIG. 6A is a schematic diagram exemplifying a software configuration in the clients 102 to 104 . Arrows between respective components shows how a print job including a draw command having been issued from the application undergoes processing. In addition, the software configuration shown in each block is executed by the CPU 200 in FIG. 2 to realize the desired functions.
[0058] Normally, a general application program 651 such as Microsoft Word™ accepts instruction of printing, and then generates a series of draw command via the OS. The PDL driver 652 in receipt of the draw command generated via the OS generates a print job including a PDL file so that the network printer 105 can interpret the generated print job based on the series of draw command. Here, in the following description, a PDL drive will be taken as an example for description, but without being limited hereto, it goes without saying that, for example, BDL (Band description Language), a printer driver producing a compressed bit map or a mode to generate print data with an application as well as an OS but not via printer driver are applicable.
[0059] The PDL drier 652 delivers a print job to a spooler 653 to transmit to a print device.
[0060] Here, an OS is assumed to be Windows™ and therefore the spooler 653 is a Windows™ spooler. However, the OS of the computer to which the present invention is applied will not be limited to Windows™, but it goes without saying that another OS is applicable if it comprises a draw command.
[0061] The spooler 653 delivers the print job to a port monitor 654 that a user has selected and instructed via the user interface and takes a procedure to have it transmitted to the print device such as the network printer 105 and the like (the arrow a).
[0062] Here, the description will be continued in the assumption that the user has designated a port monitor 654 (hereinafter to be abbreviated as “job controlling port monitor”) which is set to transfer the print data to a job controlling print service 655 in advance to instruct printing.
[0063] In addition, print setting information such as paper sizes set via the printer driver interface, staple instruction and the like are transmitted to the job controlling port monitor 654 as well. The job controlling port monitor 654 transmits it to a print service 655 (called as “job controlling print service”) (the arrow b).
[0064] The job controlling print service 655 comprises functions for managing the transmitted print jobs as well as the status of devices. In addition, it also comprises functions of managing information such as device status notified from the print devices or job status and the like, and in addition, making a predetermined order to the print devices. This is equivalent to functions for managing device information and job information on a plurality of not shown network printers including the network printer 105 .
[0065] In addition, prior to transmission of the print data to the network printer 105 , it issues a request for print to the print job order managing function which the network printer 105 has (the arrow c), and, in case of arrival of turn based on the order managing function, transmits (the arrow e) the print data to the network printer 105 in response to the print instruction from the print controlling apparatus (network printer 105 or the print server 101 ) (the arrow d).
[0066] Upon confirmation of finalization of the print data, the network printer 105 notifies (the arrow f) the job controlling print service 655 of print finalization, and notifies (the arrow f) of the status of the network printer 105 .
[0067] The print manager 657 is a program for providing the user interface for a user to check in which state a print job is inside the job controlling print service 655 or to operate the print job. The print manager 657 exchanges information and instruction with the job controlling print service 655 via the interface (API: Application Program Interface) of the software of the job controlling print service 655 .
[0068] In addition, it comprises a function of acquiring as an event the status information of the network printer 105 which the job controlling print service 655 manages. As types of event notification, warning that the remaining amount of toner has become less, communication disorder with the clients and the device, memory shortage, notification of error/warning information that the discharge tray is full, notification of normal information that the normal state has come back from an error state and the like are assumed. The job controlling print service 655 here comprises a function of accepting notification of status such as middle of print execution of respective devices (print apparatuses) communicable via network, the power controlling state, failure information (paper jam) and the like.
[0069] FIG. 6B is a block diagram showing a controlling program 303 on an information processor to which the present invention has been applied as well as the logical structure of the related data 304 , and is equivalent to a drawing to show a part of functions of the job controlling print service 655 .
[0070] In FIG. 6B , reference numeral 601 denotes a request managing part, which manages requests to be transmitted to the server and requests already transmitted to the server waiting for a response in an identifiable fashion with managing information in FIG. 10 to be described later. Reference numeral 602 denotes a request load acquiring part, which has a function of determining a load corresponding with respective requests in accordance with instruction from the request managing part 601 .
[0071] Reference numeral 620 denotes a request load table, which provides data for determining a load corresponding with respective requests. The method of the request load acquiring part 602 to determine (identify) a load value corresponding with a request with the request load table 620 will be described later with reference to FIG. 8 .
[0072] Reference numeral 603 denotes a request transmitting part. Actually, a socket library of the OS is called, and thereafter, the data of request are sent from a communication controlling part such as a network card. In any of the present embodiment, “transmission of request” will indicate a process of causing the above described socket library and the communication controlling part to transmit a request.
[0073] In addition, the present embodiment has a function of managing a list of request transmitted to the server and waiting for a response as post-transmission request information 640 (to be described later with reference to FIG. 11 ), and halting, that is, restraining transmission to the server or resuming the restrained transmission of request in accordance with these request counts or their total loads, the threshold values stored in the transmission threshold value information 630 as well as their applying conditions (to be described later with reference to FIG. 9 ). Details will be described later with reference to FIGS. 16A and 16B to FIG. 19 .
[0074] Here, restraining process will be described with the term “halt” hereunder. This “halt” includes various processes to arrange a request so as not to be transmitted as a result, such as a concept of giving up transmission in case of an attempt to transmit, a concept of refraining from transmission itself from the start and the like. Reference numeral 604 denotes a response receiving part, which has function to receive a response from the server or an event notification, renew the post-transmission request information 640 and dispatch the data in receipt to the request managing part 601 . This will be described later with reference to FIG. 18 and FIG. 19 .
[0075] FIG. 7 is a table exemplifying a format of message exchanged between the clients 102 to 104 and the print server 101 or the network printer 105 in the information processing system of the present invention, showing requests specifically.
[0076] In the drawing, size 701 defines the sizes of a message in its entirety. Magic number 702 is utilized for identifying services at such a time of receiving a message in error. Type 703 spells out message types. In the embodiment of the present invention, at least two types, that is, “request” and “response” will work well, but “event” and the other types may be added.
[0077] Here, “request” is a message for a client to ask the print server for a process, while “response” is a message of sending back the consequence of the process by the print server in accordance with the above described request.
[0078] “Event” is a message for notifying a client from the print server on a non-synchronized fashion of changes of information that the print server manages. RequestID 704 is an ID admitted on all requests issued from each client in an identifiable fashion respectively and is utilized to be brought into corresponding with a corresponding “request” at the time of receiving “response” or “event”.
[0079] Api 705 is an identifier for showing specific contents (command) of process such as a request for response on status to the network printer 105 , and the process to be executed in accordance with this number should be agreed between the clients and the print server in advance. Parameter 706 is a region where to store arguments and responded data corresponding with the contents (command) of process, and is formatted on each api so that the contents thereof is different on each message.
[0080] FIG. 8 is a table exemplifying a request load table 620 in the information processing system to which the present invention is applied, and is used for recognizing respective loads on a plurality of requests, on calculation of load total counts (also called as total loads). The present table is read into RAM 202 from the hard disk 205 in a program initialization process to be described later ( FIG. 12 to FIG. 14 ). The request load table 620 in the present invention is capable of defining a load value on each api (command), and can set a default value as a whole.
[0081] According to FIG. 8 , the default is 1 point and the Subscribe Event api (numbered 1) 801 instructing subscription of request for an event is defined as 2 points. The List Jobs api (numbered 3) 803 acquiring status as well attributes of a plurality of jobs respectively or collectively bears high loads and therefore is defined as 10 points, and Unsubscribe Event api (numbered 2) 802 for canceling or halting a request for an event is defined as 0 point. Processing the Unsubscribe Event api (numbered 2) 802 gives rise to an effect that the print server will not have to notify an event, and therefore the request load is defined as 0 point. In addition, the response process of the print server on requests will be reduced and therefore, in the case where a request being an object for cancel of the Unsubscribe Event api (numbered 2) 802 is implemented, the value of the size of recognized load multiplied by minus 1 may be regarded as the size of the load for the Unsubscribe Event api (numbered 2) 802 .
[0082] The request load acquiring part 602 receives a request for acquiring load with the api number as argument from the request managing part 601 , and then shall implement searching and recognition of the table defined in FIG. 8 , and if a corresponding api number exists, respond with the load value thereof, and if no corresponding number exists, respond with 1 point defined by the default.
[0083] Comprising this function (configuration) in FIG. 8 , a client takes loads on respective requests into consideration to implement calculation of total loads of an issued plurality of requests, and therefore an appropriate load assessment on requests can be implemented, compared with a mode of a print server to determine only from request counts whether or not to accept a request from a client.
[0084] For example, there is a sizable difference in loads born by the print server between registration of an event of print job finalization notice and a request for a list of a plurality of print jobs managed by a print apparatus, and in such a case, loads can be assessed appropriately.
[0085] FIG. 9 is a table exemplifying transmission threshold value information 630 . The present table is read into RAM 202 from the hard disk 205 in a program initialization process to be described later ( FIG. 12 to FIG. 13 ).
[0086] As the transmission threshold value information in the present invention, a transmittable request counts 631 , a threshold value of transmittable load 632 and method of application thereof 633 can be designated. These values will be referred to in the request transmission process to be described in FIG. 14 . Here, in the case where 0 is designated respectively to the transmittable request counts 631 and the threshold value of transmittable load 632 , individual values thereof will not be applied. That is, in the case where 0Request is designated to the transmittable request counts and threshold value of transmittable load 632 , transmission control based on post-transmission request counts is not implemented but only control based on load values is implemented.
[0087] In addition, there are two methods in the method of applying threshold value of transmittable load, that is, a method of “halting so as not to exceed threshold value” and a method of “halting once reaching threshold value or more” in terms of the load total counts being the sum of respective post-transmission request loads, and FIG. 9 presents an appearance where the method of “halting once reaching threshold value or more” is selected as the current settings. In addition, as for the interpretation on not less than the threshold value and not more than threshold value, either the interpretation that the request transmission is halted at the same value as the threshold value or the interpretation that the request transmission is halted in the case where the total loads get higher or lower than the threshold value will do.
[0088] As for the method of “halting so as not to exceed threshold value”, in the case the summed value of total loads of post-transmission and response pre-reception request and the load value of pre-transmission request already issued and to be transmitted now exceeds the set threshold value of transmittable load 632 , transmission of that request will not be allowed. In addition, as for the method of “halting once reaching threshold value or more”, regardless of load value of a request to be transmitted now, if the current load value is nor less than the value of the threshold value of transmittable load 632 , no new request transmission will be implemented.
[0089] Comprising the both of these configurations in FIG. 9 and the above described FIG. 8 , particular effects of, for example, enabling a plurality of cases of registration of print job finalization notifying event, enabling assurance to each client on the operation that only one request for a list of print jobs is allowed and enabling not only appropriate assessment of loads of the print server but also security of constant usability of the printing system in each client will become obtainable in terms of usability as well.
[0090] FIG. 10 exemplifies a request list managed in the request managing table 610 at a certain point of time. As can be seen in the drawing, 6 requests exist and two requests of RequestID 100 and 101 have already been transferred to the server, and 4 requests of RequestID 102 , 103 , 104 and 105 are waiting for transfer. Based on this table shown in FIG. 19 , respective loads of a plurality of requests already issued from the client but left with no response from the print server are recognized, the total load of a plurality of requests is calculated based on the recognized respective loads and issuance of requests is restrained at the client side based on the calculated total loads.
[0091] The request managing table 610 manages information to become necessary for preparing a message to be transferred to the server ( FIG. 7 ) and values of loads in respective requests in addition to status of respective requests. Here, in the embodiment of the present invention, it is assumed that the load of request is determined every time of accepting a request and the entry is added to the managing table, but such a configuration may be adopted that, without providing the request managing table 610 in FIG. 10 with load values but making direct reference to the request load table 620 shown in FIG. 8 , the total load of the post-transmission requests is calculated.
[0092] In addition, the request managing table 610 shown in FIG. 10 enables management of requests already transmitted to the print server and requests waiting for transmission in an identifiable fashion, and enables calculation of more accurate load total counts based on requests already transmitted and waiting for response except requests waiting for transmission, as shown in FIG. 11 .
[0093] FIG. 11 is a set of tables exemplifying the post-transmission request information 640 at the same timing as in FIG. 10 . Two requests of RequestID 100 and 101 are recorded in the post-transmission load managing table 642 together with their load values. In addition, in order to simplify calculation, total counts of requests and total loads of those requests included in post-transmission load managing table 642 are kept as the post-transmission request current value 641 .
[0094] The post-transmission load managing table 642 shows that there are entries of RequestID 100 and 101 , therefore making 2 Request of the post-transmission request counts of the post-transmission request current value 641 and making 4 points of post-transmission load total counts. These data are renewed by the request transmitting process, the response receiving process and the request canceling process to be described later.
[0095] FIG. 12 is a flow chart showing a schematic operation of a request controlling program in the information processing system in the present invention. Here, since the present flow chart extracts only portions related to the points of the present invention, it goes without saying that inclusion of any not shown process will fulfill the present invention and applicable.
[0096] At first, the step S 1201 implements the process of initializing the request managing part 601 . This will be described later with reference to FIG. 13 and FIG. 14 .
[0097] In the subsequent steps S 1202 and S 1203 , the request transmitting part 603 and the response receiving part 604 are initialized and the step moves to the step S 1204 , entering the loop of waiting for an event.
[0098] In the step S 1205 , in receipt of an event of program finalization, the present program comes to an end. On the other hand, in the case where the inputted event is determined to be other than “finalization” in the determination by the request managing part 601 of the step S 1205 , the request managing part 601 determines in the step S 1206 whether or not that event is an event of accepting the request for transmission. In case of determination of “YES”, the step S 1207 implements process of accepting the request to be described later ( FIG. 15 ) and moves to the step S 1204 of waiting for an event.
[0099] On the other hand, in the case where the determination in the step S 1206 turns out to be the determination of “NO”, in the step S 1208 the request managing part 601 determines whether or not the event is a request for cancellation. In case of determination of “YES”, cancellation process of the step S 1209 ( FIG. 12 ) is implemented and the step moves to the step S 1213 .
[0100] On the other hand, in the case where the determination in the step S 1208 turns out to be the determination of “NO”, the step S 1210 determines whether or not the event is a response receiving event (corresponding with the step S 1807 in FIG. 18 ) from the response receiving part 604 . In case of “NO”, the step jumps to the step S 1213 . In case of “YES”, the message in receipt undergoes determination whether “response” or “event”, and in case of “response” and a request for not transiting to “waiting for an event”, the step S 1211 deletes the entry of the applicable request from the request managing table having been shown in FIG. 10 , and subsequently the step S 1212 implements the other processes on the response.
[0101] The other process included, for example, renewal of GUI, transmission to a response to the superior system, renewing process of internal data managed by the information processing system of the present invention and not related to the present invention and the like.
[0102] Subsequently, the step S 1213 determines whether or not pre-transmission request exists. In case of “YES”, since four pre-transmission requests (RequestID 102 to 105 ) exist in FIG. 10 specifically, the subsequent step S 1214 implements issuance of request from a client, that is, the request transmitting process via the request transmitting part 603 . The request transmitting process will be described later with reference to FIGS. 16A and 16B .
[0103] Here, the timing for execution of the step S 1214 is in case of the step S 1213 resulting that a pre-transmission request exists in managed information shown in FIG. 10 , but without being limited hereto, regardless of input of events, the flow chart shown in FIG. 12 may be arranged to be executed regularly.
[0104] FIG. 13 is a flow chart showing the initializing process of the request managing part 601 and corresponds with the step S 1201 in FIG. 12 . The initializing process of the request managing part 601 initializes the request managing table 610 as well as the post-transmission request information 640 and prepares the transmission threshold value information 630 .
[0105] At first, the step 1301 sets the initial value to the threshold value of transmittable load 632 . Subsequently, the step S 1302 sets the initial value to the transmittable request counts 631 .
[0106] Subsequently, the initial value for the method of applying threshold value of transmittable load 633 is set. Subsequently, the step S 1304 determines whether or not a file of transmission threshold value settings exists. In case of determination of “YES”, the step S 1305 determines whether or not a setting on the threshold value of transmittable load 632 exists. In case of determination of “YES”, the step S 1306 renews (changes) the threshold value of transmittable load 632 .
[0107] Subsequently, the step S 1307 determines whether or not any setting on transmittable request counts 631 exists. In case of determination of “YES”, the step S 1308 renews the transmittable request counts 631 and changes the size of loads corresponding with each request as having been described in FIG. 8 .
[0108] Subsequently, the step S 1309 determines whether or not any setting on the method of applying threshold value of transmittable load 633 exists. In case of “YES”, the step S 1310 renews (changes) the method of applying threshold value of transmittable load 633 . Subsequently the steps S 1311 initializes the request load acquiring part 602 and the initialization process of the request managing part comes to an end.
[0109] Execution of the flow chart in FIG. 13 enables changes in settings related to conditions of restrains-on transmission of requests (threshold value of transmittable load, transmittable request counts and the like), and enables changes in conditions so as to make it difficult to restrain requests from such a client who tends to issue a great number of respective kinds of requests starting with introduction of a print job compared with other clients. In addition, as a condition of restraint, such a case is assumed that includes any one of or a plurality of the transmittable request counts 631 to the method of applying threshold value of transmittable load 633 as described in FIG. 9 .
[0110] FIG. 14 is a flow chart of the request load acquiring part 602 , and corresponds with the step S 1311 in FIG. 13 . In the initializing process of the request load acquiring part 602 , the request load table 620 is prepared.
[0111] At first, the step 1401 sets the initial value to the request load table. Subsequently, the step S 1402 determines whether or not a file of request load settings exists, and in case of determination of “YES”, the step S 1403 renews (changes) the API designated by the file with the designated load value, and the initializing process of the request load acquiring part 602 comes to an end. Here, any type of API designated by the file shall be designatable.
[0112] This process in FIG. 14 enables change in sizes of loads corresponding with respective requests, and therefore in the case where the size of a load on a request (API) is inappropriate for the operation of an actual printing system, the size can be changed appropriately, making better printing environments realizable.
[0113] FIG. 15 outlines a request reception process and corresponds with the step S 1207 in FIG. 12 . When a request transmitting event occurs in accordance with instruction of a user via the print manager 657 or internal application instruction, the step S 1501 acquires a load value corresponding with the API from the request load acquiring part 602 and the subsequent step S 1502 prepares an entry specifying the request so that the entry is added to the above described request managing table 610 ( FIG. 10 ).
[0114] FIGS. 16A and 16B are flow charts detailing the request transmitting process and corresponds with the step S 1214 in FIG. 12 . Here, details will be described in the assumption that an entry of RequestID 102 in the request managing table 610 is transmitted.
[0115] In the request transmitting process, at first the step S 1601 inputs information on the request for transmission (the top request under pre-transmission in FIG. 10 is taken out). The step S 1601 will input various requests having been described in FIG. 8 (the top request under pre-transmission in FIG. 10 is taken out), but in the drawing, in order to make the description easy to understand, the description will be made as follows in the assumption that load value=10, api=3 and Parameter=(Start=1, Count=100) are inputted (the top request under pre-transmission in FIG. 10 is taken out).
[0116] The subsequent step S 1602 acquires transmittable request counts 631 in the transmission threshold value information 630 . The subsequent step S 1603 acquires the threshold value of transmittable load 632 and the method of applying threshold value of transmittable load 633 .
[0117] The subsequent step S 1604 determines whether or not the transmittable request counts is 0 or more.
[0118] Here, in case of “NO”, determination on the transmittable request counts will not be implemented and the step jumps to the step S 1607 .
[0119] In the case where the determination in the step S 1604 turns out to be the determination of “YES”, the step S 1605 acquires the post-transmission request current value 641 (2 Request in FIG. 11 ). In the case where the determination in the step S 1606 turns out to be the determination the post-transmission and response pre-reception request counts are not less than the transmittable request counts, the transmission process is not implemented, and the step S 1612 prepares an error response, and the transmission process comes to an end.
[0120] On the other hand, in the case where determination on transmission counts was not implemented, or in the case where determination on transmission counts a result of the determination being “OK”, the step S 1607 determines whether or not the threshold value of transmittable load 632 is larger than 0. In case of 0 or less, determination based on load will not be implemented, and the transmission process described in the steps S 613 to S 1618 will be implemented. A mode that does not take load into consideration can serve a user, such as a manager, who has necessity for issuing a great number of requests.
[0121] In the case where the determination in the step S 1607 turns out to be the determination of “YES”, the step S 1608 acquires the post-transmission load total counts 641 (4 Point in FIG. 11 ). Here, determination on the load total counts 641 and the threshold value of transmittable load 632 is different in accordance with the method of applying threshold value of transmittable load 633 , but in any case, respective loads of a plurality of requests that are already transmitted from the client and waiting for response from the print server can be recognized with the transmission threshold value information 630 in FIG. 9 , and the calculated results based on the recognized respective loads will become the load total counts acquired by the step S 1608 .
[0122] In the case where the step S 1609 does not select “halt once reaching threshold value or more” by the method of applying threshold value of transmittable load 633 , the step S 1610 determines whether or not the sum of the post-transmission load total counts 641 (4 points) and the load of the request to be transmitted now (10 points in the step S 1601 is larger than the threshold value of transmittable load 632 (12 points in FIG. 10 ). In the case where the determination turns out to be larger, the step transits to the step S 1612 and the transmission process is not implemented.
[0123] On the other hand, in the case where the step S 1609 has come up with determination of “YES”, the step S 1611 determines whether or not the total load counts 641 that are given by requests that are already transmitted and waiting for response from the print server is not less than or exceeds the threshold value of transmittable load 632 , and in case of “NO”, the step transits to the step S 1612 and the transmission process is not implemented.
[0124] In the case where a result of the above described determination is determined to fulfill transmittable conditions, the actual transmission process is implemented. Here, determination of the step S 1609 may be omitted so that the step moves to the step S 1611 without implementing determination in the step S 1608 through the step S 1609 .
[0125] The step S 1613 implements data format conversion, and a data stream is converted into the network format having been shown in FIG. 7 from the host format. The subsequent step S 1614 issues request message onto the network via the request transmitting part 603 .
[0126] The subsequent step S 1615 renews the post-transmission load managing table 640 and adds an entry. Subsequently, the steps S 1616 and S 1617 renew the post-transmission request current value 641 while the step S 1618 responds with “success” and the transmission process comes to an end. When the transmission process comes to an end, the status of the request in the request managing table 610 transits from “Wait” to “Sent”.
[0127] The flow charts in FIGS. 16A and 16B can alleviate determination process load at the print server side, compared with a mode of a print server to determine whether or not to accept a request from a client. In particular, in the case where the print server is co-owned by a plurality of clients, such an effect becomes attainable that the determination process for permission on issuance of requests from clients is deconcentrated.
[0128] Moreover, with a mode of a print server to determine whether or not to accept a request from a client, in case of refusing a request, not only the determination process load of the print server increases but also notification of refusal from the print server to the clients as well as retrial of issuance of request from clients linked to receipt of the refusal will be brought about, giving rise to a problem that the traffic quantity will be caused to increase, but the flow charts in FIGS. 16A and 16B can eliminate this problem.
[0129] FIG. 17 shows how the post-transmission request information 640 changes after finalization of the request transmission process. Compared with FIG. 10 , the post-transmission load total counts in the post-transmission request current value 641 ′ are 14 Point (increase of 10 Point), the post-transmission request counts are 3 Request (increase of 1 Request) and an entry of RequestID 102 is added to the post-transmission load managing table 642 ′.
[0130] FIG. 18 is a flow chart showing an outline of process of response reception in the response receiving part 604 . Details of process of the step S 1211 as well as the step S 1212 having been described in FIG. 12 will be shown.
[0131] In receipt of a message (the structure is described in FIG. 7 ) transmitted from the print server 101 in the step S 1801 , the step S 1802 extracts RequestID from the message, and the step S 1803 searches the post-transmission load table 642 based on the extracted RequestID.
[0132] In the case where the step S 1804 has searched a corresponding request and the request is not an event type (a type of request to receive, in an asynchronized fashion, event message once or more times other than the response from the server), the step S 1805 deletes the searched table from the post-transmission load managing table 642 and renews the load managing table 642 .
[0133] Subsequently, the step S 1806 and the step S 1807 subtract only the value corresponding with the deleted table from the post-transmission request counts and the post-transmission load total counts in post-transmission request current value, and renew the post-transmission request current value 641 as well. Thus, the process of the steps S 1806 and S 1807 can subtract loads corresponding with the requests to which the print server has responded from the load total counts.
[0134] Subsequently, the step S 1808 notifies the request managing part 601 of a response receiving event.
[0135] In addition, execution of the flow chart in FIG. 18 gives rise to from the case where the calculated load total counts are not less than a predetermined threshold value or higher than the threshold value to the case of less than the threshold value or not more than the threshold value (the steps S 1610 and S 1611 determines as “NO”), and in that case, transmission of request restrained under pre-transmission (retransmission) is implemented by the request transmitting part 603 (the step S 1614 ). And then the pre-transmission requests subscribed at the client side will be sequentially sent to the print server 101 .
[0136] FIG. 19 is a flow chart detailing the process of canceling request transmission from a client to the server, and corresponds with the step S 1209 in FIG. 12 .
[0137] At first, the step S 1910 inputs an ID (Request ID) for identifying a request to be cancelled. Subsequently, the step S 1902 searches the request managing table 610 for the applicable request.
[0138] In the case where the step S 1903 determines that a corresponding request exits, the step 1904 deletes the applicable request from the request managing table 610 . Subsequently, the post-transmission request information 640 is renewed. In addition, in case of having deleted the request from the request managing table 610 , correspondingly an order for deleting the request already transmitted from the client to the printer side (for example, UnsubscribeEvent api (number 2) or cancel request) is transmitted so as to alleviate loads at the printer side.
[0139] The step S 1905 searches the post-transmission load table 642 for a table corresponding to the request ID.
[0140] In the case where the step S 1906 determines that a corresponding table exists, the step S 907 subtracts one (1) from the post-transmission load counts of the post-transmission request current value 641 . Subsequently, the step S 1908 subtracts only the load value of the entry searched in the step S 1905 from the post-transmission load total counts of the post-transmission request current value 641 .
[0141] Subsequently, the step S 1909 deletes the applicable request from the post-transmission load table and the cancel process comes to an end.
Embodiment 2
[0142] In Embodiment 1, it has been described that the total loads are calculated for requests yet to be responded by the print server 101 among a plurality of requests issued from a client, and in accordance with the calculated total loads, issuance of requests from the client is restrained, but this will not limit any way.
[0143] With regard to the point that respective loads are calculated for the requests yet to be responded by the print server 101 among the plurality of requests issued from one client to the print server 101 and, based on the recognized respective loads, the total loads of the request are calculated, it may be implemented by the print server or another apparatus.
[0144] That is, such a mode that the print server 101 comprises the functions described in FIGS. 6A and 6B and FIG. 8 of Example 1, moreover supervises and manages the functions described in FIG. 9 , FIG. 10 , FIG. 11 and FIG. 17 corresponding with each client being the source of request issuance and moreover executes process of flow charts in FIG. 15 , FIGS. 16A and 16B , FIG. 18 and FIG. 19 can be assumed. In case of this mode, the respective flow charts in FIG. 15 , FIGS. 16A and 16B and FIG. 18 will be implemented to each client individually. In addition, the process of the step S 1614 in FIGS. 16A and 16B is realized by replacement with the process of the print server 101 to receive requests from a client
[0145] In addition, also in this Embodiment 2, taking loads on respective requests into consideration to implement calculation of total loads of an issued plurality of requests, and therefore an appropriate load assessment of individual apparatus on requests can be implemented, compared with a mode to determine only from request counts whether or not to accept a request from a client.
[0146] For example, in the aspect that there is a sizable difference in loads born by the print server between registration of an event of print job finalization notice and a request for a list of a plurality of print jobs managed by a printer, and in such a case, loads can be assessed appropriately, making particular effects likewise Example 1 attainable as well.
[0147] This application claims priority from Japanese Patent Application No. 2004-221837 filed Jul. 29, 2004, which is hereby incorporated by reference herein. | An object is to provide a scheme that holds back loads born by a print controlling apparatus capable of communication with an information processor, secure a constant level of usability related to printing by users and can establish a highly reliable printing system. With a scheme in an information processor including an issuing unit for issuing a request for process to a print controlling apparatus, a load is calculated for each of a number of requests that have been issued from the information processor but have received no response from the print controlling apparatus, and issuance of requests from the information processor is restrained based on the calculated loads. | 6 |
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to product design and, in particular, to capturing decisions made during project design.
[0002] Many projects require multiple working groups working in multiple stages to achieve a desired result. Typically, at least some planning is performed before the project is begun to define and coordinate the different stages and assign responsibility for them to certain individuals.
[0003] One paradigm for project development is the so-called “waterfall model.” The waterfall model is a rigidly structured, sequential project development process that flows from one phase to another. In the waterfall process, the project does not move from a current phase to the next phase until the current phase is completed. In this manner, progress is seen as flowing steadily downwards (like a waterfall) through the phases of the development. The waterfall model was originally used for manufacturing projects and was an early model used in the development of software where it experienced varying degrees of success. In the waterfall model a single document typically defines and tracks design decisions that are made during the planning phase. Such a document typically cannot easily accommodate design decision changes.
[0004] Another development process that may be employed in project development is the “agile” development model. In the case of a software project, such a model is commonly referred to as “agile software development.” Agile software development may generally be defined as including iterative and incremental software development stages, where the requirements and solutions for each stage evolve through collaboration between self-organizing, cross-functional teams.
[0005] In the agile development process architecture and design of software is evolutionary. Consequently there is less emphasis of the production of large, very detailed architecture/design documents up-front as in traditional waterfall development processes. Instead design happens just-in-time and utilizes more flexible technologies to capture the essence of the design.
[0006] A common technology is a wiki, which is a web-enabled service that allows users to input information into one location that is visible to other users. However, while using a wiki to capture design decisions is very flexible and corresponds well to the agile software design principles, it does not provide a structure for capturing key information that may be needed at later times. For example, some types of decisions, such as using .NET rather than Java for enterprise integration, frame the approach to implementing solutions technically. These types of decisions and the reasoning behind them need to be very clearly visible to developers for the lifetime of the product. But when they are captured in a wiki they may not have this visibility.
BRIEF DESCRIPTION OF THE INVENTION
[0007] According to one aspect of the invention, a system for capturing project design decisions that includes a computing system and logic executing on the computing system is disclosed. The logic implements a method that includes: maintaining a main page and at least one secondary page; allowing users of the computing system to provide information to the at least one secondary page; forming a secondary page summary text portion on one of the secondary pages; and linking the secondary page summary text portion to a summary text portion on the main page, wherein authorization to cause the linking is limited to a subset of the users.
[0008] According to another aspect of the invention, a computer-based method for capturing project design decisions is disclosed. The method of this aspect includes: providing a main page and at least one secondary page; receiving information from users and placing it on the secondary page; forming a secondary page summary text portion on one of the secondary pages in response to a tag command received from an authorized user; and linking the secondary page summary text portion to a summary text portion on the main page.
[0009] According to another aspect of the invention, a computer program product for capturing project design decisions is disclosed. The computer program product of this aspect includes a computer-readable storage medium having instructions embodied thereon, which when executed by a computer cause the computer to implement a method that includes: providing a main page and at least one secondary page; receiving information from users and placing it on the secondary page; forming a secondary page summary text portion on one of the secondary pages in response to a tag command received from an authorized user; and linking the secondary page summary text portion to a summary text portion on the main page.
[0010] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0011] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 illustrates several web pages that form a system according to one embodiment of the present invention;
[0013] FIG. 2 shows an example user screen illustrating an operation according to one embodiment; and
[0014] FIG. 3 shows an example of a computing system on which embodiments of the present invention may be implemented.
[0015] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As described above, when design decisions are captured in a wiki, the reasons for these decisions and, indeed, the decisions themselves may be lost or difficult to find. Accordingly, in one embodiment, a technical effect of the invention disclosed herein includes providing a structure for recording design decisions in a wiki page and a toolset for easily “tagging” and “promoting” the information related to the design decisions to a main page that is not subject to change or modification most of the users of the wild page.
[0017] FIG. 1 illustrates several web pages that form a system 100 according to one embodiment of the present invention. It shall be understood that the system 100 may be so-called “wiki system,” or simply a “wiki” herein. The system 100 can be powered by any type of wild software currently known or later developed and allows, at least in a limited sense, any user who has access to the system 100 to post information to the system. The system 100 can be implemented on one or more computing devices such as the computing system shown, for example, in FIG. 3 . Of course, the computing system of FIG. 3 can also be referred to as a server in some embodiments.
[0018] In one embodiment, the system 100 includes a main page 102 . The main page 102 can include, for example, one or more different summary sections 104 in one embodiment. In one embodiment, the summary sections 104 include a design principle, a design decision or a system quality. Of course, the summary sections 104 could include other information. In one embodiment, the information in the summary sections 104 is information that is usually contained in architecture specification documents. However, in one embodiment and in contrast to a typical design specification document, on the main page 102 the summary sections 104 do not include accompanying detail about the decision or how those decisions were reached. As such, in one embodiment the main page 102 can serve as the initial point of contact for those users who wish to understand what design principles, decisions, etc. are for a particular product. In one embodiment only one or a limited number of users are allowed to change or otherwise manipulate the main page 102 .
[0019] In one embodiment, one or more of the summary sections 104 include a summary text portion 106 . The summary text portion 106 can include, in one embodiment, a brief summary of the particular design principle or other information in the summary section 104 . One or more of the summary text portions 106 can be linked by hyperlinks 107 to one or more different, secondary pages 108 , 110 . The ability to add the hyperlinks 107 from the main page 102 to another page can be limited to one or a limited number user in one embodiment.
[0020] In one embodiment, any user of the system 100 can post information to the secondary pages 108 , 110 . Of course, access can be limited to specific users in one embodiment. The number of secondary pages 108 , 110 is not limited and can vary from one to any value. In one embodiment, each secondary page 108 , 110 is devoted to a different topic. For example, secondary page 108 can be devoted to design principles and secondary page 110 can be devoted to system qualities.
[0021] In one embodiment, the secondary pages 108 , 110 include one more secondary page summary text portions 112 . In one embodiment, the summary text portion 106 and the secondary page summary text portions 112 are linked to one another and include the same text. Control of the linking of the summary text portion 106 and the secondary page summary text portions 112 is described in greater detail below.
[0022] As illustrated, the summary text portions 106 are linked to secondary page summary text portions 112 on different secondary pages 108 , 110 . It shall be understood that that multiple summary text portions 106 on the main page 102 can be linked to multiple secondary page summary text portions 112 on only one of the secondary pages 108 , 110 .
[0023] In one embodiment, the secondary page summary text portions 112 divide the secondary pages 106 , 108 into categories according to project and can be accessed and added to by any user of the system 100 . The secondary pages 106 also include one or more explanation sections 114 . The explanation sections 114 can include, for example, diagrams, text, or any other type of information that can record or explain design decisions. In one embodiment, the explanation sections 114 are related to the secondary page summary text portion 112 immediately preceding it.
[0024] As in any wiki system, the secondary pages 108 , 110 by their very nature evolve over time, as the design of the project is refined. In one embodiment, at key points in time a version of the secondary pages 108 , 110 can be considered “definitive.” At these key time, an authorized individual (e.g., software architects or technical leads) can “tag” that version of the secondary pages 108 , 110 such that the a particular summary text portion 106 is linked by hyperlinks 107 to the particular version of the secondary pages. In this scenario, an observer of the main page 102 would see the summary text portion 106 , click on the link and go to that version of the secondary pages 108 , 110 in the region where the linked secondary page summary text portion 112 is located.
[0025] FIG. 2 shows an example user screen 200 illustrating an operation according to one embodiment. In this example, the user screen 200 includes the main page 102 and secondary page 110 . As described above, the main page 200 includes one or more of the summary sections 104 that include summary text portions 106 . As illustrated, the secondary page 110 includes explanation sections 114 . In one embodiment, the user screen 200 also includes a tag selector 202 . It shall be understood that the tag selector 200 could be a button icon on the screen 200 , a button on a keyboard or be selectable in other manners.
[0026] In operation, a user can select one or more explanation sections 114 . In one embodiment, the user then activates the tag selector 200 causing a dialog that categorizes the type of information that is being referred to. For example, in this example, the user has selected the illustrated explanation sections 114 . The user then “tags” the section by activating the tag selector 202 . This causes a new summary section 104 (shown in dashes) to be created and it is linked to the secondary page summary text portion 112 shown (also shown in dashes).
[0027] In an alternative embodiment, the secondary page summary text portion 112 may already exist. In such an embodiment, the user selects the secondary page summary text portion 112 and the new summary section 104 is linked to it. In this embodiment, the contents of the secondary page summary text portion 112 may be replicated in the summary text portion 106 .
[0028] In one embodiment, after the tag selector 202 is activated, the user selects from a configurable selection of types for the summary section. Choices can include, for example, Design Principle, Design Decision, System Quality, or the like. In one embodiment one or more of these choices may raise a sub-types selection screen. For example, selection of System Quality may raise a sub-type selection screen where a user can select one or more of Performance, Scalability, Modularity, or the like. In one embodiment, the selected types are included in and describe the summary section 104 to which they relate.
[0029] According to one embodiment the end result is that the secondary page summary text portion 112 and the hyperlink 107 thereto allows for the information on the on the secondary page 110 to be captured, in a summary form, on the main page 102 . Thus, those who are interested can use the main page 102 to see the current state of development with respect to the design as well as going back to previous and in-progress versions of the design if necessary. As a technical effect, embodiments of the present invention reduce the need to continually maintain and update large, unwieldy documents that have traditionally been used in waterfall development. Furthermore, embodiments of the present invention have the technical effect of allowing a design team to use more free-form technology (in this case, a wiki) to describe and evolve the design of a project while still maintaining an identifiable current design and relevant design decisions.
[0030] FIG. 3 shows an example of a computing system on which embodiments of the present invention may be implemented. As discussed above, the computing system of FIG. 3 can be server that users access from other computing systems. In this embodiment, the system 100 has one or more central processing units (processors) 301 a , 301 b , 301 c , etc. (collectively or generically referred to as processor(s) 101 ). In one embodiment, each processor 301 may include a reduced instruction set computer (RISC) microprocessor. Processors 301 are coupled to system memory 314 and various other components via a system bus 313 . Read only memory (ROM) 302 is coupled to the system bus 313 and may include a basic input/output system (BIOS), which controls certain basic functions of system 300 .
[0031] FIG. 3 further depicts an input/output (I/O) adapter 307 and a network adapter 306 coupled to the system bus 313 . I/O adapter 307 may be a small computer system interface (SCSI) adapter that communicates with a hard disk 303 and/or tape storage drive 305 or any other similar component. I/O adapter 307 , hard disk 303 , and tape storage device 305 are collectively referred to herein as mass storage 304 . A network adapter 306 interconnects bus 313 with an outside network 316 enabling data processing system 300 to communicate with other such systems. A screen (e.g., a display monitor) 315 is connected to system bus 313 by display adaptor 312 , which may include a graphics adapter to improve the performance of graphics intensive applications and a video controller. In one embodiment, adapters 307 , 306 , and 312 may be connected to one or more I/O busses that are connected to system bus 313 via an intermediate bus bridge (not shown). Suitable I/O buses for connecting peripheral devices such as hard disk controllers, network adapters, and graphics adapters typically include common protocols, such as the Peripheral Components Interface (PCI). Additional input/output devices are shown as connected to system bus 313 via user interface adapter 308 and display adapter 312 . A keyboard 309 , mouse 310 , and speaker 311 all interconnected to bus 313 via user interface adapter 308 , which may include, for example, an I/O chip integrating multiple device adapters into a single integrated circuit.
[0032] Thus, as configured in FIG. 3 , the system 300 includes processing means in the form of processors 301 , storage means including system memory 314 and mass storage 304 , input means such as keyboard 309 and mouse 310 , and output means including speaker 311 and display 315 . In one embodiment, a portion of system memory 314 and mass storage 304 collectively store an operating to coordinate the functions of the various components shown in FIG. 1 .
[0033] It will be appreciated that the system 300 can be any suitable computer or computing platform, and may include a terminal, wireless device, information appliance, device, workstation, mini-computer, mainframe computer, personal digital assistant (PDA) or other computing device. It shall be understood that the system 300 may include multiple computing devices linked together by a communication network. For example, there may exist a client-server relationship between two systems and processing may be split between the two.
[0034] The system 100 also includes a network interface 106 for communicating over a network 116 . The network 116 can be a local-area network (LAN), a metro-area network (MAN), or wide-area network (WAN), such as the Internet or World Wide Web. Users of the system 300 can connect to the network through any suitable network interface 316 connection, such as standard telephone lines, digital subscriber line, LAN or WAN links (e.g., T1, T3), broadband connections (Frame Relay, ATM), and wireless connections (e.g., 802.11(a), 802.11(b), 802.11(g)).
[0035] As disclosed herein, the system 300 includes machine-readable instructions stored on machine readable media (for example, the hard disk 304 ) for capture and interactive display of information shown on the screen 315 of a user. As discussed herein, the instructions are referred to as “software” 320 . The software 320 may be produced using software development tools as are known in the art. The software 120 may include various tools and features for providing user interaction capabilities as are known in the art.
[0036] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A computer-based method for capturing project design decisions includes: providing a main page and at least one secondary page; receiving information from users and placing it on the secondary page; forming a secondary page summary text portion on one of the secondary pages in response to a tag command received from an authorized user; and linking the secondary page summary text portion to a summary text portion on the main page. | 6 |
BACKGROUND OF THE INVENTION
The instant invention relates to detectors for microwave radiation and, more particularly, to radar antennas sensitive to the polarization of the received signal.
The utilization of microwave radiation to locate and track moving objects has been known for many years and forms the basis of the many active radar systems, ranging from those tracking spacecraft to hand-held police speed-measuring units for automobiles. Such units typically emit a train of pulses at microwave frequencies from an emitting antenna and use the same antenna--generally in the form of a paraboloid--to detect echoes reflected from the target. Such units use (a) the time delay, between a given pulse in the transmission and its echo, to determine distance, (b) the Doppler effect to determine speed, and (c) antenna position to determine the line of bearing (LOB) to the target.
The instant invention addresses itself to an additional item of information which may be derived from a reflected signal, or, a priori, from a signal purposely or intrinsically emitted by the target being tracked. This information relates to the polarization of the received microwave beam. Electromagnetic radiation can be viewed as composed of two orthogonally superimposed trains of waves, e.g., by referring to such trains as being horizontally and vertically polarized in a terrestrial frame of reference. It is possible, in the case of a deliberately emitted signal beam, to define the proportion of energy sent out in the horizontal component and in the vertical component independently, by appropriately shaping the emitting conductor or array.
In the case of a reflected signal, the shape and movement of the reflecting body--and in some instances its physical make-up--can alter the polarization pattern of the radiation returned to the illuminating antenna. Whatever the reason for the variation in the polarization of a microwave signal, the knowledge of this factor can help to identify and characterize the body which is emitting it, either actively or by reflecting a beam originating elsewhere.
Conventional radar units,.being co-polar in both transmit and receive modes, cannot distinguish between different polarization patterns of incoming radiation. The commonly utilized parabolic antenna destroys this information by focusing the signal onto a single receiver, or feed; and other antenna forms, even if more sensitive to particular directions of polarization cannot, in the absence of a directional reference, provide meaningful information on the source.
Since it is a prime purpose of most radar microwave receivers to derive angle and range information on a particular target, the prior art has failed to provide any effective devices or components of a practicable nature to perform the task of differentiating polarization patterns. Proposals to employ dual-polarized feeds in conjunction with an orthomode junction to separate orthogonally polarized signals into separate channels for further processing have not been a requirement of radar systems.
The requirement for polarization information is most acute in the fields of passive sensing--associated with electronic warfare, countermeasures, reconnaissance and surveillance systems--where information is sought on all characteristics of a detected signal, including frequency, band width, pulse width, repetition rate, as well as polarization data.
OBJECTS OF THE INVENTION
It is, therefore, a principal object of the invention to provide a receiving system for microwave radiation capable of comparing the relative strengths of two, mutually orthogonal, linear wave components therein, and thereby determine the dominant polarization of the emitting and/or reflecting object which is the source of the radiation.
It is another object of the invention to teach the construction of microwave receiving systems sensitive to the direction of polarization of incoming radiation, and adaptable to different methods of analyzing the received signal.
It is yet another object of the invention to provide a microwave receiver of the aforementioned character without requiring the employment of moving components in the sensing devices therein, and thereby obviating the need for the use of rotating signal waveguide joints.
It is a still further object of the invention to teach the construction of analyzing filters for incident microwave radiation employing parallel-bar conductor arrays as polarizing filters.
It is also an object of the invention to teach the synchronization, by mechanical and/or electromechanical means, of the rotation, or scanning, of the reflecting mirror with the polarizing filter assembly, in a microwave detector of the type and kind described; thereby maintaining a constant relationship between the signal strengths transmitted through the several regions of the polarizing filter disk, independent of the instantaneous look-angle of the reflecting mirror relative-to the line-of-sight to the emitting source.
It is also an object of the invention to provide microwave detectors employing planar reflecting mirrors slaved to the rotation of a primary antenna of conventional shape.
SUMMARY OF THE INVENTION
The invention attains the aforementioned objects by providing a planar substantially rectangular mirror impelled into rotational motion about a principal axis. In a preferred embodiment of the invention, the reflecting mirror is slaved to a conventional rotating microwave antenna, e.g., in the form of a partial paraboloid with a feed at the focus to provide additional frequency coverage.
The mirror is positioned at an angle so that incoming microwave radiation is caused to be reflected into the sensor antenna along the mirror axis of rotation. The mirror angle depends upon whether the incoming signal is above, below or on the plane of the receiving antenna system. In an illustrative embodiment, the mirror is positioned at substantially 45 degrees with respect to the principal axis, so that originating radiation, when the mirror is facing the line of sight to the originating source, is reflected into a beam substantially parallel with the principal rotational axis. Suitably, the mirror is substantially centered on the rotational axis, itself, so that the reflected beam is also substantially centered on this geometric feature.
The beam of incoming radiation reflected by the planar mirror is caused to pass through a filter with three distinct regions with differing transmission characteristics. Of the three regions, one is transparent to all polarizations of the incoming radiation, a second is substantially transparent only to that portion of the radiation which was originally emitted by the source with a horizontal polarization, and the third is substantially transparent only to the vertically polarized component of the beam. The polarization-sensitive regions of the filter are created by conductors positioned in parallel arrays, with the conductors defining the second and third regions being substantially orthogonal to one another. By suitable dimensioning and spacing of these conductors, it is possible to create effective electro-optical filters with great discrimination in passing radiation with differing polarizations.
The aforementioned filter assembly is rotated synchronously with the antenna/mirror assembly--by mechanical coupling, or by means of slaved drive systems--so that the parallel conductor arrays always maintain the same attitude to imaginary horizontal and vertical generating lines in the surface of the mirror, independently of their instantaneous rotational position. In a preferred mode of development of the invention, this is accomplished by substantially centering a substantially circular, flat disk of a material displaying high transmissivity to microwave radiation on the conjoint axis of rotation of the antenna/mirror assembly and entraining the same into rotational motion synchronized therewith. A central, circular region of the disk is left without any imprint of any conductive material thereon, and forms the first, all-pass, region of the filter. A second region, in the form of a concentric annulus abutting on the first region, is imprinted with a set of parallel lines defined by a conductive material such as a metallic deposit or etched away conductive surface; while the third region is similarly defined, except that the filter lines are in an alignment substantially orthogonal to the array in the second region, and that the third region abuts the outer perimeter of the second region.
Receiving sensors--in the form of circularly polarized microwave horns--are positioned behind each of the three regions. Since the regions are concentric with the axis of rotation of the antenna assembly, the sensors may be in fixed positions behind the filter disk and may be of the conventional, circularly polarized kind, equally sensitive to radiation of any inherent direction of polarization.
In actual use, the sensor located behind the all-pass zone of the filter is used to scan for and detect a particular source. When a source of interest has been detected, the outputs from the sensors behind the vertically and horizontally polarized zones of the filter are sampled to obtain a set of three signal intensities from the three zones for comparison and processing.
The receiver behind the central, all-pass, region will be exposed to the full intensity--as expressed in microwave energy per unit surface area--of the incoming beam. The
to the, respectively, two outer regions will be exposed horizontally and vertically polarized components which make up the total signal.
By comparing the two filtered signals with the total signal, it is possible to determine the principal plane of polarization of the incoming beam; and with continued scanning to detect any variation in the relative intensity of the two components. Once the three signals, derived in the same manner and representing directly comparable signal strengths unaffected by any characteristic of the apparatus, itself--save in the actual strength of the total signal beam--are made available, many methods of analysis may suggest themselves to one skilled in the art of deciphering the information contained in a beam of microwave radiation.
DESCRIPTION OF THE DRAWING
The preferred embodiment of the invention, and variants thereof, will be described below with reference to the accompanying drawing, in which:
FIG. 1 is a diagram representing the principal elements of the receiver of the invention, for detecting and analyzing microwave radiation and for determining its dominant mode of linear polarization;
FIG. 1A is a diagrammatic representation corresponding to that of FIG. 1, except that the filter therein is composed of three regions of differing transmission character;
FIG. 2 is a schematic representation of the polarization-sensitive microwave receiver of the invention--integrated with a conventional receiver for radar signals--in elevation;
FIG. 3 is a planar view of a filter disk for discriminating between orthogonal polarization directions, as employed in the receiver of the invention;
FIG. 4 is an enlarged, partial section of the filter disk shown in FIG. 3;
FIG. 5 is an enlarged section taken along line 5--5 of FIG. 4;
FIG. 6 is an elevational view, in partial section, of a microwave receiver of the invention, including a radiation-permeable housing; and
FIG. 7 is a plan view of the filter disk and collector array associated with the embodiment of FIG. 6.
DETAILED DESCRIPTION
FIG. 1 is a diagrammatic representation of the principal components forming the polarization-sensitive microwave radiation receiver of the invention, including a horizontal, circular filter disk 57 mounted for rotation, in the sense of arrow "R", on a vertical axis of rotation A--A. The disk 57 comprises a thin membrane material that is substantially transparent to radiation in the microwave frequency band.
It should be noted that the terms "vertical" and "horizontal" in this context need not refer to gravitationally defined directions--merely to orthogonally oriented axes--albeit in the preferred mode of use of the invention the microwave radiation receiver is likely to be oriented to scan the horizon around a substantially vertical axis.
The filter disk is subdivided into concentric regions 62 and 63, each defined by a plurality of parallel conductors 46 attached to the disk 57. The sets of parallel conductors in the outer region 62 are orthogonal to the array of similar parallel conductors in the inner region 63.
Also mounted for rotation on the axis A--A is a flat mirror 55 so constructed that it acts as an electro-optical reflector for radiation in the microwave frequencies; suitably as a panel of polished metallic alloy. In the schematic embodiment of FIG. 1, the mirror 55 has been configured as a planar ellipse and is mounted at substantially 45 degrees with respect to a horizontal plane orthogonal to the axis of rotation A--A. Suitably, the vertical projection of the mirror 55 is greater than the circular outline of the filter disk 57, but is, at least, equal thereto.
The mirror 55 is synchronously driven--in the sense of the rotational arrow "R"--with the filter disk 57, so that a horizontally aligned minor axis B--B of the mirror 55 remains parallel, at all angular positions of rotation, with the array of parallel conductors defining one of the two filter regions, suitably inner region 63. Similarly, the array of conductors in the outer filter region 62 remains aligned with vertical elements in the mirror 55, including major axis C--C therein.
While the mirror 55 is shown in FIG. 1 as lying below filter disk 57 and being inclined at substantially 45 degrees so as to reflect a horizontally incident beam of radiation on its surface vertically through the filter disk, it is evident that the same effect can be attained by a kinematic inversion of these elements, so that the filter disk is below the mirror on the axis of rotation and the radiation is reflected downwardly therethrough.
As radiation originating on the horizon is reflected through the filter disk 57, vertically polarized components therein will tend to pass through the conductor array of region 62 with little attenuation. Similarly, horizontally polarized components of the incident microwave beam will readily pass through the region 63; the converse, in both regions, is not so and radiation with electrical field vectors parallel to the array of conductors will be greatly reflected and, therefore, attenuated by the two zones of the filter disk. Consequently, microwave receiving sensors 58 and 68--statically positioned above the filter regions 63 and 62, respectively--will be exposed to two orthogonally polarized components of the incoming beam.
Measuring the signal strengths collected, respectively, by the receivers 58 and 68 and comparing them will clearly indicate the relative polarization of the received signal. The ratio of the signal strengths to which the receivers 58 and 68 are exposed is independent of any angular differential between the location of the emitting source and the instantaneous view-angle of the mirror 55 as it scans the horizon, albeit the greatest signal magnitudes will be obtained when the mirror faces the emitter directly.
The receivers 58 and 68 are exposed to radiation which, although derived from a signal with a particular polarization plane, varies in direction of polarization as a result of the rotation of the mirror 55 and of the filter disk 57. Consequently it is important that these sensors be insensitive to such variation, and be selected from the class of microwave receivers (e.g. antennas) having circular polarization and low axial ratio.
FIG. 1A is a diagrammatic representation of a microwave receiver of the invention and is similar to the device shown in FIG. 1, except that the filter disk 57 is provided with three concentric regions of differring transmission character; a central region 64 with no obstacle to the transmission of any component in the signal reflected from the mirror 55, and regions 63 and 62 outboard of the central region 64 defined by arrays of grid lines as described with reference to FIG. 1.
The addition of a sensor 78--in the path of radiation passing through the central region 64--complements the filter 57, permitting the measurement of the total signal emanating from the source being analyzed, along with its constituent, mutually orthogonally polarized components.
FIG. 2 is a schematic representation of a preferred embodiment of the invention, incorporating an antenna 1, in the form of a parabolic reflector for electromagnetic radiation, and a planar mirror 55. The antenna 1 and the mirror 55 are joined by supports 16 and are mounted for rotation about a vertical axis A--A. The antenna 1 is positioned with its focal axis in a horizontal plane, while the mirror 55 is canted with respect to that plane at an angle of 45 degrees.
The mirror 55 is secured to the rear, non-focusing surface of the antenna 1 and is exposed to any incoming microwave beam during a complete rotation of the sensor assembly around the axis A--A.
Rotational movement for the antenna 1, and for mirror 55, is derived from a rotator 4, suitably in the form of an electric motor and gearbox combination. The rotator 4 impels a turntable 17 onto which the mechanically interconnected antenna 1 and mirror 55 are mounted, along with microwave feed device 2.
Incident electromagnetic radiation striking the focusing surface of the antenna 1 is collected by the feed 2, whose receiving portion is located at the geometric focus of the parabolic curve defining the surface of the antenna. The collected electromagnetic signal is transferred to an output port 15 via coaxial transmission lines 14, with a rotating coaxial joint 3 formed at a bearing 18 supporting the turntable 17.
A horizontally aligned circular filter disk 57, constructed from a dielectric material transparent to electromagnetic radiation, is secured to the mirror 55 by means of dielectric supports 6a, 6b. The disk is centered on the vertical axis A--A and rotates synchronously with the mirror 55, and, therefore, with the antenna 1.
A central, circular zone 64 in the face of disk 57 is left unobscured, so that electromagnetic radiation striking the mirror 55 in its central portion, and reflected upwardly toward the region 64, may pass without material diminution of its energy into a receiver 78, mounted in a stationary position above the region 64 and facing the mirror 55 therethrough. The receiver 78, and identical receivers 58 and 68--whose functions will be described below--are in the form of circularly polarized horns and are equally sensitive to all components of an incoming microwave beam, irrespective of the incident polarizations.
A vertically polarizing filter region 63, in the form of an annulus abutting the central zone 64, is defined by a series of parallel conductors imprinted onto the surface of the disk 57. These conductors are aligned with notional horizontal lines in the surface of the mirror 55, and serve to permit passage of horizontally polarized components of the incoming beam while blocking the transmission of the vertically polarized components. As a result of the definition of the region 63 in this manner, the receiver 58 which is positioned above the region 63 and facing downwardly toward the mirror 55 will only be collecting microwave energy which had been in the horizontally polarized components of the beam reflected by the mirror 55.
A horizontally polarizing filter region 62 is also provided in the disk 57, in an annular region outboard from the region 63 and extending toward the edge of the disk. The region 62 is similar in construction to the region 63, except that the conductors which define it are orthogonal to the similar conductors in the vertically polarizing filter region 63 and are parallel to vertical generating lines in surface of the mirror 55. The receiver 68--identical to the receivers 58 and 78 and similarly mounted in a stationary position above the filter disk, behind the region 62--is, consequently, exposed to the vertically polarized components, in the incoming radiation beam.
Due to the synchronization in the rotational motions of the mirror 55 and of the filter disk 57, the relative strengths of the three signals derived from the receivers 78, 58 and 68 do not vary with the changing angle of incidence of the received beam as the rotator 4 impels the detector assembly into its circulatory motion. Of course, the strength of the signal will be greatest when the mirror 55 squarely faces the point of origin of the incoming microwave beam.
The microwave energy captured by the receivers 78, 58, and 68 is suitably directed toward analytical instrumentation--capable of determining the relative strengths of the three signals--by means of waveguide transmission lines 9a, 9b and 9c. In a particular embodiment of the invention, a single analytical instrument--at its simplest a microwave diode coupled to a microammeter--can be used to read all three signal strengths, by the interposition of a single-pole, three-position switch 10 between the waveguides 9 and a single output transmission line 19.
FIG. 3 is a schematic plan view of the filter disk 57 shown in FIG. 1A. The disk, or its functional equivalents, may be constructed in several ways but it is foreseen that a preferred embodiment will involve a circular plate 57 of low loss, low dielectric strength material--Teflon or Mylar are suitable substrates--with conductive grids 46 to define regions 62 and 63 either printed or photoetched onto a surface of the plate or formed of wires or strips glued to it, or embedded into the plate in the case of a molded plastic disk. One alternate method of construction is to utilize air as the dielectric and to form the grids in space out of wires, either continuously bent or welded, or soldered, into the parallel arrays of regions 62 and 63.
The ability of the filter regions 62 and 63 to pass radiation polarized perpendicular to the conductor arrays is influenced by the geometrical properties of the conductors forming such grids. Both theoretical and experimental studies have indicated that it is preferable to provide a spacing--centerline to centerline of adjacent conductors--between grid lines equal to, or smaller (preferably by an order of magnitude) than, one-half of the wave length of the microwave radiation to be analyzed. Similar considerations lead to the desideratum that the spacing between adjacent conductors be much greater than their physical width--the dimension obstructing the passage of microwave radiation through the disk 57--preferably by an order of magnitude.
It is foreseen that the greatest utility of the instant invention will lie in analyzing incoming signals typically in the "K" and "A" bands--respectively occupying the 18 to 26 GHz and 26 to 40 GHz regions in the electromagnetic spectrum--with wave lengths ranging from 0.7 to 0.3 inch to a single-digit approximation). For application to such frequencies--generally referred to as millimeter waves--it is appropriate to utilize line widths ranging from approximately 0.025 inch to about 0.005 inch, with corresponding spacings from 0.100 to 0.030 inch. Typical dimensions are in the region of 0.040 inch in line spacing and 0.012 inch in conductor width.
FIG. 6 is an elevational view, in partial section, of a microwave signal receiver of the invention, designed to operate in two separate frequency bands within the electromagnetic spectrum. The device incorporates a principal microwave antenna 1--in the form of a partial paraboloid of revolution with a focal axis extending horizontally toward the horizon and a suitable collector or feed 2 for microwave energy located at the focus of the receiver. The antenna 1 and its collector 2 are mounted on a turntable 17 which is journalled for rotational movement in a bearing 18, with the collector being on adjustable mountings 22.
Rotation of the turntable. 17--and the components mounted thereon--is achieved by a gearmotor 4 powered from an electrical power supply cable 24. Microwave radiation received by the collector 2 is channelled towards instrumentation/display and analytical devices--not shown and not forming part of the instant invention--by means of a coaxial conductor 14 which passes through a rotary coaxial joint 3 within the gearmotor assembly 4.
A mounting plate 32 is supported partly by the rear, inactive, face of the antenna 1 and partly by a support bar 16 secured to the turntable 17. A flat mirror 55--suitably with a polished metallic surface--is secured to the mounting plate 32 which is tilted at 45 degrees from the horizontal reference plane.
A horizontal, circular filter disk 57 is attached--by means of supports 6a and 6b--to the mirror 55 and its mounting plate 32. The positioning of the filter disk 57 is such that its center coincides with the common rotational axis of the antenna 1 and the mirror 57. The filter disk 57 is divided into three concentric regions 64a, 63 and 62 --analogous to the regions 64, 63 and 62, respectively, of FIG. 3--which are not visible in the elevational view of FIG. 6, but shown in FIG. 7.
While the filter disk 57 is analogous to filter disk 57 in FIG. 3, it differs therefrom in that the central, circular region 64a of the disk is in the form of an orifice machined through the dielectric material of the disk. The adjacent, concentric regions 63 and 62 are formed by parallel conductors printed onto the surface of disk in mutually orthogonal arrays.
The entire rotating assembly--including the collector 2, the antenna 1, the mirror 55, the filter disk 57, and the various mechanical supporting elements interconnecting them with the turntable 17--is enclosed in a stationary housing constructed from a dielectric material, comprised of a circular base 131, a cylindrical shell 130, and cover 133 secured to the shell 130 at a flange 134.
A pair of microwave receiver horns, 108a and 128a, are mounted onto the inner surface of the cover 133 and project downwardly through disk orifice 64a and face the reflecting surface of the mirror 55. The two microwave receivers are of a circularly polarized construction and are equally sensitive to microwave radiation in all polarized states, except for opposite-sense circular polarization. The dimensionally smaller microphone horn 108A is optimally tuned for a higher frequency than the similar, but larger, microwave receiver 128a. Suitably, the receiver 108a is sensitive to the 26-40 GHz band, while the receiver 128a is sensitive in the 18-26 GHz band.
The outer region 62 of the filter disk is surmounted by receiver horns 108b/128b (not shown in FIG. 6 but shown in FIG. 7), while the intermediate region 63 is surmounted by receiver horns 108c/128c. These receivers are also supported by the cover 133 and are positioned with the lips of their sensing horns proximate to, but not touching, the moving surface of the filter disk 57.
The energy derived from an incident microwave beam reflected by the mirror 55 into the receivers 108 is conveyed through a network of wave guides and cavity switches--whose arrangement will be explained hereinbelow with reference to FIG. 7--to an output waveguide 119, terminating at an instrumentation flange 129. The signal is directed from the connection 129 to any desired measuring or analytical device for further processing.
FIG. 7 is a schematic plan view of the filter disk 57 as well as the components associated therewith and secured to the cover 133. The disk 57, as previously discussed, is divided into three concentric regions; a central orifice 64a; an inner annular region 63; and an outer annular region 62. The regions 63 and 62 are defined by arrays of identically dimensioned and spaced parallel conductors--as shown in portions of disk 57 in the illustration--with the respective arrays in mutually orthogonal alignments.
Each region of the filter disk is surmounted by two microwave receivers--in the form of circularly polarized horns which exhibit no preferential sensitivity to particular directions of polarization in the signal presented to them. For each region of the filter disk 57 there are two similar receivers provided which are sensitive to distinct frequency bands; receivers 108 respond to shorter wavelengths than receivers 128, which have larger physical dimensions.
The particular receivers, 108a and 128a, provided to receive microwave radiation aimed through the open central orifice 64a of the filter disk after reflection from the mirror 55 are placed so that they project into the opening of the central orifice 64a. The receivers associated with regions 63 and 62--108b and 128b above the inner annulus 63, and 108C and 128C above the outer annulus 62--are mounted with their entrance openings spaced from the upper surface of the disk 57 by a small distance for mechanical clearance.
As discussed above, the synchronous rotation of the disk 57 with the mirror 55 ensures that the receivers will at all times be exposed to, respectively, the horizontally and vertically polarized components of the incoming signal.
The microwave energy impinging on the several receivers 108 and 128 is channelled toward output lines 119 and 120 by means of waveguides--shown in the illustration but left unindexed--which are interrupted by switches 141, 142, 143 and 144. Each of the aforementioned switches is equivalent to a single-pole-double-throw electrical switching device and can be reset by remote control from one position to the other. The particular configuration of switches shown in FIG. 5 permits any one of the three receivers in each frequency band to be connected to each of the two output lines 119 and 120 at any given time. In the state illustrated, it is the higher frequency, K-band receiver 08A, in the unfiltered signal region 64a, which is connected to output line 119, while the A-band receiver 128A is connected to output line 120.
FIG. 7 also illustrates one method, in a modern microwave receiver, for measuring the signal strength collected by a particular sensor in the improved microwave receiver of the invention, by the interposition of a microwave diode 201--shown communicating with output line 120--between an ammeter 202, and an electrical load 203.
The configuration of switching elements illustrated in FIG. 7 permits rapid switching between specific receivers in the sensing array, but does not permit the parallel transmission of two or more signals to recording or analytical devices. It is contemplated that alternate arrangements for conveying the received signals may be employed and are encompassed in the scope of the invention; specific configurations may be readily defined by those skilled in the art, once exposed to the teachings herein. Similarly, it is contemplated that minor variations in the dimensions, arrangements or method of manufacture of the several components in the polarization-sensitive microwave receiver of the invention are deemed encompassed by the disclosure and description of the preferred embodiment hereinabove. | The invention relates to a receiver for microwave signals--either emitted by a body or reflected therefrom--capable of analyzing the polar distribution of the signal strength by measuring the strength of the incoming signal after it had been passed through a horizontal, polarizing filter disk with three distinct transmission regions. One region transmits the entire signal reflected from a planar mirror positioned substantially at 45 degrees to the horizon and rotated on a vertical axis; the second and third regions in the planar electro-optical filter are defined by parallel grid lines, formed by electrical conductors opaque to the reflected radiation and aligned in mutually orthogonal arrays in the two regions respectively, so that each grid alignment becomes transparent to one polarization of the radiation incident thereon. The filter is rotationally slaved to the reflecting mirror and the grid lines of one region are parallel to the horizon, as reflected onto the horizontal plane of the filter assembly, and admit the horizontally polarized component of the incoming signal; the grid lines of the other region admit the vertically polarized component. Comparison of the unmodified incoming signal with the horizontal and vertical components thereof permits the characterization of the emitting, or reflecting, antenna, or conductive body acting as an antenna, which is the source of the detected microwave energy. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to pending U.S. Patent Application Ser. No. 60/508,182 (Attorney Docket Number PC-P005V, filed Oct. 2, 2003 by Robert Schmidt, et al. and entitled “Shear Mechanism for Backpressure Relief in a Choke Valve.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus and method for providing relief to a hydraulic choke from exposure to excessive backpressure. More particularly, the present invention relates to pressure reducing valves and valve openings having shearable restraints.
[0004] 2. Description of the Related Art
[0005] The present invention is applicable to hydraulic choke valves, which are a subclass of pressure reducing valves. Choke type pressure reducing valves generally function by causing a portion of the potential energy of a pressurized fluid to be dissipated through turbulence when the pressurized fluid is passed through a restrictive orifice. Typically, the orifice of a choke valve is selectably variable through reciprocation of its valving member toward and away from the valve seat, so that a desired combination of flow and exit pressure may be obtained.
[0006] A choke valve is normally open and is designed for one-way flow. This construction differs from that of a relief valve, which is another type of one-way flow valve that is normally closed. The present invention is applicable to a choke valve that differs in construction from the most common arrangement of such valves in having its flow gate pressure-balanced. Because of the pressure balancing of the sealing plug, the actuating loads on the stem of the flow gate are considerably reduced compared to those of most choke valves of comparable capacity. However, the stem of the flow gate, which connects to the reciprocable control screw of the actuator used to reciprocate the flow gate for this type of choke, is not pressure balanced. The present invention has as its purpose the release of excessive backpressure induced axial loads on the flow gate stem in order to avoid overload of the stem or the actuator that is attached to the stem.
[0007] The concept of a shearable release as a means of opening a relief valve on a one-time basis prior to rebuilding of the valve is disclosed in Allen U.S. Pat. No. 2,304,491, where a common nail is used as a shear pin. The sealing plug of the Allen valve is directly restrained against reciprocably unseating by the nail.
[0008] West U.S. Pat. No. 4,587,987 discloses a relief valve very similar to that of Allen, but with an indirectly acting shear mechanism. West uses a four-bar linkage mechanism that has a shearable link interconnecting two of its arms. The shaft of the West sealing plug is restrained by abutting one bar of the linkage, where one end of that bar is held by the shearable link. When the link shears due to excessive reaction loads to the forces applied to the supporting bar by the valve plug, the plug unseats to release the pressure.
[0009] Risinger U.S. Pat. No. 4,359,094 discloses a relief valve that has multiple directly acting releases for its sealing valving members, wherein the valving members are held by shear screws or shear pins. This particular construction is made to be inserted into a well bore to control a flow bypass.
[0010] While the references above do show shear release means for opening relief valves that are closed, there is a need for a shear release means for pressure reducing valves that are either open or closed.
SUMMARY OF THE INVENTION
[0011] The invention contemplates a simple, easy means to release excessive backpressure acting on the throttling and sealing member of a pressure reducing valve before overloading either the stem of the valve or its actuator. The shearable means of the present invention is applicable to pressure reducing valves that operate through reciprocation of their valving members and is useable with a wide variety of valve actuator types.
[0012] One aspect of the present invention is a choke valve comprising: a body having an axial through hole and a radial entry port; a valve seat coaxially housed in the body axial through hole on a first side of said radial entry port; a pressure balanced valving member axially reciprocable within the body axial through hole between a first sealing position bearing against said valve seat and a second position spaced away from said seat; actuator means for applying reciprocatory motion to the pressure balanced valving member through an intermediate structure; and a shearable mechanism interconnecting the actuator means and the valving member, wherein the shearable mechanism is responsive to fluid pressure in excess of a predetermined value.
[0013] Another aspect of the present invention is a choke valve comprising: a body having an axial through hole passing from a first side of the body to a second side of the body, an outlet passageway coaxially aligned with the through hole and positioned at the first side of the body, and a radial inlet port intersecting the through hole between the first and second sides of the body; a valve seat coaxially housed in the through hole between the inlet port and the outlet passageway; a valving member axially reciprocable within the through hole between a first position bearing against the valve seat and a second open position spaced away from the valve seat; an actuator attached to the second side of the body for reciprocably moving the valving member between the first position and the second position; and a shearable mechanism having a stem interconnecting the actuator and the valving member; whereby whenever the shearable mechanism is subjected to fluid pressure in excess of a predetermined value from the outlet passageway the shearable mechanism will shear and the stem and the valving member will move away from the valve seat.
[0014] Yet another aspect of the present invention is a choke valve comprising: a body having an axial through hole passing from a first side of the body to a second side of the body, an outlet passageway coaxially aligned with the through hole and positioned at the first side of the body, and a radial inlet port intersecting the through hole between the first and second sides of the body; a valve seat coaxially housed in the through hole between the inlet port and the outlet passageway; a pressure balanced valving member axially reciprocable within the through hole between a first position bearing against the valve seat and a second open position spaced away from the valve seat; an actuator attached to the second side of the body, the actuator having an axially reciprocating actuator shank for reciprocably moving the valving member between the first position and the second position; and a shearable mechanism interconnecting the actuator shank and the valving member, the shearable mechanism comprising a stem, a first end of the stem positioned in a socket in one end of the actuator shank and a second end of the stem mounted to the valving member, and a shear pin passing through the stem proximal to first end of the stem and passing through a wall of the socket in the actuator shank when the first end of the stem is located in the socket at less than a full depth of the socket; whereby whenever the valving member is subjected to a fluid pressure in excess of a predetermined value from the outlet passageway the shear pin will shear and the stem will move further into the socket in the actuator shank thereby moving the valving member away from the valve seat.
[0015] Still yet another aspect of the present invention is a choke valve comprising: a body having an axial through hole passing from a first side of the body to a second side of the body, an outlet passageway coaxially aligned with the through hole and positioned at the first side of the body, and a radial inlet port intersecting the through hole between the first and second sides of the body; a valve seat coaxially housed in the through hole between the inlet port and the outlet passageway; a pressure balanced valving member axially reciprocable within the through hole between a first position bearing against the valve seat and a second open position spaced away from the valve seat; an actuator attached to the second side of the body, the actuator having an axially reciprocating actuator shank for reciprocably moving the valving member between the first position and the second position; and a shearable mechanism interconnecting the actuator shank and the valving member, the shearable mechanism comprising a stem, a first end of the stem positioned in a socket in one end of the actuator shank at less than a full depth of the socket and a second end of the stem mounted to the valving member, a pair of split shear ring halves mounted in a mounting groove in the stem proximal to the first end of the stem, and a shear ring keeper device mounted over the shear ring halves to maintain the shear ring halves in position; whereby whenever the shearable mechanism is subjected to a fluid pressure in excess of a predetermined value from the outlet passageway the shear ring halves will shear and the stem will move further into the socket in the actuator shank thereby moving the valving member away from the valve seat.
[0016] The foregoing has outlined rather broadly several aspects of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or redesigning the structures for carrying out the same purposes as the invention. It should be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0018] FIG. 1 is an oblique view of a hydraulic choke valve with its actuator, where the choke meters flow from a high pressure annular region around the axially reciprocable choke throttling member into a low pressure exit channel coaxial with the throttling member;
[0019] FIG. 2 is an axial view of the choke and actuator of FIG. 1 from the actuator side of the choke with the lid of the actuator removed;
[0020] FIG. 3 is a longitudinal sectional view of the choke and actuator taken along the section line 3 - 3 of FIG. 2 ;
[0021] FIG. 4 is an enlarged view of the portion of FIG. 3 showing the throttling member and its connection to both the reciprocable control screw of the actuator and the other components of the choke valve;
[0022] FIG. 5 is an oblique exploded view of the throttling member, the operating shaft, the reciprocable control screw, and their interconnection means;
[0023] FIG. 6 is a longitudinal sectional view of the throttling member assembly with the shearable overpressure protection mechanism intact;
[0024] FIG. 7 is a longitudinal sectional view, corresponding to FIG. 6 , of the throttling member assembly with the shearable overpressure protection mechanism sheared; and
[0025] FIG. 8 is a longitudinal cross-sectional view of the choke valve and reciprocable actuator control screw corresponding to FIG. 3 , but with the shearable overpressure protection mechanism sheared.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The present invention provides a shear release mechanism for releasing excessive backpressure acting on the throttling and sealing member of a pressure reducing valve before overloading either the stem of the valve or its actuator. This shear release mechanism operates through the reciprocation of the valving member and is applicable in a wide variety of valve actuator types.
[0027] Referring now to the drawings, and initially to FIG. 1 , it is pointed out that like reference characters designate like or similar parts throughout the drawings. The Figures, or drawings, are not intended to be to scale. For example, purely for the sake of greater clarity in the drawings, wall thickness and spacing are not dimensioned as they actually exist in the assembled embodiment.
[0028] FIG. 1 shows a partial longitudinal section of one embodiment of a hydraulic choke valve of the present invention. Although the materials of construction of the choke valve and its actuator may vary, typically they are constructed of a high strength low alloy steel, mild steel, or, in the case of O-rings and other elastomeric seals, Viton™ or nitrile rubber.
[0029] FIGS. 1 to 3 illustrate an assembled hydraulic choke valve system 10 consisting of a hydraulic choke valve 11 and an electrically or manually powered actuator 100 . Herein, the term “hydraulic choke” is taken to refer to the fact that the device is used with a variety of fluids, such as drilling mud, salt water, oil, gas, and other chemicals which may be injected into a well. “Hydraulic” does not herein refer to the choke actuation means.
[0030] The body 12 of the hydraulic choke valve 11 is a heavy walled steel right rectangular prism with an axial passage 25 extending completely through body 12 . The body 12 has a centrally positioned heavy walled projecting central cylindrical neck outlet branch 13 containing coaxially positioned axial passage 25 extending downwardly through neck 13 . The flow entry for the choke is inlet port 19 , and the flow exit is the righthand end of axial passage 25 , as shown in FIG. 3 .
[0031] Concentric transverse outlet flange 14 is positioned at the outer end of the outlet branch 13 . Body 12 also has a cylindrical actuator mounting neck 17 extending outwardly concentrically with the outlet neck 13 and the axial passage 25 , but on the opposed side of the body from the outlet neck. The outer end of actuator mounting neck 17 has concentric external male retention threads 18 by which most of the internal components of the valve may be retained.
[0032] Both the inlet and outlet flow passages 19 and 25 , respectively, are provided with concentric mounting grooves 21 and 16 for metal ring gasket seals (not shown) and concentric hole circles 20 and 15 for the mounting of the choke to connecting piping by means of threaded studs and nuts (not shown). The outlet flow passage has a terminal flange. The bolted and ring gasketed inlet and outlet connections are mateable with standard American Petroleum Institute (API) flange connections typically used for high pressures in the oilfield.
[0033] FIGS. 3 and 4 illustrate the internal arrangements of the choke 11 . Inlet flow passage 19 into body 12 is radial to the axis of the through axial passage 25 which extends from the actuator end to the outlet end of the body. Axial passage 25 has multiple coaxial bores along its length from the actuator end to the outlet end, with a coaxial enlarged counterbored annular, approximately cylindrical inlet distribution chamber 24 centrally located in body 12 . Entry chamber 25 is radially intersected by inlet flow passage 19 . The actuator end of axial passage has an outwardly facing transverse guide stop shoulder 26 . On the outlet side of the axial passage 25 just below inlet distribution chamber 24 is a transverse seat stop shoulder 27 . The bore of the outlet side of the axial passage 25 is reduced below the seat stop shoulder 27 , but is again enlarged adjacent the outlet end at transverse liner stop shoulder 28 .
[0034] Mounted in the large bore of passage 25 of the choke body 12 and abutting seat stop shoulder 27 on the outlet end of distribution chamber 24 is right circular annular cylindrical choke seat 32 . The seat 32 is provided with a pair of external male O-rings 33 . Outlet liner 34 is a thin-walled right circular cylindrical tube having a short exterior upset portion at its outlet end joined to the rest of the liner tube by an external transverse shoulder. The outlet liner 34 is inserted with a close slip fit into the outlet bore of the axial passage 25 to have its inner end abut against the outer end of seat 32 and its intermediate transverse shoulder abut against shoulder 28 .
[0035] The flow passage from the cavity 25 to the choke outlet is restricted by choke gate 40 . Choke gate 40 has an approximately right circular cylindrical shape with an axial through hole 41 having a counterbored enlargement on each end of the through hole. The end portions of the choke gate exterior cylindrical surface have short reduced diameter sections with conical transitions 42 to the central outer cylinder. The reduced diameter exterior end sections are a slip fit to the bore of seat 32 . The conical transitions 42 serve as sealing faces for the choke gate 40 and are able to seal against the interior portion of the adjacent transverse upper end of the seat 32 . Choke gate 40 is symmetrical about its transverse horizontal midplane, so that it may be inverted and a new sealing face 42 used when the first becomes leaky. Choke gate 40 has one or more internal flow passages 43 parallel to but offset from the longitudinal axis and connecting from one side to the other in order that it will not fluid lock and will be exposed to balanced opening forces when it is fully or nearly closed.
[0036] FIGS. 4 through 6 illustrate the components of the shearable actuator subassembly 44 . The subassembly shown in FIG. 5 consists of a stem 45 , a shear pin 49 , two split shear ring halves 52 , a shear ring keeper nut 76 , an axially reciprocable actuator screw 130 , and set screws 78 . In actual practice, either the shear pin 49 or the split shear ring halves are sufficient to provide a shear mechanism for backpressure relief in the choke valve, although both the shear pin and the split shear ring halves are illustrated in FIGS. 4 to 6 . The shearable actuator subassembly 44 using only one of the shearable components (i.e., either the shear pin or the split shear ring) can readily be made from the drawings and description herein by one skilled in the art.
[0037] Choke gate 40 is located on stem 45 , which is piloted into the upper counterbored pocket of the gate through hole 41 , and attached thereto by means of Allen screw 50 that extends through axial through hole 41 in the choke gate.
[0038] Stem 45 is a stepped cylindrical rod extending upwardly towards linear actuator 100 . The enlarged choke gate end of stem 45 is centrally drilled and tapped to threadedly engage with screw 50 for retaining the stem 45 and the choke gate 40 together. The shank 46 of stem 45 on its upper actuator end has an annular male groove 47 of rectangular cross-section and, adjacent the transverse end of the stem, a diametrical through hole 48 for mounting a closely fitting cylindrical shear pin 49 . The shear pin 49 , as illustrate in FIGS. 4 and 6 , is not only used as part of a shearable mechanism in the shearable actuator subassembly 44 , but the shear pin also serves as an antirotational device to keep the stem 45 and the choke gate 40 from rotating.
[0039] The portions of the choke exposed to high velocity flow (such as the gate 40 , the seat 32 , the outlet liner 34 , and possibly the gate guide 55 ) will typically be constructed of sintered tungsten carbide, a ceramic material, or will be hardfaced with a suitable wear resistant material, such as Stellite 3™.
[0040] The two split shear ring halves 52 are each 180° or slightly less than 180° segments of a right circular cylindrical ring which closely fits into annular male shear ring mounting groove 47 of stem 45 . The split ring halves 52 extend radially outwardly by approximately the depth of their mounting groove 47 . The shear ring is in halves so that it can be installed and removed readily from groove 47 .
[0041] Gate guide 55 , also referred to as an operator nose, is a thin walled cylindrical tubular structure with a short enlarged cylindrical upper actuator end joined to the main body and having a downwardly facing intermediate exterior transverse shoulder at that transition in outer diameters. The lower exterior end of the gate guide 55 is also slightly reduced in diameter adjacent the inlet distribution chamber 24 of the choke body 12 . The central external cylindrical section of gate guide 55 has multiple male O-ring grooves on its exterior at approximately mid length containing O-rings 60 which seal between the exterior of guide 55 and the upper bore of axial passage 25 of the choke body 12 . The main bore through gate guide 55 is slightly enlarged at approximately midlength. The lower interior cylindrical face of gate guide 55 has multiple female O-ring grooves containing O-rings 61 that seal between the gate guide and the exterior cylindrical surface of the choke gate 40 . At approximately one fourth of the length of gate guide 55 down from its upper actuator end, a thick interior transverse bulkhead 56 with a coaxial through hole 57 mounts multiple chevron seals 63 in a counterbore on the upper side of the through hole. The chevron seals 63 are oriented to prevent the escape of internal pressure in the annular gap between gate guide 55 and stem 45 . Stem 45 is journaled with a close fit in the central through hole 57 of guide 55 . Near the upper end of gate guide 55 are located a pair of diametrically opposed drilled and tapped holes which contain inwardly projecting half dog set screws 64 .
[0042] The rear section 66 of the operator nose is a heavy walled cylindrical tube with a thick transverse diaphragm having a through hole on its lower end. The inner diameter of the operator nose's rear section through hole provides a close slip fit to the stem 45 . At the lower end of the rear section 66 , the through hole has a short cylindrical counterbore 68 . The outer diameter of rear section 66 is reduced at a transverse shoulder near its lower end so that the lower end of the rear section 66 can enter the upper section of the bore of the gate guide 55 and the external shoulder abut the upper transverse end of the gate guide. Diametrically opposed detent holes 69 are match drilled through the drilled and tapped set screw holes of the gate guide 55 at assembly of the gate guide and the rear section 66 so that set screws 64 can retain the pieces in their desired abutted position. The upper transverse end of the rear section 66 projects slightly above the upper end of neck 17 of choke body 12 . The upper interior bore of the rear section 66 has female thread 67 for connection with the actuator mounting hub 104 of actuator 100 . A radial set screw hole 70 penetrates the wall of the rear section 66 at approximately midlength so that the threaded connection of the rear section and the actuator mounting hub 104 can be locked with set screw 71 .
[0043] A short annular right circular cylindrical ring with a reduced outer diameter tip on its downward side serves as a seal contactor 72 for the seals 63 . The reduced outer diameter of seal contactor 72 is a close slip fit to the seal housing counterbore of gate guide 55 . The bore of seal contactor 72 is a close fit to the stem 45 , and the transverse lower tip of the seal contactor bears on the heel of the uppermost of the stack of seals 63 . Multiple through vent holes offset from and parallel to the axis of the seal contactor 72 aid in the avoidance of fluid lock in the seal cavity.
[0044] Shear ring keeper nut 76 is a thick walled right circular cylindrical annular ring with a transverse diaphragm 77 having a coaxial through hole at its lower end. The through hole has a slip fit with the shank 46 of stem 45 . The upper bore of shear ring keeper nut 76 is threaded for connecting with the reciprocable actuator screw 130 of the actuator 100 . Adjacent its upper end, shear ring keeper nut 76 has a pair of diametrically opposed drilled and tapped holes which mount set screws 78 for locking the threaded connection of nut 76 to the screw 130 . Closer to the diaphragm 77 at the lower end of nut 76 , a pair of diametrically opposed holes is aligned with the axis of shear pin hole 48 of stem 45 when the shearable actuator assembly is made up. This pair of holes provides access to the shear pin 49 .
[0045] Hollow keeper nut 97 is threadedly attached to the male threads 18 of the externally threaded actuator mounting neck 17 of the choke body 12 and serves to retain the internal components of the choke, which include the choke gate 40 and the stem 45 , gate guide 55 , rear section 66 , seal contactor 72 , and seals 63 . The keeper nut 97 has a heavy walled right circular cylindrical annular body open at its lower end and with a female thread 99 threadedly comated to the male thread 18 on the upper mounting neck 17 of choke body 12 on its interior. At the upper end of keeper nut 97 is a transverse diaphragm 98 with a central through hole which provides a shoulder for engaging the upper transverse end of the rear section 66 .
[0046] The actuator 100 is not described in detail, since such actuators are in very broad use and are well known to those skilled in the art. Only a general description of one type of actuator is given here. The actuator 100 may be manual or either electrically, hydraulically, or pneumatically operated. In most cases, the actuator 100 will be powered and also provided with a separate manual override, as is shown in FIGS. 1 and 2 . Referring to FIG. 1 , the actuator box 101 of the actuator is a rectangular prismatic hollow box with a removable lid and exterior mounting bosses to which the actuator drive 102 and the actuator mounting hub 104 are mounted by screws. Mounting hub 104 is a transverse circular flange having a bolt hole circle for connection to the box 101 and with a coaxial right circular cylindrical neck extending downwardly and a coaxial through hole. Male mounting hub neck threads 105 are on the lower exterior end of the neck of mounting hub 104 and serve to attach the actuator to the choke 11 by being threadedly engaged into the female threads 67 of the rear section 66 . Set screw 71 restrains that connection.
[0047] The actuator drive 102 is a rotary device powered by an electric power line or hydraulic or pneumatic hoses (not shown). Coaxial with and on the opposed side of the box 101 from the actuator drive 102 is a selectably manually engagable handwheel 103 which is normally declutched, but can be used to operate the internal worm gear drive of the actuator 100 if the actuator drive malfunctions. The handwheel shaft 108 is supported in a bearing (not shown) in the external boss projecting from the actuator body 101 on the handwheel side. Internal to the body 101 is the worm gear set mount 112 in which are a mounted worm 111 and a screw drive worm gear 117 driven by the driven shaft 110 common to the drive shaft 106 and the handwheel shaft 108 . Shaft 110 is directly attached to the worm 111 . Both gears are supported on bearings in the mount 112 and prevented from shifting axially by their mountings therein. Worm gear 117 is driven on its outer periphery by worm 111 . Coaxial with the worm gear peripheral gear and its journaling ends is the interior bore of the worm gear 117 , wherein female acme drive thread 118 is located. The worm gear drive is used in order to provide a torque multiplication and speed reduction for the drive and also to resist backdriving of the actuator by thrusts on the actuator shaft. An antirotation flange 115 is mounted on top of the worm gear set mount 112 in a position coaxial with the worm gear 117 . Antirotation flange 115 consists of a transverse flange with mounting holes and a coaxial upwardly projecting right circular cylindrical tubular neck which has an internal integral rectangular section antirotation key 116 extending radially into the through bore of the antirotation flange.
[0048] Axially reciprocable actuator screw 130 provides the output for the actuator. Actuator screw 130 has a male acme thread 131 in its midsection and a reduced diameter coaxial lower shank 132 extending downwardly. The region of the lower shank 132 adjacent to the acme thread 131 of the actuator screw has a male thread 133 that may be threadedly engaged with the female upwardly-looking threads of the shear ring keeper 76 . Lower shank 132 fits within the bore of the shear ring keeper 76 . The lower shank 132 has a downwardly opening coaxial bore lower shank socket 134 which is a close sliding fit to the shank 46 of stem 45 . A transverse shoulder connects the main bore of socket 134 with a short enlarged counterbore which is a close fit to the outside of the shear ring halves 52 when they are mounted in the shear ring groove 47 of the stem 45 . A diametrical shear pin hole 135 sized to accommodate shear pin 49 extends through lower shank 132 of actuator screw 130 in a position that is coaxial with the corresponding shear pin hole 48 of stem 45 when the shearable actuator subassembly 44 is assembled together. Reduced diameter cylindrical upper shank 136 is located on the upper end adjoining acme thread 131 of actuator screw thread 130 . An upwardly opening longitudinal antirotation keyway 137 is cut into the length of upper shank 136 . Keyway 137 is sized to slidingly engage the antirotation key 116 of the antirotation flange 115 so that actuator screw 130 cannot be rotated.
OPERATION OF THE INVENTION
[0049] The choke 11 of the hydraulic choke valve assembly 10 shown in the present invention is operated by nonrotating linear up and down stroking of the actuator screw 130 of the actuator 100 shown herein. The choke gate 40 , supported and operated by the shearable actuator subassembly 44 , is guided in its reciprocation by the gate guide 55 . The chevron seals 63 are held in place so that they can seal to the stem 45 by the rear section 66 and the seal contactor 72 , which are themselves held in place by keeper nut 97 engaging the threads 18 of the actuator mounting neck 17 . Likewise, the gate guide 55 is held in place axially by being abutted by both the guide stop shoulder 26 and the operator nose's rear section 66 . The actuator 100 is rigidly mounted to the choke 11 by the threads 105 of the actuator mounting hub 104 engaging the female threads 67 of the rear section 66 .
[0050] The antirotation flange 115 of the actuator restrains the axially reciprocable actuator screw 130 against rotation when the drive shaft 110 and its attached worm 111 rotate worm gear 117 . The worm gear 117 is itself held against axial translation by its fixity against linear motion by its mounting in the worm gear set mount 112 of the actuator 100 . Accordingly, the actuator screw 130 is caused to reciprocate by appropriate rotation of the worm gear 117 .
[0051] The choke valve 11 has its choke gate 40 pressure balanced because of the communication of fluid pressure from one end of the choke gate to the other through the internal flow passages 43 of the gate. This pressure balancing of the gate permits the pressure on the stem 45 of the choke to be reduced and, accordingly, the pressure loads typically expected on the actuator through the stem will be correspondingly reduced. This is because the pressure in the outlet of the choke acts only on the cross-sectional area of the shank 46 of the stem 45 ; the pressure load on the actuator is the product of the outlet pressure and the shank area. The consequence of this is that smaller actuators can be used to control a given flow condition, when compared to the conventional unbalanced chokes.
[0052] Normally, pressures in the outlet branch of the choke 11 (i.e., through the bores of the choke seat 32 and the outlet liner 34 ) are much lower than in the inlet port 19 . When the choke is in good condition, it will reliably seal when the sealing face 42 of the gate 40 is pressed against the seat 32 . Since the outlet side of the choke is typically vented, the pressure on the outlet line would thus be very low in such a case. Even when the choke is opened and exposed to a high inlet pressure, it is typically operated in a manner such that a very, high pressure drop is taken across the flow orifice opened between the gate 40 and the seat 32 , with the result that the outlet pressure still would be low. Thus, in the normal situation, the axial loads transmitted to the stem 45 and hence to the actuator 100 through the connection of the stem to the actuator screw 130 are low.
[0053] In the event of a stoppage in the outlet line or some other flow upset, such as a downstream water hammer or the opening of a valve at the wrong time, very high pressures can be produced in the outlet line of the choke 11 . In such an instance, a high pressure induced axial compression load is translated to the stem 45 of the choke. This high load has the potential to damage the stem 45 , the actuator 100 , or both the stem and actuator. However, referring to FIGS. 5 through 6 , it is apparent that the compressive reaction load path from the stem 45 to the actuator screw 130 has to pass through the split shear rings 52 and the shear pin 49 . Thus, the shear areas and shear strengths of the shear pin 49 and the split shear rings 52 are preselected to structurally fail when exposed to a predetermined, safe axial load through shear. The resultant shear failure will cause the shear pin 49 and the split ring halves 52 to separate on the cylindrical interface between the shank 46 of the stem 45 and the lower shank socket 134 of the actuator screw 130 , as shown in FIG. 7 . The shear pin will separate into residual segments 49 a and 49 b , while the split shear rings will separate into segments 52 a and 52 b , as seen in FIG. 7 . After the failure of these weak link members, the choke gate 40 and the attached stem 45 both will shift upwardly toward the actuator 100 by telescoping of the stem into the lower shank socket 134 under the action of the pressure force on the stem. When this has happened, the orifice between the choke gate 40 and the seat 32 will be fully opened, as shown in FIG. 8 , thereby permitting the outlet side pressure to vent upstream if the pressure comes from downstream. The venting in such a case, due to careful selection of the failure properties of the shearing members 49 and 52 , should prevent excessive loads from occurring to either the actuator or the stem. If the pressure on the inlet side of the choke 11 is already high when the backpressure becomes elevated, the stem 45 is still protected by virtue of its effective unsupported length being shortened due to telescoping into the actuator screw 130 . The buckling tendencies of an axially compressed member generally are much reduced when its unsupported length is reduced. The actuator 100 and the upper group of choke internal parts 40 through 97 readily can be removed from the choke body 12 by disconnecting keeper nut 97 . This permits easy access to the choke internal parts so that the shear pin 49 and the split shear rings 52 simply can be replaced and the choke reassembled after the backpressure condition is eliminated.
[0054] The present invention permits the use of a smaller, less expensive actuator for a choke while at the same time greatly reducing the likelihood of failure of the choke stem or the actuator due to an incident of high backpressure on the choke outlet line. Two separate modes of equipment risk reduction result from the use of a shearable, telescoping link between the actuator and the stem supporting the pressure balanced choke gate. The first is the reduction of the unsupported length of the stem, whereby its tendency to buckle and overstress is greatly reduced. The second advantage is the venting of pressure upstream so that the high backpressure is released prior to damaging the choke assembly. This second advantage requires that the upstream pressure be relatively low when the high backpressure occurs. This and other advantages will be readily apparent to those familiar with the art.
[0055] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. | The present invention relates to a mechanism for preventing damage to the actuator of a hydraulic choke valve in the event of excessive backpressure on the outlet of the choke. The backpressure relief device is applicable to a choke valve which meters flow from a high pressure annular region around the axially reciprocable choke throttling member into a low pressure exit channel coaxial with the throttling member. In particular, a shearable means is used to connect the reciprocable control shank of the actuator to the throttling valve member of the choke valve. In the event of excessive pressure on the exit channel of the choke valve, the shearable means will shear, thereby fully opening the valve and permitting the excessive pressure to escape. The shearable means is readily replaced so that the valve easily can be put back into operating condition. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Patent Application No. PCT/CN2009/000246 with an international filing date of Mar. 9, 2009, designating the United States, and further claims priority benefits to Chinese Patent Application No. 200810201897.9 filed Oct. 29, 2008. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a medical nuclear contrast medium, and more particularly to a nitroimidazole-amino acid hypoxia contrast medium, a precursor, preparation method, and use thereof.
2. Description of the Related Art
Tumors have become one of the major killers of human health. Malignant tumors usually need to be surgically removed, or be removed using chemotherapy or radiation. These therapies, however, have very negative effect on patients, since not only tumor cells will be killed, but also normal cells will be damaged to various degrees, which leads to mental affliction as well as decline in physical strength of the patients. Therefore, an early detection and diagnosis of tumors are very much desired, so that tumor cells can be eradicated at an early stage and the patients can obtain a new life. Scientists have already discovered that malignant tumors contain hypoxic cells and it is possible to detect tumor cells by testing cellular oxygen level. It has been reported that oxygen electrodes can be used to test cellular oxygen level. However, this method is very limited in terms of in vivo application. In recent years, nuclear technology has been applied in medical field for the detection of hypoxic tumor cells. Nuclear technology deploys hypoxia imaging technique which enables it to be detained in hypoxic cells, and then detects the oxygen level through imaging technology, which leads to the detection and diagnosis of malignant tumors. Nitroimidazole and their derivatives are used as radiation sensitizers. Their metabolisms inside cells are determined by the available cellular oxygen. Therefore, hypoxic cells can be imaged by labeling these compounds with radioactive nuclides. Nowadays, nuclear technology has become a focus of radiology medicine and hypoxia cellular imaging has also received a lot of attention. For example, 18 FMISO, 99mm Tc-HL91 and other compounds have been frequently used in clinic imaging research as hypoxia contrast medium. However, they possess a lot of drawbacks such as low absolute intake value by tumor cells, long imaging time and high cost, etc. As a result, a more effective tumor contrast medium is still in need.
SUMMARY OF THE INVENTION
In view of the above-described problems, it is one objective of the invention to provide a nitroimidazole or a derivative thereof as a contrast medium targeting hypoxia cells.
It is another objective of the invention to provide a precursor of the contrast medium.
It is still another objective of the invention to provide a method for preparation of the precursor.
To achieve the above objectives, in accordance with one embodiment of the invention, there is provided a hypoxia contrast medium comprising nitroimidazole-amino acid chelate with a positively charged radioactive nuclide.
In accordance with another embodiment of the invention, there is provided a precursor of the nitroimidazole-amino acid compound (Formula 1),
comprising 1-(2-aminoethyl)-2 methyl-5-nitroimidazole or its derivatives connected with amino acids via chemical bonds.
The compound is served as a Chelan and is chelate with a nuclide to form a chelate complex and thus nuclear hypoxia contrast medium.
The nitroimidazole component of the compound targets hypoxic cells. The mechanism is that the R—NO 2 group is converted into R—NH 2 by Nitroreductase in hypoxic cells ( FIG. 1 ). Due to this bio-chemical reaction which is specific to hypoxic cells, the contrast medium of the current invention can be accumulated inside hypoxic cells. The contrast medium molecule of the current invention contains amino acid component, which possesses negatively charged R—COO − and —NH 2 groups. These groups can easily chelate positively charged radioactive nuclide and enables the whole molecule to be radioactive and thus tumors can be imaged by tracing radioactive nuclides.
There are two mechanisms of the tumor-targeting effect of the contrast medium of the current invention: 1). the rapid growth of tumor cells results in a lack of blood and oxygen supply to the central part of the tumor, and this leads to the formation of hypoxic and necrotic tissues. Due to the presence of the hypoxic tissue in the tumor, the contrast medium of the current invention can be used to image tumors. 2). Normal cells can synthesize asparagine which is essential for the growth of the cells. Tumor cells do not have this function, and has to rely on eternal supply of asparagines. The contrast medium of the current invention contains asparagines, and therefore can be used in tumor imaging.
The contrast medium of the current invention is a novel hypoxic-cell-targeting contrast medium. This contrast medium can chelate radioactive nuclides generally used clinically, such as 99m Tc, 113 In. After being injected into the human body, the contrast medium is specifically accumulated in hypoxia cells and tissues. Through SPECT (ECT) or γ-camera, hypoxia lesions can be traced and can be clearly imaged after data date processing on computers. Hence, the doctors can accurately diagnose the location, size, and the degree of malignancy of the hypoxia tissues. Medically, the hypoxia lesions mentioned above refer to certain tissues in human body which are lacking supply of oxygen and blood so that the cells and the tissues are dead (such as cerebral thrombosis, tumors, and other thrombosis).
The derivatives of the nitroimidazole of the invention have a formula as shown in Formula 2:
The amino acids in the contrast medium of the current invention are aspartic acid (Asp), glutamic acid (Glu), asparagines (Asn), glutamine (Gln), glycine (Gly), serine (Ser), lysine (Lys), cysteine (Cys), cystine ((Cys) 2 ), or arginine (Arg), and they are D- or L-amino acids.
The amino acids connected with the nitroimidazole or their derivatives are 1 to 15 amino acids, and they are concatenated to one another as shown in Formula 3,
or connected to another in parallel as shown in Formula 4,
or connected to one another both in an concatenated way and in parallel as shown in Formula 5,
wherein the compound contains only one kind of amino acid connected in a way as shown in Formula 6,
or two kinds of amino acids cross connected to one another as shown in Formula 7,
or any kind of amino acids arranged in a random way as shown in Formula 8.
When the amino acid is aspartic acid or glutamic acid, the amino acid is connected with the nitroimidazole or the derivative of the nitroimidazole or with another amino acid through α carbon, or through β or γ carbon as shown in Formula 9.
The radioactive nuclides used in the contrast medium of the current invention is Tc 99m , In 113m , In 111m , I 131 , P 32 , Hg 203 , Ga 67 , Ga 68 , Sr 85 , Cr 51 , Xe 133 , TI 201 , Kr 81m , Rb 86 , Rb 86 , or Cu 62 .
The contrast medium is the compound in Formula 10,
wherein the radioactive nuclide is chelate inside a single molecule, or the contrast medium is the compound in Formula 11,
wherein the radioactive nuclide is chelate between two molecules.
Still in accordance with one embodiment of the invention, there provided is a method for preparation of the precursor of the nitroimidazole-amino acid nuclear hypoxia contrast medium.
The amino group (—NH 2 —) of 1-(2-aminoethyl)-2 methyl-5-nitroimidazole is reacted with the carboxyl group of L-aspartic acid, a H 2 O molecule is released and an amide group is formed and the reaction product is 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole (FW=285) (Formula 12),
and thus the contrast medium of the current invention is formed.
The process is described as Reaction 1.
A. Synthesis of Compound 1: (1-[2-(2-(isobutylamino)-4-benzyl-L-aspartic ester)acylamideethyl]-2 methyl-5-nitroimidazole
3-30 mmol 2-(isobutylamino)-4-benzyl-L-asparticester is dissolved 50-500 mL dry dichloromethane solution. 3-30 mmol triethylamine, 3-30 mmol 1-(2-aminoethyl)-2 methyl-5-nitroimidazole and 3-30 mmol phosphoryl cyanide are added sequentially at room temperature into the dichloromethane solution. The solution is stirred simultaneously. The reaction mixture is washed with 100-120 mL water and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 4:1. The obtained product is (1-[2-(2-(isobutylamino)-4-benzyl-L-aspartic ester)acylamideethyl]-2 methyl-5-nitroimidazole.
B. Synthesis of Compound 2: (1-[2-(2-(isobutylamino)-L-aspartic acid)acylamideethyl]-2 methyl-5-nitroimidazole
1-30 mmol the compound 1 is dissolved in 10-300 mL dry dichloromethane solution. 5-30 mmol Triethylamine and 1-30 mmol phosphoryl cyanide are added sequentially and the reaction mixture is stirred for 12-18 hours. 50-500 mL dichloromethane is added into the solution. The reaction mixture is washed with 100 mL water and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 4:1. The obtained product is (1-[2-(2-(isobutylamino)-L-aspartic acid)acylamideethyl]-2 methyl-5-nitroimidazole.
C. Synthesis of Compound 3: 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole
1-30 mmol the compound 2 is dissolved in 1-300 mL trifluoacetic acid. The mixture is stirred at room temperature for 20-30 min. Extra trifluoacetic acid is removed and 5-10 mL hexane is added to remove a small amount of trifluoacetic acid. The reaction product is dissolved in 10-300 mL water. The pH value is the adjusted to 9. The reaction product 3 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole separated is re-crystallized in a mixture of water:ethanol of 1:1.
The chemical reactions of the current invention are simple. The final product (aspartic acid-methyl-nitroimidazole) ( FIGS. 2 , 3 , 4 ) has a high yield. The purification method is also very simple. The raw product (aspartic acid-methyl-nitroimidazole) has a purity of 95%. After being chelate with radioactive nuclides, the product has a high radioactivity ( FIG. 5 ).
Still in accordance with one embodiment of the invention, there provided is a method to apply the nitroimidazole-amino acid nuclear hypoxia contrast medium in the production of the imaging contrast medium.
A further goal of the current invention is apply the nitroimidazole-amino acid nuclear hypoxia contrast medium in the diagnosis of malignant tumors, evaluation after tumor operation or treatment, and the brain scan of cerebral hypoxia caused by cerebral thrombosis.
For example: (1) cerebral thrombosis: Cerebral thrombosis leads to hypoxia and thus death of cerebral cells. This so caused stroke is very normal in middle aged and older people. Early clinic detection of the disease provides a time window for the treatment of the disease and is very crucial for the prognosis of the patients. Clinically, using CT and MRI to detect cerebral thrombosis and cerebral apoplexy at an early stage is very difficult and the clinical treatment of these two diseases is very different. The contrast medium of the current invention is functional contrast medium, and therefore it can detect these two brain diseases at an early stage. In addition, the contrast medium of the current invention can also trace the prognosis of the patients after they have been treated.
(2) Tumors: The rapid growth of tumor cells results in a lack of blood and oxygen supply to the central part of the tumor, and this leads to the formation of hypoxic and necrotic tissues. The contrast medium of the current invention has a great imaging effect for tumor cells and is very sensitive for tumor imaging (it can image tumor with a size more than 1.5 cm). 3D tumor images can be obtained via SPECT (ECT), which facilitates an early detection of the location, size and degree of malignancy of the tumor. Furthermore, the contrast medium of the current invention can also be used to image the tumor on a regular basis and the images can be used to trace and evaluate the effect of the treatment as well as the resistance of the tumors against the treatment.
The contrast medium of the current invention can be used in imaging cerebral thrombosis, tumors or other diseases such as ulceration, thrombosis, etc.
There are two mechanisms of the tumor-targeting effect of the contrast medium of the current invention: 1). the rapid growth of tumor cells results in a lack of blood and oxygen supply to the central part of the tumor, and this leads to the formation of hypoxic and necrotic tissues. Due to the presence of the hypoxic tissue in the tumor, the contrast medium of the current invention can be used to image tumors. 2). Normal cells can synthesize asparagine which is essential for the growth of the cells. Tumor cells do not have this function, and has to rely on eternal supply of asparagines. The contrast medium of the current invention contains asparagines, and therefore can be used in tumor imaging.
The contrast medium of the current invention is a novel hypoxic-cell-targeting contrast medium. This contrast medium can chelate radioactive nuclides generally used clinically, such as 99m Tc, 113m In. After being injected into the human body, the contrast medium is specifically accumulated in hypoxia cells and tissues. Through SPECT (ECT) or γ-camera, hypoxia lesions can be traced and can be clearly imaged after data processing on computers. Hence, the doctors can accurately diagnose the location, size, and the degree of malignancy of the hypoxia tissues. Medically, the hypoxia lesions mentioned above refer to certain tissues in human body which are lacking supply of oxygen and blood so that the cells and the tissues are dead (such as cerebral thrombosis, tumors, and other thrombosis).
Therefore, the contrast medium of the current invention can be used in the diagnosis of malignant tumors, evaluation after tumor operation or treatment, and the brain scan of cerebral hypoxia caused by cerebral thrombosis.
The method to produce the contrast medium of the current invention is simple and convenient, and has a high clinic application value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 the conversion of the R—NO 2 group of the nitroimidazole molecule into R—NH 2 group in hypoxic cells;
FIG. 2 1 H-NMR spectroscopy of the final reaction product aspartic acid-methyl-nitroimidazole;
FIG. 3 13 C-NMR spectroscopy of the final reaction product aspartic acid-methyl-nitroimidazole;
FIG. 4 mass spectroscopy (MS) of the final reaction product aspartic acid-methyl-nitroimidazole;
FIG. 5 radioactive TLC diagram of 99m Tc aspartic acid-methyl-nitroimidazole;
FIG. 6 1 H-NMR spectroscopy of the final reaction product aspartic acid-aspartic acid-methyl-nitroimidazole;
FIG. 7 13 C-NMR spectroscopy of the final reaction product aspartic acid-aspartic acid-methyl-nitroimidazole;
FIG. 8 mass spectroscopy (MS) of the final reaction product aspartic acid-methyl-nitroimidazole;
FIG. 9 1 H-NMR spectroscopy of the final reaction product aspartic acid-glutamic acid-methyl-nitroimidazole;
FIG. 10 13 C-NMR spectroscopy of the final reaction product aspartic acid-glutamic acid-methyl-nitroimidazole;
FIG. 11 mass spectroscopy (MS) of the final reaction product aspartic acid-glutamic acid-methyl-nitroimidazole;
FIG. 12 the image of mice (with breast cancer cells on the legs) on γ-camera after the nuclide contrast medium is intravenous injected; and
99m Tc L-aspartic acid (T/M=1.1) 99m Tc L-aspartic acid-methyl-nitroimidazole (T/M=4.3) 99m Tc L-aspartic acid (T/M=2.5) 99m Tc L-aspartic acid-methyl-nitroimidazole (T/M=3.7)
FIG. 13 the image of mice (with breast cancer cells on the legs) on γ-camera after the nuclide contrast medium is intravenous injected.
99m Tc L-aspartic acid (T/M=2.2) 99m Tc L-aspartic acid-methyl-nitroimidazole (T/M=4.3) 99m Tc L-aspartic acid (T/M=1.5) 99m Tc L-aspartic acid-methyl-nitroimidazole (T/M=4.1)
DETAILED DESCRIPTION OF THE EMBODIMENTS
Example 1
The amino group (—NH 2 —) of 1-(2-aminoethyl)-2 methyl-5-nitroimidazole is reacted with the α carboxyl group (—COOH) of L-aspartic acid, a H 2 O molecule is released and an amide group is formed and the reaction product is 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole (FW=285) (Formula 12),
and thus the contrast medium of the current invention is formed. The reaction step (Reaction 1) is very simple.
The yield of the final product (MNA) ( FIGS. 2 , 3 , 4 ) is pretty high (73%), and is easy to purify. The purity of the raw product (aspartic acid-methyl-imidazole) can reach 95%, and after it is chelate with the radioactive nuclide, the radioactivity is high ( FIG. 5 ).
A. Synthesis of Compound 1: (1-[2-(2-(isobutylamino)-4-benzyl-L-aspartic ester)acylamideethyl]-2 methyl-5-nitroimidazole
3.2 g, 10.0 mmol 2-(isobutylamino)-4-benzyl-L-asparticester is dissolved in 100 mL dry dichloromethane solution. 4.2 mL (30.0 mmol) Triethylamine, 10.0 mmol (2.6 g) 1-(2-aminoethyl)-2 methyl-5-nitroimidazole and 1.7 mL (10.0 mmol) phosphoryl cyanide are added sequentially at room temperature into the dichloromethane solution. The solution is stirred for 2 hours. 100 mL dichloromethane is then added into the mixture. The reaction mixture is washed with water twice (50-60 mL each time) and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 4:1. 3.7 g (1-[2-(2-(isobutylamino)-4-benzyl-L-aspartic ester)acylamideethyl]-2 methyl-5-nitroimidazole is obtained (product yield: 80.6%).
B. Synthesis of Compound 2: (1-[2-(2-(isobutylamino)-L-aspartic acid)acylamideethyl]-2 methyl-5-nitroimidazole
20 g (4.4 mmol) the compound 1 is dissolved in 30 mL dry dichloromethane solution. 1.8 mL (13.2 mmol) triethylamine and 0.7 mL (4.4 mmol) phosphoryl cyanide are added sequentially and the reaction mixture is stirred for 12-18 hours. 100 mL dichloromethane is added into the solution. The reaction mixture is washed with water twice (50 mL each time) and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 4:1. 1.5 g (1-[2-(2-(isobutylamino)-L-aspartic acid)acylamideethyl]-2 methyl-5-nitroimidazole is obtained (product yield: 93.5%).
C. Synthesis of Compound 3: 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole
1.7 g (5.0 mmol) the compound 2 is dissolved in 4.0 mL trifluoacetic acid. The mixture is stirred at room temperature for 20-30 min. Extra trifluoacetic acid is removed and a small amount of hexane is added (twice, 5-10 mL each time) to removed a small amount of trifluoacetic acid. The reaction product is dissolved in 50 mL water. The pH value is the adjusted to 9. 1.3 g reaction product 3 1-(2-L-asparaginylethyl)-2 methyl-5-nitroimidazole separated is re-crystallized in a water:ethanol 1:1 solution (product yield: 91.5%).
Example 2
The amino group (—NH 2 —) of 1-(2-aminoethyl)-2-methyl-5-nitroimidazole is reacted with the α carboxyl group (—COOH) of L-aspartic acid, a H 2 O molecule is released and an amide group is formed. After that, the other carboxyl group (—COOH) of the L-aspartic acid molecule is reacted with the amino group (—NH 2 —) of another L-aspartic acid molecule, a H 2 O molecule is released and another amide group is formed. This contrast medium has two L-aspartic acid molecules connected to each other (Formula 13).
The reaction step is shown as follows (reaction 2).
The final products ( FIGS. 6 , 7 , 8 ) have yield of (75%). The purification method is easy. The raw product (aspartic acid-aspartic acid-methyl-nitroimidazole) has a purity of higher than 90%.
D. Synthesis of Compound 4
0.4 g (1.0 mmol) the compound 2 is dissolved in 10.0 mL dry trifluoacetic acid. 0.7 mL triethylamine (5.0 mmol), 0.3 g hydrochloric acid ditertiarybutyl-L-aspartic ester (1.0 mmol) and 0.2 mL phosphoryl cyanide are added sequentially at room temperature into the dichloromethane solution. The solution is stirred for 12 hours. 20 mL dichloromethane is then added into the mixture. The reaction mixture is washed with water twice (20-30 mL each time) and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 95:5. 0.48 g compound 4 is obtained (product yield: 79.2%).
E. Synthesis of Compound 5: (1-(2-L-asparaginyl(β-L-asparaginyl)ethyl)-2-methyl-5-nitroimidazole
1.5 g (2.5 mmol) the compound 4 is dissolved in 40 mL NaOH/ethanol solution (20 mL, 1.0 M NaOH and 20 mL ethanol) and the solution is stirred for 12 hours. The white solid product is filtered out and 0.85 g compound 5 ((1-(2-L-asparaginyl(β-L-asparaginyl)ethyl)-2-methyl-5-nitroimidazole is re-crystallized in 30 mL water and ethanol mixture solution (1:1) (yield is 85.2%).
Example 3
The amino group (—NH 2 —) of 1-(2-aminoethyl)-2-methyl-5-nitroimidazole is reacted with the α carboxyl group (—COOH) of glutamic acid, a H 2 O molecule is released and an amide group is formed. After that, the other carboxyl group (—COOH) of the L-glutamic acid molecule is reacted with the amino group (—NH 2 —) of another L-aspartic acid molecule, a H 2 O molecule is released and another amide group is formed. This contrast medium has one glutamic acid and one aspartic acid molecules connected to each other (Formula 14).
The reaction step is shown as follows (reaction 3).
The final products ( FIGS. 9 , 10 , 11 ) have yield of (62%). The purification method is easy. The raw product (aspartic acid-aspartic acid-methyl-nitroimidazole) has a purity of higher than 90%.
A. Synthesis of Compound 1
4.2 mL triethylamine (30.0 mmol), 2.6 g 1-(2-ethylamino)-2-methyl-5-nitroimidazole (10.0 mmol) and 1.7 mL phosphoryl cyanide (10.0 mmol) are added sequentially to 50 mL dry trifluoacetic acid containing 3.0 g 2-isobutyric acid amino-5-tertbutyl-L-glutamate (10.0 mmol) and the solution is stirred at room temperature for 3 hours. 100 mL dichloromethane is then added into the mixture. The reaction mixture is washed with water twice (50-60 mL each time) and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 4:1. 4.0 g compound 1 is obtained (product yield: 88%).
B. Synthesis of Compound 2: Troimidazole
2.3 g (5.0 mmol) the compound 1 is dissolved in 40 mL NaOH/ethanol solution (20 mL, 1.0 M NaOH and 20 mL ethanol) and the solution is stirred for 12 hours. The solution has been dried. The white solid product is separated using silica gel column. Water and ethanol are in the mobile phase in a volume ratio of 3:7. 1.8 g compound 2 is obtained (product yield: 91%).
C. Synthesis of Compound 3
0.4 g (1.0 mmol) the compound 1 is dissolved in 10 mL dry dichloromethane solution. 0.7 mL (5.0 mmol) triethylamine. 0.28 g hydrochloric acid ditertiarybutyl-L-aspartic ester (1.0 mmol) and 0.16 mL phosphoryl dicyanide are added sequentially at room temperature into the dichloromethane solution. The solution is stirred for 3 hours. 20 mL dichloromethane is then added into the mixture. The reaction mixture is washed with water twice (20-30 mL each time) and dried with MgSO 4 . The final products are separated using silica gel column. Dichloromethane and ethanol are in the mobile phase in a volume ratio of 95:5. 0.46 g compound 3 is obtained (product yield: 74%).
D. synthesis of Compound 4: (1-(2-α-L-glutamine (β-L-asparaginyl)ethyl)-2-methyl-5-nitroimidazole
At 0° C., 3.1 g (5.0 mmol) the compound 3 is dissolved in 4.0 mL trifluoacetic acid. The mixture is stirred at room temperature for 20 min. Extra trifluoacetic acid is removed and a small amount of hexane is added (twice, 5-10 mL each time) to removed a small amount of trifluoacetic acid. The reaction product is dissolved in 5 mL water. The pH value is the adjusted to 8-9 with 10% NaOH. 20 mL ethanol is then added. The filtered product is re-crystallized in 30 mL water and ethanol (1:1) solution and 1.4 g compound 4 (1-(2-α-L-glutamine (β-L-asparaginyl)ethyl)-2-methyl-5-nitroimidazole (70%) is obtained.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A hypoxia contrast medium including nitroimidazole-amino acid chelate with a positively charged radioactive nuclide, a preparation method and use thereof. The contrast medium can be used in imaging cerebral thrombosis, tumors or other diseases such as ulceration, thrombosis, and so on. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a hydrogen-absorbing alloy having a BCC structure (body-centered cubic structure) as a crystal structure and, more particularly, to a hydrogen-absorbing alloy for a nickel-hydride cell having an excellent discharge capacity and excellent durability (cycle characteristics).
[0003] 2. Description of the Prior Art
[0004] A hydrogen-absorbing alloy can absorb and store a volume of hydrogen gas more than about 1,000 times the volume of the alloy itself as means for storing and transporting hydrogen, and its density is equal to, or greater than, that of liquid or solid hydrogen. It has long been known that metals and alloys having a body-centered structure (hereinafter called the “BCC”), such as V, Nb, Ta, TiVMn system and TiVCr system alloys absorb and store greater amounts of hydrogen than AB 5 type alloys such as LaNi 5 and AB 2 type alloys such as TiMn 2 that have been already put into practical application. This is because the number of hydrogen absorbing sites in the crystal lattice of the BCC structure is large, and the hydrogen-absorbing capacity according to calculation is as great as H/M=2.0 (about 4.0 wt % in alloys of Ti or V having an atomic weight of about 50).
[0005] Though hydrogen-absorbing alloys have been used for cell electrodes in this field, the number of alloys having a body-centered cubic structure (BCC) is small, and Laves phase alloys of the AB 2 type such as misch metal have been mainly disclosed.
[0006] Japanese Unexamined Patent Publication (Kokai) No. 6-228699 discloses a hydrogen-absorbing alloy for an electrode of an alkali secondary cell which is expressed by the formula TixVyNiz and the composition range of which falls within the range encompassed by Ti 5 V 90 Ni 5 , Ti 5 V 75 Ni 20 , Ti 30 V 50 Ni 20 and Ti 30 V 65 Ni 5 . Further, Japanese Unexamined Patent Publication (Kokai) No. 7-268514 discloses a hydrogen-absorbing alloy, and a hydrogen-absorbing alloy electrode, wherein a phase comprising the AB 2 type Laves alloy phase, as the principal phase, exists while it forms a three-dimensional stitch skeletal structure in the base phase comprising a Ti-V type solid solution alloy, and Japanese Unexamined Patent Publication (Kokai) No. 9-49046 discloses a hydrogen-absorbing alloy, and an electrode, expressed by the general formula TixVyMzNi1-x-y-z (where M is at least one element selected from the group consisting of Cr, Mo and W, and 0.2≦x≦0.4, 0.3≦y<0.7, 0.1≦z≦0.3 and 0.6≦x+y+z≦0.95), and having a body-centered cubic structure. Japanese Unexamined Patent Publication (Kokai) No. 9-53135 describes a hydrogen-absorbing alloy, and an electrode, expressed by the general formula TixVyNi1-x-y-z (where M is at least one kind of element selected from the group consisting of Co, Fe, Cu and Ag, and 0.2≦x≦0.4, 0.3≦y<0.7, 0.1≦z≦0.3 and 0.6≦x+y+z≦0.95) and having a body-centered cubic structure. Furthermore, Japanese Unexamined Patent Publication (Kokai) No. 9-53136 describes a hydrogen-absorbing alloy, and an electrode, expressed by the general formula TixVyMzNi1-x-y-z (where M is at least one kind of the element selected from the group consisting of Al, Mn and Zn, 0.2≦x≦0.4, 0.3≦y<0.7, 0.1≦z≦0.3 and 0.6≦x+y+z≦0.95), and having a body-centered cubic structure.
[0007] Further, Japanese Unexamined Patent Publication (Kokai) No.9-53137 describes a hydrogen-absorbing alloy, and an electrode, expressed by the general formula TixVyMzNi1-x-y-z (where M is at least one kind of element selected from the group consisting of Zr and Hf, 0.2≦x≦0.4, 0.3≦y<0.7, 0.1≦z≦0.3 and 0.6≦x+y+z≦0.95), and having a body-centered cubic structure.
[0008] However, all these BCC alloys contain large amounts of V and their durabilities (cycle characteristics) are not sufficient.
SUMMARY OF THE INVENTION
[0009] In order to convert the Ti-V-Cr type alloy, as one of the conventional BCC type hydrogen-absorbing alloys, to a quaternary or quinary alloy having a periodical structure by substituting V in the Ti-V-Cr alloy with other element and controlling the lattice constant, the present invention aims at providing a hydrogen-absorbing alloy, and an electrode, that can be used for cells having excellent cycle characteristics.
[0010] Another object of the present invention is to make it possible to produce an alloy, which is advantageous from the aspect of the production cost and has excellent hydrogen absorption and desorption characteristics, by heat-treatment, and to provide a hydrogen-absorbing alloy, and an electrode, that can be applied on the industrial scale to Ni-MH (Metallic hydride) cells.
[0011] Another object of the present invention is to provide an alloy for cells, which has a periodical structure by a spinodal decomposition and can be produced at a low cost on the industrial scale, by using the novel BCC alloy and heat-treatment described above through an optimum production process.
[0012] The gist of the present invention will be described as follows.
[0013] (1) A hydrogen-absorbing alloy comprises a composition expressed by the general formula:
Ti (100- a - b - c - d )Cr a V b Ni c X d ,
[0014] where X is at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, each of a, b, c and d is represented, in terms of atomic %, by the relations 8≦a≦50, 30<b≦60, 5≦c≦15, 2≦d≦10 and 40≦a+b+c+d≦90; and a crystal structure of a principal phase which is a body-centered cubic structure.
[0015] (2) A hydrogen-absorbing alloy comprises a composition expressed by the general formula:
Ti (100- a - b - c - d ) Cr a V b Ni c X d ,
[0016] where X is at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt and each of a, b, c and d is represented, in terms of atomic %, by the relations 8≦a≦50, 0<b≦30, 5≦c≦15, 2≦d≦10 and 40≦a+b+c+d≦90; and a crystal structure of a principal phase which is converted to a body-centered cubic structure by heat-treatment.
[0017] (3) A hydrogen-absorbing alloy comprises a composition expressed by the general formula:
Ti (100- a - b - c - d ) Cr a M b Ni c X d ,
[0018] where M is at least one of Mo and W, X is at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, and each of a, b, c and d is expressed, in terms of atomic %, by the relations 8≦a≦50, 30<b≦60, 5≦c≦15, 2≦d≦10 and 40≦a+b+c+d≦90; and a crystal structure of a principal phase which is converted to a body-centered cubic structure by heat-treatment.
[0019] (4) A hydrogen-absorbing alloy having the composition according to any of claims 1 through 3 , wherein the principal phase exists within the range where a body-centered cubic structure appears and a spinodal decomposition occurs, exclusive of a C14 single-phase region, where C14 is a typical structure of a Laves phase and MgZn 2 type crystal structure; and said principal phase has a regular periodical structure and its apparent lattice constant is from 0.2950 nm to 0.3150 nm.
[0020] (5) A hydrogen-absorbing alloy according to item (2) or (3), wherein heat-treatment comprises solution treatment conducted for 1 min to 100 hr at a temperature range of from 700 to 1500° C., and one or both treatments selected from quenching and aging of from 350 to 1200° C. after solution treatment.
[0021] (6) A cell electrode comprising said hydrogen-absorbing alloy according to any one of items (1) through (4).
[0022] (7) A cell electrode according to item (6), wherein said cell electrode has excellent cell characteristics in the maximum discharge capacity and the capacity retaining ratio after 100 charge/discharge cycles.
[0023] (8) A cell electrode according to item (7), wherein the maximum discharge capacity is 375 to 465 mAh/g and the capacity retaining ratio after 100 charge/discharge cycles is 80 to 95%.
BRIEF DESCRIPTION OF THE DRAWING
[0024] [0024]FIG. 1 is a diagram showing the relationship between the number of charge/discharge cycles and the discharge capacity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] The present invention uses a Ti-Cr-V type alloy as the basis and improves the characteristics of a cell electrode. In other words, elution to an electrolyte is prevented as much as possible by V, and cycle characteristics, etc., are improved by imparting the elution resistance. Further, the present invention uses the BCC type structure as the principal phase and imparts the periodical structure by the spinodal decomposition. Therefore, Ni as the fourth element and Y, lanthanoids, Pd, Pt, etc., as the fifth element are added to the TiCrV alloy or TiCr(Mo,W) alloy having a body-centered cubic structure having a high capacity so that, when the alloy is used as an alloy for the electrode of nickel-hydride cells, discharge capacity and durability (cycle characteristics) can be improved.
[0026] The growth of the modulated metallic structure due to the spinodal decomposition in the present alloy can be divided into a spinodal decomposition stage, at which a concentration amplitude is increased from a concentration fluctuation of the initial stage, and a wavelength increasing stage at which the wavelength of the modulated structure formed by the former stage is increased. In the Ti-Cr-V system and in the Ti-Mn-V system, the reaction in the spinodal decomposition stage is extremely fast. This reaction finishes at the time of casting and solidification and quenching after heat-treatment, for example, and forms the modulated structure. The present invention makes it possible to control the hydrogen absorption quantity, the desorption characteristics and particularly, the plateau flatness, by controlling the increase of the concentration wavelength after the decomposition has already finished.
[0027] The first invention improves the cell characteristics by decreasing V while keeping the alloy ratio within the range of the body-centered cubic structure in the Ti-Cr-V system phase diagram and adds Ni so as to achieve a high capacity and a catalytic operation. The addition amount of Ni for remarkably exhibiting this effect is from 5 to 15% and preferably from 10 to 15%. Further, at least one member selected from the group consisting of Y, lanthanoids, Pd and Pt is added, preferably in a amount of 2 to 10%, so as to improve the charge and discharge characteristics, particularly the cycle characteristics of the negative electrode, at the time of discharge at a high efficiency. From the aspect of the improvement in durability, these elements form stable oxides and contribute to the improvement of durability. At the same time, because these elements have the catalytic operation for dissociating the hydrogen molecules into the atoms, they can enhance the reaction rate with hydrogen when they are used as the addition elements of the hydrogen-absorbing alloy of the present invention. Incidentally, if the addition amounts of these elements are outside the range stipulated in the scope of claim, the body-centered cubic structure cannot be obtained, so that the hydrogen absorption quantity decreases and the cell capacity deteriorates.
[0028] The second invention further reduces the V content, basically keeps other alloy components at the same level as the level of the first invention, and achieves the periodical structure by heat-treatment. This heat-treatment exhibits the following effect. Namely, the lattice strain occurring in the interface of the two phases changes the distribution state of the hydrogenation strain resulting from hydrogenation, as described above. Particularly in the alloys having the BCC structure such as the alloy of the present invention, the strain brought forth by hydrogenation exerts great influences on the pressure difference (hysteresis) between hydrogen absorption and desorption. Because such an initial strain can be controlled by the heat-treatment in the alloys having a fine structure as in the alloy of the present invention, an optimum strain distribution with a small hysteresis can be generated.
[0029] In the present invention, the effect of the solution treatment can hardly be obtained if the temperature is less than 700° C. and this effect tends to get into saturation if the temperature exceeds 1,500° C. Therefore, the temperature is preferably within the range of 700 to 1,500° C. The effect of the solution treatment is not sufficient if the treatment time is less than one minute and this effect tends to get into saturation if the treatment time exceeds 100 hours. Therefore, the treatment time is preferably within the range of one minute to 100 hours. This solution treatment provides also the effect of the homogenization treatment.
[0030] A cooling treatment and/or an aging treatment at 350 to 1,200° C. may be carried out either alone or in combination as a post-treatment of this solution treatment and preferably, the cooling treatment is a quenching treatment. In some cases, the alloy is kept at a temperature lower than the solution heat-treatment temperature before the cooling treatment. When the aging treatment is not conducted, the solution treatment is synonymous with the homogenization treatment.
[0031] The third invention adds Mo and W as the elements which make it easy to obtain the body-centered cubic structure by the heat-treatment instead of further decreasing the V content. Since this composition comprises Ti, Cr and Mo and/or W as the components, the cost becomes lower than the conventional hydrogen-absorbing alloys using V, etc.. Because Mo and/or W is the component that replaces V, etc., the range of the solution treatment in the phase diagram can be expanded. In consequence, the phase separation takes place sufficiently, and an alloy having excellent hydrogen absorption and desorption characteristics in the two-phase state can be obtained. As to the addition amount, the alloy cannot be transformed to the BCC even when the heat-treatment is carried out under the addition of Mo and/or W of greater than 30 at %. If it exceeds 60 at %, the alloy is not practical because the hydrogen absorption quantity deteriorates. Therefore, the range stipulated in the scope of claim is adopted as the preferred range.
[0032] The fourth invention stipulates that the lattice constant (mean lattice constant of two phases) of the composition is not greater than the boundary line of 0.3150 nm, its apparent lattice constant (mean lattice constant of two phases) is not smaller than the boundary line of 0.2950 nm, and the composition is within the range in which the body-centered cubic structure appears with the exception of the C14 single-phase range. When these conditions are satisfied, the hydrogen absorption and desorption function of the hydrogen-absorbing alloy can be sufficiently exhibited, and an electrode for a high capacity cell can be formed.
[0033] As described above, the alloy of the present invention has excellent hydrogen absorption and desorption characteristics and can be used as an electrode for a hydride electrode having a high capacity and high durability, for an alkali cell.
[0034] Hereinafter, the present invention will be explained in further detail with reference to Examples thereof.
EXAMPLES
[0035] Hydrogen-absorbing alloys were prepared as examples of the present invention, and electrodes were produced so as to test cell characteristics. First, alloys having the compositions within the range of the present invention and those having the composition outside the range of the present invention, as Comparative Examples, were used as tabulated in Table 1. (Incidentally, the lattice constant of Example 2 was 0.3143 nm.)
TABLE 1 max. capacity discharge retaining ratio alloy composition capacity after 100 cycles No. (at %) (mAh/g) (%) Inventive Ti 32 Cr 15 V 40 Ni 10 La 3 433 87 Ex. 1 Inventive Ti 30 Cr 15 V 40 Ni 10 La 5 462 85 Ex. 2 Inventive Ti 25 Cr 15 V 40 Ni 10 La 10 416 82 Ex. 3 Inventive Ti 36 Cr 16 V 40 Ni 15 La 3 407 86 Ex. 4 Inventive Ti 29 Cr 13 V 40 Ni 15 La 3 354 85 Ex. 5 Inventive Ti 32 Cr 15 V 40 Ni 10 Ce 3 431 87 Ex. 6 Inventive Ti 32 Cr 15 V 40 Ni 10 Mm 3 428 87 Ex. 7 (Mm: misch metal) Inventive Ti 37 Cr 10 V 40 Ni 10 Pd 3 378 89 Ex. 8 Inventive Ti 31 Cr 14 V 40 Ni 10 Pt 5 393 90 Ex. 9 Inventive Ti 53 Cr 24 V 10 Ni 10 La 3 419 94 Ex. 10 Inventive Ti 46 Cr 21 V 20 Ni 10 La 3 421 91 Ex. 11 Inventive Ti 39 Cr 18 V 30 Ni 10 La 3 427 90 Ex. 12 Inventive Ti 41 Cr 38 Mo 6 Ni 10 La 5 445 94 Ex. 13 Inventive Ti 43 Cr 39 W 3 Ni 10 La 5 458 92 Ex. 14 Comparative Ti 28 Cr 32 V 40 17 — Ex. 1 Comparative Ti 25 Cr 29 V 36 Ni 10 154 — Ex. 2 Comparative Ti 43 Cr 41 Mo 6 Ni 10 135 — Ex. 3 Comparative Ti 25 Cr 12 V 40 Ni 20 La 3 181 — Ex. 4 Comparative Ti 17 Cr 8 V 62 Ni 10 La 3 414 61 Ex. 5
[0036] Examples Nos. 1 to 9 of the present invention were within the range of the first invention. While the V content was kept a little high, at least one of lanthanoids, Pd and Pt was added, and the proportion of addition and the proportion of the Ni content were changed. Examples Nos. 10 to 12 of the invention kept the V content a little low, and Examples 13 and 14 did not use V at all and Mo and/or W was added instead.
[0037] All the samples of Examples of the present invention used an ingot of about 20 g molten by arc melting inside argon by using a water cooled copper hearth. The data of all the Examples of the present invention were the measurement data obtained by pulverizing an as-cast ingot in air, repeating four cycles an activation treatment by applying a vacuum, at 500° C., to 10 −4 Torr and hydrogen pressurization at +50 atm, and then conducting a vacuum origin method stipulated for a pressure composition isothermal measurement method as a volumetric method (JIS H7201) to evaluate the hydrogen absorption quantity of each alloy and its absorption and desorption characteristics. A thin film was prepared, by ion milling from a bulk sample, for the observation of each sample by a transmission electron microscope.
[0038] Structural analysis of each alloy was made by using a transmission electron microscope and its accessory EDX (energy dispersive X-ray spectrometer). Further, a crystal structure model was prepared on the basis of the information obtained by the transmission electron microscope, and Riedveld analysis of the powder X-ray diffraction data was effected. The results of measurement of the alloy composition, the lattice constant of each alloy and its hydrogen absorption and desorption quantity revealed that, when the lattice constant mean value was less than 0.2950 nm, the hydrogen absorption and desorption quantity was low and, when the lattice constant mean value became greater than 0.2950 nm, the hydrogen absorption and desorption quantity increased, and reached the maximum near 0.3150 nm. When the lattice constant mean value increased thereafter, the hydrogen absorption and desorption quantity decreased drastically. It could be concluded from the results that, in order to obtain a hydrogen absorption and desorption quantity greater than a predetermined quantity, the mean value of the lattice constant of the two-phase in the nano-order that constituted the BCC phase was preferably within the range of 0.2950 nm to 0.3150 nm.
[0039] Next, an electrode was produced from each alloy of the Examples of the present invention, and the Comparative Examples, by conducting compression molding of alloy powder, and a Ni-hydride type cell of the prior art, which included a Ni positive electrode having a sufficient capacity and large amounts of electrolyte, was produced by using each electrode.
[0040] [0040]FIG. 1 shows the relationship between the number of charge and discharge cycles and the discharge capacity when charging at a low current and discharging were repeatedly executed in Example 2 of the present invention and in Comparative Examples 1 and 5. It could be appreciated from this result that in Example 2 of the present invention, the drop of the discharge capacity was small and the cycle characteristics could be remarkably improved.
[0041] In the same way, Table 1 completely tabulates the maximum discharge capacity and the cycle characteristics for all the alloys inclusive of the rest of Examples of the present invention.
[0042] It will be appreciated from the result tabulated in Table 1 that the maximum discharge capacity was within the range of 378 to 462 mAh/g in Examples of the present invention and the capacity retaining ratio after 100 cycles was 82 to 94%. Both of these values were superior to the values of Comparative Examples. Incidentally, the measurement of the capacity retaining ratio was omitted in this table for the alloys whose maximum discharge capacity was not greater than 300 mAh/g.
[0043] The present invention provides an alloy which has excellent hydrogen absorption and desorption performance and whose body-centered cubic structure, having a high capacity as a cell characteristic, depends on the addition of the fourth or fifth element. Therefore, this alloy can be used as a high efficiency electrode for nickel-hydride cells, and can be applied as the electrode of cells having excellent discharge capacities and durabilities (cycle characteristics). | To provide a hydrogen absorbing alloy having a BCC (body-centered cubic structure) as a crystal structure, and particularly a hydrogen-absorbing alloy for a nickel-hydride cell having excellent discharge capacity and durability (cycle characteristics), said hydrogen-absorbing alloy having a composition expressed by the general formula Ti(100-a-b-c-d)CraVbNicXd, where X is at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, and each of a, b, c and d is represented, in terms of at %, by the relations 8≦a≦50, 30 <b≦60, 5≦c≦15, 2≦d≦10 and 40≦a+b+c+d≦90, wherein the crystal structure of a principal phase is a body-centered cubic structure, and further, the alloy contains at least one of Mo and W in place of V and at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, and its crystal structure is converted to the body-centered cubic structure by heat-treatment. | 8 |
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