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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrolytic processing device for metal strips. More specifically, the invention relates to an electrolytic processing device applicable to electrogalvanizing lines, electrotinning lines, electrolytic chromium processing, phosphorate processing, chromate treatments and so forth. The invention relates to a novel device for electrolytic processing of the surface of a metal strip.
2. Description of the Prior Art
So-called "radial-type" electrolytic processing devices are well-known in the field of metal strip surface treatment. In these electrolytic processing devices, a strip-shaped metal piece is fed along a meandering path defined by a plurality of rollers. During its travel, the metal strip is dipped into an electrolytic solution or electrolyte in an electrolytic tank. Within the electrolytic solution, an electric current is applied to the metal strip to induce electrolysis.
Recently, a great variety of surface treatments have been applied to metal strips. For example, even considering only electrogalvanization, not only pure zinc but also composites of zinc and iron, zinc and nickel and so forth are used as plating agents. Different electrolytic solutions are required for each separate plating process and plating agent. In other words, when two different electrolytic solutions are mixed, the efficiency of the solution drops significantly, which degrades plating quality.
Therefore, in conventional processes, when an electrolytic process is to be performed with a different plating agent, the electrolytic agent for one plating agent has to be drained completely before using another electrolytic solution adapted for another plating agent in the same electrolytic tank. It is standard practice as well to clean or wash the tank after draining one solution and before adding the next in order to completely avoid mixing of different solutions.
This clearly lowers the efficiency of the production line and thus increases the cost of electrolytic processing.
SUMMARY OF THE INVENTION
Therefore, it is a principle object of the present invention to provide an electrolytic processing device which can solve the aforementioned problem in the prior art.
Another and more specific object of the invention is to provide an electrolytic processing device which allows easy and convenient change of electrolytic solutions.
In order to accomplish the aforementioned and other objects, an electrolytic processing device, according to the present invention, has an electrolytic tank which comprises separably coupled upper and lower units. The upper and lower units can be coupled to each other to form a single electrolytic tank when electrolytic processing is to be performed. On the other hand, the upper and lower units can be replaced with other units independently. This allows the electrolytic solution in the lower unit to be changed simply by replacing the lower unit with another unit with a different electrolytic solution, without the need for draining and washing the lower unit used previously.
In accordance with one aspect of the present invention, a device for electrolytic processing or treatment comprises an electrolytic tank defining a path through which a metal strip passes, and an electrolytic bath containing an electrolytic solution, the tank being made up of first and second separable sections, an electric current supply means disposed in the metal strip path for supplying electric current during electrolytic processing, guide means for retaining the metal strip within the path in the tank and driving the metal strip to move through the electrolytic bath, and means, associated with the first and second sections, for assembling and separating same.
The electrolytic solution can be changed by exchanging at least one of the first and second sections which define the electrolytic bath.
The device further comprises a carrier supporting at least one of the first and second sections of the tank such that the supported section or sections are free to move toward and away from the metal strip path between a first working position and a second exchanging position.
The device further comprises an actuator associated with the first section of the tank for moving the latter between a first position at which the first section is assembled with the second section to form the tank and a second position at which the first section is separated from the second section.
The device further comprises an electrolytic solution supply and drain means for supplying the electrolytic solution to the electrolytic bath and draining the electrolytic solution. The electrolytic solution supply and drain means includes a movable section associated with the carrier for movement therewith and a stationary section, the movable section being connectable with the stationary section when the carrier is in the first working position. The electrolytic solution supply and drain means further comprises a coupling unit which establishes a one-touch coupling connecting the movable and stationary sections in a releasable and liquid-tight fashion. The coupling unit includes a sealing member with an interior chamber connected to a pneumatic pressure source so as to be held at a positive pressure high enough to establish a liquid-tight seal between the movable and stationary sections.
According to another aspect of the invention, a device for electrolytic processing or treatment comprises an electrolytic tank defining a path through which a metal strip passes, and an electrolytic bath containing an electrolytic solution, the tank being made up of first and second separable sections;
an electric current supply means disposed in the metal strip path for supplying electric current during electrolytic processing, guide means for retaining the metal strip within the path in the tank and driving the metal strip to move through the electrolytic bath, and lifter means, associated with the first and second sections, for guiding movement of one of the first and second sections relative to the other for assembling and separating same, the guide means including a lifting means connected to at least one of the first and second sections for moving at least corresponding one of the first and sections relative to the other.
The lifter means if movable toward and away from the metal strip path carrying at least one of first and second sections. The lifter means is movable mounted on a frame work which includes a stopper member adapted to contact with the opposing portion of the lifter means for centering the electrolytic tank relative to the centerline of the metal strip path.
The guide means comprises a rotary roller having a roller shaft rotating therewith, the roller shaft being adapted to be driven by a driving motor. The roller shaft is releasably coupled with a driving shaft of the driving motor when the lifter means with at least one of first and second sections is placed in an operating position, in which the electrolytic tank is centered with respect to the centerline of the metal strip path. The lifter means are so arranged as to place the axis of the roller shaft in alignment with the axis of the driving shafter while the lifter carries the electrolytic tank to the operating position. The roller shaft and the driving shaft are adapted to establish one-touch coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to limit the invention to the specific embodiment illustrated but are for explanation and understanding only.
In the drawings:
FIG. 1 is a fragmentary illustration of the overall structure of a sequential electrogalvanization line to which the preferred embodiment of an electrolytic processing device according to the invention is applied;
FIGS. 2a and 2b are cross sections through a device which actuates the upper and lower units of the electrolytic tank between the assembled position of following FIG. 3 and the separated position of following FIG. 4, in which FIG. 2a shows the device placing a tank in the assembled position and FIG. 2b shows the device placing a tank in the separated position;
FIG. 3 is a cross-sectional view of part of an electrolytic tank making up part of the preferred embodiment of the electrolytic processing device according to the invention, in which the electrolytic tank is shown in assembled form;
FIG. 4 is a cross-section view of the electrolytic tank of FIG. 3, in which an upper unit and a lower unit making up the tank are shown in their separated positions;
FIG. 5 is an enlarged section through the preferred embodiment of a piping system for the electrolytic processing device according to the invention showing the pipes separated from each other corresponding to separation of the upper and lower units;
FIG. 6 is section similar to FIG. 5, but showing the pipes joined corresponding to operation of the upper and lower units into the assembled position;
FIG. 7 is a further-enlarged section through a seal in the piping system of FIGS. 5 and 6;
FIG. 8 is a view similar to FIG. 3 showing a modification to the preferred embodiment of the electrolytic tank during electrolysis;
FIG. 9 is a view similar to FIG. 4 showing the tank of FIG. 8 in separated condition; and
FIG. 10 is a view similar to FIG. 2a showing a modification to the device of FIGS. 2a and 2b.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before disclosing the preferred embodiment of an electrolytic processing device according to the present invention in detail, the general structure of the electrogalvanization line will be described in order to facilitate better understanding of the invention.
As will be seen in FIG. 1, a metal strip 11 is continuously supplied from strip rolls 21a wound around pay-off rollers 21. The continuous metal strip 11 supplied by the strip rolls 21a is cut at its front end for preparation for connection with the end of the preceding strip at a sheering station 22. Then, the front end of the strip is connected to the rear end of the leading strip at a welding station 23 to form a single, continuous strip.
The strip is then fed to treatment stations 25, 26, 27, 28 and 29 through a louver station 24. The metal strip 11 meanders through the louver station 24 as shown. The louver station 24 ensures uniform feed of the metal strip 11 through the treatment stations 25, 26, 27, 28 and 29 even when the movement of the metal strip 11 is temporarily stopped at the welding station 23 to connect the leading strip and the trailing strip. In otherwords, the louver station 24 accumulates the metal strip 11 supplied through the welding station 23.
The treatment stations 25 and 26 constitute a pre-treatment section for degreasing, pickling, rinsing, etc. The treatment lines 27 and 28 constitute plating sections for electroplating. The treatment station 29 constitutes an post-treatment section for rinsing and other necessary treatment after plating.
The metal strip 11 electrogalvanized through the stations 25, 26, 27, 28 and 29 is wound on tension rollers 32 through a louver section 30 and a sheering section 31. In the sheering section, 31, the metal strip 11 is cut at a desired or predetermined length.
The preferred embodiment of an electrolytic processing device according to the present invention is applicable to either or both of the treatment stations 27 and 28.
FIGS. 2a, 2b, 3 and 4 illustrate the preferred embodiment of the electrolytic processing device according to the invention, which is applicable to the treatment stations 27 and 28. The electrolytic processing device generally comprises an electrolytic tank unit 100 mounted on a framework 200.
The electrolytic tank unit 100 includes a tank housing 102 which is separated into an upper section 104 and a lower section 106. The upper section 104 comprises vertical walls 104a defining a rectangular or square volume covered by a ceiling 104b. The upper section 104 also has a pair of downward extensions 104c extending downward from the lower end of the opposing pair of vertical walls 104a. An upper cover member 108 is secured to the ceiling 104b of the upper section 104 and has vertical walls 108a.
The lower section 106 also has vertical walls 106a defining a rectangular or square volume corresponding to that defined by the vertical walls 104a of the upper section 104. The vertical walls 106a are designed to coupled with the vertical walls 104a of the upper section 104 to define therein an electrolytic tank reception space 110. The lower section 106 also has pairs of upward extensions 106b extending upward from the top of the opposite pair of vertical walls 106a. The upward extensions 106b are located near the corners of the corresponding vertical walls 106a and of the downward extensions 104a of the upper section 104 when the upper section 104 is coupled with the lower section 106. The lower section 106 houses within its internal space 110 a electrolytic solution bath 112.
The electrolytic solution bath 112 has a pair of side walls 112a and a floor 112b. The floor 112b is curved as shown in longitudinal section of FIGS. 3 and 4 to form a hemicylindrical bath. The electrolytic solution bath 112 is filled with an electrolytic solution for electrolytic processing.
The upper section 104 supports a main roller 114. The main roller 114 has a central rotary shaft 114a rotatable therewith. The rotary shaft 114a passes through a pair of openings through the downward extension of the upper section 104 and has an axial extension 114b at one end thereof. Similarly, a pair of conductive rollers 116 made of an electrically conductive material have axial rotary shafts 116a respectively. The rotary shaft 116a of each conductive roller 116 rotates with the latter and is supported by the upward extensions 106b. Each rotary shaft 116a has an extension 116b passing through an opening through the upward extension. The extension 116b lies parallel to the extension 114b of the rotary shaft 114a of the main roller 114.
The lower section 106 of the tank housing 102 is mounted on a movable base 118 on wheels 120. The wheels 120 allow the movable base 118 with the lower section 106 to move along a horizontal member 202 of the frame work 200. The movable base 118 has an upwardly extending guide bar member 122. The upper section 104 has a slider 124 which slidingly engages the guide bar member 122 for vertical movement therealong. The slider 124 has an extension 126. A hydraulic cylinder 128 is also secured to the movable base 118 and has an actuation rod 130 connected to the extension 126 of the slider 124. The hydraulic cylinder 128 vertically actuates the slider, and thus the upper section 104, toward and away from the lower section 106.
Electric motors 132 are also mounted on horizontal stations 204 of the frame work 200. The electric motors 132 have driving shafts 132a and 132b. The driving shaft 132a of one of the motors 132 engages the extension 114b of the rotary shaft 114a of the main roller 114 during electrolysis. Similarly, the driving shafts 132a of the electric motors 132 engage respectively corresponding extensions 116b of the rotary shafts 116a of the conductive rollers 116.
As best shown in FIGS. 3 and 4, guide rollers 134 are provided on either side of the tank housing 102. The guide rollers 134 guide the metal strip 11 entering the electrolytic tank unit 100 through an entrance 136 defined in the tank housing 102 and exitting the exit 138.
The electrolytic solution tank 112 has a solution supply port 112c and a drain port 112d in its floor 112b. The solution supply port 112c is connected to a solution supply pipe 140 connected to an electrolytic solution source (not shown) through a stationary pipe 142 fixed to the framework 200 as shown in FIGS. 2a and 2b. Likewise, the drain port 112d is connected to a drainage pipe 144 connected to the drainage circuit (not shown) through the stationary pipe 142.
FIGS. 5 to 7 show the preferred structure of a pipe coupling for connecting the solution supply pipe 140 and the drainage pipe 144 to the stationary pipe 142. This coupling allows easy release while ensuring a liquid-tight seal. As shown in FIGS. 5 and 6, the stationary pipe 142 has a coupling flange 142a at its upper end. A groove 142b in the horizontal face of the coupling flange 142a receives a sealing member 146, such as a rubber O-ring. The coupling flange 142a also has a circular recess 142b which receives a flange 140a of the solution supply pipe 140. Although this is not shown the drawings, the drainage pipe 144 is coupled to the stationary pipe 142 in essentially the same manner as illustrated in FIGS. 5 to 7.
When the flange 140a of the solution supply pipe 140 engages the recess 142b of the coupling flange 142a of the stationary pipe 142, the sealing member 146 is elastically deformed to firmly and fully contact the lower surface of the flange 140a so as to establish a liquid-tight seal.
FIG. 7 shows the structure of the sealing member 146 employed in the preferred embodiment in greater detail. As shown in FIG. 7, the sealing member 146 comprises a hollow major section 146a and an annular flange section 146b which is what actually engages the recess 142b. The major section 146a defines therein an air chamber 146c connected to an air pressure source (not shown) through an air line 146d.
It should be appreciated that, although the shown embodiment employs a packing with a pneumatic chamber ensuring firm contact between the flange of the solution supply pipe and the packing, it would be possible to employ a fluid chamber connected to a fluid pressure source, i.e. to use fluid pressure as a replacement for air pressure. It should be further noted that the pipes making up the electrolytic solution supply circuit and drainage circuit are preferably lined with an acid- and oxidation-resistant material, such as natural hard rubber, when the corrosive electrolysis solution to be used has a relatively low PH. Furthermore, the pneumatic pressure in the chamber of the sealing member 146 may be set to be approximately 1.5 times higher than the required seal pressure.
It should be appreciated that the arrangement of the guide bar member 122 and the slider 124 guides movement of the upper section 104 toward and away from the lower section 106 and accurately positions the upper section relative to the lower section when the upper and lower sections are to be assembled.
The electrolytic tank 102 constructed as set forth above is used for electrolytic processing, such as electrogalvanization, electrotinning and so forth with an unique solution adapted to perform the desired electrolytic processing, in the assembled form illustrated in FIGS. 2b and 3.
As seen from FIGS. 2b and 3, in the assembled form, the lower section of the main roller 114 is immersed in the solution bath 112. As a result, the metal strip 11 at the lower edge of the main roller 114 is forced into the solution bath 112 and immersed in the electrolytic solution in the bath.
During operation, the extensions 114b and 116b of the rotary shafts 114a and 116a of the main roller 114 and the conductive rollers 116 engage the driving shafts 132a of respectively corresponding electric motors 132. As a result the electric motors 132 drive the main roller 114 and the conductive rollers 116 to rotate and so feed the metal strip 11 at a predetermined speed from the entrance 136 to the exit 138.
A plating current is applied to the one of conductive rollers 116 so as to pass the current through the metal strip 11 by way of the conductive rollers 116. The current flowing through the metal strip 11 induces electroplating. As set forth above, the metal strip 11 runs continuously through the solution bath 112 and the electrolytic processing is performed uniformly over the entire metal strip.
When a different electrolytic processing is required, the hydraulic cylinder 128 actuates the upper section 104 by way of the slider 124 upward along the guide bar 112. This upward movement of the upper section 104, moves the main roller 114 supported by the downward extension 104c upwards away from the metal strip 11. This releases the downward pressure on the metal strip 11 as shown in FIGS. 2a and 4.
In this embodiment, the outer periphery of the movable base 118 comes into contact with a stopper member 202a upwardly extending from the horizontal section 202 of the framework, which stopper member 202a sections for centering the upper and lower sections 104 and 106 of the tank housing relative to the centerline of the metal strip path. Also, the stopper member 202a and the guide bar member 122 as coupled with the slider 124 serves for positioning of the rotary shafts 114a and 116a relative to the driving shaft 132a of the electric motor.
At this position, the upper and lower sections 104 and 106 supported by the movable base 118 become free to move perpendicular to the travel of the metal strip. During this transverse movement of the movable base 118, the extensions 114b and 116b come out of engagement with the driving shafts 132a of the electric motors 132. At the same time, the solution supply pipe 140 and the drainage pipe 144 move slightly upward to separate the corresponding stationary pipes 142.
The movable base 118 is then shifted up to the position shown in FIG. 2b on the horizontal member 202 of the frame work 200. At the position of FIG. 2b, the hydraulic cylinder 128 is deactivated to lower the upper section 104 with the slider 124. This assembles the upper section with the lower section 106. At this position, the assembled solution tank 102 is removed and replaced with the other electrolytic tank unit 100 to change the electrolytic solution.
After replacing the electrolytic tank unit 100, the movable base 118 again moves transversely to the position of FIG. 2a. At the initial stage of this movement, the hydraulic cylinder 128 becomes active to shift the upper section 104 up to the disabled position. Then, the movable base 118 is driven back to the position of FIG. 2a. When the movable base 118 reaches the operating position of FIG. 2a, the extensions 116a of the conductive rollers 116 engage the driving shaft 132a of the electric motor 132. Also, at this time, the solution supply pipe 140 and the drainage pipe 144 engage the stationary pipes 142 in liquid-tight fashion.
Thereafter, the hydraulic cylinder 128 shifts the upper section 104 downward to assemble the electrolytic tank unit 102.
FIGS. 8 and 9 show a modified embodiment of the electrolytic processing unit. In this modification, the bath chamber 112' holding the electrolytic solution bath is in the upper section 104'. In this case, additional sealing rollers 150 defining the bath 112' to be filled with the electrolytic solution.
The main roller 114 sealingly contacts the sealing rollers 150 when the upper and lower sections 104' and 106' are assembled. Also, in this modification, the conductive rollers 116' are supported by the upper section 104 and the main roller 114' is supported by the lower section 106'.
As will be seen from FIG. 8, the electrolytic solution bath 112' is thus defined between the main roller 114' and the arcuate cell 152 attached to the upper section 104'. The longitudinal ends of the solution bath 112' are sealed by the sealing rollers 150. The solution bath 112' thus defined is connected to the electrolytic solution source and the drainage circuit via the electrolytic solution supply pipe 140' and 144' provided in the upper section 104'.
This modification also allows replacement of the various electrolytic solutions without requiring removal of the metal strip from the metal strip path and without requiring complete cleaning and washing of the electrolytic solution bath.
Although specific embodiments of the electrolysis processing device have been disclosed hereabove, the present invention can be implemented in various ways. For example, FIG. 10 shows a device which carries the upper and lower sections 104 and 106 of the tank housing 102 independently of each other. For this, the lower section 106 is mounted on a movable base 118' which has wheels 120. The movable base 118 can move transversely to the metal strip path along a lower horizontal station 202 L of the framework, as in the above preferred embodiment.
The upper section 104 is suspended from a carrier 160 with wheels 162. The carrier 160 is mounted on an upper horizontal station 202 U of the framework 200 and can move essentially transversely to the metal strip path along the upper horizontal section of the framework. One or more actuators 164, each of which may comprise a hydraulic cylinder, for example, are secured to the carrier with associated actuation rods 166 extending downwards. The upper section 104 of the tank housing 202 is connected to the lower ends of the actuation rods 166 via brackets 168.
With this construction of the modified embodiment, the upper section 104 is moved toward and away from the lower section 106 by the actuators 164 and can be moved transversely to the metal strip path independently of the lower section 106.
Therefore, the invention should be understood to include all possible embodiments and modifications to the shown embodiments which can be embodied without departing from the principles of the invention set out in the appended claims.
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An electrolytic processing device has an electrolytic tank which comprises separably coupled upper and lower units. The upper and lower units can be coupled to each other to form a single electrolytic tank when electrolytic processing is to be performed. On the other hand, the upper and lower units can be replaced with other units independently. This allows the electrolytic solution in the lower unit to be changed simply by replacing the lower unit with another unit with a different electrolytic solution, without the need for draining and washing the lower unit used previously.
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FIELD OF THE INVENTION
[0001] The invention relates generally to the field of digital image processing and, more particularly, to a method for relating a processing parameter to the contents of an image.
BACKGROUND OF THE INVENTION
[0002] In processing a digital image, it is common to sharpen the image and enhance fine detail with sharpening algorithms. Typically, this sharpening is performed by a convolution process (for example, see A. K. Jain, Fundamentals of Digital Image Processing , Prentice-Hall: 1989, pp. 249-251). The process of unsharp masking is an example of a convolution-based sharpening process. For example, sharpening an image with unsharp masking can be described with the equation:
s ( x,y )= i ( x,y )** b ( x,y )+β f ( i ( x,y )− i ( x,y )** b ( x,y )) (1)
[0003] where:
[0004] s(x,y)=output image with enhanced sharpness
[0005] i(x,y)=original input image
[0006] b(x,y)=lowpass filter
[0007] β=unsharp mask scale factor
[0008] f( )=fringe function
[0009] ** denotes two dimensional convolution
[0010] (x,y) denotes the x th row and the y th column of an image
[0011] Typically, an unsharp image is generated by convolution of the image with a lowpass filter (i.e., the unsharp image is given by i(x,y)**b(x,y)). Next, the highpass, or fringe, data is generated by subtracting the unsharp image from the original image (i.e., the highpass data is found with i(x,y)−i(x,y)**b(x,y)). This highpass data is then modified by either a scale factor β or a fringe function f( ) or both. Finally, the modified highpass data is summed with either the original image or the unsharp image to produce a sharpened image.
[0012] A similar sharpening effect can be achieved by modification of the image in the frequency domain (for example, the FFT domain) as is well known in the art of digital signal processing. Both the space domain (e.g., convolution methods) and the frequency domain methods of enhancing image sharpness are shift invariant methods. In other words, the sharpening process is invariant to the location within the image.
[0013] While these methods do indeed produce sharpened images, the quality of the resulting image often varies depending on the image content. For example, using the unsharp mask algorithm may produce a pleasing result for an image of a building. However, using the same algorithm may result in the undesirable appearance of oversharpening for an image of a human face (e.g., blemishes may be enhanced). The scale factor parameter may be modified individually for each scene by a human operator, but this is an expensive process.
[0014] In U.S. Pat. No. 5,682,443, Gouch and MacDonald describe a method of modifying, on a pixel by pixel basis, the parameters associated with the unsharp mask. In essence, the constant scale factor β in equation (1) is replaced with a scale factor which varies based on location β(x,y). These parameters are varied based on the color of the pixels in a local neighborhood. The method allows for the de-emphasis of the detail for pixels which are approximately flesh colored. This method is not shift invariant, however, since the fringe data is modified with a weighting function determined in accordance with the values of the sharp or unsharp data for each of the color components of each pixel. Consequently, this method is computationally intensive because the filter parameters are varied for each pixel. Additionally, this method can produce switching artifacts when one region of an image is sharpened far more or less than a nearby region.
[0015] Therefore, there exists a need for quickly sharpening, or otherwise improving, an image whereby the overall improvement of the image can be adjusted based on the material content of the image, and without the production of switching artifacts.
SUMMARY OF THE INVENTION
[0016] The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method of improving a characteristic of an image according to its material content comprises the steps of: providing an image comprised of image pixels; generating a belief map corresponding spatially to the image pixels, wherein the belief map includes belief values indicating the likelihood that respective pixels are representative of a particular material; generating an improvement parameter from the belief map, wherein the improvement parameter is applied uniformly to the image pixels; and using the improvement parameter to improve the characteristic of the image.
[0017] The present invention has the advantage that the global level of a particular characteristic of an image can be varied depending on the detected materials within the image. Where the characteristic is sharpness, rather than tuning a system to sharpen all images at a conservative level for fear of creating sharpening artifacts in some images, the system according to the present invention automatically determines the sharpening for each image, conservatively sharpening sensitive images and aggressively sharpening non-sensitive images. Specifically, the system of the present invention conservatively sharpens images in which human flesh is detected and aggressively sharpens images in which human flesh is not detected. In another aspect, the system according to the present invention conservatively reduces noise in areas of images where noise reduction can lead to objectionable artifacts, such as in images of vegetation, and aggressively reduces noise in images in which such sensitive material content is not detected.
[0018] These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a block diagram illustrating a technique for improving an image according to a first embodiment of the invention.
[0020] [0020]FIG. 2 is an example of the type of image processed according to the image improvement technique shown in FIG. 1.
[0021] [0021]FIG. 3 is an example of a belief map generated according to the image improvement technique shown in FIG. 1 for the image shown in FIG. 2 when the target material is human flesh.
[0022] [0022]FIG. 4 is a representation of a function g(z) used to determine a scale factor β for the image improvement technique shown in FIG. 1.
[0023] [0023]FIG. 5 is a representation of another function h(z) used to determine a scale factor β for the image improvement technique shown in FIG. 1.
[0024] [0024]FIG. 6 is a block diagram illustrating a technique for improving an image according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following description, an embodiment of the present invention will be described as a method implemented as a software program.
[0026] Those skilled in the art will readily recognize that the equivalent of such software may also be constructed in hardware. Because image enhancement algorithms and methods are well known, the present description will be directed in particular to elements forming part of, or cooperating more directly with, the method and system in accordance with the present invention. Other elements, and hardware and/or software for producing and otherwise processing the image signals, not specifically shown or described herein, may be selected from such materials, components and elements known in the art. Given the system and method as shown and described according to the invention in the following materials, software not specifically shown, described or suggested herein that is useful for implementation of the invention is conventional and within the ordinary skill in such arts.
[0027] Still further, as used herein, the computer program may be stored in a computer readable storage medium, which may comprise, for example, magnetic storage media such as a magnetic disk (such as a hard drive or a floppy disk) or magnetic tape; optical storage media such as an optical disc, optical tape, or machine readable bar code; solid state electronic storage devices such as random access memory (RAM), or read only memory (ROM); or any other physical device or medium employed to store a computer program.
[0028] A digital image is typically a two-dimensional array of numbers representing red, green, and blue pixel values or monochrome pixel values corresponding to light intensities. With regard to matters of nomenclature, the value of a pixel of a digital image located at coordinates (x,y), referring to the x th row and the y th column of a digital image, shall herein comprise a triad of values [r(x,y), g(x,y), b(x,y)] respectively referring to the values of the red, green and blue digital image channels at location (x,y). In this regard, a digital image may be considered as comprising a certain number of digital image channels. In the case of a digital image comprising red, green and blue two-dimensional arrays, the image comprises three channels, namely, red, green and blue spectral channels.
[0029] Referring initially to FIG. 1, a first embodiment of the present invention is illustrated for processing an image with a specific image processing path in order obtain an enhanced output image. In general, the present invention performs a shift invariant improvement to an image, the magnitude of the improvement being determined by the material content of objects within the image. Thus, the improvement applied to successive images may vary depending on the image content. The magnitude of the improvement applied to any particular image is selected in order to be appropriate for the image content. In the first embodiment shown in FIG. 1, the present invention performs a shift invariant sharpening to an image, the magnitude of the sharpening being determined by the objects within the image. Thus, the sharpening applied to successive images may vary depending on the image content, and the magnitude of the sharpening applied to any particular image is selected in order to be appropriate for the image content.
[0030] [0030]FIG. 1 illustrates an image i(x,y) having x o rows and y o columns that is input to an image subsampler 2 for reducing the number of pixels contained in the image and therefore decreasing the processing time required by the present invention to determine the sharpening parameter. Preferably, the image i(x,y) is of high resolution, for example, an illustrative high resolution image would have x o =1024 rows of pixels by y o =1536 columns of pixels. The image output from the image subsampler 2 is a low resolution image having m o rows and n o columns, for example, an illustrative low resolution image would have m o =128 and n o =192 pixels. The image subsampler 2 preferably performs a block averaging process over w×w pixel blocks (for example, w=8 (corresponding to the preceding illustrative examples)) in order to produce the low resolution image output from the image subsampler 2 . Many other methods of creating small images from larger images are known in the art of image processing and can be used as the image subsampler 2 . (The preceding examples are not intended as a limitation; in fact, the image subsampler may be omitted if the additional processing can be tolerated.)
[0031] The image output from the image subsampler 2 is then input to a material detector 4 for the creation of a belief map, indicating the belief that particular pixels or regions of pixels represent a given target material. The target material is selected as the material to which the image sharpening is sensitive. The material detector 4 outputs a belief map M(m,n), preferably having the same pixel dimensions in terms of rows and columns as the image input to the material detector 4 . The belief map indicates the belief that particular pixels represent the target material. The belief is preferably represented as a probability. For example, each pixel value M(m,n) is equal to 100*P(that pixel (m,n) of the low resolution image represents target material), where P(A) represents the probability of event A. Alternatively, each pixel value M(m,n) may represent a binary classification indicating belief. For instance, a pixel value of 1 in the belief map may represent the belief that the pixel represents the target material and a pixel value of 0 may represent the belief that the pixel does not represent the target material. In the preferred embodiment, the target material is human flesh. In commonly-assigned, copending U.S. Ser. No. 09/904,366, entitled “A Method for Processing a Digital Image to Adjust Brightness” and filed on Jul. 12, 2001 in the names of M. W. Dupin and J. Luo, a method is described of creating a belief map indicating the belief for a target material of flesh. Additionally, methods of creating belief maps for a target material of human flesh are described in the following articles: K. Cho, J. Jang, K. Hong, “Adaptive Skin-Color Filter,” Pattern Recognition, 34 (2001) 1067-1073; and M. Fleck, D. Forsyth, C. Bregler, “Finding Naked People,” Proceedings of the European Conference on Computer Vision , Vol. 2, 1996, pp. 592-602.
[0032] The method described in commonly-assigned, copending U.S. Ser. No. 09/904,366 that can be used for the regions of skin-tone can be summarized as follows. The pixel RGB values of an image are converted to “Lst” coordinates by the following equations:
L ( R+G+B )/ sqrt (3)
( R−B )/ sqrt (2)
t =(2 G−R−B )/ sqrt (6)
[0033] For each pixel in the input color digital image, the probability that it is a skin-tone pixel is computed. The probability is derived from its coordinates in the Lst space, based on predetermined skin-tone probability functions. These probability functions were constructed based on collection of data for the color-space distributions of skin and non-skin regions in a large collection of scene balanced images. The conditional probability that a pixel is a skin-tone pixel given its Lst coordinates is:
Pr (Skin| L,s,t )= Pr (Skin| L )* Pr (Skin| s )* Pr (Skin| t )
[0034] where each of the conditional distributions Pr(Skin|L), Pr(Skin|s), and Pr(Skin|t) are constructed by application of Bayes Theorem to the original training distributions for skin and non-skin pixels. Further details of this methodology can be found in the aforementioned commonly-assigned, copending U.S. Ser. No. 09/904,366, which is incorporated herein by reference. In comparison, there are other conventional methods for detecting skin-tone colored pixels, e.g., U.S. Pat. No. 4,203,671 (Takahashi) and U.S. Pat. No. 5,781,276 (Zahn) use the likelihood probability of P(color|Skin). However, one drawback of using the conventional likelihood probability is that the probability distribution of non skin-tone pixels is not accounted for. Consequently, there is a higher likelihood for false detection.
[0035] The collection of probabilities for all pixels forms a skin-tone probability distribution for the input image. The skin-tone probability distribution is thresholded to create a binary map such that each pixel is designated as either skin-tone or non skin-tone. Alternatively, a face detection algorithm can be initially used to find human face regions in the input color digital image. Thereupon, regions of skin-tone colors may be extracted from the detected face regions. For a description of a face detection method, see U.S. Pat. No. 5,710,833 by Moghaddam and Pentland (entitled “Detection, Recognition and Coding of Complex Objects Using Probabilistic Eigenspace Analysis”).
[0036] An example of the methodology is shown in FIGS. 2 and 3, where FIG. 2 shows an image of several people and FIG. 3 shows the associated belief map, when the target material is human flesh. The background 12 of the image is made up of the pixels having a belief of zero that the corresponding pixel in the low resolution image represents the target material (human flesh). If the material detector 4 detects that all pixels of the low resolution image have low probability of representing the target material, then the entire belief map will be background 12 (all zeros in the preferred encoding). FIG. 3 shows several regions made up of pixels having nonzero belief. For example, region 16 corresponds to a face in the low resolution image, and for example may have a high belief value of 95. Region 14 corresponds to an arm, and may have a belief value of 60. Region 18 incorrectly has a belief value of 40, indicating a belief that the tree branch may be human flesh. Such an incorrect belief value is a false positive. Generally, automatic detection algorithms such as the material detector 4 produce false positives such as region 18 as well as false negatives, (e.g. incorrectly classifying genuine flesh pixels as background 12 ).
[0037] Alternatively, the target material could be the material content of other types of objects in the image, such as human faces, sky, or any other material for which an automated method exists for determining material belief from an image. Human face detection is described in many articles, for example, see B. Heisele, T. Poggio, M. Pontil, “Face Detection in Still Gray Images,” MIT Artificial Intelligence Lab , Memo 1687, May 2000. In addition, commonly-assigned copending U.S. Ser. No. 09/450,190 (entitled “Method for Detecting Sky in Images” and filed Nov. 29, 1999 in the names of J. Luo and S. Etz) describes the creation of belief maps when the target material is blue sky.
[0038] The belief map is then input to a map analyzer 8 . The map analyzer 8 analyses the belief map and outputs the recommendation for the sharpening of the image as one or more sharpening parameters. A sharpening parameter is any parameter which directly relates to the level or strength of sharpening applied to an image. In the preferred embodiment, the map analyzer 8 outputs a scale factor β derived from an analysis of the belief map. In general, the sharpening parameters are a function of the belief map. In the preferred embodiment, the scale factor β is a function of the belief map M(m,n) and is preferably derived as follows: where:
β = ( β material - β non - material ) 001 max x , y M ( x , y ) + β non - material
[0039] wherein
[0040] β material is the ideal sharpening scale factor for images of the target material; and
[0041] β non-material is the ideal sharpening scale factor for images not containing the target material.
[0042] As previously mentioned, the target material is preferably human flesh. Therefore, β material is the ideal sharpening level for images containing flesh. Preferably, β material =1.5, and β non-material =5 because generally non-flesh images can be satisfactorily sharpened by greater amounts than images containing flesh. In this example, the scale factor β is determined based on the maximum belief of flesh contained in the belief map. Note that β material and β non-material may themselves be functions of characteristics of the image or the imaging system. For example, β material and β non-material may be decreased for high speed films because of grain.
[0043] Alternatively, the scale factor may be determined based on other characteristics of the belief map. For example, the scale factor β may be calculated based on the fraction of the belief map that has a specific belief. For example:
β= g ( z )
[0044] where:
z = 1 x o y o ∑ x , y M ( x , y ) ;
[0045] and
[0046] g(z) is a function used to convert the average value of the belief map into the scale factor β. An example of the function g(z) is shown in FIG. 4.
[0047] Alternatively, the scale factor may be determined based on other characteristics of the belief map. It has been observed that large flesh areas are most sensitive to the oversharpening because blemishes quickly become apparent.
[0048] However, when the flesh regions are small, generally the image can be sharpened more without the appearance of objectionable artifacts. As shown in FIG. 3, the preferred material detector 4 is described in the aforementioned commonly-assigned, copending U.S. Ser. No. 09/904,366, where Dupin and Luo return a belief map generally consisting of a background area 12 wherein all pixels have a value of 0 indicating the probability that the pixels represent the target material (human flesh) is estimated to be 0. Also, several foreground regions 14 , 16 , and 18 are shown wherein the belief map indicates a constant, non-zero belief that the pixels represent the target material for all pixels belonging to those regions. By using a connected component algorithm such as is well known in the art of image processing, each belief region having non-zero belief may be extracted from the belief map. In the example shown in FIG. 3, the size of region 16 is greater than the size of region 14 which is greater than the size of region 18 . The size of each belief region may be determined by any number of methods, including one of the several methods described herein. For instance, the size may be determined by counting the number of pixels belong to each belief region. Alternatively, (and preferably) the size may be determined by taking the product of the number of pixels belonging to each belief region and the associated value within the belief map of each belief region. The value of the sharpening parameter is then a function of the belief region sizes. For example,
β =h ( z )
[0049] where:
z = 1 x o y o max i R i ;
[0050] R i is the size of belief region i: and
[0051] h(z) is a function used to convert the average value of the belief map into the scale factor β. An example of the function h(z) is shown in FIG. 5.
[0052] The sharpening parameter(s) β determined by the map analyzer 8 is then input to a sharpener 10 . While in the present embodiment of the invention the sharpening parameter is the scale factor β, the function of the map analyzer 8 is without such limitation and other sharpness related determinations would be evident to those of ordinary skill in the art. For example, the filter used in the sharpening convolution performed by the sharpener 10 could be determined by the map analyzer 8 based on an analysis of the belief map.
[0053] The sharpener 10 inputs the sharpening parameter(s) and applies a sharpening algorithm to the image, utilizing the sharpening parameter(s) in order to produce an enhanced output image having improved sharpness without producing objectionable sharpness artifacts. In the preferred embodiment, the sharpener 10 applies an unsharp masking algorithm to the image using the determined value of β in order to produce the enhanced image. For example, sharpening an image according to the invention can be performed by use of the presently-described sharpening parameter(s) β in the aforementioned unsharp masking equation (1):
s ( x,y )= i ( x,y )** b ( x,y )+β f ( i ( x,y )− i ( x,y )** b ( x,y ))
[0054] where:
[0055] s(x,y)=output image with enhanced sharpness;
[0056] i(x,y)=original input image;
[0057] b(x,y)=lowpass filter;
[0058] f( )=fringe function;
[0059] ** denotes two dimensional convolution;
[0060] (x,y) denotes the x th row and the y th column of an image; and
[0061] β=the scale factor determined by the map analyzer 8 .
[0062] Those skilled in the art will recognize that there are several methods by which unsharp masking (such as provided by Eq. (1)) can be applied to a color image having multiple channels. For example, the unsharp mask process can be applied to each channel of the color image. Preferably, the unsharp mask process is applied in the following manner, commonly known in the art:
[0063] Assuming the input image is a color image consisting of red, green, and blue color channels, a matrix is first applied to the image in order to produce a luminance channel and two or more color difference channels. Next the unsharp mask process is applied to the luminance channel. Finally, an inverse matrix is applied to the several channels, generating an enhanced color image.
[0064] Additionally, the unsharp mask process may be applied to only a single image channel (e.g. the green channel), and the modified fringe data may be summed with each color channel in order to generate an enhanced color image. These and other similar modifications and enhancements to the unsharp mask process would be well understood by those of skill in this art. Since the particularities of their usage are not fundamentally related to the method of selecting sharpening parameters for a shift invariant sharpening, their particular application does not act to in any way limit the scope of the invention.
[0065] Those skilled in the art will also recognize that although Eq. (1) and the present invention generally describe the sharpening applied to the image as being performed by an unsharp mask, that is not necessarily the case. Assuming the fringe function f( ) of Eq. (1) is identity, the unsharp mask process can always be reconfigured as a single filter than can be applied with convolution to the image and produce results identical to the unsharp mask. For example, suppose the filter coefficients of b(x,y) are given as:
b ( x , y ) = [ 1 2 1 2 4 2 1 2 1 ] 16 .
[0066] Application of a filter c(x,y) with a convolution having coefficients given as
c ( x , y ) = [ 1 - β 2 ( 1 - β ) 1 - β 2 ( 1 - β ) 4 ( 1 + 3 β ) 2 ( 1 - β ) 1 - β 2 ( 1 - β ) 1 - β ] 16
[0067] will produce identical results compared with using filter b(x,y) in the unsharp mask of Equation (1). Such modifications to the preferred embodiment by the grouping of operations in the sharpener 10 such as can be determined by methods well known in algebra and digital signal processing will be evident to those of skill in this art and are within the scope of the present invention.
[0068] An alternative embodiment to the present invention is shown in FIG. 6. In this embodiment, a filter 20 is applied according to a parameter determined by the map analyzer 8 . The filter is applied uniformly across the image pixels, according to the filter parameter output from the map analyzer 8 . In this embodiment, the image characteristic is not sharpness and the filter is not a sharpening filter. Rather, the image characteristic is related to another type of improvement and the filter is another type of filter, for example the image characteristic is noise and the filter is a noise reduction filter. Noise reduction filters are well described in the art of image processing. For example, Jong-Sen Lee describes the sigma filter in the paper “Digital Image Smoothing and the Sigma Filter,” Computer Vision, Graphics, and Image Processing, 24, 255-269, 1983. The sigma filter replaces a central pixel of a neighborhood with all those pixels within Δ code values of intensity from the central pixel. The parameter Δ may be selected by the map analyzer 8 in a manner similar to the way that the parameter β was determined. The material content that is analyzed may be the same as that analyzed for sharpness, or it may be some other material content especially sensitive to noise. For example, when the target material is vegetation, the map analyzer 8 may output a small value of Δ for images containing regions having high belief and large value of Δ for images having no regions with high belief.
[0069] The present invention has been described with reference to a preferred embodiment. Changes may be made to the preferred embodiment without deviating from the scope of the present invention.
Parts List
[0070] [0070] 2 Image subsampler
[0071] [0071] 4 material detector
[0072] [0072] 8 map analyzer
[0073] [0073] 10 sharpener
[0074] [0074] 12 backgound region
[0075] [0075] 14 belief region
[0076] [0076] 16 belief region
[0077] [0077] 18 false positive belief region
[0078] [0078] 20 filter
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In a method of improving a characteristic of an image according to its material content, where the image is comprised of image pixels, a belief map corresponding spatially to the image pixels is generated. The belief map includes belief values indicating the likelihood that respective pixels are representative of a particular material, such as flesh. An improvement parameter is generated from the belief map, and the improvement parameter is applied uniformly to the image pixels to improve the characteristic, such as the sharpness, of the image.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a device used for protecting corners on walls from peeling wallpaper, chipping paint, and other damages sustained by people or other objects bumping or rubbing against corners of walls.
2. Prior Art
Many homes have corners that are adjacent to other rooms and since these corners are in general traffic patterns they are often brushed against or bumped, damage to wallpaper or paint will inevitably result. A current product on the market is a clear corner protector molded at a 90° angle at 8 foot lengths, but these are difficult to transport, not easily trimmed to fit and cannot protect corners that many new homes have. A lot of new construction contains corners of 45° in which case a 90° protector simply will not fit. According to my invention, I have discovered that a clear plastic strip with a "V" groove running along the center of the length of the strip can be easily transported, trimmed and folded. With my strip being divided along its length by a grooved area of reduced cross-sectional configuration a pair of flexible leaves are provided thus enabling my strip to be able to protect any angle corner from damage when applied to the corner.
SUMMARY OF THE INVENTION
The principal object of this invention is to provide transparent corner protection while maintaining convenient transportability, i.e. from a store to a home.
Another object of this invention is to provide corner protection on household or office corners that are other than 90°. Many newly constructed homes have angles of 45° in order to make more efficient use of space, and presently no device exists for protecting these corners embodying the advantageous features of my flat coilable, bendable protective strip for protecting finished corners.
A further object of this invention is to provide an improved coilable strip-type corner protector that when uncoiled can be more easily cut and trimmed to fit a corner shape. Currently a rigid 90° corner protector molded from plastic is being marketed that makes it somewhat difficult to trim to length to avoid certain obstacles like chair rails, etc.
The foregoing objects can be accomplished by providing a corner protector having a length of 8' that can be coiled and suitably secured in a circular coil form having a relatively small diameter such as 8"-10" or less depending on the thickness of the strip. This can be accomplished by coiling a strip of clear plastic with a "V" groove in the center providing flexible leaves that can flex about the groove for custom fitting to a variety of differently angled corners so that when it is ready to be installed it can be folded and then become rigid when attached to cover a corner to the walls defining the corner.
According to features of my invention, the strip has a "V" groove, and the strip can be folded along the "V" groove in either direction to accommodate any corner angle.
The strip is flat when first uncoiled, and scissors can be used to easily cut the length and any small section may be removed from the strip anywhere on its length.
According to important features of my invention I have provided a foldable translucent corner protector comprised of a flat strip of synthetic plastic, the cover protector having a V-shaped groove extending its length, the V-shaped groove dividing the strip and enabling the strip to be bent from a flat form along its length to provide a pair of bendable strip leaves for attachment to an angled wall surface of varying sized angles about a wall corner for protecting the wall corner, the leaves being joined together at the bottom of the V-shaped groove by a web, the web having a thickness of 1/64" or less
According to another feature of my invention I have provided a foldable translucent corner protector comprised of a length of a flat parallel sided strip of coilable semi-rigid polycarbonate having high impact strength and being translucent. The parallel sided strip being of uniform cross section along its length. The parallel sided strip being coilable with outer parallel sided strip edges in coiled pressing engagement with one another. The corner protector having a V-shaped groove extending along the length of the strip. The V-shaped groove dividing the strip and enabling the strip to be bent from a flat form along the length to provide a pair of bendable strip leaves bendable into right angled relationship to one another for attachment to a right angled wall surface for exposed protection to a wall corner. The leaves being joined together at the bottom of the V-shaped groove by a web. The leaves on opposite ends of the V-shaped groove being flush engaged with an outside surface of the wall corner.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a fragmentary side elevation of my strip after the strip has been uncoiled and is ready to be trimmed;
FIG. 2 is an end view of my plastic strip;
FIG. 3 is a fragmentary side elevation of my corner strip;
FIG. 4 is an end elevation showing the flexibility of my corner strip and showing some of the varying angles in which the corner protector can be folded;
FIG. 4a is an elevation of the strip shown in FIG. 4 only with the strip being folded in an opposite direction to provide a flat type corner where my corner protector is installed on a wider angled corner; and
FIG. 5 is an enlarged fragmentary exploded outside perspective view of my corner protector installed on a corner which corner is shown by phantom lines;
FIG. 6 shows the flexibility of my flat plastic strip while stored in a coiled position in readiness for use; FIG. 7 is an end view of a corner protector as shown in FIG. 4 showing the corner protector being bent so that the opposing sides of the groove are engaged against one another;
FIG. 8 is an end view of the corner protector as also shown in FIG. 4 which illustrates the corner protector in another position demonstrating how it would appear when installed on a right angled corner; and
FIG. 9 is a end view of the corner protector diagrammatically shown in FIG. 4 only showing the corner protector in an open position as it would be installed on a 50 degree corner.
DETAILED DESCRIPTION
As shown in the drawings, a preferred corner protection device or strip 10 is provided. In accordance with the present invention the clear synthetic plastic strip 10 is 11/2" wide with a "V" groove 11 running along the length of the strip. The "V" groove 11 is begun from a center of the strip and is continued up from such point at an angle greater than 45° in both upward and outward directions providing a pair of leaves 12 and 13 in order to accommodate both acute and obtuse angled corners. The strip 10 has opposite flat sides 21 and 22 which are parallel to one another. One side 21 is spaced from an apex or web 17 of the "V" groove 11 is 1/64" or less from the flat side 21 of the strip. This allows the apex or web 17 of the groove 11 to act as a hinge when folded as shown by the dotted and full lines in FIGS. 4 and 4a. The "V" groove has a pair groove surfaces 20.
The strip 10 is adapted to be mounted on a wall corner such as is shown in FIG. 5 at 14. The wall corner may have a base board 15 at its lower bottom edge. The strip 10 can be installed on the corner 14 by bending it in either position as shown in FIG. 4 and FIG. 4a depending on the angularity of the outside surface of the corner. In the illustrated embodiment, the corner is shown as a right angle corner and hence the strip 10 should be folded with its leaves positioned as shown in the full line position in FIG. 4 with the groove 11 being on the inside of the corner. When the strip 10 is thus folded, it can be secured to the wall corner by suitable means such as nails shown at 16 or by a suitable adhesive. The nails are sharp tipped and can be driven easily through the plastic to complete the attachment of the corner strip to the wall.
As will be observed in FIGS. 4 and 4a, the strip 10 when folded in the position shown by the full lines in FIG. 4 has a peaked or angled corner shown in a 90° position. Where the strip 10 is turned upside down so that the groove faces downwardly then the leaves 12 and 13 can be lifted to form what is identified here as a so called flat corner 18. The strip is folded to be provided with a flat corner in situations where the wall corner 14 has an angle of greater than 90°. In instances of this type, the groove 11 is disposed at the bottom at 18 as shown in FIG. 4a.
The flat flexible strip may be coiled up into a circular coil and secured by a sticky type tape or other suitable tie holding it in a coiled position allowing it to be easily placed into a shopping bag and transported in any automobile or cart. The parallel sided strip is coilable with outer parallel sided strip edges in coiled pressing engagement with one another. This flat flexible strip is shown in a coiled position in FIG. 6 and an adhesive plastic tape tie 19 as shown for securing the strip in a circular coil for easy handling by a consumer.
My corner strip can be preferably made from a semi-rigid polycarbonate since material of this type has high impact strength, and excellent translucency qualities. Further, semi-rigid polycarbonate material when used in strip form as shown at 10 in FIG. 1 can be easily trimmed and coiled as shown in FIG. 6. My strip is preferably extruded so that mold lines can be avoided whereby the strip will have unmarked surfaces. Since most floor to ceiling distances are approximately 8 feet it is contemplated that these strips should be marketed in 8 foot lengths. Where the strip 10 is coiled, it can be preferably coiled into a 10 inch diameter circle to reduce any spring when a strip is uncoiled all as shown in FIG. 6.
The preferred embodiment of my strip has a thickness of 1/16 inch with a webbed thickness of 1/64 inch. Wider strips may be used to cover more area further from a wall corner but I have found the preferred width to be 11/2 inches. The V-shaped groove 11 is intended to have an angle of greater than 45°. As has been noted previously, the strip can be used with the groove 11 either side out when installed on a corner 14. As mentioned before, the strip can be attached by the nails 16 or can be secured by an acrylic adhesive, if desired.
The basic and novel characteristics of the improved apparatus of the present invention will be readily understood from the foregoing disclosure by those skilled in the art. It will become readily apparent that various changes and modifications may be made in the form, construction and arrangement of the improved apparatus of the present invention as set forth hereinabove without departing from the spirit and scope of the invention. Accordingly, the preferred and alternative embodiments of the present invention set forth hereinabove are not intended to limit each spirit and scope in any way.
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A foldable translucent corner protector comprised of a flat strip of synthetic plastic, the corner protector having a V-shaped groove extending its length, the groove having a depth of 1/64" or less the V-shaped groove dividing the strip and enabling the strip to be bent from a flat form along its length to provide a pair of bendable strip leaves for attachment to an angled wall surface of varying sized angles about a wall corner for protecting the wall corner.
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FIELD OF THE INVENTION
The present invention relates to a composite toothpaste product containing a fluorine compound and a hydroxyapatite in combination. In particular, the invention relates to an improved composite toothpaste product which imparts favorable effects to teeth by way of the activity of the fluorine compound as well as the activity of the hydroxyapatite, when the teeth are brushed.
BACKGROUND OF THE INVENTION
The toothpaste generally comprises water, a wetting agent, and an abrasive. Until now, proposals to incorporate a variety of additives into the toothpaste for improving functions of the toothpaste have been made. Some of these proposals have been employed in the production of commercially available toothpastes.
A representative additive is a fluorine compound. It has been confirmed that a fluorine compound is dissociated in an aqueous toothpaste to give a fluorine ion which reacts with a surface layer of the tooth to enhance the surface hardness of the tooth. A toothpaste containing a fluorine compound is described in Japanese Patent Provisional Publication No. 46-4150.
Recently, incorporation of a hydroxyapatite having the same chemical composition as that of the tooth into a toothpaste has been studied. The incorporation of a hydroxyapatite is described in Japanese Patent Provisional Publications No. 55-57514, No. 56-73014, No. 56-73015, No. 60-206678, No. 61-91333, and No. 57-185213. Since the hydroxyapatite has the same chemical composition as that of tooth, it has a high affinity to the tooth and can be attached to a defective portion of tooth produced by dental caries when it is incorporated into a toothpaste. Further, the hydroxyapatite is effective for removing a bacterial plaque attached to the tooth. For these reasons, a toothpaste containing a hydroxyapatite is commercially available.
As described above, each of a fluorine compound and a hydroxyapatite imparts to a toothpaste an additional performance. Therefore, it has been studied to incorporate both chemicals in combination into toothpastes. It has been noted, however, that a fluorine compound is highly reactive to a hydroxyapatite and the incorporation both chemicals into a toothpaste causes a reaction between them to produce a fluorinated apatite or a calcium fluoride which is very hard. Accordingly, the performances of the both chemicals cannot be utilized in the toothpaste.
Japanese Patent Provisional Publication No. 58-219107 proposes to prepare a fluorine ion source and a calcium ion source (no hydroxyapatite is mentioned) separately and to utilize them sequentially or simultaneously when teeth are brushed.
Japanese Patent Provisional Publication No. H1-6213 (which corresponds to Japanese Patent Publication (examined) No. H2-31049) discloses a toothpaste which comprises microcapsules containing a hydroxyapatite (or a fluorine compound) and a supporting material containing a fluorine compound (or a hydroxyapatite) in which the microcapsules are dispersed.
The present inventors studied these known composite toothpaste products and noted that these products hardly give to the toothpastes the target combined effects. In more detail, the composite toothpaste product of Japanese Patent Provisional Publication No. 58-219107 requires two toothpastes which should be encased in different vessels and which are necessarily employed in combination when teeth are brushed. In the microcapsuled toothpaste of Japanese Provisional Publication H1-6213, the wall of the microcapsule is sometimes not enough for reliably separating the fluorine compound from the hydroxyapatite, and therefore the reaction between both chemicals possibly proceeds during storage of the toothpaste product. If the wall of the microcapsule has an increased thickness, the reaction is effectively obviated. In that case, however, the microcapsules are hardly broken in the brushing procedure and the performance of the microcapsuled chemical is hardly utilized.
Further studies by the present inventors have revealed that when a fluorine compound and a hydroxyapatite are simultaneously employed in the teeth brushing procedure and the fluorine compound is first brought into contact with teeth, the teeth rapidly react with the fluorine compound to form a hard surface layer thereon and hence the desired contact of the hydroxyapatite to the teeth is disturbed. Moreover, it has been noted that a fluorine compound is preferably brought into contact with teeth after the teeth are covered with a hydroxyapatite so that the effect of hardening tooth surface to be provided by a fluorine compound can not be attained.
SUMMARY OF THE INVENTION
The present invention resides in a composite toothpaste product comprising a toothpaste containing a hydroxyapatite as a main active ingredient and another toothpaste containing a fluorine compound as a main active ingredient, which are enclosed with a container but separated from each other by a partition united to the container, under the condition that these toothpastes are separated from each other with no contact when it is out of use, and are squeezed out of the container, when in use, in such a manner that the latter toothpaste is enclosed with the former toothpaste.
The above-mentioned composite toothpaste product of the invention preferably has such a structure that the container comprises double tubes in which one is an outer flexible tube having one open end and another is an inner flexible tube having one open end, the open end of the inner tube being put back from the position of the open end of the outer tube in the longitudinal direction of the tubes, the toothpaste containing a fluorine compound being placed in the inner tube, and the toothpaste containing a hydroxyapatite being placed in a space formed between the inner tube and the outer tube.
In the invention, the hydroxyapatite is preferably contained in the toothpaste containing an hydroxyapatite in an amount of 1 to 30 weight %, based on the total amount of the toothpaste containing an hydroxyapatite and the toothpaste containing a fluorine compound, and the fluorine compound is preferably contained in the toothpaste containing a fluorine compound in an amount of 0.002 to 2.0 weight % in terms of an amount of fluorine ion, based on the total amount of the toothpaste containing an hydroxyapatite and the toothpaste containing a fluorine compound. It is also preferred that the fluorine compound is contained in the toothpaste containing a fluorine compound in an amount of 0.001 to 3.0 weight % in terms of an amount of fluorine ion, based on the amount of the hydroxyapatite contained in the toothpaste containing an hydroxyapatite.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic section of a representative composite toothpaste product according to the invention.
FIG. 2 is a section of the toothpaste product of FIG. 1, taken along I—I line.
FIG. 3 schematically illustrates a section of a toothpaste having been pushed out of the container.
DETAILED DESCRIPTION OF THE INVENTION
The composite toothpaste product of the invention is further described by referring to the attached drawings.
FIG. 1 is a schematic view of a section indicating a representative structure of the composite toothpaste product of the invention which utilizes a cylindrical double tube 11 made of flexible material. FIG. 2 is a section of the toothpaste product of FIG. 1, taken along I—I line. The cylindrical double tube 11 comprises an outer tube 12 and a coaxially arranged inner tube 13 , both of which are made of a flexible sheet such as a metal sheet. The open end (for pushing out one toothpaste) of the inner tube 13 is put back from the open end (for pushing out another toothpaste) of the outer tube 12 . In the inner tube 13 , a fluorine toothpaste 14 (i.e., a toothpaste containing a fluorine compound) is contained. Between the inner tube 13 and the outer tube 12 , a hydroxyapatite toothpaste 15 (i.e., a toothpaste containing a hydroxyapatite) is placed.
In carrying out tooth-brushing, a pressure is applied to the side surfaces of the toothpaste product of the invention in the conventional manner. The outer hydroxyapatite toothpaste 15 is first pushed out, and subsequently the inner fluorine toothpaste 14 is pushed out in such a manner that the fluorine toothpaste is enclosed with the hydroxyapatite toothpaste. When the pressure is removed, the pushed-out toothpastes are separated from the tubes under the condition that the end of the pushed-out fluorine toothpaste 14 is also enclosed with the pushed-put hydroxyapatite toothpaste 15 , as is schematically illustrated in FIG. 3 .
The combined toothpastes illustrated in FIG. 3 are placed on a toothbrush, and brought into contact with teeth. Accordingly, the hydroxyapatite toothpaste 15 is first brought into contact with teeth, and the fluorine toothpaste 14 is subsequently brought into contact with teeth which are already treated with the hydroxyapatite toothpaste. Therefore, the functions of the hydroxyapatite, that is, plugging defective tooth portions and removing bacterial plaque, are effectively realized, and then the tooth surface which is repaired and coated by hydroxyapatite is hardened by action of a fluorine ion.
The composition of the composite toothpaste product of the invention is described below in more detail.
The fluorine toothpaste contains as an active ingredient a fluorine compound which releases a fluorine ion in water. The fluorine compound can be sodium mono-fluorophosphate which is generally employed in tooth pastes. However, a fluorine compound having a higher activity, such as sodium fluoride, is preferably employed in the invention. A fluorine compound having such a high activity is apt to cause troubles during storage of toothpastes containing such fluorine compound and in the tooth brushing procedure.
In contrast, the composite toothpaste product of the invention comprises a fluorine-containing toothpaste and a hydroxyapatite-containing toothpaste which are well separated from each other. In the tooth-brushing procedure, the hydroxyapatite-containing toothpaste is first brought into contact with teeth for pre-treatment.
Therefore, the highly active fluorine compound is stably stored and functions safely in the tooth-brushing procedure.
A variety of compositions are known for formulating fluorine-containing toothpastes. Further known are various additional ingredients and additives as well as amounts of these chemicals. These known chemicals and technology are utilizable for formulating the fluorine-containing containing toothpaste to be employed in the invention.
Also known is a hydroxyapatite for incorporation into toothpastes. A variety of compositions are also known for formulating hydroxyapatite-containing toothpastes. Further known are various additional ingredients and additives as well as amounts of these chemicals. These known chemicals and technology are utilizable for formulating the hydroxyapatite-containing toothpaste to be employed in the invention. The hydroxyapatite preferably has a particle size (a size of a primary particle) of not more than 5.0 μm, more preferably in the range of 0.01 to 1.0 μm. The specific surface area preferably is in the range of 10 to 100 m 2 /g.
There are no specific limitations with respect to material to be used for the preparation of the containers of the composite toothpaste product according to the invention. In consideration of the daily tooth-brushing procedure, however, the double tube structure illustrated in FIG. 1 and FIG. 2 is preferred. The containers are also preferred to be produced by a flexible sheet such as a metal film or a laminate of a metal film and a plastic resin film.
EXAMPLE 1
(1) Toothpaste Containing Fluorine Compound as Active Ingredient
Aluminum hydroxide
15
wt. %
Silicic acid anhydride
7
wt. %
Alumina
2
wt. %
Glycerol
15
wt. %
Sorbitol
15
wt. %
Carboxymethylcellulose
2
wt. %
Sodium laurylsulfate
2
wt. %
Sodium fluoride
0.1
wt. %
Flavor
1
wt. %
Pure water
40.9
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a fluorine-containing toothpaste.
(2) Toothpaste Containing Hydroxyapatite as Active Ingredient
Hydroxyapatite
15
wt. %
Calcium hydrogen phosphate (2H 2 O)
20
wt. %
Glycerol
10
wt. %
Sorbitol
10
wt. %
Carboxymethylcellulose
1
wt. %
Sodium laurylsulfate
2
wt. %
Saccharin sodium salt
0.1
wt. %
Flavor
1
wt. %
Pure water
40.9
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a hydroxyapatite-containing toothpaste.
(3) Composite Toothpaste Tube
The fluorine-containing toothpaste and the hydroxyapatite-containing toothpaste prepared above were placed in a ratio of 1:3 in a double tube vessel illustrated in FIGS. 1 and 2 under the condition that the former was placed in the inner tube and the latter was placed in the space between the inner tube and the outer tube.
(4) Evaluation of Toothpastes for Increase of Whiteness
1) Fifteen adults (including males and females) were divided into three groups in which each group had five adults. The adults in each group daily performed tooth-brushing twice a day (3 minutes for each brushing) for three days using one of the below-mentioned toothpastes.
Group A: the composite toothpaste product prepared in (3) above
Group B: a commercially available hydroxyapatite-containing toothpaste
Group C: a commercially available fluorine compound-containing toothpaste
After the three day-brushing procedures, whiteness of front teeth at the both first positions on the upper jaw was measured by means of a color-difference meter.
2) Results of Evaluation (Increase of Whiteness)
The results of evaluation are set forth in Table 1 in terms of whiteness value, which are shown by a mean value±standard deviation.
TABLE 1
Group A
Group B
Group C
Before brushing
52-65
51-72
49-66
Increase of
10 ± 2
4 ± 2
1 ± 1
whiteness
Remarks: Whiteness of standard white board = 97 ± 1 Whiteness of white paper = 91 ± 1
The results indicate that prominent increase of whiteness is observed when the tooth-brushing is performed using the composite toothpaste product of the invention.
(5) Evaluation of Toothpastes for Removing Bacterial Plaque
1) The same fifteen adults (including males and females) as above were divided into three groups in which each group had five adults. The amount of bacterial plaque attached to teeth of the adults in each group were measured using a dye after a breakfast was taken. Subsequently, the adults performed tooth-brushing using one of the below-mentioned toothpastes.
Group A: the composite toothpaste product prepared in (3) above
Group B: a commercially available hydroxyapatite-containing toothpaste
Group C: a commercially available fluorine compound-containing toothpaste
After the brushing was complete, the amount of bacterial plaque attached to teeth of the adults was measured using a dye in the same manner to give a plaque index which indicated the effect of toothpaste for removing bacterial plaque.
2) Results of Evaluation (Removal of Bacterial Plaque)
The results of evaluation are set forth in Table 2 in terms of plaque index, which are shown by a mean value±standard deviation.
TABLE 2
Group A
Group B
Group C
Before brushing
0.57 ± 0.47
0.55 ± 0.49
0.60 ± 0.51
After brushing
0.08 ± 0.11
0.12 ± 0.10
0.15 ± 0.11
The results indicate that marked removal of bacterial plaque is observed when the tooth-brushing is performed using the composite toothpaste product of the invention.
(6) Evaluation of Toothpastes for Inhibition of Dental Caries
1) Thirty children of 10 to 12 age (including boys and girls) were divided into three groups in which each group had ten children. The children in each group daily performed tooth-brushing twice a day (morning and night) for six months using one of the below-mentioned toothpastes.
Group A: the composite toothpaste product prepared in (3) above
Group B: a commercially available hydroxyapatite-containing toothpaste
Group C: a commercially available fluorine compound-containing toothpaste
After the six month-brushing procedures, approximately 7 permanent teeth of each child were observed in each group to count a number of teeth newly having dental caries, and NCIR (new caries incidence rate) was calculated.
2) Results of Evaluation (Inhibition of Dental Caries)
The results of evaluation are set forth in Table 3 in terms of number of teeth having new dental caries and NCIR value.
TABLE 3
Group A
Group B
Group C
Number of teeth
2/73
4/71
6/76
having new
dental caries
NCIR
2.7%
5.6%
7.9%
The results indicate that marked effect for inhibition of dental caries is observed when the tooth-brushing is performed using the composite toothpaste product of the invention.
EXAMPLE 2
1) Toothpaste Containing Fluorine Compound as Active Ingredient
Aluminum hydroxide
10
wt. %
Silicic acid anhydride
3
wt. %
Alumina
3
wt. %
Silica
10
wt. %
Sodium chloride
10
wt. %
Glycerol
10
wt. %
Sorbitol
10
wt. %
Carboxymethylcellulose
1
wt. %
Sodium laurylsulfate
2
wt. %
Sodium monofluorophosphate
0.5
wt. %
Flavor
1
wt. %
Pure water
39.5
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a fluorine-containing toothpaste.
(2) Toothpaste Containing Hydroxyapatite as Active Ingredient
Hydroxyapatite
3
wt. %
Calcium hydrogen phosphate (2H 2 O)
37
wt. %
Glycerol
10
wt. %
Sorbitol
10
wt. %
Carboxymethylcellulose
1
wt. %
Sodium laurylsulfate
2
wt. %
Saccharin sodium salt
0.5
wt. %
Flavor
1
wt. %
Pure water
35.5
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a hydroxyapatite-containing toothpaste. available toothpastes containing a hydroxyapatite or a fluorine compound.
Hydroxyapatite
7
wt. %
Calcium hydrogen phosphate (2H 2 O)
33
wt. %
Glycerol
10
wt. %
Sorbitol
10
wt. %
Carboxymethylcellulose
1
wt. %
Sodium laurylsulfate
2
wt. %
Saccharin sodium salt
0.3
wt. %
Flavor
1
wt. %
Pure water
35.7
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a hydroxyapatite-containing toothpaste.
(3) Composite Toothpaste Tube
The fluorine-containing toothpaste and the hydroxyapatite-containing toothpaste prepared above were placed in a ratio of 1:4 in a double tube vessel illustrated in FIGS. 1 and 2 under the condition that the former is placed in the inner tube and the latter is placed in the space between the inner tube and the outer tube.
(4) Evaluation of Toothpastes
The composite toothpaste product of the invention prepared in (3) above showed excellent results in the increase of whiteness, removal of bacterial plaque, and inhibition of dental caries, which were comparable to the results observed in Example 1.
Possibility in Industrial Use
The composite toothpaste product of the invention show, when it is employed in tooth-brushing, an excellent effect in increase of whiteness, removal of bacterial plaque, and inhibition of dental caries, which is more effective in tooth-brushing using the conventionally
(3) Composite Toothpaste Tube
The fluorine-containing toothpaste and the hydroxyapatite-containing toothpaste prepared above were placed in a ratio of 1:3 in a double tube vessel illustrated in FIGS. 1 and 2 under the condition that the former was placed in the inner tube and the latter was placed in the space between the inner tube and the outer tube.
(4) Evaluation of Toothpastes
The composite toothpaste product of the invention prepared in (3) above showed excellent results in the increase of whiteness, removal of bacterial plaque, and inhibition of dental caries, which were comparable to the results observed in Example 1.
EXAMPLE 3
(1) Toothpaste containing Fluorine Compound as Active Ingredient
Light calcium carbonate
10
wt. %
Aluminum hydroxide
10
wt. %
Silicic acid anhydride
12
wt. %
Alumina
3
wt. %
Glycerol
15
wt. %
Sorbitol
10
wt. %
Carboxymethylcellulose
2
wt. %
Sodium laurylsulfate
2
wt. %
Sodium monofluorophosphate
0.3
wt. %
Flavor
1
wt. %
Pure water
34.7
wt. %
The above-mentioned ingredients were mixed and kneaded in the conventional manner to prepare a fluorine-containing toothpaste.
(2) Toothpaste Containing Hydroxyapatite as Active Ingredient
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A composite toothpaste product comprising a toothpaste containing a hydroxyapatite as a main active ingredient and another toothpaste containing a fluorine compound as a main active ingredient, which are enclosed with a container made of, for instance, a flexible tube but separated from each other by a partition united to the container. In the composite toothpaste product, the toothpastes are separated from each other with no contact when it is out of use, and are squeezed out of the container, when in use, in such a manner that the latter toothpaste is enclosed with the former. It is far more effective in removing bacterial plaque, improving tooth whiteness, and preventing dental caries than the conventional toothpaste products containing only either a hydroxyapatite or a fluorine compound.
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This is a divisional of application Ser. No. 08/704,919 filed on Aug, 30, 1996 now U.S. Pat. No. 5,745,938.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to rescue boards that are constructed of several individual pieces. Such structures of this type, generally, allow the rescue personnel to extricate an unconscious or injured person from a confined space through a small opening and onto a backboard for transport to a medical facility.
2. Description of the Related Art
It has come to the attention of the present inventors that when attempting to rescue an unconscious or injured person from a confined space having a small opening, standard equipment will not go through the small hole. Consequently, this requires that the unconscious person be raised to the level of the small hole. This, typically, requires at least four individuals to raise the person and work the individual through the hole. However, due to the opening size, the number of people that could enter the confined space through the small hole is limited. Also, Occupational Safety and Health Administration (OSHA) regulations prohibit persons from entering a confined space for a rescue to only trained rescue personnel.
It is also known, in body restraint devices of the board-type, to employ different techniques and apparatus for the purpose of securing a patient to the board for transportation to a medical facility. Exemplary of such prior art are U.S. Pat. No. 2,675,564 ('564) to R. C. Hughes, entitled "Stretcher", U.S. Pat. No. 4,259,950 ('950) to A. P. Klippel, entitled "Extrication Backbrace", and U.S. Pat. No. 4,506,664 ('664) to R. A. Brault, entitled "Spineboard". While these devices are made for the purpose of securing a patient to the board for transportation to a medical facility, these devices would not be able to be used to extricate an unconscious or injured person from a confined space through a small opening and onto a backboard for subsequent transport to the medical facility. Therefore, a more advantageous device, then, would be presented if the device could be used in a confined space having a small opening.
It is apparent from the above that there exists a need in the art for a rescue board which is light weight through simplicity of parts and uniqueness of structure, and which at least equals the securing techniques of the known rescue devices, but which at the same time is capable of being used to extricate an unconscious or injured person from a confined space having a small opening. It is the purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
Generally speaking, this invention fulfills these needs by providing a rescue board for extricating an unconscious or injured patient from a confined space through a small opening, comprising: a rigid lower assembly means for assisting in lifting and retaining the patient; and a rigid upper assembly holding means hingedly attached to the lower assembly means and capable of being secured to an area substantially adjacent to the small opening.
In certain preferred embodiments, the patient retaining means includes a patient guiding means. Also, the holding means includes a patient guiding means. Finally, the securing means includes a U-shaped connection for securing the rescue board.
In another further preferred embodiment, the rescue board of the present invention allows for the extrication of an unconscious or injured person from a confined space through a small opening and onto a backboard for subsequent transport to a medical facility.
The preferred rescue board, according to this invention, offers the following advantages: lightness in weight; ease of assembly; good stability; good durability; good economy; high strength for safety; and excellent extrication characteristics. In fact, in many of the preferred embodiments, these factors of lightness in weight, ease of assembly, stability, strength and extrication are optimized to the extent that is considerably higher than heretofore achieved in prior, known body restraint devices.
The above and other features of the present, invention, which will become more apparent as the description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying drawings, wherein like characters represent like parts throughout the several views and in which:
A BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a lower portion of a rescue board, according to the present invention;
FIG. 2 is a side plan view of the lower portion of the rescue board, taken along lines 2--2 of FIG. 1, according to the present invention;
FIG. 3 is a top plan view of an upper portion of the rescue board, according to the present invention;
FIG. 4 is a side view of the upper portion of the rescue board, taken along lines 4--4 of FIG. 3, according to the present invention;
FIG. 5 is a schematic illustration of the rescue board, according to the present invention, being located within a confined space and the unconscious or injured person being placed upon the rescue board; and
FIG. 6 is a schematic illustration of the unconscious or injured person being elevated within the confined space such that the person can be extricated from the confined space.
DETAILED DESCRIPTION OF THE INVENTION
With reference first to FIG. 1, there is illustrated a lower rescue board assembly 50. It is to be understood that lower assembly 50 and upper assembly 100 (FIGS. 3 and 4) are part of rescue board 2 (FIGS. 5 and 6). However, in order to avoid further confusion, lower assembly 50 will now be discussed.
Lower assembly 50 includes, in part, plate 52, patient supports 54, structural rails 56, and hinge plate 58. Preferably, elements 52, 54, 56 and 58 are constructed of any suitable metallic material, such as, aluminum. It is also to be understood that plate 52, preferably, should be long enough to support at least the average build of a human being.
With respect to FIG. 2, elements 54, 56 and 58 can be seen more clearly. Also, conventional holes 60 in hinge plate 58 can be more clearly seen. Preferably, elements 54 and 58 are attached to plate 52 by any suitable metal attaching techniques, such as, welding.
As discussed earlier, rescue board assembly 2 also includes upper assembly 100. As more clearly seen in FIG. 3, upper assembly 100 includes, in part, plates 102 and 104, U-shaped connections 105, supports 106, step 108, and hinge plate 110. Preferably, elements 102, 104, 105, 106, 108 and 110 are constructed of any suitable metallic material, such as, stainless steel.
With respect to FIG. 4, elements 102, 106 and 110 can be more clearly seen. Also, conventional hinge holes 112 can be seen on hinge plate 110. Also, it is to be understood that elements 102, 104, 105, 108 and 110, can be attached to each other by any suitable conventional metal attaching techniques, such as, welding.
During the operation of rescue board assembly 2, an injured or unconscious patient 204 is located within a confined space 200. Two individuals (not shown) enter into confined space 200 through small opening 202 and place rescue board assembly 2 within confined space 200 such that lower assembly 50 is located within confined space 200 and upper assembly 100 is located adjacent to small opening 202. Lower assembly 50 is located at approximately a 20 degree angle from the bottom of confined space 200. It is to be understood that if the lower assembly cannot touch the bottom of confined space 200, suitable stops (not shown) can be added to assembly 2 by conventional techniques to still achieve the desired angle. Lower assembly 50 is secured to the outside by upper assembly 100 and U-shaped connections 105. In particular, a rope or other such suitable device is attached to U-shaped connections 105 and another stable connection (not shown) such that rescue board assembly 2 will not substantially move. It is to be understood that hinge 150 includes hinge plate 58 (FIGS. 1 and 2) and hinge plate 110 (FIGS. 3 and 4).
Conventional restraining devices (not shown) are placed upon the wrists of patient 204 and fed through opening 202 to the outside of confined space 200. Individuals (not shown) outside of confined space 200 pull on the restraining devices (not shown) and patient 204 is guided onto lower assembly 50 until the head of patient 204 is located near supports 54 and the hands of patient 204 are located outside of small opening 202.
As shown in FIG. 6, once the head of patient 204 is located adjacent to supports 54 and the arms of patient 204 are located outside of small opening 202, lower assembly 50 is raised level with small opening 202 by rescue team members (not shown) inside of confined space 200. In this raised position, one individual is able to hold assembly 50 level and another individual is able to pull patient 204 along lower assembly 50 and upper assembly 100 through small opening 202 onto a conventional backboard 250 for subsequent transport to a medical facility.
Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims.
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This invention relates to rescue boards that are constructed of several individual pieces. Such structures of this type, generally, allow the rescue personnel to extricate an unconscious or injured person from a confined space through a small opening and onto a backboard for transport to a medical facility.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application No. 61/260,171, entitled Air Intake Apparatus, filed on Nov. 11, 2009, the entire contents of which is hereby expressly incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to an air intake duct for an internal combustion engine that is capable of dissipating pressure waves in an intake duct for reducing the noise created by the induction of air.
BACKGROUND OF THE INVENTION
The air induction passageway of an internal combustion engine (ICE) will create a significant amount of noise as the air is drawn into the intake of the induction passageway and conveyed to the inlet of the engine. A typical induction passageway generally includes an air inlet, an air filter or cleaner and passageways or ducts that serve to connect the inlet, and the air cleaner with the intake of the internal combustion engine. The noise generated by an internal combustion engine when installed in a passenger vehicle is a very undesirable attribute. A consumer's comfort and driving experience is often a determinative factor when it comes to the purchase of an automobile or any other type of vehicle. Several attempts have been made to mute or negate these unwanted sounds emanating from the engine compartment of a motor vehicle. Several attempts have included sound attenuating devices incorporated into the air induction system, such as a resonator or muffler. The space within a vehicle's engine compartment is somewhat limited and must be utilized in a judicious manner. Many of these devices by their very nature consume large quantities of precious space that can result in the redesign or removal of other critical components typically located within the engine compartment.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 6,517,595, to Kino et al, discloses an intake duct for introducing outside air into an air cleaner of an internal combustion engine. It includes a hollow duct body with an opening and a piece of non-woven fabric formed in a flat shape, and is joined to the duct body to close the opening. The duct body includes a circumferential wall formed of a resin, and the opening is formed along a plane extending through a portion of the circumferential wall. The piece of non-woven fabric is fixed to the duct body so that some of the resin of the duct body penetrates into the non-woven fabric.
U.S. Pat. No. 6,553,953, to Fujihara discloses at least a part of a duct wall of a suction duct that is formed out of a molded body of non-woven fabric. The non-woven fabric contains a thermoplastic resin binder.
U.S. Pat. No. 6,622,680, to Kino et al, discloses an opening formed in a longitudinal direction in a duct wall. The entire opening is covered with non-woven fabric, and the lateral width of the opening is set to be not shorter than 1/20 of the circumferential length of the duct wall. Alternatively, a porous member is thermally welded with the head of an opening of a small cylindrical portion projecting from the duct wall of a duct body, while the duct body is prevented from deformation. In a method for manufacturing the air intake duct, a high-melting molded piece is brought into contact with a hot plate so as to be heated. A low-melting molded piece is disposed at a distance from the hot plate so as to be heated by radiation heat from the hot plate.
U.S. Pat. No. 6,877,472, to Lepoutre, discloses an intake duct for taking air into an internal combustion engine, notably the engine of an automobile. The duct includes a first wall made of a porous material, wherein a film is implemented which is sufficiently thin thereby avoiding any incidence upon the acoustical characteristics. It has a surface mass of less than 100 grams per square meter. The film is fixed onto the porous wall such that at least 50% of the surface of the film facing the porous wall is not fixed thereto.
U.S. Pat. No. 6,959,678, to Kino et al, discloses a method for making an air intake apparatus. The method includes a holding-portion forming step, a temporary fixing step, and a joining step. In the holding-portion forming step, a holding portion is formed. In the temporarily fixing step, the porous member is held by the holding portion. In the joining step, the holding portion and the porous member are joined together. In the air intake apparatus manufactured by this manufacturing method, a peripheral portion of the porous member is doubly sealed with the holding portion that is an outer edge part of the opening. Consequently, the opening is reliably covered with the porous member so that intake noise is reliably reduced.
U.S. Pat. No. 7,107,959, to Kino et al, discloses an air intake apparatus for suppressing noise. An opening is provided at a part of the intake walls corresponding to an antinode region of resonance mode of standing wave in a full length of the intake path, or at a part of noise pressure level being high in the intake path. The opening is closed with a permeable member and a noise insulating wall is disposed outside the permeable member for suppressing emission of transmitting noise passing through the permeable member. Alternatively, a vibration control member for suppressing face-vibration of the permeable member and reducing radiant noise from the permeable member is provided instead of the noise insulating wall.
U.S. Pat. No. 7,086,365, to Teeter, discloses a composite air intake manifold having a header and runners with communicating passages. The composite intake manifold is fashioned from carbon fiber cloth which is preferably impregnated with resin and cured between a meltable core mold and a split outside mold. The carbon fiber cloth is oriented throughout the manifold to give the manifold maximum pressure resisting capability with minimum thickness and weight. Because virtually any shape may be adopted for the interior passages of the header and the runners, the interior passages of the header and runners may be shaped to enhance air flow through the manifold.
U.S. Pat. No. 7,191,750, to Daly et al, discloses an intake manifold assembly including an inner shell that is inserted into an outer shell, and a cover that seals the open end of the outer shell. The inner shell includes dividers that form air passages. A laser device is traversed along the outer surface of the outer shell along a path which corresponds with the inner shell to form a laser weld joint. The intake manifold assembly of this invention includes features and methods of assembly that improve the laser weld joints utilized to assemble the plastic intake manifold assembly.
U.S. Pat. No. 7,207,307, to Ino et al, discloses an intermediate resin molded body that is put between two outer resin molded bodies, and a molten resin is injected substantially simultaneously into a first interface between one outer resin molded body of the two outer resin molded bodies and the intermediate resin molded body and a second interface between the other outer resin molded body and the intermediate resin body, so that the two outer resin molded bodies and the intermediate resin molded body are welded together.
U.S. Pat. No. 7,322,381, to Kino et al, discloses a duct main body which is formed into a hollow tubular shape having in an interior thereof an intake passageway for introducing outside air into an internal combustion engine by connecting integrally a plurality of divided bodies such as a first divided body and a second divided body which are formed of a thermoplastic resin and has, in a duct wall of the second divided body, an opening which establishes a communication between the inside and outside of the intake passageway. An air-permeable member is insert molded in the second divided body in such a manner as to cover the opening. The air-permeable member has, on an outer edge thereof, a joining portion which is impregnated with the thermoplastic resin. The second divided body has, in at least part of an inner peripheral edge of the opening, a vertical wall portion which protrudes outwards from the duct wall of the second divided body along an inner edge of the opening, and at least part of the joining portion of the air-permeable member is embedded in the vertical wall portion in such a manner as to be held therein in a thickness direction.
U.S. Pat. No. 7,475,664, to Jones et al, discloses an engine intake manifold assembly, including a first component having a first mating surface and a second molded plastic component having a second mating surface. The second molded plastic component is adhesively bonded to the first component with an adhesive. The adhesive bond strength exceeds the strength of the second molded plastic component.
U.S. Pat. No. 7,543,683, to Lewis et al, discloses a vehicle resonator structure including a resonator chamber that has a first intake tube and a first exhaust or outlet tube attached thereto. At least one of the tubes includes a projection that can be molded (e.g., via flash molding after the tube itself is blow molded) onto the tube. The resonator chamber can include upper and lower tube mount structures that can be hot plate welded and sandwiched onto the projection in the tube. Thus, the tube(s) is/are positively retained in position with respect to the resonator chamber such that the tuning of the resonator does not change due to fluctuations in geometry of the tube(s) and resonator chamber structure, and such that there is little or no vibration noise and/or possible damage that might result if the tube(s) were free to move with respect to the resonator chamber.
U.S. Publication No. 2004/0226531, to Kino et al, discloses an air intake apparatus including an air intake duct provided with an inlet through which intake air is introduced, an air cleaner disposed on the downstream side of the air intake duct for filtering the intake air, and an air cleaner hose disposed on the downstream side of the air cleaner and for supplying the filtered intake air to a combustion chamber of an engine, wherein an intake air passageway is laid out between the inlet and the combustion chamber. A passageway wall surrounding an antinode of a lower resonance mode corresponding to the whole passageway length of the intake air passageway, a valve for opening a communicating path allowing the inside of the intake air passageway to communicate with the outside thereof, at least when the lower resonance mode occurs, and an air-permeable member disposed to block the communicating path are disposed.
U.S. Publication No. 2004/0226772, to Hirose et al, discloses a permeable port constituted by an aperture and a porous member for covering an aperture that is provided in a part of an intake air passageway portion of an air intake apparatus. The permeable port is disposed in at least a part of a region between the central position of the whole length of an air intake duct and the central position of the whole length of the intake air passageway portion.
U.S. Publication No. 2004/0231628, to Jones et al, discloses an engine intake manifold assembly, including a first component having a first mating surface and a second molded plastic component having a second mating surface. The second molded plastic component is adhesively bonded to the first component with an adhesive. The adhesive bond strength exceeds the strength of the second molded plastic component.
SUMMARY OF THE INVENTION
The present invention is directed to an air intake duct for an internal combustion engine that is capable of suppressing the noise created by the induction of air. The air induction passageway includes an intake duct having an inlet and an outlet as well as an opening in a side wall located between the inlet and outlet. Mounted within this opening is a membrane formed from a woven acoustic material. The acoustic membrane reduces inlet snorkel noise by dissipating pressure waves in the duct. The acoustic membrane is formed from a woven material that allows sufficient air flow into the air intake duct and also resists water penetration into the air intake duct. The air intake silencing device is compact in design, easy to install and maintain, efficient in performance, and economical to manufacture.
Accordingly, it is an objective of the instant invention to provide an intake silencer that utilizes a woven fabric material that is effective in reducing the noise generated by the induction passageway of an internal combustion engine.
It is a further objective of the instant invention to provide an intake silencer that utilizes a woven fabric that is effective in reducing intake noise and is also resistant to water penetration.
It is yet another objective of the instant invention to provide an intake silencer for an internal combustion engine that is small in size thereby minimizing engine compartment utilization.
It is a still further objective of the invention to provide an engine intake silencer that is effective, durable, and cost effective to manufacture, install, and maintain.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a portion of the induction passageway including the acoustic membrane.
FIG. 2 is an exploded bottom perspective view of the induction passageway including the acoustic membrane.
FIG. 3 is an exploded top perspective view of the induction passageway including the acoustic membrane.
FIG. 4 is a perspective view of the outlet side of the inlet component of the induction passageway.
FIG. 5 is a side perspective view of the intake duct.
FIG. 6 is a chart describing the physical properties of four examples of material for the woven acoustic membrane.
FIG. 7 is a graphical representation of the airflow resistance test data illustrating the pressure drop as a function of airflow for each of the four examples of woven acoustic material.
FIG. 8 is a graphical representation of test data illustrating the noise transmission loss as a function of frequency for each of the four examples of woven acoustic material.
FIG. 9 is a graphical representation of the water resistance for each of the four examples of woven acoustic material.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter with references to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
FIG. 1 is a perspective view of a portion of the induction passageway including an acoustic membrane. The air inlet silencer assembly includes an inlet component 2 having a longitudinally extending passageway 3 extending between an inlet side 4 and an outlet side 10 . Inlet component 2 is formed by any conventional plastic forming technique. The inlet side 4 of inlet component 2 is configured to operatively engage the vehicle sheet metal. The passageway at the inlet side 4 of inlet component 2 is generally oval; however the oval shape is not necessary; a passageway that is round or rectangular in cross section will suffice without detracting from the invention. The inlet side 4 of inlet component 2 includes an L shaped wall 6 that includes indexing, reinforcement and attachment elements 8 . Elements 8 cooperate with elements located on the vehicle structure. The longer leg of the L shaped wall 6 is formed at an oblique angle with respect to the axis of longitudinally extending passageway 3 . The outlet side 10 of inlet component 2 is also generally oval shaped in this embodiment; however the shape is application specific in a manner as discussed with respect to the inlet. The outlet side 10 is sized and configured connected with an intake duct portion 20 .
FIG. 2 is a bottom perspective view of the air induction passageway with parts shown in an exploded fashion for purposes of clarity. Preferably the acoustic membrane 1 is located on the underside of the intake duct 20 when installed within the vehicle engine compartment. FIG. 3 is a top perspective view of the air induction passageway with parts shown in an exploded fashion for purposes of clarity. As shown in FIGS. 2 and 3 , the air inlet silencer assembly also includes an intake duct 20 . The intake duct 20 includes an inlet 22 that is generally oval in cross section for this embodiment; the actual shape is application specific. The inlet 22 also includes a flange 24 that projects radially outward from the surface walls of the intake duct 20 . Flange 24 operatively engages groove 26 located on the outlet side 10 of inlet component 2 . When the flange 24 is seated within groove 26 , the intake duct 20 and inlet component 2 are mechanically and fluidly connected to one another. The front bell mouth, as shown, includes a soft portion for the forward end of the inlet that is welded to inlet component, or could also be molded as a single piece, and is application specific. The intake duct 20 includes an opening 28 that is generally rectangular in shape formed on its outer surface. Surrounding rectangular opening 28 is a continuous upstanding flange 30 which is formed on the outer surface of intake duct 20 . The flange 30 is directed radially outward from the surface of intake duct 20 . An acoustic membrane 1 is sized to fit within the flange 30 and overlay the rectangular opening 28 . A rectangular grid 32 , having an outer perimeter frame that conforms to the inner rectangular perimeter formed by flange 30 , maintains the woven acoustic membrane 1 in place on the intake duct 20 . The grid 32 also includes a plurality of similarly angled louvers 34 . The acoustic membrane 1 and grid 32 are secured in position on the intake duct 20 with mechanical fasteners, thermally welding, or otherwise molded in place. The rectangular acoustic membrane 1 includes apertures 36 formed adjacent each of the four corners as shown in FIGS. 2 and 3 . Likewise the rectangular grid has a circular recesses 38 formed in each of the four corners of the grid 32 . Apertures 36 and recesses 38 located in each of the corners are in alignment when the acoustic membrane 1 and grid 32 are positioned within flange 30 on intake duct 20 . Acoustic membrane 1 can be attached to grid 32 by suitable fastening means such as plastic insert molding, adhesive, or mechanical fasteners.
FIG. 4 is a perspective view of the outlet side of the inlet component 2 of the induction passageway. As shown in FIG. 4 , air inlet component 2 includes an oval shaped outlet side 10 and groove 26 . Fastening and positioning elements 8 and an L shaped wall 6 are sized and configured to secure the inlet component 2 to the vehicle structure.
FIG. 5 is a side perspective view of the intake duct 20 . As shown in FIG. 5 , intake duct 20 has an oval shaped passageway extending between the inlet and outlet side of intake duct 20 . The inlet side includes a mounting flange 24 configured to mate with groove 26 on inlet component 2 . The upper portion of intake duct 20 includes rectangularly shaped flange 30 . The intake duct 20 is formed by any conventional plastic forming technique. The outlet side of intake duct 20 is fixed and configured for suitable connection to other parts of the intake manifold system, such as an air cleaner housing, a further intake duct, an intake manifold or a throttle body housing with fastening and indexing elements 40 molded into the outer surface.
Acoustic membrane 1 is formed from a woven material such as that made by SaatiTech® under the trademark Saatifil Acoustex™. This material is precisely woven with mono filament fibers to produce uniform mesh openings, thereby creating consistent acoustical resistance. The fibers can be made from polyester, metalester or any other suitable synthetic material. The woven material forming the acoustic membrane 1 within the air intake duct has a pore size than falls within the range of 38 um to 18 um and the thickness falls within the range of 40 um to 125 um. The material of the acoustic membrane 1 is finished with a coating that enables the membrane to repel water.
The acoustic membrane has the physical properties needed to reduce the noise generated within the intake passageway by dissipating pressure waves in the duct. It will also provide the required airflow resistance to allow for the proper balance of air entering the intake passageway through the membrane, and it must also be resistant to the intrusion of water into the intake system. The following tests have been conducted concerning the aforementioned criteria.
FIG. 6 is a chart defining the physical properties of four examples having a different pore size, material thickness and weight used to conduct the previously mentioned tests.
To measure airflow resistance, a test sample of the material was mounted on an airflow tunnel and various levels of airflow from a calibrated source were introduced. The pressure drop across the sample was measured at various flow rates. The graph in FIG. 7 represents the results for each of the four examples whose physical properties as shown in the chart of FIG. 6 .
To measure the loss of noise transmission, a test conduit with a portion of the side wall removed was covered with an acoustic membrane and one end of the conduit was mounted on a speaker box. A four pole transmission loss test was conducted with a pair of microphones mounted on the conduit upstream of the acoustic membrane and the other pair located downstream of the membrane. White noise was introduced into the conduit at the speaker and the noise reduction downstream of the membrane was recorded as a function of frequency. The graph in FIG. 8 represents the noise transmission loss for each of the four examples whose physical properties as shown in the chart of FIG. 6 .
To measure the resistance to water intrusion, a U shaped test conduit was constructed. A portion of the upper wall of the horizontal leg of the U shaped test conduit was removed and covered with a water resistant acoustic material. The U shaped conduit was then submerged in a water tank such that the sample was exposed to a 100 mm column of water for thirty seconds; the upper end of each vertical leg of the U shaped conduits being located above the water line. The quantity of water that passed through the membrane was recorded for each of the four examples whose physical properties as shown in the chart of FIG. 6 and the results shown graphically in FIG. 9 .
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention relates to an air intake duct for an internal combustion engine that is capable of reducing the noise associated with the induction of air. The air intake duct includes an inlet and an outlet as well as an opening in a side wall located between the inlet and outlet. Mounted within this opening is a woven acoustic membrane. The acoustic membrane reduces inlet snorkel noise by dissipating pressure waves in the duct. The woven acoustic membrane is formed from a material that allows sufficient air flow into the air intake duct and also resists water penetration into the air intake duct.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the drilling, completion, and production of an essentially horizontal (hereafter “horizontal”) well section into and along a subsurface, geological formation that contains heavy, viscous hydrocarbons, as disclosed in U.S. Pat. Nos. 5,289,881 and 5,607,018, both issued to Frank J. Schuh.
[0003] 2. Description of the Prior Art
[0004] U.S. Pat. No. 5,289,881 discloses in its FIG. 1 a horizontally extending well bore and casing section which contains steam injection tubing (injection tubing) 32. This injection tubing is terminated at its far down stream end by a choke 22 through which all vaporous steam (steam) injected from the surface of the earth leaves the tubing and enters the well bore casing annulus 42 for injection, through casing perforations 18, into producing zone 14. Zone 14 contains the viscous hydrocarbons that are desired to be produced to and recovered at the earth's surface. U.S. Pat. No. 5,289,881 is hereby incorporated in its entirety by reference.
[0005] U.S. Pat. No. 5,607,018 discloses a related production scheme in its FIG. 9 except that steam leaves the interior of steam injection tubing 132 by way of a series of holes 133 in that tubing. Holes 133 allow steam to exit the tubing in a direction that is directly toward casing 116, i.e., a direction that is essentially perpendicular to the long axes of both the injection tubing and the casing (liner) 116. Put another way, the exiting steam from the injection tubing is pointed directly at the inner surface of the casing, and its perforations 118, for injection of that steam into the hydrocarbon bearing formation 114 to liquefy such hydrocarbons for ultimate production to and recovery at the earth's surface. It is also disclosed in this patent, column 12, that the horizontal portion of the well bore can deviate less than 90° or more than 90° from the essentially horizontal portion of the well bore. U.S. Pat. No. 5,607,018 is hereby incorporated in its entirety by reference.
[0006] For sake of clarity, the horizontal sections of the well bore, casing and injection tubing are all shown in both of the aforesaid patents to be essentially straight along their longitudinal axes. In reality, this is not always the case. In drilling the horizontal portion of a well bore, the driller uses a commercially available instrument known as a three axis accelerometer to direct the drilling of that horizontal section. The typical accuracy for this instrument ranges from ¼ to ½ degree and can cause the driller to unknowingly deviate from the desired path. If the drilling path for any of a number of well known reasons, e.g., subsurface heterogeneities, tends too far upward or downward while drilling in the formation, the driller makes adjustments either up or down to the drilling apparatus to get the drill bit back on the desired drilling path. As explained hereinafter in greater detail, these adjustments, which are made while drilling proceeds unchecked, can result in the horizontal section of the well bore having, at least in parts thereof, a sinusoidal shape along the longitudinal axis of the well bore. Any sinusoidal configuration of the well bore is, upon completion of the well, transferred to the casing and injection tubing contained in the horizontal section of that well bore.
[0007] Thus, in reality, there can be one or more low spots in the horizontal sections of the well bore, casing, and injection tubing which can be substantial. For example, it is not uncommon for a low spot to deviate from about one to about five feet lower in elevation than the adjacent high spot.
[0008] Produced fluids, as used herein, are primarily a combination of liquid water (largely condensed steam) and liquid hydrocarbons that have been mobilized by contact with the steam injected into the formation from the injection tubing by way of the casing perforations. Produced fluids can collect in the aforementioned low spots. Undesired pools of produced fluids in such low spots not only mean lost production of desired hydrocarbons to the earth's surface, but can adversely affect the hydrocarbon production operation, e.g., by impeding or otherwise altering in a deleterious way the flow of steam in the casing annulus that surrounds the injection tubing.
[0009] Accordingly, it is highly desirable to have a horizontal well bore production scheme that overcomes the ill effects of hydrocarbons collecting in casing low spots, and this invention does just that.
SUMMARY OF THE INVENTION
[0010] In accordance with this invention, there is provided a method and apparatus for rendering mobile a viscous hydrocarbon held in a subsurface geologic formation by employing a horizontal well bore completion scheme that includes a steam injection tubing string that contains a plurality of jet nozzles that inject vaporous steam along the injection tubing, and toward a production tubing inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a cross section of a horizontal well completion pursuant to the prior art including an exemplary low spot in the well bore and its associated casing and injection tubing.
[0012] FIG. 2 shows a section of injection tubing employing a jet nozzle pursuant to this invention.
[0013] FIG. 3 shows a larger portion of the injection tubing of FIG. 2 which includes a number of variably positioned and spaced-apart jet nozzles, all within this invention.
[0014] FIG. 4 shows a cross section of a portion of a well completion within this invention including a showing of how the vaporous steam injected by way of a jet nozzle interacts with produced fluids in the casing annulus surrounding the injection tubing.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 shows earth's surface 110 into which has been drilled in a conventional manner an essentially vertical well bore 111 which has been turned essentially 90° from the vertical to form an essentially horizontal well bore section (interval) 112 in hydrocarbon containing formation (reservoir) 114 . At the upstream end of horizontal section 112 of the well bore, a pack off 126 has been installed through which passes 1) steam injection tubing 120 whose horizontal section 132 contains a plurality of apertures (holes) 133 along its longitudinal axis (see FIG. 2 ), and 2) production tubing 124 with its associated production inlet 127 . Production string inlet 127 receives produced fluids from horizontal section 112 , and transmits them by way of production tubing 124 to earth's surface 110 for recovery and other processing as desired.
[0016] Steam injected from earth's surface 110 through injection tubing 120 leaves the interior of that tubing by way of both holes 133 , as shown by arrows 130 , and choke 122 ; and enters the annulus 135 inside casing 116 , which annulus surrounds horizontal section 132 of injection tubing 120 . Annulus 135 has a substantially larger internal volume than the internal volume of injection tubing 120 , e.g., a volumetric ratio of annular volume to injection tubing volume of from about 3/1 to about 5/1. This steam then leaves the interior of casing 116 by way of certain of the apertures 118 that extend around the circumference of section 112 of casing 116 , and enters the interior of formation 114 , as shown by arrows 136 . This forms a steam cavity in formation 114 from which some hydrocarbon has been recovered and in which fresh steam is motivating (liquefying) additional viscous hydrocarbon present in the walls of such steam cavity. Produced fluids enter annulus 135 by way of certain other apertures 118 as shown by arrows 138 .
[0017] Line 140 in FIG. 1 denotes the interface between vaporous steam from holes 133 and liquid, produced fluids from certain apertures 118 as afore said, and further shows that a certain volume of produced fluids will be trapped in low spot 141 of this FIG. 1 . Low spot 141 can contain a substantial volume of trapped produced fluids because it can extend for tens of feet in length and be from one to five feet lower in elevation 150 than its associated high spot 151 . Holes 133 inject steam directly toward the interior surface 152 and holes 118 of casing 116 , i.e., essentially perpendicular to the longitudinal axis of injection tubing 120 , and are not effective in cleaning out produced fluids trapped in low area 141 of annulus 135 for recovery of same at the earth's surface. In a given well, horizontal section 112 can contain a plurality of such low spots, just one such spot 141 being shown in FIG. 1 for sake of brevity and clarity.
[0018] FIG. 2 shows a section of injection tubing 120 that employs a jet nozzle pursuant to this invention. Tubing 120 has an outer surface 201 and an inner surface 202 . The longitudinal axis of tubing 120 is shown at 200 . Steam from the earth's surface passes through interior 203 of tubing 120 in the direction shown by arrow 204 . Steam 204 can be at a pressure of from about 250 to about 680 psia, and a temperature of from about 400 to about 500° F. Jet nozzle 205 is in fluid communication between injection tubing interior 203 and casing annulus 135 . Outer surface 201 carries a jet nozzle 205 which contains a constriction 206 which accelerates the velocity of steam 204 , and a narrower passage (choke) 207 which further accelerates the compressed, pressurized steam 208 into lower pressure, larger volume annulus 135 , thus injecting steam 208 with substantial force into annulus 135 . Such compressed steam 208 is also deliberately injected along the long axis 200 , i.e., outer surface 201 , of injection tubing 120 in a direction towards production inlet 127 ( FIG. 1 ) to move both the produced fluids and steam toward the inlet for production to the earth's surface. This injection of compressed steam 208 into annulus 135 not only forcibly moves produced fluids towards production inlet 127 , but at the same time removes essentially all trapped production fluids held in one or more low spots, e.g., area 141 of FIG. 1 , that can occur from location to location along the length of injection tubing 120 . Choke 207 can be, but is not necessarily, essentially round, and has a diameter of from about 7/32 to about 14/32 of an inch, or the equivalent if not round.
[0019] FIG. 3 shows a longer section of injection tubing 120 containing a plurality of jet nozzles 205 . Note that downstream end 300 is closed and does not contain a choke 122 . Thus, choke 122 has been eliminated with out eliminating the function thereof. The injection of compressed steam 208 into annulus 135 is so robust that nozzles 205 can be spaced about the outer surface (periphery) 201 of tubing 120 in a random or patterned fashion and the results of this invention still realized. Thus, as shown in this Figure, nozzles 205 can be distributed on the top, bottom, and/or sides of tubing 120 as desired, or any individual choice or combination thereof.
[0020] By using a plurality of nozzles 205 that discharge steam essentially parallel to the long axis 200 of injection tubing 120 , and toward the production inlet 127 , sufficient flow-energy is generated to transport essentially all produced fluids, including any and all produced fluids trapped in low spots, to production inlet 127 .
[0021] The amount of flow-energy generated, and the lift capacity of the nozzle array employed will vary considerably depending on the details of the particular well completion, and can be controlled by the steam injection rate at the earth's surface, the production rate of produced fluids at the earth's surface, and nozzle sizing, spacing, and positioning along the injection tubing, all of which can readily be determined by one skilled in the art once apprised of this invention. With close spaced nozzles, the available energy is greater than required to transport produced fluids, and the uniformity of steam distribution maximized. With widely spaced nozzles, the available energy exceeds the transport requirement. Although nozzle spacing can vary widely, from a practical point of view a maximum spacing could be about 400 feet, and a minimum spacing about 35 feet. The spacing is from about 100 to about 150 feet under most conditions. Injection tubing 120 can, if desired, be essentially centralized inside annulus 135 to provide a clearer path for steam flow around the entire circumference of the injection tubing. Desirably, nozzles 205 will be located near the center of annulus 135 between the outer surface 201 of the injection tubing and the inner surface 400 (see FIG. 4 ) of casing 116 . Also desirably, the operation is carried out at an essentially constant temperature and pressure within the steam cavity formed by mobilizing hydrocarbons in formation 114 . Minimizing any excess of flow-energy can be obtained by maintaining an essentially constant pressure, which also favors close spaced nozzles.
[0022] The maximum lift capacity can occur at the bottom of the horizontal portion of the well bore adjacent the closed end 300 ( FIG. 3 ) of injection tubing 120 . At that location, a 280 foot spacing of nozzles can provide an average of about 3 feet of lift per hundred foot of horizontal bore hole. This lift rate can vary from about 1.2 to about 4.8 per hundred feet over the life of the well. In the middle of the horizontal interval the lift capacity is less than half of the maximum, while the lift rate for the first nozzle below packer 126 is about 30% of the maximum. Selecting a spacing that provides the required lift for the upward undulations in the horizontal interval of the well bore can lessen the variation of pressure along the horizontal borehole.
[0023] The produced fluids rate at the earth's surface increases rapidly as the steam cavity expands upward to the top of formation 114 . From that point it declines until the economic production rate limit is reached. The rate of liquid steam condensate production at the earth's surface is essentially the same as the steam injection rate at the earth's surface. Thus, for a typical design the steam injection rate at the earth's surface can start at about 12,000 pounds per hour, reach a peak of about 21,000 pounds per hour, and drop to about 11,000 pounds per hour as the economic production limit is reached.
[0024] FIG. 4 shows a cross-section of how produced fluids flow in the operation of this invention between adjacent jet nozzles 205 and 405 , with nozzle 405 being located on the side of injection tubing 120 , rotated about 90° from nozzle 205 . Nozzle 205 is designed to introduce the steam vapor at the rate that will enter the steam cavity between nozzles 205 and 405 . Line 406 shows the interface between essentially only vaporous steam, and essentially liquid produced fluids. Thus, immediately adjacent the outlet of nozzle 205 is primarily steam with a minor amount of liquid at the bottom of annulus 135 . Intermediate nozzles 205 and 405 , as steam escapes into formation 114 by way of holes 118 (arrows 136 ), the share (fraction) of liquid in annulus 135 increases. Just up stream of nozzle 405 the last of the steam vapor exits the annulus at that location. Thus it can be seen that steam 208 is a substantial propellant of liquid (produced fluids) that enters the annulus by way of holes 118 at the bottom of casing 116 as shown by arrow 138 . Note that the produced fluids are also forcibly propelled in the direction of arrows 208 which is essentially parallel to long axis 200 ( FIG. 3 ) and toward production inlet 127 ( FIG. 1 ).
[0025] FIG. 5 shows a cross section 5 - 5 of FIG. 4 , and further shows that annulus 135 is essentially 90% full of produced fluids at this location.
[0026] FIG. 6 shows a cross section 6 - 6 of FIG. 4 , and further shows that annulus 135 is about 40% full of produced fluids at this location.
[0027] FIG. 7 shows a cross section 7 - 7 of FIG. 4 , and further shows that annulus 135 is about 80% full of produced fluids at this location.
[0028] Thus, it can be seen that produced fluids are driven by steam 208 toward inlet 127 , and, because of the flow-energy imparted by a plurality of spaced apart jet nozzles along the length of injection tubing 120 , not only moves newly entering produced fluid, but, at the same time, moves trapped produced fluids from low spots such as area 141 ( FIG. 1 ).
EXAMPLE
[0029] Formation 114 is at a depth of about 100 feet, and a thickness of about 36 feet. A well bore is drilled down to the formation and then horizontally in that formation for about 1,300 feet about 1 foot above the bottom of the formation. The well is cased with 9⅝ inch casing from the earth's surface to the beginning of the horizontal interval. The horizontal interval is cased with pre-perforated 7 inch outer diameter liner 116 (6.366 inch inner diameter). The 3½ inch outer diameter (2.992 inch inner diameter) production tubing string 124 extends from the earth's surface to and just through the dual packer 126 , terminating at production inlet 127 . Four inch outer diameter (3.548 inch inner diameter) steam injection tubing 120 extends essentially to the bottom of the well bore, i.e., far end of the horizontal section of the well bore and its casing ( FIG. 1 ). Thirteen horizontally oriented (with respect to the long axes of both the casing and injection tubing) steam injection nozzles 205 , 405 , etc. are placed at about 100 foot intervals along and around ( FIG. 3 ) the length of the injection tubing with their outlets facing toward inlet 127 .
[0030] The horizontal section of the well bore and the steam cavity in formation 114 are kept at an essentially constant temperature and pressure of about 350° F. and about 135 psia.
[0031] The 13 nozzles use an initial steam injection rate of about 945 pounds per hour per nozzle, using nozzle chokes from about 0.302 to about 0.308 inches. Individual nozzle steam emission velocities are about 1,339 feet per second. The horizontal interval varies in a sinusoidal manner up and down from the intended well bore path about 1 foot.
[0032] After 3.5 years of production, the maximum steam injection rate is about 20.6 million BTU's per hour, thereby producing about 200 barrels of hydrocarbon per day and about 1,520 barrels of water per day. At this time each nozzle is emitting about 1,620 pounds of steam per hour at an exit velocity of about 1,384 feet per second.
[0033] At the multi-year producing life of the well, the injection rate is 11.1 million BTU's per hour of steam. The final producing rate is about 71 barrels of hydrocarbon per day and about 820 barrels of water per day. The final individual nozzle flow rate is about 865 pounds per hour with a steam emission velocity of about 1,334 feet per second.
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A method and apparatus for recovering viscous hydrocarbons from a subsurface reservoir holding the same using an essentially horizontal well bore having a production inlet and containing steam injection tubing that carries a plurality of jet nozzles oriented to emit steam along said injection tubing towards said production inlet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to a densitometer and, more particularly, to a densitometer for use in a photodosimeter system having a high degree of accuracy over a wide range of measurements.
2. Description of the Prior Art.
In my copending application Ser. No. 491,875, filed concurrently herewith, for Photodosimeter Film Badge, there is disclosed a photodosimeter film badge sensitive to non-ionizing radiation which is useful during phototherapy for the treatment of hyperbilirubinemia in the newborn. Such film badge is capable of permitting the measurement of the total irradiance effective in decomposing bilirubin. The film badge undergoes an optical density change as a result or irradiation by the phototherapy lamps and such density change is directly proportional to the time interval of the irradiance. The optical density change occurs very slowly so that the film badge is responsive to phototherapy irradiance over periods extending from a few hours to as many as 96 hours.
Since the optical density of the film changes irreversibly as a function of irradiance, such optical density may be measured directly without any chemical processing of the film. This permits exposure to be monitored continuously. However, in order to derive the full benefits of the film badge of my copending application, it is necessary to be able to measure density extremely accurately, over a wide range of densities.
More specifically, phototherapy for the treatment of hyperbilirubinemia in a newborn typically continues for a minimum of a few hours and a maximum of four days (96 hours). With an irradiance level of approximately 1 mW/cm 2 , there is a total exposure, over a period of 100 hours, of approximately 360 joules. Any system used for measuring exposure must measure to an accuracy of about 15 minutes in an exposure interval of 100 hours, requiring an accuracy of about 0.25 percent, or about 1 part in 400. Since the film badge of my copending application exhibits a total density change of about 3.000 in a 100 hour interval, such an accuracy implies that a density change of 0.008 must be accurately measured. Thus, any densitometer must be extremely accurate, the output reproducible, and it must operate over a wide range of densities. However, while many commercial densitometers are available at prices ranging from several hundred to several thousand dollars, no reasonably priced densitometer meets these requirements.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a densitometer for use in a photodosimeter system meeting all of the requirements specified above. The present densitometer is capable of providing an accuracy of 1 part in 4,000 or 0.001 density units over a density range of 4.000. The output of the present densitometer is reproducible and it operates over a wide range of densities. The present densitometer incorporates an automatic mechanism which insures that at a density of zero, the displayed output is also zero.
Briefly, the present densitometer for providing an output which is a function of the density of a film badge or other optical element comprises: a source of light; means for holding the film badge in the path of the light, the film badge transmitting an amount of light which is inversely proportional to the density thereof; a photodiode positioned to receive the light transmitted through the film badge for generating a current signal which is directly proportional to the intensity of the received light, the current signal having a non-zero value when no light is received by the photodiode; means responsive to the photodiode for converting the current signal to a voltage signal which is directly proportional to the intensity of the received light; means for biasing the current-to-voltage converting means so that the voltage signal is zero when no light is received by the photodiode; means for generating a reference voltage; circuit means responsive to the voltage signal and the reference voltage for generating an output signal proportional to the log of the ratio of the reference voltage to the voltage signal, the output signal being proportional to the density of the film badge; means for displaying the output signal; means for adjusting the reference voltage until the output signal is zero; and means for sensing the presence of the film badge in the holding means for disabling the adjusting means when the film badge is present.
OBJECTS
It is therefore an object of the present invention to provide a densitometer.
It is a further object of the present invention to provide a densitometer for use in a photodosimeter system having an accuracy of at least 1 part in 400.
It is a still further object of the present invention to provide a densitometer having a reproducible output capable of accurately measuring density over a wide range of densities.
Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiment constructed in accordance therewith, taken in conjunction with the accompanying drawings wherein like numerals designate like parts in the several figures and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic view of the optical geometry of the present densitometer;
FIG. 2 is a block diagram of a densitometer constructed in accordance with the teachings of the present invention; and
FIG. 3 is a block diagram of a possible modification to the densitometer of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The film badge disclosed in my beforementioned copending patent application is responsive to the irradiance effective in decomposing serum bilirubin. The film badge disclosed therein initially has a density of between 3 and 4, thereby initially transmitting only a small amount of the light incident thereon. As the film badge continues to be exposed by the illumination used during phototherapy for the treatment of hyperbilirubinemia, the density decreases at a wavelength of approximately 455 nanometers. This decrease in density is directly proportional to exposure and must be measured to provide a useful output.
The present densitometer, generally designated 10, is designed to provide an output which is a function of the density of a film badge, generally designated 11, or any other optical element, in a very narrow wavelength interval in the vicinity of 455 nm. Thus, and with reference to FIG. 1, densitometer 10 includes a lamp 12 which is typically a high efficiency tungsten lamp with a built-in parabolic reflector, since such a lamp provides a light output in the frequency spectrum of interest. The output of lamp 12 passes through a first filter 13 which passes blue light and blocks visible and infared light. Filter 13 is typically a blue glass filter. The light passing through filter 13 is collimated by a lens 14 and conducted to a film holder 15 capable of holding film badge 11 perpendicular to the collimated rays. This technique is used so as to illuminate the entire area of film badge 11, which increases the accuracy of densitometer 10 when the density of film badge 11 is high and only a small amount of light passes therethrough.
The light transmitted through film badge 11, which is inversely proportional to the density thereof, is focused by a second lens 16 onto a detector 17. Interposed between lens 16 and detector 17 is a second blue glass filter 18 designed to block stray light. Interposed between filter 18 and detector 17 is a bandpass filter 19 having a very narrow passband, on the order of 5 - 10 nm, in the vicinity of 455 nm. Detector 17 generates a signal on a line 20 which is directly proportional to the intensity of the received light. Thus, this signal is inversely proportional to the density of film badge 11 in the vicinity of 455 nm.
Referring now to FIG. 2, detector 17 may be any wellknown light responsive device for generating a signal proportional to the light incident thereon. On the other hand, it should be recognized that since the initial density of film badge 11 is quite high, the amount of light transmitted to detector 17 will be quite low and the output of detector 17 will also be quite small. Therefore, it is important that the output signal from detector 17, when no light is received thereby, be quite small since fluctuations therein as a result of noise will effect the accuracy of densitometer 10. With this in mind, detector 17 is preferably a vacuum photodiode, such as RCA Model 1P42. Such a photodiode acts as a current source which generates a current signal which is directly proportional to the intensity of the received light.
Densitometer 10 also includes a bias voltage source 21 which applies a suitable bias voltage to the photodiode in detector 17. By properly selecting the value of the bias voltage, the current from detector 17 when no light is received thereby may be minimized. When an RCA 1P42 vacuum photodiode is used, the value of bias voltage source 21 is preferably 15 volts.
The output of detector 17, on line 20, is applied to a current-to-voltage converter 23 which converts the current signal from detector 17, on line 20, to a voltage signal, on line 24. Furthermore, current-to-voltage converter 23 operates such that the voltage signal on line 24 is zero when no light is received by detector 17. More specifically, current-to-voltage converter 23 preferably includes a conventional operational amplifier 25 having a conventional feedback resistor 26 and also a feedback capacitor 27 for integration to eliminate noise. The output of detector 17, on line 20, is applied to one input of operational amplifier 25 whereas the other input, which is normally grounded, receives, over a line 28, the output of a bias voltage source 29. The bias voltage provided by source 29 is adjusted so that the output of operational amplifier 25, on line 24, is zero when no light is received by detector 17. This may be achieved, very simply, by covering detector 17 so that no light is received thereby and by adjusting bias voltage source 29 until the output of operational amplifier 25 reaches zero.
The output of converter 23 is now a voltage signal which is zero when no light is received by detector 17 and which increases as the intensity of the light incident on detector 17 increases. Thus, the voltage signal on line 24 is directly proportional to the transmittance of film badge 11. However, since exposure, the desired quantity, is a function of density, rather than transmittance, the output of converter 23 is applied to the signal input (S) of a log-ratio circuit 30. That is, density (D) = -log T, where T = transmittance, and circuit 30 performs this mathematical operation. More specifically, since T = (S/R), D = -log (S/R) or log (R/S). Log-ratio circuit 30 receives, at its reference input (R), a signal over a line 31 from a reference voltage generator 32. Log-ratio circuit 30 is a conventional circuit for generating an output signal, on a line 33, which is proportional to the log of the ratio of the reference input to the signal input.
As will be explained more fully hereinafter, the value of the reference voltage from generator 32 may be adjusted to provide a zero output signal when the density of film badge 11 is zero. Thereafter, as the density of film badge 11 increases, the output of log-ratio circuit 30, on line 33, will increase proportionately.
Initial zero adjustment of the output of log-ratio circuit 30 may be achieved simply by removing film badge 11 from holder 15 so that the light incident on detector 17 is indicative of a density of zero. At this time, the output of reference voltage generator 32 may be adjusted to yield a zero output from circuit 30. Full-scale calibration of circuit 30 is achieved by blocking all light to detector 17 so that the output of converter 23, on line 24, is zero. The internal elements of log-ratio circuit 30 may then be adjusted to provide the desired output. Thereafter, as the density of film badge 11 varies between its minimum and maximum values, the output of log-ratio circuit 30, on line 33, will vary proportionately.
In order to display density to the desired degree of accuracy, the output of log-ratio circuit 30, on line 33, is applied to a twelve-bit analog-to-digital converter 35 which generates a digital output, on a line 36, having an accuracy of 1 part in 4,000, representing 0.001 density units over a density range of 4.000. This output is applied to a digital display device 37 capable of displaying four digits.
It is obvious that densitometer 10 will continue to provide an accuracy of 1 part in 4,000 only as long as the circuit elements do not vary in value by a greater amount. However, in practice, this will not occur and display 37 cannot continue to generate an output of 0.000 for any length of time with film badge 11 removed from holder 15. Therefore, according to the preferred embodiment of the present invention, the output of analog-to-digital converter 35 is applied to a feedback circuit, generally designated 40, the output of which is applied over a line 41 to reference voltage generator 32 to adjust the value of the voltage output thereof until the signal output from converter 35 is zero. More specifically, feedback circuit 40 would be a conventional logic circuit for sensing when the output of converter 35 is different from zero and whether such difference is positive or negative. Circuit 40 would then apply a suitable signal over line 41 to signal generator 32 to cause generator 32 to make an appropriate adjustment in its output voltage to reduce such difference to zero. This check of the output of converter 35 would be repeated regularly and if the zero level changes, an increased or decreased potential is applied to the reference input of circuit 30 to drive the output of converter 35 back to zero. Thus, any variations in circuit values with time will be automatically cancelled.
Obviously, circuit 40 operates only when film badge 11 is removed from holder 15 since only at that time is the output of converter 35 zero. Therefore, to disable circuit 40 when a film badge 11 is inserted into holder 15, dosimeter 10 includes a circuit 42, which is mechanically connected to holder 15, as shown at 43, for sensing when film badge 11 is inserted into holder 15. When film badge 11 is inserted, sensor 42 generates a signal on a line 44 which is applied to zero sensor 40 to disable same.
It will be apparent to those skilled in the art that the output of log-ratio circuit 30 will be zero only when the output of reference voltage generator 32 is equal to the output of converter 23, thereby equalizing the values of the inputs to circuit 30. Therefore, the output of converter 23 itself may be used to provide a reference voltage when film badge 11 is removed from holder 15. More specifically, and with reference now to FIG. 3, the output of current-to-voltage converter 23, on line 24, may be applied not only to the signal input of log-ratio circuit 30 but also to the input of a sample and hold circuit 50, the output of which is applied, over a line 51, to the reference input of circuit 30. This permits the complete elimination of reference voltage generator 32 and feedback circuit 40. However, under these circumstances, the output of film presence sensor 42, on line 44, is applied to sample and hold circuit 50.
In operation, when film badge 11 is removed from holder 15, as sensed by circuit 42, circuit 50 operates to sample and hold the output of converter 23 and to apply such output to the reference input of circuit 30. Thus, circuit 50 generates a reference signal on line 51 which is automatically equal to the signal input to circuit 30 by virtue of the fact that it is, in fact, the same signal. Therefore, with film badge 11 removed from holder 15, the output of circuit 30 remains zero in spite of fluctuations in the voltage on line 24.
On the other hand, the hold capability of circuit 50 is required when an actual density measurement is being made. That is, when film badge 11 is inserted into holder 15, the signal on line 44 from film presence sensor 42 causes circuit 50 to open the connection between lines 24 and 51 and, thereafter, to apply the held voltage value to line 51. This held voltage thereby acts as the reference voltage. In addition, as soon as film badge 11 is removed from holder 15, such held voltage value is adjusted, as necessary, with fluctuations over line 24.
While the invention has been described with respect to a preferred physical embodiment constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims.
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A densitometer for providing an output which is a function of the density of a film badge in a photodosimeter system. The light passing through the film badge is received by a photodiode which generates a current signal which is directly proportional to the intensity of the received light. The current signal is converted to a voltage signal, the converting means being biased so that the voltage signal is zero when no light is received by the photodiode. The voltage signal is applied, together with a reference voltage, to a log-ratio circuit which generates an output signal proportional to the log of the ratio of the reference voltage to the voltage signal, the output of the log-ratio circuit being displayed. A circuit is operative, when the film badge is removed from the light path, to adjust the reference voltage until the output of the log-ratio circuit is zero.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a device for grinding tablets/pills. More particularly, although not exclusively, the invention relates to a handheld device into which whole tablets can be inserted for grinding into particulate form.
[0002] Tablets come in different sizes depending upon the prescribed or desired dosage. Some tablets are provided with a score line to facilitate easy breakage into two parts. Where a dosage smaller than half a tablet is desired, further breakage becomes difficult—especially for elderly people or people with arthritic conditions for example. For this reason, it is often desired to grind tablets into powdered form for subsequent ease of portioning.
[0003] Some tablets are not rapidly absorbed into the body after being taken. Grinding of tablets into granular or powdered form increases the rate of absorption in the body.
OBJECTS OF THE INVENTION
[0004] It is an object of the present invention to provide a handheld device with which consumers can grind tablets into smaller particles.
DISCLOSURE OF THE INVENTION
[0005] There is disclosed herein a device for grinding tablets, comprising:
a body, an electric motor housed within the body, a power source connected to the electric motor via a switch, a grinder driven to rotate by the electric motor, a tablet chute to the grinder, and a particle bin attached to or formed integrally with the body for receiving particles from the grinder.
[0012] Preferably, the grinder is substantially cylindrical and rotates about a longitudinal axis thereof.
[0013] Preferably, the device further comprises a substantially cylindrical grinding cavity within which the grinder rotates.
[0014] Preferably, the tablet chute extends radially of the longitudinal axis of the grinder.
[0015] Preferably, the tablet chute extends tangentially of the grinding cavity.
[0016] Preferably, the grinder includes a pair of diametrically opposed, longitudinally extending blades.
[0017] Alternatively, the grinder includes four longitudinally extending blades in respective diametrically opposed pairs.
[0018] As a further alternative, the grinder can include a peripheral helical blade.
[0019] AS yet a further alternative the grinder can comprise an abrasive grinding surface.
[0020] Preferably, the grinding cavity includes an exit port communicating with the particle bin.
[0021] Preferably, the particle bin comprises a sliding drawer.
[0022] Preferably, the device further comprises a door covering the tablet chute.
[0023] Preferably, the device further comprises a gearbox for transmitting torque of the motor to the grinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
[0025] FIG. 1 is a schematic perspective illustration of a tablet grinding device,
[0026] FIG. 2 is a schematic cross-sectional side elevation of the device of FIG. 1 ,
[0027] FIG. 3 is a schematic cross-sectional end elevation of the device of FIGS. 1 and 2 having a first tablet chute configuration,
[0028] FIG. 4 is a schematic cross-sectional end elevation of a tablet grinding device having an alternative tablet chute configuration,
[0029] FIG. 5 is a schematic depiction of a twin blade cylindrical grinder,
[0030] FIG. 6 is a schematic depiction of a four blade cylindrical grinder,
[0031] FIG. 7 is a schematic depiction of a helical blade cylindrical grinder, and
[0032] FIG. 8 is a schematic depiction of a cylindrical grinder having an abrasive grinding surface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] In the accompanying drawings there is depicted schematically a tablet grinding device G. The grinding device comprises a pair of body halves 4 and 7 typically of moulded ABS plastics material and connected together to form a casing to which a footplate 23 is affixed. A number of rubber finger grips 2 and 3 are provided at the casing exterior.
[0034] Internally of the casing above the footplate 23 , there is a battery compartment which houses a pair of batteries 22 . An access door 5 encloses the battery compartment.
[0035] The batteries bear against a set of contact plates 21 and 24 from which wires extend to a switch 9 at the top of the casing. The switch 9 is in contact with a switch knob 1 that is exposed at the top of the casing.
[0036] Electrical wire 25 extends from the switch 9 to a DC electric motor 26 situated within the casing above the battery compartment.
[0037] A gearbox including casing parts 10 and 18 houses a number of reduction gears 11 , 12 , 13 , 14 , 16 , 17 and 19 and shafts 15 and 17 . The output shaft of motor 26 is input to the gearbox and the final gear 12 of the gearbox is mounted upon a grinder shaft 28 upon which a cylindrical grinder 29 is fixed so as to rotate therewith.
[0038] The grinder 29 is located within a cylindrical grinding cavity 27 . The grinder 29 is typically made of steel and in one embodiment ( FIG. 5 ) includes a pair of diametrically opposed, longitudinally extending straight blades 32 . In another embodiment ( FIG. 6 ), the cylindrical grinder 29 ′ comprises four longitudinally extending straight blades 32 ′ in respective diametrically opposed pairs separated by 90°. In a third embodiment ( FIG. 7 ) the cylindrical grinder 29 ″ includes a single helical blade 32 ″, extending from one end of the grinder's cylindrical surface to the other. In another embodiment (not shown) two or more helical blades might be provided either extending in the same direction or crossing one another in opposite directions. In a fourth embodiment ( FIG. 8 ), the outer surface of the cylindrical grinder 29 ′″ has an abrasive surface 33 somewhat like the surface of sandpaper against which the tablets wear.
[0039] A tablet entry chute 30 extends from the top of the casing beneath a tablet chute door 8 to the cylindrical grinding cavity 27 . In the embodiment depicted in FIG. 3 , the entry chute 30 of tablet grinder G 1 extends substantially tangentially from the grinding cavity 27 , whereas in the embodiment G 2 of FIG. 4 , the grinding chute 30 extends radially of the grinder shaft 28 .
[0040] The cylindrical grinding cavity 27 has an exit passage 31 communicating with a particle bin 6 . The particle bin 6 attaches to the casing like a drawer which can be opened by sliding to reveal ground tablet particles, or removed completely for inversion to dispense ground particles therefrom.
[0041] In use, whole tablets are inserted into the tablet chute 30 after having opened the tablet chute cover 8 . Either before inserting the tablets into the chute or thereafter, the user slides the switch knob 1 to activate the motor, which in turn drives the gearbox to rotate the cylindrical grinder 29 . The blades 32 , 32 ′, or 32 ″, disintegrate the tablet to form particulate material which falls downwardly via exit passage 31 to the particle bin 6 . Once no further grinding sound is heard by the user, the switch knob 1 can be returned to its OFF position.
[0042] The switch knob 1 might have three positions. For example, it could have a central OFF position and FORWARD and REVERSE positions at either side of the OFF position enabling the user to reverse rotate the grinder 29 if necessary. To this end, the switch 9 can be connected electrically to motor 26 to energise it in either polarity.
[0043] It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, the device might be provided with a tablet magazine for containing a plurality of tablets for individual delivery to the grinding cavity.
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A device for grinding tablets includes a body, an electric motor housed within the body, a power source connected to the electric motor via a switch, a grinder driven to rotate by the electric motor, a tablet chute to the grinder, and a particle bin attached to or formed integrally with the body for receiving particles from the grinder.
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BACKGROUND OF THE INVENTION
[0001] At least one embodiment of the present invention generally relates to variable speed power tools. More particularly at least one embodiment of the present invention relates to controlling the speed and frequency of electric motors in power tools.
[0002] Hand held power tools, such as electric drills screw drivers and the like, use electric motors to power a chuck holding a tool. Such power tools usually include a trigger which is manually operated by a user with the motor being controlled by the user pressing the trigger. Power tools in which the motor and chuck speed are varied based on the amount that the trigger is depressed are known as variable speed power tools. Power tools include motors that are powered by an AC or DC power source that delivers current to the motor. As the user squeezes the trigger, more power is delivered to the motor to cause the shaft to rotate faster. Once the trigger is released, current is no longer delivered to the motor.
[0003] Typically, power tools include speed control circuits that use pulse width modulation (PWM) to control the voltage applied to the motor. More specifically, the PWM control circuit rapidly cycles power on and off to the motor. The PWM control circuit controls the duty cycles based on the trigger position. The more the trigger is squeezed the larger the on-time duty cycle is and the faster the shaft rotates.
[0004] Power tools often experience high current or stalled conditions when a work load exceeds the capability of the motor or the battery. These conditions create extreme loads on the battery, motor and other electric components of the tool. These conditions also reduce the effectiveness of the tool by damaging the battery, motor and other electric components of the tool.
[0005] Conventional power tools exaggerate the negative effects of stalled conditions by including a by-pass contact that, when closed, by-passes the variable speed control. The by-pass contact is closed when the desired power output exceeds a certain point. When the by-pass contact closes, the tool directly connects the motor and battery to deliver all available power to the motor. Under certain conditions the use of a by-pass contact is undesirable because it may damage the battery, motor or other electrical components in the tool. The use of a by-pass contact therefore may lead to a reduced tool life and may also lead to a stalled motor condition.
[0006] A need exists for a control circuit that more effectively monitors the electrical condition of the power tool in determining the duty cycle. A need also exists for a control circuit that monitors the electrical conditions of the power tool in determining the frequency of the duty cycle. A need further exists for a power tool controller that provides a maximum amount of power to the motor without damaging the battery and that eliminates or reduces stalled motor conditions.
BRIEF SUMMARY OF THE INVENTION
[0007] In accordance with at least one embodiment of the present invention, a control system is provided for driving a power tool, comprising a power source, a motor adapted to drive a shaft, and a power switching unit interconnecting the power source and the motor. The power switching unit applies a pulse width modulated (PWM) drive signal from the power source to the motor. A controller monitors at least one electrical characteristic of at least one of the power source, motor and power switching unit, and adjusts an operating duty cycle of the PWM drive signal based on the electrical characteristic.
[0008] One aspect of another embodiment of the present invention is monitoring the voltage of the power source, the motor or the power switching unit. Optionally, the system may monitor the current of the power source, the motor or the power switching unit.
[0009] Another aspect of an embodiment of the present invention is the use of a controller that detects a voltage drop across the power source. Optionally, the controller detects a voltage drop across said power source and the motor.
[0010] In one embodiment of the present invention, the power switching unit comprises a power MOSFET connected in series between the power source and the motor. The power MOSFET switches between ON and OFF states to vary the pulse width of said PWM drive signal. Optionally, an input lead connected to the controller provides a user trigger signal indicative of a trigger position or a motor speed. Alternatively, the PWM drive signal adjusting the motor speed.
[0011] Another aspect of an embodiment of the present invention is the use of a voltage sensor to monitor a voltage drop across at least one of the power source, the motor and the controller. Optionally, the controller determines a target duty cycle representative of a target motor condition selected by a user and sets the operating duty cycle below the target duty cycle or at a value not equal to the target duty cycle. Optionally, the target motor condition may constitute the motor speed or torque. Alternatively, the operating duty cycle may be set from the peak current and time period over which the power source delivers a current at or near the peak current.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, embodiments which are present preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentality shown in the attached drawings.
[0013] [0013]FIG. 1 illustrates a power tool formed according to one embodiment of the present invention.
[0014] [0014]FIG. 2 illustrates a schematic diagram of a control circuit according to one embodiment of the present invention.
[0015] [0015]FIG. 3 is a graph of applied voltage versus time for different power tools and preferred embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] [0016]FIG. 1 illustrates an electric power tool 10 with a body 70 , a trigger 80 , a forward/reverse control 90 , a variable speed motor 20 , a chuck 30 for holding a tool, a DC battery 40 , a drive shaft 60 and a control system 50 for driving the motor 20 . The motor 20 of the tool 10 is adapted to drive the chuck 30 through the shaft 60 . The trigger 80 allows the user to vary the speed of the chuck 30 by controlling the current delivered from the battery 40 to the motor 20 based on how much the user squeezes the trigger 80 .
[0017] [0017]FIG. 2 illustrates the control system 50 formed in accordance with one embodiment of the present invention. The control system 50 is connected in series with DC battery 40 and motor 20 . The DC battery 40 has a positive terminal 41 and a negative terminal 42 electronically connected to the first set of contacts 100 . The terminals 41 and 42 of the battery 40 are connected to a first set of contacts 100 and arranged in a series with an on-off switch 110 . A brake switch 115 and a power MOSFET 130 are arranged in series with one another and are connected across the contacts 100 and the battery 40 .
[0018] A voltage regulator 140 include an input connected through one contact 100 to one terminal of the battery 40 . An output of the voltage regulator 140 is connected to a power input terminal VCC on a microprocessor 120 . The voltage regulator 140 regulates the voltage delivered to the microprocessor 120 . The voltage regulator 140 also includes a ground terminal GND that is connected to one end of a potentiometer 150 . An opposite end of the potentiometer 150 is connected to the input terminal VCC of the microprocessor 120 . A center tap on the potentiometer 150 is connected to a reference input terminal GP 4 on the microprocessor 120 to monitor the output voltage of the voltage regulator 140 . The microprocessor 120 is connected to an audio output 160 .
[0019] A first voltage divider 170 , 171 is provided between the terminals of the battery 40 . A center tap 172 of the voltage divider 170 , 171 is connected to an input terminal GP1 of the microprocessor 120 to monitor the voltage potential across the battery 40 . A second voltage divider 180 , 181 is provided across the terminals of the power MOSFET 130 . A center tap 182 of the voltage divider 180 , 181 is connected to an input terminal GP2 of the microprocessor 120 to monitor the voltage potential across the power MOSFET 130 . Optionally, an AC power source may be used with an AC to DC converter to deliver a DC power to the first set of contacts.
[0020] The control system 50 determines the duty cycle and/or frequency of the motor 20 when the user squeezes the trigger 80 . The on-off switch 110 is controlled by the trigger 80 and is opened when the trigger 80 is released and closed when the trigger 80 is squeezed. Optionally, the on-off switch 110 may also be opened and closed based on a button located proximate the trigger 80 to afford added sofets. The DC battery 40 is attached to, and disconnected from the motor 20 by the on-off switch 110 . The inductance and resistance of the motor 20 are schematically modeled in FIG. 2 as coil inductance 21 and coil resistance 22 . The motor 20 also includes a forward/reverse switch 25 that allows the user to switch the direction of the tool through a forward reverse control 90 . When the user completely releases the trigger 80 the on-off switch 110 is opened and the brake switch 115 is closed. When the brake switch 115 closes, it creates a short circuit across the terminals of the motor 20 . When on-off switch 110 is opened, power is no longer delivered to the motor 20 . However, the motor 20 continues to rotate and thus function as a generator. While the motor 20 operates as a generator, it produces current that is short circuited by the brake switch 115 . The short circuit inhibits current flow from the motor 20 which in turn causes the magnetic fields created by the windings to interfere with the magnetic fields of the surrounding permanent magnets, thereby inducing a braking force onto the drive shaft 60 and chuck 30 .
[0021] The control system also includes a fly wheel diode 200 which is electrically connected to the motor 20 . When current passes through the inductor 21 , yet the power MOSFET 130 is turned off, the current is dissipated through the flywheel diode 200 . Two diodes 210 , 220 may also be provided that prevent the power MOSFET 130 from turning off too quickly.
[0022] The power MOSFET 130 and microprocessor 120 are electrically connected to the control system. The microprocessor 120 cycles the power MOSFET 130 on and off to generate a PWM current/voltage to the motor 20 . The microprocessor 120 may be a commercially available microprocessor such as an eight pin microprocessor. The microprocessor 120 may be larger or smaller depending on the number of components or features of the tool 10 .
[0023] The control system 50 contains two voltage divider networks 170 - 172 and 180 - 182 that sense the voltage of electrical components of the tool. One voltage divider network 180 - 182 is electrically connected to the battery 40 , senses the voltage across the battery 40 and provides the battery voltage to the microprocessor 120 . Another voltage divider network 170 - 172 is electrically connected to the power MOSFET 130 , senses the voltage across the MOSFET 130 and provides the voltage across the power MOSFET 130 to the microprocessor 120 .
[0024] The control system 50 may also include a voltage regulator 140 that monitors and provides a stable operating voltage to the microprocessor 120 and other electrical components of the tool. The control system 50 may also include a potentiometer 150 which determines the maximum voltage from the voltage regulator 140 and based on the input from the trigger 80 determines and sends the maximum input voltage to the microprocessor 120 . The control system 50 may also include the audio output 160 . The audio output 160 may be a piezo-speaker or any other device that provides an audio signal to the user.
[0025] In operation, when the user presses the trigger 80 , the on-off switch 110 is closed and current flows from the battery 40 to the motor 20 (along and in the direction of path A). The microprocessor 120 determines the desired duty cycle based on the trigger 80 position. The microprocessor 120 monitors the voltage across the battery 40 and the power MOSFET 130 and determines if the desired duty cycle (based on the user input) exceeds a maximum safe output.
[0026] If the microprocessor 120 determines that the desired output is within a safe range then the actual duty cycle will be the desired duty cycle selected by the user. The control system 50 sends a PWM current/voltage signal to the motor 20 in accordance with the user selected duty cycle and the motor 20 drives the drive shaft 60 which turns the chuck 30 . If, however, the microprocessor 120 determines that the desired duty cycle is outside safe operating parameters, the microprocessor 120 will adjust the duty cycle to limit or eliminate damage to the battery 40 , motor 20 or power MOSFET 130 . After the microprocessor 120 determines a duty cycle within a safe operating range, the microprocessor 120 supplies a PWM current/voltage to the motor 20 by cycling the power MOSFET 130 on and off. When the user completely releases the trigger 80 the on-off switch 110 is opened.
[0027] By way of example only, the user may squeeze the trigger 80 to indicate a desire that the drive shaft 60 spin at 75% of its maximum rotation capacity. However, the microprocessor 120 may determine that a duty cycle associated with a drive shaft 60 rotational speed of 75% of the maximum speed is either not attainable or not desirable given the present condition of the battery 40 , present forces being induced on the drive shaft 60 , demands presently being placed on the motor 20 and power MOSFET 130 , and other considerations. Based upon these inputs, the microprocessor 120 may determine that a lower duty cycle associated with a rotation speed of less than 75% may be preferable. Accordingly, the microprocessor 120 may, by way of example only, drive the power MOSFET 130 to deliver a PWM current/voltage to the motor 20 only affording a rotation speed of approximately 50% of the maximum rotation speed for the drive shaft 60 .
[0028] The control system monitors and limits excessive currents being applied to the motor 20 , battery 40 , and other electrical components of the tool. The control system may also monitor a decreasing charge on the battery 40 and prevent discharging of the battery 40 below a certain level.
[0029] The microprocessor 120 monitors the battery 40 voltage and the voltage across the power MOSFET 130 through the voltage dividers 170 - 172 and 180 - 182 . These inputs allow the microprocessor 120 to determine the condition of the battery 40 and the current applied to the motor 20 . For example, the microprocessor 120 can detect excessive currents across the motor 20 , the battery 40 and other electrical components. When the microprocessor 120 detects an excessive current across the motor 20 , power MOSFET 130 or other electrical component, the duty cycle can be lower and thereby lowering the current to an acceptable level. The microprocessor 120 can also detect decreasing voltage in the battery 40 . When the microprocessor 120 detects a low voltage situation across the battery 40 , the microprocessor 120 can lower the duty cycle to reduce the voltage drain on the battery 40 .
[0030] The control system 50 also monitors the electrical conditions of the tool to determine if the tool 10 has stalled. Once the microprocessor 120 determines that the tool 10 is stalled it switches to a “ratchet mode” and changes the frequency at which the drive signal is supplied to the motor 20 . By changing the frequency of the drive signal, the control system maximizes the available current and increases the tools ability to eliminate the stalled condition.
[0031] For example, if the user squeezes the trigger 80 and the microprocessor 120 determines that a 50% duty cycle should be applied. The power MOSFET 130 is turning on and off in a pulse with modulation and is supplying current to the motor 20 50% of the time. When the power MOSFET 130 is on it is drawing a high current from the battery 40 , therefore the voltage across the MOSFET 130 is increasing and the voltage across the battery 40 is decreasing. This situation indicates that the tool is pulling a high current. Then in the next half cycle, the MOSFET 130 is turned off. If the motor 20 is not rotating, that is if there is no voltage generated across the motor 20 , then this situation indicates the motor 20 is in a stalled condition. When the microprocessor 120 detects a stalled motor 20 condition the microprocessor 120 will switch the tool 10 into a ratchet mode. In the ratchet mode, the microprocessor 120 changes the frequency at which current is supplied to the motor 20 . Stated another way, when in the ratchet mode, the microprocessor 120 lengthens the period or duty cycle. For example, during normal operation, the frequency may be 10 kHz which corresponds to a period of 0.1 milliseconds. During the ratchet mode, the frequency may be lowered to 1 Hz which corresponds to a period or duty cycle of 1 second.
[0032] By changing the frequency of the current to the motor 20 to a lower frequency, short high current bursts are delivered to the motor 20 . The ratchet mode operation reduces the amount of voltage drained from the battery 40 . The ratchet mode also increases the ability of the tool to eliminate the stalled motor 20 condition. In one embodiment, the microprocessor can be set to wait a predetermined number of cycles after the microprocessor 120 senses a stalled condition before the microprocessor 120 will switch into the ratchet mode.
[0033] [0033]FIG. 3 illustrates a series of graphs of voltages versus time for a) a tool only having on/off states, b) a tool controlled with PWM, and c) a tool controlled in a ratchet mode. As shown in FIG. 3, a tool operated in a ratchet mode delivers longer pulses at the on voltage to the motor, followed by longer periods of a zero or low voltage state.
[0034] Optionally, other components or measurements can be monitored to determine if the duty cycle or frequency (i.e., ratchet mode) of the tool should be adjusted by the microprocessor 120 . For example, the speed of the motor 20 could be monitored by the microprocessor 120 . Additionally, the speaker 160 may be used to indicate when either the duty cycle has been adjusted, when the tool is in ratchet mode, or when the battery 40 or another component needs to be changed.
[0035] Optionally, control system 50 may be used in other types of power tools, such as screw drivers, saws, and others.
[0036] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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A control system for driving a power tool is provided comprising a power source, a motor adapted to drive a shaft, a power switching unit interconnecting the power source and the motor, and a controller. The power switching unit applying a pulse width modulated (PWM) drive signal from the power source to the motor. The controller monitoring at least one electrical characteristic of at least one of the power source, motor and power switching unit and adjusting the operating duty cycle of the PWM drive signal based on the electrical characteristics.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a 371 of PCT/US98/03355 filed Feb. 20, 1998 and claims priority from Provisional Patent Application 60/039,151 filed on Feb. 20, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pharmaceutical compositions for application to the skin and to a method for the treatment of proliferating skin diseases. The composition may be applied topically. The treatment can be either therapeutic or prophylactic.
2. Description of Related Art
Proliferative skin diseases are widespread throughout the world and afflict millions of humans and their domesticated animals. This invention provides a method for treatment of such diseases. As used hereinafter in this specification and in the claims, the expression “proliferative skin diseases” means benign and malignant proliferative skin diseases which are characterized by accelerated cell division in the epidermis, dermis or appendages thereto, associated with incomplete tissue differentiation. Such diseases include: psoriasis, atopic dermatitis, non-specific dermatitis, primary irritant contact dermatitis, allergic contact dermatitis, basal and squamous cell carcinomas of the skin, lamellar ichthyosis, epidermolytic hyperkeratosis, premalignant sun-induced keratosis, non-malignant keratosis, acne, and seborrhic dermatitis in humans and atopic dermatitis in domesticated animals.
Heretofore, proliferative skin diseases have been generally accepted by mankind as an ongoing evil having degrees of severity variable with inherited skin traits and external factors but always have been recognized as unsightly, painful, morbid diseases. Over the history of mankind innumerable medicines and treatments have been proposed, tried and used with varying degrees of success.
Treatments which are prescribed and used for the treatment of proliferative skin diseases include the following:
(1) topical applications, e.g. coal tar derivatives, 5-fluorouracil, vitamin A acid, glucocorticoids in high dosage, bath oils and non-specific emollient creams and ointments; (2) systemic administration, e.g. glucocorticoids and classic anti-cancer agents, for example, methothrexate, hydroxyurea, azaribine, cyclophosphamide; and (3) physical modalities, e.g. ultra violet light, x-radiation, and, in severe cases, surgery.
While these treatments provide, in certain cases some remission of the original symptoms, each treatment suffers some defect, for example, temporary and incomplete mitigation of symptoms, rapid re-occurrence of the disease when mitigation is terminated, serious and sometimes irreversible damage (atrophy) resulting from the topical application for extended times of glucocorticoids, acute bone marrow suppression, cirrhosis of the liver resulting from the protracted use of methothrexate which may lead to death of the patient, and the causation of cancer by the application of anti-cancer drugs, x-radiation, or ultra violet rays.
Recently, a new compound has been approved by the Food and Drug Administration for the treatment of psoriasis and acne. Tazarotene. Tazarotene is available as Tazorac® 0.1% and Tazorac® 0.05% topical gel from Allergan, Inc. of Irvine, Calif.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a method of treating psoriasis in humans with tazarotene, preferably a gel comprising 0.1%, tazarotene by weight, and a corticosteroid, preferably a cream. The tazarotene gel may be administered once daily in the evening and the corticosteroid cream may be administered to the subject once daily in the morning, or the gel and cream may be administered on alternate days. The tazarotene gel is disclosed in U.S. patent application Ser. No. 623,184, which is entitled “Stable Gel Formulation for Topical Treatment of Skin Conditions”, which was filed on Mar. 28, 1996, in the name of Prakash Charu and is hereby incorporated by reference in its entirety.
In one aspect of the invention, the corticosteroid may be Synalar® cream (0.01% fluocinolone acetonide), Elocon® cream (0.1% mometasone furoate) or Lidex® cream (0.05% fluocinonide), i.e. a low-potency, mid-potency and high-potency corticosteroid, respectively.
In another aspect of the invention, the corticosteroid may be fluocinonide 0.05% ointment, Lidex®, a high potency steroid, mometasone fuoate 0.1% ointment, Elocon®, a high potency steroid, diflorasone diacetate 0.05% ointment, Maxiflor®, a high potency steroid, fluticasone propionate 0.005% ointment, Cultivate®, a mid-potency steroid, betamethasone dipropionate 0.05% cream, Diprosone®, a mid-potency steroid, diflorasone diacetate 0.05% cream, Maxiflor®, a mid-potency steroid, clobetasol propionate 0.05% ointment, Temovate®, a super-potency steroid, betamethasone valerate 0.1% lotion, Valisone®, a mid-potency steroid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph comparing the reduction in plaque elevation over a 12 week treatment period with tazarotene in combination with placebo, high-potency corticosteroid, mid-potency corticosteroid and low-potency corticosteroid.
FIG. 2 shows the treatment success with the combination therapies of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
In accordance with this invention it has been found that proliferative skin diseases are alleviated, that is, the symptoms of the disease are noticeably improved or become undetectable, by the treatment of the afflicted patient, or animal, with the pharmaceutical compounds described in detail, hereinbelow.
For the purposes of this specification and the claims, a proliferative skin disease is alleviated when there is a noticeable decrease in the thickness of a lesion to palpation, with or without residual redness, or residual slightly dilated blood vessels or residual hyper- or hypo-pigmentation. For purposes of this invention and the claims hereof, psoriasis is alleviated when a scale-free psoriasis lesion is noticeably decreased in thickness, or noticeably but incompletely cleared or completely cleared.
The compositions utilized in the method of this invention may be applied topically.
The term “topical” as employed herein relates to the use of the active ingredient incorporated in a suitable pharmaceutical carrier, and applied at the site of the disease for exertion of local action. Accordingly, such topical compositions include those pharmaceutical forms in which the compound is applied externally by direct contact with the skin surface to be treated. Conventional pharmaceutical forms for this purpose include ointments, lotions, pastes, jellies, sprays, aerosols, bath oils and the like. The term “ointment” embraces formulations (including creams) having oleaginous, absorption, water-soluble and emulsion-type bases, e.g., petroleum, lanolin, polyethylene glycols, as well as mixtures thereof. Topical application with occlusion of an area larger than the medicated area may produce improved results relative to non-occluded topical applications.
The percentage by w/w of the active ingredient, i.e. the corticosteroid herein utilized ranges from about 0.001% to about 1% of the pharmaceutical preparation, preferably from about 0.005% to about 0.1%, by weight.
The percentage by w/w of the active ingredient, i.e. tazarotene herein utilized ranges from about 0.01% to about 15% of the pharmaceutical preparation, preferably from about 0.1% to about 2% and in these preparations the aforesaid pharmaceutical carrier for topical application constitutes a major amount of the said preparation.
Preferably tazarotene is utilized as a stable gel formulation for topical treatment of skin conditions in humans, said stable gel formulation comprising: Ethyl-6-[2-(4,4-dimethylthiochroman-6-yl)ethynyl]nicotinate in a plurality of nonaqueous vehicles for both solubilizing tazarotene and forming a gel therewith, said nonaqueous vehicles enabling topical application of the gel to a skin condition, said plurality of vehicles each being present in amounts, and in combination, to control release of tazarotene from the gel to the skin conditions. In the tazarotene formulation the vehicles are present in amounts selected to produce maximum release of the active agent, i.e. tazarotene, from the gel when all the vehicles are present therein. Preferably the formulation comprises three vehicles and more preferably the formulation comprises three vehicles which are used to both solubilize the active agent and form a gel.
The formulation preferably comprises the three vehicles, e.g. Polysorbate 40, Poloxamer 407 and Hexylene glycol. Polysorbate 40 is
wherein the Sum of w, x, y, and z is 20 and R is (C 15 H 31 )COO and Poloxamer 407 is HO(C 2 H 4 O) a (C 3 H 6 O) b (C 2 H 4 O) a H having the following properties.
USAN for Poloxamers
BASF
Corp.
Average
Average
Brand
Physical
Molecular
Values
Name
Poloxamer
Form
Weight
a
b
Pluronic
124
Liquid
2090 to 2360
12
20
L 44
188
Solid
7680 to 9510
80
27
F 68
237
Solid
6840 to 8830
64
37
F 87
338
Solid
12700 to 17400
141
44
F 108
407
Solid
9840 to 14600
101
56
F 127
More preferably, tazarotene is utilized as a stable gel formulation for topical treatment of psoriasis comprising an effective amount of Ethyl-6-[2-(4,4-dimethylthiochroman-6-yl)ethynyl]nicotinate in a pharmaceutical carrier comprising:
(a)
water;
(b)
edetate disodium;
(c)
ascorbic acid;
(d)
Carbomer 934P;
(e)
Poloxamer 407;
(f)
polyethylene glycol;
(g)
Polysorbate 40;
(h)
hexylene glycol;
(i)
butylated hydroxytoluene;
(j)
butylated hydroxyanisole;
(k)
benzyl alcohol; and
(l)
tromethamine.
The tazarotene formulation may comprise Polysorbate 40 in an amount up to about 0.4% by weight, Poloxamer 407 in an amount up to about 0.4% by weight, and hexylene glycol in an amount up to about 2% by weight or more preferably Polysorbate 40, in an amount of about 0.32% by weight, Poloxamer 407 in an amount of about 0.18% by weight, and hexylene glycol in an amount of about 2% by weight.
Most preferably, the tazarotene formulation comprises:
CONCENTRATION
INGREDIENT
FUNCTION
% W/W
tazarotene
Drug
0.1
purified water
Excipient
49.25
Edetate Disodium
Stabilizer
0.05
Ascorbic acid
Stabilizer
0.05
Carbomer 934P 1
Thickening
1.25
agent
Poloxamer 407
Surfactant
0.2
PEG-400
Co-solvent
45.0
Polysorbate 40
Surfactant
0.2
Hexylene glycol
Co-solvent
2.0
Butylated
Stabilizer
0.05
hydroxytoluene
Butylated
Stabilizer
0.05
hydroxyanisole
Benzyl alcohol
Preservative
1.0
Triethanolamine/
Neutralizer
0.8
Tromethamine
1 Carbomer 934P [1975]. NF. The viscosity of a neutralized 0.5 percent aqueous dispersion of Carbomer 934P is between 29,400 and 39,400 centiposes. (1) Polymer of 2-propenoic acid, cross-linked with allyl ethers of sucrose or pentaerythritol; (2) Polymer of acrylic acid, cross-linked with allyl ethers of sucrose or pentaerythritol. Molecular weight is approximately 3,000,000.
The tazarotene formulation and the corticosteroid formulation, each, will be applied, topically, in an amount to achieve the maximum effect on alleviating the proliferative skin disease symptoms without causing an adverse reaction. Selection of such an amount of either formulation is well within the skill of the art.
Preferably, the tazarotene formulation is utilized to provide from about 0.5 to about 5 mg of tazarotene per cm 2 of affected skin, more preferably from about 1 to about 3 mg/cm 2 , e.g. 2 mg/cm 2 .
The method of this invention also employs a corticosteroid. The expression “corticosteroid” refers to a naturally occurring product of the adrenal cortex, or a synthetic analog thereof possessing anti-inflammatory activity and minimal or no mineralocorticoid activity or sex steroid activity. The corticosteroids include glucocorticoids. Of the natural glucocorticoids, one may use for example, hydrocortisone or the synthetic glucocorticoids such as methyl prednisolone acetate (Prednisone) or triamcinolone for topical therapy. The corticosteroids are preferably employed in amounts of from 0.5 to 5 mg per cm 2 of affected skin, more preferably from about 1 to 3 mg/cm 2 , e.g. 2 mg/cm 2 .
The treatment period may be 12 weeks with a 4 week follow-up period. The subjects are evaluated for plaque elevation, scaling and erythema with a successful treatment defined as about 50% improvement or better. During the treatment period, tazarotene in combination with the mid- or high-potency corticosteroid produced significantly better results than treatment with tazarotene in combination with placebo in reducing plaque elevation, scaling, erythema and overall severity. During the 4 week post-treatment period, the results with tazarotene plus mid- or high-potency corticosteroid were equal to or better than tazarotene plus placebo or tazarotene plus low-potency corticosteroid.
The most common adverse events resulting from the treatment were burning, pruritus and erythema; however there was a lower incidence of such adverse events in patients treated with tazarotene plus the medium- or high-potency corticosteroid.
Thus, treating psoriasis in humans with a combination of tazarotene and a mid-potency or high-potency corticosteroid is more effective than a combination of tazarotene and low-potency or placebo and results in a lower incidence of adverse events such as burning pruritis and erythema.
The invention is further illustrated by the following examples which are illustrative of various aspects of the invention, and are not intended as limiting the scope of the invention as defined by the appended claims.
EXAMPLE 1
The study reported here utilizes a combination regimen that alternates between tazarotene 0.1% gel and a corticosteroid or placebo cream every evening. The aim of the study was to determine whether such alternating therapy may offer clinical benefits by maximizing the therapeutic benefits of both drugs, while also minimizing corticosteroid use and thus reducing the potential for adverse corticosteroid-induced effects.
This study was a multicenter, investigator-masked, parallel-group study, enrolling 398 patients with stable plaque psoriasis. Topical applications of tazarotene 0.1% gel, were administered every other evening, and one of the following creams administered on alternate evenings): placebo; low-potency corticosteroid (hydrocortisone acetate 1%); medium-potency corticosteroid (alclometasone dipropionate 0.05%); or high-potency corticosteroid (betamethasone valerate 0.1%).
The study required a 12-week treatment period plus a 4-week follow-up phase. The patient demographics included 388 patients (231 male and 157 female) with evaluable data, mean age of 46.7 years (range: 21–88 years) and a mean duration of psoriasis of 17.39 years.
All treatment groups achieved clinically significant reductions in plaque elevation at all treatment and post-treatment visits, with the tazarotene/high-potency combination taz/high group achieving consistently greater reductions than the other treatments throughout the study. At week 4, these reductions were significantly greater than those in all the other treatment groups. The taz/high also achieved clinically significant reductions in plaque elevation more rapidly than the other treatments, i.e. in two weeks compared with four weeks in all the other groups. (See the results set forth in FIG. 1 .)
Treatment success was defined as a moderate, marked, almost clear or completely cleared response (≧50% global clinical improvement). All tazarotene/corticosteroid treatment groups achieved treatment success rates of >50% within 4 weeks. However, the taz/high combination achieved significantly greater treatment success rates than the tazarotene/placebo (taz/plac) and tazarotene/medium-potency corticosteroid (taz/med) combinations throughout the 12-week treatment period. Peak treatment success rates ranged from 56% (for patients treated with taz/plac at Week 8) to 77% (for taz/high at Week 8).
During the 4-week follow-up period, all groups retained ≧60% global clinical improvements in psoriasis, with treatment success rates ranging from 60% (for taz/med) to 75% (for taz/high) at study Week 16. These improvements were statistically and clinically significant compared with the pretreatment levels and there were no significant differences between the groups at the end of the follow-up period. (See FIG. 2 .)
Week 12, the probability of patients being considered a treatment success at any study visit was 77% in the taz/high group. In the other groups the treatment success was 56 to 61%.
The taz/high combination also achieved initial treatment success significantly faster than any of the other combinations. The median time to treatment success was 2 weeks in the taz/high group, compared with 4 weeks in each of the other groups.
All treatment groups achieved clinically significant reductions in scaling during the treatment period, and the taz/high combination was consistently the most efficacious treatment throughout the 12-week treatment period. The reductions in scaling achieved in all groups by the end of the treatment period were generally maintained during the 4-week follow up period.
All treatment groups achieved statistically significant reductions in erythema during the treatment period and, once again, the taz/high combination was the most efficacious treatment. During the follow-up period, all groups retained significant reductions in erythema compared with baseline levels, and these reductions were clinically significant in the taz/high, taz/med, and taz/plac groups.
The overall incidence of adverse events that were possibly, probably or definitely treatment-related decreased with increased corticosteroid potency, falling from 42% in the taz/plac group, to 36%, 32% and 31% in the tazarotene/low-potency corticosteroid (taz/low), taz/med, and taz/high groups, respectively. (See Table II, below.)
TABLE II
Overall incidence of adverse events
Patients (%).
Taz/plac
Taz/low
Taz/med
Taz/high
Pruritus
15
19
16
8
Erythema
12
7
6
6
Irritation
8
9
5
4
Burning
6
4
4
8
In view of the above Example, the following conclusions may be drawn. Alternate-day treatment with tazarotene 0.1% gel and the high potency corticosteroid cream was consistently more effective than the other three regimens in reducing plaque elevation, scaling and erythema. Patients in the tazarotene plus high-potency corticosteroid group also achieved significantly higher treatment success rates (≧50% global clinical improvement, and achieved treatment success faster, than patients in the other groups. Treatment-related adverse events comprised mainly mild to moderate local irritation including pruritus, erythema and burning skin. The incidence of treatment-related adverse events decreased as the potency of the corticosteroid cream used increased.
EXAMPLE 2
The study of Example 1 is substantially repeated with fluocinolone acetonide 0.01% cream (low-potency), mometasone furoate 0.1% cream (mid-potency) and fluocinonide 0.05% cream (high-potency) used as the corticosteroids. In this study tazarotene 0.1% gel in combination with a mid-potency or high-potency corticosteroid, when compared with tazarotene plus placebo cream, was associated with significantly higher treatment success rates, significantly greater reductions in scaling, erythema, and overall lesional severity, with a decreased incidence of adverse events. The corticosteroids are Synalar® cream, Elocon® cream and Lidex® cream, respectively.
While particular embodiments of the invention have been described, it will be understood of course that the invention is not limited thereto since many obvious modifications can be made and it is intended to include within this invention any such modifications as will fall within the scope of the appended claims.
Having now described the invention, I claim.
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The present invention provides a method for treating proliferative skin diseases comprising the administration of an effective amount of tazarotene and an effective amount of a corticosteroid. This invention is especially useful for treating psoriasis.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 13/626,057 filed Sep. 25, 2012, and claims priority to U.S. Provisional Application Ser. No. 61/846,270 filed on Jul. 15, 2013.
BACKGROUND
This disclosure generally relates to method and device for creating a linked item. More particularly, this disclosure relates to a method and device for creating a linked wearable item from elastic bands.
Kits that include materials for making a uniquely colored bracelet or necklace have always enjoyed some popularity. However such kits usually just include the raw materials such as different colored threads and beads and rely on the individual's skill and talent to construct a usable and desirable item. Accordingly there is a need and desire for a kit that provides not only the materials for creating a unique wearable item, but also that simplifies construction to make it easy for people of many skill and artistic levels to successfully create a desirable and durable wearable item.
SUMMARY
A Brunnian link is a link formed from a closed loop doubled over itself to capture another closed loop to form a chain. Elastic bands can be utilized to form such links in a desired manner. The example kit and device provides for creation of Brunnian and other linked articles. Moreover, the example kit provides for the successful creation of unique wearable articles using Brunnian and other link assembly techniques.
The example kit includes a template for mounting an initial band and a hook utilized for attaching additional bands to the initial bands placed on the template. The template includes pins that hold the initial band in place while additional bands are linked onto each other. The kit further includes a clip utilized to attach ends once the desired length is formed.
These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 perspective view of an example kit for creating a linked article.
FIG. 2 is schematic view of link article.
FIG. 3 is a schematic view of a series of a series of Brunnian links.
FIG. 4 is a side view of an example template.
FIG. 5 is an end view of the example template.
FIG. 6 is a top view of the example template.
FIG. 7 is a plan view of an example clip for securing loose ends of a Brunnian linked article.
FIG. 8 is perspective view illustrating elastic bands secured with the example clip.
FIGS. 9A-9M are views of an example method of creating a linked article using the example template and kit.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , an example kit is indicated at 10 for creating linked items such as bracelets, necklaces and other wearable or decorative article as generally indicated in FIG. 2 . The example kit 10 includes a template 12 , a clip 16 and a hook 14 . The example kit 10 also includes a number of elastic members 18 that are used with the kit 10 to form links for the resulting wearable article. The elastic members 18 are consumed as articles are fabricated, and are replaced and replenished with additional elastic members. Moreover, the example elastic members 18 are of a size corresponding with the example template 12 . Further, although a single clip 16 is illustrated, the example kit 10 will include many clips 16 to provide for the fabrication of many articles 26 .
Referring to FIG. 3 , a Brunnian link 20 is formed from a continuous looped structure without forming an actual knot. Several links 20 are formed in a chain to form a circular structure. Ends 22 of each elastic member 18 are secured and a durable wearable article is created. In this example three links 20 are shown forming a single chain. Each link 20 is formed by capturing the ends 22 of one loop structure with a mid portion 24 of another loop structure in series. Each link 20 depends on the previous and subsequent links 20 to maintain the desired shape and integrity. Removing one link 20 results in all of the links becoming loose from each other.
Referring to FIGS. 4 , 5 and 6 , the example template 12 includes two posts 28 A, 28 B spaced a distance 30 apart from each other. Each of the pins 28 A, 28 B includes a first arm 32 a - b and second arm 34 a - b supported on a base 36 . The arms 32 a - b , 34 a - b defines an access slot 38 that extends across both of the posts 28 A, 28 B. The base 36 includes a link opening 40 for completed links of a linked article during fabrication. Each of the first and second arms 32 a - b , 34 a - b include upper and lower tabs 42 that maintain a linked article within a center section 44 .
Referring to FIGS. 7 and 8 , the example clip 16 is generally C-shaped with inwardly facing ends 48 . The inwardly facing ends 48 point inwardly to an open space 50 where parts of the elastic members are kept 18 . The inwardly facing ends 48 prevent ends 22 from sliding out from the inner area 50 off of the clip 16 .
Referring to FIGS. 9A-M , the example template 12 is utilized for the formation of a linked article. As appreciated, elastic bands 18 can be difficult to manipulate and hold during the construction of a desired article. The example template 12 provides for holding of an initial number of links 20 and subsequent connection of each link in the linked article. The template 12 includes the first and second posts 28 A, 28 B along with the access slot 38 across both of the posts 28 A-B. The specific linked configuration can be a simple Brunnian link, but may also be more complex and intricate link structures such as a fishbone type link structure. The template 12 includes the link opening 40 to facilitate the fishbone link structure where the linked article grows and extends from the template 12 through the link opening 40 .
The Figures illustrate formation of a fishbone linked structure utilizing the example template 12 . The initial step illustrated in FIG. 9A includes assembling a first elastic band 18 A by crossing over itself to form a FIG. 8 pattern across the posts 28 a - b . A second elastic band 18 B and third elastic band 18 C is then assembled over the first elastic band 18 A without crossing over as is shown in FIG. 9B . Three elastic bands are therefore supported across the posts 28 a - b with the first band 18 A on the bottom below the second and third elastic bands 18 B, 18 C.
Utilizing the hook tool 14 , the bottom, lower most, or first elastic band 18 A is pulled off of the posts 28 A-B and looped over the second and third elastic bands 18 B, 18 C as is shown in FIGS. 9C and 9D . The first elastic band 18 A is positioned to loop around each of the second and third elastic bands 18 B, 18 C and is not supported directly by the posts 28 a - b.
An additional elastic band 18 D is then added above the second and third elastic bands 18 B, 18 C such that the second elastic band 18 B is now the lower most elastic band as is shown in FIG. 9E . The lower most elastic band 18 B is then grasped with the hook tool 14 ( FIG. 9F ) by extending the hook tool 14 into the access slot 38 and grasping ends of the elastic band in sequence, pulling the ends away from the corresponding post ( FIG. 9G ) and looping each end over onto the and around the other links supported between the first and second posts as is shown in FIG. 9H .
An additional link is added above the two remaining links 18 C, 18 D across the two posts 28 a - b as is shown in FIG. 9I and the process shown in FIGS. 9F through 9H is repeated with additional links to grow the length of the linked structure as is shown in FIGS. 9J and 9K until a desire length or number of links are connected to each other as is illustrated in FIG. 9L .
Once the desired length is achieved, as the example in FIG. 9L illustrates a clip 16 is attached to the end elastic link. The remaining links on the posts 28 a - b can be removed and attached to the clip 16 to form the completed linked article as is shown in FIG. 9M . As appreciated although the ends are connected to form the example linked article. The linked article may have terminal ends that are separately terminated to provide a length of a linked article.
Accordingly, the example kit and method provide for the creation of many different combinations and configurations of linked structures and articles for the creation of bracelets, necklaces, and other wearable items. Moreover, the example kit is expandable to further create and expand the capabilities of potential linked structures and articles. Further, the example kit provides for the creation of such links and items in an easy manner allowing persons of varying skill levels to be successful in creating unique wearable items.
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this invention.
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A disclosed device for creating an item consisting of a series of links includes at least two posts spaced part from each other in a first direction with each of the posts including a first arm and a second arm and an access slot.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation-in-Part of U.S. Ser. No. 10/0918,375, filed Aug. 16, 2004, which claims priority of DE 202004011087.3, filed Jul. 15, 2004, which applications are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a seat backing, Specifically, the present invention relates to a hollow seat backing having a particularly designed seat- and bearing region. A generic seat backing is already known from EP 705549 B1.
RELATED INFORMATION
[0003] Various seat backings are known which are bolster-like and are therefore also referred to as seat bolsters. Such seat bolsters are either filled with elastic or resilient materials such as feathers, foam or the like, or their elastic stiffness is achieved by an enclosed fluid- or gas volume such as water or air. Also known are so-called seat bolsters which have a special wedge-shaped design and hence provide an inclined sitting face. From EP 1342434 A1, a wedge-shaped seat backing is already known. The existing elasticity of the seat backing was intended to allow the sitting person to sit in a dynamic, active and hence back muscles-strengthening manner. The special design of the seat bolster, which has a wedge-shaped cross section, pushes the pelvis to the front and supports an upright and hence correct sitting posture. Consequently, this design prevents back problems and corrects false posture.
[0004] These known seat backings lead, however, to an ergonomically incorrect sitting posture and to incorrect active or dynamic sitting, as they comprise a direct, substantially vertical face having a low elastic concavity or curvature in the junction region between the sitting face and the bearing face. This vertical joining region of the seat backing does not allow a sufficient movement mobility of the sitting person when the pelvis moves laterally or forwards and backwards. These movements are also known for so-called sitz balls where the latent slight instability of the sitting position forces the body to make continuous compensating movements. Consequently, the back muscles are strengthened and positional failures or back problems and relevant diseases are prevented.
SUMMARY OF THE INVENTION
[0005] Therefore, the present invention provides a seat backing which stands out for simple design and handling and which effects an ergonomically advantageous sitting position or posture of the person sitting thereon and also promotes dynamic sitting as is known to be advantageous and simultaneously allows tilting of the pelvis. It is further intended that the seat backing should provide a stable as well as largest possible sitting area for persons.
[0006] According to an aspect of the invention, a seat backing having an inclined sitting face is provided. The seat backing comprises a closed hollow plastic jacket which defines a chamber fillable with a fluid.
[0007] The fluid in the chamber is fed by means of a valve which is located on the plastic jacket and is integrated therein. The seat backing comprises a bearing region and a sitting region which is intended for receiving the sitting person. The bearing region and the sitting region are connected to a transition region provided therefor. The inclination of the sitting region in comparison with the bearing region according to the invention produces a top or upper and a bottom or lower sitting section of the sitting region. The inclination of the sitting region with respect to the bearing region according to the invention allows a slightly inclined sitting posture which fits in with the needs and habits of the sitting person which facilitates rocking of the spine of a person sitting on the sitting region proximate to the upper sitting region while substantially fixing the legs of the person sitting on the sitting region. The transition region according to the invention comprises an upper section and a lower section which are respectively formed around the sitting and bearing regions so that these sections mainly enclose the bearing face and the sitting face integrally and interconnect them. The faces of the upper and lower sections according to the present invention define in the upper and in the lower sitting region at least partially a sitting face which is increased when the seat backing is used, as the user deforms by his/her weight the transition region and uses the sitting region as a sitting face.
[0008] The inclined face of the sitting region causes a greater elastic deformation of the transition region for a same weight of the user as compared with conventional seat backings or hollow bodies, namely particularly in the upper sitting region and the upper section of the transition region.
[0009] It is preferred that the angle between the sitting region and the bearing region is about 4° to about 30°, particularly preferably about 4° to 14°. In this angle range, ergonomically particularly preferred elastic compensation movements of the body have been observed.
[0010] It is preferred that the bearing region is defined substantially symmetrically to the sitting region. This is preferred in terms of the manufacturing technology and produces a homogeneously curved transition region.
[0011] It is preferred that the area of the transition region of the upper section is substantially larger than the area of the transition region of the lower section. This serves the purpose of providing for application of a higher load in the upper sitting region.
[0012] It is preferred that the transition regions formed around the sitting face and the bearing face has a cross section of which at least some sections are curved or bent. A preferred design has continuous transitions.
[0013] It is preferred that the transition region formed around the sitting face and the bearing face has a cross section of which at least some sections are non-curved or have at least one straight section in the cross section. This allows a design in which plural straight sections are interconnected at an angle.
[0014] It is preferred that the transition region forms a continuous marginal edge in the region of the lower sitting section to provide a low height dimension.
[0015] It is preferred that the seat backing is at least partially made of thermoplastic plastic. This is preferred in terms of the manufacturing technology.
[0016] It is preferred that the plastic jacket has protrusions made of the same material. It is preferred that the protrusions made of the same material result in improved elastic properties of the seat backing.
[0017] Alternatively, it is preferred that the protrusions made of the same material produce a slip-resistant profile.
[0018] It is preferred that the surface of the plastic jacket comprises a slip-resistant surface in predetermined regions of the sitting region or bearing region.
[0019] It is preferred that the sitting region and the bearing region are substantially flat in the unloaded state. This prevents bulging and a deformation of the faces which is unfavorable to convenience. Moreover, a flat or substantially flat design provides an elastic deformation of the transition region.
[0020] It is preferred that in the unloaded state the transition region, in the upper sitting region, substantially comprises a curved cross section or a cross section of which at least some sections are straight and in the lower sitting region, two partial regions meet in an acute angle and form an edge.
[0021] It is preferred that the cross section of the seat backing is 25 cm to about 50 cm, particularly preferably 30 to 45 cm, and most preferably 35 to 40 cm.
[0022] It is preferred that the height of the upper sitting region is 4 cm to about 15 cm.
[0023] It is preferred that the height of the lower sitting region is 0 cm to about 4 cm.
[0024] Other objects, advantages and features of the present invention will be apparent from the following exemplary description of preferred embodiments with reference to the accompanying drawings. Like reference numerals identify like parts throughout the drawings.
[0025] A seat backing formed by a closed hollow plastic jacket defining a chamber fillable with a fluid and a valve provided in the jacket, serving for feeding the fluid to the chamber in accordance with the invention includes a bearing region intended for putting on a seat; a sitting region intended for receiving a sitting person which is inclined relative to the bearing region when placed on the seat; and a transition region formed between the bearing and the sitting region and interconnecting the regions; and wherein the sitting region comprises an upper sitting region which is proximate a spine of a person sitting on the sitting region and a lower sitting region which is proximate the legs of the person sitting on the sitting region; the transition region comprises upper and lower sections which are joined to define a periphery of the hollow plastic jacket and which extend inwardly from the periphery to join the sitting region and the bearing region and which sitting and bearing regions are separated only by the fluid with a distance of separation inside the jacket when filled with fluid between the upper and lower sections increasing from a minimum spacing at the lower sitting region toward the upper sitting region to a greater spacing whereby the person sitting on the sitting region may rock the spine forward and backward to vary the distance of separation between the upper and lower sections to a greater extent proximate the upper sitting region than proximate the lower sitting region; and the hollow plastic jacket is elastic so as in response to movement of the person sitting on the sitting region causes the periphery to increase to provide additional sitting region and bearing region area. An angle between the sitting region and the bearing region may be about 4° to about 30°. The angle may be about 4° to 14°. The bearing region may be defined substantially symmetrically to the sitting region of the transition region. The upper transition region may be a larger area than an area of the lower transition region which provides a greater flexibility between the sitting and bearing regions at upper transition areas than at the lower transition areas. The transition region may be a cross section with at least some part thereof is curved, bent or non-curved or has at least one straight section therein. The transition region may form a continuous marginal edge in a region of the lower section. The seat backing may at least partially be made of thermoplastic plastic. The plastic jacket may have protrusions made of a same material as the plastic jacket. The protrusions made of the same material may produce a slip-resistant profile. A surface of the plastic jacket may comprise a slip-resistant surface in regions of the sitting region or bearing region. The sitting region and the bearing region may be substantially flat in an unloaded state. In the unloaded state the transition region, the upper section may comprise a curved cross section or a cross section of which at least some sections are straight, and in the lower section, two regions may meet in an acute angle and form an edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a side view of the seat backing according to the invention.
[0027] FIG. 2 is a top view of the seat backing according to the invention.
[0028] FIG. 3 is another top view of another embodiment of the seat backing according to the invention, the circumference not being formed circularly or elliptically.
[0029] FIG. 4 is another side view of another embodiment.
[0030] FIG. 5 is another side view of another embodiment according to the invention.
[0031] FIG. 6 is another side view of another embodiment according to the invention.
[0032] FIG. 7 is another side view of another embodiment according to the invention.
[0033] FIG. 8 is another side view of the invention.
[0034] FIGS. 9 and 10 respectively illustrate a view of seat backing placed on a chair illustrating an unloaded state and a loaded state including the dynamic operation of the seat backing illustrated in phantom in FIG. 9 in response to movement of the spine of a person sitting on the chair in FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] FIG. 1 shows the seat backing according to the invention in the side view. The seat backing has three main faces: a sitting face, a bearing face and a junction face which serves as a transition region. The seat backing provides two sitting sections which are defined according to the invention on the sitting face: an upper sitting region OS and a lower sitting region US. The dotted axes T-T′ and A-A′ illustrate the arrangement of the respective regions. With reference to FIG. 1 , the transition region in the upper sitting region according to the invention is located to the left of the axis T-T′, whereas the transition region in the lower sitting region is located on the right-most side of FIG. 1 . The transition region is divided into two partial regions: the sitting region STB and the bearing region ATB. These partial regions connect according to the invention the bearing face to the sitting face. The sitting partial region and the bearing partial region are concentrically formed around the respective sitting o r bearing faces to form a circular o r elliptical shape. Due to their special design, the faces of the partial regions contribute at least partially to the sitting region of the seat backing when the seat backing is used. The elastic properties of the plastic jacket and the fed-in fluid allow the transition region to bulge or increase “outwardly” to form an additional area for sitting or bearing as illustrated by phantom lines in FIG. 9 . This effect produces dynamic sitting which is similar to well-known sitz balls without a risk of rolling away.
[0036] Due to the inclined embodiment according to the invention, the required area of the sitting partial region and that of the bearing partial region are, in the acute-angled (lower) portion of the seat backing, smaller than in the region of the upper sitting section.
[0037] When the sitting person uses the seat backing according to the invention, he/she can select in which sitting region he/she wants to sit. Alternating the upright position as illustrated in FIG. 10 or the bearing places of the seat in the different sitting sections produce a so-called training effect whereby the back muscles are strengthened. In general, the embodiment according to the invention supports the horizontal and vertical movements of the pelvis and spine as illustrated in FIG. 10 to allow dynamic or active sitting. The diameter of the seat backing D is 20 to 50 cm, preferably 30 to about 45 cm, and most preferably about 35 to 40 cm. The height H 1 of the upper sitting section is preferably 4 to about 15 cm, and particularly preferably about 5 to 7 cm. The height H 2 of the lower sitting section is preferably 0 to about 4 cm, and particularly preferably about 1 to 3 cm. The embodiment according to the invention produces an inclination angle W between the bearing face and the sitting face. This inclination angle is 40 to about 300, particularly preferably 4 to 14°. The arrow drawn by an extra-bold line is intended to symbolize the horizontal axis of the seat on which the seat backing is laid for use.
[0038] FIG. 2 shows a top view of the sitting face of the seat backing according to the invention. In this embodiment according to the invention, the diameter D is the diameter in the circular top view. The dimension of the diameter is given in FIG. 1 . The concentric circles form one possible arrangement of protrusions according to the invention which make the surface of the sitting face slip-resistant. Similar or equal protrusions may be preferably provided on the bearing region to achieve a similar effect with respect to the seat. The hatched concentric area shows that the transition region around the seat backing has a special design. In FIG. 2 , the sitting partial region STB is shown, but the bearing partial region (not shown) is analogously formed around the seat backing on the bearing face. The reference symbol V symbolically shows one possible arrangement of the valve for feeding the fluid. The valve is preferably arranged in the upper sitting region, particularly preferably near the transition region.
[0039] FIG. 3 is another top view of an embodiment according to the invention. I n this case, the sitting region or bearing region no longer has a circular or elliptical shape but is formed in a rounded manner on one side and is formed in a rectangular manner with rounded corners on the other side. The diameter of the semicircle which was used to form the seat backing is given the same dimension as in FIG. 1 . The circularly shaped corners of the upper sitting section have radii R 2 . In this embodiment according to the invention, the radius R 2 is 2 to 12 cm, preferably 4 to 7 cm, particularly preferably about 6 cm.
[0040] FIG. 4 is another side view of another seat backing according to the invention, some protrusions ANF made of the same material being shown symbolically. These protrusions may have different properties. On the sitting face and on the bearing face, they contribute to the slip resistance of the seat backing with respect to the sitting person or the seat. Similar protrusions on the sitting face or further in the transition region may also be provided for massage purposes. The arrangement of the protrusions in this figure are intended as a non-restricted example.
[0041] The FIGS. 5, 6 and 7 are an additional three possible embodiments of the seat backing in the side view. They are three possible embodiments of the connecting transition region and also show one possible non-symmetrical structure. In FIG. 5 , a uniformly curved transition region is provided in an oval form. In FIG. 6 , a transition region is shown which forms an angle of substantially 90° at the base and changes towards the top from a straight into a slightly rounded shape. Alternatively, a transition region having plural bosses or shoulders is shown in FIG. 7 . The special shape of the transition region forming the shallow-out face of the sitting or bearing face allows to maintain the property of the increased sitting area. That is, the transition region contributes to the sitting area during use. The protrusions schematically represented in FIG. 7 may have another shape as well.
[0042] In FIG. 8 , a transition region is represented schematically which shows a trapezoidal shape with plural adjacent straight lateral faces which form an obtuse angle and have rounded edges.
[0043] FIGS. 9 and 10 respectively illustrate the seat backing of the invention positioned for intended use of a person sitting in the chair on which the seat backing is placed and the dynamic elastic deflection of seat backing when a person is sitting on the chair and rocks the spine forward and backward or side to side. The dotted line of the profile of FIG. 9 illustrates the bulging of the transition region outwardly when a person is in a sitting position of FIG. 10 which increases the area of the sitting region and bearing region. The dynamic bulging produces dynamic sitting of the well-known sitz ball which is facilitated by the elastic property of the hollow plastic jacket without a risk of rolling away. The dynamic movements illustrated by the solid line and dotted line profile of the person's spine facilitate a person sitting on the sitting region rocking the spine forward and backward or side to side to vary a distance of separation between the upper and lower sections to a greater extent proximate the upper sitting region than proximate the lower sitting region. The elastic property of the hollow plastic jacket causes the periphery of the seat backing to provide additional sitting region area and additional bearing region area and is flexible so as to duplicate the use of a sitz ball.
[0044] While the invention has been described in terms of its preferred embodiments, it is intended that numerous modifications may be made thereto without departing from the spirit and scope of the invention. It is intended that all such
[0045] Modifications fall with the scope of the appended claims.
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A seat backing formed by a closed hollow plastic jacket defining a chamber fillable with a fluid and a valve, provided in the jacket, serving for feeding the fluid to the chamber. The invention includes a bearing region for holding a seat; a sitting region for receiving a sitting person; and a transition region formed between the bearing and sitting regions. The sitting region includes an upper sitting region and a lower sitting region. The transition region includes upper and lower sections formed around the sitting region and the bearing region to be integrally interconnect the bearing region and the sitting region. The area of sitting and bearing regions increases when the seat backing is used.
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BACKGROUND OF THE INVENTION
This invention relates to electronic circuits for determining the position of a rotating shaft and more particularly to such circuits which are suitable for use in aircraft power generating systems wherein the rotating shaft is the shaft of a dynamoelectric machine which is capable of operating as a generator or a motor.
In airborne electrical power generation systems, it is desirable to have a single system which provides both the starter and generator functions. The weight savings on an airplane can be substantial when a dedicated starter is eliminated. For this reasin, electrical power systems which are capable of providing engine start functions can provide both cost and weight savings.
Variable speed constant frequency (VSCF) power generation systems are commonly used for aircraft applications. One type of VSCF system includes a variable speed generator which supplies DC power to a pair of DC link conductors. An inverter circuit receives DC power from the link conductors and produces a constant frequency AC output. The inherent simplicity and reliability of DC link VSCF systems has been established and it is desired to modify the existing designs to provide starter capability.
DC link converters commonly utilize a transistor bridge output circuit having a pair of series connected transistors in each output phase leg adapted to be connected between the DC link conductors, wherein a connection point between the transistors serves as an output power pole. One method used to convert such a DC link VSCF system to a starter/generator system includes the use of a contactor or set of contactors to turn the system around so that an external electrical power source supplies the inverter input power and the generator is connected to the inverter as a load. In order to drive the generator as a synchronous motor, the absolute position of the rotor shaft must be known so that the inverter output transistors can be switched at the appropriate times to provide the desired motor action.
Since aircraft generators operate at 20,000 rpm at 225° C. with oil spray cooling, a rugged and reliable shaft position sensor is required. Common shaft position determining components such as resolvers, optical encoders, brush encoders and potentiometers will not survive in the harsh generator environment. A magnetic sensor/gear combination can provide a highly reliable position signal in such adverse environments. However, such systems provide relatively low resolution, do not provide relevant data at zero speed and do not known absolute position initially. It is therefore desirable to construct an absolute shaft position sensing circuit which includes a magnetic sensor/gear combination which overcomes these disadvantages.
SUMMARY OF THE INVENTION
A shaft position sensing circuit constructed in accordance with this invention includes means for generating a first pulse train having a plurality of regularly spaced pulses occurring at a frequency which is representative of the speed of rotation of an associated shaft. Means for generating a second pulse train is also provided wherein the second pulse train has a plurality of regularly spaced pulses and at least one irregularly spaced pulse which occurs once for each rotation of the shaft. A phase locked loop which includes a voltage controlled oscillator is connected to produce a first signal having a frequency which is representative of but greater than the frequency of pulses in the first pulse train. A counter receives this signal and produces an output count which is representative of the relative angular position of the shaft. Means is provided for detecting the occurrence of the irregularly spaced pulse in the second pulse train and for resetting the counter in response to the occurrence of this irregularly spaced pulse, thereby making the output count representative of the absolute angular position of the shaft.
The preferred embodiment uses a magnetic sensor/gear combination to produce the first and second pulse trains. The position sensor works on the principal of variable reluctance. The sensor produces a magnetic field adjacent to the ferromagnetic gear such that as an edge of each gear tooth approaches, the reluctance of the field path changes and a voltage spike is produced. Opposite polarity voltages occur for opposite edges of the gear tooth. By making at least one of the gear teeth wider than the others, the irregularly spaced pulse occurs when one of the edges of the wider tooth passes the magnetic sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a starter/generator system which includes the position sensing circuit of the present invention;
FIG. 2 is a block diagram of a position sensing circuit constructed in accordance with one embodiment of the present invention;
FIG. 3 is a schematic representation of a toothed wheel/sensor assembly used to provide the pulse trains required by the circuit of the present invention;
FIG. 4 is a schematic representation of the pulses produced by the wheel/sensor assembly of FIG. 3;
FIG. 5 is a schematic diagram of the magnetic sensor signal conditioning circuitry of the present invention; and
FIG. 6 is a schematic diagram of the absolute position sensing circuitry of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 is a schematic diagram of an aircraft electrical generating system which has been configured to provide a starting function. An inverter 10 that normally receives DC power on a pair of DC link conductors 12 and 14 from a dynamoelectric machine 16 which is operated as a generator and receives power from an associated aircraft engine, has been switched around to supply power to the dynamoelectric machine 16 thereby operating it as a starter motor for the associated aircraft engine. For this mode of operation, some other electrical power source, not shown, such as another power generating system or a ground power source is connected to supply power to DC link conductors 12 and 14. A three-phase sine wave reference generator 18 is connected to a reference voltage 20 and receives rotor position data on data bus 22 to produce a plurality of inverter switching waveforms on lines 24, 26 and 28. In order to obtain maximum torque, stator current is controlled with respect to the shaft position information. Current sensors 30 and 32 provide current feedback signals which are used to modify the switching pattern waveforms on lines 24, 26 and 28 by way of summing junctions 34, 36, 38 and 40.
An analog-to-digital converter 42 is connected to a reference voltage source 44 to provide a signal on data bus 46 which is representative of a fixed angle which is added to the rotor position. This fixed angle is added by way of adder 48 to a signal on data bus 50 which represents the absolute position of the rotor shaft. The present invention particularly relates to the position sensor circuit 52 as used in combination with a magnetic sensing device 54 and a wheel 56 connected to rotate with shaft 58 of the dynamoelectric machine 16. The wheel includes a plurality of peripheral teeth 60 with at least one of the teeth 62 being configured to produce an irregularly spaced pulse on the input lines 64 and 66 of the position sensor circuit as that tooth passes the magnetic sensor 54. The position sensor circuit 52 also provides a speed indicating signal on line 68 which is fed to a comparator 70 to provide a trip function for the inverter if the speed of the dynamoelectric machine becomes excessive.
FIG. 2 illustrates a block diagram of a portion of the position sensor circuit 52 in FIG. 1. In this drawing, and in FIG. 6, the heavy dark lines represent multiple conductor data buses. The magnetic sensor used in this preferred embodiment is shown to include a permanent magnet 71 which is connected to a ferromagnetic shaft 72 that is positioned adjacent to the teeth of the toothed wheel 56. A pick-up coil 74 is responsive to changes in the reluctance of the associated magnetic circuit to produce voltage pulses as the edges of the teeth pass the shaft 72. The leading edges of the teeth produce a first pulse train, containing regularly spaced pulses of a first polarity. The trailing edges of the teeth produce a second pulse train. Since at least one of the teeth 62 is wider than the others, the trailing edge of that tooth produces an irregularly spaced pulse which may be referred to as a misplaced pulse. A pre-amp and clamp circuit 76 receives the first and second pulse trains and produces a first output signal V REG on line 78 which is representative of the pulses of the first pulse train and a second voltage signal V IRREG on line 80 which is representative of the pulses of the second pulse train. A phase locked loop circuit 82 is responsive to the first voltage V REG and produces an output data signal which is representative of the rotor angle θ R on data bus 84. During initial start up of the dynamoelectric machine, an external starting circuit 86 produces a simulated rotor position signal which is coupled to data bus 88 by way of a plurality of data select switches 90. A comparator 92 which is connected to receive an external speed reference signal on terminal 94 and an indication of the actual rotor speed on line 68 from the phase locked loop circuit, controls the data select switches 90 so that once a preselected speed has been achieved, data bus 84 is connected to data bus 88 and the starting circuit 86 is disconnected. A position select circuit, shown in FIG. 6, is used to provide preset data by way of data line 96 to the phase locked loop circuit. A plurality of switches 98, only one of which is shown, also connect this preset data to a digital comparator 100. When both the V IRREG signal on line 80 and the digital comparator output on line 102 are at a logic high level, NAND gate 104 provides a reset signal by way of line 106 to the phase locked loop circuit 82. The operation of this circuit is described in greater detail with respect to FIGS. 5 and 6.
FIG. 3 is a schematic representation of the ferromagnetic toothed wheel 56 and the adjacent sensor shaft 72. Each of the teeth on the periphery of the wheel is shown to include a first edge 108. These first edges are regularly spaced around the periphery of the wheel such that as they pass sensor shaft 72, for a given speed, they produce a first pulse train which includes a plurality of regularly spaced pulses at a first polarity. Each of these teeth also includes a second edge 110 or 112. The majority of the second edges 110 are also regularly spaced around the wheel periphery. However, at least one of the second edges 112 is irregularly spaced. The wider tooth 62 is thereby used as a keying tooth for determining the absolute position of the associated rotor shaft. The irregularly spaced second edge 112 of the keying tooth 62 causes a misplaced pulse which is irregularly spaced with respect to the pulses produced by the second edges of the other wheel teeth. The operation of the toothed wheel/sensor is illustrated in FIG. 4. As the toothed wheel passes the sensor shaft 72, the first or leading edges of each tooth produce a first pulse train having a plurality of negatively going pulses 114 which are regularly spaced. Similarly, the trailing edge of each tooth produces a pulse train having a plurality of positively going, regularly spaced pulses 116 and one misplaced pulse 118 which corresponds to the trailing edge 112 of the wider tooth 62.
FIG. 5 is a schematic diagram of the magnetic sensor signal conditioner and phase locked loop which have been constructed in accordance with one embodiment of the present invention. The pulse trains produced by the sensing coil 74 include pulses having a magnitude which increases with speed. Therefore, these pulses are fed to a clamp circuit 120 which limits the voltage magnitude of the pulses delivered to a pre-amp circuit 122. The output of the pre-amp on line 124 is fed to a first comparator 126 which produces a voltage V REG on line 78. The pre-amp output is also fed by way of terminal 128 to a second comparator 130 illustrated in FIG. 6. The V REG signal is fed to a phase lock loop circuit which comprises a phase lock loop 132, a filter 134 and a voltage controlled oscillator 136. The voltage controlled oscillator frequency is 16 times the phase lock loop input frequency. The voltage controlled oscillator output is fed by way of line 138 to an 8-bit counter 140 which includes two counting circuits U4 and U5. By using a voltage controlled oscillator which has an output frequency that is larger than the input frequency to the phase locked loop circuit, the resolution of the position sensing scheme is improved. Within counter 140, the four most significant bit counter U5 output represents the position of each tooth on the toothed wheel. The four least significant bit counter U4 output defines the position of the toothed wheel between each tooth.
FIG. 6 shows that a plurality of switches 98 are used in an absolute position select circuit 142 to produce the required reset data on data bus 96. A keyed position select circuit 144 uses a plurality of switches 146 to produce a reference set of bits which represent the position of the keying pulse. These keying pulse bits are compared to the four least significant bits from position counter U4 by digital comparator U11. Comparator circuit 130 produces an output signal on line 102 which is representative of the second pulse train such that when the irregularly spaced pulse occurs, a signal from the output of NAND gate 104 on terminal 106 resets counter U5 in FIG. 5 with data from bus 96 which represents the true position of the keying tooth. Therefore, the output of counter circuit 140 is then representative of the absolute position of the shaft being measured.
In order to provide a more detailed illustration of the preferred embodiment, Table I includes a list of components used to construct the circuits of FIGS. 5 and 6.
TABLE I______________________________________Components in FIGS. 5 and 6Component Type/Value______________________________________U1 CA3140AU2, U12 LM311U3 4046U4, U5 74163U6 4050U7, U14 7407U8 HI-281U9 CA3140U10 VFC62U11 7405U13 4011C1 12 pFC2, C7 100 pFC3 50 pFC4 0.22 μFC5 300 pFC6 .001 μFCR1, CR2 IN985R1, R2, R9, R13, R31 100KΩR3, R4, R17 200KΩR5, R16, R28 15KΩR6, R7, R29 1.5KΩR8, R19-R25, R30 2KΩR10 10KΩR11, R27 5.1KΩR12 2.4KΩR14 5KΩR15 510ΩR18 39KΩ______________________________________
The present invention uses a gear/magnetic sensor in a simple absolute shaft position sensing circuit which can be used in high speed, high temperature, high vibration and oily environments. Interface circuitry is used to condition the sensor output and to determine the absolute shaft position. A phase locked loop provides resolution beyond that of the gear teeth. Although the present invention has been shown in terms of what is at present believed to be its preferred embodiment, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention. It is therefore intended that the appended claims cover such changes.
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An absolute shaft position sensing circuit uses a magnetic sensor and a toothed wheel to produce two pulse trains which are used to determine the absolute position of a shaft which is coupled to the toothed wheel. One pulse train includes regularly spaced pulses which are fed to a phase locked loop to produce an oscillating output signal. A counter counts this signal and produces an output count which is representative of the relative angular position of the shaft. A second pulse train includes an irregularly spaced pulse. Circuitry is provided to detect the occurrence of this irregularly spaced pulse and to reset the counter in response to that occurrence, thereby making the count representative of the absolute angular position of the shaft.
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FIELD OF THE INVENTION
This present invention relates very generally to surgical devices and more specifically to diagnostic or testing means for collecting liquid within a living body.
BACKGROUND OF THE INVENTION
Biological fluids contained in the extracellular spaces of living tissue, such as in the brain, other organs or subdermal tissue, often must be sampled for research or diagnostic purposes. If ample fluid is available, it may be simply withdrawn and analyzed directly. However, in many instances, only small amounts of fluid are available and sampling must be by indirect methods.
In vivo microdialysis sampling, during which little or no fluid is removed from or introduced into the system, involves implanting a short tubular dialysis membrane at the site of interest then continuously perfusing the interior of the membrane with a solution similar in composition to the body fluid at that site. The dialysate containing chemicals which diffuse through the membrane may easily be collected and analyzed.
For a decade, the use of microdialysis sampling in basic and pharmacokinetics research has proven to have many benefits such as clean samples, more frequent samples, conservation of body fluid, and fewer animals per study. In addition, it provides a direct profile of pharmacokinetics within the tissue of interest instead of traditional methods which calculate the tissue concentration indirectly from serial blood samples. Microdialysis sampling was originally developed for central nervous system ("CNS") studies but during the past several years its suitability for sampling from other sites has been demonstrated.
Various designs of microdialysis probes have been developed for particular sites or types of tissue. For example, the rigid cannula probe (such as the type disclosed in U.S. Pat. No. 4,694,832 by Ungerstedt, for example) is most suitable for sampling from the brain but has also been used to sample from adipose tissue, muscle and liver. It has long been known that such rigid probes often cause tissue damage during insertion and/or use. A flexible cannula probe (such as the type disclosed in U.S. Pat. No. 4,340,615 by Goodwin et at.) has proven more appropriate for sampling from blood, but has also been used in liver. Even though they may have various end geometries, both rigid and flexible cannula probes must have a relatively large overall diameter to accommodate their inlet and outlet tubing since they enter and exit a body at one point. That is, the in and out flowpaths are either looped, side-by-side or concentric as shown in U.S. Pat. No. 5,191,900 by Mishra. Linear design probes (which enter a body at one point, thread through the tissue of interest, and then exit the body at a second point) have been used for pharmacokinetics and metabolism studies of dermal tissue, muscle and tumor, and liver. The linear design has the advantages of minimizing tissue damage (because of its small diameter), being totally flexible (and therefore more comfortable), and usually sufficiently durable for use in awake, freely moving animals. A flow-through or shunt probe has also been designed for use in, for example, the bile duct. However, there are several problems or disadvantages with these prior art devices.
Other dialysis probes or similarly operating sampling devices are disclosed in U.S. Pat. No. 4,274,417 by Delpy; U.S. Pat. No. 3,830,106 by Gardiner et at.; and U.S. Pat. No. 3,128,769 by Scislowicz.
The aforementioned patents are only representative of the art in this area. Nevertheless, despite the large variety of designs and geometries available for sampling probes, there are still problems and a need for improvements in this art. For example, with most such probes, some other device (e.g. a guide cannula, a tunneling needle, or scalpel cut) is required to create a hole or passage into which the probe is placed. Since this hole must be somewhat larger than the outer diameter of the probe, it often causes much tissue damage. In addition, the short length of dialysis membrane required by the prior art designs reduces or slows the amount of sample recovered and makes analysis difficult and/or places constraints on the analytical methodology.
It is therefore an object of the present invention to provide a much smaller and completely flexible dialysis probe and a reliable method of implanting it which would minimize tissue damage to little more than the diameter of the probe itself.
A concern which arises in a probe having a small outer diameter, and hence a small inner diameter, is the recovery characteristics of the probe. Due to the small inner diameter, the velocity of perfusion fluid within the probe at a given volume flow rate is necessarily higher than that of a larger inner diameter probe, thereby reducing the percent relative recovery of the targeted analyte. It is therefore desired to provide a small inner diameter probe which provides the user with some control over the percent relative recovery.
SUMMARY OF THE INVENTION
The present invention aims to overcome some of the disadvantages of the prior art as well as offer certain other advantages by disclosing an improved linear microdialysis probe assembly consisting of a long length of plastic tubing having a short, thin semipermeable membrane window intermediate its ends. The tubing contains a length of strong but flexible, inert reinforcement or support fiber, preferably extending throughout its entire length, but at least extending through the membrane window and out beyond one end of the tubing. The support fiber is attached or bonded to the one end of the tubing to help resist longitudinal stress, thus allowing the probe to have an even smaller cross sectional profile but providing additional strength and flexibility compared to the prior art probes.
The invention also contemplates a method of inserting the new probe in a live animal to sample the interstitial fluid of a variety of soft tissues including dermis, muscle, adipose and subcutaneous tissue, liver and tumors by pulling one end of the fiber, and thus the attached probe, through the tissue with a needle until the membrane window is positioned where desired. The internal support fiber is handled like a suture thread and prevents fracture or over-straining of the thin and fragile membrane during pulling. This method minimizes the tissue damage which would otherwise result from the more common use of an insertion cannula larger than the outer diameter of the new probe. After both ends of the probe are pulled outside the body and secured, the sealed, fiber end is cut off, leaving the fiber inside the probe, and the tubing open. Long lengths of highly flexible plastic tubing may then be connected to the basic probe to convey fluids from the perfusion pump and to the analyzing equipment.
It is possible to implant the membrane portion of the probe in tissues that are quite distant from the exit site for the inlet and outlet tubing. This feature also makes the probe inherently more comfortable for the animal than a probe that must be anchored to skin proximal to the implant site. This new linear probe moves with the tissue and does not jab or tear tissue during normal respiration, digestion, or movement by the animal. As discussed below, this probe was implanted in the thigh muscle of an active flee-moving rat as a test of its ruggedness and stability. Such tests of this probe remained functional for up to six days.
BRIEF DESCRIPTION OF THE DRAWING
While this specification concludes with claims particularly pointing out and the subject matter which is now regarded as the invention, it is believed that the broader aspects of the invention, as well as several of the features and advantages thereof, may be better understood by reference to the following detailed description of a presently preferred embodiment of the invention when taken in connection with the accompanying drawing in which the FIGURE is an illustration of a linear probe for microdialysis constructed according to the teachings of the present invention and showing enlarged views of the membrane window and the insertion end portion of the probe assembly.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and particularly to the FIGURE, there is shown a preferred embodiment of the present invention in which the probe assembly (10) consists of a short, thin, tubular semi-permeable membrane (15) connected to a length of plastic inlet tubing (11) at one end and to a similar length of outlet tubing (18) at the other end so as to form a window in the probe intermediate its ends. Suitable semipermeable membrane materials are well known in the art and include polyacrylonitrile, cuprophan, regenerated cellulose, polycarbonate, polysulfone and the like. Since the membrane (15) is relatively weak and fragile compared to the plastic tubing (11, 18), a reinforcement or support fiber (12) extends through the membrane (15) and out the inlet tubing (11) where an end plug or seal (13) secures it as part of the probe assembly (10). Suitable support fiber materials include stainless steel, polymethyl methacrylate, polybutylene terephthalate, glass and similar biocompatible monofilaments.
During use, the probe (10) is surgically inserted, usually by pulling with a large needle (hence the need for strength), into a live animal (or person) where the extracellular biological fluid within the tissue of interest may be sampled through the semi-permeable membrane (15). The seal (13) prevents contamination of the inside of the probe tubing (11, 18) by body fluids during surgical insertion as well as providing the anchor point for the support fiber (12). To sample such biological fluid, a perfusion solution (i.e. an inert carrier such as saline solution) is pumped (by any common pump means such as a syringe, not shown) through the inside of the inlet tubing (11) to the membrane (15) where various low molecular weight chemical compounds in the tissue fluid adjacent the outside of the probe migrate across or diffuse through the membrane (15) into the solution to form an analyte which continues to flow via the outlet tubing (18) until it exits the probe (10). This probe effluent, containing the chemical compounds of interest carded in the perfusion solution, can then be analyzed by any of the well known methods, such as immuno-assay, chromatography or electrophoresis. One suitable electrophoresis system and method of using it with a microdialysis probe is disclosed in U.S. Pat. No. 5,449,064 which is incorporated herein by reference. Practical uses of the present invention are discussed in more detail below.
Pharmacokinetics Experiments:
Male Sprague-Dawley rats weighing 450-480 grams each were anesthetized intramuscularly using ketamine and xylazine (80 mg/kg and 10 mg/kg, respectively). An incision was made in the skin to expose the thigh muscle. A linear probe (10) was constructed according to the present invention with a cross section of about 180 μm and an overall length of about 51 cm. It was implanted in the muscle tissue of the thigh by inserting a 25 gauge needle through the muscle and inserting one end of the probe inlet tubing (11) through the needle's eye. The needle was then withdrawn and the probe (10) pulled through the tissue, placing the 10 mm length of dialysis membrane (15) fully inside the muscle. The internal support fiber (12) prevented fracture or over-straining the fragile membrane (15) during pulling. Once the probe (10) is implanted, the user has the option of removing the support fiber (12) to increase the flow area within the probe (10) and thus decrease the flow rate at the same pump settings which, in turn, increases the percent relative recovery. Such removal of the support fiber (12) requires detachment of the support fiber (12) from the inlet tubing (11) and removal of the support fiber (12) from within the membrane (15) or from within both the membrane (15) and the tubing (11, 18) by pulling the support fiber (12) at its end proximate the seal (13). Retention or reinsertion of the support fiber (12) into the tubing (11, 18) so that the support fiber (12) once again resides within the membrane (15) results in a decrease in the percent relative recovery of the probe (10) under constant pump flow rate conditions by decreasing the flow area within the probe (10), and, more specifically, by decreasing the flow area of the membrane (15), which increases flow velocity inside the membrane (15).
A length of PE 50 plastic tubing was cannulated into the femoral vein of the other leg for administration of drugs. The probe tubing (11, 18) and the cannula were tunneled under the skin and externalized at the center of the back of the neck. Following this surgical procedure, the rat was maintained in an awake animal system, which allowed movement without tangling of fluid lines. The rat had free access to food and water throughout the experiment.
An in vitro probe calibration procedure was used to relate percent recovery to percent delivery. Recovery was determined by using Ringer's solution spiked with a known concentration of acetaminophen. Delivery was determined by perfusing the probe (10) with a solution having a known concentration of acetaminophen and then monitoring the decrease in concentration in the probe effluent. Recovery and delivery in vitro were conducted in stirred solutions maintained at 37° C. At the beginning of each experiment, the probe was perfused for 30 minutes prior to collecting five dialysate samples at 10 minute intervals. In vitro recovery and delivery were then calculated as follows:
Recovery %=C.sub.d /C.sub.i ×100%
Delivery %=1-C.sub.d /C.sub.i ×100%
where C d is the concentration of a given compound in the dialysate and C i is the concentration of the same compound in the initial standard solution. Since recovery and delivery are derived values, the standard deviations were calculated by propagation of errors. An in vivo delivery calibration procedure was performed in a similar manner as the in vitro experiment, except that the probe was implanted in the muscle as described above. The initial delivery experiment began 3 to 4 hours after surgery (day 0) and was repeated daily.
On days 1 and 5, pharmacokinetics experiments were performed by perfusing the implanted probe with Ringer's solution at 2 μL/min. Samples were continuously collected over 10 minute intervals. Two blank samples were collected prior to dosing and no interferences were observed in these samples. A dose of acetaminophen (25 mg/kg) in 1 mL saline solution was administered into the femoral vein. Dialysate samples were collected for 4 hours after dosing at 10 minute intervals. Concentrations of acetaminophen were calculated by determining the dialysate concentration from a standard curve and corrected by using the in vivo delivery calibration data for the dialysis probe. Data acquisition and Pharmacokinetics Analysis (PKA) software from the assignee of this invention was used to convert the original chromatographic dam (obtained from a BAS 200 liquid chromatograph with internal UV detector settings of 250 nm) to concentrations and then plot and fit the pharmacokinetics data curves.
TABLE 1__________________________________________________________________________Probe Recovery Delivery Day Day Day Day Day DayNo. % % 0 1 2 3 4 5__________________________________________________________________________1 33.9 ± 0.1 48 ± 1 34 ± 1 24.7 ± 0.5 26 ± 42 43 ± 2 47.2 ± 0.2 43.6 ± 0.3 31 ± 1 29 ± 2 31.7 ± 0.53 63 ± 2 66.8 ± 0.5 30 ± 3 46 ± 2 37 ± 1 30.5 ± 0.2 27 ± 3 27 ± 64 63.1 ± 0.2 60.5 ± 0.3in: vitro vitro vivo vivo vivo vivo vivo vivo__________________________________________________________________________
In vitro recoveries and deliveries are shown in the left hand columns of Table 1. None of the probes showed a significant difference between recovery and delivery in vitro. Theoretically, in a stirred solution around the probe at constant temperature and perfusion flow rate, recovery and delivery of a given compound should be the same. Our results supported this theory and are in agreement with previously reported findings. We used the agreement of recovery and delivery in Vitro as an initial evaluation of the reliability of the probe. Table 1 also includes, in the right hand columns, the daily averages for delivery in vivo. These were lower than in vitro deliveries for the same probe. That in vivo delivery is different from in vitro delivery is not unexpected, since it is well known that in vivo recovery and delivery depends mainly on the properties of the medium surrounding the probe. Several approaches have been used to determine in vivo recovery. In vivo delivery of the analyte of interest has also been validated as a means of determining in vivo recovery in muscle. Using in vivo delivery to correct the dialysate concentrations is more accurate than using in vitro recovery. Our results showed that in vivo deliveries changed from day to day in the same animal. Therefore, the daily in vivo delivery value appears to be a better parameter for calculating the actual concentration of analyte in the tissue interstitial fluid. No interferences were observed in the samples obtained prior to dosing. Typical concentration-time profiles of acetaminophen in the muscle of another rat on days 1 and 5 showed that the t 1/2 of the absorption phase was 16 minutes for day 1 and 29 minutes for day 5 of the experiment. The t 1/2 of the elimination phase was 37 minutes for day 1 and 46 minutes for day 5 of that experiment. The peak concentration of acetaminophen in muscle dialysate was about 25 μM on day 1 and about 19 μM on day 5. The difference between in vivo delivery on days 1 and 5 of these experiments might be due to a change in circulation or diffusion in the tissue surrounding the probe under different circumstances (time of recovery after surgery, activity of the animal, or similar considerations). Other researchers have shown that acute inflammatory response of the tissue to the implantation and indwelling of the probe can affect its behavior.
The foregoing experiments illustrate the utility of microdialysis sampling in peripheral tissues for studying the disposition of a drug in vivo. In particular the reliability and durability of the new linear probe were demonstrated. While absolute calibration of the microdialysis probe is very difficult in tissue, normalization procedures can be used for experiment-to-experiment and time-to-time comparisons.
It will be appreciated by those of skill in the art that the probe of the present invention is smaller than those of the prior art while maintaining complete flexibility to enable the probe to be used without causing significant tissue damage during insertion and without causing damage to tissue when implanted within the animal. Thus, the animal is free to move after probe implantation.
It will also be appreciated that the probe of the present invention may be implanted in tissues that are distant from the exit sites for the inlet and outlet tubing. This feature is advantageous when compared to probes which must be anchored to skin proximate to the implant site. Greater flexibility is provided to the user for placement of the inlet and outlet tubing, and the probe may be implanted in a more comfortable position for the animal.
It will be further appreciated that the probe of the present invention provides a mechanism to allow the user to control the percent relative recovery of the targeted analyte. It is well known in the art that decreasing the flow rate of perfusion fluid within the probe thereby increases the percent relative recovery by reducing the concentration gradient between the perfusion fluid and the sample. Such control is not practicable in all instances, however, such as when using a perfusion pump already operating at a very low flow rate. The probe of the present invention provides the user with another method to increase percent relative recovery by removal of the reinforcement or support fiber (12). Keeping the flow at the perfusion pump constant, removal of support fiber (12) decreases the flow rate of perfusion within the probe and thereby increases the percent relative recovery of the targeted analyte. Re-insertion of the support fiber (12) into the probe results in a reduction in percent relative recovery of the targeted analyte and may be desired under certain circumstances. Use of a removably attached support fiber with the tubing of the probe may be used in conjunction with prior art probes, whether flexible or not, to provide control of the percent relative recovery of the probe.
While the present invention has been described in terms more or less specific to one preferred embodiment, it is expected that various alterations, modifications, or permutations thereof will be readily apparent to those skilled in the art. Therefore, it should be understood that the invention is not to be limited to the specific features shown or described, but it is intended that all equivalents be embraced within the spirit and scope of the invention as defined by the appended claims.
It will be appreciated that the use of an internal fiber attached to one end of the probe tubing provides protection for the interior of the probe during insertion into tissues, a tool for probe insertion which minimizes tissue damages, and a means of protecting the probe membrane against fracture or over-straining during insertion. Furthermore, the internal fiber supports the probe by resisting bending or crimping of the soft probe membrane while it is inside an active, moving animal so that flow can be maintained.
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An improved linear microdialysis probe assembly has a short semipermeable membrane portion containing a flexible, internal support or reinforcement fiber bonded to long lengths of inlet and outlet robing. Also disclosed is a method of using it to sample the interstitial fluid of a variety of soft tissues in a living animal including dermis, muscle, adipose and subcutaneous tissue, liver and tumors by pulling the fiber, and attached probe, through the tissue of interest with a needle until the membrane is positioned where desired.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
FIELD OF THE INVENTION
[0002] This invention relates to toy figures, specifically to toy figures used to project a simulated game aerial projectile.
BACKGROUND OF THE INVENTION
[0003] Various types of simulated games using an aerial projectile, popular with children and adults alike, are known in the art. The projectile is usually propelled by a simple catapult or a spring launcher, which sometimes replace a simulated ballplayer figure at the time of shooting the projectile toward a goal. Neither the launchers nor their substitution for a player figure at a critical point in the game simulate the reality very convincingly. While figures used in simulated games using a surface projectile often mimic the live action fairly well, figures devised for games using an aerial projectile, such as basketball, were so far much less successful.
[0004] Many simulated game inventions propose a catapult or a launcher: U.S. Pat. No. 5,788,242 (Rudell et al., 1998) shows a TWO SIDED BASKETBALL GAME with two simple launchers. U.S. Pat. No. 2,878,801 to Patchin et al. (1959) discloses a vertical TOY CATAPULT DEVICE with a horizontal support for rectangular projectiles. U.S. Pat. No. 2,203,990 to R. J. Haynur (1940) proposes a multiplayer GAME APPARATUS using a molded spring launcher and a projectile with parallel faces indicating a play board position for the next player. U.S. Pat. No. 1,612,699 to C. de V. Cole (1926) for a BASKET-BALL GAME has multiple player pieces, moving to random positions on the play board determined by a roll of dice, replaced for attempts at scoring by a catapult resembling an artillery piece. U.S. Pat. No. 731,850 to R. S. Bradbury (1903) discloses a GAME whereby a blade-spring launcher shoots a ball toward multiple baskets.
[0005] LEGO Sports started selling recently (2003) a type of a basketball player figure with a coil spring connecting its torso to its legs part, allowing the figure to ‘chest-slam’ a ball in a crude simulation of a throw. U.S. Pat. No. 6,171,169 to Saunders (2001) discloses an ARTICULATED TOY FIGURE SIMULATING BASKETBALL PLAY using a spring-loaded mechanism with a trigger and latch to swing an arm forward and downward, flinging a ball toward a basket. U.S. Pat. No. 2,911,758 to F. D. Carson uses a human figure shaped BALL CATAPULTING DEVICE with arms propelled by an elastic strip pulled crank to throw balls either upward from around its knees, or overhead backwards. U.S. Pat. No. 1,433,335 to K. Bensch (1922) discloses a BASKET-BALL TOY using figures with spring-loaded arms holding a cup, pulled by strings to shoot a ball. Probably the most realistically acting prior art figure is disclosed in U.S. Pat. No. 5,690,330 to Ozawa (1997.) It shows a TOY BASKETBALL GAME WITH SELF-JUMPING PLAYER ejected from a stationary base and releasing the ball on contact with the basket rim, simulating a so-called ‘slam dunk.’ None of the known figures simulates a player executing a jump shot or a hook shot, perhaps the most common shooting actions in basketball, handball and other games using an aerial projectile.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention provides an easy to manufacture and inexpensive toy figure simulating a jump shot, a hook shot and a ball pass for simulated games using an aerial projectile, such as basketball and others. Several objects and advantages of the present invention are to provide such toy figure, more particularly:
[0007] 1. to provide a toy figure throwing an aerial projectile using the energy supplied by resilient means in the form of a coil, leaf or other type of spring, or the energy of a resilient or elastic material forming a part of the figure or of its supporting base, said toy figure having either fixed or rotatable arms;
[0008] 2. to provide said toy figure that may be made or decorated to resemble real life ballplayers for marketing purposes, including player numbers on club color uniforms; and
[0009] 3. to provide a method of playing a simulated basketball game using at least one said toy figure, where the figures in a game may be either all of the same type or the various designs described in the present invention can be used for different game positions.
[0010] Further objects and advantages of the present invention will become apparent from a consideration of the ensuing description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings, closely related parts have the same number but different alphabetic suffixes.
[0012] [0012]FIG. 1 shows a toy figure energized by a leaf spring, where the leaf spring is substantially horizontal or inclined on a sharp angle from horizontal. The arms of the figure are shown as fixed.
[0013] [0013]FIG. 2 shows a similar figure with a substantially vertical leaf spring.
[0014] [0014]FIG. 3 shows another toy figure propelled by a coil spring, with forearms rotated forward by a string.
[0015] [0015]FIG. 4 shows a similar toy figure with arms rotated around their shoulder pins by a shaft.
[0016] [0016]FIG. 5 shows an ‘executive toy’ version with a ball shooting hand on a leaf spring.
[0017] [0017]FIG. 6 describes a version of a tabletop board for a simulated basketball game using the toy figures described in FIGS. 1 through 5.
[0018] [0018]FIG. 7 shows a version of dice used to randomly select the next game action.
REFERENCE NUMERALS IN DRAWINGS
[0019] [0019] REFERENCE NUMERALS IN DRAWINGS 10 Toy figure 11, 21, 31, 41, 51 Base 12, 22, 52 Leaf spring 13, 23, 33, 43 Body 14, 24, 44 Arms and Hands 15, 25, 35, 45, 55 Ball or Aerial projectile 16 Directional marks 36, 46 Arm pivot 32, 42 Coil spring 32a Coil spring - bent upper end 32b Coil spring - bent lower end 32c As 32b, pushed down 34 Forearm and hand 37 String 38 Arm elbow 39 Pin 40 Flange 47 Shaft 48 Link 49a Upper pin 49b Lower pin 54 Hand 61 Play board 62 Half-court markings 63 Full-court markings 64 Position indicia 65 Directional indicia 66 Toy figure of present invention 67 Basket, backboard and stand 68 Counterweight
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 —A Preferred Embodiment
[0020] [0020]FIG. 1 shows a preferred embodiment of my invention—a toy FIG. 10 simulating jump-shooting and ball passing in games using an aerial projectile. Said toy figure comprises a base 11 , resilient means in the form of a leaf spring 12 , and a body 13 in the shape of a ballplayer. Base 11 has a flat bottom surface large enough to provide stability. Spring 12 is attached toward one edge of base 11 and rising in a sharp angle to the horizontal plane over the center of said base, also for stability reasons. Body 13 is coupled to the opposite end of spring 12 . Arms and hands 14 of the figure are fixed in a typical raised jump-shooting position. A ball or other aerial projectile 15 is placed upon hands 14 formed to carry it. Base 11 and body 13 including arms and hands 14 are preferably cast of a plastic or metal material or a suitable equivalent, and attached to spring 12 by an appropriate glue, screws or other comparable method including casting directly around the spring. The spring 12 is formed of a substantially flat rectangular piece of a resilient plastic, metal or other material strong enough to withstand repeated flexing and to impart enough force to propel the ball 15 . The material, length, thickness and angle of the spring will affect the trajectory of the projectile, as will the weight of the projectile and other factors. Directional marks 16 may be placed on the base 11 or the spring 12 . Projectile 15 may be made to the requirements of any particular purpose.
Operation of a Preferred Embodiment
[0021] A user places said toy FIG. 10 on a play board over positional or directional indicia if provided. Directional marks 16 can be used to orient the figure toward a target. The user places ball 15 upon hands 14 and bends down spring 12 as indicated by phantom lines 12 a, estimating the force necessary to shoot ball 15 a desired distance. When spring 12 is released, it rebounds to its original position, carrying body 13 , hands 14 and ball 15 upward and forward on a curve. At the highest point of the curve the ball 15 is thrown in an arc indicated by the upper arrow.
Other Embodiments
[0022] [0022]FIG. 2 presents a similar toy figure with a substantially vertical leaf spring 22 carrying a body 23 and a ball 25 placed onto hands 24 . To shoot, a user bends spring 22 backward as indicated by phantom lines, while holding a base 21 . When spring 22 is released, a flatter shooting arc will be generated compared to a substantially horizontal spring. This type of toy figure may be positioned near a basket in a simulated basketball game, shooting ball 25 in a way resembling the action of a center or a forward. Arms and hands may be formed to simulate a hook shot, with one arm blocking opponents while the other arm throws ball in a high overhead arc.
[0023] [0023]FIG. 5 shows an ‘executive toy’ similar in function to FIG. 1. A hand 54 replaces the ballplayer shaped body 13 of FIG. 1. A base 51 , a leaf spring 52 and hand 54 can be all formed together of a clear, black or otherwise colored plastic material or metal, or made of a combination of materials. Spring 52 should be resilient enough to impart sufficient momentum to a ball 55 . A basket with a backboard and a stand formed from a similar material may also be provided. Instead of one hand 54 , a pair of hands may be used.
[0024] [0024]FIG. 3 shows a partially sectioned view of another type of the toy figure. A coil spring 32 is anchored by its bent upper end 32 a to a base 31 , and by its bent lower end 32 b to a body 33 . Each forearm and hand 34 is attached to the body at an arm pivot 36 . A string 37 , representing connecting means, is attached at one end to base 31 , goes through a cavity in body 33 around a pin 39 located in the shoulder area, and attaches to one forearm and hand 34 at an elbow 38 .
[0025] [0025]FIG. 4: the toy figure uses a coil spring arrangement 42 similar to FIG. 3. Arms and hands 44 rotate around an arm pivot 46 joining them through a hollow body 43 within shoulder area. A shaft 47 is attached to said arm pivot 46 by an upper pin 49 a and a link 48 . Shaft 47 is fixed rotatably to a base 41 by a lower pin 49 b. An optional flange 40 provides an easier hold while pushing down body 43 . Rack and pinion assembly could be also used to translate the vertical movement of the body into the rotation of the arms.
[0026] [0026]FIGS. 3 and 4 operate in a similar way (numbers for FIG. 4 are in parentheses): the user presses down body 33 ( 43 ) stretching coil spring 32 ( 42 ) while steadying base 31 ( 41 ,) using flange 40 if provided. After forearms and hands 34 (arms and hands 44 ) rotate to a lower position indicated by phantom lines, the user places a ball 35 ( 45 ) upon the hands. When body 33 ( 43 ) is released, spring 32 ( 42 ) pushes the body upward while string 37 (shaft 47 ) force forearms 34 (arms 44 ) to rotate forward. The combined motion pushes ball 35 ( 45 ) upward and forward in an arc indicated by the upper arrows. At the top of the arc the ball 35 ( 45 ) is thrown toward a goal. Both bodies 33 and 43 are preferably cast of a plastic or metal material or a suitable equivalent, with a cavity for connecting means. Rotatable arms or forearms including hands are preferably cast of the same material as the body, and attached to the body by said arm pivot 36 ( 46 ). Said coil spring 32 ( 42 ) is formed of a spring metal wire capable of providing enough force to throw the ball without being too difficult to stretch by an intended group of users. Shaft 47 , link 48 , pins 39 , 49 a and 49 b are preferably made of metal for strength and wear resistance.
[0027] [0027]FIG. 6 describes a version of a tabletop play board 61 for a simulated basketball game using the toy figures simulating a jump shot or a hook shot described in FIGS. 1 through 5. The board 61 can have either half-court game markings 62 and one basket, backboard and stand assembly 67 stabilized by a counterweight 68 , or full-court markings 63 partially indicated by dashed lines, with two basket, backboard and stand assemblies 67 on opposite ends of board 61 . The game can use one toy figure of present invention 66 or a plurality of them per team, using either one type of figure or different designs for different positions. For example, the toy figure of FIG. 1 could be used for both guard positions while toy figures shown in FIGS. 2, 3 or 4 would be placed in forward and center positions, one of them based on FIG. 2 simulating a hook shot. The toy figure(s) 66 are placed on position indicia 64 which may be replaced by directional indicia 65 as shown in positions numbered 4 , 5 (under the toy FIG. 66) and 6 on the board 61 . Directional indicia 65 pointing to the center of a basket should be supplemented by matching directional marks 16 as shown on the toy figure in FIG. 1. The positional and directional indicia could be variously combined on different sides of board 61 , for example to balance different skill levels of users. The game starts with a draw or a roll of standard dice to decide which user should start—the highest or the lowest roll starts the game as agreed by users. If only one toy FIG. 66 is used per side, the starting user puts it on the indicia 64 or 65 corresponding to the number on the dice. If 2 or more FIGS. 66 are used per side (5 as in the real game of basketball etc.,) the user passes a ball to the figure placed in the corresponding position before starting the game. Rolling number 6 on the dice could result in a foul shot from position number 6, or optionally in losing the turn to the next user. Users can take turns rolling the dice and shooting the ball, or can use the dice described in FIG. 7 to determine the action to be taken next. Score can be kept according to the usual basketball rules with one, two or three points per shot. A game ends in any way agreed on—a time limit, certain score reached etc.
[0028] [0028]FIG. 7 shows a variant of an action die for random determination of the next action to be taken by a user. If a user rolls P (Pass), the ball shall pass to a position optionally determined by a roll of a standard die indicating positions 1 through 6 . User that rolls S (Shoot) may attempt shooting at the goal from the position in possession of the ball. Rolling T (Turn-over) means the loss of the ball to the next user. The 3S-2P-1T probabilities indicated in FIG. 7 can be of course modified.
Conclusion, Ramifications, and Scope
[0029] Accordingly, the reader will see that the toy figures of the present invention simulate more realistically the jump shot or hook shot action of such aerial projectile games as simulated basketball and others. The toy figures are inexpensive to manufacture and can be shaped and decorated to resemble popular live ballplayers and their game uniforms, providing various marketing opportunities.
[0030] While the above description contains specific embodiments of the invention, these should not be construed as limitations on the scope of the invention. Many modifications obvious to those skilled in the art may be made without departing from the spirit of the invention. For example, the toy figure body can be oriented sideways with one arm formed to shoot a so-called hook shot, the leaf spring can be variously shaped to generate different ball trajectories, a rack and pinion assembly can be used as connecting means in place of string 37 or shaft 47 to rotate the arms, a spring type from one embodiment can be combined with an arm assembly from another, the body can be hand carved from exotic wood in any animate shape, such as an imaginary extraterrestrial being tossing a medium size galaxy and so on. Therefore, the scope of the invention should be determined by the appended claims and their legal equivalents.
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An easy to manufacture toy figure ( 10 ) simulating a jump shot or a hook shot for simulated games using aerial projectiles, plus a method to play a simulated game of basketball using said toy figure. A base ( 11 ) supports resilient means ( 12 ) which may be bent or compressed and then released to rebound substantially to their original form and position with speed sufficient to throw an aerial projectile ( 15 ) which was placed upon hands ( 14 ) of an animate body ( 13 ) attached to said resilient means. Said resilient means may be provided by a coil, leaf or other type of spring, or by a resilient or elastic material forming a part of the body or the base. Said animate body ( 13 ) may be designed to resemble popular ballplayers for marketing purposes, including player numbers on club color uniforms, with fixed or rotatable arms.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of producing a firm bond between a rigid subcomponent which comprises a polyamide containing thermoplastic composition and a flexible subcomponent comprising a vulcanized fluoroelastomer. The invention also relates to the articles obtained by this method.
2. Discussion of the Background
Composite materials comprising stiff thermoplastic molded materials and rubber-elastic molding materials are customarily joined together by adhesive bonding, screwing, mechanical interlocking or using a coupling agent. Recently, interesting methods of producing composites comprising a polyamide-based molding and a vulcanizate have been developed. Thus, EP-A-0 344 427 describes the production of a composite comprising polyamide and a rubber containing carboxyl or anhydride groups, while in EP-A-0 629 653 the rubber compound contains an unsaturated silane. The adhesive strengths achieved are notable but the method has some disadvantages. Thus, if the concentration of reactive groups in the rubber compound is relatively high, undesired adhesion to the metal mold customarily used in vulcanization can occur. In addition, for some applications it is extremely disadvantageous that the resistance of the elastomers used toward oils, fats, solvents and fuels, e.g. super-grade gasoline, diesel or alcohol-containing fuels is unsatisfactory, particularly at high temperatures.
Objects of the invention are therefore, starting out from the abovementioned prior art, as follows:
Use should be made of a commercial rubber which does not have to be additionally functionalized or modified and also requires no specific additions of reactive agents;
in the production process, the composite bodies should have no undesirable adhesion to the walls of the mold and should therefore be able to be removed from the mold without problems,
furthermore, the vulcanizate should be resistant to oils, fats, solvents and fuels over a wide temperature range,
finally, the adhesion at the phase interface of the composite should not be adversely affected by contact with oils, fats, solvents or fuels over a wide temperature range and over a long period of time.
SUMMARY OF THE INVENTION
These objects are achieved by a method of producing articles comprising at least two subcomponents which are firmly joined to one another which comprises i) a vulcanizate and ii) a polyamide containing thermoplastic wherein
said polyamide containing thermoplastic comprises at least 30% by weight of polyamide and in said polyamide at least 30% of the end groups are amino end groups;
comprising vulcanizing a fluororubber compound while in contact with said polyamide containing thermoplastic.
In a preferred embodiment, at least 50% and very preferably at least 70% of the end groups in the polyamide are amino end groups.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of the present invention, a polyamide containing thermoplastic composition contains a polyamide which is a high molecular weight compound which has --CO--NH-- linkages in the main chain. The polyamide containing thermoplastic composition comprises at least 30 wt. % of polyamide, preferably at least 40 wt. %, more preferably at least 50 wt. %, based on the weight of said polyamide containing thermoplastic composition. The polyamide containing thermoplastic composition may comprise 100 wt. % of polyamide, ≦90 wt. %, ≦80 wt. %, based on the weight of said polyamide containing thermoplastic composition. Polyamides are generally obtained from diamines and dicarboxylic acids or from aminocarboxylic acids by polycondensation or from lactams by polymerization. Possible polyamides are all those which can be melted by heating. The polyamides can also comprise further constituents which are built in by polycondensation, for example polyether glycols or polyether diamines. Examples of suitable polyamides are PA 46, PA 6, PA 66, PA 610, PA 612, PA 1012, PA 11, PA 12, PA 1212, PA 6.3-T and PEBA and also mixtures thereof. Such polyamides and preparation methods are conventionally known in the art.
The type and concentration of the end groups in the polyamide can be varied in a known manner by regulation of the molecular weight. If an excess of amino end groups is desired, regulation is advantageously carried out using a small amount of a diamine. This is a conventional practice for a person skilled in the art.
For the purposes of the present invention, a polyamide containing thermoplastic composition may be a polyamide molding composition which is a polyamide preparation which has been formulated for improving the processing properties or for modifying the use properties. Polyamide molding compositions may comprise, for example, stabilizers, lubricants, fillers such as carbon black, graphite, metal flakes, titanium dioxide or zinc sulfide, reinforcing materials such as glass, carbon, aramid or metal fibers, plasticizers, colorants, flame retardants, impact modifiers or a mixture thereof. The proportion of the reinforcing materials in the molding compositions can be up to 50% by weight, that of the flame retardants up to 20% by weight and that of all other additives together up to 10%, in each case based on the total molding composition.
For the purposes of the present invention, a polyamide containing thermoplastic composition may also be a polyamide blend which is a molding composition which is comprised of polyamides and other polymers and also the additives customary for the polyamide molding compositions. The polymer constituents can be soluble in one another or one polymer constituent can be dispersed in the other or the two can form interpenetrating networks. Preferred polyamide blends for the purposes of the present invention are mixtures of polyamides and polyphenylene ethers in which the polyphenylene ether is dispersed in the polyamide. Such molding compositions are produced by melting and mixing at least 30% by weight of a polyamide, preferably at least 40 wt. %, more preferably at least 50 wt. %, based on the total weight of the molding composition with from 0 to 70% by weight, preferably 10 to 60 wt. %, more preferably 20 to 50 wt. % of a polyphenylene ether. Molding compositions based on polyamides and polyphenylene ethers are described, for example, in DE-A 30 27 104 and also in EP-A-147 874 and EP-A-O 024 120. It is known to a person skilled in the art that these molding compositions customarily contain a compatibilizer.
Further suitable polyamides may be impact-modified polyamides, e.g. polyamides having a rubber dispersed therein.
A fiber composite material having a polyamide matrix may also be used for the purposes of the present invention, which comprises uncut reinforcing fibers or fabrics on the one hand and a matrix comprising a polyamide, a polyamide molding composition or a polyamide blend on the other hand.
Fiber composite materials having a matrix comprising polyamides, polyamide molding compositions or polyamide blends can be produced in various ways, for example polyamide-impregnated reinforcing fibers or reinforcing fabrics, known as prepregs, can be consolidated by pressure and heat to form laminated sheets. It is also possible to process hybrid yams of polyamide fibers and reinforcing fibers, or films of the thermoplastics mentioned and fabrics of reinforcing fibers under pressure and heat to form composite materials. Suitable reinforcing fibers are, for example, glass fibers, carbon fibers and aramid fibers.
The rubber compounds used according to the invention comprise a fluororubber (FPM) which can be prepared in a known manner. Suitable fluororubbers are described, for example, in K. Nagdi, Gummi-Werkstoffe, page 254 ff, Vogel-Verlag Wuerzburg 1981 and in The Vanderbilt Rubber Handbook, 13th Edition, pp. 211 ff, Vanderbilt Company Inc., Norwalk, Conn. 1990. Examples which may be mentioned are vinylidene fluoride-hexafluoropropene copolymers, vinylidene fluoride-hexafluoropropene-tetrafluoroethene terpolymers or vinylidene fluoride-tetrafluoropropene-perfluoro(methyl vinyl ether) terpolymers.
Suitable fluororubbers are produced, for example, by DuPont under the name Viton, by 3M under the trade name Fluorel, by Montefluos under the name Tecnoflon and by Daikin Kogyo Co., Japan under the name Dai-el. The selection of the type of rubber depends on the desired vulcanizate properties.
Apart from the rubber, the FPM mixtures can contain a limited number of additives such as fillers, color pigments, processing aids, lubricants or metal oxides as neutralizing agents for acids. They further comprise a vulcanizing agent.
Fillers which can be used are various carbon blacks and mineral fillers. As processing aid and plasticizer, it is possible to use, inter alia, liquid fluororubber. Suitable lubricants are, inter alia, carnauba wax and low molecular weight polyethylene. In general, metal oxides such as magnesium oxide are added to all FPM mixtures. These lead to a high degree of crosslinking and at the same time act as neutralizing agents for hydrogen fluoride which is formed during vulcanization.
Crosslinkers suitable for FPM mixtures are based, inter alia, on bisphenols and phosphonium compounds. These are often already present in the base polymer.
Types of FPM which do not contain a crosslinker are generally crosslinked using diamine compounds such as hexamethylenediamine carbonate or using organic peroxides in the presence of, for example, triallyl isocyanurate.
As regards suitable additives and crosslinkers, it is advisable to follow the advice of the FPM manufacturers, e.g. in the respective product brochures. The invention is not restricted to particular crosslinkers.
The articles comprising the polyamides, polyamide molding compositions or polyamide blends on the one hand and fluororubber compounds on the other hand can be produced in one or two stages. Articles comprising fiber composite materials and rubber compounds are produced in two stages.
In the two-stage process, the stiff molding is first produced by injection molding, extrusion or consolidation of prepregs and, in a second step, the possibly preshaped rubber compound is applied and the molding is exposed to the vulcanization conditions for the rubber. The application of the rubber to the stiff molding can be carried out by pressing, injection molding or extrusion.
In the two-stage injection molding process, the procedure is similar to that in the two-stage production of two-color injection moldings. The insert used is a molding made of the rigid materials mentioned. Barrel and screws of the injection molding machine are configured in a known way for rubber processing and the tool is treatable to the vulcanization temperature. If external mold release agents are used, care should be taken to ensure that they do not get into the interface between the materials since they can adversely affect adhesion in the composite.
For application of the rubber and vulcanization by the two-stage extrusion process, a profile produced in the first stage from a polyamide molding composition, e.g. a pipe, is, for example, sheathed with the rubber composition and vulcanized, if appropriate under pressure. Sheets comprising polyamide molding compositions or fiber composite materials having a polyamide matrix are processed correspondingly.
In the one-stage injection molding process, the procedure is analogous to the one-stage two-color injection molding process. In this case, one injection molding machine is equipped for thermoplastic processing, the other for rubber processing. The tool is heated to the prescribed vulcanization temperature which should be below the solidification temperature of the polyamide, the polyamide molding composition or the polyamide blend.
The optimum vulcanization conditions depend on the chosen rubber mixture, in particular its vulcanization system, and the shape of the molding. Thus, suitable temperatures in the tool are generally in the range from 140 to 210° C. If the softening range of the rigid component permits, temperatures in the upper part of this range, e.g. from 170 to 210° C., are selected. The vulcanization times depend on the rubber mixture and also on the vulcanization temperatures and the geometry of the parts. They are generally from 30 seconds to 30 minutes; lower temperatures and thicker rubber parts require longer times.
As a rough guide, the vulcanization is complete in from 2 to 15 minutes at temperatures of from 150° C. to 200° C.
The composites are generally, as is customary for fluoroelastomers, subsequently after-vulcanized; in the after-vulcanization, the prevulcanized parts are, for example, heated under atmospheric pressure in ovens with circulation of hot air and feeding-in of fresh air or nitrogen in order to complete the crosslinking reaction. Typical heating conditions are 24 hours at from 200 to 260° C.
The composite produced according to the invention is so strong that testing usually results in a cohesive fracture in the vulcanizate but not in separation at the phase interface.
The vulcanizates present in the composite bodies have excellent resistance to high temperatures, ozone, oxygen, mineral oils, fuels, aromatics and organic solvents.
Applications for the composites of the invention are, for example, rubber-coated rollers, flanges, pipe and hose couplings, sealing frames, seals, in particular shaft sealing rings, running rollers, clutch and brake disks, membranes and also coextruded pipes and hoses.
Experimental Part
1. The following polyamide molding compositions are used for the rigid component:
1.1. Commercial polyamide 612 containing 20% by weight of short glass fibers.
The ratio of amino end groups to carboxyl end groups is about 5:1.
1.2. Blend of 50 parts by weight of PA 66 and 10 parts by weight of PA 6.3-T together with 40 parts by weight of short glass fibers. PA 6.3-T is prepared by polycondensation of terephthalic acid or terephthalic acid derivatives and trimethyl-substituted hexamethylene diamine. The ratio of NH 2 to COOH groups in this blend is about 5:1.
1.3. Commercial PA 612 having a ratio of NH 2 to COOH groups of about 1:10 (not according to the invention).
1.4. Similar to 1.2.; but the ratio of NH 2 end groups to COOH end groups is here about 1:6 (not according to the invention).
2. Rubbers used:
2.1. Viton A
This is a fluororubber from DuPont de Nemours, Geneva, Switzerland. The properties of the product may be found in the product information "Viton Fluororubber".
2.2. Viton B 651 C
This is a fluororubber (terpolymer) from DuPont de Nemours, Geneva, Switzerland, with an integrated crosslinker based on aromatic dihydroxy compounds. The properties of the product may be found in the product information "Viton Fluororubber".
2.3. Dai-el G 763
This is a fluororubber from Daikin Kogyo Co., Japan, with an integrated crosslinker based on aromatic dihydroxy compounds. The properties of the product may be found in the corresponding product information.
3. Rubber compounds:
The rubbers used are mixed with additives; the composition of the compounds is shown in Table 1.
TABLE 1______________________________________Composition of the rubber mixturesExample 3.1 3.2 3.3 3.4______________________________________Rubber 2.1 100.0Rubber 2.2 100.0Rubber 2.3 100.0 100.0Maglite D 1) 3.0 3.0Maglite Y 2) 15.0 15.0Blance Fixe Micro 3) 15.8 10.0Carbon black N 990 4) 10.0 5.6 25Lunacerra C 44 5) 2.0 0.1 0.5Diak No. 1 6) 1.5Calcium hydroxide 6.0 6.0______________________________________ Explanations for Table 1: 1 ) Maglite D is a highactivity magnesium oxide from Merck & Co. Inc., Rahway, New Jersey. 2 ) Maglite Y is a lowactivity magnesium oxide from Merck & Co. Inc., Rahway, New Jersey. 3 ) Blance Fixe Micro is a barium sulfate as supplied by various manufacturers. 4 ) Carbon black N 990 is a lowactivity carbon black which is supplied by Degussa AG, Hanau. 5 ) Lunacerra C 44 is a paraffin wax (hard wax). 6 ) Diak No. 1 is a crosslinker based on hexamethylenediamine carbamate from DuPont de Nemours, Geneva.
To demonstrate the bonding action, test specimens are produced by, as specified in DIN 53531, part 1, producing a plastic plate from the thermoplastic, covering one third of this with a Teflon film, laying a matching rubber sheet onto the plate, producing the composite by the pressing method and finally sawing out test specimens having a width of 25 mm. A peeling test is then carried out. In this test, the rubber part which has been kept separated from the polyamide material by means of the Teflon film during vulcanization is fixed in such a way that in the peeling tests the rubber strip is pulled off perpendicular to the thermoplastic surface. The results are shown in Tables 2 and 3.
TABLE 2______________________________________Properties of the composite materials of the invention; peeling test inaccordance with DIN 53531/53539Ex- Vulcanization Separationam- Polyamide temperature in Vulcanization force inple Rubber material ° C. time in minutes N/mn______________________________________4.1 3.1 1.1 180 10 7.74.2 3.1 1.2 200 5 8.14.3 3.2 1.1 180 10 6.44.4 3.3 1.2 200 5 7.54.5 3.4 1.1 180 10 8.04.6 3.4 1.2 200 5 8.2______________________________________
In all tests, separation occurred in the vulcanizate layer (cohesive fracture) and not in the plastic/vulcanizate interface.
In contrast, for the two comparative molding compositions 1.3 and 1.4 satisfactory bonding strengths cannot be achieved, i.e. separation of the composite occurs in the plastic/vulcanizate interface without any great application of force, see Table 3.
TABLE 3______________________________________Composites not according to the invention; peeling testin accordance with DIN 53531/53539Ex- Vulcanization Separationam- Polyamide temperature in Vulcanization force inple Rubber material ° C. time in minutes N/mn______________________________________A 3.1 1.3 180 10 1.7B 3.1 1.4 200 5 1.1C 3.2 1.3 180 10 1.4______________________________________
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
This application is based on German patent application DE 197 18 504.5 filed in the German Patent Office on May 2, 1997, the entire contents of which are hereby incorporated by reference.
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Composite comprising a polyamide-based molding composition and vulcanized fluoroelastomers. Composite articles comprising at least two subcomponents which are firmly joined to one another which comprise i) a vulcanizate and ii) a polyamide containing thermoplastic wherein
a) said polyamide containing thermoplastic comprises at least 30% by weight of polyamide and in said polyamide at least 30% of the end groups are amino end groups and
b) said vulcanizate is produced by vulcanization of a fluororubber compound while in contact with said polyamide containing thermoplastic.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-345186, filed Nov. 9, 2001, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a signal processing method and apparatus for recording a digital signal in a recording medium or for transmitting to a transmission medium, a signal reproducing method and apparatus for reproducing the digital signal recorded in the recording medium or transmitted via the transmission medium, and further a recording medium in which the digital signal is recorded.
[0004] 2. Description of the Related Art
[0005] Recently, any type of information can be digitized and technology capable of distributing such information through transmission media or recording media has been developed, as expressed by the term “digital revolution.” As a result, a great number of people have come to acquire digital information freely. In such an environment, signals such as digital audio signals, digital video signals, relating data which computers handle are recorded in a recording medium. Information transmission and storage are carried out so that the above-described signals are reproduced from the recording medium, information is copied to a read-only medium, transmitted information is reproduced or information is transmitted through a transmission line.
[0006] Recently, as a recording medium capable of recording a large volume of video/audio information, the digital versatile disc (DVD) has been realized. A movie over two hours long is recorded in a DVD and such DVD recorded information is reproduced through a playback apparatus, so that the movie can be watched freely at home.
[0007] DVDs are classified into: read-only DVD-ROMs, DVD-Rs which allow a one-time recording, and DVD-RW, DVD-RAM which allow re-recording.
[0008] An application standard for DVD-ROM includes a DVD-video standard which allows a whole movie to be recorded in a single disc. A user can acquire information based on digital signals freely through reproduction of such DVD-video discs or reception of digital broadcasting. Under such circumstances, if the acquired digital signals are copied to a recording medium such as a hard disc and the aforementioned DVD-RAM and encoded with an encoder based on the DVD-video standard, it is possible to copy a disc.
[0009] Thus, in a DVD-video, digital information to be recorded is encrypted. The copy protect method employing cryptography technology functions effectively for a DVD-video disc or DVD-ROM, in which encrypted information is pre-recorded.
[0010] Examples of a conventional technique relating to encryption include a technique described in Jpn. Pat. Appln. KOKAI Publication No. 11-86436. In this technique, specific data different from main information data is mixed in an error correction code block. The specific data is used as copy inhibition information. Another example is a technique described in Jpn. Pat. Appln. KOKAI Publication No. 9-128890. In this technique, in order to prevent illegal copy of the digital signal, a part of an error correction code is replaced with specific data (such as an encryption key) and recorded. Further example is a technique described in Jpn. Pat. Appln. KOKAI Publication No. 8-204584. In this technique, in a case in which data subjected to an error correction processing is supplied to a decryption processing block, an uncorrectable data portion is changed to a special code including a synchronous code and transmitted so that the portion can be detected by a decryption processing section. An error portion is recognized by using the special code, and decryption is performed based on the error portion.
[0011] In a field in which the above-described information transmission/storage processing is performed, in recent years, it has further become important to handle copyright protection. Particularly when the information requiring the copyright protection is recorded in a conventional recording medium, illegal copy needs to be prevented from being performed. That is, although a copyright holder permits information recording only for one recording medium, the same information may be recorded in a plurality of recording media. The generation of this illegal action is considered, and it is absolutely necessary to prevent the illegal action. Moreover, there has been a demand for further reinforcement of the prevention of the illegal action.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention has been developed in consideration of the above-described circumstances, and an object thereof is to provide a signal processing method and apparatus, signal reproducing method and apparatus, and recording medium in which copy protection is reinforced.
[0013] According to an embodiment of the present invention, a signal processing method comprises:
[0014] multiplexing/arranging digital data of a specific unit to form a predetermined unit;
[0015] adding an error correction code to the predetermined unit to constitute an error correction coded block;
[0016] replacing a part of the error correction coded block with specific data; and
[0017] outputting the error correction coded block with the specific data being replaced to a transmission medium or a recording medium.
[0018] Additional objects and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.
[0019] The objects and advantages of the present invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0020] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present invention in which:
[0021] [0021]FIG. 1 is a block diagram showing a recording data processing process for use in a DVD system;
[0022] [0022]FIG. 2 is an explanatory view showing a constitution of a data sector for use in the DVD system;
[0023] [0023]FIG. 3 is an explanatory view showing the constitution of an assembly block of the data sector for use in the DVD system;
[0024] [0024]FIG. 4 is an explanatory view showing the constitution of an ECC block for use in the DVD system;
[0025] [0025]FIG. 5 is an explanatory view showing the constitution of the ECC block for use in the DVD system and after a row interleave processing;
[0026] [0026]FIG. 6 is an explanatory view showing the constitution of a recording sector for use in the DVD system;
[0027] [0027]FIG. 7 is an explanatory view showing the constitution of a physical sector for use in the DVD system;
[0028] [0028]FIG. 8 is a schematic view of a content scramble system (CSS) for a copyright protection system of a DVD-video signal for use in a read-only medium of DVD standards;
[0029] [0029]FIG. 9 is an explanatory view of the copyright protection system in the DVD system;
[0030] [0030]FIG. 10 is a schematic explanatory view of a DVD player;
[0031] [0031]FIG. 11 is an explanatory view of the copyright protection system in a recording/reproducing apparatus;
[0032] [0032]FIG. 12 is a whole explanatory view of the recording/reproducing apparatus;
[0033] [0033]FIG. 13 is a constitution explanatory view of a recording apparatus according to an embodiment of the present invention;
[0034] [0034]FIG. 14 is an explanatory view showing one example of an embedded place of specific data;
[0035] [0035]FIG. 15 is an explanatory view showing another example of an embedded place of specific data;
[0036] [0036]FIG. 16 is an explanatory view showing a still another example of an embedded place of specific data;
[0037] [0037]FIG. 17 is an explanatory view showing a further example of an embedded place of specific data;
[0038] [0038]FIG. 18 is an explanatory view showing a still further example of an embedded place of specific data;
[0039] [0039]FIG. 19 is a constitution explanatory view of a reproducing apparatus according to an embodiment of the present invention; and
[0040] [0040]FIG. 20 is a constitution explanatory view showing a processing process of specific data in a reproduction processing time.
DETAILED DESCRIPTION OF THE INVENTION
[0041] An embodiment of the present invention will now be described with reference to the accompanying drawings. A recording/reproducing processing method in/from an information recording medium, which requires an illegal copy prevention processing, will be described hereinafter from a viewpoint of copyright protection. Particularly, a signal processing method and reproducing method and apparatuses regarding data arrangement will be described hereinafter in a case in which concealment information is embedded in a data block.
[0042] [I] Background Studied for Realizing the Present Invention
[0043] The copyright protection system for use in an optical disc DVD which has remarkably spread in recent years will first be described hereinafter.
[0044] [0044]FIG. 1 shows signal processing in a recording medium in a copyright protecting system for a DVD-video signal. In data control processing, a video/audio information signal is compressed using MPEG, or the like, and further formatted to a digital data stream having a reproduction control signal or the like added thereto (step S 1 ).
[0045] Digital data is divided into sectors of packet data each having the unit of “2K bytes” (step S 2 ) and an ID which is a sector number is attached to each sector (step S 3 ). Next, data is encrypted (data scramble) (step S 4 ). An error detecting code EDC is attached to the encrypted data (step S 5 ). A data portion is scrambled according to a code determined by ID information so as to stabilize the servo system in reproduction operation (step S 6 ).
[0046] The data scramble here is different from the data scramble for the above-described encryption, so that data is scrambled with open contents. If digital data is “all 0” or in similar case, recording data turns to be repetition of same pattern. In this case, a disc system may have a problem in that a tracking servo error signal cannot be detected accurately, due to cross-talk of an adjacent track. The initial value of an M system generator is determined by an ID value. By multiplying a signal from the M system generator with digital data, data scramble is carried out. This prevents the scrambled recording signal from being a repetition of same pattern. In this specification, the “data scramble” used for servo stabilization will not be described any more but the “data scramble” described elsewhere in this specification indicates that used for encryption processing for protection of copyright of information.
[0047] The digital data subjected to the above-described processing is converted to blocks based on the error correction code ECC so as to execute error correction processing for every 16 sectors (step S 7 ), and error correction codes of an inner-code parity PI and an outer-code parity PO are generated (step S 8 ).
[0048] The outer-code parity PO is distributed in each sector by interleave processing so that a recording sector is constructed (step S 9 ). The recording sector data is modulated through a modulating circuit (step S 10 ) and the modulated signals are recorded by cutting an original disc through a driver and a pickup device. FIG. 1 shows the same structure as a marketed recording/reproducing apparatus whose pickup portion has a different power.
[0049] Based on the original disc, a disc manufacturing mold is produced through a disc manufacturing process and then, a large number of discs are copied using an injection machine and provided to the market as a DVD-ROM disc in which video signals are recorded.
[0050] [0050]FIG. 2 shows the structure of the data sector of FIG. 1.
[0051] The data sector is constituted of 172 bytes (=1 row)×12 rows and sector identification information ID comprised of a sector number and sector information is arranged at the head row, followed by an ID error detecting code IED, information concerning protection of copyright CPR_MAI, a 2-K byte main data area and finally an error detecting code EDC for main data.
[0052] [0052]FIG. 3 shows a constitution of ECC block. The ECC block comprises 16 data sectors of FIG. 1, and data of 172 bytes×192 rows (=(172 bytes×12 rows)×16 sectors)).
[0053] [0053]FIG. 4 shows the structure of the ECC block. In data of 172 bytes×192 rows constituted by gathering 16 of the data sectors in FIG. 3, the outer-code parities POs of 16 bytes (16 rows) are generated to each column (vertical direction) while the inner-code parities PIs of 10 bytes (10 columns) are generated to each row (lateral direction). Here, the outer-codes PO of 16 rows (16 bytes) are distributed such that a row (172 bytes) is interleaved for every 12 rows (each sector), as shown in FIG. 5.
[0054] [0054]FIG. 6 shows the structure of a sector picked out from respective sectors after the outer-codes POs are interleaved. This is called a recording sector. (12+1) rows are provided because a part (a single row) of the outer-code parities POs is added to the sector (12 rows) shown in FIG. 2.
[0055] [0055]FIG. 7 shows the structure of a physical sector generated by passing data stream of each recording sector through a modulator.
[0056] The modulator code-modulates each data symbol (1 byte=8 bits) to 16 channel bits.
[0057] As shown in FIG. 7, a pair of sync frames of (32+1456) channel bits constructs a single row. For example, at the first row of FIG. 7, SY 0 and SY 5 are sync frames. Gathering 13 of such row constructs the physical sector.
[0058] As described above, in the DVD system, the data sector of 2 Kbytes is a unit of processing, the ECC block is constituted by a unit of 16 sectors, and the error correction code is added to the block. With this data structure, it is possible to manage the data by a unit of 2 Kbytes. Moreover, since the error correction code is added to the ECC block by the unit of 16 sectors, an error correction capability is enhanced.
[0059] In such a DVD, protection on information is carried out for video signals to be recorded in a ROM disc specialized for reproduction as copyright protection system. In this case, a copy protection system called a content scramble system (CSS) is employed as the copyright protection system. However, the copy protection system is not a complete system. If the total data of a disc is backed up and restored, such a high level control as “check-in” processing cannot be carried out.
[0060] [0060]FIG. 8 is a schematic diagram of the copyright protection system CSS (Content Scramble System) of a DVD-video signal used for reproduction dedicated media of the DVD standard.
[0061] At the side of disc recording, the digital content is MPEG-encoded, and encrypted by the CSS system, and recorded on a read-only medium (steps A 1 , A 2 , A 3 and A 4 ). Reproduction processing for this medium, at a general DVD dedicated player (a consumer appliance), the encrypted contents are decrypted (step A 5 ), and the compressed data is expanded by an MPEG decoder or the like (step A 6 ), and it is reproduced as a video/audio signal.
[0062] In a reproduction processing in a computer environment of a personal computer or the like, the digital data from the above-described medium is reproduced by a DVD-ROM drive (step A 7 ). The read digital data is not transmitted as is on a PC bus, and firstly, MPEG decoder module and authentication mutual identification (bus authentication) are carried out (steps A 7 and A 8 ). Further, this is a system in which the encrypted contents are transferred to only a proper decoder module. In this case, the data is transferred from the DVD-ROM drive to the decoding section, and the encrypted contents are decrypted (step A 9 ). The compressed data is expanded by the MPEG decoder or the like (step A 10 ), and it is reproduced as the video/audio signal.
[0063] [0063]FIG. 10 is a schematic diagram of a content encoding method of the CSS.
[0064] Three encryption key data, namely, a master key which the CSS management mechanism holds, and a disc key and a title key which a copyright holder or the like determine, are hierarchically combined, and data of video and audio are encrypted by the encryption key.
[0065] In the example of FIG. 9, the disc key is encrypted by using the master key (block D 1 ), and it becomes a disc key block. The title key is encrypted by using the disc key by the encrypting section (block D 2 ), and it becomes an encrypted title key. A content such as image data, audio data, and the like from a content section (D 3 ) is compression-processed by a compression processing section (block D 4 ), and the compressed data is scrambled by a scrambling section (block D 5 ).
[0066] The master key is an encryption key data differing for each manufacturer of a decryption LSI or a software CSS module.
[0067] The CSS management mechanism collectively holds the master keys of a large number of manufacturers. When the disc key is encrypted, a disc key block which can basically be decrypted by any of the master keys is prepared, and the disc key block is stored on a disc. Thus, damage when information of a master key given to a manufacturer leaks can be kept to a minimum.
[0068] Concretely, from the next time of preparing a disc key block, a disc key block prepared with the leaked master key removed is prepared. Thereafter, decrypting by using the leaked master key cannot be carried out.
[0069] [0069]FIG. 10 is a schematic diagram of content decryption in the DVD player reproducing a disc on which the encrypted content prepared in FIG. 9 is recorded. The encrypted “disc key block” is read from the disc, and the disc key is decrypted by using the master key by a decrypting section (block E 1 ). The encrypted title key read from the disc in the same way is decrypted by the above-described decrypted disc key by a decrypting section E 2 . Further, scrambled “A/V data” which is the content is descrambling-processed by using the decrypted title key by a descrambling section E 3 . The descrambled content is reproduced as the video/audio signal by an A/V decoder (block E 4 ) such as an MPEG-2 decoder or the like.
[0070] The outline of the copyright protection system using the CSS method for a read-only medium has been described above. To perform the copyright protection, the content is encrypted by the scramble processing in this manner. Moreover, in the reproduction system, for the decryption of the encrypted content, the content cannot be decrypted until the encrypted key is decrypted. The copyright protection is thus performed.
[0071] In the read-only DVD system, since the recording side is processed in an edition operation by the reproduction of the master disc, the copyright protection is easily managed. However, in the DVD system in which the recording/reproducing is possible, a recording processing section exists in many apparatuses. Therefore, there is a possibility that an illegal apparatus capable of illegally copying the content is manufactured and a large number of content recording media are prepared by illegal copy.
[0072] The constitution of the copyright protection system in the recording/reproducing apparatus according to the present invention will next be described. This copyright protection system will be studied.
[0073] [0073]FIG. 11 shows the structure of the copyright protection system in a recording/reproduction device. A recording section comprises a random number generating device G 0 , A/V encoding section G 1 , scrambling section G 2 , an encrypting section G 3 , and disc key processing section G 4 . A reproduction section comprises decryption sections G 11 , G 12 , descramble section G 13 , and A/V decoder section G 14 .
[0074] The audio(A)/video(V) content is encrypted by scrambling processing by using a title key TK generated in the random number generating device as a key (blocks G 0 , G 1 and G 2 ). On the other hand, the title key TK is encrypted by a disc key DK, and is recorded as an encrypted title key Enc-TK on a disc (block G 3 ). The disc key DK is data obtained by reading a disc key block (or a disc key block) DKB from the medium and decrypting the disc key block DKB by the master key MK in the same way as the disc key in the reproduction dedicated device (block G 4 ).
[0075] A bundle of disc keys, in which the disc key is encrypted by a number of the master keys MKs, is recorded on the medium in advance. The disc key DK is decrypted and extracted therefrom by the master key MK embedded by the recording/reproduction device, and is utilized as the encrypted key of the master key MK.
[0076] On the reproducing side, the disc key block DKB is read out of the disc, and decrypted with the master key MK, so that the disc key DK is obtained (decryption section G 11 ). The disc key DK is used to decrypt the encrypted title key Enc-TK read from the disc (decryption section G 12 ). Subsequently, the title key TK is used to descramble the encrypted content read from the disc (descramble section G 13 ). The decrypted content is decoded by the A/V decoder (decoder G 14 ).
[0077] [0077]FIG. 12 is a block diagram of the schematic structure of the recording/reproduction device. In a dedicated recorder in a general consumer environment, illegal copying is rarely supposed. However, in a PC (personal computer) environment, it is easily possible to copy data read by a drive onto another recording medium.
[0078] In a PC environment, a recording medium is regarded as a peripheral device. At the input/output of the drive in FIG. 12, recording/reproduction operation is generally carried out with no concern to the contents of the data. Therefore, it is considered that the data on a data transmission/reception bus is illegally obtained. To prevent this illegal operation, it is necessary to use a bus authentication system.
[0079] [0079]FIG. 12 shows an AV encoder module H 101 and drive H 102 on the recording side, and a drive H 103 and AV decoder module H 104 on the reproducing side.
[0080] The components corresponding to those of FIG. 11 are denoted with the same reference numerals. In the AV encoder module H 101 , an encryption control section H 11 corresponds to the random number generation apparatus G 0 , disc key processing section G 4 , and encryption section G 3 of FIG. 11.
[0081] At the recording side, the title key TK which is an encryption key is encrypted by a disc key DK and made to be the encrypted title key Enc-TK. When the encrypted title key Enc-TK is to be transferred to a drive, it is necessary to transfer it through a bus authentication processing H 12 . In other processings, processings which are substantially the same as the respective processings in the CSS are carried out.
[0082] In FIG. 12, the A/V encoder G 1 and the content scrambling section G 2 are provided in an A/V encoder module H 101 at the recording side. An encode control section H 11 corresponds to the random number generating device G 0 , encrypting section G 3 , and disc key processing section G 4 of FIG. 11.
[0083] At the drive H 102 , ECC encoding by an ECC encoding section H 13 , modulating processing by a modulator H 14 , and writing processing onto a medium by a writing processing section H 15 are executed.
[0084] At the reproducing side, at the drive H 103 , signal reading from the medium by a signal reading section H 16 , demodulation processing by a demodulator H 17 , and decoding by an ECC decoding section H 18 are carried out. Further, at the time of reproduction as well, mutual authentication by a bus authentication section H 19 is executed between the drive H 103 and the A/V decoder module H 104 . After confirming the mutual authentication, the output of the ECC decoder H 18 is descrambled by a descrambling section G 13 , and decoded by an A/V decoder G 14 . A decode control section H 20 corresponds to the disc key processing section E 1 , decrypting section E 2 , and descrambling section E 3 in FIG. 11.
[0085] As described above, in the copyright protection system, the content is encrypted, and an encryption key is encrypted and the encrypted key is recorded in the recording medium (disc). However, in this system, the encrypted content and encrypted key are opened digital signals in transmission, reception, recording, and reproducing paths.
[0086] The copy protection method using the encrypting technique described above effectively functions in a DVD-video disc or a DVD-ROM disc on which previously encrypted information is recorded. However, in the case of a DVD-RAM or the like on which users can newly record information, the following problems arise.
[0087] (1) In a recording device that general users utilize, it is difficult to introduce a strong and low-priced encrypting device.
[0088] (2) It is difficult to manage an encryption key at the time of encryption. When encrypting and decrypting are carried out at the information recording device side, there is a high possibility that copying of information, for which copy protection is desired, can be easily carried out.
[0089] (3) If the encrypted content and encrypted key are copied as a whole, an illegal disc which can be reproduced by a regular device is made (when there is no concealed region).
[0090] (4) When an audio signal is processed, it must be processed in units of a large number of files (compositions). Therefore, it is difficult to maintain a copyright protection function for a request to manage in file units.
[0091] (5) As described above, it is difficult for a conventional encrypting technique to, as it is, effectively function in the copy protection of digital information signals. When encrypted recording information is reproduced, decrypting processing is carried out in the reproduction processing, and depending on the processing of the decrypted digital signal, the possibility of illegal copying still remains. In particular, by copying the encrypted information and the encrypted key as a whole, there is the possibility that a large quantity of copied recording media can be prepared.
[0092] As in the case of the DVDs, if various types of media such as read-only DVD-ROMs, and recordable DVD-Rs, DVD-RWs, and DVD-RAMs or the like are present, it is difficult to distinguish whether the digital signal recorded on the recording medium is an original signal or an illegally copied digital signal.
[0093] With respect to this problem, a similar problem arises in other recording media. Therefore, from the standpoint of copyright protection, it is desirable that information signals are encrypted such that only correct systems can decrypt, and it is determined whether the input digital signal is an original digital signal or an illegally copied signal at the entrance of the reproducing side. If a portion of the protection system is built in a region which general users cannot process, the ability of copyright protection can be largely improved.
[0094] That is, in the conventional copyright protection system, the transmission/reception or the recording/reproducing is performed by open data processing method. Moreover, means for encrypting the content constitutes the protection system. Therefore, there is a possibility of occurrence of an illegal action such as the copying of the encrypted data as it is. To prevent such illegal action, the concealment information region including the specific data needs to be secured in a part of the recording medium or a part of the transmitted/received information.
[0095] A similar technique in which the concealment information region is arranged in a part of data is described in Jpn. Pat. Appln. KOKAI Publication No. 11-86436. This technique comprises embedding the specific data in the data block with the error correction code added thereto. After the error correction of the data block, the specific data is corrected as an error. Therefore, after the error correction, the specific data disappears from the data block. The specific data can be extracted before the error correction.
[0096] As a result, if only the data subjected to the error correction is transferred to the outside, the specific data can be detected only in the drive, and the specific data can be used to enhance a copyright protection capability. That is, it is possible to use the specific data in distinguishing the control signal of the copyright protection such as the original signal and illegal copy signal. Since the specific data is replaced as an error signal in this method, the information is not included in the reproduced digital signal. Moreover, the correction processing is not performed by the general user who operates the system apparatus, and is therefore suitable for detecting the illegal operation. The specific data detected by this method can be the to be an electronic watermark which disappears. When the original digital signal is subjected to the correction processing, the specific data disappears. When the presence/absence of the specific data is judged, the original signal or the illegal copy signal can effectively be judged.
[0097] However, in this method, when the specific data is added to main data, the main data is destroyed. Therefore, on a side on which the main data is demodulated and reproduced, the presence of the specific data undesirably increases the error.
[0098] [II] Noted Respects
[0099] A method of embedding and recording the specific data in the data block with the error correction code added thereto is described in publications other than Jpn. Pat. Appln. KOKAI Publication No. 11-86436. However, in any case in which the specific data is embedded, the main data is destroyed. However, in the present invention, the error correction is prevented from becoming impossible.
[0100] In the present invention, the concealment information region is constructed in the data block with the error correction code added thereto. When the concealment information region is constructed, the main data is multiplexed/arranged. Even when the main data is destroyed by the specific data, a basic error correction capability is secured.
[0101] An example of the copyright protection system will concretely be described hereinafter. Moreover, it is assumed that the method of encrypting the content is a method for use in the DVD system in the description.
[0102] In FIG. 13, the video/audio information signal is compressed by the MPEG method, and further formatted in a digital data stream to which a reproduction control signal is added (data control section S 1 ).
[0103] The digital data is divided into the packet data by a unit of 2 Kbytes (sector formation section S 2 ). The sector numbers such as ID are added (ID addition section S 3 ). To protect the copyright, the data is encrypted or scrambled (contents encryption section S 4 ). The error detection code EDC is added to the encrypted data (EDC processing section S 5 ).
[0104] Thereafter, for a purpose of stabilizing the servo system in the reproduction operation, the data portion is data-scrambled with the random signal generated by the initial value determined by the ID information (scramble section S 6 ).
[0105] Here, different from the above-described data scramble for the encryption, in this data scramble, the data is scrambled with the open content. For the purpose, when the digital data is all “0”, the recording data becomes the repetition of the same pattern. In this case, there is a fear of occurrence of the problem that the tracking servo error signal cannot accurately be detected by the crosstalk of the adjacent track in the disc system. To execute the data scramble, the initial value of the M series generator is determined by the ID value. The signal from the M series generator is multiplied by the digital data, and the data scramble is performed. This prevents the data-scrambled recording signal from becoming the repetition of the same pattern. The data scramble for use in stabilizing the servo has been described only above. The data scramble described in the separate paragraph is used in the encryption processing for protecting the copyright of information.
[0106] The digital data subjected to the above-described processing is formed into the error correction code (ECC) block for the error correction processing by a unit of 16 sectors (ECC block formation section S 7 ). Here, the error correction codes of the inner-code parity PI and outer-code parity PO are generated (error correction code generation section S 8 ).
[0107] The outer-code parity PO is scattered/arranged into each sector and the recording sector is constituted by the interleave processing (PO interleave section S 9 ). The recording sector data is modulated by the modulation circuit (modulation/synchronization addition section S 10 ). The modulated signal is recorded in the disc via the driver and optical pickup head (PUH).
[0108] In a series of processing steps as described above, actual audio/video data is a large aggregate of the data sector as the A/V data file. The file management data and other control signals for managing the contents data are separated from the contents data and stored in the file. The encryption key of the content is encrypted and the encrypted key is similarly stored in the file. The encrypted keys of a plurality of files (content data files) may be collected and recorded in a specific place on the disc.
[0109] In the above-described system, the control data from the data control section S 1 is supplied to a specific data processing section S 11 . Here, the specific data is generated, and subsequently subjected to an error correction coding processing in an error correction coding section S 12 . The specific data subjected to the error correction coding processing is supplied to the modulation/synchronization addition section S 10 .
[0110] Examples of the above-described specific data include an encrypted key Enc-TK for encrypting/decrypting the content. In the copyright protection system, for example, a music content for several tens to hundreds of pieces of music is recorded in one recording medium (e.g., the disc). In this case, if a plurality of keys are collected and recorded in a specific place on the medium, the keys are used to realize a valid/invalid processing (setting) with respect to some pieces of music. That is, encryption or non-encryption can be set with respect to each piece of music. Thereby, the recording processing into the recording/reproducing media can efficiently be performed.
[0111] For the encrypted key Enc-TK, it is assumed that a data length of one key is 8 bytes. Then, even when the encryption keys of the contents for 1000 pieces of music are prepared, the capacity of the plurality of encryption keys is 8 Kbytes. The ECC block of the DVD system is constituted of 32 Kbytes (16 sectors), and 8 Kbytes is ¼ of the capacity.
[0112] Here, it is preferable that the data is completely stored in the ECC block. Then, with the content encryption key of 8 Kbytes (2 K data sectors×4), 8 Kbytes×4=32 Kbytes if it is multiplexed in four times, and the ECC block of 16 sectors is constituted. That is, when the encrypted keys are multiplexed/arranged, the ECC block can be constructed. The section which performs this processing is the above-described specific data processing section S 11 .
[0113] As described above, the error correction code is generated and added to the ECC block data in which the encrypted keys are multiplexed/arranged, and the recording sector is generated. Subsequently, a synchronous signal addition/modulation processing is performed and the signal is recorded in the disc. The section which performs this processing is the error correction coding section S 12 and modulation/synchronization addition section S 10 .
[0114] Here, to protect the system from the illegal person who destroys the copyright protection system and to enhance the system capability, the concealment information region for recording the specific data which cannot be handled by the general user is set in the data region of the disc. When the concealment information is prepared, the ECC block with the data multiplexed/arranged therein is used.
[0115] That is, in the present embodiment, a part of the ECC block is changed to the specific data, and the ECC block including this specific data is modulated and recorded in the disc. Additionally, in this case, even when the specific data is included, an error ratio of the ECC block is prevented from being deteriorated.
[0116] [0116]FIG. 14 is an explanatory view showing one concrete example of an embedded place of the specific data. Data packs 0 to 7 each of 2 Kbytes are multiplexed/arranged in 16 data sectors. In this case, a data pack 0 is arranged in sectors 0 and 8 , data pack 1 is arranged in sectors 1 and 9 , data pack 2 is arranged in sectors 2 and 10 , data pack 3 is arranged in sectors 3 and 11 , data pack 4 is arranged in sectors 4 and 12 , data pack 5 is arranged in sectors 5 and 13 , data pack 6 is arranged in sectors 6 and 14 , and data pack 7 is arranged in sectors 7 and 15 .
[0117] Here, the error correction codes of the outer-code parity PO and inner-code parity PI are generated with respect to the block in which 16 sectors are assembled. Subsequently, the outer-code parity PO is scattered/arranged by the interleave processing and thereby the recording sectors are constituted.
[0118] Thereafter, the sectors 1 , 6 , 11 excluding the rows in which the sector numbers are recorded and PO rows are used as the concealment information region. The specific data having its own error correction code exists in the region.
[0119] According to this arrangement structure, when the error correction processing is performed in the reproduction, and the original main data of the sector 1 is reproduced, the main data of the sector 9 is copied and used, and the data destroyed by the specific data can be restored. Additionally, needless to say, the specific data is extracted beforehand in the specific data reproduction.
[0120] Similarly, when the original main data of the sector 6 is reproduced, the main data of the sector 14 is copied and used, and thereby the data destroyed by the specific data can be restored. Moreover, when the original main data of the sector 11 is reproduced, the main data of the sector 15 is copied and used, and thereby the data destroyed by the specific data can be restored.
[0121] Therefore, according to this method, the specific data can be embedded in the ECC block without increasing the error ratio of the main data. Additionally, when the specific data is reproduced, the place (sector) with the specific data embedded therein is known beforehand from the ECC block, and the specific data is taken into the demodulation section and demodulated beforehand.
[0122] [0122]FIG. 15 shows another example of the embedded place of the specific data. In this example, the data packs 0 to 7 each of 2 Kbytes are multiplexed/arranged in 16 data sectors. In this case, the data pack 0 is arranged in sectors 0 and 1 , data pack 1 is arranged in sectors 2 and 3 , data pack 2 is arranged in sectors 4 and 5 , data pack 3 is arranged in sectors 6 and 7 , data pack 4 is arranged in sectors 8 and 9 , data pack 5 is arranged in sectors 10 and 11 , data pack 6 is arranged in sectors 12 and 13 , and data pack 7 is arranged in sectors 14 and 15 .
[0123] Here, the error correction codes of the outer-code parity PO and inner-code parity PI are generated with respect to the block in which 16 sectors are assembled. Subsequently, the outer-code parity PO is scattered/arranged by the interleave processing and thereby the recording sectors are constituted.
[0124] Thereafter, the sectors 1 , 6 , 11 excluding the rows in which the sector numbers are arranged and PO rows are used as the concealment information region. The specific data having its own error correction code exists in the region. For the ECC block, the original data of the sector 1 can be reproduced from the data of the sector 0 , the original data of the sector 6 can be reproduced from the data of the sector 7 , and the original data of the sector 11 can be reproduced from the data of the sector 10 .
[0125] [0125]FIGS. 16, 17, and 18 show examples of the sector in which the specific data is embedded. In the example of FIG. 16, the specific data is arranged in the rows excluding the rows in which ID and PO are arranged. The row with the ID arranged therein is first used in a detection processing during seeking in the reproduction processing. If another data is embedded in this row, the system capability is deteriorated. Each sector ID is different in the ECC block. Therefore, even when the main data of the row with the ID of a certain sector arranged therein is the same as the main data with the ID of another sector arranged therein, the value of PI differs with the row as a result. When this row is used in the specific data embedded place, the error increases even with the data copy from another sector in the reproduction processing. However, this does not apply to a case in which only the main data region excluding ID and PI is used, and the case is not different from the object of the present invention. However, for the other rows, even the PI region can be used as the specific data embedded place. Therefore, the system is more easily constituted, when the rows are not used.
[0126] In the example of FIG. 17, the rows in which the specific data is to be embedded are scattered. In this example, the specific data is embedded every other row excluding the rows in which ID and PO are arranged. With this scattering, the places in which errors are generated in the recording, reproducing, transmission, and reception processing can be scattered. Therefore, the correction capability of the specific data can be expected to be enhanced.
[0127] In the example of FIG. 18, the places in which the specific data is embedded are scattered/arranged in a column (longitudinal) direction. Additionally, in the examples of FIGS. 17, 18, the specific data embedded places in one sector are shown, but the specific data may of course be embedded over the plurality of sectors (see FIGS. 14, 15).
[0128] [0128]FIG. 19 is a block diagram showing the reproducing apparatus according to the present invention. In FIG. 19, the recording signal of a disc B 0 is read via an optical pickup head (PUH) B 2 . The read signal is amplified by a preamplifier, and binarized in a channel data read section B 3 , and channel data is extracted. A synchronization separation section B 4 separates the synchronous signal from the extracted binarized signal, and subsequently demodulated by a demodulation section B 5 . For example, 16 bit data is demodulated into 8 bit data using a conversion table. This digital data is supplied to an ECC block assembly section B 6 and constructed as the ECC block.
[0129] Subsequently, the ECC block is supplied to a specific sector and row separation section B 7 , and the specific data is extracted. The extracted specific data is supplied to a specific data detection section B 13 . Moreover, the ECC block is supplied to a specific row replacement section B 8 . Here, as described above with reference to FIGS. 14 to 18 , the portions in which the specific data is embedded are replaced with normal sector or row data. Subsequently, the ECC block (having no specific data) is supplied to an error correction processing section B 9 , and subjected to an error correction processing.
[0130] The data subjected to the error correction processing is descrambled in a descramble section B 10 . The descrambled data is formed as the data pack (see FIGS. 14 and 15) in a data sector section B 11 , and subsequently decrypted by the specific data (title key TK) given from the specific data detection section B 13 .
[0131] That is, the content data is reproduced, and the encrypted content is decrypted by the specific data (encryption key, and the like) detected beforehand. For the decrypted data, the compressed signal is expanded by the MPEG decoder, and demodulated as a digital video signal. The audio data is similarly demodulated, and a final audio/video signal is reproduced.
[0132] [0132]FIG. 20 shows a flow of sector data in the reproducing apparatus. For the reproduced ECC block including the concealment region (state J 1 ), first the data of the concealment region is separated (SP-Data 0 , SP-Data 1 , SP-Data 2 ). By this separation, the main data row is copied from the sector in which the data to be inserted in a blank region is arranged, and inserted in the blank region in the ECC block (state J 2 ). In the shown example, the data of the recording sector 9 is inserted in the sector 1 , the data of the recording sector 14 is inserted in the sector 6 , and the data of the recording sector 3 is inserted in the sector 11 .
[0133] The ECC block constituted in this processing is subjected to the error correction processing (state J 3 ). Subsequently, the final data pack is obtained (state J 4 ). On the other hand, the specific data signal of the separated concealment region is subjected to the unique error correction processing, and the specific data is detected.
[0134] In the conventional example, a large file data such as the video/audio data is processed with the data pack by the specific capacity. However, in recent years, the error correction block in the data processing has been handled and processed by a relatively large capacity unit. In this processing, a part of the management data or content is constituted to be complete by the error correction block unit.
[0135] This property has been noted. In the present embodiment, when the unit of the management data or content is smaller than the capacity of a large error correction block, the management data or content is multiplexed/arranged (used a plurality of times), and the whole unit is formed in the capacity of the large error correction block. Moreover, the concealment region is set using a part (sector) of the block.
[0136] Therefore, with the construction of the concealment region with respect to the optical disc in which the data can be read from the whole recording region by a general-purpose recording/reproducing apparatus, the concealment region can be set in a part of the main data block. Even in this case, the error of the main data by the construction of the concealment region is not generated. Similarly, even when all transmission data is open in the transmission/reception system, it is possible to construct the concealment region in the transmission data without deteriorating the error ratio.
[0137] Effective respects of the present embodiment described above will be described hereinafter.
[0138] 1. The concealment region for the specific data is secured in a part of the error correction coded block. Moreover, the part is replaced with the specific data, and transmitted or recorded. Here, for the block of the digital information, the replaced region forms the error data, and the error ratio is deteriorated. However, the error correction code is generated and added to the multiplexed/arranged data, it is possible to copy the original data to the specific data replaced portion before the correction processing from another region during the reproduction, and the error ratio is prevented from being deteriorated.
[0139] 2. Since a product code is constituted as the error correction code by the outer-code and inner-code parities, an effect of multiplexing increases.
[0140] 3. When the main data is multiplexed/arranged in a plurality of rows, for the portion of the data of the same content arranged in the row direction, code strings including the inner-code parities are constituted as the row having the same data content. As a result, even when some rows are destroyed by the specific data, the data of the destroyed row can be replaced with the data of the non-destroyed row.
[0141] 4. The main data is multiplexed/arranged in a plurality of columns, the portions of the data of the same content arranged in a column direction are the same, and therefore the code string including the outer code is constituted as the column having the same data. As a result, even when some columns are destroyed by the specific data, the data of the destroyed column can be replaced with the data of the non-destroyed column.
[0142] 5. A plurality of data sectors constitute one block. In the error correction coding processing, the data sectors are multiplexed/arranged, the error correction code is generated and added to the large block, and the error correction coded block is generated. Moreover, some data sectors are replaced with the specific data. As a result, the processing is possible by the sector unit.
[0143] 6. When a plurality of sectors constitute the error correction coded block, the IDs of different sectors are set to be different. A multiplexing write processing is performed such that only the main data region overlaps with the data of another sector. Moreover, the place where the specific data is to be embedded is only the main data region. Then, in the reproduction processing, it is unnecessary to subject the ID portion to a special processing.
[0144] 7. Since the error correction code is the product code, the multiplexed/arranged rows include the data of the same code string including the inner code, and an effect in a substitution processing increases during the reproduction processing.
[0145] 8. In the reproduction processing, the main data of the row destroyed by the specific data is constituted so that the main data is replaced with the main data of another multiplexed/written row and the correction processing is effectively performed. When the main data is replaced with the original main data content, the outer code corresponds to the main data. This is effective in the error correction code processing of DVD.
[0146] 9. Since the specific data is not protected by the ECC block of the main data, the error correction code is included in the own data series, the correction processing can thus be performed, and the specific data is securely detected.
[0147] 10. When the main data block and specific data use the same error correction system as the error correction code, the system is simplified.
[0148] 11. The data replaced with the specific data is destroyed. However, when the region of the specific data is specified beforehand, the data is destroyed. In the reproduction processing, when the data of another multiplexed/written region is copied, it is possible to quickly restore the original data.
[0149] As described above, according to the embodiments of the present invention, there can be provided a technique relating to the signal recording, transmission, reception, and reproducing method and apparatus, and signal recording medium in which the copy protection is further reinforced.
[0150] While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are 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 the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A signal processing method multiplexes/arranges digital data of a specific unit to form a predetermined unit, adds an error correction code to the predetermined unit to constitute an error correction coded block, replaces a part of the error correction coded block with specific data, and outputs the error correction coded block with the specific data being replaced to a transmission medium or a recording medium.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefits of European application No. 0881259.4 filed Jan. 23, 2008 and U.S. Provisional application 60/989,467 filed Nov. 21, 2007, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
The invention relates to a module of a nacelle of a wind turbine, a nacelle of a wind turbine, a wind turbine and a method for the assembly of a nacelle of a wind turbine.
BACKGROUND OF THE INVENTION
Wind power becomes more and more important. Parallel with the increasing significance of wind power wind turbines are getting larger and larger, which makes it more difficult to transport the large, in general preassembled and integrated wind turbine parts from the place of manufacture to the sites of erection, this can be onshore or offshore.
Normally a wind turbine comprises a few larger parts in form of the blades, the hub, the tower and the nacelle. Particularly the nacelle comprises a number of integrated main components such as a main shaft, a main bearing assembly, a gearbox, a generator, some power/control components, a transformer, a cooling system and so on, which are all arranged on a common bedplate and in a common nacelle housing. The bedplate has a yaw system to orient the nacelle towards the wind direction. Typically the nacelle is completely preassembled at the place of manufacture.
When a wind turbine is erected the blades, the hub, the tower and the preassembled nacelle are transported to the site of erection. The tower is erected, the nacelle is mounted on the tower, the hub is mounted on the nacelle and the blades are attached to the hub by means of at least one crane. Thereby not only the transportation in particular the transportation of the large and heavy nacelle is difficult, but also the mounting on the tower, which requires sufficient crane capacity to handle the complete nacelle weight.
Moreover the servicing of such a wind turbine is often very complicated and time consuming, in particular when one or more components of the nacelle have to be replaced.
SUMMARY OF INVENTION
It is therefore an object of the present invention to lay the foundations that the transportation and/or the assembly of at least a part of a wind turbine is facilitated. It is a further object of the invention to indicate a method for the assembly of a part of a wind turbine.
The first object is inventively achieved by a module of a nacelle of a wind turbine, which is separately designed, separately manageable and comprises a housing part, wherein the module is connectable to at least one further module of the nacelle, which is also separately designed, separately manageable and has a housing part, and wherein the housing part of the module builds in the assembled status of the nacelle, which comprises several modules, a part of the housing of the nacelle. Thus the invention pursues a modular concept or a modular design of a nacelle, wherein the single modules build in the assembled status substantially the nacelle and wherein preferably each module comprise at least one functional unit of a wind turbine, e.g. a generator, a transformer, a power unit, a control unit etc. Thereby the external housing part of the module forms a part of the external housing of the whole nacelle. Having the nacelle of a wind turbine divided into such separate modules it becomes possible to manufacture the modules at separate locations and to assemble the modules for forming a complete nacelle first during the installation of a wind turbine. This will facilitate not only the transportation of the modules, but also the specialization of manufacturing of certain modules at competence centres. Thereby a module is able to be transported or shipped completely, wherein in particular the housing part of the module provides mechanical and weather protection during transportation and storage of the module.
Moreover it becomes easier to carry out the installation of the nacelle with limited crane capacity, since the assembly may be carried out at height, installing one module at a time, in which case the crane requirements are determined not by the complete nacelle weight but by the weight of the heaviest module.
Furthermore in case of a failure of a complete module the respective module is able to be replaced.
In a variant of the invention the module comprises connection means for connecting the module to at least a further module. Preferably the connection means of the module comprises at least one flange for connecting the module to the further module. Thus when a second module is arranged on a first module the flange of the second module and the flange of the first module, which are arranged oppositely to each other, are able to be bolted together. In such a way the nacelle is built stepwise until all required modules are arranged.
According to a further variant of the invention the module comprises as functional unit a generator, a retaining arrangement, a cooling unit, a control unit, a transformer or a main-shaft-bearing arrangement. According to this variant of the invention there are different specialised modules in form of a generator module, a retaining arrangement module, a cooling module, a control module, a transformer module and a main-shaft-bearing arrangement module.
In an embodiment of the invention the module comprises a substantially explosion and/or a fire resistant wall. In particular the transformer module comprises such an explosion and/or fire resistant wall next to a further module. Preferably the transformer or power-unit module is arranged on the rear end of the nacelle and comprise the mentioned explosion and/or fire resistant wall to the afore positioned module. According to a further embodiment of the invention a module, preferably the transformer or power-unit module comprises a bursting disc on its free end. In case of an explosion or a fire, the bursting disc, possibly being a part of the outer shell of the transformer or the power-unit module, will distort or be blown out to minimise blast effects in the nacelle and to protect the other modules and any personnel in the nacelle. In that situation the transformer or the power unit module is able to be replaced without replacing any other component.
According to a further variant of the invention the module comprises at least one functional mechanical and/or functional electrical interface for connecting the module functionally to a further module. In that way the whole mechanical and electrical interconnection throughout the nacelle is able to be achieved.
According to another embodiment of the invention the module and the housing part of the module respectively is self-supporting. So each module is able to be arranged on another module without the need of any supporting means for a module.
The object of the invention is also achieved by a nacelle of a wind turbine comprising several separately designed, manageable and replaceable modules, wherein each module is connectable to at least one further module and has a housing part, wherein the modules build in the assembled status substantially the nacelle, and wherein the housing parts of the modules build at least partially the housing of the nacelle. Thereby all variants and advantages mentioned in relation with a single module apply also to the nacelle.
According to a further variant of the invention at least one module comprises a helihoist platform. In this way it is possible to get to the nacelle by helicopter even under bad weather conditions.
In an embodiment of the invention the nacelle comprises on its one end an end plate, which can be a bursting disc.
The object of the invention is also achieved by a wind turbine comprising at least one module as disclosed before and/or a nacelle as disclosed before.
The further object of the invention is achieved by a method for the assembly of a nacelle of a wind turbine as disclosed before, wherein modules as disclosed before are arranged in series on a wind turbine tower, wherein a module comprising a retaining arrangement or a main-shaft-bearing arrangement is arranged on the tower and at least one further module is arranged on the module comprising the retaining arrangement or the main-shaft-bearing arrangement. In this way the nacelle of a wind turbine is able to be assembled stepwise during the erection of the wind turbine on site with limited crane capacity. Thereby the modules are mounted one by one aloft.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will in the following be explained in more detail with reference to the schematic drawings, wherein
FIG. 1 shows a nacelle comprising several single functional modules arranged on a tower of a wind turbine and
FIG. 2 shows another embodiment of a nacelle comprising several single functional modules.
DETAILED DESCRIPTION OF INVENTION
FIG. 1 shows schematically a nacelle 2 according to the invention arranged on tower 3 of an only partly shown wind turbine 1 . The nacelle 2 comprises several single, separately designed, separately manageable and separately replaceable modules 4 - 8 according to the invention.
In case of the present embodiment of the invention a module 5 comprising a retaining arrangement in form of a retaining arm 9 is arranged on the tower 3 . More precisely the module 5 and the retaining arm 9 respectively is attached to a tower flange 10 and turnable around the axis A of the tower 3 by means of a not explicitly shown yaw system to orient the nacelle 2 towards the wind direction. The module 5 comprises a housing part 51 . In case of the present embodiment of the invention the housing part 51 is self-supporting and comprises on the front end and the rear end connection means in form of flanges 52 , 53 .
A self-supporting module 4 comprising a generator and a housing part 41 with a connection flange 42 on the rear end of the housing part 41 is arranged on the front end of the module 5 . Thereby the flange 42 of the housing part 41 and the flange 52 of the housing part 51 as well as a stationary part of the generator and the retaining arm 9 of the module 4 are bolted together.
A conventional hub 13 is attached to the module 4 and a rotary part of the generator respectively by means of bolts.
A self-supporting module 6 , comprising a cooling unit and a housing part 61 is arranged on the rear end of the module 5 . The housing part 61 of the module 6 comprises on the front end and the rear end connections means in form of flanges 62 , 63 . The flange 53 of the housing part 51 of the module 5 and the flange 62 of the housing part 61 of the module 6 are bolted together, so that the module 6 is attached to the module 5 .
A further self-supporting module 7 comprising a control unit and a housing part 71 is arranged on the rear end of the module 6 . The housing part 71 of the module 7 comprises on the front end and the rear end connections means in form of flanges 72 , 73 . The flange 63 of the housing part 61 of the module 6 and the flange 72 of the housing part 71 of the module 7 are bolted together, so that the module 7 is attached to the module 6 .
A last self-supporting module 8 comprising a transformer and a housing part 81 is arranged on the rear end of the module 7 . The housing part 81 of the module 8 comprises on the front end and the rear end connections means in form of flanges 82 , 83 . The flange 73 of the housing part 71 of the module 7 and the flange 82 of the housing part 81 of the module 8 are bolted together, so that the module 8 is attached to the module 7 .
In case of the present embodiment of the invention the transformer module 8 comprises additionally a substantially explosion and/or fire resistant wall 15 on the front side next to the module 7 .
An end cap or end plate 14 is attached to the rear end of the module 8 . The end plate 14 closes the rear end of the module 8 . Thereby the end plate 14 is bolted with the flange 83 . In case of the present embodiment of the invention the endplate 14 is a bursting disc or a kind of bursting disc. Thus in case of explosion or fire in the transformer module 8 the bursting disc will distort or be blown out to minimise blast effects in the nacelle 2 and to protect the other functional modules 4 - 7 as well as any personal in the nacelle together with the explosion and/or fire resistant wall 15 . Because the transformer module 8 is the last module of the nacelle 2 it can be replaced in such a situation without replacing any other module or component of the wind turbine 1 .
If necessary also the other modules are able to have an explosion and/or fire resistant wall and/or a bursting disc.
As can be seen from FIG. 1 the single, separately designed, manageable and replaceable modules 4 - 8 are arranged in series in relation to a centre axis B on the tower 3 of the wind turbine 1 and build in the assembled status the nacelle 2 of the wind turbine 1 . The housing parts of the single modules 4 - 8 are in such a way aligned to each other, that the single housing parts 41 , 51 , 61 , 71 and 81 build together with the end plate 14 the housing or canopy of the nacelle 2 . Thus there is no separate or additional housing surrounding the single modules 4 - 8 necessary. In fact the housing parts 41 , 51 , 61 , 71 , 81 and the end plate 14 are connected with each other water tight, e.g. by means of appropriate sealings.
All or some modules 4 - 8 can in a not shown manner comprise functional mechanical and/or functional electrical interfaces as wells as mechanical components and cables for mechanical and/or electrical interconnections of the modules 4 - 8 . There is e.g. a not shown electrical interconnection comprising functional electrical interfaces and cables between the generator module 4 and the transformer module 8 . Examples of functional mechanical interfaces of modules are the stationary part of the generator of the module 4 as a first functional mechanical interface and the retaining arm 9 of the module 5 as a second functional mechanical interface.
A flange of a housing part preferably runs along the perimeter of the housing part, wherein the housing part is able to have a ring-shaped cross section or a cross section having a different form.
The module 5 comprising the retaining arm 9 , which can also be identified as a load-bearing module, is carrying the weight and the load of the hub 13 , the not shown three rotor blades attached to the hub 13 and the modules 4 - 8 , thereby transferring the load to the tower 3 .
As disclosed each module 4 - 8 can be self-supporting, wherein the housing part of each module typically is the weight- and load-carrying component of the respective module 4 - 8 .
As already mentioned, having the nacelle 2 of the wind turbine 1 divided into the single modules 4 - 8 it becomes possible to manufacture the single modules 4 - 8 at separate locations and to assemble the modules 4 - 8 for forming a complete nacelle 2 first during the installation of the wind turbine 1 . This facilitates the transportation of the modules 4 - 8 to the site of erection as well as the specialization of manufacturing of certain modules at competence centres. Each module 4 - 8 is able to be transported or shipped completely, wherein in particular the housing part and an additional packaging of the module at both ends of the module provides mechanical and weather protection during transportation of the module.
Further on in case of a failure of a complete module the respective module is able to be replaced.
FIG. 2 shows another embodiment of a modularised nacelle 12 of a wind turbine 21 in an exploded view.
In case of this embodiment a module 22 comprising a main shaft bearing arrangement or a load bearing arrangement including a main shaft 16 and two main bearings 17 , 18 is arranged on a schematically shown tower 33 . A module 23 comprising a generator is arranged on the rear end of the module 22 , wherein the rotor of the generator is connected to the pivotable main shaft of the main shaft bearing arrangement. A hub 13 is attached to the main shaft 16 of the module 22 .
A module 24 comprising a control unit is arranged on the module 23 , a module 25 comprising a cooling unit is arranged on the module 24 and a module 26 comprising a transformer is arranged on the module 25 . The transformer module 26 is closed with an end plate 27 .
As can be seen from FIG. 2 the nacelle 12 of a wind turbine can be modularised to such an extent that customised solutions are implemented simply by adding or deleting modules. The module 25 comprising a cooling unit can be e.g. an offshore cooling/climate control module 25 a or a hot climate cooling module 25 b . Also the transformer module 26 is available in different designs, e.g. as standard transformer module 26 a or as transformer module 26 b with helihoist platform 28 . In the same way there can exist alternative designs concerning the other modules 22 - 24 .
The connection of the modules 22 - 26 can be achieved as disclosed in the context with the embodiment of FIG. 1 . The modules 22 - 26 b have preferably substantially the same properties as the modules 4 - 8 .
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The invention concerns a module of a nacelle of a wind turbine, which is separately designed, manageable and comprise a housing part. The module is connectable to at least one further module of the nacelle, which is also separately designed, manageable and has a housing part, wherein the housing part of the module builds in the assembled status of the nacelle, which comprises several modules, a part of the housing of the nacelle. The invention concerns also a nacelle comprising several such modules, a wind turbine comprising such a nacelle as well as a method for the stepwise assembly of such a nacelle aloft.
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This application is a continuation-in-part of U.S. application by the inventors hereof, Ser. No. 08/555,527 filed Nov. 9, 1995, issuing as U.S. Pat. No. 5,702,199 on Dec. 30, 1997, and which is hereby expressly incorporated by reference herein.
FIELD OF INVENTION
This invention relates to pavements and paving materials and the use of recycled plastics in pavements and paving materials. More particularly, this invention relates to pavements, to paving materials for use therein, and to methods for making paving materials and pavements having unsorted, residual or other recycled or waste plastic as a component of the paving material or pavement.
BACKGROUND OF THE INVENTION
Paving materials such as asphaltic concretes that are used for roadways, parking areas, walkways and other traffic surfaces have been the subjects of various efforts to improve their properties. Some of these efforts have involved the addition of polymers, including plastics, in attempts to improve the flexibility, strength and life of the paving material. Such efforts have proved either ineffective or too costly.
The increasing need to dispose of or find new uses for previously used or recycled plastics and waste plastics has given incentives to efforts to introduce plastics from waste sources into building or paving materials, either to facilitate their disposal where it is hoped that their introduction does not degrade building or paving material and does not increase its cost, or where it is hoped that their introduction will provide a cost effective improvement in the properties of the building or paving materials. Work has been done to utilize low density plastic and films of selected and graded recycled plastic materials as an additive to the asphaltic binder component of asphaltic concrete paving material in an effort to improve the flexibility and reduce the propensity of the paving material to crack. This effort requires that the recycling task to collect suitable plastic material be selective, or that the material be specifically sorted from a general mixture of recycled plastic material. Such recycled plastic material has a cost that is significantly greater than that of the general ungraded or unsorted recycled plastic material mixture or of the residual recycled plastic material from which more useful grades have been removed.
For example, it has been proposed to melt polystyrene foam with asphalt, to add sand, and to mold the material as a concrete substitute, thereby utilizing the waste plastic. Further, it has been proposed to add waste polyethylene to asphalt for road construction to increase pavement durability. Decreased deformation resistance and increased hardness and ductility have been reported by adding other plastic waste in amounts of, for example, eight percent to paving compounds containing aggregate, where the plastic waste includes specific plastics made of specific combinations of low density polyethylene, cyclophane, cellophane, polypropylene, and polyvinyl dichloride. Fiber reinforced plastics and chopped glass have been proposed for addition to add to asphalt to improve wear resistance and water permeability.
Proposals to use specific waste plastics as additives to asphalt mixes have had the disadvantage of requiring specific collection of the individual material or the sorting of the desired material from the generally collected plastic waste. Such efforts calling for specific plastics are therefor costly. Furthermore, such efforts do little to solve the problem of utilization of vast unsorted, unsortable or unclassified bulk mixtures of plastic waste.
Waste plastics are found in several forms. In one form, bulk masses of particular identified plastic materials are produced as waste in the plastics industry. In other forms, plastics are found in the form of discarded articles and containers. Some such plastics, particularly plastic bags and plastic bottles, are collected in recycling activities. Recycled plastic bottles are classified according to a nationally recognized identification system known as the Plastic Container Code System (PCCS) into seven classes that are being identified by markings on the bottles. These classes are: class 1, polyethylene terephthalate (PETE), class 2 high density polyethylene (HDPE), class 3, vinyl and polyvinyl chloride or PVC (V), class 4, low density polyethylene (LDPE), class 5, polypropylene (PP), class 6, polystyrene (PS) and class 7, all other resins and layered multi-material. For convenience, these classes are used below to identify waste plastics that are also in a form other than that of bottles for which the classes were specifically established.
Recycled plastics of types corresponding to PCCS classes 1 and 2, and sometimes classes 4, 5 and 6, whether in the form of used containers or other forms made of the materials, have been sorted from the general mass of recycled material or separately collected, all at increased cost. Bulk mixtures of recycled plastics from more than one of the PCCS classes, particularly materials from class 7 and from class 3 when mixed with material from other classes, generally have been regarded as lacking utility and are accordingly routed to landfills. Such materials have lacked an alternative use or manner of disposition.
The employment of plastics in asphalt mixes has presented various problems. Many of the plastic additives have lacked an ability to bond to or combine with the asphalt binders of the mix. Chemical treatments have been proposed, but such treatments have been ineffective, add to the cost, and introduce additional noxious and toxic substances into the process, aggravating the waste disposal problems.
Accordingly, there remains a need for a low cost manner of enhancing the properties of paving material and there remains a need for a use of residual plastic waste, particularly unclassified or unseparated materials or materials of mixed classes.
SUMMARY OF THE INVENTION
An objective of the present invention is to improve the properties of pavements and of paving materials, particularly asphaltic concrete materials, and most particularly, to improve the strength and useful life of the pavements made of the paving materials.
A particular objective of the present invention is to improve the properties of paving materials at a minimum increase in cost or at a savings in cost from that of the standard asphaltic paving material.
A further objective of the present invention is to provide a use for recycled or waste plastic materials, particularly thermosetting and other PCCS class 7 materials, and other combinations of materials of more than one class, particularly classes 3 through 7.
A further objective of the present invention is to provide a method of making a paving material, particularly an asphaltic paving material, and of utilizing waste plastic in paving material manufacture.
According to principles of the present invention, there is provided a method of making a paving material that includes the step of providing bulk residual plastic waste materials including materials of the types corresponding to PCCS classes 3-7, and preferably including materials of more than one such class, the step of processing the plastic to a form suitable for combining with asphalt, and the step of combining the processed plastic with asphaltic binder. Preferably, the processed plastic serves as an aggregate in the paving material, and preferably replaces at least some of, or combines with rock aggregate to form an asphaltic concrete paving material. Further, the process of the invention may include the step of forming a pavement with the paving material. In addition, a paving material and pavement are provided that are made according to such process.
According to the preferred embodiment of the invention, recycled plastic material that is unclassified, or is in the form of bulk material containing plastics corresponding to more than one of the PCCS classes 3 through 7, or contains thermosetting plastics and other plastics of PCCS class 7, are provided. The plastic material is either pelletized, is shredded or otherwise mechanically granulated, or otherwise formed into particles. Conventional asphaltic binder material and graded aggregate that includes rock particles ranging in size are also provided. The binder and plastic material are, in the most common application of the invention, premixed as an aggregate component with binder and rock aggregate and applied as a pavement. In alternative applications, the processed plastic is mixed with the binder, then applied as a slurry, for example over an existing pavement, is applied over a base or a prelaid layer that may contain a rock aggregate, with which it combines to form a pavement.
Typically the aggregate will include from five to seven sieve sizes ranging from no. 40 to three-fourths inch in size, or preferably from no. 200 to one inch in size. The particles of plastic are preferably of a size that corresponds to one of the intermediate sizes of the rock aggregate. Preferably further, the paving material is formed by mixing from five to twenty-five percent or more of the plastic particles, measured by volume, with the rock aggregate and the asphaltic binder. In one preferred form, an amount of rock aggregate is used which may be varied from the standard ratio mixture of rock aggregate and binder, and preferably by reducing the amount of mid-range or correspondingly sized rock aggregate by an amount not more than the amount of added plastic, and preferably by an amount that is somewhat less than the amount of added plastic. Preferably, the particles of plastic are in the one-eighth to one-quarter inch sieve range, and may be three-eighths inch or larger. The particles of plastic will be generally flatter and more elongated in shape than the shapes of the particles of the rock aggregate component of the mixture.
Further in accordance with the preferred embodiment of the present invention, the plastic particles are further processed to activate the surfaces of the plastic particles to increase the surface tension and to cause free or active carbon atoms to be present in the molecules of the plastic material at the particle surface. The activation of the particle surfaces is preferably performed with minimal heating, burning or melting of the plastic, and may be achieved by exposing the surface to high energy treatment-gas atoms, ions or molecules for a limited duration. Such a gas may be in the form of a flame, or in the form of a plasma or corona, or other electrically or otherwise enhanced gas or vapor, that will cause the activation or increased energization at the surfaces of the plastic particles.
Treatment of the plastic is achieved, in one embodiment described below, by exposing the surfaces of granulated plastic particles to a reducing flame, preferably by exposing the particles to the outer envelope of such flame. The exposure may be carried out by passing the particles on a conveyor through the flame, dropping the particles through a flame treatment tower or otherwise contacting the particles briefly with the flame.
The use of a ionized or plasma enhanced gas to activate the particle surfaces is also suitable, and may be carried out by transporting the particles on an electrically conductive conveyor. Other forms of gas reactant treatment may be used to activate or etch the surface. In a preferred process, granulated plastic particles are fed into the top of a vertical plasma treatment column with the gas that occupies the space between the particles being ionized by arrays of electrodes along the height of the column. The ionized gas in the column plasma treats the surfaces of the particles as the particles pass through the column from top to bottom, so that the particles are discharged from the bottom of the column with highly stable activated surfaces.
The activated surfaces of the plastic particles are thought to enhance the bonding between the asphaltic binder and the plastic particles and do so with minimal or insignificant heating of the plastic. Such plastic particles are blended with the asphaltic binder and with rock aggregate at normal low temperatures, such as at temperatures below 300° F. The treated plastic is preferably used to form a paving material by combining it with a binder before the activated state of the surfaces of the particles decays. Typically, this time ranges from days to months, depending on the treatment process used, the extent of the treatment and other various treatment parameters such as the energy level of the treatment gas and the time duration of the particles in the gas during treatment.
The present invention provides a paving material and pavement that is has is believed to be up to fifty percent or more stronger than the required strength of road paving materials or than standard asphaltic concrete that is not modified with the addition of the plastic particles as described above. The invention provides a use for the low utility or otherwise useless recycled and waste plastic compositions, and provides a use for unclassified or residual class plastic material. The cost of the added plastic material is very low, with some untreated plastic material approaching no cost at all, compared with the cost of its disposal. The invention allows the reduction in the total amount of paving material used for making a pavement in proportion to the increased strength of the material, thereby providing a cost savings in the reduced amount of asphaltic concrete required, which may more than offset the cost of providing, treating and blending the plastic.
These and other objectives and advantages of the present invention will be more readily apparent from the following detailed description of the of the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart of one preferred embodiment of a method according to the present invention;
FIG. 2 is a diagram of a shredder suitable for use with the method of FIG. 1;
FIG. 3 is a diagram of a flame treatment tower suitable for use with embodiments of the method of FIG. 1.
FIG. 4 is a diagram of an alternative form of flame treatment apparatus suitable for use with embodiments of the method of FIG. 1;
FIG. 5 is a diagram of one form of a plasma treatment apparatus suitable for use with embodiments of the method of FIG. 1.
FIG. 6 is a cross-sectional diagram of a roadway according to certain embodiments of the present invention; and
FIG. 7 is an enlarged view of a portion of FIG. 6.
FIG. 8 is a diagram, similar to FIG. 5, of an alternative form of a plasma treatment apparatus suitable for use with embodiments of the method of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of the invention is set forth herein in the form of a description of a test or example of a process (FIG. 1) of making a paving material. In accordance with this preferred embodiment of a method of the present invention, a standard asphaltic mix is selected (70). One such suitable mix is, for example, New Mexico State Highway and Transportation Department (NMSHTD) type I A asphaltic mix. Further, a mixture of local rock aggregate suitable for asphaltic concrete for use in highway construction is selected (71). Such a rock aggregate mixture used in this example includes particles of the following sizes, as set forth in Table 1:
TABLE 1______________________________________Sieve Size Percent Passing______________________________________1 inch 1003/4 inch 861/2 inch 673/8 × inch 57No. 4 42No. 10 34No. 40 21No. 200 5.1______________________________________
Where aggregate is used as a component of the paving material, as in the illustrated example, this step (71) may be performed at any time prior to the blending step (75) discussed below. In other applications, the aggregate providing step (71) is omitted from the paving material blended in step (75), but may be in a previously applied layer of pavement to which the blended plastic and binder are to be applied.
In the example, a volume of bulk recycled plastic material is selected (72).
The bulk plastic material may be ungraded or unsorted and thereby predominantly contain plastics of types corresponding to PCCS classes 1 through 7. Preferably the plastic is a residual ungraded bulk of recycled plastic from which most of the items of class 1 (polyethylene terephthalate) and class 2 (high density polyethylene) have been removed. It is also contemplated that some of the class 4 plastic (low density polyethylene) and low density foam plastic from class 6 (polystyrene) may have been removed, as well as other grades or classes for which other uses have been found. The bulk material may contain plastic bottles and other waste plastic articles, layered, thermosetting or miscellaneous plastic articles from class 7, PVCs from class 3, or masses of waste plastic from plastic production and molding industries, for example. In the example, a representative average sample including primarily an assortment of plastic waste corresponding to the plastics of classes 3 through 7 was selected. The plastic waste may include used containers but may contain, in addition or in the alternative, other plastic waste having compositions corresponding to the PCCS classes.
Then, the plastic material is granulated (73). The granulation process typically involves the shredding of the plastic material 30 in a shredder 31 that employs a plurality of knife blades 32 to reduce the mass of plastic to a uniform blend of particles 33, as illustrated in FIG. 2. The particles include a large percentage of generally flat flake or plate-like pieces that are generally more elongated than the particles of the rock aggregate referred to above. In the example, the sizes of the granulated plastic particles included 18 percent that passed sieve no. 10, with all of the particles passing sieve no. 4. It is contemplated, however, that, for use with the rock aggregate described above, most of the plastic particles will be in the 1/4 inch to 3/8 inch range, and perhaps larger. They will nonetheless be smaller than, and preferably less than half the size of, the largest rock aggregate particles for applications in which the plastic particles are to be blended with the aggregate before paving to form an asphalt mix.
The granulated plastic particles are then treated (74) to activate the particle surfaces. The manner of activating the surfaces of the plastic particles is, according to one embodiment of the invention, by exposing the surfaces of the particles to a flame treatment. With the flame treatment, It is preferable to expose the plastic particles to the flame intermittently, if increased exposure is desired, than to maintain the flame constantly, which could unnecessarily heat the plastic, or could burn or melt the plastic. The flame in this embodiment is preferably a reducing flame.
A reducing flame may be produced by natural gas, propane, or other fuel. In the example, an oxyacetylene reducing flame is used and the plastic particles were spread on a screen and brushed repeatedly with the flame from above and below, using a torch maintained at a distance of about twelve inches from the flame, with agitating and turning of the plastic particles. The duration or dwell of the flame on any of the particles is preferably kept sufficiently short to avoid any significant melting or burning the particles or causing a visually perceivable change in the appearance of the plastic particles. A small percentage of the plastic that might be of the lower density, lower melting point types or include exceptionally thin sheet shreds or narrow fibers may, in such a process, melt or char without adversely affecting the process or paving material to be produced.
In one form of the preferred embodiment of the invention, it is contemplated that the activating gas treatment of the granulated plastic particles 33 be carried out in a flame treatment tower 40, as illustrated in FIG. 3. Such a tower may be a vertically elongated cylindrical column 41 having a plurality of inwardly directed, and possibly upwardly inclined gas jets 42 spaced around the column and at vertical intervals. The fuel to oxygen mixture of the flame is set to create a slightly oxygen poor or reducing flame throughout the center of the column through which the granulated particles are dropped. Depending on the height of the column used, the particles 33 may be repeatedly dropped through the flame. Use of a flame treatment tower 40 in which the particles are dropped through the flame, rather than the use of a conveyor or other structure to support the particles for treatment with the flame, avoids possible sticking to the support caused by a softening or melting of a small percentage of the plastic material in the flame. Such a tower should have a cool air region 43 at the bottom of the tower to facilitate a rehardening of any softened plastic, and the collection of treated particles 45 at the bottom of the tower should include a fluidized air bed 44 or agitating mechanism to avoid a sticking together of the treated particles.
In an alternative form of the preferred embodiment of the invention, flame treatment is performed in an inclined drum tumbler 50, as illustrated in FIG. 4. The tumbler 50 is in the form of an elongated cylindrical barrel 51, inclined at less than 20 or 25 degrees to the horizontal, and preferably at about 10 to 15 degrees to the horizontal. The barrel has a plurality of longitudinal vanes 52 running generally parallel or slightly spiraled relative to the axis of the barrel. The reducing flame 53 is made to flow upwardly through the center of the barrel around the axis thereof as the barrel is rotated. The granulated plastic particles 33 are fed into the top of the barrel and proceed to be tumbled through the flame several times as they proceed toward an outlet at the bottom end of the inclined cylinder 51. The constant rotary motion of the barrel, which is kept relatively cool, prevents the sticking to the barrel of any particles 45 that might have been softened.
It is further contemplated that the particles may, for some uses, be pelletized following shredding or granulation and prior to the activating treatment. To pelletize the particles of plastic, the particles may be fed, for example, from a hopper into a pelletizing extruder in which a mild heating element would heat the particles to soften some of the plastic components and promote sticking of the particles. An auger then compresses the warmed particles and extrude them through an extrusion die to be cut into pellets of more or less uniform size. Such pellets may then be treated as described above.
In other embodiments, a plasma, corona or ionized gas may replace or be combined with the flame. For example, as illustrated FIG. 5, treatment is carried out by exposing the particles to ionized gas, plasma, corona discharge 60 or other electrically energized treatment medium. Such a treatment may be carried out by presenting the plastic particles 33 upon a conveyor 61, which may be effective to maintain charge on the plastic particles, while exposing the particles to the treatment medium 60.
An alternative apparatus 80 for plasma treatment of the particles is illustrated in FIG. 8, in which a vertical plasma treatment tower or column 81 is employed. The column 81 is equipped at its top with a hopper fed infeed auger or other loading device 82 which is capable of loading a continuous stream of granulated waste plastic particles into the column 81 from its top. The particles are preferably allowed to fill the column and form a loosely stacked bulk mass of the particles 83 in the hollow interior of the column 81.
Opposite sidewalls of the column 81 are provided with electrodes 84 in the form of arrays of pins, electrically insulated from a housing 89 of the column 81, which is preferably formed of a metal and grounded. The electrodes 84 connected to a high voltage power supply which energizes the electrodes 84 sufficiently to produce an electrical discharge in the gas that occupies the spaces between the particles in the column 81. Preferably, the discharge results in a purplish-blue glow resulting from the ionization of gas within the column 81. The electrodes 84 are preferably located on opposite sides of the column 81 in the upper half of the column and on the front and back of the column 81 on the bottom half of the column 81 to better insure uniform treatment of the particles as they descend vertically down the column.
At the bottom of the column 81 is provided an outfeed auger 85, which removes treated particles of bulk plastic material from the bottom of the column 81. After the column is filled, the plasma electrodes are energized, and the plasma treatment has been applied to the particles in the filled column 81 for a sufficient period of time to activate the surfaces of the particles, the outfeed auger 85 and the infeed auger 82 are operated at the same bulk transfer rates to cause a constant volume flow of particles into the column at the top, downwardly through the column 81 and the plasma, and out of the outfeed 85 at the bottom of the column 81. An initial quantity of about one thousand pounds of treated plastic material is run out of the apparatus 80 when it is first started before fully treated plastic is consistently produced. This initial quantity is collected and refed into a hopper to the infeed auger 82 and retreated. The column 81 may be provided with air jets to free the bulk plastic material should it become compacted in the column.
In the plasma treatment of the plastic particles, the surfaces of the particles are preferably treated to a desired surface tension, preferably which produces an ASTM wettability measurement of 50-55 dynes/cm, and preferably of about 68-70 dynes/cm or higher. For a nominal treatment rate of approximately 500-550 cubic feet per hour of plastic, which, for example, may have a bulk density of about 27 pounds per cubic foot, the column 81 is preferably 10 to 14 feet tall with an approximately 13 inch square internal cross-section. Preferably, the electrodes 84 are energized to a high voltage determined by the geometry of the column 81 and electrodes 84 to ionize the gas within the chamber. The high voltage is supplied from a rectified output of rectifier 88 connected to a center-tapped secondary winding of a high voltage transformer 87. In one preferred embodiment, the transformer is connected to an input 86 of about 440-480 volts AC, 60 Hz, drawing about 30 input amps. The output of the secondary winding of the transformer for an apparatus of this configuration and capacity is about 5 kVA. This power is adequate for producing paving material in these quantities. For larger scale paving projects one skilled in the art can appreciate that larger scale equipment is desired and providing such would be within such person's skill.
Electrodes 84 may take many configurations and forms. For example, the arrays of electrodes may be arranged in a 1/4 inch grid pattern on polyethylene sheets 90. Contact of the electrodes 84 to the output rectifier 88 can be made with the use of conductive oil layer 92 sealed in a thin volume that communicates with the outer ends of the electrodes 84. Plasma treatment equipment and the technology for designing and producing such equipment is available from Electro Engineering, 2319 Grissom Drive, St. Louis, Mo. 63146.
The plasma treatment can be satisfactorily performed where the gas between the particles in the column 81 is air. Much higher rates of productivity are expected where an inert gas such as argon is used. The argon tends to support the plasma better and is less likely to result in a burning of the plastic.
Other gases
When the plastic has been treated, particularly by flame, it is preferred that it be used as soon as possible, preferably within a day or days of treatment, or that the treated plastic be kept out of contact with freely flowing air or sunlight until used. With plasma treatment, it is found that the a longer lasting activated particle surface results. As such, plasma treated particles can be stored in bulk for from several weeks to several months without substantial degradation of the activated state of the particle surfaces. Nonetheless, use of the treated particles of plastic material as soon after treatment as possible is preferred.
Use of the plastic to produce an asphaltic pavement layer preferably involves the step of blending (75) the plastic particles with rock aggregate and with asphaltic mix binder in a manner that is conventional for the formulation of asphaltic paving material for road surfaces (FIG. 1), with the plastic particles being added as an alternative or supplement to the rock aggregate in the overall mix. The plastic particles function more as the rock aggregate component of the asphaltic concrete than as the asphaltic binder. Only a minor or incidental portion of the plastic, particularly that which is lower density and lower melting point that might remain in the plastic material bulk, would soften and tend to blend with the asphaltic component. Instead, in the preferred embodiment of the invention, the plastic particles supplement the mid-size rock aggregate components. The percentage of the mid-size particles of the rock aggregate may be reduced in the mix, although that is usually not necessary.
Rather than blending a mixture of the treated plastic, binder and rock aggregate, the present invention also provides its advantages when used as a mixture of plastic with asphaltic or oil based binder on road bases, or by applying such a mix over a rock aggregate base layer, where the binder and plastic mix flow down into the base
An example of the he road surface produced is illustrated in FIG. 6 and includes an asphaltic layer 10 overlying the base gravel layer 11 to form a roadway 12. The asphaltic layer 10 may not be the top layer of the roadway 12, but the roadway 12 may also include a surface layer 13 overlying the asphaltic layer 10. The asphaltic layer 10, as illustrated in FIG. 7, is formed of an asphalt binder 20 and a rock aggregate 21 having mixed therewith at least five percent by volume of plastic particles 22, most of which are no. 10 sieve size or larger. The plastic particles 22 have treated activated surfaces. A major portion, and preferably substantially all, of the plastic particles 22 are of a plastic material composition corresponding to PCCS classes 3 through 7. Preferably, most of the particles 22 of plastic are of a size at least 1/8 inch large, and preferably are of a size less than 3/8 inch large, although smaller and larger size particles may be used. The plastic material preferably includes at least thirty percent recycled plastic from the group consisting of thermoset plastics, PVC, and high density polypropylene and polystyrene.
The particles of plastic are believed to strengthen the paving material by adding a slightly flexible interlocking aggregate component that bonds with the asphaltic binder with a partially chemical molecular bond, developing an increased shear resistance of the paving material. The paving material is also more highly impermeable to water, preventing such water from propagating into the gravel bed or subgrade.
Improved properties of the paving material made in accordance with the method of the present invention are illustrated by the example described above. In that example, the treated plastic particles were tested by blending them into the asphaltic mix (using asphaltic concrete 4.4% Navajo 60/70 asphalt cement) that was first heated to a temperature of 265° F. then mixed with the plastic at room temperature. The mixing temperature is preferably that which produces an asphalt cement viscosity of 170+/-20 centistokes kinematic. The plastic was added to the asphaltic mix at a ratio of ten percent by volume, determined from the loose unit weights of the plastic and asphaltic mix. The material was tested by placing it in molds and compacting it to seventy-five blows per side at approximately 250° F. For comparison, other samples were similarly prepared, one sample using the standard asphaltic concrete mix without plastic, and two samples using untreated plastic of the same composition, one added at five percent by volume to the asphaltic mix and one added at ten percent by volume to the mix. The loose unit densities of the components of the mix for the tests were 1.45 grams per cubic centimeter (90.5 pounds per cubic foot) for the asphaltic concrete mix and 0.36 grams per cubic centimeter (22.2 pounds per cubic foot) for the treated and untreated plastic. The five percent by volume of plastic mixes included 1135.88 grams (2.5 pounds) of asphaltic concrete mix and 14.67 grams (0.032 pounds) of plastic, and the ten percent by volume of plastic mixes included 1076.10 grams (2.370 pounds) of asphaltic concrete mix and 39.69 grams (0.065 pounds) of plastic. The tests performed as set forth below and the component analysis as set forth above employed the standards set forth in Table 2:
TABLE 2______________________________________Extraction ASTM D-2172Sieve Analysis ASTM C-136Bulk Unit Weight ASTM D-2726Rice Unit Weight ASTM D-2041Marshall Flow/Stability ASTM D-1559______________________________________
The results of the test were as follows, as set forth in Table 3:
TABLE 3______________________________________Marshall Properties of Asphaltic Concrete 10% 20% No plastic 5% untreated untreated treated______________________________________Bulk Unit Wt. 2.366 2.339 2.261 2.272gms/cm.sup.3 (pcf) (147.4) (145.7) (140.9) (141.5)Rice Wt. 2.419 2.396 2.369 2.370gms/cm.sup.3 (pcf) (150.7) (149.3) (147.6) (147.7)Air Voids 2.2 2.4 4.6 4.1Stability 2821 3078 2432 3404poundsFlow 11 12 11 111/100 in______________________________________
The above results can be compared with the NMSHTD stability requirements of 1640 pounds for non-interstate highways and 1800 pounds for interstate highways. It is found from the tests set forth above that, starting with 2821 pound asphaltic concrete (per the test), the strength increased with the addition of untreated plastic to where it had increased by almost ten percent with the addition of 5% untreated plastic particles. However, the strength decreased as the percentage of untreated plastic particles in the mix increased. With the treated plastic, the strength increased with the addition of the plastic, being about 21% higher than the original asphaltic concrete with the addition of ten percent plastic. It is believed that the strength will exceed that of the original asphaltic concrete mix with treated plastic at up to about 25% with optimally treated and optimally sized plastic particles. Other properties such as flexibility, water impermeability, crack resistance and durability are also expected to be improved over this range.
Those skilled in the art will appreciate that the application of the present invention is herein are varied, and that the invention is described in preferred embodiments Accordingly, additions and modifications can be made without departing from the principles of the invention. Accordingly, the following is claimed:
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An asphaltic concrete or paving material includes at least 5 percent, and preferably from 5 to 20 percent, of granular recycled plastic, which supplements or replaces the rock aggregate component of the mixture. The material produces a structurally superior paving material and longer lived roadbed. The plastic may include any and all residual classes of recyclable plastic, including thermosetting plastics and other plastics having little to no current widespread utility. The material produces roadbeds of higher strength with less total asphalt thickness and having greater water impermeability, and is most useful for all layers below the surface layer. The recyclable plastic component of the material is preferably a mixture of all recyclable classes 3 through 7, or of those materials from such classes from which potentially more valuable recyclable materials have been selectively removed. The paving product is preferably formed by a process of shredding or mechanically granulating used and industrial waste plastic to a no. 4 to 1/2 inch sieve size, and preferably to 1/4 inch to 3/8 inch granules. The granules are then treated with an energized activating medium such as a plasma or a reducing flame, to activate the surface of the granules, preferably without burning or melting the plastic. The activated treated granules are then added to the aggregate and mixed with the asphalt binder to produce the paving material. A slurry or sand mix of plastic and binder may also be applied over an aggregate layer, base layer or roadbed.
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REFERENCES TO RELATED APPLICATIONS
This is a divisional application of U.S. patent application Ser. No. 09/533,397 filed Mar. 22, 2000, now U.S. Pat. No. 6,458,304.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to flash spinning of plexifilamentary film-fibril strands of polyester. This invention also relates to a spin fluid that may be used in existing commercial equipment with minimum changes in the equipment and to a spinning process using existing commercial equipment in which the spinning process utilizes compounds having very low ozone depletion potential, and the compounds are either non-flammable or exhibit very low flammability.
2. Description of the Related Art
U.S. Pat. No. 3,081,519 to Blades and White describes a flash spinning process for producing plexifilamentary film-fibril strands from fiber-forming polymers. A solution of the polymer in a liquid, which is a non-solvent for the polymer at or below its normal boiling point, is extruded at a temperature above the normal boiling point of the liquid and at autogenous or higher pressure into a medium of lower temperature and substantially lower pressure. This flash spinning causes the liquid to vaporize and thereby cool the extrudate which forms a plexifilamentary film-fibril strand of the polymer. Preferred polymers typically include crystalline polyhydrocarbons, such as polyethylene and polypropylene.
According to Blades and White, a suitable liquid for flash spinning (a) has boiling point that is at least 25° C. below the melting point of the polymer; (b) is substantially unreactive with the polymer at the extrusion temperature; (c) should be a solvent for the polymer under the pressure and temperature set forth in the patent (i.e., these extrusion temperatures and pressures are respectively in the ranges of 165 to 225° C. and about 500 to 1500 psia (3447-10342 kPa)); (d) should dissolve less than 1% of the polymer at or below its normal boiling point; and (e) should form a solution that will undergo rapid phase separation upon extrusion to form a polymer phase that contains insufficient solvent to plasticize the polymer.
Commercial flashspun products have been made primarily from polyethylene plexifilamentary film-fibril strands and have typically been produced using trichlorofluoromethane as a spin agent. However, it would be desirable to make flashspun products from other types of polymers, such as polyesters, for example that have different properties than polyethylene.
Flash spinning of some types of polyester is known. U.S. Pat. No. 3,401,140 to Blades et al. discloses 10-80 weight percent of poly(ethylene terephthalate) in methylene chloride or in a mixture of methylene chloride and a perhaloalkane. U.S. Pat. No. 3,227,784 to Blades discloses poly(ethylene terephthalate) in mixtures of methylene chloride with cyclohexane, dichloro-difluoromethane, or dichloro-tetrafluoroethane.
Japanese Patent Publication J06257012, Sep. 13, 1994, discloses that a highly fibrillated network of fibers can be made of poly(ethylene terephthalate). The poly(ethylene terephthalate) may be present at 5-30% weight percent and flashspun from methylene chloride. The reference also states that poly(1,4-butylene terephthalate) can be used to make such fiber networks, but does not provide any details beyond the bare disclosure.
International Patent Publication WO 97/25459 (Jul. 17, 1997) assigned to E. I. du Pont de Nemours and Company (DuPont) is directed to plexifilamentary strands of various polyester blends, for example, poly(1,4-butylene terephthalate) (4GT) with poly(ethylene terephthalate) (2GT) and 4GT with poly(1,3-propylene terephthalate)(3GT). Poly(1,3-propylene terephthalate) may also be referred to as poly(trimethylene terephthalate). The reference also discloses plexifilamentary strands of polyester blended with various other polymers as well as 100% 4GT. The flash spinning was done using either a mixture of CO 2 and water or solvents such as methylene chloride mixed with decafluoropentane (HFC-4310mee).
Microcellular and ultramicrocellular foams of 2GT are disclosed in U.S. Pat. No. 3,227,664 to Blades; U.S. Pat. No. 3,375,211 to Parrish; and U.S. Pat. No. 5,254,400 to Bonner et al., all assigned to DuPont. The solvents used were methylene chloride or mixtures of methylene chloride and dichloro-difluoromethane.
SUMMARY OF THE INVENTION
The invention includes a process for the preparation of plexifilamentary film-fibril strands of synthetic fiber-forming polymer which comprises flash spinning synthetic fiber-forming polyesters of poly(1,3-propylene terephthalate), copolymers of poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate) and copolymers of poly(1,4-butylene terephthalate). Spin agents that can be used include 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,2-dichloroethylene; and dichloromethane.
The invention includes a spin fluid comprising polyesters of poly(1,3-propylene terephthalate), copolymers of poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate) and copolymers of poly(1,4-butylene terephthalate) and selected spin agents as listed above.
The invention also includes processes for making microcellular and ultramicrocellular foams made from poly(ethylene terephthalate), poly(1,3-propylene terephthalate), or poly(1,4-butylene terephthalate).
The invention further includes processes for making blends of polyethylene with poly(ethylene terephthalate), poly(1,3-propylene terephthalate) or poly(1,4-butylene terephthalate).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the cloud point data for a solution comprised of various weight percentages of 2GT in dichloromethane.
FIG. 2 is a plot of the cloud point data for a solution comprised of 2GT in DCE.
FIG. 3 is a plot of the cloud point data for a solution comprised of various weight percentages of 3GT in HCFC-122.
FIG. 4 is a plot of the cloud point data for a solution comprised of various weight percentages of 4GT in HCFC-122.
FIG. 5 is a plot of the cloud point data for a solution comprised of 20 weight percent of various 3GT copolymers in HCFC-122.
FIG. 6 is a plot of the cloud point data for a solution comprised of 25 weight percent of 26T in dichloroethylene/DCM.
DETAILED DESCRIPTION OF THE INVENTION
Processes for making plexifilamentary products of certain types of polyester are known, however, there are certain processes that have not heretofore been disclosed. As noted above, U.S. Pat. No. 3,081,519 provides a typical process for flash spinning.
The term “plexifilamentary strand”, as used herein, means a strand which is characterized as a three-dimensional integral network of a multitude of thin, ribbon-like, film-fibril elements of random length and with a mean film thickness of less than about 4 micrometers and a median fiber width of less than about 25 micrometers, that are generally coextensively aligned with the longitudinal axis of the strand. In plexifilamentary strands, the film-fibril elements intermittently unite and separate at irregular intervals in various places throughout the length, width and thickness of the strand to form the three-dimensional network.
A polyester polymer particularly useful in making the plexifilamentary strands of the invention is poly(1,3-propylene terephthalate) (3GT polyester). Previously, 3GT had not been readily available because an ingredient used to make it, 1,3-propanediol, was itself difficult to make. Recent developments in the production of 1,3-propanediol have made 3GT more readily available for uses as provided herein. It has been found that certain solvents are particularly suited for making the 3GT plexifilamentary strands of the subject invention, i.e., 1,1,2-trichloro-2,2-difluoroethane (HCFC-122) and isomers thereof, 1,2-dichloroethylene (DCE), dichloromethane (or methylene chloride), and also mixtures of HCFC-122 and dichloromethane and mixtures of DCE and dichloromethane. Dichloromethane is a very good solvent for polyesters and may be used as a primary spin agent or as a co-spin agent with DCE or with HCFC-122 to lower the cloud point pressure of the mixture as may be needed. It should be noted that the 1,2-dichloroethylene can be present in either cis- or trans-form.
Although dichloromethane is a good flash spinning agent for polyesters, it has relatively low dielectric strength (about 45 KV/cm). U.S. Pat. No. 3,851,023 to Brethauer et al. discloses that in the production of plexifilamentary webs it is advantageous to subject the flashspun strands to an electrostatic charge. This helps to keep the web pinned to the transporting belt. As such, it is desirable that the spin agent have an acceptable suitable dielectric strength. Therefore, in a commercial operation the maximum throughput rate obtainable with dichloromethane as a spin agent would be limited. To obtain high throughput rates, it would be necessary to add a co-spin agent which has a high dielectric strength such as DCE (about 105 KV/cm) or HCFC-122 (about 110 KV/cm) so that good electrostatic charging and pinning of the webs onto the belt could be achieved. FIG. 6 shows cloud point curves for 2GT in 100% dichloromethane and for 2GT in 85% dichloromethane primary spin agent with 15% DCE co-spin agent. The figure illustrates, for example, that the use of DCE as a co-spin agent provides conditions suitable to flash spin good plexifilamentary film fibrils.
Also, poly(1,4-butylene terephthalate)(4GT polyester) has been found useful. Solvents suitable for making plexifilamentary strands of 4GT include HCFC-122 and DCE. DCE and HCFC-122 are good spin agents for both 3GT and 4GT and well fibrillated plexifilaments can be obtained by flash spinning at a temperature range of 200-240° C. This is shown by the cloud point curves in FIGS. 3-4, which show various amounts of 3GT and 4GT in HCFC-122.
The polyester is present in the solvent at 5-30 weight percent based on the total weight of the spin fluid when plexifilamentary fibers are prepared. The term spin fluid as used herein means the solution comprising the fiber-forming polymer, the primary spin agent, any co-spin agent that may be present, plus any additives that may be present. The term spin mixture may also be used to refer to the spin fluid. Unless noted otherwise, the term weight percent (wgt. %) as used herein refers to the percentage by weight based on the total weight of the spin fluid. The polyester can also be present in the solvent in the range of 10 to 25 wgt. %. Further, the polyester can be present in the solvent in the range of 20 to 25 wgt. %.
The term “cloud-point pressure” as used herein, means the pressure at which a single phase liquid solution starts to phase separate into a polymer-rich/spin agent-rich two-phase liquid/liquid dispersion. However, at temperatures above the critical point, there cannot be any liquid phase present and therefore a single phase supercritical solution phase separates into a polymer-rich/spin agent-rich, two-phase gaseous dispersion.
Certain blended polymer plexifilamentary fibers have been flash spun from a polymer and a solvent solution using a process as generally described in U.S. Pat. No. 3,227,794 to Anderson et al. The apparatus used for solution flash spinning in the examples below was a laboratory scale batch spinning unit that is described below and also in U.S. Pat. No. 5,147,586 to Shin et al. It is anticipated that in commercial applications, certain of the blended polymer plexifilaments of the invention could be solution flash spun using the apparatus disclosed in U.S. Pat. No. 3,851,023 to Brethauer et al.
It has been found that certain polyesters, e.g., 3GT and also 2T and 4GT, can be blended with polyethylene and flash spun using a suitable spin agent to obtain plexifilamentary fibers having desirable properties. To obtain the desired 3GT blends, a mixture of 5 to 95 wgt. % 3GT and 95 to 5 wgt. % high-density polyethylene, based on the total weight of the blend mixture was used. The 3GT blends of polyester plus polyethylene were flashspun in dichloromethane spin agent and consisted of 20 wgt. % of the spin fluid. Also, blends were made from polyethylene with either 2GT or with 4GT, wherein the polyester and the polyethylene were present in the blend at about 50/50 (wgt/wgt). These blends of the polyester plus polyethylene were flashspun in dichloroethylene spin agent and consisted of about 20 wgt. % of the spin fluid. Either high density or low density polyethylene could be used with the subject blends. It is known that 2GT is practically insoluble in DCE, e.g. the cloud point pressure would be in excess of 4500 psig. Also, 4GT is not particularly soluble in DCE, e.g. the cloud point pressure would be in excess of 2500 psig. As such, it is surprising that well-fibrillated plexifilaments of 2GT or 4GT blended with polyethylene can be obtained with DCE as a spin agent.
Microcellular and ultramicrocellular foams can be obtained by flash spinning and are usually prepared at relatively high polymer concentrations in the spinning solution, i.e., at least 40 wgt. % of 2GT, 3GT or 4GT polyester. The microcellular and ultramicrocellular foams of this invention have densities between 0.005 and 0.50 gm/cc. The cells for microcellular foams are generally of a polyhedral shape and their average cell size is less than about 300 micrometers, preferably less than about 150 micrometers. The cell walls are typically less than about 3 micrometers, preferably less than about 2 micrometers in thickness. The ultramicrocellular foams are typically more uniform and of a smaller size. Typical ultramicrocellular foams have an average cell size of less than 50 micrometers and the cell wall thickness is less than 1 micrometer. Hereafter, for the sake of convenience the term foams is meant to include both microcellular and ultramicrocellular foams.
It is known that 2GT polyester does not typically form acceptable plexifilamentary strands, except with dichloromethane as the spin agent. With other spin agents, such as DCE or HCFC-122, the spin pressure would be too high, e.g., in excess of 5000 psi, when less than 30 wgt. % polymer concentration is used to obtain plexifilaments. However, it has been found that at the higher concentrations of polyester (typically 40 wgt. % or greater) used for flash spinning foams, 2GT is sufficiently soluble in other solvents, such as DCE and HCFC-122, to provide spin fluids which can be flash spun to make foams as shown in FIGS. 2-4. FIG. 1 shows that 2GT in dichloromethane exhibits an acceptable range of cloud points, irrespective of the amount of 2GT.
Foams may be formed at relatively low spinning temperatures; and typical spinning pressures used are above the cloud point pressure. However, foam fibers may be obtained rather than plexifilaments even at spinning pressures slightly below the cloud point pressure of the solution. Spin agents and co-spin agents are the same as those noted above for the plexifilamentary, film-fibril materials. Nucleating agents, such as fumed silica and kaolin, can be added to the spin mixture to facilitate spin agent flashing and to obtain uniform, small-sized cells.
Foams can be obtained in a collapsed form or in a fully or partially inflated form. For many polymer/solvent systems, foams tend to collapse after exiting the spinning orifice as the solvent vapor condenses inside the cells and/or diffuses out of the cells. To obtain low density inflated foams, inflating agents having low boiling temperatures are usually added to the spin fluid. Suitable inflating agents that can be used include partially halogenated hydrocarbons, such as, hydrochlorofluorocarbons and hydrofluorocarbons; perfluorocarbons; and hydrofluoroethers. Other organic solvents and gases having low boiling temperatures can be used. When very low density foams (0.0005-0.1 g/cm 3 ) are desired, as-spun foams can be post-inflated using the procedures described in Blades, Parrish and Bonner.
Foam fibers are normally spun from a round cross section spin orifice. However, an annular die similar to the ones used for blown films can be used to make foam sheets.
It should be noted that the 2GT, 3GT, and 4GT polymers herein are intended to include copolymers with recurring units of up to about 15% monomer as well as homopolymers whether used for making foams or plexifilaments. Moreover, it has been found that the addition of monomers to a homopolymer can decrease the cloud point pressure such that the resulting copolymer can be flash spun at a lower temperature and pressure. This is demonstrated in FIG. 5 which presents cloud point curves for various amounts of monomers added to 3GT. The comonomers added were dimethyl isophathalate (DMI), dodecanedioic acid (DDDA) and adipic acid (AA).
EXAMPLES
Test Methods
In the description above and in the non-limiting examples that follow, the following test methods were employed to determine various reported characteristics and properties. ASTM refers to the American Society of Testing Materials.
The intrinsic viscosity of the 2GT and 3GT polymer samples was measured at 19° C. using a Viscotek Forced Flow Viscometer Model Y-900. The samples were dissolved in 50/50 (wt/wt) trifluoroacetic acid/dichloromethane at room temperature at a polymer concentration of 0.4 g/dl. The viscosity data (dl/g) reported represents correlated intrinsic viscosity values in 60/40 (wt/wt) phenol/1,1,2,2-tetrachloroethane following ASTM D-4603-96.
The denier of the strand was determined from the weight of a 15 cm sample length of strand under a predetermined load.
Tenacity and elongation of the flashspun strand were determined with an Instron tensile-testing machine. The strands were conditioned and tested at 70° F. (21° C.) and 65% relative humidity. The strands were then twisted to 10 turns per inch (about 4 turns per centimeter) and mounted in the jaws of the Instron Tester. A two-inch (5.08 cm) gauge length was used with an initial elongation rate of 4 inches per minute (10.2 centimeters per minute). The tenacity at break is recorded in grams per denier (gpd). The elongation at break is recorded as a percentage of the two-inch gauge length of the sample. Modulus corresponds to the slope of the stress/strain curve and is expressed in units of gpd.
The surface area of the plexifilamentary film-fibril strand product is another measure of the degree and fineness of fibrillation of the flashspun product. Surface area is measured by the BET nitrogen absorption method of S. Brunauer, P. H. Emmett and E. Teller, J. Am. Chem. Soc., V. 60 p 309-319 (1938) and is reported as m 2 /g.
Test Apparatus for Examples 1-41
The apparatus used in the Examples is the spinning apparatus described in U.S. Pat. No. 5,147,586. The apparatus consists of two high-pressure cylindrical chambers, each equipped with a piston which is adapted to apply pressure to the contents of the chamber. The cylinders have an inside diameter of 1.0 inch (2.54 cm) and each has an internal capacity of 50 cubic centimeters. The cylinders are connected to each other at one end through a {fraction (3/32)} inch (0.23 cm) diameter channel and a mixing chamber containing a series of fine mesh screens that act as a static mixer. Mixing is accomplished by forcing the contents of the vessel back and forth between the two cylinders through the static mixer. The pistons are driven by high-pressure water supplied by a hydraulic system. A spinneret assembly with a quick-acting means for opening the orifice is attached to the channel through a tee. The spinneret assembly consists of a lead hole of 0.25 inch (0.63 cm) diameter and about 2.0 inch (5.08 cm) length, and a spinneret orifice with a length and a diameter each measuring 30 mils (0.762 mm). A spinneret orifice with a length and a diameter each measuring 30 mils (0.762 mm) was used for all the examples, except Examples 17 and 19. In Example 17, the spinneret orifice had a length and a diameter each measuring 15 mils (0.381 mm). In Example 19, the spinneret orifice had a length of 30 mils (0.762 mm) and a diameter of 15 mils (0.381 mm).
In the tests reported in Examples 1-20 and 41, the apparatus described above was charged with pellets of a polyester and a spin agent. For Examples 21-40, the apparatus was also charged with high density polyethylene, in addition to the polyester. The high-pressure water was used to drive the pistons to generate a mixing pressure of between 1500 and 4500 psig (10,239-30,717 kPa). The polymer and spin agent were then heated to mixing temperature and held at that temperature for a specified period of time during which the pistons were used to alternately establish a differential pressure of about 50 psi (345 kPa) or higher between the two cylinders so as to repeatedly force the polymer and spin agent through the mixing channel from one cylinder to the other to provide mixing and to effect formation of a spin mixture. The spin mixture temperature was then raised to the final spin temperature, and held there for a time sufficient to equilibrate the temperature, during which time mixing was continued. However, the time was kept as short as possible at the subject temperatures to avoid degradation of the polymer or the spin agent. It should be noted that when a range of temperatures is given for a particular example, the mixing time was measured from the starting temperature indicated until the solution was flash spun. In order to simulate a pressure letdown chamber, the pressure of the spin mixture was reduced to a desired spinning pressure just prior to spinning. This was accomplished by opening a valve between the spin cell and a much larger tank of high-pressure water (“the accumulator”) held at the desired spinning pressure. the spinneret orifice was opened as soon as possible (usually about one to two seconds) after the opening of the valve between the spin cell and the accumulator. This period was intended to simulate the residence time in the letdown chamber of a large-scale spinning apparatus. The resultant flashspun product was collected in a stainless steel open mesh screen basket. The pressure recorded during spinning just before the spinneret was entered as the spin pressure. The pressure was recorded using a computer.
It is noted that pressures may be expressed as psig (pounds per square inch gage) which is approximately 15 psi less than psia (pounds per square inch absolute). The unit psi is considered the same as psia. For converting to SI units, 1 psi=6.9 kPa. When an item of data was not measured or was not available, it is noted in the tables as N.M. or N.A., respectively.
Particularly in the tables that follow, the amount of primary spin agent and co-spin agent may be expressed at times as their percentage by weight of the combined weight of the primary spin agent and the co-spin agent. Weston 619F, a diphosphite thermal stabilizer from GE Specialty Chemicals, was added at 0.1 weight percent, based on total spin agent for each of the following plexifilamentary Examples 1-9 and 19-41. The stabilizer was not added to the foam Examples 10-18 unless so noted. Other ingredients were added as noted.
Examples 1-3
In Examples 1-3, 3GT was flash spun using either HCFC-122 or a mixture of HCFC-122 and dichloromethane as the spin agent. The 3GT polymer was prepared from terephthalic acid and 1,3-propanediol with TYZOR®TPT (tetraisopropyl titanate) as the polycondensation catalyst, using methods known in the art. TYZOR®TPT is available from DuPont. The as-prepared polymer had an intrinsic viscosity of 0.76 dl/g. The polymer was solid phase polymerized at 205° C. under nitrogen to obtain an instrinsic viscosity of 1.53 dl/g.
In Example 1, a spin mixture was prepared containing 20 weight percent of 3GT polymer in HCFC-122 spin agent. Cab-o-sil N70-TS colloidal silica was added as a nucleating agent at 1.0 weight percent, based on polymer weight.
In Examples 2-3, the spin mixture contained 15 weight percent 3GT, based on total spin mixture weight, in a 50/50 (wgt/wgt) mixture of HCFC-122 and dichloromethane.
Plexifilamentary fibers were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. In Example 3, a spin tunnel having a diameter of 200 mils (0.51 cm) and a length of 100 mils (0.25 cm) was used outside of the spinneret. Mechanical properties of the plexifilaments are also reported in Table 1.
Examples 4-5
In Examples 4 and 5, plexifilaments were flash spun from a spin mixture containing 20 weight percent 3GT, based on total weight of the spin mixture, and a spin agent which was either trans-1,2-dichloroethylene (DCE) (Example 4) or a 50/50 (w/w) mixture of DCE and dichloromethane (Example 5). Cab-o-sil N70-TS fumed silica nucleating agent (Cabot Corporation, Boston, Mass.) was also added to each of the spin mixtures at 1.0 weight percent, based on polymer.
The 3GT polymer used in Example 4 had an intrinsic viscosity of 1.70 dl/g and was obtained by solid phase polymerization (205° C., nitrogen) of the as-prepared polymer (0.76 dl/g intrinsic viscosity) described in Examples 1-3 and had an intrinsic viscosity of 1.70 dl/g. The 3GT polymer used in Example 5 was also solid phase polymerized (205° C., nitrogen) from the same starting polymer and had an intrinsic viscosity of 1.87 dl/g.
Plexifilaments having a BET surface area of 4.1 m 2 /g for Example 4 and a surface area of 2.0 m 2 /g for Example 5 were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. Plexifilament mechanical properties are also reported in Table 1.
Example 6
This example demonstrates flash spinning of 3GT using dichloromethane as the spin agent. A spin mixture was prepared containing 25 weight percent of the 3GT polymer described in Examples 1-3.
Plexifilaments having a BET surface area of 9.23 m 2 /g were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. Plexifilament mechanical properties are also reported in Table 1.
TABLE 1
3GT Plexifilamentary Fibers
Mixing
Spinning
Fiber Properties @ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Solvent
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
1
HCFC-122
170-210
32
4500
150
3600
3300
211
40
1064
0.46
82
2.03
2
50/50
180-220
17
3200
250
2400
2250
221
50
580
0.47
100
1.23
HCFC-122/CH 2 Cl 2
3
50/50
180-243
17
3600
250
2950
2800
240
50
542
0.49
68
2.02
HCFC-122/CH 2 Cl 2
4
DCE
190
7
3900
350
3250
2950
196
100
900
0.78
85
nm
5
50/50
190
6
2000
200
1200
1100
190
100
489
1.03
86
2.40
DCE/CH 2 Cl 2
6
CH 2 Cl 2
145-240
25
2800
200
1700
1600
240
100
369
0.94
81
3.27
Example 7
This example demonstrates flash spinning of 4GT plexifilaments using HCFC-122 as the spin agent. The 4GT polymer used was CRASTIN® 6129 4GT, obtained from DuPont. CRASTIN® 4GT has a melt flow rate of 9 g/10 min measured by standard techniques at a temperature of 250° C. with a 2.16 kg weight, and has a melting point of 225° C. The spin mixture contained 15 weight percent 4GT polymer, based on total weight of the spin mixture, in HCFC-122 spin agent.
Plexifilaments were obtained by flash spinning the spin mixtures using the conditions given in Table 2 below. Plexifilament mechanical properties are also reported in Table 2.
Examples 8-9
In Examples 8 and 9, plexifilaments were flash spun from a spin mixture containing weight percent of 4GT as described in Example 7 in a spin agent of DCE.
Plexifilaments were obtained by flash spinning the spin mixtures using the conditions given in Table 2 below. Plexifilament mechanical properties are also reported in Table 2.
TABLE 2
4GT Plexifilamentary Fibers
Mixing
Spinning
Fiber Properties @ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Solvent
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
7
HCFC-122
190-230
5
4000
600
3100
2975
231
100
505
0.99
91
4.23
8
DCE
160-200
15
3200
250
2475
2300
200
20
274
0.80
49
nm
9
DCE
160-223
17
3600
250
2850
2700
219
100
359
1.09
77
3.99
Examples 10-12
These examples demonstrate flash spinning of 3GT foam. The 3GT polymer as described in Examples 1-3, having an intrinsic viscosity of 1.53 dl/g, was used to prepare spin mixtures containing 50 weight percent 3GT. Cab-o-Sil N70-TS colloidal silica was added to each spin mixture at 1.0 weight percent, based on polymer. The spin agents used were dichloromethane, DCE and HCFC-122 for Examples 10, 11, and 12, respectively.
The spin mixtures were flash spun using the conditions shown in Table 3 to obtain acceptable foam fibers.
TABLE 3
Flash Spinning Conditions for 3 GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Spin P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
(psig)
(° C.)
10
CH 2 Cl 2
190
30
1500
800
800
450
191
11
DCE
190
35
1500
1000
775
325
189
12
HCFC-122
205
30
1500
1000
770
260-110
203
Examples 13-16
These examples demonstrate flash spinning of 4GT foams. The 4GT as described in Example 7, was used to prepare spin mixtures containing 50 weight percent 4GT. The spin agents used in Examples 13 and 14 were dichloromethane and DCE, respectively. HCFC-122 was used as the spin agent for Examples 15 and 16. Cab-o-sil N70-TS fumed silica (Cabot Corporation, Boston, Mass.) was added to each spin mixture at 1.0 weight percent, based on polymer. The spin mixtures were flash spun using the conditions shown in Table 4 to obtain acceptable foam fibers.
TABLE 4
Flash Spinning Conditions for 4GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Spin P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
(psig)
(° C.)
13
CH 2 Cl 2
190
30
1500
800
800
350
190
14
DCE
190
20
1500
500
800
275-125
190
15
HCFC-122
190
34
1500
1500
800
250-150
185
16
HCFC-122
190
34
1500
1500
800
150-350
185
Examples 17-18
These examples demonstrate flash spinning of 2GT foams. The 2GT was obtained from DuPont. The 2GT polymer, having an intrinsic viscosity of 0.67 dl/g was solid phase polymerized by heating in nitrogen for 16 hours at 235° C. The solid phase polymerized polymer used in Examples 17 and 18 had an intrinsic viscosity of 1.02 dl/g.
The spin agents used in Examples 17 and 18 were DCE and HCFC-122, respectively. Spin mixtures were prepared containing 50 weight percent 2GT. Weston 619F thermal stabilizer was added to the spin mixture of Example 18 at 0.1 weight percent, based on total spin agent. The spin mixtures were flash spun using the conditions shown in Table 5 to obtain acceptable foam fibers.
TABLE 5
Flash Spinning Conditions for 2GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Spin P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
(psig)
(° C.)
17
DCE
190-240
27
2000
200
1200
900
190
18
HCFC-122
210-255
29
2000
400
1200
800-1125
210
Example 19
This example demonstrates flash spinning of a 3GT copolymer containing isophthalate units. The copolymer was prepared using methods known in the art by polymerizing 1,3-propanediol, dimethyl terephthalate, and dimethyl isophthalate using TYZOR®TPT tetraisopropyl titanate as the polycondensation catalyst. The dimethyl isophthalate was added in an amount equal to 5 mole percent of the total dimethyl terephthalate and dimethyl isophthalate. The as-prepared copolymer (intrinsic viscosity of 0.72 dl/g) was solid phase polymerized under nitrogen at 205° C. to obtain an intrinsic viscosity of 1.69 dl/g.
The spin mixture was prepared containing 20 weight percent of the above-described copolymer in HCFC-122 spin agent. The mixing temperature was 210° C., and the mixing time was 10 minutes at a back pressure of 4000 psig and a pressure differential of 250 psig. The solution was flash spun at 211° C. and a spin pressure of about 3000 psig with an accumulator pressure of 3275 psig. The resulting plexifilaments had a denier of 1032 under 100 grams load, modulus of 2.36 grams per denier, tenacity of 1.17 grams per denier, and a percent elongation of 104%.
Example 20
This example demonstrates flash spinning of a 3GT copolymer containing isophthalate units using dichloromethane as the spin agent. The copolymer was prepared using methods known in the art with dimethyl isophthalate added in an amount equal to 5 mole percent of the total dimethyl terephthalate and dimethyl isophthalate. The copolymer was solid phase polymerized under nitrogen to obtain an intrinsic viscosity of 1.49 dl/g.
A spin mixture was prepared containing 20 weight percent of the 3GT copolymer in dichloromethane spin agent. The mixing temperature was 240° C., and the mixing time was 7 minutes at a back pressure of 3000 psig and a pressure differential of 200 psig. The solution was flash spun at a temperature of 241° C. and a spin pressure of 1650 psig with an accumulator pressure of 1800 psig. The resulting plexifilaments had a denier of 584 under 100 grams load, modulus of 4.24 grams per denier, tenacity of 0.89 grams per denier, and a percent elongation of 102%.
Examples 21-23
These examples demonstrate flash spinning of a polymer blend of 3GT and high density polyethylene using dichloromethane as the spin agent. In each example the dichloromethane was present at 80 wgt. % of the spin mixture and the 3GT/polyethylene blend was present at about 20 wgt. %.
The 3GT polymer described in Examples 1-3, having an intrinsic viscosity of 1.53 dl/g was used in these examples. High density polyethylene having a melt index of 0.75 g/10 min (measured according to ASTM D1238 at 190° C. and 2.16 kg load) and a density of 0.95 g/cm 3 was mixed with 3GT and the dichloromethane spin agent to prepare the spin mixtures. The polyethylene was Alathon®, obtained from Equistar Chemicals LP of Houston, Tex.
The spin mixture of Example 21 contained 30 weight percent 3GT and 70 weight percent high density polyethylene, based on the total weight of the blend.
The spin mixture of Example 22 contained 50 weight percent 3GT and 50 weight percent high density polyethylene, based on the total weight of the blend.
The spin mixture of Example 23 contained 70 weight percent 3GT and 30 weight percent high density polyethylene, based on the total weight of the blend.
The mixing temperature was 225° C., and the mixing time was 20 minutes at a back pressure of 2500 psig and a pressure differential of 250 psig. Spinning conditions and plexifilament properties are given in Table 6.
TABLE 6
Flash Spinning Conditions for 3GT/Polyethylene Blends
Fiber Properties
Spinning
@ 10 tpi
Ex.
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
21
1100
850
223
50
294
3.46
119
3.94
22
900
750
227
50
221
3.51
107
4.4
23
1100
975
224
50
271
1.95
116
2.66
Examples 24-40
These examples demonstrate flash spinning blends of 2GT, 3GT or 4GT and high density polyethylene using dichloroethylene as the spin agent. High density polyethylene having a melt index of 0.75 g/10 min (measured according to ASTM D1238 at 190° C. and 2.16 kg load) and a density of 0.95 g/cm 3 was mixed with polyester and the dichloroethylene spin agent to prepare the spin mixtures. The polyethylene was Alathon®, obtained from Equistar Chemicals LP of Houston, Tex. In each of the examples, the polyester and the polyethylene were present in the blend at 50/50 (wgt/wgt). In each of the examples the dichloroethylene was present at about 80 wgt. % of the total spin mixture and the polyester/polyethylene blend was present at about 20 wgt. %.
The 2GT was as described in Examples 17-18. The 3GT copolymer was described in Example 20 was used in Examples 30-32. The 4GT polymer was CRASTIN® 6129 4GT as first described in Example 7.
Mixing and spinning conditions and resultant plexifilament properties are presented in Table 7, below.
Example 41
The spin mixture was prepared containing 25 weight percent of 2GT in a spin agent of 85/15 (wgt/wgt) dichloromethane/DCE. The 2GT was solid-phase polymerized Crystar® 5005sc 656 with an intrinsic viscosity of 1.3. Crestar® is a registered trademark of and available from DuPont. Mixing was started at 150° C. and continued for 45 minutes, and then raised to 220° C. for a total mixing time of 67 minutes. The mixing pressure was 3000 psig throughout. The solution was flash spun at 221° C. and a spin pressure of about 1625 psig with an accumulator pressure of 1800 psig. The resulting plexifilaments had a denier of 806 under 40 grams load, modulus of 8.8 grams per denier, tenacity of 0.95 grams per denier, and elongation of 80%.
TABLE 7
Flash Spinning Conditions for 2GT, 3GT and 4GT/Polyenthylene Blends
Mixing
Spinning
Fiber Properties @ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Blend
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
24
2GT/PE
220
5
2500
600
1400
1350
220
100
314
2.45
107
8.24
25
2GT/PE
210
5
2500
600
1400
1250
210
40
581
1.46
89
6.77
26
2GT/PE
210
10
2500
600
950
750
211
100
410
3.04
110
13.3
27
2GT/PE
210
10
2500
700
1700
1450
211
100
478
3.04
125
8
28
2GT/PE
210
10
2500
700
1550
1250
210
100
440
2.92
118
8.75
29
2GT/PE
210
10
2500
600
1900
1600
210
100
420
2.44
111
2.26
30
3GT*/PE
230
10
2500
600
1100
975
231
40
202
2.15
96
7.12
31
3GT*/PE
220
5
2500
700
1100
700
219
40
682
0.86
261
2.1
32
3GT*/PE
210
10
2500
600
1100
750
211
40
526
1.03
103
2.91
33
4GT/PE
230
10
2500
700
1100
950
233
40
215
2.11
64
6.7
34
4GT/PE
210
10
2500
700
950
NA
211
40
317
1.87
99
6.23
35
4GT/PE
210
10
2500
700
1400
1250
212
100
327
3.53
101
14.7
36
4GT/PE
210
10
2500
700
1700
1300
210
40
654
2.22
125
6.69
37
4GT/PE
210
10
2500
600
1300
1000
210
40
540
1.92
111
4.89
38
4GT/PE
210
10
2500
700
1500
750
209
40
546
2.31
120
6.24
39
4GT/PE
220
5
2500
700
1100
NA
220
100
284
3.53
111
8.16
40
4GT/PE
210
10
2500
700
1100
750
209
40
413
2.15
109
5.80
*These examples included 5 mole % dimethyl isophthalate.
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A process for producing plexifilamentary or foam products by flash spinning in selected spin agents a polymer from the group consisting of poly (1,3-propylene terephthalate), poly (1,4-butylene terephthalate), and poly(ethylene terephthalate), including their copolymers in which the spin agents have minimal or no ozone-depleting properties.
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CROSS-REFERENCE
This application claims the benefit of U.S. Provisional Application No. 60/569,714 filed May 10, 2004.
GOVERNMENT RIGHTS
This invention was made with government support under NASA Contract No. NAS8-02108. The U.S. government holds certain rights in this invention.
FIELD OF THE INVENTION
The present invention is generally directed to a method and apparatus for removing trace contaminants from a flowstream. In particular, this invention provides an improved adsorption process for spacecraft cabin air quality control. More particularly, this invention provides for an energy efficient, lightweight sorption system for the removal of environmental contaminants in space flight applications.
BACKGROUND OF THE INVENTION
Adsorption methods for removing trace contaminants from a flowstream typically comprise passing the flowstream over or through a sorbent structure. The sorbent structure may be defined by a plurality of pellets or an array of tubes or plates or the like, and such structure typically is positioned within the flowpath of the flowstream to be treated. The sorbent structure may comprise, or be coated with, sorbent particles that adsorb targeted impurities from the flowstream. Although such systems are well known in the art, several problems or shortcomings associated with conventional adsorption methods correspondingly also are well known in the art.
For example, when the sorbent becomes saturated, the sorbent must be regenerated or removed and replaced. Typically, the entire sorbent structure simply is replaced. Preferably, the sorbent structure is regenerable. In some systems, the sorbent structure is removed from the adsorption stream, subjected to a desorption process, and then re-exposed to the adsorption stream. One alternative method is described in U.S. Pat. No. 6,712,878 to Chang, et al., wherein sorbent particles are injected into the flowstream and then the flowstream is passed into contact with the sorbent structures. The saturated sorbent periodically is removed and fresh sorbent again is injected into the flowstream.
Another problem associated with conventional adsorption methods is the efficiency of the adsorption technique employed. Often, the unique characteristics of the targeted impurities and the sorbent itself dictate that the adsorption process operate within a desired temperature range. Several methods are known for raising the temperature of the process including heating the flowstream or the sorbent structure by employing an auxiliary heat source. However, non-uniform heat distribution within a fixed-bed substrate or other sorbent structure negatively impacts the efficiency of the process. In addition, the time it takes for an auxiliary heat source to raise the temperature of the sorbent structure, and thereby raise the temperature of the sorbent and the working fluid, further negatively impacts the efficiency of the process. Moreover, less-complex auxiliary heat sources may not provide the capability to reach and hold a narrow operating temperature range as may be required for the subject adsorption goal. Although more complex auxiliary heating systems may be capable of achieving and holding a narrow operating temperature range in a comparatively short time interval, such devices add considerable weight and cost to the adsorption process.
In addition to conventional applications for adsorption processes, such processes occupy an important niche in spacecraft environmental control and life support systems. Primary applications for adsorption processes exist in the area of cabin air quality control. Since the beginning of crewed space exploration, adsorption processes have been at the forefront for ensuring that cabin air is suitable for the crew to breathe by removing trace chemical contaminants and CO 2 . The ability to remove trace contaminants (e.g. alcohols, ketones, aromatics, halocarbons, and ammonia) from cabin air is a necessary aspect of spacecraft life support systems such as that employed on the International Space Station (“ISS”). Currently, this trace contaminant control system (“TCCS”) requirement is met on the ISS by employing a 50 lb. bed of acid-treated activated carbon, which is not regenerated. Due to its long life (>2 yrs.), the carbon bed is simply replaced periodically. The current CO 2 removal system on the ISS employs two pellet bed canisters of 5A molecular sieve that alternate between regeneration and sorption via heating and exposure to space vacuum.
It is anticipated that adsorption processes will continue to remain at the forefront of spacecraft cabin air quality control technologies. As mission durations increase and exploration goals reach beyond Earth orbit, the need for regenerable adsorption processes becomes paramount. Thus, there is a need in the art for an adsorption process that is capable of regenerably removing trace contaminants from a flowstream in an efficient, cost-effective, and robust manner suitable for conventional applications as well as for aerospace applications. There also is a need in the art for an adsorption process that is capable of regenerably removing CO 2 from a flowstream in an efficient, cost-effective, and robust manner suitable for conventional applications as well as for aerospace applications.
SUMMARY OF THE INVENTION
The present invention provides an energy efficient, lightweight sorption system for removal of environmental contaminants in space flight applications. More particularly, the present invention provides an alternative technology for removing both CO 2 and trace contaminants within a single unit employing a sorption bed comprising ultra-short-channel-length metal meshes coated with zeolite sorbents. The metal meshes further define a means for direct, resistive electrical-heating thereby providing the potential for short regeneration times, reduced power requirement, and net energy savings in comparison to the conventional system. The present invention eliminates the need for a separate trace contaminant control unit resulting in an opportunity for significant weight and volume savings.
It has now been found that zeolites deposited on ultra-short-channel-length metal mesh elements, known as Microlith® and commercially available from Precision Combustion, Inc., located in North Haven, Conn., effectively adsorb a number of the contaminants of interest. The inert Microlith® ultra-short-channel-length metal mesh substrate and the use of a binder during deposition of the zeolites on the mesh substrate results in volumetric sorbent loadings considerably lower than if the adsorbents were used as a packed bed (e.g., the carbon bed currently employed). However, the ability to directly resistively heat the metal mesh support provides for relatively rapid periodic regenerations. Therefore, the weight and volume of the current TCCS may be substantially reduced (by as much as 75 wt %) by use of zeolites supported on Microlith® ultra-short-channel-length metal mesh elements in conjunction with periodic sorbent regeneration.
Since cabin air is fed directly to the TCCS, humidity may have a significant negative impact on the performance of the zeolite sorbents. Drying agents are used to mitigate the effect of humidity on sorbent effectiveness and precede the current carbon dioxide removal assembly (“CDRA”). In one embodiment of the present invention, a Microlith® ultra-short-channel-length metal mesh based TCCS is combined with the CDRA function. The system incorporates the existing desiccant beds located upstream of the current pellet-based CDRA bed. These driers mitigate the negative impact of humidity on the effectiveness of 5A for CO 2 sorption. Locating the Microlith® ultra-short-channel-length metal mesh based TCCS system behind the CO 2 removal bed provides a dry stream to the zeolites used for trace contaminant removal.
In another embodiment of the present invention, the packed bed for CO 2 removal was replaced with a Microlith® ultra-short-channel-length metal mesh supported 5A zeolite sorbent. As with the TCCS, the Microlith® ultra-short-channel-length metal mesh provided considerably lower volumetric sorbent loadings than the 5A pellet bed (approximately 30%). However, resistive heating of the Microlith® ultra-short-channel-length metal mesh support permits faster periodic regenerations. In yet another embodiment of the present invention, successful integration of both the CDRA and TCCS systems based entirely on Microlith® ultra-short-channel-length metal mesh supported sorbents—and similar in size to the current CDRA unit alone—eliminates the current TCCS unit entirely with corresponding weight and volume savings. Depending upon the design and regeneration requirements, the integrated system offers power savings, as well as additional weight savings, versus the current CDRA pellet bed. The current TCCS and CDRA system is illustrated in FIG. 1A and the integrated Microlith® ultra-short-channel-length metal mesh based CDRA/TCCS system is illustrated in FIG. 1B .
Microlith® ultra-short-channel-length metal mesh technology is a novel reactor engineering design concept comprising of a series of ultra-short-channel-length, low thermal mass metal monoliths that replaces the long channels of a conventional monolith. Microlith® ultra-short-channel-length metal mesh design promotes the packing of more active area into a small volume, providing increased adsorption area for a given pressure drop. The advantages of employing Microlith® ultra-short-channel-length metal mesh as a substrate include the feature of electrically heating the substrate to promote a reaction on a fluid flowing therethrough as described in U.S. Pat. No. 6,328,936 to Roychoudhury, et al., incorporated in its entirety herein. Whereas in a conventional honeycomb monolith, a fully developed boundary layer is present over a considerable length of the device, the ultra short channel length characteristic of the Microlith® substrate avoids boundary layer buildup. Since heat and mass transfer coefficients depend on the boundary layer thickness, avoiding boundary layer buildup enhances transport properties. The advantages of employing Microlith® ultra-short-channel-length metal mesh as a substrate to control and limit the development of a boundary layer of a fluid passing therethrough is described in U.S. patent application Ser. No. 10/832,055 which is a Continuation-In-Part of U.S. Pat. No. 6,746,657 to Castaldi, both incorporated in their entirety herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A provides a schematic representation of the current TCCS and CDRA system employed on the ISS.
FIG. 1B provides a schematic representation of the integrated Microlith® ultra-short-channel-length metal mesh based CDRA/TCCS system of the present invention.
FIG. 2 provides an isometric view of a simplified Microlith® ultra-short-channel-length metal mesh based radial flow sorber configuration of the present invention.
FIG. 3A provides a schematic representation of an external view of a Microlith® ultra-short-channel-length metal mesh based radial flow sorber configuration of the present invention.
FIG. 3B provides a schematic representation of an internal view of a Microlith® ultra-short-channel-length metal mesh based radial flow sorber configuration of the present invention.
FIG. 4 provides an isometric view of a radial flow reactor configuration of the present invention.
FIG. 5 provides a graphical depiction of durability data of an adsorption system according to the present invention.
FIG. 6 provides a graphical depiction of test data comprising cycle-to-cycle variations in CO 2 sorption of an adsorption system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A provides a diagram of the system currently employed on the ISS. The dehumidification and CO 2 adsorption beds operate in swing mode. A separate charcoal bed for adsorption of TCCS also is shown. FIG. 1B provides a diagram of an embodiment of the present invention. The charcoal bed is eliminated and replaced with a regenerable CO 2 and TCCS adsorption bed which also may operate in swing mode.
One preferred embodiment of the present invention, as shown in FIG. 2 , comprises an axial flow coiled sorber substrate configuration 10 , commonly referred to as a “jelly-roll”configuration, defined by a coiled Microlith® ultra-short-channel-length metal mesh 12 . Unlike its axial flow counterpart, bypassing of the flowstream around the sorber substrate is not a concern in the radial flow configuration. In addition, the radial flow arrangement provides volumetric sorbent loadings at least comparable to a linear bank of screen elements. Furthermore, from the electrical and hardware assembly vantage points, a continuous length of coated screen largely mitigates the complicating issues encountered with a stack of screens. However, employing a stack of screens as an adsorption bed is considered within the scope of this invention.
In a preferred embodiment of the radial flow configuration of the present invention, as shown in FIG. 4 , the sorbent structure 14 comprises a two layer “sandwich” system consisting of a sorbent-coated glass fiber insulating layer 16 and a sorbent-coated Microlith® ultra-short-channel-length metal mesh layer 18 (total coated thickness of the combined layers is approximately 0.1 cm). For dual function CO 2 removal/TCCS, the appropriate lengths of the glass fiber insulating layer and Microlith® ultra-short-channel-length metal mesh layer are coated with the desired amounts of the preferred sorbents 20 . The resultant dual layer system is coiled around a centerline feed supply tube 22 as shown in FIG. 2 . Direct electrical heating of the Microlith® ultra-short-channel-length metal mesh layer in order to regenerate the sorbent is implemented more readily in this arrangement through electrical leads 24 and 26 . However, a radial flow configuration comprising only one layer of a sorbent-coated Microlith® ultra-short-channel-length metal mesh also is considered within the scope of the invention, wherein the coating positioned on the metal mesh serves as the insulating layer between metal mesh layers. Multi-layered radial flow configurations comprising any number of uncoated or sorbent-coated Microlith® ultra-short-channel-length metal mesh layers, with or without any number of uncoated or sorbent-coated glass fiber insulating layers, also are considered within the scope of the invention. The length of the coil or substrate configuration may be selected in order to advantageously employ an available source of electrical current.
As shown in FIG. 3A and FIG. 3B , one embodiment of an adsorption unit 30 according to the present invention comprises a dual-layer sorber coil 32 that defines a diameter of approximately 7.4 inches and a length of approximately 7.2 inches, the centerline of which is occupied by feed tube 34 defining a diameter of approximately 3 inches. Perforated metal tube 36 is positioned between feed tube 34 and sorber coil 32 for support and flow distribution purposes. Sorber coil 32 is fixed within housing 38 by any conventional means such as threaded fasteners 40 , tie rods or the like. Sorber coil 32 and housing 38 are positioned within the adsorption unit casing 42 , which casing 42 defines a plurality of apertures 44 in order to provide access for electrical connections 46 or for a variety of testing and measurement components, such as, for example, a port 48 for air quality testing. Adsorption unit 30 further defines exit tube 50 , inlet plate 52 , and flanges 54 and 56 . Adsorption unit casing 42 is joined to inlet plate 52 by any conventional means such as welding, brazing, threaded fasteners, tie rods, or the like. Alternatively, the adsorption unit casing may be fabricated to comprise a front face such that an inlet plate is not required. Flanges 54 and 56 are application dependent and enable installation of adsorption unit 30 into a system assembly.
This embodiment of the present invention is targeted to operate at approximately the same nominal contact time as the current CDRA sorber (approximately 1.8 seconds). This corresponds to a volumetric flow rate of approximately 5 cfm through the annular sorber coil volume of 258.5 in 3 (4235 cc). Average sorbent loading (based on 5A, Y, and ZSM-5) on the coated coil was 70 mg/in 2 of washcoat (70% zeolite and 30% binder) on each layer (i.e., Microlith® ultra-short-channel-length metal mesh layers and woven glass fiber mesh layers).
The sorber coil 32 plus the 3-inch centerline feed tube 34 occupied approximately 5075 cc, or approximately 30% of the sorbent volume in one of the canisters employed in the current CDRA. The coated sorber coil 32 itself occupied approximately 26% of the current CDRA sorbent volume. Deducting the feed tube volume of approximately 840 cc resulted in a net volume for the total sorber coil (CO 2 & trace contaminant removal) of approximately 4235 cc. Devoting 82.5% of this net sorber volume to CO 2 sorption corresponded to 213.2 in 3 (3494 cc) of sorber volume containing 5284 in 2 at 140 mg 5A sieve/in (70 mg 5A sieve/in/double layer) or 740 gm of 5A washcoat.
The CO 2 sorber regeneration requirement sets the cycle time for the TCCS sorption section of the coil, which occupied 17.5% of the total annular sorption volume, or 45.1 in 3 (740 cc). The TCCS coating followed the 5A coating and therefore was located at the end of the screen, i.e. at the outer portion of the wound coil. The initial 57.5% of this TCCS segment was washcoated with zeolite Y and the balance with ZSM-5. A length/loading calculation similar to that described for 5A sieve above indicated that the TCCS segment contained approximately 90 grams of Y and approximately 67 grams of ZSM-5. Assuming no contribution to trace contaminant removal from the 5A molecular sieve, this allocation of 15–20% of the sorber volume to a post-5A TCCS function (Y/ZSM-5 approximately 1.35) is sufficient to maintain the exit concentration of the trace contaminants below their inlet levels during the sorption cycle.
Power requirements were examined for direct electrical heating of the coil based on estimates of the total energy required to heat the mass of sorber components and to supply the heat of desorption (dominantly that of CO 2 , but also that of the trace components). Radiation losses are ignored since these are likely to be small at the target regeneration temperatures for a well-insulated system having a low ratio of external surface area to total sorber volume. Assuming no other losses, the total required energy during heat up to the regeneration temperature is the sum of mC p ΔT for the washcoat, substrate, and insulating layer plus the heats of desorption (where m=mass; C p =specific heat capacity; and ΔT=temperature difference). The Microlith® ultra-short-channel-length metal mesh sorber coil has a lower bulk density in comparison to a pellet bed of 5A (approximately 65% of the weight of an equivalent pellet volume), and a lower overall estimated specific heat. Assuming a 45 minute sorption/regeneration cycle, approximately 110–150 watts is required per module depending upon the final target regeneration temperature (230–300° C.).
The use of the inert Microlith® ultra-short-channel-length metal mesh substrate to support the zeolite sorbents resulted in a reduced volumetric sorption capacity in comparison to a conventional pellet bed. A preferred embodiment of the present invention employed sorbent comprising 5A zeolite (the calcium form of A) for CO 2 removal, and high Al content zeolite Y (CBV-400), and moderate Al content ZSM-5 (CBV-5524) for trace contaminant removal. The zeolite loadings on the Microlith® ultra-short-channel-length metal mesh substrate should be greater than approximately 20 mg/in 2 , preferably greater than approximately 70 mg/in 2 , and more preferably in the range of approximately 70–100 mg/in 2 .
Bench-scale testing of a stack arrangement for all five of the representative trace components (acetone, dichloromethane, toluene, ethanol, and ammonia) was conducted in order to evaluate the performance of candidate sorbents. The testing ensured that all of the delivered trace contaminant reached the sorbent inlet and could be properly accounted for, despite the particularly challenging ammonia component. An NH 3 /N 2 stream was introduced and mixed with the stream containing the other trace contaminants and/or CO 2 . Ammonia injection and mixing was located just upstream of the sorber section. A mixer was employed to permit uniform flow and mixing across the cross sectional area of the flow path. Analysis of NH 3 in the effluent was conducted via chemiluminescence after catalytically converting it to NO x . The adequacy of system performance was determined in repeated tests employing sampling before and after the empty sorber section, and bypassing the entire system.
Multi-cycle durability testing with both CO 2 and the five trace components also were conducted in order to examine the robustness of the Microlith® ultra-short-channel-length metal mesh supported sorbents. A thermocouple was located in the sorber housing in order to ascertain the mid-bed centerline temperature. To reduce heat losses during regeneration, the sorber housing was removed and subjected to vacuum and external heating within a programmable oven. Bed regeneration temperatures of approximately 230° C. were maintained for approximately 90 minutes after the thermocouple in the center of the bed registered the target value. Thereafter, the oven cooled to room temperature over several hours. Vacuum was maintained on the sorbent housing during the oven cool-down period. Prior to the first sorption cycle, the freshly charged unit was subjected to the modified vacuum regeneration procedure. Regeneration was also conducted after each subsequent sorption cycle.
The reactor design comprising alternate layers of coated Microlith® ultra-short-channel-length metal mesh layers and woven glass fiber mesh, with approximately 80% of the available volume devoted to supporting 5A sorbent for CO 2 removal and approximately 20% devoted to supporting Y and ZSM-5 for trace contaminant removal, was tested for 30 sorption/regeneration cycles over 520 hours to demonstrate durability. The end of a sorption cycle was defined as the point at which any of the delivered feed components closely approached (approximately 98%) its feed concentration. The feed concentrations were approximately ½ SMAC (Spacecraft Maximum Allowable Concentration) for all components with the exception of NH 3 which was delivered at 75%–100% SMAC to facilitate analysis. Results of the 30 cycle durability testing are summarized in Table 1 and graphically represented in FIG. 5 .
TABLE 1
Vacuum
Regeneration
Temp.
Prior to
Relative CO2 Sorp.
ppm Trace Component @ CO2 End of Cycle
Cycle #
Cycle, ° C.
Perfoumance
Ethanol
Acetone
DCM
Toluene
NH 3
1
230
1.00
3
0
0
0
0
5
cycles 1
↓
0.72
4
0
0
0
0
10
through
{open oversize brace}
0.57
5
0
0
0
0
15
15 @ 230 ° C.
0.58
24
0.2
0
0
0
16
275
1.02
47
0.9
0
<0.1
0
17
↓
1.37
52
1
0
<0.1
0
20
cycles 18
230
0.83
74
1.2
0.9
0.1
0
through
{open oversize brace}
↓
22
22 @ 230 ° C.
0.35
65
0.8
0.9
0.1
0
23
275
0.70
88
1.6
1
0.2
0
24
300
1.25
48
0.8
0.2
<0.1
0
25
cycles 25
230
1.15
63
1
1.1
0.1
0
27
through
{open oversize brace}
↓
0.50
80
1.3
1.1
0.1
0
28
28 @ 230° C.
230
—
—
—
—
—
—
29
275
1.22
82
1.4
1.1
0.1
0
The results demonstrate that CO 2 breakthrough defined the end of cycle, i.e. trace contaminants were below their inlet concentration at the point where CO 2 exit concentration approached the inlet concentration. The data in Table 1 illustrates that vacuum regeneration at 230° C. over the first 15 cycles resulted in decreasing CO 2 sorption. Regeneration at mid-bed temperatures above 230° C., however, was able to restore the lost CO 2 sorption capacity, as illustrated by the performance in cycle 16 after a 275° C. regeneration. Back-to-back cycles regenerated at 275° C. exceeded the sorption observed in cycle 1 (1.3× greater CO 2 sorption). This may result from the creation of a cleaner, drier sorbent surface in comparison to that of the fresh sorbent that was subjected to a single milder pretreatment at the 230° C. temperature.
Returning to the 230° C. regeneration temperature for the next 5 cycles (cycles 18 through 22), again resulted in declining cycle-to-cycle performance. Again, back-to-back regenerations at higher temperatures in cycles 23 and 24 (275° C. and 300° C., respectively) resulted in CO 2 sorption 1.25× greater than cycle 1. Finally, performance decline over the next 4 cycles (with regeneration at 230° C.) were once again overcome by back-to-back regenerations at the higher temperatures in cycles 29 and 30 (1.2× and 1.5×greater CO 2 sorption, respectively). These results indicate that the system is robust and suggest that an acceptable operating regimen may employ lower temperature regeneration (i.e. lower power requirement) over several sorption cycles in conjunction with periodic higher temperature regenerations to fully restore bed sorption capacity. Over the 30 cycles, the trace contaminants remained at <25% of their inlet concentrations at end-of-cycle. The exit concentrations increased as the number of cycles increased and showed some variation with regeneration temperature. Overall, however, the data suggested the attainment of an “equilibration” value with increasing number of cycles, which—over the regeneration temperature range employed—was relatively invariant (Runs 20, 23, 27, 29, and 30).
FIG. 6 provides a graphical representation of CO 2 sorption data obtained from a prototype system that was tested with CO 2 and trace contaminants. The data indicates 3 wt % CO 2 co-adsorption capacity and a 45–50 minute cycle during which approximately 55% of the delivered CO 2 was adsorbed. During this test, all trace contaminant levels remained less than or equal to their respective inlet concentrations.
While the present invention has been described in considerable detail, other configurations exhibiting the characteristics taught herein for an improved method for adsorption employing electrically heated ultra-short-channel-length metal mesh elements are contemplated. Therefore, the spirit and scope of the invention should not be limited to the description of the preferred embodiments described herein.
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A method for regenerable adsorption includes providing a substrate that defines at least one layer of ultra short channel length mesh capable of conducting an electrical current therethrough, coating at least a portion of the substrate with a desired sorbent for trace contaminant control or CO 2 sorption, resistively heating the substrate, and passing a flowstream through the substrate and in contact with the sorbent.
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SUMMARY OF THE INVENTION
This invention relates to improvements in adjustable spring loaded agricultural tool mountings, and particularly to means for mounting tools such as chisel plows, cultivator spring teeth and the like.
Heretofore it has been common practice in mounting spring teeth and chisel plows to provide means accommodating change in position of the tool if it encounters obstacles in the ground, such as rocks. Such prior mounting means have been of several types and commonly have utilized double thickness leaf springs or plural coil springs associated with each tool, and have entailed various means for mounting the tool and the springs with respect to the frame of the implement. The use of multiple leaf springs or multiple coil springs associated with each tool has had various disadvantages including difficulty in adjustment of the applied spring pressure for different soil conditions, different depths of soil penetration by the tool, and the like.
It is the primary object of this invention to provide a tool mounting which is readily and quickly adjustable to accommodate variation in applied spring tension and other conditions experienced during use of agricultural implements.
A further object is to provide a device of this character which is simple in construction and inexpensive, and which requires minimum effort to change the adjustment of the tool setting.
Other objects will be apparent from the following specification.
In the drawings:
FIG. 1 is a perspective view of a cultivator embodying my invention.
FIG. 2 is an enlarged perspective view of one embodiment of my adjustable tool mounting.
FIG. 3 is a side view of one embodiment of my adjustable tool mounting with parts shown in section.
FIG. 4 is a side view illustrating the tool in flexed position to pass an obstacle.
FIG. 5 is a side elevational view, with parts shown in section, illustrating a modified embodiment of the invention.
FIG. 6 is a side elevational view illustrating another modified embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and particularly to FIGS. 1-4 which illustrate one embodiment of the invention, the numeral 10 designates an implement of the field cultivator or chisel plow type which has a frame including a plurality of rigid transverse frame members 12 and longitudinal rigid frame members 14. The frame members 12 and 14 are rigidly connected by welding or any other means to provide a rigid frame structure. The frame has suitable draft means 16 for connection to a towing tractor, which draft means may be of any desired type adapted for towing connection with a tractor or for connection with a lift hitch mechanism of a tractor. In the form shown the implement or cultivator is provided with ground wheels 18 journaled on rigid mounting arms 20 projecting downwardly and rearwardly from a transverse rockable member 22 journaled or otherwise rotatable relative to one or more fixed parts of the implement frame by means not shown. The rockable member 22 may be provided with an upstanding arm structure 24 whose position is controlled by any suitable means 26, such as a hydraulic adjustment member, which is extensible and retractable and is connected at one end to the member 24 and at its opposite end to the draft means 16. The setting of the rockable member 22 and of the ground wheels 18 may be utilized to control the working depth of the implement or to provide ground clearance for transport of the implement.
One or more of the transverse frame members 12 have fixedly secured or mounted thereon in spaced relation along the length thereof a plurality of bracket members 30 which preferably are of U-shape in top plan view, being characterized by a transverse vertical plate portion 32 and spaced vertical flanges 34. Each bracket is of a vertical dimension greater than the vertical dimension of the frame member 12 on which it is mounted and projects therebelow. The lower edge of the transverse vertical bracket plate 32 preferably terminates adjacent the bottom of the frame member 12 and the flanges 34 project to a lower level than the bottom of the frame member 12. A transverse pivot pin 36 extends between the flanges 34 at a lower level than the bottom of the transverse frame member 12 and is rearwardly spaced from the member 12.
Bracket members 30 serve to mount pivotally implement tools, such as spring teeth, chisel plows or the like. In the embodiment illustrated in FIG. 2, 3 and 4 the tool includes an elongated member 40 having a downwardly curved part 42 upon the lower end of which may be mounted a ground working member 44, such as a chisel which preferably is removably mounted on the member 40 in fixed position by bolts or other securing means 46. The tool part 40 has fixed or otherwise secured thereto an elongated member 48, such as a plate, which has an arcuate offset portion 50 intermediate its ends which cooperates with the member 40 when positioned in contacting relation therewith to encircle the pivot pin 36 and thereby accommodate rocking of the tool relative to the frame 12 and the mounting bracket 30. The part 50 is spaced from the forward ends of the parts 40 and 48, which parts project forwardly below the mounting frame member 12 and carry spacer means 52 which normally bear against the bottom surface of the frame member 12 as seen in FIG. 3. The spacer means 52 may constitute the head of a bolt or other means which serves to rigidly interconnect the parts 40 and 48. The parts 40 and 48 are preferably in contact for a substantial distance and the part 48 projects rearwardly beyond the offset 50 in divergent relation to the downwardly projecting tool part 42 and preferably terminates in an upwardly bent end portion 56. The member 48, 56 is preferably formed of resilient material to constitute a leaf spring, and preferably has a socket or recess 58, which may be part-spherical, and which is formed in its forward face adjacent the free end thereof.
The means for adjusting the spring loading of the tool may take several forms. That shown in FIGS. 2, 3 and 4 entails a pivot pin 60 journaled in the bracket flanges 34 spaced above and rearwardly relative to the pivot pin 36. Fixed to the pin 60 between the bracket flanges 34 is a shank member 62 to provide a T-shaped member, said shank being screw threaded at 64 and preferably terminating in a reduced diameter end portion 66. An adjustment nut or a pair of such nuts 68 are threaded on the shank portion 64 and a washer 70 preferably bears against the outermost nut. An abutment member 72 has a tubular projecting part 74 whose inner diameter accommodates a snug sliding fit thereof upon the reduced shank part 66 for endwise sliding movement thereon. The abutment member preferably includes a part-spherical head 76 at its opposite end adapted to seat in the socket or recess 58 of the upwardly bent portion 56 of the leaf spring member. The outer diameter of the tubular part 74 is smaller than the adjacent part of the abutment member which provides a shoulder 78 concentric therewith. A coil spring 80 encircles the shank portion 66 and tubular abutment part 74 and bears at its opposite ends upon the washer 70 and the abutment shoulder 78.
In preparing the implement for plowing or cultivating, when the implement is to be supported by wheels 18 while working, the wheel mounting means are adjusted relative to the frame to control the depth at which the ground working tools are to penetrate the soil, and the adjusting nuts 68 of the tools are adjusted or set to control the resistance of the springs to pivoting of the tools from the working position shown in FIG. 3 in which the spacer means 52 abut the adjacent frame member 12. In the construction shown in FIGS. 2, 3 and 4 the latter adjustment is effected by the position of the adjustment nuts upon the shanks 62 which serves to control the compression of the springs 66 and/or the flexure of a leaf spring 48, 56.
As the implement operates to plow or cultivate the soil any obstacle, such as a stone 82, which is encountered by any one or more or the tools causes that tool to be pivoted sufficiently to pass over the obstacle, as shown in FIG. 4. Such pivotal movement entails compression of the spring 80 and/or flexure of the leaf spring 56, or both actions. In the event the coil spring is of lesser strength than the leaf spring 56, initial reaction to pivotal movement of the tool will compress the spring 80 incident to pivotal movement of the shank 62 from its FIG. 3 position toward a position in which said shank is axially aligned with the axes of the pivot pins 36 and 60. When a predetermined amount of free play of tubular part 74 of the abutment member on the shank part 66 causes abutment of the shank 66 with the inner end of the receiving socket of the abutment member 72 any further displacement or pivoting of the tool will result in flexure of the leaf spring part 56 as illustrated in FIG. 4. It will be apparent that the spring tensions of the respective resilient parts may be of any selected values, that the parts are simple in construction, and that adjustments can be effected easily and quickly.
In the modified embodiment of the invention which is illustrated in FIG. 5, parts similar to those in the previously described embodiment bear the same reference numerals. In this construction the shank 62 of the T-shaped pivot pin has its screw threaded portion 64 extending to the end thereof and is received in the complementary internally screw threaded socket part 74' of the abutment member 72' which has its head or end portion 76' received in the socket or recess 58 of the leaf spring member 52, 56. One or more nuts 68 threaded on the shank portion 64 serve as lock nuts when advanced into abutment with the end of the part 74' of the abutment member 72'.
In this construction total reliance for spring action is placed upon the leaf spring 56 which constitutes the single spring associated with the tool mount as distinguished from the dual-spring arrangement of coil spring 80 and leaf spring 56 characterizing the embodiment illustrated in FIGS. 2-4. Spring adjustment is effected by the longitudinal position of the abutment member 72' upon the shank 62 to control the stress applied to maintain the tool in its position illustrated in FIG. 5 wherein the abutment member or spacer 52 bears against the frame member 12 to limit pivoting of the tool in a clockwise direction as viewed in FIG. 5. The positioning of the pivots 36 and 60 relative to the bracket 30 is relied upon to flex the spring 56 as the tool is pivoted about the pin 36 incident to contact of a tool with an obstacle and to ensure that the tool will return to its set or selected working position after the obstacle has been passed.
A third embodiment of the invention is illustrated in FIG. 6 where parts similar to those utilized in the embodiment illustrated in FIGS. 2, 3 and 4 are employed and bear the same reference numerals. The sole difference between the construction shown in FIG. 6 and that shown in FIGS. 2, 3 and 4 is that the upturned end portion 56' of the member 48 is rigidified, as by reinforcing flanges 84, so that said member 56 is no longer a resilient part or leaf spring and the sole resilient part of the tool mount is the coil spring 80, unless the part 42 of the tool possesses spring properties or some resilience.
In each embodiment of the invention the combination of the shank 62 and the abutment member 72 or 72' constitutes a strut which is pivoted at 76 above and rearwardly of the pivot 36 for the tool so that pivoting of the tool as occurs upon encountering an obstacle during working so changes its position as to apply to the spring acting to hold the tool in operative working condition an increase in stress proportional to the degree of movement of the tool from its desired operating position, that is, its movement in a counterclockwise direction about the pivot 36 as viewed in FIGS. 2, 3, 4, 5 and 6. It will be seen that in the construction illustrated in FIGS. 2, 3, 4 and 6 and change of the angular position of the strut 62,72 produces compression of the coil spring 80 incident to telescopic action or shortening of the struut 62,72. In the construction illustrated in FIG. 5, a change of the angular position of the strut 62.72' incident to pivoting of the tool about the pivot 36 increases the stress exerted on the tool by the leaf spring 56. In all cases, the amount of spring pressure to be exerted upon the tool to return it from a displaced to a selected working position after encountering and passing an obstacle is selected by adjustment of the position of the nut 68 upon the strut either solely, as in the construction as illustrated in FIGS. 2, 3, 4 and 6, or in conjunction with change of threaded adjustment of the abutment member 74' on the shank 62 in the construction illustrated in FIG. 5.
While the preferred embodiments of the invention have been illustrated and described, it will be understood that changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.
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An adjustable spring loaded agricultural tool mounting accommodating pivotal movement of the tool relative to a normal operative relation to an implement frame when said tool encounters an obstacle. The tool includes a part projecting upwardly and rearwardly from the tool pivot and a longitudinally extensible and adjustable strut is pivoted in upwardly and rearwardly spaced relation to the tool pivot and bears against the upper free end portion of said upwardly and rearwardly extending tool part. At least one of said strut and said upwardly and rearwardly projecting tool part includes a spring portion.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application PCT/SE01/00911 filed Apr. 27, 2001, incorporated herein by reference, which designated inter alia the United States and was published in English under PCT Article 21(2).
FIELD OF THE INVENTION
[0002] The present invention relates to a headbox for delivering a jet of stock to a forming zone in a former for wet-forming a fiber web, and relates more particularly to the mounting of vanes within a slice chamber of a multi-layer headbox via an arrangement that allows each vane to pivot about its attachment to a turbulence generator of the headbox.
BACKGROUND OF THE INVENTION
[0003] In papermaking, a web is formed in a former of the papermaking machine by delivering a jet of papermaking stock from a headbox to a forming zone of the former. A headbox generally comprises a slice having a slice chamber and a slice opening, and a turbulence generator that includes a plurality of turbulence channels that open out into the slice chamber for delivering stock into the slice chamber. Within the slice chamber, the flow of stock is divided into a plurality of separate channels by vanes that are mounted in the slice chamber, each vane typically being mounted to an elongate anchoring element arranged between adjacent rows of turbulence channels of the turbulence generator. The anchoring element typically has a continuous engagement groove that is open towards the slice chamber to facilitate mounting the vane to the anchoring element.
[0004] SE-511 684 C2 describes a multi-layer headbox with vanes that each have a connection bar with a flexible engagement part for pivotable journaling of the vane to an anchoring element that is fixedly arranged between two rows of turbulence channels. The headbox is of the rectilinear type, i.e., at least the intermediary channels extend in line with the turbulence channels. However, the described fastening of the vane directly to the anchoring element is not suitable in the case of a headbox of the angled type, in which all the vanes and channels in the slice chamber extend at an angle to the turbulence channels, as the axis of pivot is located inside the anchoring element such that the pivoting capacity of the vane would be insufficient, and the vane and connection bar are too close to the opening of the turbulence channel. Furthermore, the described fastening is not applicable in the case of an anchoring element having a dovetail-shaped groove for the connection bar.
[0005] Various solutions have been suggested for mounting a vane aligned at an angle to an anchoring element in a turbulence generator. U.S. Pat. No. 4,133,715 describes turbulence vanes that each have a connection bar consisting of a flexible material and having an extended intermediate part and a wedge-shaped engagement part that is received in a dovetail groove. A change in the position of the vane, due to differences in pressure between the two channels separated by the vane, result in corresponding bending of the long intermediate part. Repeated bending results in flexure fatigue in the material and a risk of the intermediate part fracturing. The bending of the intermediate part also causes the vane to be displaced in its plane so that the downstream end of the vane changes its position relative to the slice opening in proportion to the magnitude of the bending of the intermediate part. Such a change in position of the downstream edge is not acceptable in respect of a stock-separating vane in a multi-layer headbox, as it would affect the layers of the jet of stock detrimentally in the proximity of the slice opening.
[0006] WO 98/50625 describes vanes that each have a connection bar made of stainless steel. The connection bar has an extended intermediate part that is curved to retain the vane at an angle to the turbulence channel. The engagement part of the connection bar is dovetail-shaped to co-operate securely with the dovetail groove in the engagement part to provide a rigid joint. It will be appreciated that the vane and the connection bar are subjected to significant and repeated strains when differences in pressure arise between the two channels that are separated by the vane, so that there is a significant risk of a fracture occurring in the vane adjacent to the connection bar and/or in the connection bar, especially at the root of the dovetail-shaped engagement part. The last-mentioned document acknowledges the problem with such a rigid anchoring of the vane and therefore suggests a modified connection bar, the engagement part of which is fashioned with a circular cross section to form a joint so that the vane can pivot. A potential pivoting of the vane results in a change in position of the downstream edge of the vane, which is not acceptable for a stock-separating vane in a multi-layer headbox. However, it will be appreciated, of course, that the pivoting function is lost after a relatively short period of operation, as the circular joint will get wedged and assume a stationary position impervious to pivoting, which wedge locking occurs because of the tensile forces created by the stocks in the vane. Accordingly, the modified connection bar will function in the same unsatisfactory way as the first described connection bar with the rigid dovetail joint.
[0007] When a vane and/or its connection bar with the fastening systems described above has (have) been damaged, there has hitherto been no alternative and better arrangement for the mounting of the vane to reduce the operational disruptions and replacements. This applies particularly to headboxes where the anchoring elements of the turbulence generator are provided with dovetail grooves and the vanes are positioned at an angle relative to the turbulence channels.
[0008] Further suggestions for fastening a vane to a turbulence generator are described in SE-440 924, U.S. Pat. No. 4,617,091, U.S. Pat. No. 4,941,950, and U.S. Pat. No. 5,013,406.
SUMMARY OF THE INVENTION
[0009] The present invention addresses the problems mentioned above and seeks to provide a mounting arrangement for the vanes of the headbox that is simple in its construction and easy to install and which reduces the risk of damage to the vanes and their potential connection bars. The invention offers a simple and reliable way to replace existing fastening systems with a mounting arrangement in accordance with the invention, for instance in connection with re-construction of an already installed headbox. A headbox and mounting arrangement in accordance with the invention includes a slice defining a slice chamber and a slice opening, at least one vane arranged in the slice chamber to divide the flow of stock into at least two separate channels, a turbulence generator defining a plurality of turbulence channels corresponding to the number of channels in the slice chamber, each turbulence channel feeding stock to one of the channels in the slice chamber, the turbulence generator having an anchoring element for each vane, each anchoring element being arranged between adjacent turbulence channels, and a mounting arrangement for mounting each vane to the corresponding anchoring element. The mounting arrangement comprises a coupling element disposed at an upstream end of the vane, and an assembly bar extending along the anchoring element and adapted to receive the coupling element of the vane.
[0010] In accordance with one preferred embodiment of the invention, the headbox, as well as the mounting arrangement, is characterized in that the assembly bar has
[0011] a protrusion that is arranged to be received in the engagement groove of the anchoring element to form a rigid joint and
[0012] a continuous journaling groove that is arranged at a pre-determined distance from the anchoring element and is open towards the vane by way of a side opening, and has opposite pivot surfaces, and that the pivot member of the vane is arranged to be received in the journaling groove to co-operate with its pivot surfaces to form an axis of pivot.
[0013] In accordance with the invention, the method is characterized in that an assembly bar, having a longitudinal protrusion with a cross section adapted to said pre-determined cross section of the engagement groove, is brought into engagement, by way of said protrusion, with the engagement groove of the anchoring element so that a butt, bending resistant joint is formed therebetween, and in that the pivot member of the vane is brought into engagement with an elongate journaling groove in the assembly bar to cooperate with opposite pivot surfaces in the journaling groove to form an axis of pivot, the vane pivoting about the same.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0014] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0015] [0015]FIG. 1 shows schematically parts of a multi-layer headbox with mounting arrangements for its vanes.
[0016] [0016]FIG. 2 shows, in an enlarged view, two vanes with mounting arrangements in accordance with FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
[0018] [0018]FIG. 1 shows schematically a headbox, designed to deliver a three-layer jet of stock into a gap 1 , leading to a forming zone in a twin-wire former of roll type. The twin-wire former has an inner forming wire 2 , a rotatable forming roll 3 , an outer forming wire 4 and a rotatable breast roll 5 .
[0019] The headbox has a turbulence generator, comprising a group of turbulence channels 6 and a slice 7 , arranged downstream of the turbulence channels 6 and containing a chamber 8 which, from its upstream end, converges in the direction of the flow of stock and, at its downstream end, terminates in a slice opening 9 .
[0020] The turbulence channels 6 are arranged in three sections for feeding, for instance, three different stocks into the slice chamber 8 , the lower section and the upper section each having two rows of turbulence channels 6 arranged closely adjacent to each other and the middle section having four such rows of turbulence channels 6 . The rows of turbulence channels 6 extend across the machine direction and adjacent rows of turbulence channels 6 are separated by elongate, steady anchoring elements 10 that extend across the machine direction. The anchoring element 10 has an elongate, continuous engagement groove 11 (see FIG. 2), which is open at its ends turned away from each other and has a side opening 12 , facing the slice chamber 8 . The cross section of the engagement groove 11 is dovetail-shaped. The turbulence channels 6 debouch with their discharge openings 13 directly into the slice chamber 8 , and said anchoring elements 10 are located adjacent to these discharge openings 13 , in level with each other, for instance, as illustrated. The group of turbulence channels 6 is, at its upstream end, connected to a feeding system (not shown), comprising three stock supplies and suitable flow distributors for even distribution of each stock to the rows of turbulence channels 6 in the appurtenant section and for even distribution of the stock within each row of turbulence channels 6 .
[0021] In the embodiment shown, the headbox has eight vanes 14 , dividing the slice chamber 8 into nine converging channels 15 that communicate with the rows of turbulence channels 6 . Two of the vanes 14 constitute stock-separating vanes 14 a , arranged to separate the three stocks from each other and extending at a pre-determined distance out from the slice opening 9 for forming a jet thus consisting of three layers. The stock-separating vanes 14 a also have a turbulence-generating function. The other vanes are solely turbulence vanes 14 b , which have their free ends located inside the slice chamber at a pre-determined distance from the slice opening. The vanes 14 are relatively stiff and can be made of a metal material, usually titanium, or of a plastic material, usually glass- or carbon-fiber-reinforced epoxy plastic. The vanes 14 are sufficiently stiff to sustain different pressures and speeds in the flows of stock. Each vane 14 has a coupling element forming part of an arrangement for detachable mounting of the vane 14 to said anchoring element 10 . The coupling element in the illustrated embodiment comprises a pivot member 16 . In the embodiment shown, the vane 14 comprises an elongate connection bar 17 (see FIG. 2) that is provided with said pivot member 16 , which is in the shape of a rod-like pivot element with a circular cross section. The connection bar 17 , which is made of metal, for instance bronze, is as long as the vane 14 is wide and comprises, in turn, a downstream engagement part 18 , an intermediate part 19 and an upstream pivot-forming engagement part, which thus forms said pivot element 16 . The engagement part 18 is provided with an elongate, through-running groove 20 for receiving the upstream end part of the vane 14 and engagement dowels 21 arranged in the vane 14 for securing the vane 14 and the connection bar 17 to each other seen in the machine direction. The groove 20 is provided with inner support walls 22 for the engagement dowels 21 .
[0022] The dovetail engagement groove 11 of the anchoring element 10 and circular pivot element 16 of the connection bar 17 form parts of said mounting arrangement. In accordance with the present invention, the mounting arrangement further comprises a special assembly bar 23 , extending along the anchoring element 10 . At its upstream end, the assembly bar 23 is designed with a continuous protrusion 24 , having the same dovetail shape as the engagement groove 11 of the anchoring element 10 to be received in the same with good lateral fit, i.e. without play, and to be brought into locking wedge co-operation with the engagement groove 11 with good fit, i.e. without play, between the assembly bar and the anchoring element so that the assembly bar 23 is secured to the anchoring element 10 by forming a tight joint resistant to torsion. Further, the assembly bar 23 has a continuous journaling groove 25 that extends through the downstream end part of the assembly bar 23 and is open at the ends turned away from each other of the assembly bar 23 . The journaling groove 25 has a continuous side opening 26 , facing the slice chamber 8 and, more particularly, the vane 14 . The journaling groove 25 is dimensioned to receive without friction the circular pivot element 16 of the connection bar 17 from the side, across the machine direction, the width of the side opening 26 being smaller than that of the circular pivot element 16 so that the same is retained therein to fix the vane 14 in its longitudinal direction. The intermediate part 19 of the connection bar 17 is of a thickness that is less than the width of the side opening 26 of the journaling groove 25 to allow the vane 14 to pivot via its connection bar 17 . For this purpose, the journaling groove 25 has opposite, curved, concave pivot surfaces 27 , with which the circular pivot element 16 of the vane 14 is in slideable co-operation to form an axis of pivot 28 that is at right angle to the machine direction. The height of the assembly bar 23 , as seen at right angle to the grooved surface 29 of the anchoring element 10 , is chosen so that the distance a of the axis of pivot at right angle to the anchoring element 10 is sufficiently great to locate the vane 14 and its connection bar 17 at a sufficient distance from the discharge opening 13 of the turbulence channel 6 without detrimentally affecting the flow of stock, which is deflected after the discharge opening 13 of the turbulence channel 6 . The width of the assembly bar 23 is chosen so that it acquires sufficient support surface against the surface 29 of the anchoring element 10 to absorb the torque forces arising in the assembly bar 23 .
[0023] The assembly bar 23 is made of a bending resistant material, preferably metal, for instance bronze. The described dimensioning and design of the assembly bar 23 , including choice of material, ensures that it will withstand the high torque it is subjected to during operation, which means that the axis of pivot 28 maintains or substantially maintains its position in relation to the anchoring element 10 , i.e. without being displaced in parallel with the plane of the vane 14 .
[0024] The invention can also be applied in respect of a vane that lacks a connection bar and which instead has a corresponding pivot element fashioned at its upstream edge or a pivot element arranged within its upstream end portion.
[0025] The invention has been described in connection with a multi-layer headbox. Obviously, it can be applied to a single-layer headbox provided with one or several turbulence vanes.
[0026] The invention is particularly applicable in respect of a headbox in which all the vanes form an obtuse angle with the turbulence channels so that the flows of stock change direction when they enter the slice chamber, as illustrated in FIG. 1. However, it is applicable in respect of a rectilinear headbox, in which the turbulence channels and the slice chamber are designed so that no such change of direction occurs or occurs only in respect of the outer vanes.
[0027] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
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A vane is mounted to a turbulence generator in a headbox by a mounting arrangement that includes an assembly bar that is rigidly connected to an anchoring element of the turbulence generator. The anchoring element has an engagement groove of dovetail shape that receives a similarly shaped protrusion on the assembly bar to rigidly mount the assembly bar to the anchoring element. The assembly bar also includes a continuous journaling groove configured to receive a pivot member of the vane to fix the vane to the assembly bar while leaving the vane free to pivot about a pivot axis that extends in the cross-machine direction.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a magnetic recording medium having a flexible non-magnetic film base and a magnetic layer thereon comprising magnetizable particles dispersed in a binder, the magnetic layer containing or being coated with a lubricant consisting of an organosilicon ester.
2. Description of the Prior Art
A magnetic recording medium whether used for audio recording, video recording, or other magnetic recording purposes comes in contact with tape guide members, magnetic heads and the like during use. In the case of a video tape recorder, where high tape velocities are encountered, the tape must have a sufficient wear resistance and a relatively small friction coefficient if it is to run smoothly and steadily for a long time. Magnetic recording tape which has an increased friction coefficient vibrates at the tape guide members and at the magnetic heads during the recording operation or the reproducing operation, so that the recorded signals or the reproduced signals are distorted from the originals. In some cases, a so-called "Q" sound due to vibration of the magnetic recording tape is encountered.
Efforts have been made to overcome the above-described defects and to impart lubricity or smoothness to the magnetic recording tape, but no completely satisfactory lubricant for magnetic recording tapes has yet been obtained. For example, it has been suggested to use lubricants such as a silicone fluid, castor oil, molybdenum disulfide, graphite, higher fatty acids or the like, the lubricant being mixed into a magnetic layer containing a magnetic powder such as gamma ferric oxide and a binder such as polyvinyl chloride. Magnetic recording tapes containing such lubricants exhibit some wear resistance, but not to a sufficient degree. When a large quantity of the lubricant is mixed into the magnetic layer in order to further increase the wear resistance, a so-called "blooming" occurs on the magnetic layer. The blooming results from the lubricating agent exuding on the surface of the magnetic layer and becoming separated therefrom. As a result, the surface of the magnetic recording tape gets rough, and more powder comes off from the magnetic recording layer.
SUMMARY OF THE INVENTION
The present invention provides a magnetic recording medium which has a flexible non-magnetic film base and a magnetic layer thereon comprising magnetizable particles dispersed in a resinous binder, the magnetic layer containing or being coated with an organosilicon ester having the formula:
(RCOO).sub.n Si(CH.sub.3).sub.4-n
where R is a saturated or unsaturated aliphatic group, usually a straight chained aliphatic group having from 7 to 17 carbon atoms, and n is an integer in the range from 1 to 3.
BRIEF DESCRIPTION OF THE DRAWING
The single drawing accompanying this application is a graph showing the relationship between added amounts of the organosilicon ester and the effect on static friction coefficient and the coming-off amount of powder.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The magnetic recording tape of the present invention has superior wear resistance. Its friction coefficient is reduced and the lubricity or smoothness are improved. Accordingly, the magnetic recording tape of the present invention can run smoothly and steadily for a long time.
The organosilicon compound according to the present invention is a fatty acid ester silane having a chemical bond uniting an aliphatic acidic group to a silicon atom, and having a molecular structure which is difficult to crystallize. Accordingly, the melting point of the organosilicon compound is generally low. It has been found that the magnetic recording tape can be improved to reduce blooming and the coming-off of powder by adding such an organosilicon compound into the magnetic layer thereof, and/or by coating the magnetic layer with such an organosilicon compound. Moreover, the surface energy of the magnetic layer is reduced and thereby the smoothness or lubricity of the magnetic recording tape is improved.
It has been found that the number of carbon atoms in the aliphatic group R should be in the range from 7 to 17 since when the number of carbon atoms is less than 7, the friction coefficient of the magnetic recording tape is too large and that blooming occurs and the coming-off of powder of the magnetic layer is increased when the number of carbon atoms is more than 17.
Preferably, from 0.3 to 5 parts by weight of the organosilicon compound are added to 100 parts by weight of the magnetic powder, for example, a gamma ferric oxide. When more than 5 parts of the organosilicon compound are added to the magnetic powder, the strength of the magnetic layer is reduced and the coming-off of powder is increased, although the friction coefficient is reduced. When less than 0.3 parts of the organosilicon compound are added to the magnetic layer, the organosilicon compound does not provide a sufficient lubricity to the magnetic recording tape and the friction coefficient is not sufficiently reduced.
Any conventional ferromagnetic magnetizable powder such as gamma ferric oxide, magnetite, chromium dioxide or iron-cobalt alloys can be used. The binder can be any of the conventionally used binders employed in magnetic rocording tapes such as a vinyl chloride-vinylacetate copolymer resin in combination with a polyurethane resin. The magnetic layer may also include a conventional antistatic agent such as carbon, and a dispersant such as lecithin.
The organosilicon ester of the present invention can be made in a variety of processes. In one, a chlorosilane is reacted with a fatty acid in the presence of a dehydrochlorination agent such as an amine according to the following equation:
(CH.sub.3).sub.2 SiCl.sub.2 + 2RCOOH + 2N(C.sub.2 H.sub.5).sub.3 → (RCOO).sub.2 Si(CH.sub.3).sub.2 + 2(C.sub.2 H.sub.5).sub.3 N.HCl
This reaction produces the organosilicon compound of the purpose at a high yield.
Another method for synthesizing the organosilicon compound involves reacting an alkoxyl silane such as (CH 3 ) 2 Si(OR') 2 , where R' represents an alkyl group such as a methyl group or an ethyl group with a fatty acid in the presence of an acidic or basic catalyst according to the following equation:
(CH.sub.3).sub.2 Si(OR').sub.2 + 2RCOOH → (CH.sub.3).sub.2 Si(OCOR).sub.2 + 2R'OH
there is a tendency of the organosilicon compound to be hydrolyzed by water. However, the organosilicon compound is sufficiently stable in the absence of strong acid or base. When the number of carbon atoms in the fatty acid group is more than 6, the organosilicon compound is more stable. It has been found that the magnetic recording tape prepared according to the invention is sufficiently stable against the water under normal use conditions.
The following specific examples are given to illustrate the invention. In the examples parts are all parts by weight.
EXAMPLE 1______________________________________Ferromagnetic ferric oxide (gamma Fe.sub.2 O.sub.3) powder 100 parts"VAGH" vinylchloride-vinylacetate copolymerresin (Union Carbide) 20 parts"Nipporan-3022" polyurethane resin (NipponPolyurethane Co.) 10 partsCarbon black 0.5 partsLecithin 1.0 part______________________________________
Two parts of each of the organosilicon compounds set forth in and Table 1 were added into the above-described magnetic composition. Samples Nos. 1 to 5 represent instances where R had 7, 9, 13, 17 and 17 carbon atoms in number, respectively, in each case n was equal to 2. The organosilicon compound of sample No. 5 has an unsaturated aliphatic group. Samples Nos. 6, 7 and 8 in Table 1 are provided for comparison with samples Nos. 1 to 5 according to the present invention. In samples Nos. 6, 7 and 8, R had 21, 18 and 6 carbon atoms in number, respectively, and n was equal to 2 in each instance. In Table 1, sample No. 9 which was a methylphenylsilicone fluid which is an example of a conventional lubricant.
The magnetic mixture containing the organosilicon compound was mixed with stirring with 300 parts of a solvent mixture of equal parts by weight of methylethylketone and methylisobutylketone in a ball mill for 24 hours. The resulting mixtures were applied at a thickness of 10 microns onto polyethylene terephthalate films to form magnetic recording tapes. The tapes were tested for static friction coefficient, the amount of coming-off of powder and the "Q" sound. The results of these tests are also shown in Table 1, where methylphenylsilicone oil was used as the reference (Sample No. 9) of which trade mark is KF-54 (manufactured by Shin-Etsu Chem. Co., Ltd. in Japan), having 400 ± 50 cS of the viscosity at 25° C and from 1.06 to 1.08 of the specific gravity.
TABLE 1__________________________________________________________________________ Coming-off of powder,Sample No. Organosilicon compound Static friction coefficient, μ.sub.s micrograms O sound__________________________________________________________________________1 (C.sub.7 H.sub.15 COO).sub.2 Si(CH.sub.3).sub.2 0.205 63 none2 (C.sub.9 H.sub.19 COO).sub.2 Si(CH.sub.3).sub.2 0.194 60 none3 (C.sub.13 H.sub.27 COO).sub.2 Si(CH.sub.3).sub.2 0.185 56 none4 (C.sub.17 H.sub.35 COO).sub.2 Si(CH.sub.3).sub.2 0.230 70 none5 (C.sub.17 H.sub.33 COO).sub.2 Si(CH.sub.3).sub.2 0.250 55 none6 (C.sub.21 H.sub.43 COO).sub.2 Si(CH.sub.3).sub.2 0.265 110 slight7 (C.sub.18 H.sub.37 COO).sub.2 Si(CH.sub.3).sub.2 0.260 100 slight8 (C.sub.6 H.sub.13 COO).sub.2 Si(CH.sub.3).sub.2 0.350 60 consid- erable9 Methylphenylsilicone fluid 0.443 340 consid- (viscosity 400 ±50 cS at erable 25° C, specific gravity 1.06 to 1.08)__________________________________________________________________________
The static friction coefficient was determined in the following manner. The sample magnetic recording tape was placed with its magnetic surface engaging one quarter of the periphery of a brass cylinder. A constant tension was applied to the sample and the tension was measured at the moment the sample started to slip.
The static friction coefficient (μ s ) was calculated from the following equation: ##EQU1## where T 2 was the measured tension at the moment the sample started slipping, and T 1 was the originally applied tension.
The amount of powder coming off was determined by the difference in weight between an abraded sample and a non-abraded sample.
As is apparent from Table 1, the static friction coefficient of the conventional silicone fluid was considerably larger, the Q sound was considerably greater, and the amount of powder coming off was very large. On the other hand, the static friction coefficients of the improved tapes were very small, the Q sound was absent, and the coming-off of powder was very small. The magnetic recording tapes of samples Nos. 1 to 5 ran smoothly and steadily. The wear resistance was greatly improved. In each of samples Nos. 6 and 7 where the number of carbon atoms in the aliphatic group R was more than 17, blooming occurred and the amount of powder coming off was large, although the static friction coefficient was very small. In the case of sample No. 8, where the number of carbon atoms in the group R was less than 7, the static friction coefficient was relatively large, and there was considerable "Q" sound.
EXAMPLE 2
Three additional samples (Nos. 10, 11 and 12) of magnetic tapes were made with organosilicon compounds as shown in Table 2. In sample No. 10, R had 13 carbon atoms, and n was equal to 3. Samples Nos. 11 and 12 were instances where R was 13 and 17, respectively, and n was 1. The magnetic recording tapes of samples Nos. 10 to 12 were produced in the same manner as in Example 1 and similarly tested. Test results are shown in Table 2, and these results were satisfactory in all respects.
TABLE 2__________________________________________________________________________ Coming-off of powder,Sample Organosilicon compound Static friction coefficient, μ.sub.s micrograms Q sound__________________________________________________________________________10 (C.sub.13 H.sub.27 COO).sub.3 SiCH.sub.3 0.265 50 none11 (C.sub.13 H.sub.27 COO)Si(CH.sub.3).sub.3 0.270 65 none12 (C.sub.17 H.sub.35 COO)Si(CH.sub.3).sub.3 0.282 55 none__________________________________________________________________________
EXAMPLE 3
The amount of organosilicon compound used in sample No. 3 was varied within the range of 0 to 6 parts, to form different magnetic recording tapes. The static friction coefficient and the coming-off amount of powder were tested. The results are shown in the drawing.
As apparent from the drawing, both static friction coefficient μ s and the coming-off amount of powder were satisfactorily small at the added amounts, 0.3, 1, 2, 3 and 5 parts, and particularly in the range of from 0.5 to 2.5 parts. There was no Q sound produced. The amount of powder coming off rapidly increased as the amount added amounted to more than 5 parts. When the added amount was less than 0.3 parts, the static friction coefficient was very large.
EXAMPLE 4
Four polyethylene terephthalate films were coated with the magnetic composition of Example 1 but without addition of the organosilicon compounds to form magnetic layers. Then, the magnetic layers were coated with isopropyl alcohol solutions each containing 1% of any one of the organosilicon compounds shown in Table 3 following including conventional silicone fluid to produce samples Nos. 13 to 15, respectively. The results of these tests are shown in Table 3 following, where methylphenylsilicone fluid was used as the reference (Sample No. 16) of which trade mark is KF-54 (manufactured by Shin-Etsu Chem. Co., Ltd. in Japan), having 400 ± 50 cS of the viscosity at 25° C and from 1.06 to 1.08 of the specific gravity.
TABLE 3__________________________________________________________________________ Coming-off of powder,Sample No. Organosilicon compound Static friction coefficient, μ.sub.s micrograms Q sound__________________________________________________________________________13 (C.sub.9 H.sub.19 COO).sub.2 Si(CH.sub.3).sub.2 0.200 50 none14 (C.sub.13 H.sub.27 COO).sub.3 SiCH.sub.3 0.241 50 none15 (C.sub.17 H.sub.33 COO).sub.2 Si(CH.sub.3).sub.2 0.230 60 none16 Methylphenylsilicone fluid 0.482 50 consid- (viscosity 400 ±50 cS at erable 25° C, specific gravity 1.06 to 1.08)__________________________________________________________________________
The data of Table 3 show that substantially the same results were obtained by coating the magnetic layers with the solution of the organosilicon compounds as in the case where the organosilicon compound was contained in the magnetic layer itself, and that the effectiveness of the organosilicon compound in accordance with the present invention was very remarkable in comparison with the conventional methylphenylsilicone fluid.
While specific examples of the invention have been described, it should be understood that various modifications can be made. For example, the aliphatic group R may have a plurality of double bonds. In addition, two or more of the organosilicon compounds as defined herein can be used in the magnetic layer in combination.
From the foregoing, it will be evident that the improved magnetic tape of the present invention has increased wear resistance, a reduced blooming tendency, and is resistant to powder loss. Since the organosilicon compound used in the present invention imparts sufficient lubricity to the magnetic layer, the friction coefficient is greatly reduced and the generation of "Q" sounds is prevented so that the magnetic tape runs steadily.
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A magnetic recording medium including a flexible non-magnetic film base and a magnetic layer thereon consisting of magnetizable particles in a resinous binder, the magnetic layer containing or being coated with an organosilicon lubricant compound having the formula:
(RCOO).sub.n Si(CH.sub.3).sub.4-n
where R is a saturated or unsaturated aliphatic group containing from 7 to 17 carbon atoms and n is an integer in the range from 1 to 3. The friction coefficient and the tendency of the powder to come off from the magnetic layer of the magnetic recording medium are reduced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority benefit from U.S. Provisional Patent Application No. 61/282,922, filed Apr. 22, 2010, which is hereby incorporated in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to alleviating Internet congestion generally and to doing so by predictive traffic steering in particular.
BACKGROUND OF THE INVENTION
[0003] Internet congestion is known. As Internet usage continues to increase, Internet service providers (ISPs) have experienced difficulties providing enough bandwidth to maintain acceptable levels of throughput for all users on a continual basis. One obvious solution is for the ISPs to add infrastructure to increase capacity. However, such infrastructure can be expensive, and rapid growth to keep pace with demand often leads to instability. Furthermore, even if/when an ISP manages to provide sufficient bandwidth most of the time, it may be difficult to do so during peak usage times.
[0004] When an ISP experiences excess demand for bandwidth, the simplest approach is to provide less than the demand. The decision regarding how and/or to whom to deny bandwidth can be either arbitrary or based on a variety of factors including, for example, user profiles, the amount requested, bandwidth quality, physical/logical topologies, etc.
[0005] Another approach is to actively seek to reduce the demand by implementing an external optimization platform (EOP). An EOP optimizes resource usage for a given Internet service. An EOP may use a variety of methods to optimize the video traffic, for example, transcoding and/or transrating. Transcoding includes reformatting the media content to be downloaded via the network to a different, presumably more efficient encoding technique that requires less bandwidth. For example, a media file identified as being in MPEG2 format may be converted to H264 format which requires less bandwidth for transmission while maintaining more or less the same quality.
[0006] “Transrating” entails reducing the total media content bit rate by either manipulating the frame rate, and/or reducing the number of frames without changing the encoding technique. Transrating thus effectively reduces the quality of the media stream. However as with transcoding, the extent to which it is used determines whether the reduction in quality is acceptable and/or even perceived by the end user.
[0007] In a typical EOP implementation, when Internet users attempt to open a session with an Internet service, the session is terminated by an EOP proxy server. For each intercepted Internet session, the proxy server opens a second session opposite an EOP. If the EOP recognizes the session's content as the type of data which it can optimize, then it in turn opens a session opposite the originally intended server and optimizes the received content before forwarding it to the user via the proxy server. If the EOP doesn't recognize the content, the EOP proxy server then opens a session opposite the originally intended server.
[0008] FIG. 1 , to which reference is now made, illustrates an exemplary implementation 50 of a typical video traffic EOP 25 . User PCs 5 attempt to connect with remote application servers (RAS) 30 via Internet 10 . However, EOP proxy server 20 intercepts the connection attempts before they can continue to servers 30 . Accordingly, PCs 5 do not connect directly with servers 30 . Instead, the associated Internet sessions (arrows 8 ) are terminated by proxy server 20 . Proxy server 20 then initiates a new session (arrows 40 ) with EOP 25 on behalf of each terminated session.
[0009] In the embodiment of FIG. 1 , each PC 5 attempts to connect to a remote application server 30 . PC 5 A attempts to connect with video server 30 A; PC 5 B attempts to connect with email server 30 B; and PC 5 C attempts to connect with IM server 30 C. EOP 25 is configured to optimize video sessions. Accordingly, when EOP proxy initiates a session with EOP 25 on behalf of PC 5 A, EOP 25 recognizes the data as “relevant”, i.e. “video traffic” and interacts with video server 30 A to optimize the resulting data session.
[0010] EOP 25 cannot process all the incoming session data from EOP proxy server 20 . For example, as per the embodiment of FIG. 1 , PC 5 B is attempting to connect with email server 30 B and PC 5 C is attempting to connect with IM server 30 C. Accordingly, the sessions (arrows 40 B and C) initiated by proxy server 20 on their behalf do not contain video traffic, and EOP 25 will indicate to EOP proxy server 20 that it will not process their data. After receiving such indication, EOP proxy server will initiate new sessions opposite servers 30 B and C as per the original addressing provided by PCs 5 B and C respectively.
[0011] Another typical implementation of an EOP based solution replaces EOP proxy server 20 with a traffic steering utility comprising deep packet inspection (DPI) functionality. The utility uses the DPI functionality to inspect packets from PCs 5 as they connect directly with servers 30 . When session data is identified as being relevant to an EOP 25 , the traffic steering utility diverts the session to the relevant EOP 25 instead of to the originally addressed server 30 .
SUMMARY OF THE INVENTION
[0012] There is provided, in accordance with a preferred embodiment of the present invention, an Internet steering gateway including a deep packet inspection (DPI) utility to at least ascertain an indication of a destination remote application server (RAS) from a first packet of a data session, an RAS database to at least store an optimization profile for each of a multiplicity of the RASs, and a steering utility to steer the data session to one of at least one external optimization platform (EOP) and a RAS as per the optimization profile associated with the indication.
[0013] Further, in accordance with a preferred embodiment of the present invention, the gateway also includes means to lookup an optimization profile as per the indication.
[0014] Still further, in accordance with a preferred embodiment of the present invention, the optimization profile includes at least an indication if data traffic associated with the RAS is optimizable.
[0015] Additionally, in accordance with a preferred embodiment of the present invention, the optimization profile includes an indication of which EOP to steer the data session to for optimization.
[0016] Moreover, in accordance with a preferred embodiment of the present invention, the at least one EOP is at least two EOPs.
[0017] Further, in accordance with a preferred embodiment of the present invention, the gateway also includes an EOP database to store an EOP profile and address for at least one EOP.
[0018] Still further, in accordance with a preferred embodiment of the present invention, the DPI utility is configurable to inspect multiple the data packets to ascertain whether or not the data session is optimizable.
[0019] Additionally, in accordance with a preferred embodiment of the present invention, the gateway also includes means for associating a the optimizable data session with a the EOP profile in order to determine an appropriate the EOP for the RAS.
[0020] Moreover, in accordance with a preferred embodiment of the present invention,
[0021] the gateway according to claim 1 also includes means for updating the RAS database with the RAS and an associated the optimization profile, where the associated optimization profile comprises at least an indication of a the EOP that is appropriate for customizing the data traffic associated with the RAS.
[0022] Further, in accordance with a preferred embodiment of the present invention, the at least one EOP is positioned internally within the steering gateway.
[0023] There is also provided, in accordance with a preferred embodiment of the present invention, a method for optimizing network service delivery, implementable on an Internet service gateway, the method including: inspecting a first packet of a data session with a deep packet inspection (DPI) utility, identifying a destination address for an RAS from the first packet, looking up the RAS in a RAS database as per the destination address, and for a RAS found in the RAS database, steering the data session in accordance with a profile associated with the RAS.
[0024] Still further, in accordance with a preferred embodiment of the present invention, the steering includes: steering the data session to an EOP in accordance with the profile, where the profile indicates that the data session is optimizable by the EOP.
[0025] Additionally, in accordance with a preferred embodiment of the present invention, the steering includes steering the data session to the destination address, where the profile does not indicate that the data session is optimizable by an EOP.
[0026] Moreover, in accordance with a preferred embodiment of the present invention, the method also includes inspecting a multiplicity of packets from the data session with the DPI utility, determining if the data session is optimizable, and associating the RAS with an appropriate the EOP in the associated profile.
[0027] Further, in accordance with a preferred embodiment of the present invention, the method also includes: adding a record to the RAS database for the RAS, where the RAS was not found by the looking up.
[0028] Still further, in accordance with a preferred embodiment of the present invention, the method also includes initializing the RAS database with a list of known the RASs with their associated the profiles prior to a first operation of the inspecting by the DPI utility.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
[0030] FIG. 1 is a schematic illustration of a prior art implementation of a video traffic external optimization platform (EOP) with an EOP proxy server;
[0031] FIG. 2 is a schematic illustration of a novel predictive Internet traffic steering system, constructed and operative in accordance with a preferred embodiment of the present invention;
[0032] FIG. 3 is a schematic illustration of an exemplary steering gateway for the system of FIG. 2 ; and
[0033] FIG. 4 is a block diagram of a process to be performed by the gateway of FIG. 3 .
[0034] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
DETAILED DESCRIPTION OF THE INVENTION
[0035] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0036] The prior art suffers from many drawbacks. Proxy based EOP implementations do not scale very well. In such an implementation each Internet session is necessarily processed and likely to be terminated by the proxy server. For each such session, the proxy server initially opens a second session opposite the EOP, and possibly a third opposite the originally intended addressee if the EOP cannot process the data. Effectively, the number of sessions in the network more than doubles in a given period of time. The additional resources required for handling the increased number of sessions may negate all or most of the benefit from the bandwidth savings realized by the sessions processed by the EOP. The cost of additional required equipment to provide the required scale of operation may be more expensive than just adding bandwidth. Furthermore, there is a critical limit to the number of instantaneous sessions which can be proxied by commercially available EOP machines.
[0037] DPI aided traffic steering may have an advantage vis-à-vis proxy based solutions in that they do not entail terminating each session in the network. However, it may be necessary for the DPI to analyze several packets to “classify” the associated traffic, i.e. to establish the nature of a session's data. If so, by the time that the session is steered to the EOP, valuable information regarding the requested service may no longer be available to the EOP. As an EOP and/or the relevant application server typically require the information from the first few packets of a data session to properly set up and execute the requested service, instead of being optimized by the EOP, the service may fail altogether.
[0038] Accordingly, in order for a traffic steering DPI based solution to work reliably, the session data must be forwarded starting with the first packet of the session. Applicant has realized that by “decoupling” traffic classification and traffic steering, a background packet inspection process may be used to identify RASs in real time whose data traffic may benefit from EOP based optimization. Accordingly, by accumulating and referencing profiles of historical session data, it may generally be possible to predict whether or not a given data session may be suitable for processing by a given EOP 25 . In such manner, the entire data session, including the first data packet, may be steered towards an EOP 25 for optimization.
[0039] Reference is now made to FIG. 2 which illustrates a novel predictive Internet traffic steering system 100 , constructed and operative in accordance with a preferred embodiment of the present invention. As in the prior art, PCs 5 may attempt to connect with RASs 30 via Internet 10 . However, data sessions 108 pass through steering gateway 200 before continuing to RASs 30 . Steering Gateway 200 may comprise traffic steering utility 210 and DPI utility 220 . Traffic steering utility 210 may be any commercially available or proprietary Internet traffic steering utility such as known in the art.
[0040] In accordance with a preferred embodiment of the present invention, DPI utility 220 may provide deep packet functionality similar to that disclosed in PCT patent application PCT/IL08/000829, entitled “A DPI MATRIX ALLOCATOR”, filed on Jun. 18, 2008, which is assigned to the common assignees of the present invention, and hereby disclosed in its entirety by reference. It will be appreciated, however, that DPI utility 220 may be provided by any commercially available or proprietary deep packet inspection utility such as known in the art.
[0041] DPI utility 220 may inspect the data packets of data sessions 108 as they pass through gateway 200 . Traffic steering utility 210 may rely on input from utility 220 to determine how to steer continuing data sessions 108 ′. If, as may be disclosed hereinbelow, DPI utility 220 may indicate that a given data session 108 may benefit from EOP 25 , utility 210 may steer the associated data session 108 ′ to EOP 25 for processing. If DPI utility 220 may indicate that a data session 108 is not likely to benefit from optimization by EOP 25 , utility 210 may steer continuing data session 108 ′ directly to the originally addressed RAS 30 .
[0042] Reference is now made to FIG. 3 which illustrates an exemplary steering gateway 200 , constructed and operative in accordance with a preferred embodiment of the present invention. As in the embodiment of FIG. 2 , steering gateway 200 may comprise traffic steering utility 210 and DPI utility 220 . Steering gateway may also comprise RAS database 230 . As may discussed in detail hereinbelow, RAS database 230 may comprise a list of some or all RASs 30 accessed by users connecting to Internet 10 via steering gateway 200 . Reference is also made to FIG. 4 which illustrates a block diagram of an exemplary predictive steering process 300 to be executed by steering gateway 200 in accordance with a preferred embodiment of the present invention.
[0043] DPI utility 220 may inspect (step 310 ) RAS addressing information in the first packet of each new data session passing through steering gateway 200 . Such information may typically be in the form of an IP address and/or URL. Steering gateway 200 may lookup (step 320 ) the indicated RAS 30 in RAS database 230 as per the addressing information.
[0044] If both the relevant RAS 30 is found (step 340 ) and the associated profile in database 230 indicates that traffic intended for the RAS is optimizable (step 340 ), steering utility 210 may steer (step 350 ) the data session to an appropriate EOP as per the RAS profile. It will be appreciated that the embodiment of FIG. 2 is exemplary, system 100 may be configured with multiple EOPs 25 associated with a multiplicity of RASs 30 . Accordingly, RAS database 230 may associate one or more EOPs 25 for each RAS 30 associated with optimizable traffic.
[0045] If the RAS is not found (step 330 ) and/or if the associated profile in database 230 indicates that traffic intended for the RAS is not optimizable (step 340 ), steering utility 210 may steer (step 335 ) the data session directly to the originally addressed RAS.
[0046] It will be appreciated that in such manner an EOP 25 may only handle the specific application related traffic for which it may provide optimization services. As opposed to the prior art where an EOP 25 may be expected to process all of the network's traffic, the present invention substantially reduces the percentage of traffic that is processed by an EOP 25 . For example, in an exemplary network video traffic there may be x data sessions of which one tenth may comprise optimizable video sessions. A prior art EOP proxy server 20 may have to handle x incoming data sessions, initiate an additional x sessions to EOP 25 , and then initiate another 0.9x data sessions with RASs 30 for sessions not handled by EOP 25 . Accordingly, in system 50 proxy server 20 may participate in 2.9x sessions and EOP 25 may participate in x. In contrast, as implemented in system 100 , steering gateway 200 may process only x data sessions and EOP 25 may participate in only 0.1x sessions.
[0047] Returning to FIG. 4 , regardless of how the data session may be steered (i.e. whether via step 335 or step 350 ), DPI utility 220 may continue to inspect and analyze (step 360 ) the next several packets of the data session.
[0048] Based on the results of step 360 , steering gateway 200 may update (step 370 ) RAS database 230 . For example, if the indicated RAS 30 was not found in the lookup of step 320 , gateway 200 may add a new record in database 230 with an associated profile per the addressing information of RAS 30 . The profile may then be updated as per the results of step 360 . If the analyzed data appears to be optimizable by an EOP 25 , then the record will be updated with at least one relevant EOP 25 . Accordingly, the next time a data session attempts to connect with the indicated RAS, steering gateway 200 may steer the data session to the relevant EOP 25 instead of directly to the RAS.
[0049] It will be appreciated that in such manner, database 230 may be populated over time based on the historical results of step 360 . It will further be appreciated that system 100 may therefore begin operation in “learning mode” without an initial list of RAS profiles in database 230 . Steering gateway 200 may simply steer all incoming data sessions to their originally addressed RASs 30 until such time as an incoming RAS 30 may be found in database 230 . However, it will also be appreciated that RAS database 230 may be initialized with a list of known RAS profiles prior to the start of operation.
[0050] There may be occasions on which the results of step 370 may not match the associated profile in RAS database 230 . For example, according to the profile, the data associated with the indicated RAS 30 may not be customizable, whereas the results of step 360 may indicate that the data may be customizable. Gateway 200 may be configured to update (step 370 ) RAS database 230 in accordance with the most recent results of step 36 . Alternatively, gateway 200 may be configured wait until the results of step 360 are confirmed one or more additional times before updating database 230 .
[0051] It will be appreciated that the present invention may provide benefit even if a particular EOP 25 may not require proxy functionality, i.e. the EOP functionality does not require any session termination or other proxy like functionality. In the absence of the present invention, the EOP may be required to pre-process every session in the network if it may receive a direct feed of Internet traffic with no steering or filtering. Such pre-processing may likely require an EOP to handle traffic volumes much larger than necessary, thus leading scalability issues.
[0052] It will also be appreciated that system 100 as illustrated in FIG. 2 may be exemplary. System 100 may not be limited to steering for any particular EOP 25 and/or RAS 30 . Furthermore, unlike the prior art, system 100 may be configured to support a multiplicity of different EOPs 25 processing a multiplicity of different types of data traffic.
[0053] It will also be appreciated that steering gateway may comprise an EOP database (not shown) that may store details regarding EOPs 25 recognized by gateway 200 . The EOP database, may, for example, store a usage profile and addressing information for EOPs 25 . Gateway 200 may use the usage profile to identify an appropriate EOP for a customizable data session identified by DPI unit 220 , and steering unit 210 may use the addressing information to steer the data session accordingly.
[0054] In accordance with a preferred embodiment of the present invention, steering gateway 200 may also comprise a load balancing unit (not shown) which may enable steering gateway 200 to distribute traffic among EOPs and RASs in a generally even manner. Some EOPs and/or RASs may be comprised of multiple servers operating in tandem. DPI unit 220 may forward information to the load balancing unit regarding ongoing data sessions with the individual servers components of relevant EPOs and RASs. The load balancing unit may use this information to instruct steering unit 210 in a manner such that the loads on the individual servers are generally even.
[0055] Unless specifically stated otherwise, as apparent from the preceding discussions, it is appreciated that, throughout the specification, discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer, computing system, or similar electronic computing device that manipulates and/or transforms data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices.
[0056] Embodiments of the present invention may include apparatus for performing the operations herein. This apparatus may be specially constructed for the desired purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk, including floppy disks, optical disks, magnetic-optical disks, read-only memories (ROMs), compact disc read-only memories (CD-ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, Flash memory, or any other type of media suitable for storing electronic instructions and capable of being coupled to a computer system bus.
[0057] The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.
[0058] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
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An Internet steering gateway includes a deep packet inspection (DPI) utility for ascertaining an indication of a destination remote application server (RAS) from a first packet of a data session, an RAS database to at least store an optimization profile for each of a multiplicity of the RASs, and a steering utility to steer the data session to one of at least one external optimization platform (EOP) and a RAS as per the optimization profile associated with the indication. A method for optimizing network service delivery, includes inspecting a first packet of a data session with a deep packet inspection (DPI) utility, identifying a destination address for an RAS from the first packet, looking up the RAS in a RAS database as per the destination address; and for a the RAS found in the RAS database, steering the data session in accordance with a profile associated with the RAS.
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FIELD OF THE INVENTION
Example embodiments described herein relate generally fixation of heat sinks to circuit boards and, more specifically, fixation of a heat sink to a SFP/XFP cage mounted on a circuit board.
DESCRIPTION OF RELATED ART
The small form-factor pluggable (SFP) is a standard for compact, hot-pluggable transceivers used for both telecommunication and data communications applications. The ten gigabit small form-factor pluggable (XFP) is a standard for transceivers for high-speed computer network and telecommunication links that use optical fiber. SFP and XFP transceivers are typically inserted into circuit board-mounted receptacles, termed “cages” to retain the SFP and XFP transceivers for connection to components on a circuit board. A transceiver typically generates heat when it is powered and retained in a cage. The SFP and XFP cages are typically constructed of metal and are typically designed to be bezel-mounted to a circuit board, (e.g., an I/O panel) with compliant pins for pressing onto the circuit board.
Heat sinks are typically used to dissipate heat generated by a transceiver retained in a cage. For each transceiver, the heat generated is transmitted through a corresponding cage and a heat sink in contact with the metal cage. Typically, the heat sink is retained in contact with the cage using a spring clip that presses the heat sink in contact with the cage.
An example of a typical arrangement of a heat sink attached to a cage is shown in FIG. 1 , which is an isometric view showing an upper part and a side of a circuit board 104 . In FIG. 1 , a plurality of cages 102 are spaced from each other across the front of the circuit board 104 . Gaps 106 between adjacent cages 102 provide space for spring clips 108 to mount to the sides of the cages 102 . Specifically, along the top edges 110 of the cages 102 are a plurality of holes that receive the spring clips 108 that are each bent to apply a compressive force to press a respective heat sink 112 into contact with a corresponding upper surface 114 of one of the cages 102 .
The arrangement shown in FIG. 1 however requires that each spring clip 108 and/or heat sink 112 extend into the gap 106 between adjacent cages 102 . In order to maximize the density of cages 102 on the board 104 , the dimensions of the gap 106 would have to be made smaller. However, if the gap 106 is made too small, there will not be sufficient space available to dispose the spring clips 108 in the gap 106 .
SUMMARY
The above and other limitations are overcome by an apparatus and a system for a heat sink assembly, and by a procedure for forming a heat sink assembly.
In accordance with one example embodiment herein, the heat sink assembly includes a heat sink having a base and fins extending from the base, and a spring clip disposed on the heat sink between the fins. The spring clip includes a first tab that forms a first angle with respect to the base of the heat sink and includes a second tab that forms a second angle with respect to the base of the heat sink.
In accordance with another example embodiment herein, the system includes a circuit board having one or more cages mounted thereto, where each cage has an upper surface formed with an opening therethrough, and a heat sink assembly mountable on at least a respective one of the cages. The heat sink assembly includes a heat sink having a base and fins extending from the base, and a spring clip disposed on the heat sink between the fins. The spring clip includes a first tab that forms a first angle with respect to the base of the heat sink and includes a second tab that forms a second angle with respect to the base of the heat sink.
In accordance with another example embodiment herein, the procedure includes placing the heat sink assembly on a cage of a circuit board and securing the first and second tabs to the circuit board.
The example embodiments described herein provide for a heat sink attachment to cage such as a transceiver cage (e.g., an SFP/XFP cage) that is space-efficient so that extra spaces need not be provided on a circuit board between adjacent cages for attachment of a heat sink to the cages. Accordingly, the example embodiments described herein permit a higher density of cages on a circuit board than do conventional arrangements.
Additional features and benefits of the exemplary embodiments will become apparent from the detailed description, figures and claims set forth below.
DESCRIPTION OF DRAWINGS
The teachings claimed and/or described herein are further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, wherein:
FIG. 1 shows an isometric view showing an upper part and a side of a circuit board.
FIG. 2 shows an isometric view showing an upper part and side of a circuit board arranged in accordance with an example aspect of the present application.
FIG. 3A shows an isometric view showing an upper part and a side of a heat sink assembly constructed in accordance with an example aspect of the present application.
FIG. 3B shows an exploded view of a portion of the heat sink assembly shown in FIG. 3A .
FIG. 3C shows an exploded view of another portion of the heat sink assembly shown in FIG. 3A .
FIG. 3D shows a section view of the heat sink assembly, taken along section FIG. 3D - FIG. 3D shown in FIG. 3A .
FIG. 4 is an assembly drawing showing a portion of a circuit board constructed in accordance with an example aspect herein, and the heat sink assembly shown in FIG. 3A .
FIG. 5 shows a section view of the circuit hoard and heat sink assembly, taken along section FIG. 5 - FIG. 5 shown in FIG. 4 .
FIG. 6 is an assembly drawing of another heat sink arrangement in accordance with an example aspect herein.
DETAILED DESCRIPTION
Those of ordinary skill in the art will realize in view of this description that the following detailed description of the exemplary embodiments is illustrative only and is not intended to be in any way limiting. Other embodiments will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the exemplary embodiments as illustrated in the accompanying drawings. The same reference numbers will be used throughout the drawings and the following detailed description to refer to the same or like parts.
FIG. 2 shows a circuit board 200 having a plurality of SFP cages 202 and XFP cages 204 arranged along a front edge 206 of the circuit board 200 . In the specific example illustrated, the circuit board 200 has ten SFP cages 202 and two XFP cages 204 . Each of the cages 202 , 204 is open along the front edge 206 of the circuit board 200 in order to receive a module 500 ( FIG. 5 ). Each of the cages 202 , 204 extends diagonally with respect to the front edge 206 toward a rear edge 208 of the circuit board 200 . While the cages 202 , 204 are shown extending diagonally, in other embodiments the cages 202 , 204 can extend at other angles such as perpendicular with the front edge 206 of the circuit board 200 , or at other orientations. Each of the cages 202 , 204 has an upper surface 210 , which is constructed to contact a heat sink 300 ( FIG. 3A ), to be discussed below. The upper surface 210 has at least one opening 212 . In the embodiment shown in FIG. 2 , the cages 202 , 204 include one rectangular opening 212 , which is constructed to align with and receive a portion of the heat sink 300 . The cages 202 , 204 shown in FIG. 2 are arranged so that there is substantially no (or minimal) gap between adjacent cages 202 , 204 .
FIG. 3A shows a view of an upper side of a heat sink assembly 302 that includes heat sink 300 and a spring clip 304 . The heat sink 300 includes a base 306 and a plurality of fins 308 extending upwardly in FIG. 3A from the base 306 . As would be appreciated by those of skill in the art in view hereof, the fins 308 are arranged to conduct heat away from the base 306 and dissipate heat by convection.
The spring clip 304 has a central serpentine portion 310 , a first tab 312 extending from the serpentine portion 310 , and a second tab 314 extending from the serpentine portion 310 . The spring clip 304 is fixed to the heat sink 300 between some of the fins 308 by snap fit connection. As shown in FIGS. 3B and 3C , at two locations on the heat sink 300 , opposite ends of the serpentine portion 310 are respectively snap fit between adjacent fins 308 of the heat sink 300 .
As shown in FIG. 3D , the serpentine portion 310 of the spring clip 304 extends in a plane substantially parallel to the upper surface of the base 306 of the heat sink 300 . In an uncompressed state shown in FIG. 3D , the first tab 312 extends at a first angle θ 1 with respect to the upper surface of the base 306 . The first tab 312 extends from the serpentine portion 310 to a first free end 316 . Also, in an initial, uncompressed state shown in FIG. 3D , the second tab 314 extends at a second angle θ 2 with respect to the upper surface of the base 306 . The second tab 314 extends from the serpentine portion 310 to a second free end 318 which is formed as a u-shaped hook ( FIG. 3A ).
Also, as shown in FIG. 3D , a lower side 320 of the base 306 has a raised section 322 surrounded by a rectangular bezel (not shown). A front edge 328 and a rear edge 330 of the raised section 322 are beveled.
The heat sink 300 is generally formed from a metal, such as aluminum. The spring clip 304 is generally formed from a metal, such as steel, and is resilient so that the first and second tabs 312 and 314 can be compressed downward toward the base 306 of heat sink 300 without any permanent deformation of the spring clip 304 . The arrangement of the spring clip 304 facilitates uniformly transmitting the spring force to the heat sink 300 so that suitable contact pressure is applied between the heat sink 300 and a respective cage 202 , 204 when a module 500 ( FIG. 5 ) is not inserted in the cage 202 , 204 and between the heat sink 300 and the module 500 when the module 500 is inserted in the cage.
Circuit board 200 is shown in FIG. 4 with a front retaining member 402 that extends across the front edge 206 of circuit board 200 . Above (and offset from) each cage 202 , 204 a corresponding hole 404 is formed in the retaining member 402 of circuit board 200 . Each hole 404 in the retaining member 402 is constructed to receive and retain the first free end 316 of the first tab 312 of the spring clip 304 . Rearward of each cage 202 , 204 is a corresponding anchor 406 that is soldered on the circuit board 200 . In the example embodiment shown in FIG. 4 , each anchor 406 extends upwardly from the circuit board 200 and is a u-shaped latch to latch onto the second free end 318 of the second tab 314 . Thus, in the example embodiment shown in FIG. 4 , for each cage 202 , 204 there is at least one corresponding hole 404 in the front retaining member 402 and at least one corresponding anchor 406 in the board 200 .
The heat sink assembly 302 is assembled onto the board 200 as follows, in one example embodiment. The heat sink assembly 302 is oriented over a corresponding one of the cages 202 , 204 so that the first tab 316 extends toward the front edge 206 of the board 200 and the second tab 314 extends toward the rear edge 208 of the board 200 . The first end 316 of the first tab 312 is inserted into a hole 404 in the front retaining member 402 and the raised portion 322 of the heat sink 300 is inserted into the rectangular opening 212 in the cage 202 , 204 corresponding to the hole 404 in which the first end 316 was inserted. The second tab 314 is compressed toward anchor 406 corresponding to the cage 202 / 204 until the second free end 318 latches onto the anchor 406 .
As shown in FIG. 5 , the cages 202 , 204 are constructed to receive a module 500 , which includes electrical and optical modules. When the heat sink assembly 302 is attached to the circuit board 200 and no module 500 is present in a corresponding one of cages 202 , 204 , the spring clip 304 of the heat sink assembly 302 is compressed an initial amount so as to force the bezel of heat sink 300 downwardly to contact the surface 210 of cage 202 , 204 in a seated position. When the heat sink 300 is seated, the raised section 322 of heat sink 300 extends through a respective opening 212 in the corresponding cage 202 , 204 . Thus, when the module 500 is not present in the cage, the raised section 322 extends slightly into cage 202 , 204 .
When the module 500 is first introduced into a respective cage 202 , 204 (as shown in FIG. 5 ), there will be interference between the module 500 and the raised section 322 extending into the respective cage 202 , 204 . Owing to the beveled front edge 328 of the raised section 322 , which acts as a guide surface, when module 500 is first inserted into the respective cage 202 , 204 on which heat sink 300 is seated, module 500 contacts the front edge 328 and displaces the raised section 322 upwardly. As raised section 322 is displaced upwardly, the spring clip 304 is further compressed beyond its initial compression before module 500 was inserted in the cage 202 , 204 . The spring force exerted by the spring clip 304 urges the raised section 322 to contact the module 500 with suitable pressure to promote conductive heat transfer from the module 500 to the heat sink 300 .
The dimensions and positions of the first tab 312 and second tab 314 are such that the torque (Mo(Fa)) exerted on the spring clip 304 by the first tab 312 about point “o” is almost equal and opposite to the torque (Mo(Fb)) exerted on the spring clip 304 by the second tab 314 about point “o”, when the first end 316 is in hole 404 and the second end 318 is latched to anchor 406 . The substantially equal and opposite torques Mo(Fa) and Mo(Fb) permit suitable and even pressure to be applied between raised portion 322 of heat sink 300 and module 500 to enable heat transfer from module 500 to heat sink 300 , which is then convected to air through fins 308 .
The beveled front edge 328 and rear edge 330 shown in FIG. 3D facilitate placement of the heat sink 300 on a respective one of the cages 202 , 204 and facilitate self-seating of the heat sink 300 should the heat sink assembly 302 be displaced at least partially from opening 212 , such as when module 500 is first inserted into a respective cage 202 , 204 .
Also, the raised section 322 is located closer to a front end 324 of the heat sink 300 than it is to a rear end 326 of the heat sink 300 . The off-center raised section 322 further facilitates positioning and alignment of the heat sink assembly 302 with respect to a respective one of cages 202 , 204 by providing a visual indication that the heat sink assembly 302 is oriented properly or improperly with the first tab 312 extending toward the front edge 206 of the circuit board 200 and the second tab 314 extending toward the rear edge 208 of the circuit board 200 , as is shown in FIG. 4 . As but one example of a visual indicator that the heat sink assembly 302 may be improperly oriented, if the raised section 322 is inserted into an opening 212 , and the bezel surrounding the raised section 322 is seated on upper surface 210 of a cage 202 , 204 , and the heat sink assembly 302 is oriented such that the second tab 314 extends towards front edge 206 of circuit board 200 instead of towards the rear edge 208 of circuit board, then the second end 318 will not be positioned relative to the circuit board 200 in a manner to enable it to be attached to the circuit board 200 , as described in detail above.
FIG. 6 shows an alternative example embodiment of a heat sink arrangement of a plurality of heat sink assemblies 602 assembled onto the circuit board 200 . The heat sink assemblies 602 are the same as heat sink assemblies 302 , except that the heat sink 600 included with each heat sink assembly 602 is different than the heat sink 300 included with each heat sink assembly 302 . In particular, in the embodiment shown in FIG. 6 , a retention slot 604 is formed in each heat sink 600 to receive a wall 608 of a metal cover 606 . At least one ventilation opening 612 is formed in the cover 606 . The heat sink assemblies 602 are fixed to the circuit board 200 in the same way as they are for the heat sink assemblies 302 described above. When the heat sink assemblies 602 are fixed to the circuit board 200 , the retention slots 604 of the heat sinks 600 align in a substantially straight line 614 , which is shown being substantially parallel to the front edge 206 of the circuit board 200 . Once the heat sink assemblies 602 are fixed to the circuit board 200 , the wall 608 of the cover 606 is inserted into the aligned retention slot 604 and the cover 606 is secured to the retaining member 402 with screw fasteners 616 .
The metal cover 606 is removably attached to the retaining member 402 with screw fasteners 616 . As shown in FIG. 6 , the cover 606 is not attached to retaining member 402 , but is disposed slightly above retaining member 402 . The cover 606 can be removed to permit the heat sink assemblies 602 to be installed and removed. When the cover 606 is attached to retaining member 402 with the wall 608 disposed in retention slots 604 , the wall 608 limits movement of each heat sink 600 in a front-to-back, longitudinal direction along the upper surface 210 of its corresponding cage 202 , 204 , as well as limits movement in an up-and-down direction. Thus, displacement of the heat sink assemblies 602 caused by, for example, inserting and removing a module 500 ( FIG. 5 ) from a respective cage 202 , 204 , can be limited.
The example embodiments described herein provide for a heat sink attachment to cage such as a transceiver cage (e.g., an SFP/XFP cage) that is space-efficient so that extra spaces need not be provided on a circuit board between adjacent cages for attachment of a heat sink to the cages. Accordingly, the example embodiments described herein permit a higher density of cages on a circuit board than do conventional arrangements.
While particular example embodiments have been shown and described, it will be obvious to those of skills in the art that based upon the teachings herein, changes and modifications may be made to the example embodiments without departing from these embodiments and their broader aspects. Therefore, the appended claims are intended to encompass within their scope all such changes and modifications as are within the true spirit and scope of the exemplary embodiments.
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An apparatus and system for a heat sink assembly, and a procedure for forming a heat sink assembly. The heat sink assembly includes a heat sink having a base and fins extending from the base, and a spring clip disposed on the heat sink between the fins. The spring clip includes a first tab that forms a first angle with respect to the base of the heat sink and including a second tab that forms a second angle with respect to the base of the heat sink. The first and second tabs are attached to the circuit board. By virtue thereof, a heat sink attachment to cage is provided that is space-efficient and permits a higher density of cages on a circuit board than do conventional arrangements.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to storage devices for the delivery and pickup of goods, and more particularly to a storage device that secures goods from theft and exposure to the elements and that provides a notification that goods have been delivered to and/or picked up from the storage device.
2. Description of the Prior Art
Home delivery of goods has become an increasingly popular way for consumers to reduce shopping time. For example, many retail stores allow consumers to order clothes, appliances, furniture and other goods from catalogues for direct delivery to their homes. Similarly, many laundry and dry cleaning businesses pick up and deliver laundry directly to consumers' homes, and many grocery stores deliver groceries directly to consumers' homes.
The recent growth of the Internet has further accelerated this trend towards home delivery. For example, many major retailers such as Wal Mart are developing Internet sites that permit consumers to see three-dimensional images of their goods and order these goods while on-line. The goods are then shipped directly from the manufacturer to the consumer rather than to the retailer.
Home delivery of goods not only saves consumers time and money, but it also has the potential to significantly reduce gas consumption and automobile pollution since consumers won't have to drive to conventional stores to buy and pick up groceries, laundry, clothing and other goods. However, home delivery has not yet gained wide-spread consumer acceptance because there are currently no means to insure safe, convenient, and unobtrusive delivery of the goods.
If consumers currently place orders for the home delivery of goods, they must either (1) be at home when the goods are delivered, (2) make arrangements for the goods to be left at their door unattended or with a neighbor, or (3) provide the vendor or delivery person with keys to their home.
None of these options are satisfactory because they are not safe, convenient, and/or unobtrusive. Particularly, requiring consumers to wait at home for the delivery of their goods or to make arrangements with neighbors is not convenient and therefore defeats the purpose of home delivery. Moreover, even when the consumers are home, they often do not wish to be disturbed by delivery people. Similarly, leaving the goods outside the consumers' homes may result in theft or damage of the goods. Finally, providing vendors with keys raises privacy and security concerns, especially as the number of vendors making home deliveries to a particular home increases. The lack of a convenient delivery means is especially problematic for the home delivery of groceries since groceries often must be promptly refrigerated.
Another problem with home delivery of goods is that consumers are often not notified when the goods are delivered or picked up. For example, if goods are left outside of a consumers' home early in the morning, the consumers often will not see the goods until they return from work in the evening. Leaving the goods unattended for such a long time obviously increases the risks of theft or damage.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide an improved storage device for the delivery and pickup of goods that encourages consumers to take advantage of the benefits of home delivery.
It is a more particular object of the present invention to provide a storage device that protects delivered goods from theft and/or damage.
It is another object of the present invention to provide a storage device that preserves refrigerated food items after they are delivered.
It is another object of the present invention to provide a storage device that notifies the homeowner when goods have been delivered.
It is another object of the present invention to provide a storage device that notifies a vendor that goods are to be picked up once the homeowner places the goods in the storage device.
In view of these objects and other objects that become evident from the description of the preferred embodiments of the invention herein, an improved storage device is disclosed. The storage device broadly includes an enclosure for enclosing delivered goods or goods that are to be picked up and a communication apparatus operably coupled with the enclosure for controlling entry to the enclosure and for providing a notification that goods have been delivered to or picked up from the enclosure.
In more detail, the enclosure includes a door, a lock for locking the door, and a lock operator for unlocking the lock. In preferred forms, the lock operator includes a keypad for permitting the entry of a plurality of keycodes.
The preferred communication apparatus includes a controller coupled with the keypad and lock operator and a transmitting device responsive to the controller. The controller includes conventional memory for storing a plurality of vendor codes each associated with a separate vendor and a plurality of vendor messages each associated with one of the vendor codes.
Each vendor that makes deliveries to the storage device is assigned and notified of a unique vendor code. When a vendor makes a delivery, the vendor enters its vendor code into the keypad. The controller verifies that the entered keycode is accurate and then unlocks the door if it is. The controller also retrieves the vendor message associated with the entered vendor code and directs the transmitting device to transmit the vendor message to a location remote from the storage device for providing a notification that a delivery has been made. In preferred forms, the transmitting device transmits the vendor message to a communication apparatus located in the homeowner's home or business.
The storage device also preferably includes an insulated compartment and a refrigeration unit for cooling the insulated compartment. The controller turns on the refrigeration unit whenever a vendor that delivers frozen or refrigerated items enters its vendor code into the keypad.
By constructing a storage device as described herein, numerous advantages are realized. For example, by constructing a storage device having an enclosure with a door, a lock, a lock operator, and a communication apparatus for controlling the entry to the enclosure, goods can be safely delivered to and/or picked up from he storage device without fear of theft and damage.
Additionally, by constructing a storage device with a communication apparatus that notifies a homeowner when goods have been delivered or notifies a vendor that goods are ready to be picked up, consumers and vendors can more easily monitor deliveries to the storage device and can arrange to remove the goods from or place goods into the storage device.
Additionally, by constructing a storage device with a communication apparatus that stores a plurality of vendor codes and compares entered codes to these stored vendor codes, a plurality of vendors can make deliveries to the storage device, and the communicating apparatus can identify which vendor has made a delivery and provide the homeowner with a unique notification message for each vendor.
Additionally, by constructing a storage device with an insulated compartment and a refrigeration unit for cooling the insulated compartment, refrigerated or frozen food items can be delivered to the storage device and preserved until the homeowner retrieves them from the storage device. Moreover, by coupling the refrigeration unit with the controller, the refrigeration device can be automatically turned on when particular deliveries are made to the storage device.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:
FIG. 1 is a perspective view of a storage device constructed in accordance with a first preferred embodiment of the invention showing the storage device attached to a home;
FIG. 2 is a perspective view of a storage device constructed in accordance with a second embodiment of the invention showing the storage device as a stand-alone unit;
FIG. 3 is a perspective view of the storage device illustrated in FIG. 2 with parts broken away and showing the doors of the storage device open;
FIG. 4 is a section view of the storage device taken along line 4--4 of FIG. 2; and
FIG. 5 is a schematic diagram of the communication apparatus of the storage device shown operably coupled with a plurality of remote communication apparatuses.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The storage device 10 of the present invention may be constructed in accordance with three preferred embodiments. FIG. 1 illustrates a first embodiment of the invention wherein the storage device 10 is configured for attachment to a building such as a home 12 or business. The storage device is attached to the home 12 by conventional attachment hardware such as bolts or brackets. FIGS. 2-4 illustrate a second embodiment of the invention wherein the storage device 10 is configured as a stand-alone unit for placement near the home 12 or business. In a third embodiment of the invention, the storage device is configured for attaching through the wall of a building such as a home or business for permitting access from both sides of the storage device.
All embodiments of the storage device 10 broadly include an enclosure 14 for enclosing delivered goods or goods that are to be picked up and a communication apparatus 16 for controlling access to the enclosure 14 and for providing notification that goods have been delivered to or picked up from the enclosure 14.
In more detail, the enclosure 14 may be constructed of any suitable material such as wood, plastic or metal and is preferably approximately 66" tall, 24-30" wide, and 24" deep. The enclosure may include removable panels in different colors and textures that can be attached to the exterior of the enclosure to permit homeowners to personalize the look of the enclosure or to match the color of the home.
As best illustrated in FIG. 3, the enclosure 14 includes a front hinged door 18 for permitting access to the front of the enclosure 14 and may include a rear hinged door 20 for permitting the homeowner to retrieve goods from or place goods in the rear of the enclosure 14. In the first embodiment of the storage device 10 illustrated in FIG. 1, the rear hinged door 20 may extend through an exterior wall of the home 12 so that the homeowner can access the storage device 10 while inside the home 12.
The front door 18 of the enclosure 14 includes a lock 22 for locking the door 18 and a lock operator 24 for unlocking the lock 22. In preferred forms, the lock operator 24 includes a conventional alphanumeric keypad 26 for permitting the entry of keycodes. As described in more detail below, the lock operator 24 unlocks the lock 22 only when a correct keycode is entered into the keypad 26. The lock operator 24 may also be coupled with other types of entry controlling devices such as a card reader, voice recognition device, fingerprint identification system, infrared sensor, or radio signal controlled or contactless smart card having a computer microchip embedded thereon.
The rear door 20 of the enclosure 14 may also include a lock. However, since the rear door 20 is primarily provided for allowing the homeowner to gain access to the enclosure 14, it is preferably not coupled with the lock operator 24 of the front door 18. Instead, the rear door 20 may be provided with a separate keypad or other entry controlling device for permitting the homeowner to access the enclosure from the rear door 20.
As best illustrated in FIG. 3, the enclosure 14 may also include a conventional door switch 28 operably coupled with the front door 18 for sensing when the front door 18 is opened or closed. The enclosure 14 also preferably includes interior lighting controlled by the door switch 28 for illuminating the inside of the enclosure 14 when either of the doors 18, 20 are opened and an exterior indicator 30 such as an indicating light for indicating when goods have been delivered to and/or picked up from the storage device 10.
As best illustrated in FIG. 4, the lower walls 32 of the enclosure 14 are preferably insulated. A pair of insulated shelf sections 34 are positioned approximately 20" from the bottom of the enclosure 14. The lower insulated walls 32 and the insulated shelf sections 34 define an insulated compartment 36 in the bottom of the storage device 10 for receiving refrigerated or frozen items such as groceries.
The insulated shelf sections 34 are preferably hinged to the sides of the enclosure 14 so that they can be raised for placing the refrigerated items in the insulated compartment 36 or raised for placing larger items in the enclosure 14 when the insulated compartment 36 is not in use. To accommodate both frozen and refrigerated items, the insulated compartment 36 may be sub-divided into a lower freezer section and an upper refrigerator section.
The preferred enclosure 14 also includes a refrigeration unit 38 positioned within the insulated compartment 36 for cooling the compartment 36. The preferred refrigeration unit 38 is a thermoelectric cooling module such as those manufactured by the Tellurex Corporation of Traverse City, Mich. under the Z-MAX tradename.
The refrigeration unit 38 may also be configured as a heater, or the enclosure 14 may include a separate heating unit 40 (see FIG. 5) coupled with the insulated compartment 36 for maintaining the temperature of heated foods such as pizza or other delivered fast food items. Alternatively, the enclosure 14 may include a second, separate insulated compartment (not shown) so that both refrigerated and heated food items can be delivered to the storage device 10 at the same time, or three separate compartments so that refrigerated, heated, and frozen food items can be delivered to the storage device 10.
As best illustrated in FIGS. 3 and 4, the upper portion of the enclosure 14 preferably includes a clothes rod 42 for hanging laundry delivered on hangers. In preferred forms, the enclosure is ventilated so that dry cleaning solvents such as perchloroethylene contained on delivered laundry does not build up within the confines of the enclosure. The enclosure may also include a fan for providing air flow through the ventilation holes. The fan may be a separate unit or may be incorporated in the refrigeration unit 38 or heating unit 40.
The enclosure 14 may also include a pair of shelf sections 44 positioned above the insulated shelf sections 34 but below the clothes rod 42 for holding goods such as grocery sacks. The shelf sections 44 are preferably hinged to the sides of the enclosure 14 so they can be raised when not in use for permitting larger items to be placed in the enclosure 14. Those skilled in the art will appreciate that the shelf sections 44 may be arranged anywhere within the enclosure 14 and the enclosure 14 may include additional interior shelf sections and/or clothes rods.
The communication apparatus 16 is operably coupled with the enclosure 14 for controlling access to the enclosure 14 and for providing notification that goods have been delivered to or picked up from the enclosure 14. As best illustrated in FIG. 5, the preferred communication apparatus 16 includes a controller 46 and a transmitting device 48.
The controller 46 is preferably a conventional programmable logic controller (PLC), a microcomputer or other microprocessor device. The controller 46 may also be a conventional home security system controller such as those manufactured and sold by the ADT Corporation that is programmed to operate as described herein.
The controller 46 has conventional memory for storing a plurality of vendor codes. A unique vendor code is assigned to each vendor that delivers goods to or picks up goods from the storage device 10. For example, a laundry and drycleaning business may be assigned a vendor code of 333, whereas a local grocery store may be assigned a vendor code of 444. Numerous other vendors may also be assigned unique vendor codes. All of these vendor codes are stored in the memory of the controller 46.
For further security, each vendor may also be assigned or may assign each of their delivery people with their own unique employee code. This permits the controller 46 to not only identify which vendor makes deliveries, but also to identify which delivery person employed by the vendor is making the delivery.
A plurality of vendor messages are also stored in the memory of the controller 46. Each vendor message is associated with a particular vendor code. For example, the message "Laundry has been delivered" may be stored in association with the vendor code of 333 for the laundry and dry cleaning business. Similarly, the message "Groceries have been delivered" may be stored in association with the vendor code 444 for the grocery store. The vendor messages may be audio messages stored on a conventional audio tape device such as a phone answering machine coupled with or internal to the controller 46 or may be digitized and stored in the memory of the controller 46.
As illustrated in FIG. 5, the controller 46 is electrically coupled with the keypad 26, the door lock operator 24, the door switch 28 and the indicator 30. As illustrated in FIGS. 2-4, the controller 46 and the other components of the storage device 10 receive electrical power from a conventional source over a wire or wires 50. The storage device 10 may also include a battery for providing backup operation of the device in case of a power failure.
Whenever a key code is entered into the keypad 26, the key code is transmitted to the controller 46. The controller 46 is programmed to compare the entered key code with the stored vendor codes to determine if the entered key code matches any of the stored vendor codes. If it does, the controller 46 directs the lock operator 24 to unlock the door 18. The controller 46 also retrieves the vendor message associated with the matched vendor code. The controller 46 then sends this vendor message to the transmitting device 48.
The transmitting device 48 is responsive to the controller 46 for sending the vendor message to a location remote from the storage device 10. The transmitting device 48 may be any known communication device such as a phone, a programmable answering machine, or a modem configured for sending analog or digital messages over a conventional telecommunications network such as a phone line, a local area network or a wide area network whenever a delivery has been made. As best illustrated in FIG. 4, the transmitting device is coupled with the telecommunications network via cable 52. The transmitting device 48 may also be a radio frequency transmitter/receiver for transmitting the vendor message by radio signals.
Returning to FIG. 5, the controller 46 is also coupled with the refrigeration unit 38. The controller 46 is programed so that whenever a particular vendor code is entered into the keypad, it automatically turns on the refrigeration unit 38. For example, if the vendor code 444 for the grocery store is entered into the keypad, the controller 46 can be programmed to not only unlock the door lock 22 and transmit a vendor message to indicate that a delivery has been made, but to also turn on the refrigeration unit 38. The refrigeration unit 38 may be on a timer so that it runs only a predetermined amount of time or may include a switch that permits the homeowner to turn it off once the goods have been retrieved from the storage device 10.
The controller 46 may also be programmed for receiving a code from the homeowner to turn on the refrigeration unit 38 or the heating unit 40 a predetermined amount of time before a delivery is made. This permits the refrigeration unit 38 or heating unit 40 to cool or heat the interior of the enclosure before the goods are delivered. Alternatively, the vendor may be instructed to phone in or otherwise transmit his vendor code to the controller 46 before delivery is made for turning on the refrigeration unit 38 or heating unit 40.
The controller 46 is also coupled with the indicator device 30 to activate the indicator 30 whenever a delivery has been made. This provides the homeowner with a visual indication of the status of the storage device 10.
The controller 46 may also be equipped with an alarm bell for security. The controller 46 may be programmed to activate the alarm bell if either of the doors 18, 20 of the enclosure 14 are forced open or if a person otherwise tampers with the storage device 10 without first entering a valid vendor code or homeowner code. The controller 46 may also be programmed to send an alarm message to the police or a security company if any of these alarm conditions occur.
As illustrated in FIG. 5, the storage device 10 is preferably part of a delivery system that allows messages to be sent to and received from several locations remote from the enclosure 14. For example, a remote communications apparatus 54 may be placed in the homeowner's home 12 and another remote communication apparatus 56 may be positioned in a vendor's business. The remote communication apparatuses 54, 56 are similar to the communication apparatus 16 and each includes a controller 58, 60 and a transmitting device 62, 64.
In operation, a vendor makes a delivery to the storage device 10 by first entering a keycode into the keypad 26. The controller 46 compares the keycode to the stored vendor codes and unlocks the lock operator 24 only if the keycode matches one of the vendor codes.
If the entered keycode matches a vendor code, the controller 46 also retrieves the vendor message associated with the matched vendor code and sends it to the transmitting device 48 for transmitting to one or both of the remote communication apparatuses 54, 56. The transmitting devices 62, 64 of the remote communication apparatuses 54, 56 receive the vendor message, demodulate or otherwise process the message, and send the message to their respective controllers 58, 60. The remote controllers 58, 60 then display the message or otherwise indicate that a delivery has been made.
The communication apparatus 16 and the remote communication apparatuses 54, 56 may also be configured to permit the homeowner to send a message or notification to a vendor that goods are to be picked up. For this operation, a plurality of unique homeowner codes and a plurality of homeowner messages are stored in the memory of the controller 46. For example, the homeowner code 555 and the homeowner message "Please pick up laundry at XXXX Street" may be stored in the controller 46 for notifying a laundry business that laundry needs to be picked up.
Whenever the homeowner wishes to have goods picked up from the storage device 10, he or she merely enters one of these homeowner codes into the keypad 26. The controller 46 then determines if the entered homeowner code matches one of the stored homeowner codes. If it does, the controller 46 unlocks the lock operator 24, retrieves the homeowner message associated with the homeowner code, and directs the transmitting device 48 to transmit the homeowner message to the appropriate remote communication apparatus 54, 56, i.e., the remote communication apparatus positioned at the appropriate vendor.
The vendor codes, employee codes, and homeowner codes stored in the controller 46 can be changed by either the vendors and/or the homeowner in any conventional manner. Additionally, new codes can be added to the controller 46 and unused codes can be deleted.
The communication apparatus 16 and the remote communication apparatuses 54, 56 may also be configured for permitting the delivery of goods ordered from the Internet. For example, a customer may access a vendor's Internet website in a conventional manner and place an order for the purchase of goods. Along with the order, the customer sends a one-time vendor code that allows the vendor or the vendor's delivery person to deliver the goods to the storage device 10. The controller of the communication apparatus 16 would be programmed to not only unlock the front door 18 upon entry of the vendor code, but to also send a notification message to the customer and a payment message to the vendor to charge or debit the customer's account for the price of the goods.
The communication apparatus 16 may also include memory for storing delivery and pickup information such as a history of the deliveries made to the enclosure 14 and conventional input/output devices for permitting the homeowner to access this information.
Although the invention has been described with reference to the preferred embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. For example, although the invention has been described and illustrated as being attached to a home, it can be readily modified for attachment to other buildings such as apartments.
Additionally, another embodiment of the invention might include a plurality of storage devices grouped together in a common area of a housing subdivision or an apartment complex, similar to the way mailboxes are grouped in newer subdivisions. The keypad and controller of each of the communication apparatuses would be configured to allow access to each of the storage devices and would direct the vendor, homeowner, or apartment dweller to use whichever storage device was currently empty. The communication apparatuses would then notify the homeowner or apartment dweller to which enclosure the delivery was made.
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A storage device (10) that secures goods from theft and exposure to the elements and that provides a notification that goods have been delivered and/or picked up is disclosed. The storage device (10) includes an enclosure (14) for enclosing the goods and a communication apparatus (16) for providing notification that goods have been delivered or picked up.
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[0001] This application claims priority from U.S. Provisional Application 60/822,379 for a “SYSTEM AND METHOD FOR MONITORING OF PHYSIOLOGICAL PARAMETERS,” filed Aug. 14, 2006 by Frederick J. Buja, which is hereby incorporated by reference in its entirety.
[0002] Cross-reference is made to co-pending U.S. patent application Ser. No. 11/381,246 for a “SYSTEM AND METHOD FOR MONITORING TEMPERATURE AND PRESSURE DURING A MOLDING PROCESS,” by Frederick J. Buja, filed May 2, 2006, which claims priority from U.S. Provisional Application 60/676,761 for a “MELT DENSITY SENSING SYSTEM AND METHOD,” by Frederick J. Buja, filed May 2, 2005, and from U.S. Provisional Application 60/745,871 for a “MEANS TO SENSE AN INJECTED MELT FLOW FRONT CAVITY GAS VENTING AND PEAK MELT DENSITY POINT AND TIME TO FORM A MOLDED PART,” by Frederick J. Buja, filed Apr. 28, 2006, and all the listed applications are hereby incorporated by reference in their entirety.
[0003] The embodiments disclosed herein are directed to a system and method for monitoring of physiological parameters, and more particularly to a system employing an improved, low-cost thermocouple sensor bead to accomplish sensing of temperature and/or pressure variations, using invasive or non-invasive means.
COPYRIGHT NOTICE
[0004] A portion of the disclosure of this application 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.
BACKGROUND AND SUMMARY
[0005] Based upon improved thermocouple sensing technology, as described for example in co-pending U.S. application Ser. No. 11/381,246, various alternative uses and embodiments have been contemplated. The embodiments include, among others, the application of improved thermocouple technology to uses in medical or physiological sensing devices. Moreover, alternative or additional sensing devices (e.g., piezoelectric accelerometer) for sensing falls or sudden changes to the wearer may also be included in the series of sensors that are contemplated for sensing physiological parameters. The following patents are also hereby incorporated by reference in their entirety: U.S. Pat. Nos. 6,649,095, 7,050,846, 7,051,120, 7,055,520, 7,060,030, 7,062,327, 7,063,669, 7,064,270, 7,065,396, and 7,065,409.
[0006] In one embodiment, the disclosed system and method may be used to sense temperature and pressure of a specimen (e.g., a mammal) in a physiological setting. As disclosed herein, such sensing may be accomplished through non-invasive or invasive techniques. In those situations where direct exposure of the thermocouple junction is not possible, the junction may be encapsulated in a flexible, thermally-conductive covering so as not to impede the sensing of pressure and temperature variations. It should be appreciated that a thermocouple formed with a generally-spherical, micro-bead type junction may be employed to sense not only changes in temperature, but also localized changes in pressure. In such embodiments, the reduced-size thermocouple junction is preferably exposed to the physiological environment it is designed to sense in order to reliably provide a signal response to changes in temperature and/or pressure. As discussed below, the response of the micro-bead thermocouple (e.g., a bead formed by laser welding of 0.010 inch thermocouple wires made from iron, and constantan or other known thermocouple combinations) is capable of sensing both temperature and pressure components.
[0007] Disclosed in embodiments herein is a physiological sensor, comprising: a thermocouple having a bead-shaped junction suitable for exposure to a physiological processes, whereby the junction can sense a physiological parameter, said thermocouple producing a signal in response to the physiological parameter; and circuitry connected to the thermocouple for receiving the signal, converting the signal to data representing the physiological parameter, and at least temporarily storing data representing the physiological parameter.
[0008] Further disclosed in embodiments herein is a method for sensing a physiological parameter, comprising: providing a thermocouple including a bead-shaped junction suitable for exposure to a physiological processes; exposing the bead-shaped junction to the physiological process, whereby the junction produces a signal in response to the physiological parameter; receiving the signal; converting the signal to data representing the physiological parameter; and at least temporarily, storing data representing the physiological parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram illustrating various components in a system for sensing physiological parameters;
[0010] FIGS. 2 and 3 are exemplary illustrations of several embodiments for the placement of sensors;
[0011] FIGS. 4A and 4B are illustrations of the thermocouple micro-bead in accordance with the disclosed embodiments;
[0012] FIG. 5A is a graphical illustration of the relationship between temperature and pressure on the micro-bead junction, and FIG. 5B is a graphical illustration of a manner in which the micro-bead thermocouple may be “calibrated” for a particular ambient environment;
[0013] FIG. 6 is an illustrative view of an embodiment of the disclosed system and method for sensing various parameters including blood pressure and fluid flow rate;
[0014] FIG. 7 is a further illustration of the device of FIG. 6 showing additional system features and functionality;
[0015] FIGS. 8A and 8B are illustrative examples of a pressure profile that may be generated in accordance with the embodiment depicted in FIG. 6 ; and
[0016] FIG. 9 is an illustrative example of respiration data acquired in accordance with the disclosed system and methods.
[0017] The various embodiments described herein are not intended to limit the invention to those embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0018] As more particularly set forth below, the disclosed system and methods are directed to physiological sensors for use on humans and similar mammalian specimens. Although described with respect to non-invasive embodiments, the disclosed systems and methods may be employed with more invasive techniques in a similar manner.
[0019] Referring to FIG. 1 , there is depicted a block diagram of a physiological sensor 110 in a monitoring system 120 for a human 130 . The sensor includes at least one thermocouple having a bead-shaped junction suitable for exposure to a physiological process(es), whereby the junction can sense a physiological parameter, the thermocouple producing a thermal energy work signal in response to the physiological parameter such as the specimen's temperature, pulse rate, etc. The sensor provides an output signal from the thermocouple junction in the form of a voltage (V emf ), that is passed to circuitry 140 for processing. In one embodiment, the circuitry may include an amplifier(s) 142 for amplifying the EMF voltage (V emf ), and an analog-to-digital (A/D) converter 144 for converting the V emf to a digital value or representation. Under the control of a processor or CPU 146 , the data is collected from the A/D converter and at least temporarily stored in memory 148 , and may be subsequently processed and transmitted, etc. As will be discussed relative to the processes described below, the processor 146 may perform various calculations to both adjust the readings as well as to provide desired physiological output For example, in addition to converting the voltage to a temperature, the system also corrects the temperature to a standard ambient condition (e.g. 14.7 psi pressure).
[0020] As also depicted in FIG. 1 , the system 120 may include one or more workstations, or similar handheld computing devices (e.g., Blackberry™, Palm Pilot™, iPOD™) that interface or at least receive the data from circuitry 140 . In one embodiment, the workstation 160 may also provide programmatic control software to the processor 146 through wired 170 (direct serial, parallel, USB, network) or wireless 172 (infrared, radio frequency, Bluetooth™, etc.) communications means or links. Similarly, the workstation or handheld device may permit a user to control operation of the system, including the frequency of monitoring (continuous, periodic, based upon a trigger point, etc.), the amount of data to store (e.g., all, last five readings, etc.), the method for transmission of data, as well as specimen data (name, patient identification code, etc.). Although not depicted it will be appreciated that conventional interface components and circuitry may be employed to accomplish one or more alternative communications links within the system of with external devices to which the system may send physiological parameter data.
[0021] Relative to the workstations or handheld devices, it should be appreciated various instruments are suitable for receiving signals produced by one or more of the sensors described herein and logging or otherwise recording the signals. The instruments may further include the ability to display data that is representative of the signals (processed and unprocessed), e.g., over time. As will be appreciated, it may be necessary to precondition or otherwise process the signals from the various sensing devices. For example, it may be necessary to provide amplification or similar processing in relation to the thermocouple signals generated.
[0022] Returning to the example above, the sensor may provide, via a thermocouple bead sensor 110 placed in or near the patient's mouth, the physiological parameter of body temperature. Here again, the circuitry stores data over a period of time to sense changes in temperature and to thereby represent a physiological process. In a further contemplated embodiment, the sensors 110 may be employed to sense temperature at a plurality of sites or locations in or on a specimen.
[0023] In the examples set forth in FIGS. 2 and 3 , alternative sensor placement and types are illustrated. FIG. 2 , for example, depicts the placement of an array of three thermocouple bead sensors 110 in the respective nasal and mouth area in order to sense the respiration of a specimen. Such an array of thermocouple bead sensors may be employed to sense respiration from multiple orifices (e.g., nose, mouth) similar to the respiration sensing suggested in U.S. Pat. No. 5,832,592, issued Nov. 10, 1998. FIG. 3 is one example of a sensor that may be placed next to an artery of a specimen in order to sense pulse or blood pressure and the like.
[0024] As depicted for example in FIGS. 4A and 4B , the bead-shaped junction 410 is a micro-bead where the thermocouple senses changes in a thermo-mechanical response as an expansion/contraction from heat and compression decompression of pressure exerted on the bead-shaped junction, thereby producing a signal including a pressure component. In other words, the response of the micro-bead junction includes an enhanced or amplified pressure response, from the response of the bead surface area, so that the pressure and temperature may be both be sensed simultaneously. Thus, the sensor generates, through the micro-bead junction, a thermo-mechanical response that includes a response to an encompassing gas, liquid, or solid pressure fluctuation. It will be recognized that the micro-bead may be formed as a contact region between two dissimilar metal wires (e.g., iron and constantan) that produce a varying voltage in response to changes in temperature and pressure. Moreover, at least one of the dissimilar metal wires has a generally round cross-section. As illustrated in FIG. 4B , the contact is a welded contact, preferably welded using a low-power laser so as to minimize the size and inner core density (K) change of the thermocouple junction and the associated or surrounding bead. The response of the sensor bead to pressure (mechanical) variability is believed to be significantly enhanced by reducing the size of the bead. Thus, micro-beads having small diameters are believed preferable. Ranges of micro-bead diameters on the order of 0.10 inches and smaller are believed to be preferable, and micro-beads having sizes of about 0.001-0.010 may prove to provide suitable responses.
[0025] In one embodiment, the sensor employed for sensing pressure, temperature, etc. may be a sheathed sensor with a 0.060″ diameter, which can be purchased from Omega with stripped wire ends suitable for welding. In accordance with U.S. application Ser. No. 11/381,246 (Publication 2006/0246167 A1), by Frederick Buja, hereby incorporated by reference in its entirety, the thermocouple is preferably formed with a micro-bead junction, wherein the smaller the bead size, the more sensitive the junction is to changes at the bead surface to temperature and pressure, etc. More specifically, the response of the micro-bead junction is a combination of the temperature and pressure fluctuation acting as work energy on the EMF junction. The strain of the spherical bead is directed to the EMF junction. As a further illustrative example, consider a bead surface area change from MEAN Diameter=Pi·D 2 ±ΔD. The area Increase is not equal to the change from nominal by the factor +2 ΔD 2 or (D±ΔD) 2 , where (D+ΔD) 2 =2D 2 +2ΔD+ΔD 2 and (D−ΔD) 2 =2D 2 −2ΔD+ΔD 2 . Rather the area is smaller by the same that the ±2ΔD factor, but the smaller area is less by a +ΔD 2 exponential ratio, thereby leading to force concentration and responsiveness to pressure variations. Where the junction size decreases from compression of the bead, the pressure sensed on the junction of the thermocouple is effectively increased, wherein the traditional thermocouple junction further becomes sensitive to pressure changes as well as temperature changes, and can produce signals indicative thereof. In other words, the micro-bead junction is believed to produce a significant EMF response to both changes to temperature as well as pressure.
[0026] Considering the thermal-mechanical response of the micro-bead thermocouple, the response may be predicted in terms of thermal-mechanical flex ( B Z) in relation to the illustrations found in FIGS. 5 A-B.
B Z eE =Thermal-Mechanical Flex= B T e · B M E ;
Δ B L E /π(Spherical Bead)=Δ B D E ;
A F G,L,S = A P G,L, · SB A E0 , representing applied bead surface force
B Z=[ B CD eE @ T=0 +( B mD eE · B T eactual )]·[( B D E0 · A F G,L,S )/( B A E0 · B D E )];
B Z=[ B C eE @ T=0 +( B m eE · B T eactual )]·[( A P G,L,S · B D E0 )/( B D E )];
A F G,L,S = A P G,L,S · B A E0
B K eE =Bulk Modulus #/In 3 Volume=FORCE on Bead;
where matter D is bead diameter, state ( A )= A G=Gas, A L=Liquid, A S=Solid. For Thermal B (e) Linear Flex and Mechanical B (E) Linear Flex, the relationships may respectively be stated as:
B L e =Circumference=π· B D e and
B L E =Circumference=π· B D E .
Therefore, in a spherical bead the
Thermal Diameter= B D e = B L e /π; and the
Mechanical Diameter= B D E = B L E /π
[0027] More specifically, the Spherical Bead ( B ) Thermal Flex is characterized as:
DiameterΔ B D T ≈ B D 0T ·[1+( B De·Δ B T )]
AreaΔ B A T ≈ B A 0T ·[1+(2· B De·Δ A T )]
VolumeΔ B V T ≈ B V 0T ·[1+(3· B De·Δ A T )]
where B T Afinal−B T Aactual =Δ B T Arange, and
B D e = B C e @ T=0 +( m B De· B T actual )
where B Ce@ T=0 =0.000006 In/in/° F.
m B e=0.0000000023″/° F.
therefore at B T eactual =0° F., B T e =0.000006 in./° F./in.
and B T actual =900° F., Ta=0.0000087 in./° F./in. 0.000006″+2.07×10 −6
[0028] And, the Spherical Bead ( B ) Mechanical Flex is characterized as:
B ΔD E =( B D 0 · A F G,L,S )/( B A E0 · B D E ) With A F G,L,S = A P G,L,S × B A E0
B ΔD B =( B D 0 · A P G,L,S )/( B D E )
therefore strain of enclosing substance A P G,L,S = B D E ·( B ΔD B / B D 0 )
where B ΔD E = B C@ T=0 +( B E · B T Eactual )
A F G,A F L,A F S , <==enclosing matter on sensor bead
where B D E @ T=0 =30,000,000#/In 2 and
m B De =(25,000,000−30,000,000#/In 2 )=−(5,000,000/900° F.)· B T actual
where B D E @ T=900 =30,000,000#/In 2 −5,000,000#/In 2 =25,000,000#/In 2
[0029] Referring to FIG. 5B , as a result of calibrating the bead to known temperature reference ice point (32° F.) and boiling point (212° F.) at an atmospheric pressure of about 1 Bar (14.7 psi) the thermal-mechanical (thermal flex) verification and certification can be accomplished, The response of the micro-bead thermocouple may be “corrected” to adjust for changes in atmospheric site pressure. FIG. 5 is a chart illustrating an exemplary correction for variations in pressure and temperature.
[0030] In one embodiment, the dissimilar metal wires have a diameter of less than about 0.006 inches. More specifically, the dissimilar metal wires may have a diameter of no larger than about 0.001 inches. In a cross-wire junction, where the contact that forms the EMF junction is not welded but is formed primarily through contact, the contact region may be less than about 0.000001 square inches in size.
[0031] Referring again to FIG. 1 , the circuitry may also include a timing circuit or chip 180 . One use of such a circuit may where the bead-shaped thermocouple junction is placed in proximity to a specimen's respiratory orifice(s) as in FIG. 2 , to sense respiration. There the circuitry would output data including a respiration rate based upon timing data from the chip 180 . Another alternative use of the timing capability may be to date/time stamp data produced by the circuitry. Yet another use of the timing chip is as a trigger for sensing one or more of the physiological parameters being monitored (e.g., pulse and blood pressure every 15 minutes) Although separately depicted, the timing chip or circuitry may reside on the processor or in other components of circuitry 140 or system 120 . Furthermore, those familiar in the design of such logic and control circuitry will appreciate that circuitry 140 will also include a power source, interconnecting ports (plugs, jacks and the like), and other components to facilitate interchange of signals and data as described herein. The various interconnections between the components are illustrated with single-line arrows, but are not intended to be limited to such construction and indeed the components may be connected in a printed circuit or other circuitry and may include multi-trace connections, a bus structure or other means for interconnecting the components. One embodiment also contemplated is the use of amplifiers and other circuitry components at the sensor location in order to make the sensors self-powered and suitable for remote monitoring by a more centralized system. Moreover, such a system may use telemetry or similar technology to periodically communicate with the sensors, thereby allowing the specimen being monitored to move about.
[0032] As depicted in FIG. 3 , for example, another embodiment contemplates the timing device 180 , where the bead-shaped junction is placed in proximity to an artery of a specimen to sense changes in the pressure of the artery. Based upon the sensing of pressure change, which indicates pumping of the heart muscle, the circuitry processes and outputs data including and indicating the specimen's heart rate. In yet a similar embodiment, a plurality of sensors may be used to provide data on blood pressure and the flow of blood in an artery. For example, referring to FIG. 6 , there is depicted a remote, self-contained blood-pressure sensor 610 that may be applied to a specimen's forearm (wrist) or similar location. The sensor includes a housing 612 that encompasses components of the circuitry described above, but in this embodiment is capable of regularly receiving signals from a plurality or array of micro-bead thermocouples 620 a and 620 b . The array of sensors detect temperature and pressure changes as described above, and the array would include two “lines” of between about ten and twenty, or more, regularly-spaced thermocouple sensors as described above. In one version of the depicted embodiment, a resilient or spring-like member 630 is employed in a slightly convex configuration to assure that when worn by a specimen, the thermocouple junctions remain in proximity to or in contact with the skin and an underlying artery. Lastly, the housing and sensors are attached to the specimen's arm using an arm or wrist band 640 , where the ends of the band may be connected when in use via hook and loop type fastener (e.g., Velcro™), snaps or similar disengageable fasteners not shown).
[0033] FIG. 7 provides an illustrative example of the relationship of the thermocouple arrays 620 a and 620 b with an artery 710 . It is preferable that the arrays be generally perpendicular to the artery for placement, so that the separation distance between the arrays 620 a and 620 b may be employed to determine flow rate (e.g., time for a pulse to propagate from sensing by first array ( 620 a ) to the second array ( 620 b )). The distance between each of the plurality of sensors in the arrays is either known or can be calculated based upon the spacing within the line of sensors and the separation of the two lines of sensors.
[0034] As a self-contained sensor, the device 610 can also exchange data with a workstation or portable computing device 160 . And, as illustrated in the display region of the device 160 , the user or medical personnel may view the data generated by the sensors in a convenient format. More specifically, display 162 may include one or more charts or graphs depicting processed sensor data over time, thereby showing the changes or trends in the specimen's physiological processes. It will be appreciated that such systems may be contemplated for patient monitoring and the like. Having described one embodiment, the collection and processing of data for illustration in display 162 will now be described in more detail.
[0035] Sensing of the temperature from one of more of the micro-bead thermocouple junctions is primarily an operation of collecting data from one of said junctions over time. Sensing the pulse (heart rate) and blood pressure are slightly more involved, and require further processing of the signals and data from the arrays and will now be described. Referring briefly to FIG. 8A , there is depicted a typical sensor profile from a single micro-bead thermocouple. The profile exhibits successive peaks 810 that are indicative of the thermo-mechanical characteristics sensed by the micro-bead junction. The peaks 810 are representative of the maximum pressure exerted on the sensor by the artery, when the artery is likewise expanded in response to pumping or pulsing of the heart. Thus, the peaks are representative of the heart and the associated or relative pressure at which it pumps. Similarly, the base-line 820 is indicative of the artery pressure at rest. It will be appreciated that the sensors may be used to indicate relative changes in pressure or temperature over time, or they may be “calibrated” by taking equivalent pressure readings at the beginning of a sensing session and then the data merely tracks changes in the pressure over time. Alternatively, an additional pressure or thermal sensor may be employed to correct or permit adjustment for changes in ambient pressure or temperature.
[0036] A profile such as that depicted in FIG. 8A , when taken across a plurality of sensors in array 620 a or 620 b , may produce a plot as depicted in the three-dimensional profile of FIG. 8B . In FIG. 8B , it can be seen that there is a central region in which the pressure sensed is greatest, and the pressure tails off to either side (front-back). Such a profile would suggest that the artery is under the approximate middle of the array and that the signals from the arrays sensing the peak data may be employed to calculate and monitor the blood pressure and heart rate. Conversely, the sensors on the extremes of each array have little or no change in signal level due to the heart pumping, and should be used as indicators for the localized temperature readings. To determine the blood pressure then, the system processes the profiles generated by those sensors determined to be located on or closest to the artery (having greatest pressure swings with heart pumping). The signals of such a sensor(s) are then employed to produce resulting pressure data and to produce corresponding systolic (max.) and diastolic (min.) pressure for each heart pumping cycle. These pressure can be stored and saved in memory so as to permit further processing and display as shown in the middle chart or graph in display 162 ( FIG. 7 ). Similarly, the pulse or heart rate can be calculated based upon the time interval between successive peaks (or a plurality of contiguous peaks), and this information can also be periodically stored and represented in the display 162 , where the pulse rate is illustrated in the lower portion of the display. It is further contemplated that rather than a table or chart, various of the physiological parameters discussed herein may be displayed as simple numbers reflecting the current or most recently measured state. In a numeric display it may also be advantageous to show the associated maximum and/or minimum values as well so that a medical practitioner has a better sense for the information being review.
[0037] In yet another embodiment of the system, the device may provide a plurality of spaced-apart sensors and a timing device, where bead-shaped junctions for each of said thermocouple sensors are placed in proximity to an artery of a specimen and said circuitry outputs data including a flow rate of blood flowing through the artery. The flow rate would be determined by the delay between sensing say a peak for each heart pulse on the first array and the second array. Knowing the spacing between the arrays (more specifically between the sensors on the arrays via a vectorial distance calculation), the system can determine the time required for the blood pulse (artery pressure surge) to propagate through the artery and thereby estimate the flow rate.
[0038] In accordance with the embodiments illustrated in FIGS. 6-8B , there is depicted a sensor, wherein the physiological parameter is blood pressure, and where the circuitry stores data over a period of time to sense changes in blood pressure and thereby represent a physiological process. As noted, the sensor may also include a system, attached to said circuitry, to periodically receive the data, and to process the data for display on a device 160 (e.g., display 162 ). In addition, the collected data may be displayed for one physiological characteristic at a time or multiple characteristics may be displayed at one time. For example, display 162 in FIG. 7 illustrates temperature, blood pressure and pulse data in an exemplary representation of the top, middle and bottom portions of such a display.
[0039] In the event that device 160 were connected to sensors such as those depicted in FIG. 2 , the display would depict the monitoring of the physiological parameter of respiration, where the circuitry again stores data over a period of time to sense a respiration rate and to thereby represent the physiological process of respiration.
[0040] As noted herein, the sensors 110 comprise one or a plurality of the micro-bead thermocouples, each having bead-shaped junctions wherein the physiological parameter is temperature and rate of respiration. In light of the various examples, it is apparent that various combinations of parameters may be sensed, wherein at least one sensor monitors a first physiological parameter and at least one other sensor monitors a second physiological parameter.
[0041] Per Merk (Merck Manual, 18th Edition, Copyright 2006 by Merck & Co., pp. 2549-2550), medical professionals are advised to observe the “ABCD's” for assessment in emergency situations (airway, breathing, circulation and disability). Accordingly, also contemplated in accordance with the disclosed embodiments is a signaling system, where based upon one or more of the physiological parameters being monitored, the system is able to signal (electrically, audibly or visually) medical personnel to indicate the status of the patient to whom the sensor is attached. For example, the presence or lack of sensed respiration could be signaled and to those working in a triage situation to quickly assess those injured or wounded, such information may be important. One contemplated embodiment includes a signaling component that indicates whether the specimen is respirating, and if so signals each respiration, or otherwise signals that the specimen has expired. The disclosed sensor and method may be employed to sense and monitor responses to gases, liquids, and solid acting on the bead. Hence, the sensor may be employed in a triage situation for sensing of the nasal/mouth respiration. Easily applied to multiple victims in a triage situation, the respiration sensor could quickly indicate those that are or are not breathing. The fused bead is a three-dimensional sphere and that is capable of sensing a small pressure rise or fall as a “temperature” response. Positioned in or adjacent a patient's nose, mouth or otherwise within the respiratory organs, the sensor would provide signals indicative of pressure and temperature changes.
[0042] The disclosed embodiments also contemplate the methods for sensing a physiological parameter. Such methods include the steps of (i) providing a thermocouple including a bead-shaped junction suitable for exposure to a physiological processes; (ii) exposing the bead-shaped junction to the physiological process, whereby the junction produces a signal in response to the physiological parameter; (iii) receiving the signal; (iv) converting the signal to data representing the physiological parameter; and (v) at least temporarily, storing data representing the physiological parameter. It will be appreciated that the bead-shaped (micro-bead) junction may be exposed in a non-invasive fashion or in an invasive fashion (within a flexible and temperature transmissive enclosure or envelope such as the end of a probe, catheter or the like). Preferably, the bead-shaped junction is produced in the form of a micro-bead such that said thermocouple is highly sensitive to thermo-mechanical stimuli, thereby producing a signal including a pressure component as well as temperature. In other words, the system and method would monitor a thermo-mechanical response that includes a response to change in the pressure of a gas (e.g., respiration), liquid, or even a solid. As another example of an invasive embodiment, the micro-bead sensor may be inserted into a needle, and embedded within an elastomeric material suitable for transmission of temperature and pressure so that the sensor may be used to sense, for example, internal body temperature and/or body or fluid (e.g. blood, cranial) pressure.
[0043] As noted above, one parameter that may be monitored on a specimen is temperature, where the circuitry stores temperature data over a period of time to sense changes in temperature to thereby represent the physiological process. In some embodiments, it may be important to sense and collect temperature data at a plurality of sites on the specimen and an array of sensors, spaced apart or placed at desired locations, would serve such a purpose.
[0044] In the manner of sensing respiration, using the arrangement of sensors 110 depicted in FIG. 2 , the bead-shaped junction is placed in proximity to a specimen's respiratory orifice (nose, and/or mouth) to sense respiration over time, and a respiration rate is determined and output for display. The disclosed methods also contemplate placing the bead-shaped junction in proximity to an artery of a specimen to sense changes in the pressure of the artery, and where a heart rate, blood pressure and/or blood flow is determined and output. Moreover, the data collected and output may be displayed so that the user or medical personnel may review such information. The disclosed methods also contemplate interfacing to a signaling device, where signaling may be used to indicate whether the specimen is respirating, heart is pumping, etc., and if so signaling such, or otherwise signaling that the specimen has expired.
[0045] Although not specifically illustrated, it will be appreciated that additional sensors may be included with the disclosed system to provide additional feedback. For example, a sensor for the orientation of the specimen (lying down, standing or sitting) may be used to correlate the physiological parameters with the specimen's orientation. Similarly, a piezoelectric sensor may be included in an array of sensors, wherein a fall or collapse of the subject may be detected. It will be appreciated that the disclosed sensor and method further contemplates the use of the various sensors in a remote configuration wherein sensor data may be periodically or continuously collected and periodically transmitted via wired or wireless transmission means to a central location for review or analysis. The local system work by the user may also include processing, monitoring and/or alarm features and functionality.
[0046] In an anticipated use situation such a cardiac stress test, the micro sensor array initial state is known when the device is turned on. The site temperature and barometric pressure become the sensor base reference. A sensor array holding device on the patient causes a counter temperature and pressure change from the skin temperature and artery pressure. A caregiver applies the sensor to the patient. Immediately before the patient is about to engage in high motion activities or be placed in a high emotion environment, the caregiver turns on the automatic monitoring function, and proceeds with his or her duties while observing the patient to ensure that the patient is quiet until the monitor acquires a certain number of waveforms without resetting. Once this has occurred, the caregiver permit the high motion activity of the specimen to begin. An automatic high motion tolerance algorithm reduces the adverse effects of high motion artifacts from the main channel using the main channel and reference channel signals.
[0047] This invention also contemplates the ability, based upon respiration, temperature and the like, to accurately characterize a specimen's caloric energy exchange or expenditure. The noninvasive measurement of a patient's blood pressure is achieved automatically in high motion situations by using a caloric sensor in a method and system that acquires pressure waveform data as thermal elastic exchange occurs during the cyclic compression and decompression of an artery varies. As described above lateral and specifically spaced micro sensor array is applied to skin surface. The interrelationship of site ambient temperature and barometric pressure acting and underlying skin area and artery pressure is profiled and the subsequent data acquired from the signals is processed to characterize the physiological parameters.
[0048] The following discussion is directed to the calibration and use of the sensing system. Assuming, for example, a 98.6° F. body temperature; a 60/40 (systolic/diastolic) blood pressure; an approximately 60 beats per minute pulse rate, and approximately 12 respirations/min respiration rate, the chart depicts the results of calculated bead expansion and contraction with and site pressure input correction for atmospheric pressure.
[0049] Consider a sensor calibration reference point or “Ice Point” at 32° F. or 0° C. The sensed temperature to such a zero reference is known as is the signal generated by the thermocouple. The pressure may then be calibrated to a known or typical pressure (example 14.7 psi). As pressure increases or decreases, the bead compression or expansion is then a programmable correction, similar to the present automated cuff system. That is how the cuff sensed site blood pressure is corrected. In a similar manner, the present sensor may be corrected or calibrated based upon the volume of the micro-bead junction. The sensor bead change in volume may be characterized as
Delta V={Fb×Db}/{Ab×E}
where, Fb=Force on the Bead=Pa {Atmospheric Pressure}×As {Bead surface Area [π×D 2 ]}Note that pressure correction Z=thermal mechanical flex=(e)×(E). Steel expansion is NOT constant, as e=0.000006″ (micro-bead junction size)+0.0000000023×Temp actual (Ta). Hence, the Expansion rate increases as the temperature rises. And, E (Young's Modulus) is not constant, and although approximating 30,000,000 pounds per square inch at room temperature, the modulus drops with temperature rises (e.g., E=30,000,000−{(5,000,000/900)×Ta}). In other words, Temperature changes the fused bead Modulus.
[0050] AS suggested previously, the sensing system may be comparatively calibrated with a blood pressure cuff or similar means and a technician may assure correlation. Moreover, the process for conducting such a correlation test may be controlled and facilitated by a programmatic set of instructions stored in the associated workstation or handheld device 160 .
[0051] Once calibrated various physiological parameters may be monitored, including but not limited to:
[0052] Respiration Temperature
[0053] i. Inhalation □ ambient site source (Oxygen rich)
[0054] ii. Exhale □ Internal source (Carbon Dioxide rich)
[0055] Respiration Rate
[0056] i. Rest
[0057] ii. Active
[0058] Body Temperature
[0059] i. Surface
[0060] ii. Inner tissue
[0061] Vascular Body Pressure
[0062] i. Surface Palpitation
[0063] ii. Inner Vascular Pulse Range
[0064] Vascular Blood Pressure Nominal
[0065] i. Systolic High Blood flow start (60 PSI-120″ Hg)
[0066] ii. Diastolic Low Blood flow pulse fade (40 PSI-80″ Hg)
[0067] Vascular Blood Flow Rate
[0068] i. Rest
[0069] ii. Active
[0070] In accordance with the various aspects disclosed herein and in the details depicted in the exemplary embodiments of the attached figures, the disclosed sensor and method are believed suitable for monitoring one or more of the following: Temperature-Acceleration-Pressure-Pulse-Position-Sound.
[0071] The various embodiments described herein are not intended to limit the claimed invention to those embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope defined by the appended claims.
[0072] It will be appreciated that various of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following or future claims.
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Disclosed are systems and methods for enabling the acquisition of physiological parameters of a mammal or other specimen using thermo-mechanical responses (e.g., temperature, pressure and alternatively acceleration, pulse, position). In accordance with one example embodiment, a monitoring device for wired and/or wireless sensors is used to acquire a series of sensor signals that are attached to achieve the physiological measurements of a mammal vital signs is provided. The device includes a Temperature-Pressure (T-P) sensor configured to attach to respiration, vascular pressure and audio points of the mammal in a manner suitable for obtaining the acquired individual sensor electrical signal. The sensor system is configured to attach to alternative locations of the specimen in a manner suitable for obtaining electrical signals in communication with a signal receiver and transmitter. Physiological parameters, such as those associated with vital signs (temperature, pulse, respiration, etc.), can be obtained using the monitoring device and associated sensors.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuing application, under 35 U.S.C. § 120, of copending international application No. PCT/AT2006/000408, filed Oct. 9, 2006, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of Austrian patent application No. A 1652/2005, filed Oct. 11, 2005; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to the combined use of starches or starch derivatives with high-viscosity celluloses as thickeners in paint systems featuring surprisingly high thickener performances not to be expected, as well as dispersion paints for inside and outside use resulting therefrom.
[0003] It is known to the skilled artisan that current interior and exterior wall paints based on aqueous systems frequently contain four main components, namely fillers, pigments, binders and water, as well as a plurality of important small components such as dispersants, detergents, defoamers, film formers, retarders, preservatives, biocides, salts, acids, bases, buffers, stabilizers, water glass, silica, organic solvents, thickeners etc.
[0004] The skilled artisan also knows the most diverse differentiations or synonyms for those dispersion binder-based paints, such as dispersion paint, wall paint, interior paint, rub-fast paint, washable paint, emulsion paint, brilliant paint, super-brilliant paint, satin paint, exterior paint, facade paint, filler paint, silicate paint, single-layer paint, double-layer paint, solvent paint, construction paint, structural paint, concrete coat, resin-bonded plaster, mineral plaster, dry dispersion paint, spray paint, primer, sand paint etc.
[0005] It is further known to the skilled artisan that such interior and exterior wall paints contain, above all, cellulose derivatives as thickeners and rheology-imparting agents. These include hydroxyethyl celluloses (HEC), methyl celluloses (MC), methyl hydroxyethyl celluloses (MHEC), ethyl hydroxyethyl celluloses (EHEC), hydroxypropyl celluloses (HPC), carboxymethyl celluloses (CMC), carboxymethyl hydroxyethyl cellulose (CMHEC), aminated celluloses etc. These powder products frequently are additionally modified to be swell-retardant.
[0006] Depending on the thickening effect, distinction can be made between high-viscous, medium-viscous and low-viscous celluloses. In order to give the paint producer a benchmark for the thickener performance, viscosities of 2% solutions are frequently used for a coarse classification. A cellulose having a viscosity of about 2,000 mPa·s (and less), measured by the Brookfield rotation viscometer at 5 rpm and 25° C., thus, means a low-viscosity variant, while a product of 50,000 mPa·s (and more) represents a high-viscosity cellulose. Products having viscosities in between can be classified as medium-viscosity celluloses. This viscosity classification also allows for the comparison of differently substituted celluloses such that, for instance, even methyl celluloses and hydroxyethyl celluloses can be assessed in a comparative manner. As a rule, low-viscosity and medium-viscosity cellulose ethers are used as thickeners in dispersion paints. This will, in particular, be the case with high-quality paints. However, also high-viscosity cellulose ethers are sometimes used to adjust the rheology of paints, particularly in the case of low-quality paints.
[0007] In addition to celluloses, also other thickeners such as inorganic bentonites, synthetic polymers and copolymers based on methacryl, acryl, vinyl and PUR, as well as organic, modified materials based on guar, alginates, pectin, xanthene, tragacanth and even starch are used.
[0008] Starch and starch derivatives may additionally be used as binders in single paints, which, by definition, are paints containing no synthetic binders. International patent disclosure WO 97/12946 (corresponding to U.S. Pat. No. 5,972,093), in addition to the use of milk casein, egg proteins and egg yolks, also describes the use of potato flour and starch pastes in water-based exterior and interior wall paints. Overall, up to 30% of natural binders are used in that case. Something similar is disclosed in published, European patent application EP 1 477 535. Also there, the starch functions as a binder in single paint systems.
[0009] U.S. Pat. No. 4,716,186 relates to cold-water-soluble, granular starch derivatives and their use as thickening agents in dispersion paints. Those starch derivatives are selected from the group of granular methylated, ethylated or carboxy-methylated starch materials, wherein the thickening agents are soluble by at least 90% at 25° C. Water has a medium methyl, ethyl or carboxymethyl substitution degree (SD) ranging from about 0.15 to about 1.0 of such substituents per anhydroglucose unit in the starch molecule, and a ratio of the inorganic anion content (in mass percent based on the dry mass of the starch derivative) to the methyl, ethyl or carboxyl substitution degree of about 14 or below.
[0010] Published, European patent application EP 0 979 850 discloses associative thickeners. Associative thickeners do not form networks by themselves, but lead to associations of particles already present in the fluid. They have tenside character, since they comprise both hydrophilic and hydrophobic end and side chains. They consequently form, for instance, micelles and thereby contribute to an increase in the viscosity. Moreover, they are able to associate in dispersions, e.g. water-based paints, with the latex particles present therein to and link the same by “micelle bridges”.
[0011] Published, non-prosecuted German patent application DE 2 005 591 A2 finally relates to textile printing pastes formed of water, a dye, at least one polymeric organic thickening agent dissolving almost completely in water, and at least one cross-linked starch derivative swelling in cold water, yet practically insoluble in cold and/or hot water.
[0012] U.S. Pat. No. 5,118,732 relates to a rain-resistant sealing composition containing aqueous polymer dispersions, non-ionic cellulose ethers selected from the group of hydroxyethyl, hydroxyethyl methyl, hydroxypropyl methyl and hydroxypropyl celluloses, as well as optionally typical additives like fillers, pigments, softeners etc.
[0013] In published, European patent application EP 0 307 915 A2, anionic water-soluble carboxymethyl hydroxyethyl derivatives of cellulose ethers are disclosed, which are usable as thickeners in aqueous compositions such as water-based paints and which contain a hydrophobic alkyl, alpha-hydroxyalkyl or acyl modification group with 8-25 carbon atoms and, in their polymer structures, comprise mass ratios of about 0.1 to about 4%, the carboxymethyl substitution degree ranging between about 0.05 and <1.
[0014] Published, European patent application EP 0 601 404 A1 (corresponding to U.S. Pat. No. 5,455,341) relates to specific, highly substituted carboxymethyl sulfoethyl cellulose ethers (CMSECs) and a simplified and economic method for producing such highly substituted ethers as well as their use as thickening agents in textile printing.
[0015] Published, Japanese patent application JP 03-0348971 A finally relates to a foaming water-based fire-protection paint containing an emulsion of synthetic resins, a foaming agent and a carbonizing agent as well as viscosity controllers containing cellulose derivatives and having viscosities of 10-400 Pa·s.
[0016] According to the reference titled “Starch Derivatisation” by K. F. Gotlieb and A. Capelle, Wageningen Academic Publishers, The Netherlands, 2005, p. 47, hydroxyethyl celluloses have long been used in the starch industry—apparently for wallpaper pastes—to “enhance” (cross-linked) carboxymethyl starches as thickeners in technical applications. Special applications are not mentioned, nor has any synergistic effect been expressly observed.
[0017] The basic advantage of the use of starch, modified starch and starch derivatives in technical products relates in that starch is an annually renewable natural raw material which is available at low cost and in excess and can be obtained and modified by environmentally compatible processes. That is why starch is, in fact, frequently used in technology for the most diverse purposes.
[0018] Starch derivatives are able to fulfill various functions in technical applications. Thus, starches and starch derivatives are already used as adhesives, coatings and, inter alia, rheology-imparting agents, in particular thickeners, in many applications. Depending on the respective demands and additional properties sought, starches are more or less strongly modified. If used as thickeners, etherified and/or esterified products are often employed. Such products are frequently also cross-linked. Cross-linking imparts a certain stabilization and, hence, shear stability to the product. On the other hand, the substitution is aimed to induce strong swelling and, hence, a strong water-binding potential, thus leading to products having strong thickening effects.
[0019] In dispersion paints, starch-based thickeners are hardly of importance. Although all large starch manufacturers refer to that certain products can be used in paints, none of them has yet offered their own products, much less own product ranges, for paints as opposed to paper, construction and textile applications. When solely used as rheology-imparting agents, starch products offer insufficient thickener performances to compete with celluloses. Such products have accordingly not been able to prevail on the market.
BRIEF SUMMARY OF THE INVENTION
[0020] It is accordingly an object of the invention to provide a thickener for paint systems which overcome the above-mentioned disadvantages of the prior art methods and devices of this general type.
[0021] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for producing a dispersion-binder-based paint system. The method includes the step of admixing a combination of at least one starch with at least one high-viscosity cellulose to the paint system as a thickener. The cellulose has a viscosity of >50,000 mPa·s measured by a Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C. Ideally the viscosity can be set to >60,000 mPa·s and even >75,000 mPa·s.
[0022] It has now been surprisingly found that the combined use of starch(es) or starch derivatives with at least one high-viscosity cellulose, wherein the cellulose has a viscosity of >50,000 mPa·s, preferably >60,000 mPa·s and, in particular, >75,000 mPa·s, measured by the Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C., provides special advantages when used as a thickener in a dispersion-binder-based paint system. By the combined use according to the invention, of starch-cellulose thickeners, even starches have become competitive. Unlike pure celluloses, such paint thickener combinations almost result in identical viscosities, thus surprisingly exhibiting much higher viscosities than would have been expected on account of the large differences of the individual components. In aqueous systems, between 25 and approximately 40% of the celluloses can be replaced with starch derivatives without causing the aqueous system to loose its viscosity. In paint systems, the paint thickener combinations according to the invention are likewise able to substitute high-viscosity celluloses in portions of 0.1 to 30% and, preferably, up to 25% starch, and medium-viscosity celluloses in portions of 0.1 to 65% and, preferably, up to 50% starch.
[0023] In paint systems, between 0.05 and 1.2%, preferably 0.2-0.5%, cellulose thickeners are usually used. With the substitution provided according to the invention, of up to 65%, preferably 20-50%, of the cellulose quantity by starch, this would imply a use of starch of ˜0.01-0.78%, preferably 0.1-0.25%, in the paint system.
[0024] The apparent viscosity drawbacks mentioned in the context of starches solely used as thickeners in dispersion paints result in yet another, much more essential reason for their low market acceptance, namely that of deteriorating the quality of paints. The low thickener performances of starches may by compensated for by using two to three times the amount of product, yet such elevated amounts would entail dramatically deteriorated paint qualities, in particular in terms of washing and scrub resistances.
[0025] The combined use of starches and celluloses as in accordance with the invention, and the resulting paint, however, do not exhibit any of those drawbacks. By only using combined thickener amounts usual for celluloses, no “excess” of soluble polymer and, hence, no deteriorations of the washing and scrub resistances as compared to paints formed of pure cellulose will be caused, either. An essential impediment for the use of starches in such systems has, thus, been eliminated.
[0026] The present invention further relates to a method for producing a dispersion-binder-based paint system, wherein a combination of starch(es) with at least one high-viscosity cellulose is admixed to the paint system as a thickener either dry or in solution, the cellulose having a viscosity of >50,000 mPa·s, preferably >60,000 mPa·s and, in particular, >75,000 mPa·s, measured by the Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C.
[0027] Alternatively, starch(es) and at least one high-viscosity cellulose can be admixed as a thickener to the paint system separately at different times, the cellulose having a viscosity of >50,000 mPa·s, preferably >60,000 mPa·s and, in particular, >75,000 mPa·s, measured by the Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C.
[0028] The celluloses used in paints are usually swell-retarded so as to enable their homogeneous stirring into water without agglomeration. This swell-retardation will break very rapidly at alkaline pH-values. As a result, such swell-retarded celluloses in dry form can only be introduced at the beginning of the production of a paint. Any subsequent addition into the paint system, in particular after the addition of pigments and fillers, would cause too rapid swelling of the cellulose and, hence, an agglomeration of the cellulose. As a rule, the cellulose is stirred into the provided water, followed by lyes or ammonia, dispersants and wetting agents, pigments, fillers, defoamers, preservatives and binders. Celluloses that are not swell-retarded can only be introduced into aqueous systems at high technological expenditures, which is why such products will hardly be met on the paint market.
[0029] The starch products may, however, also be fed to the paint system at a later time without causing any inhomogeneities. The starches used in in-house experiments can, thus, be introduced at the beginning along with the cellulose, after the fillers, or even after the binder. This provides advantages by more flexible formulations and the option to adjust the viscosity by the aid of starch at the end of the formulation. The starch of the starch-cellulose combination is admixed to the paint system preferably at the end of the paint formulation prior to the addition of the binder.
[0030] On the market, celluloses having different degrees of polymerization and different viscosities are available, with medium-viscosity products representing the main portion in the paint sector within the EU. These medium-viscosity products are, above all, used in quality paints at higher amounts of use, while high-viscosity products at low amounts of use are rather used in cheap paints. Quality paints stand out for their high viscosities, little sagging, good leveling, good washing and scrub resistances, a reduced tendency to spatter (spatter resistance) and good coverage. Cheap paints mostly show little coverage and a moderate washing and scrub resistance, a poorer resistance to sagging and a high tendency to spatter, the poorer resistance to sagging and the tendency to spatter being caused by the small amount of thickener.
[0031] By the combined use of cellulose-starch thickeners as in accordance with the invention, such medium-viscosity cellulose derivatives can be perfectly substituted even while providing, in a surprising manner, improvements in the thus resulting paints as regards some properties, such as a reduced sheen and excellent roll quality. Correspondingly, the invention provides a dispersion paint thickener combination containing starch(es) or starch derivatives along with at least one high-viscosity cellulose, the cellulose having a viscosity of >50,000 mPa·s, preferably >60,000 mPa·s and, in particular, >75,000 mPa·s, measured by the Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C. Due to the possible combination of high-viscosity cellulose and starch, very high portions, i.e. up to about 60%, of starch can be introduced, with the overall amount of use corresponding to that of medium-viscosity celluloses, thus guaranteeing the good properties of quality paints. Improvements in the roll quality are, moreover, achievable. The paint thickener combination according to the invention, thus, produces paints exhibiting excellent properties both in terms of washing and scrubbing resistances and in terms of processing behavior.
[0032] The high-viscosity celluloses used according to the invention are preferably selected from the group containing hydroxyethyl cellulose (HEC), methyl cellulose (MC), methyl hydroxyethyl cellulose (MHEC), ethyl hydroxyethyl cellulose (EHEC), hydroxypropyl cellulose (HPC), carboxymethyl cellulose (CMC), cationic celluloses, and combinations thereof.
[0033] Sometimes, clients wish a thickening agent to have specific rheological properties. These can be obtained by adding special auxiliary agents and rheology-imparting agents to the thickener system. In this case, even further auxiliary agents and rheology-imparting agents such as salts, acids, bases, polyurethanes, synthetic polymers and copolymers based on acrylic and methacrylic acids, natural and semi-natural polymers based on chitosan, pectin, tragacanth, guar, alginate can be added to the starch and/or to high-viscosity cellulose of the paint thickener combination. It is exactly that combination with starch, which will provide enhanced improvements in terms of paint stability, leveling, sagging, rolling and spraying behaviors.
[0034] The paint thickener combinations described can also be used in dry dispersion paints and similar dry paint systems. The starch, due to its good solubility, offers great advantages exactly in this field of application.
[0035] Paint thickener combinations of this type are, moreover, made for use in dispersion-binder-bound paints and primers of ceiling panels and other construction materials. There, the special rheological properties of starch will take effect.
[0036] The most diverse starches and starch derivatives are suitable for use as starch-cellulose paint thickener combinations in dispersion paints. According to a preferred embodiment of the present invention, the starch or starch derivatives are based on corn starch, wheat starch, potato starch, tapioca starch, manioca starch, pea starch, rice starch, amaranth starch, rye starch, barley starch and their natural and transgenic waxy forms and natural and transgenic high-amylose forms, respectively.
[0037] Basically, starch is a natural plant product. It is formed essentially of a glucose polymer which, as a rule, constitutes a composition of two components, namely amylopectin and amylose. These are, in turn, no uniform substances, but mixtures of polymers having different molecular weights. Amylose is formed essentially of unbranched polysaccharides in which the glucose is present in an alpha-1,4-bond. Amylopectin, on the other hand, is a heavily branched glucose polymer in which the glucose units besides the alpha-1,4-bonds on the branch points are contained in 1,6-bonds.
[0038] Natural starches, as a rule, have amylose contents of from 15 to 30%. There are, however, also waxy type starches that have elevated amylopectin contents, and amylo-products having elevated amylose contents. In addition to natural and cultured natural waxy types and high-amylose types (natural hybrids or mutants), waxy starches and high-amylose starches prepared by chemical and/or physical fractionation, and waxy starches produced via genetically modified plants are available. All of these starches, either as such or in derivatized form, can basically be used in combination with high-viscosity celluloses as thickeners in dispersion paints.
[0039] In a preferred manner, these starches are modified for the combined use according to the invention, with high-viscosity celluloses as thickeners in dispersion paints. From the literature, a plurality of derivatives are known, whose preparation is amongst others well summarized in the reference titled “Starch: Chemistry and Technology”, R. L. Whistler, Chapters X and XVII, 1984, and in “Modified Starches: Properties and Uses”, edited by O. B. Wurzburg, Chapters 2-6 and 9-11, CRC Press, 1986. With starch derivatives, distinction is generally made between starch ethers and starch esters. Further distinction can be made between non-ionic, anionic, cationic and amphoteric as well as hydrophobic starch derivatives, which can be produced by slurry, paste, semi-dry or dry derivatization as well as derivatization in organic solvents.
[0040] The starch used according to the invention is preferably the product of an esterification or, alternatively, the product of an etherification. The subsequent derivatization options belong to the prior art.
[0041] By anionic and non-ionic modification of starch, those derivatives are embraced, in which the free hydroxyl groups of the starch are substituted by anionic or non-ionic groups. Unlike corn and waxy corn starch, potato and amylopectin potato starches have naturally bound anionic groups such that, in the proper sense, anionic starch derivatives will imply additional anionic modifications. They are, in fact, naturally chemically bound phosphate groups thereby imparting additional, specific polyelectrolytic properties to potato and amylopectin potato starches.
[0042] Basically, anionic and non-ionic derivatizations can be performed in two ways:
a) The modification is effected in a manner that an esterification of the starch will occur. Inorganic or organic, heterovalent, usually bivalent, acids or salts thereof or esters thereof or anhydrides thereof serve as modifiers. Thus, the following acids, whose enumeration is only exemplary, are inter alia suitable: o-phosphoric acid, m-phosphoric acid, polyphosphoric acid, various sulphuric acids, various silicic acids, various boric acids, acetic acid, oxalic acid, succinic acid and their derivatives, glutaric acid, adipic acid, phthalic acid, citric acid etc. Mixed esters or anhydrides can also be used. The esterification of the starch may also be effected several times so as to obtain, for instance, distarch phosphoric ester. The starch used according to the invention is preferably the product of an esterification with mono-, di- or tricarboxylic acids having alkyl chains with 1-30 carbon atoms, or a carbamate, in a particularly preferred manner acylated such as succinylated, octenylsuccinylated, dodecylsuccinylated or acetylated. b) The modification is effected in a manner that an etherification of the starch will occur. Inorganic or organic, substituted acids or salts thereof or esters thereof serve as modifiers. In this respect, it is particularly preferred, if the starch used according to the invention is a methyl, ethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, carboxymethyl, cyanoethyl, carbamoylethylether starch or a mixture thereof. By that type of reaction, the substituents will be cleaved while forming an ether group.
[0045] Consequently, the starch is, for instance, primarily substituted, or additionally substituted by phosphate, phosphonate, sulfate, sulfonate or carboxyl groups. This is, for instance, achieved by reacting potato starch with halocarboxylic acids, chlorohydroxyalkyl sulfonates or chlorohydroxyalkyl phosphonates.
[0046] By cationic modification of starches, those derivatives are summarized, where a positive charge is introduced into the starch by substitution. Cationization processes are performed using amino, imino, ammonium, sulfonium or phosphonium groups. Methods for producing cationized starches are, for instance, described by D. B. Solareck: Cationic Starches, in the book by O. B. Wurzburg (Ed.): Modified Starches: Properties and Uses, CRC Press Inc., Boca Raton, Fla. (1986), pp. 113-130. Such cationic derivatives preferably comprise nitrogen-containing groups and, in particular, primary, secondary, tertiary and quaternary amines or sulfonium and phosphonium groups bound by ether or ester bonds. The use of cationized starches containing electropositively charged quaternary ammonium groups is preferred.
[0047] Another group is represented by amphoteric starches. These contain both anionic and cationic groups, thus offering very specific application options. In most cases, these are cationic starches that are additionally modified either by phosphate groups or by xanthate. A disclosure for the production of such products is also given by D. B. Solareck: Cationic Starches, in the book by O. B. Wurzburg (Ed.): Modified Starches: Properties and Uses, CRC Press Inc., Boca Raton, Fla. (1986), pp. 113-130.
[0048] Starches can also be modified by the aid of hydrophobing reagents. Etherified hydrophobic starches will be obtained if the hydrophobic reagents contain a halide, an epoxide, a halohydrine, a glycidyl, a carboxylic acid or a quaternary ammonium group. For esterified hydrophobic starches, the hydrophobic reagent usually contains an anhydride. Carboxymethylated starches can already be hydrophobized by the aid of a hydrophobic reagent containing an amine group. The reactions mentioned may proceed in the presence of a tenside. A hydrophobization of starch can also be affected by mixing a starch or starch derivative with a fatty acid ester. The hydrophobic starches obtained by the cited reactions are likewise suitable for use in paint systems.
[0049] Esters and ethers of starches are of great importance. A distinction is made between simple starch esters and mixed starch esters, wherein the substituent(s) of the ester(s) may be different: in the ester residue RCOO—, the residue R may be an alkyl, aryl, alkenyl, alkaryl or aralkyl residue having 1 to 17 carbon atoms, preferably 1 to 6 carbon atoms, in particular one or two carbon atoms. These products include the derivatives acetate (prepared from vinyl acetate or acetane hydride), propionate, butyrate, stearate, phthalate, succinate, oleate, maleinate, fumarate and benzoate.
[0050] Such acylated, concretely succinylated, octenylsuccinylated, dodecylsuccinylated and acetylated starches exhibit very high thickening performances in aqueous systems and, therefore, are perfectly suited for paint systems.
[0051] Etherifications, in the main, are accomplished by reactions with alkylene oxides containing 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, and, in particular, by using ethylene and propylene oxide. Methyl, carboxymethyl, cyanethyl and carbamoyl ethers may, however, also be prepared and used. In a particularly preferred manner, the starch used according to the invention is a carboxymethylated corn or potato starch preferably having a carboxymethylation degree of substitution of DS 0.01-1.0, preferably DS 0.2-0.5.
[0052] Other products contain alkylhydroxyalkyl, alkylcarboxyalkyl, hydroxyalkyl carboxymethyl and alkylhydroxy alkylcarboxymethyl derivatives.
[0053] Besides the esters and ethers, or in addition to the derivatization, the starch used according to the invention can also be cross-linked, oxidized, thermochemically degraded, dextrinated or extruded to different extents, either as such or additionally.
[0054] Cross-linking is preferably carried out by reaction with epichlorohydrine, adipic acid, phosphoroxychloride or sodium trimetaphosphate, furthermore with 1,3-dichloro-2-propanol, optionally mixed with (poly)amines, furthermore with di- or polyepoxides, aldehydes or aldehyde-releasing reagents such as, for instance, N,N′-dimethylol-N,N′-ethylene urea and mixed anhydrides of carboxylic acids with di- or tribasic acids such as, for instance, a mixed anhydride of acetane hydride with adipic acid. The latter, and numerous variants of the same, can be embraced by the expression cross-linking with adipic acid.
[0055] It will be particularly preferred if the starch used according to the invention is acetal cross-linked, either as such or additionally. In a particularly suitable manner, the starch used according to the invention is glyoxal cross-linked or propionaldehyde cross-linked, acetal cross-linking being generally feasible using acetaldehyde, propionaldehyde, butyraldehyde, and even longer-chain aldehydes. Acetal cross-linked starches can be prepared and used either in combination with a further derivatization (etherification or esterification) or even without any further modification.
[0056] The starches used for the esterification, etherification and cross-linking procedures, in addition, may be tempered (in slurry) or inhibited (dry or semi-dry reaction) via thermo-physical modifications.
[0057] Special products according to the invention may be obtained via reactions of the starches and starch derivatives with the most diverse forms of glycide ethers, diglycide ethers, tri-glycide ethers, tetraglycide ethers and glycide esters. In this case, the reagents may also contain phenyl, cyclohexane, alkyl, propyleneglycol and other chemical groups. Examples include reagents like butanedioldiglycide ether, polyglycerol triglycide ether, o-cresol glycide ether, polypropylenediglycol glycide ether, t.butylphenyl glycide ether, cyclohexane-dimethanol diglycide ether, glycerol triglycide ether, neopentyl glycol diglycide ether, pentaerythrit tetraglycide ether, ethylhexyl glycide ether, hexandiol glycide ether, trimethylolpropane triglycide ether, perhydrobisphenole diglycide ether and neodecanoic acid glycide ester. The modifications mentioned can be carried out as such, in combination, or in combination with conventional esterifications, etherifications and physical or thermal treatments.
[0058] Pastes of the cross-linked starches at low cross-linking degrees exhibit very rapidly increasing viscosities, which will, however, decrease again at higher cross-linking degrees. Retrogradation is, however, very low in both cases, which is why the cross-linked starches will also be of great advantage when used in paints.
[0059] Particularly suitable are combinations of epichlorohydrine cross-linked carboxymethylated starches and epichlorohydrine cross-linked carboxymethylated and hydroxypropylated starches, cross-linking being feasible both in slurries and in pastes. Yet, also starches merely propionaldehyde cross-linked or modified in combination with the above-mentioned esterifications and etherifications will exhibit particularly good thickener performances in paint systems.
[0060] According to a preferred embodiment of the present invention, the starch(es) used according to the invention is/are starch(es) graft-polymerized or graft-copolymerized, for instance, with products from the group of polyvinyl alcohols, acrylamides, acrylic acids or monomers and polymers departing from petroleum hydrocarbons. In those cases, the starch-graft (co)polymer may preferably be present as an emulsion polymer.
[0061] As already pointed out above, the mentioned starch modifications may not only be obtained by reacting native starch, but the use of degraded forms is possible too. The degradation procedures may be realized in a mechanical, thermal, thermochemical or enzymatic manner. The starch can, thus, not only be changed structurally, but the starch products can also be made cold-water-soluble and cold-water-swellable (e.g. dextrination and extrusion).
[0062] According to a preferred embodiment, the starch, or modified starch, used according to the invention is cold-water-soluble. Cold-water-soluble starch, in particular, can be prepared with or without pregelatinization by roll-drying or drum-drying, spray-drying or spray-cooking etc. For the optimum development of the properties of the cold-water-soluble starch or starch derivatives, the degree of dissociation is of great importance. The starch and its derivatives will not show any agglomeration, dust formation and tendency to demixing during their dissociation and subsequent use and, therefore, afford an optimum processability in the practical application of a suitable dry product on paste base after stirring into water. In this respect, extrusion constitutes a special procedure. It enables modified starch to degrade to different extents by physical action while, at the same time, reacting to a cold-water-soluble or cold-water-swellable product. This technology, moreover, also allows for the direct chemical derivatization of starches in a cost-saving manner. The use of the spray-drying technology (and, in particular, spray-cooking technology) allows for the production of particularly high-viscous starches and starch derivatives which lend themselves perfectly as thickeners for paint systems.
[0063] Good swelling of the starch is necessary for the thickener effect to develop well in the paint. The addition of starch or starch derivatives, as a rule, is feasible in two different ways. Where a cooking starch is used, a concentrated starch paste must be prepared prior to its addition. To this end, the starch is stirred into water, and this starch slurry is heated to boiling, cooled down and then added to the paint system. It is only by the heat that the starch will be gelatinized and, hence, brought into a water-soluble state. Alternatively, a cold-water-soluble derivative can be introduced into the system, either predissolved or as such in powder or flake form, with the starch entering into solution without agglomeration under moderate stirring. The second variant is the preferred one, the more so as this would mean less technical expenditures for the end consumer.
[0064] The present invention further relates to a dispersion paint containing a dispersion paint thickener combination as described in detail above.
[0065] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0066] Although the invention is described herein as embodied in a thickener for paint systems, it is nevertheless not intended to be limited to the details described, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0067] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0068] The following examples serve to elucidate the present invention without restricting the same.
Example 1
[0069] The celluloses, starches and combinations thereof were stirred into deionized water in a 1-liter beaker at 1% in dry substance (DS) to a total of 500 g, adjusted to pH>9 with 1% NaOH, stirred for 10 min at 1500 rpm with an 80 mm (diameter) turbine stirrer, and measured by the aid of a Brookfield rotation viscometer after a swelling time of 24 h at 5 rpm and 25° C.
1.1 Comparison 1
[0070] Starch A (epichlorohydrine cross-linked carboxymethyl starch (CMS) based on potato starch; SD (CMS)˜0.33).
[0071] High-viscosity HEC 103,000 (at a viscosity of 2% in DS of 103,000 mPa·s).
[0000]
TABLE 1
Comparison aqueous solutions 1% in DS with HEC
Ratio
Brookfield Viscosity
Thickener
[% mass]
5 rpm, 25° C.
High-viscosity HEC
100
10,400 mPa · s
High-viscosity HEC/starch A
90/10
10,920 mPa · s
High-viscosity HEC/
75/25
10,120 mPa · s
starch A
High-viscosity HEC/
60/40
8,080 mPa · s
starch A
Starch A
100
96 mPa · s
[0072] Result: practically identical viscosity at replacement of 25% starch; almost no viscosity loss at portions of up to 40%, surprising effect based on the low viscosity of the pure starch solution.
1.2. Comparison 2
[0073] Starch A (cross-linked CMS based on KS).
[0074] High-viscosity MC 78,000 (at a viscosity of 2% in DS of 77,600 mPa·s).
[0000]
TABLE 2
Comparison aqueous solutions 1% in DS with MC
Ratio
Brookfield Viscosity
Thickener
[% mass]
5 rpm, 25° C.
High-viscosity MC
100
4,712 mPa · s
High-viscosity MC/starch A
90/10
12,320 mPa · s
High-viscosity MC/starch A
75/25
16,560 mPa · s
High-viscosity MC/
60/40
10,320 mPa · s
starch A
Starch A
100
96 mPa · s
[0075] Result: Higher viscosities when replacing 40%. Surprising effect based on the low viscosity of the pure starch solution.
Example 2
Use of Starch-Cellulose Combinations in Dispersion Paints
[0076] Formulation of interior dispersion paint by way of examples:
a) Paint I: Dispersion paint with pure cellulose thickener; b) Paint II: Dispersion paint using starch/cellulose at a ratio of 50/50 with the
addition of starch at the beginning of the formulation; and
c) Paint III: Dispersion paint using starch/cellulose at a ratio of 50/50 with the
addition of starch after binder.
[0000]
TABLE 3
Batch formulations for dispersion paints with and
without starch addition
Material
Description
Paint I
Paint II
Paint III
H 2 O
solvent
257.5
257.5
257.5
(deionized water)
Cellulose
thickener
3.4
1.7
1.7
Starch A
thickener
1.7
—
NaOH 25%
base
0.4
0.4
0.4
Coatex
wetting agent
2.3
2.3
2.3
Agitan 285
defoamer
1.5
1.5
1.5
Preventol D7
biocide
1.1
1.1
1.1
Kronos 2190
pigment
75.0
75.0
75.0
Finntalc M 30 SL
filler
52.5
52.5
52.5
Omyacarb 5-GU
filler
93.8
93.8
93.8
Omyacarb 2-GU
filler
187.5
187.5
187.5
Acronal LR 8961
binder
75
75
75
Starch A
thickener
—
—
1.7
Total
750
g
750
g
750
g
[0082] Execution:
[0083] Deionized water is provided, the cellulose (paint I) or cellulose-starch combination (paint II) is stirred in for 5 min and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, biocide, pigments and fillers is affected. Following a dispersion phase of 20 min, the binder is introduced, followed by the addition of starch for paint III. After 10 minutes of stirring, the paint is stored, and the viscosity and pH are determined after 24 h.
a) Comparison of thickener performances at different use ratios of cellulose/starch and at different starch addition times, respectively.
[0085] In the following dispersion paints produced, the same total amount of thickener (cellulose, starch-cellulose combination) was always used. The ratios were, however, varied.
[0086] With the above formulation (see Table 3), different medium-viscosity hydroxyethyl celluloses (HEC) were, on the one hand, used in dispersion paints (analogous to paint formulation 1), and the thus resulting viscosities were compiled. As pointed out in the description, the medium-viscosity HECs were classified via the determination of the viscosity of 2% solutions and denoted as such.
[0000]
TABLE 4
Results of the stirring in of medium-viscosity celluloses
Paint variant I
Viscosity Stormer viscometer
Medium-viscosity HEC
after 24 h storage at 25° C.
HEC 4,650
94.1 KU
HEC 16,500
100.2 KU
HEC 28,800
104.2 KU
HEC 49,000
108.1 KU
[0087] In a further step, dispersion paints were produced on the basis of different ratios of combination of a high-viscosity HEC (HEC 103,000) with starch, the addition of starch having taken place with the starch portions indicated below, on the one hand at the beginning (analogous to paint variant II) and, on the other hand, only at the end of the formulation (analogous to paint variant III).
[0000]
TABLE 5
Results of the viscosities of cellulose/starch combinations in
dispersion paints (paint formulations II and III).
Starch portion in the
combination with HEC
Paint variant II (early
Paint variant III
103,000
addition of starch)
(late addition of starch)
60% starch
—
95.3 KU
50% starch
94.1 KU
100.2 KU
40% starch
97.7 KU
104.5 KU
30% starch
102.0 KU
107.2 KU
20% starch
106.3 KU
108.7 KU
15% starch
108.2 KU
—
[0088] Diagram 1: Comparison of the Viscosities of Dispersion Paints Based on Starch/High-Viscosity Cellulose Combinations Relative to the Pure Use of Medium-Viscosity Cellulose
[0089] The diagram indicates what portions of starch in combination with a high-viscosity HEC can be introduced into a paint system to achieve the thickening performances of pure medium-viscosity celluloses.
[0090] It is, thus, feasible to replace a HEC 4,650 with 50% portions of starch of a pigment thickener combination at an early addition, and with about 60% at a later addition. HEC 16,500 can be substituted by about 65% high-viscosity cellulose and a 35% portion of starch at an early addition, and by about 50% high-viscosity cellulose and 50% starch at a later addition. A HEC 28,800 viscosity in the paint corresponds to a combination with about 25% at an early, and about 40% at a later, addition. A HEC 49,000 can be replaced with portions of 15% starch at an early, and about 20% starch at a late, addition.
a) Comparison of paint properties of dispersion paints thickened with HEC and HEC/starch, respectively.
[0092] Three different paints were prepared using the interior dispersion paint formulation described in Table 3:
a) a paint (paint IV) with a HEC 49,000 thickener; b) a paint (paint V) using a high-viscosity HEC 103,000 in combination with a starch (starch A type) at a ratio of 74/26; and c) for comparison, a paint (paint VI) with pure high-viscosity HEC 103,000, yet only that portion which is used in the combination (0.34%).
[0000]
TABLE 6
Comparison of interior dispersion paints, including
application-specific tests (leveling, sagging, scrubbing, roll test)
Paint IV
HEC 103,000/
starch A
Paint V
Paint VI
Interior dispersion paint
74/26
HEC 49,000
HEC 103,000
Partial amount of use %
0.34/0.11
0.45
0.34
Total amount of use %
0.45
0.45
0.34
Brookfield [mPa · s];
8,800
8.300
5,700
20 rpm
Stormer viscosity [KU]
108
108
92
Leveling (Leneta; ASTM
8
6
8
D 4062-99)
Sagging ASTM D4400-
14
14
10
99 [mils]
Scrub class (ISO 11998)
3
3
3
Roll test*
+++
++
++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++), good (++), acceptable (+), poor (−)
[0096] As is apparent from Table 6, the properties of a paint based on pure medium-viscosity HEC 49,000 (paint V) have definitely been achieved through the combined use of starch A/HEC. In addition, improvements have been demonstrated in terms of leveling (8 rather than 6 mils) and roll behavior. A comparison with a paint just produced with the portion of HEC (paint VI) used in the combination (0.34% in paint IV) does not yield the desired viscosities and also exhibits poorer sagging values and a tougher roll behavior. Thus, also improved paint properties will be achieved by the dispersion paints produced on the basis of the paint thickener combination (starch/cellulose).
a) Comparison of paint properties of dispersion paints thickened with MC and MC/starch, respectively.
[0098] With the interior dispersion paint formulation described in Example 2, two further paints were produced:
a) a paint (paint VII) with methyl cellulose (MC) 22,500; and b) a paint (paint VIII) using a high-viscosity MC 78,000 in combination with a starch (starch B type; epichlorohydrin cross-linked carboxymethylated amylopectin potato starch; SD (CMS) ˜0.33) at a ratio of 60/40.
[0000]
TABLE 7
Comparison of interior dispersion paints, including
application-specific tests (leveling, sagging, scrubbing, roll test).
Paint VIII
MC 78,000/starch B
Paint VII
60/40
Interior dispersion paint
MC 22,500
Late addition of starch
Partial amount of use %
—
0.27/0.18
Total amount of use %
0.45
0.45
Brookfield [mPa · s]; 20 rpm
8,160
8,460
Stormer viscosity [KU]
106.6
106.2
Leveling (Leneta; ASTM D
8
9
4062-99)
Sagging ASTM
14
14
D4400-99 [mils]
Scrub class (ISO 11998)
3
3
Roll test*
++
++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++), good (++), acceptable (+), poor (−)
[0101] It is apparent from Table 7 that, in general, the properties of a paint based on pure medium-viscosity MC 22,500 (paint VII) are achieved through the combined use of starch B and MC 78,000. Improvements in terms of leveling (9 rather than 8) and roll behavior have again been demonstrated. Thus, enhanced paint properties will again be achieved with the dispersion paints produced on the basis of the paint thickener combination (starch/cellulose).
Example 3
Use of Starch-Cellulose Combinations in Dispersion Paints
[0102] Formulation of a further interior dispersion paint by way of examples with cold-water-soluble octenyl-succinylated amylopectin potato starch (starch C) and cold-water-soluble propionaldehyde cross-linked conventional potato starch (starch D):
a) Paint IX: dispersion paint with pure cellulose 16,500 thickener; b) Paints X+XI: dispersion paint using starch/cellulose with the addition of starch after the binder.
[0000]
TABLE 8
Batch formulations for dispersion paints with and
without starch addition
Material
Description
Paint IX
Paint X
Paint XI
H 2 O (deionized water)
solvent
377.3
377.3
377.3
Cellulose HEC 16,500
thickener
5.0
—
—
Cellulose HEC
thickener
—
3.0
3.0
103,000
NaOH 25%
Base
0.2
0.2
0.2
Coatex
wetting
3.5
3.5
3.5
agent
Agitan 285
defoamer
2
2
2
Socl P2
Filler
150
150
150
Omyacarb 5-GU
Filler
400
400
400
Mergal K15
biocide
2
2
2
Acronal LR 8961
binder
60
60
60
Starch C
thickener
—
2
—
Starch D
thickener
—
—
2
Total
1000
g
1000
g
1000
g
[0105] Execution:
[0106] Deionized water is provided, the cellulose is stirred in for 5 min and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, fillers and biocide is effected. Following a dispersion phase of 10 minutes, the binder is introduced, followed by the addition of starch for paints X and XI. After 10 minutes of stirring, the paint is stored, and the viscosity and pH are determined after 24 h, and further paint examinations are made regarding the paint quality.
[0000]
TABLE 9
Comparison of interior dispersion paints, including
application-specific tests (levelling, sagging, scrubbing, roll test).
Interior dispersion paint
Paint X
Paint XI
HEC
HEC
Paint IX
103,000/
103,000/
HEC
starch C
starch D
16,500
60/40
60/40
Partial amount of use %
−
0.30/0.20
0.30/0.20
Total amount of use %
0.50
0.50
0.50
Brookfield [mPa · s]; 20 rpm
7,100
9,760
10,580
Stormer viscosity [KU]
106.3
115.4
110.2
Leveling (Leneta; ASTM D 4062-99)
4
4
4
Sagging ASTM D4400-99 [mils]
12
14
14
Roll test*
++
+++
+++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++),
good (++),
acceptable (+),
poor (−)
[0107] The 60/40 HEC-starch thickener combinations yield very good thickener performances over pure HEC 16,500 paints. The paint properties differ scarcely. Slight advantages over the pure HEC paint (paint IX) were observed with paints X (starch C) and paint XI (starch D) regarding the sagging and roll properties.
Example 4
Use of Starch-Cellulose Combinations in Exterior Dispersion Paints
[0108] Formulation of an exterior dispersion paint by way of examples using starches (starch A and starch B):
a) Paint XII: Dispersion paint with pure cellulose thickener (HEC 28,800); and b) Paints XIII and XIV: Dispersion paints using starch/cellulose with the addition of starch after the binder.
[0000]
TABLE 10
Batch formulations for dispersion paints with and without starch addition
Material
Description
Paint XII
Paint XIII
Paint XIV
H 2 O (Deionized water)
solvent
160
160
160
Cellulose HEC 28,800
thickener
3.4
—
—
Cellulose HEC
thickener
—
2.0
2.0
103,000
NaOH 25%
base
0.4
0.4
0.4
Coatex
wetting
1.5
1.5
1.5
agent
Agitan 315
defoamer
1.5
1.5
1.5
Preventol D6
biocide
1.2
1.2
1.2
Kronos 300
pigment
75
75
75
Finntalc M 20 SL
filler
52
52
52
Omyacarb 15-GU
filler
117
117
117
Omyacarb 5-GU
filler
113
113
113
Acronal S 559
binder
225
225
225
Starch A
thickener
—
1.4
—
Starch B
thickener
—
—
1.4
Total
750 g
750 g
750 g
[0111] Execution:
[0112] Deionized water is provided, the cellulose is stirred in for 5 minutes and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, biocide, pigments and fillers is effected. Following a dispersion phase of 20 minutes, the binder is introduced, followed by the addition of starch for paints XIII and XIV. After 10 minutes of stirring, the paint is stored, and the viscosity and pH are determined after 24 h.
[0000]
TABLE 11
Comparison of exterior dispersion paints, including application-
specific tests (leveling, sagging, scrubbing, roll test).
Exterior dispersion paint
Paint XIII
Paint XIV
HEC
HEC
Paint XII
103,000/
103,000/
HEC
starch A
starch B
28,800
60/40
60/40
Partial amount of use %
—
0.27/0.18
0.27/0.18
Total amount of use %
0.45
0.45
0.45
Brookfield [mPa · s]; 20 rpm
6,240
7,340
7,380
Stormer viscosity [KU]
99.2
100.4
100.3
Leveling (Leneta; ASTM D 4062-99)
5
5
6
Sagging ASTM D4400-99 [mils]
10
12
10
Scrub Class (ISO 11998)
2
2
2
Roll test*
++
+++
+++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++),
good (++),
acceptable (+),
poor (−)
[0113] The 60/40 HEC-starch thickener combinations yield very good thickener performances over pure HEC 28,800 paints. The paint properties differ scarcely. Slight advantages over the pure HEC paint (paint XII) were observed with paint XIII (starch A) in terms of sagging, and with paint XIV (starch B) in terms of leveling, and with both of the two starch-containing paints regarding the roll properties.
Example 5
[0114] Further comparisons were made analogously to Examples 2 and 2.1, of interior paints produced, on the one hand, with celluloses, concretely methyl celluloses (MC) and ethyl celluloses (EC), and, on the other hand, with cellulose (MC, EC)-starch combinations.
[0115] Formulation of the interior dispersion paint analogous to the Examples paint I, paint II and paint III:
[0116] 5.1. Comparison of Thickener Performances at Different Use Ratios of Methyl Cellulose/Starch and at Different Starch Addition Times, Respectively.
[0117] In the following dispersion paints produced, the same total amount of thickener (cellulose, starch-cellulose combination) was always used. The ratios were, however, varied.
[0118] With the formulation indicated above (see Table 3), different medium-viscosity methyl hydroxyethyl celluloses (MC) were, on the one hand, used in dispersion paints (analogous to paint formulation I), and the thus resulting viscosities were compiled. As pointed out in the description, the medium-viscosity MCs were classified via the determination of the viscosity of 2% solutions and denoted as such.
[0000]
TABLE 12
Results of the stirring in of medium-viscosity celluloses
Paint variant I
Stormer viscometer viscosity
Medium-viscosity MC
after 24 h storage at 25° C.
MC 4,000
92.0 KU
MC 10,000
99.0 KU
[0119] In a further step, dispersion paints were produced on the basis of different ratios of combination of a high-viscosity MC (MC 138,000) with starch, the addition of starch having taken place with the starch portions indicated below, on the one hand, at the beginning (analogous to paint variant II) and, on the other hand, only at the end of the formulation (analogous to paint variant III).
[0000]
TABLE 13
Results of the viscosities of MC/starch A combinations in dispersion paints
(paint formulations II and III).
Starch portion starch
A in the combination
Paint variant II (early
Paint variant III
with MC 138,000
addition of starch)
(late addition of starch)
60% starch
—
98.8 KU
50% starch
97.5 KU
102.0 KU
40% starch
104.3 KU
106.0 KU
30% starch
108.2 KU
109.5 KU
22% starch
111.0 KU
112.0 KU
[0120] Diagram 2: Comparison of the viscosities of dispersion paints based on starch/high-viscosity MC combinations relative to the pure use of medium-viscosity MCs:
[0121] The diagram indicates what portions of starch in combination with a high-viscosity MC 138,000 can be introduced into a paint system to achieve the thickening performances of pure medium-viscosity celluloses.
[0122] It is, thus, feasible to replace an MC 4,000 with 55% portions of starch of a pigment thickener combination at an early addition, and with about 65% at a late addition. MC 10,000 can be substituted by about 55% high-viscosity MC and a 45% portion of starch at an early addition, and by about 45% high-viscosity MC and 55% starch at a late addition.
a) Comparison of thickener performances at different use ratios of ethyl hydroxyethyl cellulose/starch and at different starch addition times, respectively.
[0124] In the following dispersion paints produced, the same total amount of thickener (cellulose, starch-cellulose combination) was always used. The ratios were, however, varied.
[0125] With the formulation indicated above (see Table 3), different medium-viscosity ethyl hydroxyethyl celluloses (EC) were, on the one hand, used in dispersion paints (analogous to paint formulation 1), and the thus resulting viscosities were compiled. As pointed out in the description, the medium-viscosity MCs were classified via the determination of the viscosity of 2% solutions and denoted as such.
[0000]
TABLE 14
Results of the stirring in of medium-viscosity celluloses.
Paint variant I
Stormer viscometer viscosity
Medium-viscosity EC
after 24 h storage at 25° C.
EC 4,700
89.7 KU
EC 22,600
102.2 KU
[0126] In a further step, dispersion paints were produced on the basis of different ratios of combination of a high-viscosity EC (EC 75,000) with starch, the addition of starch having taken place with the starch portions indicated below, on the one hand, at the beginning (analogous to paint variant II) and, on the other hand, only at the end of the formulation (analogous to paint variant III).
[0000]
TABLE 15
Results of the viscosities of EC/starch A combinations in dispersion paints
(paint formulations II and III).
Starch portion starch
A in the combination
Paint variant II (early
Paint variant III
with EC 75,000
addition of starch)
(late addition of starch)
60% starch
85.7 KU
—
50% starch
90.4 KU
95.1 KU
40% starch
95.7 KU
100.4 KU
30% starch
99.1 KU
103.7 KU
[0127] Diagram 3: Comparison of the viscosities of dispersion paints based on starch/high-viscosity EC combinations relative to the pure use of medium-viscosity EC:
[0128] The diagram indicates what portions of starch in combination with a high-viscosity EC 75,000 can be introduced into a paint system to achieve the thickening performances of the pure medium-viscosity ethyl hydroxyethyl celluloses.
[0129] It is, thus, feasible to replace an EC 4,700 with 50% portions of starch of a pigment thickener combination at an early addition, and with about 55% at a late addition. The EC 22,600 can be substituted by about 80% high-viscosity EC and a 20% portion of starch at an early addition, and by about 65% high-viscosity EC and 35% starch at a late addition.
Example 6
Use of Starch-Cellulose Combinations in Dispersion Paints
[0130] Formulation of a further interior dispersion paint by way of examples, using an epichlorohydrine cross-linked carboxymethyl corn starch (starch E), a carboxymethyl potato starch (starch F), a propoxylated potato starch (G) and a cross-linked propoxylated potato starch (H):
a) Paint XV: Dispersion paint with pure HEC 4,650 thickener; and b) Paints XVI+XVII+XVIII+XIX: Dispersion paint using starch/cellulose and the addition of the starch shortly after the cellulose.
[0000]
TABLE 16
Batch formulations for dispersion paints with and without starch addition
Paint
Material
Description
XV
XVI
XVII
XVIII
XIX
H 2 O (deionized water)
solvent
343.5
343.5
343.5
343.5
343.5
Cellulose HEC 4,650
thickener
4.5
—
—
—
—
Cellulose HEC
thickener
—
2.7
2.7
2.7
2.7
103,000
Starch E
thickener
—
1.8
—
—
—
Starch F
thickener
—
—
1.8
—
—
Starch G
thickener
—
—
—
1.8
Starch H
thickener
—
—
—
—
1.8
NaOH 25%
base
0.5
0.5
0.5
0.5
0.5
Coatex
wetting agent
3.0
3.0
3.0
3.0
3.0
Agitan 285
defoamer
2.0
2.0
2.0
2.0
2.0
Kronos 2190
pigment
100
100
100
100
100
Finntalc M 30 SL
filler
70
70
70
70
70
Omyacarb 5-GU
filler
125
125
125
125
125
Omyacarb 2-GU
filler
250
250
250
250
250
Mergal K15
biocide
1.5
1.5
1.5
1.5
1.5
Acronal LR 8961
binder
100
100
100
100
100
Total
1000 g
1000 g
1000 g
1000 g
1000 g
[0133] Execution:
[0134] Deionized water is provided, the cellulose is stirred in for 5 minutes, the starch is stirred in for XVI to XIX and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, pigments, fillers and biocide is effected. Following a dispersion phase of 5 minutes, the binder is introduced and stirred for another 3 minutes. Subsequently, storage takes place for 24 hours, followed by viscosity measurements, pH determinations and further paint examinations regarding additional quality criteria.
[0000]
TABLE 17
Comparison of interior dispersion paints, including application-specific tests
(leveling, sagging, roll test).
XV
XVI
XVII
XVIII
XIX
Interior dispersion paint
HEC 4.650
Starch E
Starch F
Starch G
Starch H
Partial amount of use %
—
2.8/1.7
2.8/1.7
2.8/1.7
2.8/1.7
HEC 103,000/Starch
Total amount of use %
4.5
4.5
4.5
4.5
4.5
Brookfield [mPa · s]; 20 rpm
5450
6850
6400
6200
7300
Stormer viscosity [KU]
98.5
100.0
98.2
96.2
99.4
pH Wert
9.0
9.1
9.0
9.0
9.0
Leveling (Leneta; ASTM D 4062-
8
9
8
9
9
99
Sagging ASTM D4400-99
12
14
12
12
12
[mils]
Roll test*
++
+++
+++
++
++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++),
good (++),
acceptable (+),
poor (−)
[0135] The 60/40 HEC-starch thickener combinations yield very good thickener performances over pure HEC 4,650 paints. The paint properties differ scarcely. Slight advantages over the pure HEC paint (paint XV) were observed with paints XVI and XVII in the roll test, as well as with XVI also in terms of sagging and leveling. By contrast, starch paints XVIII and XIX exhibited advantages in leveling over the pure HEC paint.
Example 7
Use of Starch-Cellulose Combinations in Dispersion Paints
[0136] Formulation of a further interior dispersion paint by way of examples, using a cold-water-soluble acetylated potato starch (starch 1), a cold-water-soluble octenylsuccinylated potato starch (starch J) and a cold-water-soluble potato starch (K):
a) Paint XX: Dispersion paint with pure HEC 28,800 thickener; and b) Paints XXI+XXII+XXIII: Dispersion paint using starch/cellulose with the addition of the starch shortly after the cellulose.
[0000]
TABLE 18
Batch formulations for dispersion paints with and
without starch addition.
Paint
Material
Description
XX
XXI
XXII
XXIII
H 2 O (deionized
solvent
343.5
343.5
343.5
343.5
water)
Cellulose HEC
thickener
4.5
—
—
—
28.800
Cellulose HEC
thickener
—
2.25
2.25
2.25
103.000
Starch I
thickener
—
2.25
—
—
Starch J
thickener
—
—
2.25
—
Starch K
thickener
—
—
—
2.25
NaOH 25%
base
0.5
0.5
0.5
0.5
Coatex
wetting agent
3.0
3.0
3.0
3.0
Agitan 285
defoamer
2.0
2.0
2.0
2.0
Kronos 2190
pigment
100
100
100
100
Finntalc
filler
70
70
70
70
M 30 SL
Omyacarb 5-GU
filler
125
125
125
125
Omyacarb 2-GU
filler
250
250
250
250
Mergal K15
biocide
1.5
1.5
1.5
1.5
Acronal
binder
100
100
100
100
LR 8961
Total
1000 g
1000 g
1000 g
1000 g
[0139] Execution:
[0140] Deionized water is provided, the cellulose is stirred in for 5 min, the starch is stirred in for XXI, XXII and XXIII and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, pigments, fillers and biocide is affected. Following a dispersion phase of 5 min, the binder is introduced and stirred for another 3 minutes. Subsequently, storage takes place for 24 hours, followed by viscosity measurements, pH determinations and further paint examinations regarding additional quality criteria.
[0000]
TABLE 19
Comparison of interior dispersion paints, including application-
specific tests (leveling, sagging, scrub class, roll test).
Interior dispersion paint
XX
HEC
XXI
XXII
XXIII
28,800
Starch I
Starch J
Starch K
Partial amount of use %
—
2.25/2.25
2.25/2.25
2.25/2.25
HEC 103,000/Starch
Total amount of use %
4.5
4.5
4.5
4.5
Brookfield [mPa · s];
7,450
7,250
8,350
9,800
20 rpm
Stormer viscosity [KU]
104.6
100.9
104.2
102.7
pH
9.0
8.9
9.0
9.0
Levelling (Leneta; ASTM
9
9
9
9
D 4062-99)
Sagging ASTM D4400-99
8
10
10
10
[mils]
Scrub class (ISO 11998)
3
3
3
3
Roll test*
++
+++
+++
+++
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++),
good (++),
acceptable (+),
poor (−)
[0141] The 50/50 HEC-starch thickener combinations yield very good thickener performances over pure HEC 28,800 paints. The paint properties differ scarcely. A welcome improvement over the pure HEC paint (paint XX) was again achieved with the starch paints as regards sagging and the roll behavior.
Example 8
Use of Starch-Cellulose Combinations in Paints Based on Water Glass/Dispersion Binder
[0142] Formulation of an interior dispersion silicate paint by way of examples, using starch A (epichlorohydrine cross-linked CM potato starch):
a) Paint XXIV: Dispersion silicate paint with pure hydroxy-ethyl cellulose (HEC 12,000); and b) Paint XXV: Dispersion paint using starch/cellulose.
[0145] Addition of starch (starch A) shortly after cellulose.
[0000]
TABLE 20
Batch formulations for the dispersion paints with and without starch
addition.
Material
Description
Paint XXIV
Paint XXV
H 2 O (deionized water)
solvent
320.2
320.2
Cellulose HEC 12,000
thickener
2.0
—
Cellulose HEC 60,000
thickener
—
1.0
Starch A
thickener
—
1.0
Betolin V30
xanthane
0.8
0.8
Sapetin D27
wetting agent
3.0
3.0
Betolin Quart 25
stabilizer
4.0
4.0
Kronos 2190
pigment
65
65
Agitan 280
defoamer
2
2
Omyacarb 5-GU
filler
200
200
Omyacarb 2-GU
filler
100
100
Finntalc M30SL
filler
65
65
Acronal S559
binder
70
70
Betolin P35
water glass
160
160
Betolin A11
viscosity stabilizer
8
8
Total
1000 g
1000 g
[0146] Execution:
[0147] Deionized water is provided, the cellulose is stirred in for 5 minutes, the starch is also stirred in for XXV, followed by the addition of Betolin V30. After this, Sapetin D27 and Quart 25 are added, and the batch is homogenized. Subsequently, Kronos 2190, the defoamer and the fillers are added. Following a short dispersion phase (5 minutes), the dispersion binder, water glass and viscosity stabilizer are introduced and homogenized for 5 minutes. Subsequently, storage takes place for 24 hours, followed by viscosity measurements, pH determinations and further viscosity measurements after storage at 50° C., as well as a roll test.
[0000]
TABLE 21
Comparison of interior dispersion silicate paints, viscosity
development over a month at RT and 50° C., respectively.
Interior dispersion silicate paint
Paint XXV
HEC 60,000/
Paint XXIV
starch A
HEC 12,000
50/50
Brookfield [mPa · s]; 20 rpm 24 h
3,000
2,950
Roll test*
++
+++
Storage
RT
50° C.
RT
50° C.
Brookfield [mPa · s]; 20 rpm; 14 d
4,800
8,750
4,950
8,700
Brookfield [mPa · s]; 20 rpm; 28 d
8,650
9,350
9,300
9,150
PH
11.2
11.2
*subjective evaluation of rolling using roller with lamb's wool cover
very good (+++),
good (++),
acceptable (+),
poor (−)
[0148] The paints thickened both with pure HEC 12,000 and with the HEC 60,000/starch A combination exhibit very similar viscosities and viscosity developments at extended storage. 50% starch can be introduced into this combination without suffering viscosity losses.
Example 9
Use of Starch-Cellulose Combinations in Textured Plaster Based on Water Glass/Dispersion Binder
[0149] Formulation of a silicate textured plaster by way of examples, using starch A (epichlorohydrine cross-linked CM potato starch):
a) Plaster XXVI: Silicate textured plaster with pure hydroxy ethyl cellulose (HEC 12,000) b) Plaster XXVII: Silicate textured plaster using starch/cellulose
[0152] Addition of starch (starch A) shortly after cellulose
[0000]
TABLE 22
Batch formulations for the silicate textured plasters with and without
starch addition.
Plaster
Material
Description
Plaster XXVI
XXVII
H 2 O (deionized water)
solvent
104.2
104.2
Cellulose HEC 12,000
thickener
2.0
—
Cellulose HEC 60,000
thickener
—
1.0
Starch A
thickener
—
1.0
Betolin V30
xanthane
0.8
0.8
Sapetin D27
wetting agent
3.0
3.0
Betolin Quart 25
stabilizer
2.0
2.0
Kronos 2190
pigment
30
30
Agitan 280
defoamer
2
2
Carolith 0-0.2 mm
granulate
210
210
Carolith 0.2-0.5 mm
granulate
180
180
Carolith 0.5-1 mm
granulate
110
110
Carolith 1.5-2 mm
granulate
50
50
Carolith 2.5-3 mm
granulate
70
70
Finntalc M30SL
filler
65
65
Acronal S559
binder
85
85
Betolin P35
water glass
70
70
Betolin A11
viscosity stabilizer
8
8
Betolin AH 250
hydrophobing agent
8
8
Total
1000 g
1000 g
[0153] Execution:
[0154] Deionized water is provided, the cellulose is stirred in for 5 minutes, the starch is also stirred in for XXVII, followed by the addition of Betolin V30. After this, Sapetin D27 is added, and the batch is homogenized. Then follow the addition of Kronos 2190 and Quart 25 and a further 5-minute stirring step. After the addition of the defoamer, fillers and two finer granulates, the batch is again homogenized. After this, half of the dispersion binder, the water glass and the viscosity stabilizer are added. Following a short dispersion phase, the remaining granulates, the second partial amount of the dispersion and the hydrophobing agent are added. Then follow immediate measurements of the viscosity and the spreading index as well as an evaluation of the mounting behavior.
[0000]
TABLE 23
Comparison of textured silicate plasters, viscosities, spreading index,
mounting behavior and pH values.
Textured silicate plaster
Plaster XXVII
Plaster XXVI
HEC 60,000/starch
HEC 12,000
A 50/50
Brookfield [mPa · s]; 20 rpm
50,000
50,000
immediately
Spreading index [cm] immediately
20.3
20.9
Mounting behavior*
++
+++
Brookfield [mPa · s]; 20 rpm 24 h
70,000
75,000
Spreading index [cm] 24 h
20.2
20.3
pH
11.2
11.2
*subjective evaluation of spreading behavior
very good (+++),
good (++),
acceptable (+),
poor (−)
[0155] The textured plasters thickened both with pure HEC 10,000 and with the HEC 60,000/starch A combination exhibit very similar viscosities, spreading index values. The mounting behavior of the starch plaster could be enhanced by the starch.
Example 10
Use of Starch-Cellulose Combinations in a 1.5-2 mm Resin Plaster
[0156] Formulation of a dispersion-binder-based resin plaster by way of examples, using starch A (epichlorohydrine cross-linked CM potato starch):
a) Plaster XXVIII: Resin plaster with pure hydroxyethyl cellulose (HEC 12,000). b) Plaster XXIX: Resin plaster using starch/cellulose.
[0159] Addition of starch (starch A) shortly after cellulose.
[0000]
TABLE 24
Batch formulations for the resin plasters with and without starch
addition.
Material
Description
Plaster XXVIII
Plaster XXIX
H 2 O (deionized water)
solvent
63.3
63.3
Cellulose HEC 12,000
thickener
1
—
Cellulose HEC 60,000
thickener
—
0.5
Starch A
thickener
—
0.5
NaOH (25% ig)
base
3
3.0
Sapetin D25
wetting agent
1
1
Kronos 2190
pigment
20
20
Finntalc M30SL
filler
60
60
Omyacarb 10GU
filler
220
220
Nopco 8034
defoamer
1.7
1.7
Mergal K15
preservation
1.0
1.0
Carolith 0-0.2 mm
granulate
80
80
Carolith 1-1.5 mm
granulate
186
186
Carolith 1.5-2 mm
granulate
263
263
Acronal S559
binder
100
100
Total
1000 g
1000 g
[0160] Execution:
[0161] Deionized water is provided, the cellulose is stirred in for 5 minutes, the starch is stirred in for XXIX and subsequently thickened with soda lye. After this, the stirring in of the wetting agent, defoamer, pigments, fillers, biocide and half of the binder is affected. Following a dispersion phase of 5 minutes, the granulates and the residual binder are introduced and stirred for another 3 minutes. Then follow immediate measurements of the viscosity, the spreading index and an evaluation of the mounting behavior as well as measurements of the viscosity and of the spreading index after 24 hours.
[0000]
TABLE 25
Comparison of resin plasters, viscosities, spreading index, mounting
behavior and pH values.
Dispersion-bound resin plaster
Plaster XXIX
Plaster XXVIII
HEC 60,000/starch
HEC 12,000
A 50/50
Brookfield [mPa · s]; 20 rpm
130,000
140,000
immediately
Spreading index [cm] immediately
17.0
16.9
Mounting behavior*
+
++
Brookfield [mPa · s]; 20 rpm 24 h
200,000
220,000
Spreading index [cm] 24 h
17.1
16.9
PH
9.0
9.0
*subjective evaluation of spreading behavior
very good (+++),
good (++),
acceptable (+),
poor (−)
[0162] The textured plasters thickened both with pure HEC 12,000 and with the HEC 60,000/starch A combination exhibit very similar viscosities and spreading index values. 50% starch can be introduced into this combination without suffering viscosity losses. The plaster admixed with starch again shows a very good mounting behavior.
|
Starch(es) and starch derivatives are combined together with at least one high-viscosity cellulose as a thickener in dispersion binder-based color systems. The cellulose has a viscosity of >50,000 mPa·s, measured by the Brookfield rotation viscometer as a 2% swollen aqueous solution at 5 rpm and 25° C. A method produces dispersion binder-based color systems and a dispersion color thickener combination and a dispersion color containing the dispersion color thickener combination.
| 2
|
TECHNICAL FIELD
[0001] The present disclosure relates generally to multi-phase, multi-fluid flow and, more particularly, to computer-implemented methods for simulating fluid flow in subterranean formations, e.g., during the completion, stimulation, fracturing or enhancement of a well or the production of fluids from the well.
BACKGROUND
[0002] Multi-phase, multi-fluid flow in a porous media is a problem of great practical importance in a variety of natural physical processes, as well as a host of industrial applications, such as in petroleum engineering and medical engineering, among many others. Fluid displacement occurs when temporal sequences of different fluids interact with each other, and is characterized by the movement of the interface or front between the fluids. The present disclosure describes and analyzes a new practical and efficient fluid displacement simulator with sound physics, mathematical formulations, and numerical discretization, which is applicable to simulate the miscible fluid displacement in large scale integrated wellbore-reservoir (IWR) systems.
[0003] The present disclosure attempts to address two major challenges with properly simulating the multi-phase, multi-fluid flow phenomena in petroleum engineering. One of the major challenges involves enhanced oil recovery and enabling a practical and an economical multi-fluid displacement model that can capture the two most prominent characteristics, namely, the length of the mixing zone and the front characteristics of the displaced fluid by accounting for mainly convection, diffusion, viscosity difference, density difference, and surface tension among other parameters such as difference in temperature conduction coefficients and the like. Existing models for the fluid displacement in reservoir stimulation treat the phenomenon like piston displacement. This simplified method is relatively easy to implement and this commonly used, yet it is based on the assumption that fluids in placement processes have some additional physical properties such that there are no diffusion processes or interfaces between the fluids, which in many instances, is not physically correct. The Buckley-Leverett type approach is one of the improved models for immiscible fluid displacement, yet its basic governing equation cannot be rigorously justified because the curvature of the fluid-fluid interface is expressed as the square root of the permeability of the porous media, which is oftentimes not the case. A reduced one-dimension scalar convective-diffusive model for this case is proposed in International Patent Application No. PCT/US2014/015882 filed by Wu et al., where an effective diffusion coefficient and a retarding convective factor are introduced to better and more physically correctly consider the effects on the miscible fluid displacement from the convection and advection, viscosity difference, and density difference.
[0004] The second major challenge is accurately predicting the multi-fluid flow dynamics in an IWR system with high numerical stability features. The accurate prediction of fluid displacement is essential to locating the acid fronts of the hydrocarbons during matrix production enhancement. This task involves the coupling of high wellbore flows, low flows in the reservoir, and the fluid front tracking; all are tightly coupled in a computational implicit approach. The modeling of these fluid displacement processes requires the Navier-Stokes (NS) equations to describe the fluid dynamics in the wellbore, Darcy equations to properly model the porous media flow in the reservoir, as well as a fluid displacement model to capture the fluid front dynamics and the mixing zone size. These mathematically partial differential equations are different in each sub-region of the flow domain of interest and thus must be connected through suitable connection conditions that describe the fluid flow across the permeable interface, where the fluid flows between the wellbore and the reservoir are coupled. Mathematical difficulty arises from Darcy equations containing the pressure's second-order derivatives and velocity's first-order derivative—while it is the other way around in the NS system—and a lack of coupling equations for the scalar, which is used in a convection-diffusion model to characterize the fluid displacement process. Therefore, the fluid transport in such coupled systems has received detailed attention, both from the mathematical and numerical point of view and it was recently extended to open-hole completion systems. The extension includes coupling mechanisms of hybrid NS and Darcy's systems, where the mass and pressure continuity at the junction points, and that velocity or pressure at junctions, is modeled by Darcy's law. However, it appears that the fluid displacement dynamics in any completion system have not been reported yet.
[0005] A second order upwind renormalization (SOUR) scheme to simulate a multi-fluid displacement process in a vertical wellbore open-hole completion system is described in detail below. The overall methodology includes coupling mechanisms to describe scalar, velocity, and pressure variables at the junction points, numerical simulation approaches to solve different systems of the specific governing partial differential equations in each domain, and geometrical modeling of open-hole completion systems. The numerical algorithm made the simulation of the fluid displacement process in any completion system stable, accurate, fast, feasible, efficient, and simple to use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
[0007] FIG. 1 is a schematic diagram of miscible fluid displacement in an open-hole vertical well completion system for bullheading;
[0008] FIG. 2 illustrates a computational grid arrangement for the variables in miscible fluid displacement;
[0009] FIG. 3 illustrates a comparison of method of manufactured solution (MMS) for test functions ofu=xt, p=xt, and c=xt in the wellbore and u=rt, p=rt, and c=rt in the reservoir at time t=1.49;
[0010] FIG. 4 illustrates a comparison of MMS for test functions of u=xt, p=t cos(πx), and c=xt in the wellbore and u=rt, p=t cos(πr), and c=rt in the reservoir at time t=1.49;
[0011] FIG. 5 illustrates the compressibility effects on the fluid density in the reservoir at t=10.59.;
[0012] FIG. 6 illustrates the concentration distributions along the wellbore and the reservoir of shown case at t=2000.0; and
[0013] FIG. 7 illustrates the pressure distributions along the wellbore and the reservoir of shown case at t=2000.0;
[0014] FIG. 8 illustrates the velocity distributions along the wellbore and the reservoir of shown case at t=2000.0;
[0015] FIG. 9 illustrates the viscosity distributions along the wellbore and the reservoir of shown case at t=2000.0;
[0016] FIG. 10 illustrates (a) the velocity, (b) concentration, and (c) pressure distributions along the wellbore and the reservoir at t=2.49 sec and a Reynolds number of 10,000.
DETAILED DESCRIPTION
[0017] Illustrative embodiments of the present disclosure are described in detail herein. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation specific decisions must be made to achieve developers' 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 the present disclosure. Furthermore, in no way should the following examples be read to limit, or define, the scope of the disclosure.
[0018] The present disclosure presents a new numerical methodology and computational solver for multi-fluids and/or multiphase flows to describe integrated wellbore-reservoir multiphase (IWRM) petrophysics. The wellbore's high-velocity flow continuously interacts with the reservoir's relative low-velocity (Darcy-like) flow, especially around the perforation regions. Fast flows are adequately described by the unsteady Navier-Stokes (NS) equations, while slow flows are often modeled using the unsteady Darcy equations. The fluids' miscible displacement model is given by the unsteady convection-diffusion process for fluid interface tracking. The computational methods for solving the governing partial differential equations (PDEs) must be stable, consistent and computationally efficient, with the objective of obtaining relevant solutions using adequate and simple to implement numerical schemes. The present disclosure sets forth the governing equations of the IWR system, new fluid junction condition formulations, and a new spatial second-order stable finite difference formulation that enables solving implicitly the model's equations.
[0019] Extending these new formulations to multi-physics fluids systems naturally enables the coupling of the wellbore's NS equations with the reservoir's porous media Darcy equations through the physical connection conditions applied at the flow's junction zones. The currently used connection conditions models are of a shared scalar value type, implemented for the pressure, interface's concentration, density, and viscosity. These relationships ensure the flow's mass continuity and momentum conservation for the coupled wellbore and reservoir flows. For a one-dimensional (1D) case, the flow loss occurs at an infinitesimally small area, resulting in a mathematical singularity, which is relieved in the current methodology by using a double nodes formulation. The staggered scheme couples the pressure and velocity variables, while the velocity, concentration, density, and viscosity variables are collocated. The numerical stability of the convection terms is accomplished by using the novel second-order upwind renormalization (SOUR) scheme, which uses the original governing equation to generate second-order accurate terms in the Taylor series expansion. The standard second-order upwind (SOU) scheme cannot be used near the boundaries; thus, the novel SOUR scheme was enhanced to be applicable at all discrete points in the flow domain.
[0020] The simulation is validated by using the method of manufactured solution (MMS). The results demonstrate that for the first time, the formulation and numerical scheme set forth herein are robust, stable, and accurate for all ranges of flow velocities commonly observed in IWR models.
Mathematical Model
[0021] Consider fluid flow through a coupled isothermal open-hole well, as schematically depicted in FIG. 1 . The open-hole well is composed of a vertical wellbore and a reservoir component. The wellbore has a diameter of D meters and a length of L w meters. The reservoir has a radius of r e and height of H meters, respectively, for the pay zone. The reservoir and wellbore are connected through an open-hole completion. Initially, the reservoir is assumed to have a uniform horizontal distribution of permeability, K(m 2 ), and porosity, φ. To ease the computational burden on two-dimensional (2D) or three-dimensional (3D) flow in the reservoir formation, the reservoir is modeled as a uniformly distributed multilayered zone so that the flow is axisymmetric and no cross-flow occurs between different reservoir layers resulting from negligible vertical permeability. Therefore, the open-hole completion system is modeled as a 1D flow network, in which each layer of the reservoir is connected with the wellbore at the junction points with no intra connections between the layers.
[0022] The system is initially filled with the resident Fluid 2, characterized by a density of ρ 2 (kg/m 3 ) and viscosity of μ 2 (pa·s). Fluid 1, with a viscosity μ 1 (pa·s) and density ρ 1 (kg/m 3 ), is injected through the wellhead, as in bullheading scenarios, at a velocity of u(t)(m/s) to displace the resident Fluid 2. To depict the fluid displacement, assume that an artificial marker is also initially filled with the system having a concentration c=0, and the same marker but with c=1 is also simultaneously injected into the system through the wellhead along with the Fluid 1 injection. The marker, as a variable c, indicates the local volume concentration of the injected fluid. The two fluids are miscible, subject to a constant diffusion coefficient, D m (m 2 /s). The compressibility effects are taken into consideration in the classical the thermodynamic fashion as it is explicitly given later by eqs. (11) and (12) with two constant compressibility values a 1 (Pa −1 ), and a 2 (Pa −1 ) for fluid 1 and fluid 2 in the reservoir, respectively.
[0023] The flow in the wellbore is described by NS equations, while it is governed by Darcy's law equations in a multilayered reservoir. The concentration field c is governed by a modified convection-diffusion equation for both the wellbore and reservoir (Wu et al. 2013), and the variation of density and viscosity with the injected fluid concentration are specified. All of these equations, along with connection conditions and boundary and initial conditions, are specified hereafter for the fluid flow and the concentration evolution in three geometric domains: wellbore, reservoir, and fluid junction zones within an open-hole completion system.
The Wellbore Domain
[0024] The fluid and marker dynamics in the wellbore are governed by the following cross-sectionally averaged mass and momentum conservation and convection-diffusion equations, respectively, so that for the 1D Cartesian coordinate system, they are as follows:
[0000]
∂
ρ
∂
t
+
∂
∂
x
(
ρ
u
)
=
0
(
1
)
∂
(
ρ
u
)
∂
t
+
∂
(
ρ
u
2
)
∂
x
+
∂
p
∂
x
+
f
f
ρ
u
2
π
D
=
∂
∂
x
(
μ
∂
u
∂
x
)
+
ρ
g
cos
θ
(
2
)
∂
c
∂
t
+
∂
∂
x
(
λ
uc
)
=
∂
∂
x
(
D
e
∂
c
∂
x
)
(
3
)
[0025] where Eq. 1 is the fluid mass continuity and Eq. 2 is the momentum conservation equation, and where the density ρ and viscosity μ are modeled by means of linear functions of concentration c as follows:
[0000] ρ=(ρ 1 −ρ 2 ) c+ρ 2 (4)
[0000] μ=(μ 1 −μ 2 ) c+μ 2 (5)
[0026] The friction force f f in the momentum Eq. 2 is modeled as
[0000]
f
f
=
{
64
Re
Re
≤
2300
0.079
Re
-
0.25
Re
>
2300
[0027] where the Reynolds number is defined as
[0000]
Re
=
ρ
UD
μ
[0000] and U is chosen as the injected fluid average velocity at the wellhead. The retarding convective factor λ and effective diffusive coefficient D e in the modified convection-diffusion Eq. 3 are modeled as the following:
[0000]
λ
=
1
-
(
λ
d
+
λ
μ
μ
2
-
μ
1
μ
2
+
μ
1
+
λ
ρ
ρ
1
-
ρ
2
ρ
2
+
ρ
1
)
f
f
2
D
e
=
D
m
+
(
D
d
+
D
μ
μ
2
-
μ
1
μ
2
+
μ
1
+
D
ρ
ρ
1
-
ρ
2
ρ
2
+
ρ
1
)
UD
[0028] The retarding convective factor λ depends on four contributions—pure convection, the retarding dispersion λ d , the viscosity difference λ μ , and the density difference λ p . Similarly, the effective diffusive coefficient D e also depends on four contributors, namely the molecular diffusion (D m ), the dispersion (D d ), the viscosity difference (D μ ), and the density difference (D ρ ). These seven parameters must be evaluated from appropriate experiments or by means of average operations over the 2D or 3D computational simulations on the same simulation scenarios; see, for example, Wu et al. (2013).
The Reservoir Domain
[0029] The governing equations for the fluids and the marker in the reservoir are similar as for the wellbore but are formulated in a radial coordinate system for the flow in a porous medium, and the momentum equation is replaced by Darcy's equation for the porous media.
[0000]
∂
(
φ
ρ
)
∂
t
+
∂
(
r
ρ
u
)
∂
r
=
0
(
6
)
u
=
-
K
μ
∂
p
∂
r
(
7
)
∂
(
φ
c
)
∂
t
+
1
r
∂
∂
r
(
r
λ
uc
)
=
1
r
∂
∂
r
(
r
(
D
e
+
D
d
ρ
)
φ
∂
c
∂
r
)
(
8
)
[0030] The fluid density ρ and viscosityμ, as well as both the retarding convective factor λ and effective diffusive coefficient D e , are modeled similarly to their formulation in the wellbore domain. The additional D dp term is the kinematic dispersion in a porous reservoir, and its current model is D dp =a L |u|, where a L is the longitudinal dispersivity.
[0031] The density and viscosity mixture of two fluids are modelled as the same as those in Eq. (4), and Eq. (5), for convenience, they are also repeated here for the reservoir domain.
[0000] ρ=(ρ 1 −ρ 2 ) c+ρ 2 (9)
[0000] μ=(μ 1 −μ 2 ) c+μ 2 (10)
[0032] In addition, two fluids in the reservoir satisfies the equation of state
[0000] dρ 1 =a 1 ρ 1 dp (11)
[0000] dρ 2 =a 2 ρ 2 dp (12)
The Connection Conditions
[0033] The reservoir formation is decomposed into uniform N layers, with the layer's height as h(=H/N). To properly connect the flow and the marker in the wellbore and reservoir, connection equations are required at all N connection points. These connection equations include the mass conservation, the marker conservation, pressure continuity, density continuity, viscosity continuity, and Darcy's law to model the velocity u r at all connection points, except the last one. Specifically, at any connection point i(i≠N), the equations are as follows:
[0000]
ρ
in
u
w
,
in
-
ρ
out
u
w
,
out
=
2
h
R
w
ρ
r
u
r
(
13
)
c
in
u
w
,
in
-
c
out
u
w
,
out
=
2
h
R
w
c
r
u
r
(
14
)
p
w
=
p
r
(
15
)
μ
w
=
μ
r
(
16
)
ρ
w
=
ρ
r
(
17
)
u
r
=
-
K
μ
∂
p
∂
r
(
18
)
[0034] At the last connection point, because all of the remaining fluid and markers leave the domain, the connection equations include mass conservation, the marker conservation, density continuity, viscosity continuity, and Darcy's law to model the pressure as the following:
[0000]
u
w
=
2
h
R
w
u
r
(
19
)
c
w
=
c
r
(
20
)
μ
w
=
μ
r
(
21
)
ρ
w
=
ρ
r
(
22
)
∂
p
∂
r
=
-
μ
ρ
u
r
(
23
)
[0035] where any variable with subscripts r and w represent the variable at reservoir and wellbore, respectively, and any variable (i.e., the velocity and concentration of the marker) with subscripts in and out represent the variable flows into and out of the intersection, respectively.
[0036] Equation 15 matches the pressure in the wellbore and reservoir at the junctions, except at the last junction point. At that point, the mass and all scalars, including the concentration, density, and viscosity flow, are matched, yet pressure is obtained from Darcy's law using Eq. 23. The pressure grid in the wellbore is connected to the reservoir pressure grid at the junctions, as can been observed in FIG. 2 , while the velocity grid at the last junction is connected to the pressure grid, ensuring continuity of pressure and velocity, respectively, in the respective junctions. The flow loss at the junction zones in the 1D simulation, for an infinitesimal area, results in a mathematical singularity, which is not a real physical singularity. It was found that using double nodes at the junction zones relieves the mathematical singularity; yet, the concentration, density, and viscosity are collocated with velocity. This is a novel method for implicitly integrating the wellbore and reservoir with the mass, momentum, concentration flux, density, and viscosity conserved. Therefore, this tightly coupled methodology results in robust simulations of the miscible fluid displacement in hybrid wellbore-reservoir systems.
The Boundary and Initial Conditions
[0037] Appropriate boundary conditions and initial conditions are required to close the system of equations. The following conditions are used:
[0000]
u
|
x
=
0
=
u
inlet
(
24
)
c
|
x
=
0
=
1.0
(
25
)
ρ
|
x
=
0
=
ρ
1
(
26
)
μ
|
x
=
0
=
μ
1
(
27
)
∂
(
φ
c
)
∂
t
+
1
r
∂
(
λ
r
ruc
)
∂
r
|
r
=
r
e
=
0
(
28
)
p
|
r
=
r
e
=
p
e
(
29
)
u
x
=
L
=
0
,
c
x
=
L
=
0
(
30
)
[0038] along with initial conditions of u| t=0 =0, c| t=0 =0, ρ| t=0 =ρ 2 , and μ| t=0 =μ 2 .
The Numerical Algorithm and Results
[0039] Numerical Algorithm.
[0040] The coupled NS/Darcy equation and fluid displacement convection-diffusion equation system (Eqs. 1 through 12) are numerically marched in time using a first-order implicit method and are solved in space using either a spatially SOUR scheme or first-order upwind scheme for the convective terms and a second-order central scheme for second spatial derivatives. The five variables are arranged as shown in FIG. 2 , with the velocity, concentration, density, and viscosity collocated, while the pressure is staggered at the respective discretization nodes. The connection equations (Eqs. 13 through 23) are implemented at the connection points to close the system implicitly.
[0041] SOUR Scheme.
[0042] The main goal of this scheme is to generate a highly accurate expression for the odd-order derivative terms in the equations, while prevailing the overall diagonal dominance of the discrete equation and maintaining its well-performed, fast, and stable methodology. The SOU scheme is second-order accurate but cannot be used near the boundaries because of its wide stencil. Hence, the SOU scheme must be modified or reverted back to a first-order scheme for application near the boundary nodes. The main advantage of the SOUR scheme is using a unified higher-order scheme throughout the domain without switching or modifying the scheme near the boundaries to be higher-order accurate, such as the standard SOU scheme. The SOUR scheme does this by using the underlying governing equation to express the higher-order derivatives. The SOUR scheme is demonstrated by using the simplified convection-diffusion equation:
[0000]
∂
C
∂
t
+
∂
(
uC
)
∂
x
-
D
∂
2
C
∂
x
2
=
f
[0043] Discretizing the equation using first-order upwind gives
[0000]
C
i
n
+
1
-
C
i
n
Δ
t
+
(
uC
)
i
-
(
uC
)
i
-
1
Δ
x
-
D
C
i
-
1
2
C
i
+
C
i
+
1
Δ
x
2
=
f
i
[0044] To make it second-order accurate, higher-order terms are included:
[0000]
C
i
n
+
1
-
C
i
n
Δ
t
+
(
uC
)
i
-
(
uC
)
i
-
1
Δ
x
+
1
2.
Δ
x
(
uC
)
xxi
-
D
C
i
-
1
2
C
i
+
C
i
+
1
Δ
x
2
=
f
i
[0045] Using the governing equation for (uC) xxi gives
[0000] ( uC ) xxi =f ix +DC xxxi −C xit
[0046] Substituting in the discretized equation:
[0000]
C
i
n
+
1
-
C
i
n
Δ
t
+
(
uC
)
i
-
(
uC
)
i
-
1
Δ
x
+
1
2.
Δ
x
(
f
ix
+
D
C
xxxi
-
C
xit
)
-
D
C
i
-
1
2
C
i
+
C
i
+
1
Δ
x
2
=
f
i
C
xxxi
=
1
Δ
x
3
{
(
C
i
+
2
-
3
C
i
+
1
+
3
C
i
-
C
i
-
1
)
-
5
Δ
x
8
C
xxxxi
or
Where
C
xxxi
=
1
Δ
x
3
{
(
C
i
+
1
-
3
C
i
+
3
C
i
-
1
-
C
i
-
2
)
+
5
Δ
x
8
C
xxxxi
C
ixt
=
-
1
Δ
x
{
C
i
n
+
1
-
C
i
n
Δ
t
-
C
i
-
1
n
+
1
-
C
i
-
1
n
Δ
t
}
[0047] As can be observed, the SOUR scheme uses the underlying governing equation to formulate a SOU scheme. This approach can be extended to other equations for stability, accuracy, and computational speed. This formulation can be used for very a high Reynolds number.
[0048] Validation.
[0049] MMS is a technique used for the current code validation. MMS uses a prescribed function of the solution of the variable to derive an expression for the source term from the governing equation. This source term is added to the linear system to solve for the numerical solution, which can then be compared to the prescribed solution for accuracy and fixing bugs in the code. MMS is a very powerful method for very large scientific codes to validate and verify purposes. This is the first step before experimental or field validation of the actual physics of the problem.
Example 1
Linear Test Function
[0050] The following test functions were used in the wellbore: u=xt, p=xt, and c=xt, and u=rt, p=rt, and c=rt was the test functions used in the reservoir. Also, only for the MMS, the following values were used: μ 1 =2.0×10 −3 (pa·s), ρ 1 =2.0×10 3 (kg/m 3 ), and μ 2 =1.0×10 − (pa·s), ρ 2 =1.0×10 3 (kg/m 3 ), as well as λ=1, D e =D 0 =10 −6 (m 2 /s). The computational domain was defined by the wellbore length L w =1.0(m). The wellbore diameter was defined by D w =0.1(m), the reservoir radius by r e =1.0(m), the height by H=1.0(m), the permeability by K=1.0×10 −10 m 2 , and porosity 0.2. The two junctions were located at x=1.4 and x=1.7. The Reynolds number was 1.0×10 5 . FIG. 3 depicts the results for a grid size of 0.1 m for both the wellbore and reservoir, and a time step of 0.01 seconds. The result shows that the code resolves precisely the linear behavior, even for a larger grid size, with an absolute error of 1.0×10 −16 .
Example 2
Oscillatory Test Function
[0051] The following test functions were used: u=xt, p=t cos(πx), and c=xt in the wellbore and u=rt, p=t cos(πr), and c=rt in the reservoir with μ 1 =1.2×10 −3 (pa·s), ρ 1 =1.2×10 3 (kg/m 3 ), and μ 2 =1.0×10 −3 (pa·s), ρ 2 =1.0×10 3 (kg/m 3 ), as well as λ=1, D e =D 0 =10 −6 (m 2 /s). The computation domain was defined by the wellbore length, the wellbore diameter by D w =0.1(m), the reservoir radius by r e =1.0(m), and the height by H1.0(m). The Reynolds number was 100, the porous media permeability K=1.0×10 −6 m 2 , and the porosity 0.2. The two connection points were located at x=1.4 and x=1.7. The grid spacing was 0.01 for both the wellbore and reservoir, and the time step was 0.01 seconds. FIG. 4 depicts the comparisons. The code captures the pressure oscillatory behavior very well, and with the error for velocity and concentration is bounded within 1.0e-5, which is consistent with the second-order spatial accuracy. The maximum absolute pressure error of 1.0e-4 is consistent with the first-order accuracy in time. The larger error compared to Test Case 1 is a result of nonlinearity and the oscillatory nature of the test functions and occurs at the junctions, where velocity and concentration are actually approximated in the first-order manner.
[0052] FIG. 4 illustrates a comparison of MMS for test functions ofu=xt, p=t cos(ρx), and c=xt in the wellbore and u=rt, p=t cos(ρr), and c=rt in the reservoir at time t=1.49.
Example 3
Compressibility Effects
[0053] To examine the compressibility effect on the fluid mixture in reservoir, the computation domain the same as in Example 2 was set up, namely and oscillatory test function. The two fluids, fluid 1 and fluid 2 were assumed to have the same constant compressibility in the reservoir with the value as a 1 =a 2 =7.3×10 −10 (Pa −1 ). FIG. 5 shows the logarithmic value of fluid density difference between the fluid with compressibility and incompressible fluid in the reservoir. This test case shows the numerical procedure is well capable of taking into account fluid compressibility in the reservoir.
[0054] A case study of an open-hole drilling system consisting of a vertical wellbore and a horizontal reservoir is also helpful in understanding the present disclosure. The wellbore was assumed to have a diameter of D=0.1m and a length of L w =1000.0 m. The reservoir formation had a height of pay zone of 500.0 m, an effective outer radius ofr e =100.0 m, with the porous permeability of K=1.0×10 −6 m 2 and porosity of 0.2. And the reservoir formation was assumed to have ten uniform layers. The system was assumed to be initially filled with fluid 2, which is the case when the reservoir is filled just with water, e.g., with μ 2 =1.0×10 − (pa·s), ρ 2 =1.0×10 −3 (kg/m 3 ). Fluid 1 with μ 1 =1.2×10 −3 (pa·s), ρ 1 =1.2×10 3 (kg/m 3 ) was assumed to be injected with a velocity u inlet =5.0 m/s. Two fluids are assumed to be incompressible in the reservoir. And the retarding convective factor λ and the effective diffusion coefficient D e take forms as given by:
[0000]
λ
=
1
-
(
λ
d
+
λ
μ
μ
2
-
μ
1
μ
2
+
μ
1
+
λ
ρ
ρ
1
-
ρ
2
ρ
2
+
ρ
1
)
f
f
2
D
e
=
D
m
+
(
D
d
+
D
μ
μ
2
-
μ
1
μ
2
+
μ
1
+
D
ρ
ρ
1
-
ρ
2
ρ
2
+
ρ
1
)
UD
with
,
λ
d
=
0.184
+
1.284
tanh
(
0.0038
Pe
)
λ
μ
=
0.32
(
1
-
μ
2
μ
2
+
μ
1
)
λ
ρ
=
1
20
(
1
-
ρ
1
ρ
2
+
ρ
1
)
D
m
≡
1.0
×
10
-
6
(
m
2
/
s
)
D
d
≡
Pe
8
×
192
D
μ
≡
Sc
8
×
192
(
1
-
μ
2
μ
2
+
μ
1
)
D
ρ
≡
Re
32
×
192
(
1
-
ρ
1
ρ
2
+
ρ
1
)
[0055] Here, Re is the Reynolds number, Pe is the Peclet number, and Sc is the Schmidt number, which are defined as follows:
[0000]
Re
=
ρ
1
+
ρ
2
μ
1
+
μ
2
UD
;
Pe
=
UW
D
m
;
Sc
=
μ
1
+
μ
2
(
ρ
1
+
ρ
2
)
D
m
.
[0056] And the friction factor
[0000]
f
f
=
{
64
Re
Re
≤
2300
0.079
Re
-
0.25
Re
>
2300
,
U
=
u
inlet
,
and
α
L
=
5.0
m
/
s
[0057] with a grid size of 1.0 m for both the wellbore and reservoir and a time step of 0.1 seconds. Simulation results are shown in FIGS. 6 through 10 .
[0058] The concentration profiles in FIG. 6 show the fluid fronts and the fluid mixing zone sizes along the wellbore and the reservoir layers. In the wellbore, the concentration is 1.0, which indicates that it is filled with Fluid 1. In the reservoir, the concentration varies between 1 to 0, indicating mixing and diffusion in the reservoir. The pressure in FIG. 7 decreases but jumps at the wellbore-reservoir interface along the wellbore because of flow loss. The discontinuity of the pressure along the wellbore results from the velocity discontinuity, as shown in FIG. 8 . In the case of inviscid flow, the Bernoulli equation shows that flow loss results in pressure spikes. Moreover, the velocity at the last connection in the wellbore spikes locally because it is modeled by Darcy's law, and pressure is continuous at this last connection point. In addition, the pressure and velocity distributions along the reservoir are radial because of inherent radial flow assumptions. Viscosity profiles in FIG. 9 show the linear relationship between viscosity and the concentration; therefore, FIGS. 9 and 6 are qualitatively similar. Density profiles, which are not plotted, have profiles similar to the concentrations profiles because the linear relationship between density and concentration is used in the model.
[0059] FIG. 10 shows that contour plots of velocity, pressure, and concentration for two reservoir layers during injection at a Reynolds number of 10,000. The solution time step is 0.01 seconds, and the simulation time is 2.49 seconds. Most of the fluid flows through the second layer, as shown in FIG. 9 a , because the permeability of the first layer is smaller compared to the second layer. The solution is stable at these high Reynolds numbers typically found in wellbore flow. These results indicate that the numerical scheme developed for this model is robust and results in very stable solutions for long-period simulations.
[0060] The present disclosure presents a new physics and numerical methodology, discretization, and model to simulate the miscible fluid displacement process in any completion system. The methodology includes coupling mechanisms for scalar, velocity, and pressure dynamics at the junction points, numerical simulation approaches to solve different systems of partial differential equations in each domain, and geometrical modeling of open-hole completion systems. This study simulated the miscible fluid displacement process in an open-hole completion system. The solution obtained from numerical simulations is fast, robust, feasible, efficient, and easy to use. Prediction of miscible fluid displacement dynamics in a complex wellbore-reservoir network is a challenge but can be executed robustly with the new methodology developed here.
[0061] The model and numerical algorithm are applicable to multistage and multi-fluid transport in hybrid wellbore-reservoir systems for any well completion, such as perforation or slotted liner. Therefore, it is expected that the model can have a significant impact in the simulation of well production enhancement processes through the proposed coupling mechanisms of velocity, pressure, and marker concentration across the wellbore-reservoir interface for typical Reynolds numbers observed in the field.
[0062] Although the present disclosure 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 disclosure as defined by the following claims.
|
Computer-implemented methods for higher-order simulation, design and implementation of multi-phase, multi-fluid flows are disclosed. In one embodiment, a computer-implemented method is provided for a higher-order simulation, design and implementation of a strategy for injecting a plurality of stimulation fluids into a subterranean formation. In another embodiment, a computer-implemented method for higher-order simulation and enhancement of the flow of production fluids from a subterranean formation is disclosed. In a third embodiment, a computer-implemented higher-order simulation of the behavior of a plurality of fluids at an intersection of at least two geometrically discrete regions is disclosed.
| 6
|
BACKGROUND OF THE INVENTION
This invention relates to thermal indicators used on smoking articles. More particularly, this invention relates to thermal indicators embodied as waxes or other compounds which melt away to reveal colored substrates, or use microencapsulated chemicals, to indicate a predetermined temperature within the smoking article.
There are non-combustion smoking articles currently on the market that provide an alternative to conventional tobacco-burning smoking articles. Non-combustion smoking articles include smoking articles heated by electrical or chemical means, or by burning some type of heat source other than the tobacco itself. The tobacco or flavor source is heated, but is not burned. If the heat source is contained within the non-combustion smoking article, it provides no visual indication, such as a burning end, of the temperature gradient along the article. A smoker is unable to determine which portion of the smoking article is hot.
A person smoking a non-combustion smoking article must be informed that the device has begun to work. The smoker also needs information about the on-going operation of the device, for example, whether the heat source is still operating. Finally, the smoker must know when to stop puffing because the flavor or heat source is expended. Unless the smoker knows this, the smoker may try to use the device longer than is intended by the manufacturer, possibly resulting in customer dissatisfaction.
The thermal indicators used on smoking articles must not affect the flavor or safety of the smoking articles. The indicator materials must be non-toxic both prior to and after heating.
In view of the foregoing, it is an object of this invention to provide non-toxic thermal indicators for use on non-combustion smoking articles.
It is another object of this invention to provide a method for showing the internal thermal status of a non-combustion smoking article along its length.
SUMMARY OF THE INVENTION
These and other objects of the invention are accomplished in accordance with the principles of the invention by providing thermal indicators which physically change at a predetermined temperature to cause a visible color change. The thermal indicator means of the present invention may be one of two types. In the preferred embodiment, the thermal indicator may include a colored substrate applied to the surface of the smoking article to be monitored. This substrate is covered by an opaque, low melting point wax or other similar compound. In this embodiment, the wax coating melts away to reveal the colored substrate beneath. In an equally preferred embodiment, the thermal indicator may include microencapsuated chemicals which cause a color change by inking or dyeing the surface of the smoking article. These chemicals are released when the heat from the article melts the encapsulating material.
The thermal indicators may be applied to a smoking article in a variety of patterns using conventional printing techniques. The indicators are printed along the longitudinal length of the smoking article. As the internal temperature gradient of the smoking article moves down the length of the article, the indicators gradually reveal a color indication in response to the increased heat.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a non-combustion smoking article with an illustrative imprint of thermal indicators in accordance with the principles of this invention.
FIG. 2 is the smoking article of FIG. 1 showing two indicators whose surface material has melted away, in response to the heating of the smoking article, revealing a colored substrate.
FIG. 3 is the smoking article of FIG. 1 showing an illustrative marking used to indicate when the smoking article is finished.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Thermal indicators prepared in accordance with this invention are comprised of compounds which physically change to either reveal a colored substrate or create a color change as an indication of temperature change. The indicators are applied directly to the surface whose temperature is to be monitored.
In the preferred embodiment of the invention, low melting point waxes, gums (e.g., gum arabic), pectins, or fatty acid esters (e.g., bee wax) are applied to a colored substrate. The coating material is initially opaque, and remains as such until the surface whose temperature is being monitored reaches a predetermined temperature. At or near the predetermined temperature, the coating wicks and becomes clear. The coating thins and is absorbed into the surface (i.e., into the paper cigarette wrapper). The substrate, previously hidden beneath the opaque coating, becomes visible as an indication of temperature change.
The preferred coating materials include hydrocarbon waxes in the hydrocarbon range of C16 to C30. Compounds such as polyvinyl-1 alcohol or polyvinyl acetate, or long chain fatty acids, such as stearic acid, may be added to the coating materials as hardening agents. The coating materials may be selected and combined such that the coating will melt to reveal a color indication when subjected to a predetermined temperature within the range of 40 degrees to 220 degrees Centigrade.
The substrate may be printed in a wide variety of colors and may be printed in a variety of patterns or letters. More than one color ink may be used on a single smoking article. The thermal indicator's substrate may be selected to enhance the appearance of the smoking article to which it is applied. The substrate used for cigarettes may comprise conventional print ink, or any other non-toxic colorant, applied directly to the cigarette wrapper. The preferred coloring agent of the ink is carbon.
Referring to FIG. 1, as the smoker draws on the proximal end of smoking article 10, air is drawn though distal end 14, and past the internal heat source of the smoking article, causing the air to become heated. The heated air and flavored aerosol (which is released from the flavor source disposed within smoking article 10) are drawn down the length of the smoking article, through the filter 12, and into the smoker's mouth. Often, non-combustion smoking articles (to which the thermal indicators of this invention may be applied) are lined with foil. The foil conducts heat, gradually, back toward filter 12. As smoking progresses, an internal temperature gradient is created within smoking article 10. The smoking article is hottest at distal end 14 where the device is lit or otherwise initially heated, and cooler toward filter 12. The heated aerosol, heat-conducting foil, and possibly the heat source itself (e.g., a carbon rod burning toward filter 12) cause the temperature to increase down the length of article 10 as smoking continues. It is this temperature gradient which causes certain indicators to heat sufficiently to cause a color change, while other thermal indicators, located on cooler portions of the smoking article, remain invisible (i.e., they have not been sufficiently heated to cause the opaque coatings or encapsulating materials to melt).
FIG. 1 shows a smoking article 10 imprinted with thermal indicators collectively indicated by reference numeral 16. In an illustrative embodiment of this invention, the thermal indicators are printed in a series of small dots. Indicators 16 are printed at distal end 14 and down the length of smoking article 10. In alternative embodiments of the invention, indicators 16 may be printed or sprayed onto the outer surface of smoking article 10 as lines or letters, or in any of a variety of patterns.
FIG. 2 shows the smoking article of FIG. 1 after the device has begun to operate. Before article 10 is smoked, all of the indicators 16 are opaque (as shown in FIG. 1). At the beginning of smoking, distal end 14 is the first portion to experience a temperature rise. When this happens, the surface layer of the indicator 18 closest to distal end 14 begins to melt, revealing the colored substrate beneath. As smoking progresses, the surface of indicator 20 also melts, revealing the colored substrate. Thermal indicator 22 will be the next to change, as the internal temperature gradient of the smoking article progressively moves toward the proximal end. In this way, the smoker is alerted that smoking article 10 is still hot and is still operating.
FIG. 3 shows the smoking article of FIG. 1, having means for indicating when smoking article 10 is finished. This embodiment is particularly suited for smoking articles comprising a heat source which extends longitudinally down the length of the article and heats gradually from distal end 14 toward filter 12 (such as a burning carbon rod).
In FIG. 3, a marking 24 is printed on the surface of article 10 of FIG. 1. Marking 24 is preferably printed in ink, but may also be printed with the same materials as indicators 16. Marking 24 is disposed before the thermal indicator closest to filter 12, i.e., between indicators 26 and 28. Thermal indicator 28, located beyond marking 24, changes color when the area surrounding the proximal end of article 10 becomes hot. This may occur, for example, when a heat source, such as a burning rod of carbon, burns to the end of article 10. Indicator 28 alerts the smoker that smoking article 10 is finished and should be discarded.
In an alternative embodiment of the invention, the thermal indicators comprise microencapsulated chemicals. The microencapsulated chemicals include inks and dyes, color producing materials, solvents for the inks, water, or alcohols. Precursors to inks or dyes (i.e., selected components of multiple-component inks or dyes) may also be microencapsulated. When the monitored surface reaches a predetermined temperature, the encapsulating materials melt and release the encased chemicals, resulting in the inking or dyeing of the smoking article. In this embodiment, a solution comprising microencapsulated chemicals is printed directly on the smoking article. There is no colored substrate beneath the microencapsulated chemical solution.
Thermal indicators in accordance with this invention may be applied to smoking articles using standard methods of printing on cigarette wrappers. Preferably, the indicators are applied to the smoking article by means of a print wheel. This method is suitable for applying indicators comprising microencapsulated chemicals.
Where the thermal indicator includes a colored substrate beneath a waxy coating, a more complicated printing procedure is required. The substrate, preferably printed with conventional print ink, is first applied to the cigarette wrapper by a first print wheel. The opaque wax coating is superimposed upon the substrate by a second print wheel. In an alternative embodiment, the substrate of the indicator is imprinted on the cigarette wrapper by means of spray jets, in lieu of using the first print wheel. The opaque wax coating is again superimposed upon the substrate by a print wheel.
In embodiments utilizing a colored substrate and opaque wax coating, the wax may be applied to the smoking article either hot or cold. The wax is preferably applied when cod. Solvents are added to the wax to obtain the desired wax viscosity for proper bonding of the cold wax to the substrate and cigarette paper. Food-grade vegetable oil is a solvent suitable for this application.
It will be understood that the foregoing is merely illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art of the invention. For example, the indicator material may be printed in a continuous line down the length of smoking article 10, in pace of the pattern of dots, in the embodiment of FIG. 1.
|
Thermal indicators for non-combustion smoking articles which physically change when heated to provide visual indications of temperature changes are disclosed. The indicators comprise waxes or other compounds which melt away to reveal colored substrates, or comprise microencapsulated chemicals which are released when heated to cause inking or dyeing. The thermal indicators are printed in variety of patterns along the length of the smoking articles to show temperature changes and to indicate whether the smoking article is finished and should be discarded.
| 0
|
FIELD OF THE ART
[0001] The present invention is directed, in general, to wireless communications, and more particularly to a method for coordinating Access Points for backhaul aggregation in a telecommunications network and a device for backhaul aggregation therefore providing a high-level distributed coordination/planning scheme for AP-based backhaul aggregation solutions.
BACKGROUND OF THE INVENTION
[0002] Wireless Local Area Network (WLAN) technology is being globally adopted in anyone's house as a must-have connectivity medium for our daily life. Driven by the market needs, subsequent WLAN protocol standards have be defined for medium access control and physical layer. IEEE released the original 802.11 protocol, RFC5416 in 1997 and up to six more versions have been published until then aimed to increase both the capacity and the signal coverage distance. In 2014, 802.11ad is published to provide a theoretical maximum data throughput of up to 7.0 Gbps.
[0003] Opposite of the fast WLAN technology development, consumer broadband Internet access technologies is experimenting a notable slowing down in new breakthroughs. The new ADSL2++ (52.0 Mbps downstream rate) is still in development after the last ADSL2+, RFC4706, version release in 2008. Although the fiber technology provides an alternative, the higher infrastructure deployment cost makes it less attractive for ISPs.
[0004] Motivated by the current trend in technology development and the economic incentives, new communication architecture designs have been proposed to combine existing WLAN and broadband technologies. The new combined solutions provide higher performance without requiring any new infrastructure deployments. For instance, Domenico Giustiniano et al “Fair WLAN Backhaul Aggregation”[1] proposed a client-based solution to aggregate the WLAN backhaul capacity with a virtualized WIFI antenna that is able to connect simultaneously to multiple APs. Such virtualized antenna enables WIFI devices (e.g.: laptop or phones) to connect with multiples APs at same time. Nevertheless, such antenna virtualization requires chipset support and specific driver development per device, which involves high and prohibitive costs in a massive adoption. [1] “Fair WLAN Backhaul Aggregation”, Domenico Giustiniano, Eduard Goma, Alberto Lopez Toledo, P. Rodriguez, ACM/MOBICOM 10, Sep. 2010.
[0005] Patent application WO 2013/011088 proposes to aggregate backhaul capacities in an Access Point (AP) enabling one single-radio AP to behave both as a AP for home users and as a client of other neighboring APs that could be in different WALN channels. In order to connect to the neighboring APs, it was proposed to use Network Allocation Vector (NAV) to silence all clients, so have time to switch to other APs for data exchange.
[0006] In one hand, AP-based solutions have the advantage of providing backhaul aggregation without any modification in clients. In other hand, it involves remarkable coordination and planning challenges. For instance, each AP has to decide which neighbor APs should aggregate with. Allow all AP to collaborate with all neighboring APs is not a practical solution because it can degrade the performance of all involved WLAN networks. For instance, in WO 2013/011088 APs can switch off all neighboring WLANs by control frames. On more practical solution may be allocating all APs in the same channel, so avoid unnecessary switching offs. Such a solution, however, limits the total capacity of different neighboring WLANs and suffers WIFI well known problem in performance degradation because higher number of devices or long-distanced WIFI clients.
[0007] Patent EP-B1-2263398 proposes a routing scheme for mesh-network where multiples relay nodes are interconnected to access the Internet. The proposed scheme computes the best routing and bandwidth allocation according the collected network information. Similarly, patent U.S. Pat. No. B2-8,442,003 proposes to use information from different access points and backhaul throughput to select the best access point in a mesh-network. On contrary, present invention is focused on WLAN backhaul aggregation platforms and there are not relay nodes. Each of the nodes in the present invention has independent backhaul connection and the goal is optimize the overall utilization of all backhaul links.
[0008] U.S. Pat. No. B2-6,772,199 describes a QoS management framework where QoS information is broadcasted by different nodes with management frames in a mesh-network. Although QoS management is important for the well-functioning of the proposed aggregation scheme, present invention does not provide any QoS management. Thus U.S. Pat. No. B2-6,772,199 could be totally complementary to present invention.
[0009] In the context of mesh-network, there are also proposals related to transmission control, such as patent application WO-A2-2007/103891 where frameworks define when and how devices access the communication medium. The same problem is also inherent in present invention proposal and other WIFI-based systems. WO-A2-2007/103891 does also apply to present invention proposal.
SUMMARY OF THE INVENTION
[0010] According to a first aspect there is provided a method for coordinating Access Points for backhaul aggregation in a telecommunications network, comprising as commonly in the field: a) monitoring, by an access point in a telecommunication network, network data traffic information from at least one user computing device connected thereto; and b) detecting, by said access point, an adjacent access point in said telecommunication network available for performing backhaul aggregation.
[0011] On contrary of the known proposal, the method of the first aspect comprises: performing said steps a) and b) by a plurality of access points forming a cluster of access points; obtaining, by all the access points of the cluster, a status profile by using said network data traffic information monitored in step a) and by using information regarding said detected adjacent access points found in step b); reporting, by all the access points in said cluster, an own identifier to a remote server; obtaining, by said remote server, by means of said reporting, a record including the corresponding identifier of each access point; building, by all the access points in said cluster, by means of said obtaining, a list of access points available for performing backhaul aggregation; establishing connections between available access points forming sub-clusters of access points; and acting one of said access points as a cluster coordinator coordinating the formed sub-clusters of access points for a backhaul aggregation.
[0012] Each of said sub-clusters has a sub-cluster coordinator, which has been designated by means of a voting process performed by all the access points forming part of said sub-cluster.
[0013] The cluster coordinator on other hand is the access point most voted of said sub-cluster coordinators.
[0014] In addition, a sub-cluster reserve coordinator is also designated in the voting process. The sub-cluster reserve coordinator generally will be the second most voted access point in the voting process.
[0015] In an embodiment, the cluster coordinator comprises performing as part of the coordinating step: selecting from said sub-clusters at least one sub-cluster in charge of performing backhaul aggregation; and deciding between said selected sub-cluster the wireless channel through which performing said backhaul aggregation. Preferably, the sub-cluster is selected considering the network data traffic information and/or signal strength of the access points.
[0016] It could be de case that an access point belongs or forms part of different sub-cluster of access points. In this case, the access point has the option to decide in which sub-cluster of said different sub-clusters residing. Preferably, the access point decides to stay in the most loaded sub-cluster.
[0017] The remote server periodically checks the obtained record and further removes from the latter the access points that haven't been report the own identifier in a certain period of time.
[0018] The status profile obtained by each of the access points, in addition to the monitored network data traffic information and the information regarding said detected adjacent access points would preferably further include: status of the connected user computing device; estimation about network data traffic requirements; channel occupancy rate and noise level and network signal strength of the detected adjacent access points.
[0019] According to a second aspect there is provided a device for backhaul aggregation comprising as commonly known: means for monitoring network data traffic information from at least one user computing device connected thereto; means for detecting at least one access point available for performing backhaul aggregation; and means for establishing a control channel with at least said detected access point. On contrary of the known proposals, the device further comprises: means for obtaining a status profile; means for reporting an own identifier to a remote server; and means for at least acting as a cluster coordinator of a plurality of sub-clusters of said cluster for a backhaul aggregation.
[0020] In an embodiment, the device of the second aspect is an access point forming part of a same physical entity of an associated broadband router. Alternatively, in another embodiment, said device is an access point forming part of a different physical entity of said associated broadband router.
[0021] The device of the second aspect is adapted to implement the method of the first aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The previous and other advantages and features will be more deeply understood from the following detailed description of embodiments, with reference to the attached, which must be considered in an illustrative and non-limiting manner, in which:
[0023] FIG. 1 is an illustration of the general architecture model for the proposed WLAN backhaul aggregation scheme.
[0024] FIG. 2 is an illustration of the different modules that are included in each access point according to some embodiments.
[0025] FIG. 3 is an illustration of the AP Environment Monitor module.
[0026] FIG. 4 is an illustration of the AP Discovery module.
[0027] FIG. 5 illustrates an example in which an access point is mutually visible in four different sub-clusters.
[0028] FIG. 6 illustrates the active AP sub-cluster selection process according to an embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0029] The invention is composed by a set of control modules that run in the access points that perform WLAN backhaul aggregation, and a backend system that operates in the cloud. The control modules and the backend system work in collaboration to optimize the performance of backhaul aggregation
[0030] FIG. 1 illustrates the general architecture model for the proposed WLAN backhaul aggregation scheme. The architecture model is composed by a set of access points APs, each access point AP being associated to a broadband router that provides the backhaul link. In an embodiment, the access point AP and the broadband router could be implemented as different physical entities or alternatively they could form part of a same physical entity.
[0031] Different access points APs can form an access point AP cluster or community and each community can contain multiple active access point AP sub-clusters or neighborhoods. An active access point AP neighborhood generally is composed by more than one access point AP, that share the backhaul links by sending the monitored home-users traffic to multiple links. The invention does not include any routing policy to guarantee the fairness between home-users. Proposals like [1] do apply here to solve the fairness problem.
[0032] In an embodiment, each access point AP cluster may include one or more cluster or community coordinators. The selection of coordinator is distributed and provides scalability and fault-tolerance
[0033] FIG. 2 shows the different modules or means that may be included in each access point AP. Following, each of said different modules or means are described in more detailed.
[0034] AP Environment Monitor module: Each access point AP runs a module that constantly monitors the home-user traffic or network data traffic information and scans the WIFI environment of the cluster to generate a status profile. The status profile preferably includes: the status of home user connected devices, estimation about home users' traffic requirement, the channel occupancy rate and noise level and detected additional access points APs (visible neighboring APs) and signal strength of the same.
[0035] FIG. 3 illustrates the detail design of this AP Environment Monitor module. All monitored network data traffic information is collected by AP Environment Monitor module 1 to build the AP status profile. There are three other monitors that allow generating all required information. The Backhaul Link Monitor 2 which constantly monitors the backhaul traffic and generates information regarding: Backhaul link Capacity 4 , Link Utilization 5 and Local Traffic 6 . In order to measure the link capacity, periodical prove packets are generated to well-known speed test servers. Passive measurement techniques may also be used to provide a more accurate estimation.
[0036] Link utilization is measured by counting the traffic to the broadband router and entire network traffic are divided to local home-user traffic and remote user traffic. Wifi Traffic Monitor 8 calculates the Channel Occupancy 10 in all available channels by performing periodical samplings. AP Visibility Monitor 9 generates the list of visible APs (Basic Service Set Identifier BSSIDs) with the correspondent information about signal strength.
[0037] AP Discovery module: All access points APs in the present invention has its own backhaul link and each of them has to talk with other to exchange information. In order to perform this, each access point AP establishes backhaul communication channels with other neighboring access points APs. AP Discovery module provides the mechanism to known the public IP address of each access point AP.
[0038] FIG. 4 illustrates the detail design of this AP discovery module. Each access point AP periodically connects 20 to a remote server or AP Centralized Directory 10 to report the own identifier or BSSID. The AP Centralized Directory 10 then builds a map or record 30 to store the public IP address correspondent to each BSSID. In an embodiment, all entries in said record 30 are periodically checked, so APs that haven't reported its BSSID in more than a determined period of time are removed from the record. Preferably, the value of said determined period of time is ten minutes, but it could be any other. Then, given the list of visible BSSIDs 50 , the BSSID Resolution 40 module connects to the AP Centralized Directory 10 to retrieve the correspondent public IP address. At end of the entire process, the list of all visible IPs 60 is built in each AP.
[0039] AP Neighborhood Establishment module: All pairs of two mutually visible access points APs are neighbors or what is the same they form part of the same sub-cluster. In order to know that two access points APs see each other, control channels are established between each pair of access points APs. For instance, if an AP-A doesn't see other AP-B that is trying to establish the control channel, the AP-A refuses the connection.
[0040] There are situations that an access point AP can belong to multiple possible sub-clusters or neighborhoods. FIG. 5 shows an example where nine access points APs are mutually visible in four different sub-clusters. While AP-A can only see C-B-D, AP-C can see nodes that are not visible for AP-A, for install node I. In such situation, C can choose which sub-cluster or neighborhood will belong to. Similar situation happens to AP-D that can choose four different neighborhoods.
[0041] In order to decide which AP sub-cluster belongs to, each access point AP may choose first randomly to stay to one of the sub-clusters. For other sub-clusters, access point AP will report to be “abroad”. When an access point AP is in abroad, non-access point AP will select it to forward the traffic, but all other control information will be propagated to the access point AP.
[0042] Periodically, each access point AP that could belong to multiple sub-clusters calculates the traffic in each sub-cluster and as a preferred option selects the most loaded sub-cluster to stay with. The idea is to contribute the backhaul capacity to those sub-clusters that really need them.
[0043] Neighborhood Coordinator Selection module: For each sub-cluster or neighborhood, an access point AP will be selected to be the main coordinator. The cluster or community coordinator is on charge of coordinating entire community to provide the optimal performance. In order to provide fault-tolerance, a sub-cluster reserve coordinator may also be selected.
[0044] The sub-cluster coordinator is designated by means of a voting process performed by all the access points forming part of said sub-cluster. In said voting process, each access point AP randomly votes two access points APs to be coordinators. The one access point AP that got more votes will be selected to be the main sub-cluster coordinator and the second one will be the sub-cluster reserve coordinator. On the other hand, the cluster or community coordinator is the access point most voted of said sub-cluster coordinators.
[0045] Active AP Neighborhood Selection module: One of the tasks of the cluster or community coordinator is the active sub-cluster or neighborhood selection. The cluster coordinator decides the subset of access points APs inside the cluster that actively performs backhaul aggregation. The result of this process is isolated sub-clusters of access points APs that share backhaul connections. The cluster coordinator mainly uses traffic statistics of all access points APs to avoid sub-clusters with more than one heavy user. The idea is to optimize the aggregation opportunity in each sub-cluster.
[0046] The cluster coordinator does also can decide the wireless channels that each sub-cluster has to use. The idea is to distribute the per-channel occupancy and optimized the WLAN performance.
[0047] FIG. 6 illustrates the entire process of the said active AP neighborhood selection. Based on AP status profiles 100 , which was generated for all the access points APs included in the cluster, two competitive and independent modules 200 and 300 propose different access point AP pairs candidates. Module 200 selects access points APs according to the network data traffic information (the local home-user traffic). The idea is to match pairs of access points APs with different traffic load. Module 300 , in other hand, selects pairs with strong signal strength. The idea is to optimize the Wifi throughput. The output of module 200 and 300 are a list of AP-pairs with a value between (0.0-1.0) that evaluates the goodness of each pair. Module 400 then combines both results to generate the final access point AP pair's candidates 500 . Once the access point AP pairs are selected, channel optimization module 600 establishes channels that pair of access points APs should use. The idea is to avoid signal interference between channels.
[0048] Different design aspects of the invention provide a feasible scalable solution to coordinate multiple access points APs for backhaul aggregation. The cluster or community coordination mechanism is entirely distributed and only a small piece of information is required to be stored in the AP centralized directory 1 . The invention design guarantees the scalability to a large number of access points APs. Fault-tolerance is also provides by selecting multiple coordinators inside each cluster.
[0049] The active neighboring AP selection module coordinates one AP cluster to use efficiently multiple wireless or Wifi channels, thus reduce the contention in each Wifi channel. Furthermore the mechanism optimizes the backhaul bandwidth efficiency by pairing heavy home-users with others with less traffic. The overall result is better local WLAN performance while optimizes backhaul connection utilization.
[0050] The scope of the invention is given by the appended claims and all variations and equivalents which fall within the range of the claims are intended to be embraced therein.
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In the method, a plurality of access points forming a cluster in a telecommunication network monitors network data traffic information from at least one user computing device connected thereto; obtains a status profile; reports an own identifier to a remote server; builds, by using a record including the corresponding identifier of each access point, a list of access points available for performing backhaul aggregation; and establishes connections between available access points forming sub-clusters of access points. Wherein, one of the access points acts as a cluster coordinator coordinating said formed sub-clusters of access points for a backhaul aggregation.
The device is adapted to implement the method.
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RELATED APPLICATIONS
This application claims the benefit of the Norwegian application 1999 2739 filed Jun. 4, 1999 and the international application PCT/NO00/00192 filed Jun. 2, 2000. This application is related to co-pending applications “RELEASE MECHANISM IN A MISSILE” Ser. No. 10/009,281 “TRANSLATION AND LOCKING MECHANISM IN A MISSILE” Ser. No. 10/009,283 and “PROPELLING DEVICE FOR A PROJECTILE IN A MISSILE” Ser. No. 09/980,944 all filed concurrently herewith.
BACKGROUND OF THE INVENTION FIELD OF THE INVENTION
The present invention relates to a retarding and locking means for use between two bodies where the one, first body can be activated to motion and guidance into the other, second body and after a predetermined movement of the fist body is said first body being braked, or retarded, and perform thereafter interlocking with the second body and the interlocked bodies form together a unitary or integrated body.
The invention also relates to a method for retardation of a first body having kinetic energy and subsequent interlocking of the first body to a second body by use of deformation forces.
DESCRIPTION OF THE RELATED ART
The disclosed retarding and locking means is developed in connection with a missile, but is considered usable in other, civil relations where two main bodies are to be interlocked by means of kinetic energy and by deformation of a third body, or element, which is provided between the two main bodies. This can be actual for the integration of two basically separated bodies and where it either is not desired to weld or solder the bodies together or where the joining spot is inaccessible for a welding operation.
The further description of the invention is related to use in missiles, and in particular rocket accelerated penetrators. Rocket accelerated penetrators are often kept in their storing and standby state with the main parts thereof not assembled. This means that the part having control fins, the fin cone, and the rocket motor proper is assembled to the penetrator at the moment before the missile is launched from the launcher. The penetrator, which is in form of an arrow like body having substantial mass, is lying in standby position with the pointed end thereof supported in the control fin part. During launching preparations the penetrator is translated through the control fin part and the rear end of the penetrator is interlocked to the control fin part immediately before the rocket motor is ignited. It is common practise that the rocket motor is separated from the penetrator during the flight thereof as soon as the rocket motor is burned out and has lost its propelling force.
SUMMARY OF THE INVENTION
In accordance with the invention, a retarding and locking means of the introductorily mentioned kind is provided, which is distinguished in that the first body has a radially outwards directed shoulder and the second body has a radially inwards directed shoulder which correspond with the radially outwards directed shoulder, and that a compressible element is provided between said shoulders.
As a first option, the compressible element can be lying in standby position against the radially outwards directed shoulder.
As a second option, the compressible element can be lying in standby position against the radially inwards dirt shoulder.
Conveniently, the compressible element can be in form of a deformable sleeve. The sleeve may have a slight conical configuration and have a collar in at least one end thereof.
In one embodiment, the first and second body and the compressible element, can be cylindrical in the contacting surfaces thereof.
Preferably, the inwards directed shoulder may comprise an outwards directed recess in respect of the internal surface of the body.
Preferably, the outwards directed shoulder may comprise an inwards directed recess in, respect of the external surface of the body.
Further, after the interlocking option, said recesses can preferably be axially staggered in respect of each other.
In one embodiment of the invention the said bodies are included in a missile. The first body can be a penetrator and the second body can be a tail part having control fins.
In accordance with the present invention, a method of the introductorily mentioned kind is also provided, which is distinguished in that a deformable element is provided between the first and the second body and the kinetic energy of the first body is transferred to and absorbed in the deformable element during the retardation thereof over a predetermined retardation distance, said deformable element expands radially and engages surfaces on both bodies and after terminated retardation interlocks the bodies to each other in predetermined position.
Advantageously, the deformable body can be designed such that it is deforming in an accordion like pattern and forms a series of edges that do engage with the said surfaces.
Conveniently, the deformable clement can be designed such that the formation of edges occurs in more random orientations and in directions beyond radial planes.
Other and further objects, features and advantages will appear from the following description of one for the time being preferred embodiment of the invention, which is given for the purpose of description, without thereby being limiting, and given in context with the appended drawings where:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a rocket accelerated penetrator,
FIG. 2 shows the front end of a penetrator in the storing position thereof inside a control fin part and a rocket motor,
FIG. 3 shows the same as FIG. 2, but in closer detail,
FIG. 3A shows the circumscribed detail of FIG. 3 in enlarged scale,
FIG. 4 shows the rear end of a penetrator in launching position and having the control fin part integrated to the penetrator,
FIG. 4A shows the circumscribed detail of FIG. 4 in enlarged scale,
FIGS. 5-11 show in detail and in enlarged scale sequences during the integration process between the penetrator and the control fin pat.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
We firstly refer to FIG. 1 that illustrates a missile in flight. The missile comprises a penetrator 1 , a control fin part 5 and a rocket motor 10 as main components. The penetrator 1 is an arrow like body having substantial mass, preferably of tungsten. The penetrator is omit warhead and do achieve its destructive effect owing to the kinetic energy thereof FIG. 2 shows the forward pointed end of the penetrator 1 in the way it is lying in standby position in the control fin part 5 and the rocket motor 10 during storage until launching from a launching pipe or launcher (not shown). The reference number 8 refers to one of four control fins that are located circumferentially about a centre and having equal pitch or angular distance from each other. The number of fins 8 can vary according to desire. The rocket motor 10 is releasably fixed to the control fin part 5 . The rocket motor 10 is released and does separate from the control fin part 5 during the flight of the missile.
FIG. 3 shows the front end of the penetrator 1 and the control fin part 5 in closer detail. In the circumscribed area is a sleeve 2 shown that is abutting a shoulder 6 on the internal surface of the control fin part 5 . The sleeve 2 is shown further enlarged in FIG. 3 A. The sleeve 2 can be manufactured of different materials, be of different geometric configurations and dimensions, all according to those criteria that are determined for retardation and locking. The sleeve is preferably a thin walled tubular element and can be manufactured of materials like steel, aluminium, brass, copper or to the end suitable alloys. The sleeve 2 may as an option have a collar 2 a in one end or both ends like that indicated in FIGS. 5-11. The sleeve may also, as an alternative, have a slight conical form having the tapering facing towards the shoulder 3 on the body 1 that is moving.
FIG. 4 shows the rear end of the penetrator 1 when the penetrator 1 is translated through the control fin part 5 . The rear end of the penetrator 1 has a shoulder 3 that is directed radially outwards. This shoulder 3 is designed to hit the sleeve 2 in the opposite end to the shoulder 6 . A pyrotechnic charge, or igniter charge, propels a piston 9 , which again translates the penetrator 1 until the penetrator 1 hits the sleeve 2 by the shoulder 3 thereof. Thus a deformation of the sleeve 2 occurs, which is illustrated in enlarged scale in FIG. 4A when in final position thereof. In FIG. 4A is the compression shown as a number of knife like edges that are folded together in an accordion lice pattern.
As an alternative, the sleeve 2 can initially abut against the shoulder 3 on the penetrator 1 and accompany the penetrator 1 during the translation until the sleeve 2 hits the shoulder 6 on the control fin part 5 .
The retardation and interlocking that occurs will now be more explicitly described with reference to FIGS. 5-11. FIGS. 5-11 are highly enlarged sections of those parts that interact during retardation, i.e. the sleeve 2 , the rear end of the penetrator 1 including the shoulder 3 and the control fin part 5 including the shoulder 6 . The figures are an animation sequence that is to illustrate the progressive deformation that occurs in a conceived longitudinal element of the sleeve 2 . Seven phases of the deformation are shown.
FIG. 5 shows the situation when the shoulder 3 on the penetrator 1 hits the sleeve 2 . It is to be noted that the penetrator 1 also may include a groove 4 , or recess, adjacent to the shoulder 3 and this groove 4 is facing radially inwards. Correspondingly may the control fin part 5 have a groove 7 , or recess, adjacent to the shoulder 6 and this groove 7 is facing radially outwards. The groves 4 , 7 shall have the function that the respective ends of the sleeve 2 are deformed into the grooves and provide a safer axial and radial locking of the penetrator 1 to the control fin part 5 . The grooves 4 , 7 extend circumferentially in the same way as the shoulders 3 , 6 .
It is further to be understood that in respect of the missile can the sleeve 2 , the external surface of the penetrator 1 and the internal surface of the control fin part 5 , have cylindrical surfaces (machined), optionally polygonal surfaces (milled) or serrated or rough surfaces. The surfaces may also differ from each other such that the sleeve for instance is cylindrical while the other two surfaces are serrated or polygonal, or one is serrated while the other is polygonal. These optional surfaces may also be confined to only apply for the bottom surface of the grooves 4 , 7 .
FIG. 6 shows a stage where the deformation of the sleeve 2 is initiated and the retardation of the penetrator 1 occurs. As illustrated in FIGS. 6 and 7 do the ends of the sleeve 2 curl into the respective grooves 4 , 7 simultaneously with that the sleeve 2 commence buckling in the intermediate part thereof.
FIG. 8 shows further deformation of the sleeve 2 and further braking and retardation of the penetrator 1 occurs. Further curling up of the sleeve 2 in the grooves 4 , 7 proceeds while the intermediate part of the sleeve 2 undergoes additional buckling.
FIG. 9 shows still more buckling of the sleeve 2 and FIG. 10 shows the state of the sleeve 2 just before the penetrator 1 is totally braked. The braking may, as an example, happen over a length of 10-15 mm with a sleeve 2 having a length of 20 mm.
FIG. 11 shows the ultimate deformation of the sleeve 2 when the penetrator 1 is completely braked. The respective bucklings have now hit the external surface of the penetrator 1 and the internal surface of the control fin part 5 and have been forced to fixed engagement with respective surfaces. The crest and valley of the folds form knife like edges that bite into the respective surfaces. By certain configuration and material selection of the sleeve 2 , these knife like edges are enabled to orient more randomly than to be lying in a radial plan only. This is material in order to lock the penetrator 1 to the control fin part 5 not only in an axial direction, but also such that locking against mutual rotation between the parts occur.
It is to be noted that the configuration or design of the sleeve 2 together with the selection of materials will be deciding for in which way the sleeve will be deformed. The essential is to achieve a jagged internal and external structure having good interlocking properties against the respective internal and external surfaces on the bodies 1 , 5 . The jagged structure can preferably consist of a large number of short knife like edges having a more or less random orientation such that secure interlocking between the bodies 1 , 5 is achieved both axially and in respect of mutual rotation between the parts.
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A retarding and locking mechanism for use between two mutually translatable bodies. A first body can be induced into motion and guided into a second body and, after a predetermined movement of the first body, the first body is subject to retardation and interlocked to the second body, such that the first and second bodies together form a unitary, integrated body. The first body has a radially outwardly directed shoulder and the second body has a radially inwardly directed shoulder corresponding to the radially outwardly directed shoulder of the first body. A compressible element is provided between the shoulders of the first and second bodies.
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This is a continuation of U.S. patent application Ser. No. 08/386,007, filed Feb. 9, 1995, which is a continuation of U.S. patent application Ser. No. 08/151,255 filed Nov. 12, 1993, now U.S. Pat. No. 5,600,897; and further wherein this instant application is a continuation of U.S. patent application Ser. No. 08/102,766 filed Aug. 6, 1993, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a dryer section for the drying of traveling web, preferably as part of a paper manufacturing machine.
The invention relates to a dryer section having a mix of single-tier and double-tier dryer groups as known, for example, from U.S. Pat. No. 5,232,554 the contents of which are incorporated by reference herein. Such a dryer section is divided into a plurality of successive dryer groups. Each of these dryer groups comprises a plurality of heatable dryer cylinders which come into contact with the web and which are coupled to a (preferably) common drive. The art distinguishes between double-felt (double-tier) and single-felt (single-tier) dryer groups. A single-felt dryer group has only a single endless felt (or a single endless wire). This felt travels together with the web alternately over the drying cylinders and guide or transfer rolls that are preferably designed as suction rolls and which are located between the drying cylinders. Such single-felt dryer groups are customarily arranged at the starting portion of the dryer section to which the web to be dried is fed in a condition in which the web is still relatively wet (solids content: about 35-55%, depending inter alia on the paper grade and machine speed). On the other hand, one or more double-felt dryer groups are customarily provided in the final region of the dryer section. Each of these dryer groups has an upper row of cylinders and a lower row of cylinders, the web travelling alternately over the upper and lower cylinders. The one or more double-felt dryer groups may be arranged directly behind a single-felt dryer group. As an alternative, an additional device (e.g. a size press or an intermediate calender) may be interposed.
Prior art drying sections deploying a mix of single and double-tier dryer groups (hereinafter "mixed drying section") are essentially of two types. In accordance with a first type, the dryer cylinders belonging to the single-tier group or groups constitute a relatively small portion, e.g. about 20% of the total drying surface traversed by the paper web through the entire drying section. In other words, about 80% of the total drying surface is comprised of the dryer cylinders in the double-tier dryer groups.
In the second type of a mixed drying section, substantially most of the total drying surface traversed by the paper web, i.e. more than about 75%, is comprised of the surfaces of the dryer cylinders which belong to the single-tier dryer groups. The remaining 25% is located in the double-tier drying cylinders. In other words, prior art mixed drying sections either are overwhelmingly single-tier or overwhelmingly double-tier. The prior art has not focused attention on the question whether there is an optimal mix that should be provided between the number of single-tier drying cylinders and double-tier drying cylinders and, if so, the precise number of cylinders of each type which should be provided.
The present invention also relates to a method as well as to a device for transferring a strip of paper, i.e. a paper web foil, from a first treatment station (dryer section) to a second treatment station in a paper machine. The following prior art is known:
(1) Federal Republic of Germany 43 28 554 A1
(2) Federal Republic of Germany 39 41 242 A1
Reference (1) shows and describes a dry end of a paper machine. This dry end has, in a first section, a single-row dryer group with a single felt. The felt, with the web resting on it, travels alternately over drying cylinders and guide suction rolls.
In a second section, the dry end has two rows of drying cylinders with two felts. In this case, the web travels alternately over the lower and upper cylinders.
Upon the starting, i.e. threading, of the paper machine, a narrow edge strip (called a tail) is first passed through the entire dry end. Blast nozzles serve in this connection for the transfer of the foil from one drying cylinder to the other.
The blast nozzles produce air jets which extend substantially in the direction of transfer of the edge strip. The air jets thus drive the edge strip in the desired direction, namely from a first (upstream) drying cylinder to a second (downstream) drying cylinder in order to transfer the edge strip from the first drying cylinder to the second drying cylinder.
This transfer has always been a problem. It frequently was not possible to directly transfer the edge strip at given places. At times, there is a fluttering of the edge strip so that the entire process of the passing of the edge strip is time-consuming. This, however, means relatively long downtime of the paper machine, and thus reduced production.
Reference (2) also shows and describes the transfer of a narrow edge strip in the dry end of a paper machine. In this case, a jet of air is produced which is directed opposite the direction of travel of the web of paper. However, this reference does not describe a free, i.e., open-chain transfer of the paper strip. Rather, the paper strip adheres to the outer surface of a cylinder and is scraped from the latter by a scraper, the blast air supporting the detachment.
SUMMARY OF THE INVENTION
One aspect of the present invention is concerned with the precise ratio of single-tier and double-tier drying cylinders that are to be provided in a drying section. The inventors herein reject the prior art conventional wisdom which provides too few single-tier drying cylinders, since that approach ignores problems of runnability--too many paper breaks--and greater difficulty in threading. On the other hand, the inventors discovered that configuring a dryer section entirely of single-tier dryer groups, or even overwhelmingly of single-tier groups, ignores significant advantages provided by double-tier dryer groups. Advantages of double-tier dryer groups include: ease of providing a tail cutter function; avoidance of paper bursting at certain dryness levels; achieving shorter building lengths; assuring no felt or fabric tearing and significantly reduced fabric wear; lower machine fabrication costs as compared to a total single-tier or an overwhelmingly single-tier construction; lower operating costs (steam expenditures and the like) than with total single-tier; improved overall paper quality; and enhanced visibility and control of the open draws of the paper.
Another aspect of the present invention is concerned with the problem of threading of the web to be dried into the dryer section. As is known, the following is provided for this purpose. The web which is formed and mechanically dewatered in the initial part of the paper manufacturing machine travels during the starting (threading) phase at full operating speed, but temporarily only up to the end of the press section or up to the first dryer cylinder of the dryer section. From there, it passes downward into a broke pulper. A narrow edge strip, referred hereinbelow as a "striplet" or "tail" is now separated from the web. It is passed first of all through the single-felt dryer group or groups (generally several are present). It is known that this can be done without the aid of ropes. In other words, an automatic ropeless tail guide device, i.e., a tail threading device, is present. For example, the tail is detached from the individual cylinders by means of a scraper which is combined with an air-blow nozzle. Furthermore, special edge suction chambers are provided in the transfer suction rolls, a relatively high vacuum being produced in said chambers during the tail threading process, independently of the other part of the guide suction roll.
In contrast, in accordance with Federal Republic of Germany 4037661 (which is an equivalent to said U.S. Pat. No. 5,232,554), a rope guide is provided for the threading of the tail in the subsequently located double-felt dryer group or groups. This arrangement has disadvantages. It can cause operational disturbances. The tail can slip off the rope. Further, the tail is not guided with sufficient precision. Tearing of the rope is also possible. It is therefore desirable to completely avoid rope guides in the entire dryer section of modern paper manufacturing machines. This is particularly true at the increasingly greater operating speeds encountered nowadays (on the order of magnitude of 1500 to 2500 m/min).
In order to achieve this object, an automatic ropeless tail guide device is provided in accordance with the invention in the double-felt dryer group or groups. Examples of parts of different constructions suitable for this are described in the following publications:
Federal Republic of Germany Patent 1 245 278;
Federal Republic of Germany Utility Model 8 914 079; and
Federal Republic of Germany Utility Model 9 109 313.
Experiments have shown that the reliability of pneumatically acting parts is less than Satisfactory when the solids content of the web is still relatively low. Above a certain solids content and taking into account other factors, and depending on the paper grade and other parameters, however, these pneumatically acting parts operate well.
The inventors herein have studied the problems encountered in transferring a paper web from a single-tier to a double-tier dryer group and the operational difficulties encountered in threading a paper web through a double-tier dryer group and have found that an optimal transfer from a single-tier dryer group to the double-tier dryer group(s) depends on various parameters including: paper grade; stiffness of the paper web, particularly of the transfer tail; strength of the paper web, particularly of the transfer tail; dryness, i.e., solids content, of the paper web; operating speeds; basis weight of the paper web; desired paper properties in the final paper product; and runnability. The results will be discussed in detail later, in connection with a transfer point table presented in the Detailed Description section of the instant specification.
For rebuilds, costs and other considerations should be taken into account. One consideration is machine down time during a machine rebuild. It should be as short as possible, to have the least impact on paper production. Consonant with this objective, only one or perhaps two groups of an old double-tier machine might be converted to single-tier. The desire to keep the down time as short as possible might militate in favor of selecting a transfer point low in the range of possible values, or at the point between the first possible transfer point and the optimal transfer point, shown in the aforementioned transfer point table.
According to the invention, with some of the paper grades the transfer of the paper web into the double-felt dryer groups should occur at a point where the paper web has already traversed about 30-60% of the paper web contacting surface of the entire drying section. For example, a drying section including a total of 40 drying cylinders of same diameters, of which 21 are in the single-tier section and 19 in the double-tier section, meets the condition since, at the end of the single-tier dryer groups, the paper web will have traversed more than 50% of the total surface of all the drying cylinders.
In order to reliably automatically thread the paper web from the single-tier groups to and through the open draws of the double-tier groups the invention relies on two advantageous factors. First, with the conditions set forth above, the paper web develops a stiffness and firmness that is high enough for threading purposes. Second, again with the conditions set forth above, the paper web will not tend to adhere to the surface of the drying cylinders of the double-tier group or groups because the adhesion force decreases after the wet web has passed approximately 20-30% of the web contacting surface of the dryer section. By operating in accordance with the invention, the paper web is in the double-tier group(s) at a state where its adhesion to the drying cylinders is low enough to assure both good runnability and reliable automatic (ropeless) tail threading.
By constructing the drying section to include a mix of single and double-tier groups, the invention significantly shortens the overall length of the drying section, resulting in savings in machine and building costs, compared with a total single-tier configuration. The invention further obtains an optimal and prompt transfer point for the paper web between the single and double dryer groups.
In column 7, lines 10-40 of U.S. Pat. No. 4,232,544 measures are described for further conducting the oncoming tail in the known dryer section within the region of the end of the single-felt dryer group, not into the double-felt dryer group but rather temporarily into the cellar or other locations or receiving bins associated with the paper machine. Only after stable travel of the tail through the single-felt dryer group or groups has been obtained is the tail then conducted further into the double-felt dryer group or groups. The contents of U.S. Pat. No. 4,232,544 are incorporated by reference herein.
Another aspect of the invention concerns advantageous arrangements of the cylinders and felt guide rolls in the transition region between the last single-felt dryer group and the directly or indirectly following double-felt dryer group. It is particularly favorable if the web passes substantially downward through the place of separation between the two dryer groups.
Still another aspect of the invention is concerned with the problem of the removal of broke, which occasionally is produced in the event of a tear in the paper web. This task, which can never be entirely excluded, is present, in particular, in the initial region of the dryer section, i.e. in the region of the single-felt dryer groups. It is best if all single-felt dryer groups are felted on top. In such a case, the paper broke can simply fall downward under the force of gravity, in particular with arrangement of the cylinders in horizontal rows, as generally customary.
If, however, in order to obtain the most uniform possible properties on both sides of the finished web of paper, it is desired that both sides of the web of paper alternately contact the dryer cylinders, not only in the double-felt dryer group but also in the region of the single-felt dryer groups, then an arrangement of the cylinders in vertical or V-shaped rows is particularly advantageous. In this connection, reference is made to U.S. Pat. Nos. 5,050,317 and 5,177,880, the contents of which are incorporated by reference herein. The latter describes inter alia a dryer-section configuration having a plurality of V-shaped dryer groups felted on top and having two bottom-felted dryer groups in the shape of a V, and arranged to provide an optional gap that can be opened for the removal of broke between the lowermost cylinders of these two dryer groups.
If the above-mentioned transfer rolls required in the single-felt dryer group are designed as suction rolls, they can be provided with an inner stationary suction box which can also serve for defining a desired suction zone for threading. However, a construction is preferred in which the inside of the transfer suction rolls is free of stationary inserts. Furthermore, a hollow journal serving for the drawing-off of air is not necessary in order to provide a vacuum inside the roll. Rather, an external suction box is provided (for example, in the pocket between two adjacent dryer cylinders).
A final aspect of the invention is concerned with the problem of the height above a horizontal reference plane at which the axes of rotation of the cylinders and/or guide rolls of the single-felt dryer group or groups are advantageously arranged, for instance with respect to the required free evaporation path for the paper web between two cylinders. Another factor is the arrangement of these axes of rotation relative to the planes in which the axes of rotation of the cylinders of the following double-felt dryer group lie.
It is common to all the various embodiments of the invention that at least one double-felt dryer group is always present in the region of the end of the dryer section. The following advantages (some already mentioned) result from this:
1. Uniform quality of the paper, particularly approximately equal properties of the surface on both sides of the paper, which uniform quality is also obtained in the cross machine direction, obtaining improved printability and reduction of curl tendencies in comparison to paper produced with a total single-tier configuration;
2. Even if a very high final solids content is desired (on the order of 98%), there is no danger of tearing (or breaking) of the paper web since longitudinal stresses are relieved in the double-felt group;
3. The tail cutter required at the end of the dryer section can be readily arranged in the traditional manner in the double-felt dryer group;
4. No rope guide for the pulling-in of the tail is required at any place in the entire dryer section; and
5. Wear of the felts (sometimes observed in the end region of known dryer sections which have exclusively single-felt dryer groups) is avoided by the presence of the double-felt dryer groups.
The present invention is also concerned with providing a method and a device for transferring a strip of paper from a first treatment station (dryer Section) to a second treatment station, and particularly from a first drying cylinder to a second drying cylinder in order to permit the transfer with greater reliability and higher speed.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 to 4 show diagrammatic side views of several different dryer section having a plurality of single-felt dryer groups and at least one subsequent double-felt dryer group;
FIGS. 5 to 8 show diagrammatic side views (on a larger scale than in FIGS. 1 to 4) of the web transfer zone between a single-felt dryer group and a following double-felt dryer group having a corresponding tail guide means;
FIGS. 9 to 11 are similar to FIGS. 5 to 8 and show different vertical distances between the axes of the cylinders or guide rolls and a reference plane;
FIGS. 12 and 13 show other embodiments in a diagrammatic side view;
FIG. 14 graphically illustrates the transfer air jet directions in the web transfer regions.
FIG. 15 illustrates yet another possible planar alignment between single-tier and double-tier groups; and
FIG. 16 shows a further embodiment of the invention, in a diagrammatic side view.
FIG. 17 graphically illustrates transfer air jets provided between two top-felted single-tier dryer sections.
FIGS. 18A-18D illustrate web transfer arrangements between a bottom felted single-tier leading into a double-tier dryer group and further show different vertical alignments between the axes of the cylinders and guide rolls to a reference plane as well as the height alignment between the cylinders and guide rolls in the adjacent single-tier and double-tier dryer groups;
DETAILED DESCRIPTION OF THE INVENTION
The dryer section shown in FIG. 1 has located first in the path of the paper web six single-felt dryer groups 11-16, arranged one behind the other. Each of these dryer groups has a single endless felt F. For example, in the first dryer group 11, the felt F travels together with the web 9 alternately over dryer cylinders 51 and guide suction rolls 51'. In the first two dryer groups 11 and 12, as well as in the fourth and sixth dryer groups 14 and 16, the bottom of the web comes in contact with the cylinders. Accordingly, the dryer cylinders 51, 52, 54 and 56 lie in this embodiment above the corresponding guide suction rolls 51', 52', 54' and 56', respectively. The cylinders are in this case "top-felted". This is different in the third dryer group 13 and in the fifth dryer group 18. Here the cylinders 53, 55 contact the top side of the web. They are therefore "bottom-felted" and lie' below the corresponding guide suction rolls 53', 55'. Accordingly, the paper web transfer regions between the dryer groups 12 to 16 are developed using web reversal mechanisms. For the details of these web reversal mechanisms, reference is made to U.S. patent application Ser. No. 867,411, filed Apr. 13, 1992, the contents of which are incorporated by reference herein.
It can be noted from FIG. 1 that at each of these web regions, the paper web 9 forms a short open draw; i.e. it is temporarily not supported by a felt. In the region of a small suction zone of a transfer roll 58, it travels in each case onto the next felt. In FIG. 1, these transfer rolls 58 are the sole suction rolls having internal stationary suction boxes. The guide suction rolls 51' to 56', on the other hand, do not have inner stationary inserts or direct suction connections. Rather, an external suction box 59 is provided on each of these transfer suction rolls. This box lies in the pocket between two adjacent dryer cylinders and has a ledge 60 (see FIG. 7) at the place where felt F and web 9 leave-together the first of these two cylinders, the ledge 60 stripping off and diverting the layer of boundary air-carried along by the felt.
The last single-felt dryer group 16 is followed by a double-felt dryer group 17 having several bottom cylinders 57 and several top cylinders 57', as well as a bottom felt UF and a top felt OF. Here, the web 9 travels meandering between the lower and upper cylinders. In FIG. 1, a tail cutter S is indicated between the last two cylinders.
The dryer section shown in FIG. 2 has for instance three (or four or five) single-felt dryer groups 21-23; however, in contrast to FIG. 1, they are all top-felted. In other words, all dryer cylinders 71-73 contact the bottom side of the web. Another difference from FIG. 1 is that the guide suction rolls 71' to 73' have inner stationary suction boxes and are arranged at only a slight distance from the adjacent dryer cylinders. Furthermore, for example, two (or three) double-felt dryer groups 24, 25 are provided with bottom cylinders 74, 75 and with top cylinders 74' and 75'.
The dryer sections of FIGS. 1 and 2 have only horizontal rows of cylinders. In FIGS. 3 and 4, however, in order to shorten the overall structural length of the dryer section, the cylinders of the single-felt dryer groups are arranged in several rows which are inclined to the vertical direction, with rows inclined rearward alternating with rows that are inclined forwards. In accordance with FIG. 3, two V-shaped double rows form a first group 31 and a second dryer group 32. The cylinders 81, 82 of these two dryer groups are top-felted. This is followed by two bottom-felted dryer groups 33, 34. For example, the three (or four) cylinders 83 of the third dryer group form a rearward inclined row. On the other hand, the cylinders 84 of the fourth dryer group form a forward inclined row.
Between the lowermost cylinders of these two dryer groups 33, 34, a slot or gap can be opened by a swingable felt guide roll 87, in order to remove broke in the downward direction. The fifth dryer group 35 again has solely top-felted dryer cylinders 85, which again form a V-shaped double row. Behind the last cylinder of this dryer group 35, the web is guided obliquely downward to the first lower cylinder 86 of the following double-felt dryer group 36. In accordance with FIG. 4, solely top-felted and V-shaped single-felt dryer groups 41, 42 and 43 are present, followed by two double-felt dryer groups 44 and 45. In both FIGS. 3 and 4 all transfer suction rolls 81' to 85' and 91' to 93' which are located in the corresponding dryer group between two cylinders are arranged at a larger distance from these cylinders and are provided with external suction boxes. This manner of construction does not merely involve less expense. It furthermore also saves drying section energy since a longer free evaporation path is-present between every two cylinders so that the drying is more economical. These latter factors apply also to the arrangement in accordance with FIG. 1.
FIG. 5 shows, in the case of another dry end, the transfer region between the last single-felt dryer group and the first double-felt dryer group. There can be noted here the last two drying cylinders 73 of the last single-felt dryer group 23 and the first three cylinders 74, 74' of the double-felt dryer group 24. There can furthermore be noted a guide suction roll 73' provided with inner suction box and, in front of the first lower drying cylinder 74, a transverse suction roll 58, also having a stationary inner suction box. An automatic rope-less edge-strip guide device is formed in the single-felt dryer group 23, for instance in the manner that each guide suction roll 73 has a known edge-suction zone on one of its two ends. Furthermore, airblast devices are provided on a scraper support body 76, which devices are indicated symbolically by arrows, as well as an air blast nozzle 79. At the place where the web 9 and the felt F jointly leave the last cylinder 73, an edge suction box R (active only in the region of the edge strip), web stabilizer, or the like, can be arranged. Or, a short "edge-strip guide scraper" 88 which covers only the region of the edge strip and which may also have an air-blast nozzle, is arranged on the last cylinder 73.
The blast nozzles 101, 102, 103, 104 shown in FIG. 5 are absolutely decisive. They serve for the transferring of an edge strip from the first lower drying cylinder 74 of the double-felt dryer group 24 to the first upper drying cylinder 74' thereof. As can be seen, on both sides of the edge strip 9, there are blast nozzles 101, 103, the air jets of which are directed upward, .i.e., in the direction of transfer, as well as blast nozzles 102, 104, the air jets of which are directed downward and thus opposite the direction of transfer. The inventor has found that, in this way, an extremely stable guiding of the edge strip is possible. The air jets of the nozzles 101, 102 produce a conveying action in that they rapidly carry the edge strip along in upward direction to the drying cylinder 74'. The air jets of the two blast nozzles 102, 104, on the other hand, see to it that the edge strip assumes a stable position and, immediately after leaving the first lower drying cylinder 74 of the dryer group 24, assumes the correct direction to the first upper drying cylinder 74'.
The two blast nozzles 101, 102, as well as the two blast nozzles 103, 104, can be structurally combined, being thus borne by a single bracket.
In FIG. 14 the transfer region is again shown, on a larger scale. Again, the blast nozzles 102, 104 can be noted. The blast nozzles 101, 103 have been omitted for greater clarity of the drawing. As can be seen, air jet 102.1 from blast nozzle 102 has a component 102.2 which is perpendicular to the direction of the edge strip 9, and a component 102.3 which is exactly opposite to the direction of the edge strip 9. Exactly the same is true with respect to the air jets 104.1 from blast nozzle 104 having the components 104.2 and 104.3.
It should be appreciated that the rope-less web transfer over an open draw illustrated and described above with reference to FIGS. 5 and 14 can be applied between individual dryers of a double-tier dryer, between single-tier and double-tier dryers and between single-tier dryer groups. In fact, it can be applied anywhere where the paper web encounters an open draw path. See, for example, FIG. 17.
In accordance with FIG. 6, the following is provided between the last cylinder 73 of the single-felt dryer group 23 and the first lower cylinder 74 of the double-felt dryer group 24: A guide roll 18 for the felt F and a guide roll 19 for the bottom felt UF are so arranged that the felts overlap each other. During normal operation, a certain distance is present between the felts F and UF so that the web 9 travels freely, i.e., in an open draw, not supported by the felt F, from the cylinder 73 to the felt guide roll 19. During the threading of the tail, the guide roll 18 can be brought into the position shown in dash-dot lines so that the felts F and UF temporarily contact or almost contact each other. A tail guide scraper 88 can furthermore be provided.
In FIGS. 7 and 8, the first cylinder 94' of the double-felt dryer group is an upper cylinder. Therefore a guide suction roll or reversing suction roll 96 is provided between it and the last cylinder 93 of the single-felt dryer group. This suction roll 96 can, as shown in FIG. 7, lie in the loop of the felt F of the single-felt dryer group, the felt F being tangent to the upper cylinder 94' and transferring the web 9 to it. In accordance with FIG. 8, the guide suction roll 96' can lie in the top felt of the double-felt dryer group. This felt tangentially contacts the last cylinder 93 of the single-felt dryer group and receives the web from it. An automatic ropeless tail guide device in the form of tail guide scrapers 88 and in the form of blow nozzles (represented symbolically by arrows) which are arranged on scraper support members 77 or on a separate blow pipe 87 can again be clearly noted in FIGS. 7 and 8. In order that the bottom felt UP which travels in the direction towards the first upper cylinder 94' does not unnecessarily convey air into the pocket T, an additional felt guide roll 100 (or an air scraper) can be provided.
In FIG. 9 a larger distance H--as compared with FIG. 1--is provided between the planes E1 and E2 whereby an enlarged evaporation path is available for the web 9 between every two cylinders of the single-felt dryer group. The axes of the cylinders lie in plane El, while the axes of the transfer suction rolls, and at least approximately the axes of the lower cylinders of the double-felt dryer group, lie in plane E2.
In accordance with FIG. 10 the following is provided, differing from FIGS. 1 and 2. The axes of the cylinders of the single-felt dryer group lie in the same horizontal plane E1 as the axes of the upper cylinders of the double-felt dryer group. Thus uniform stands 89 can be provided for all of these cylinders. Furthermore, in this way, the axes of the cylinders of the single-felt dryer group lie at a greater vertical distance HO above a reference plane EO than, for instance, the cylinders 56 in FIG. 1. It follows from this that the vertical distance H between the transfer suction rolls and the cylinders can be selected to be very large if evaporation paths still larger than in FIG. 9 are necessary between the cylinders. In this connection, the axes of the transfer suction rolls (indicated in dot-dash line) again lie at least approximately in the same horizontal plane E2 as the axes of the lower cylinders of the double-felt dryer group. The advantages described can be further increased if, in accordance with FIG. 11, the axes of the cylinders of the single-felt dryer group (plane El) are arranged above the axes of the upper cylinders of the double-felt dryer groups (plane E3).
FIG. 12 shows an alternative to FIG. 1. The double-felt dryer group 17A is developed as follows in accordance with Federal Republic of Germany Patent 3 623 971. The paper web 9 travels first over a lower cylinder 61 and then, in succession, over two top cylinders 62 and then in succession over two bottom cylinders 63 and then, in succession, over the upper cylinders 64 and then in succession over two lower cylinders 65 and finally over an upper cylinder 66.
A guide suction roll 62'-65' is arranged between the cylinders of each cylinder pair 62-65. In this way, the number of open draws of the paper web between the two horizontal rows of cylinders is reduced by approximately one half. The threading of the tail can take place automatically in exactly the same manner as described above with reference to FIGS. 5 and 7, and therefore without ropes. Any paper broke obtained is automatically transported to the rear end of the dryer group 17A and pushed out there.
FIG. 13 shows that a bottom felted single-felt dryer group 15A can also be arranged directly in front or a double-felt dryer group 16A. In accordance with another alternative, each lower cylinder 67, 68 in the double-felt dryer group 16A has its own felt FA, FB in order to facilitate the discharge of broke. Note that the lower cylinders 67, 68 of the double-felt dryer group are horizontally aligned (same height) with the dryer cylinders of the preceding single-tier group.
Different from FIGS. 1-13, further equipment may be disposed between two of the dryer groups, e.g. between the last single-felt and the first double-felt dryer group.
With reference to FIGS. 18A-18D, various Web transfer arrangements for transferring a paper web from a bottom felted single-tier to a double-tier dryer group are illustrated. In FIG. 18A, the cylinders of the single-tier dryer groups lie in a plane II, its vacuum rolls in a plane III, and both planes II and II are located between the planes IV and V respectively of the top and bottom dryer cylinders of the succeeding double-tier group.
The paper web 208 travels in a generally straight upward path from the last dryer cylinder 200 of the single-tier group to the leading top cylinder 202 of the double-tier group. The felt rolls 204 and 208 (of the single-tier and double-tier groups respectively), are situated close to one another to provide a relatively short open draw for the paper web at the transfer region. Note further that the diameter of the cylinders in the double-tier group is somewhat smaller than the cylinders in the double-tier group. This provides several advantages. It enables easier access to the pocket areas P1, P2, P3 between the top and bottom cylinders in the double-tier group. Further, if desired, it permits placement of the top and bottom cylinders closer to one another to reduce the size of the open draws of the paper web between the upper and lower cylinders in the double-tier dryer group. It also reduces the height above the floor of the upper cylinders 202, enhancing accessibility and servicing of the machine.
In accordance with FIG. 18B, the felt 220 of the bottom cylinders 212, 212' of the double-tier group makes a lick-up, tangent contact with the trailing cylinder 200 of the single-tier group at a point LU, where the paper web transfers to the felt 220, and thereafter guided around the vacuum roll 210 toward the leading bottom cylinder 212. During threading, an air nozzle or similar device 216 produces a jet of air to ensure that the leading end, i.e. tail, of the paper web continues with the felt 220. Air nozzle 216 can be supported on an arm which is connected at a pivoting mechanism 218 so that it can be removed from its illustrated location close to the cylinder, for example in order to facilitate the removal of broke from atop the cylinder 200.
In accordance with FIG. 18C, the path of the paper web from the trailing cylinder 200 is toward the felt roll 224 and thereafter across a relatively short open draw 226 to a leading vacuum roll 222 toward the leading top cylinder of the double-tier group. The vacuum roll 222 is provided with a relatively short vacuum zone 228 to support the paper web against the felt 230 that is associated with a double-tier group.
FIG. 18D has an arrangement of drying cylinders and vacuum rolls as in FIG. 18B but differs therefrom in that the illustrated vacuum roll 232 is felted by the felt of the single-tier group and carriers the paper web to a lick-down, tangent contact with the leading bottom cylinder 212 of the double-tier group.
FIG. 15 illustrates an arrangement wherein the paper web travels first through several single-tier dryer groups arranged alternatingly as a top felted single-tier group 240 followed by a bottom felted single-tier group 242, thence a top felted single-tier group 244 and terminating in a double-tier group 246. Note that in this arrangement the dryer cylinders of all of the top felted single-tier groups i.e. in the same plane as the cylinders of the upper tier of cylinders in the double-tier group 246. Similarly, the cylinders of the bottom felted dryer group 242 have their axis of rotation in the same horizontal plane as the axis of rotation of the bottom cylinders of the double-tier group.
In FIG. 16, a further aspect of the invention is disclosed. The configuration shown in FIG. 16 is similar to that of FIG. 5 and comprises the last two dryer cylinders 73 of the last single-tier dryer group 23 having one felt and the first six cylinders 74, 75' of the first double-tier dryer group 24 having an upper felt OF and a lower felt UF as well as upper felt rolls 199 and lower felt rolls 198 with each felt roll being positioned between two adjacent dryer cylinders.
Either the upper felt rolls 199 or the lower felt rolls 198 are formed as suction rolls. (In a further alternative, all felt rolls 198 and 199 may be formed as suction rolls). In the embodiment shown, only the lower felt rolls 198 are suction rolls and are connected via suction lines 197 (comprising a control valve 196) to a suction blower 195. In operation, the lower suction felt rolls 198 remove moist air from every other pocket 194, namely from the pockets which are below the upper cylinders 74' and which "contact", i.e. which face, the bottom side of the paper web 9. Thus the evaporation of the bottom web side is being enhanced relative to the evaporation of the top web side. That mode of operation is able to eliminate any tendency of curl of the finished paper web which curl may result from the last single-tier dryer groups 23 or from other factors. More specifically, the enhanced evaporation of the bottom side of the web 9 counteracts a tendency of upward-curl, if any.
Accordingly, if there is a tendency of downward curl of the finished paper web, then additional moisture removal should be caused from the pockets 193 which are positioned above the lower cylinders 74. For that purpose the upper felt rolls 199 should be suction rolls (not shown in FIG. 16). If one cannot predict, whether there will be the tendency of upward-curl or of downward-curl, then all felt rolls 198 and 199 should be suction rolls in that case, the lower suction felt rolls 198 should be controllable by control valve 196 as shown in FIG. 20 and the upper suction felt rolls 199 should have a separate suction line (not shown) with a further control valve. It is then possible to enhance the evaporation of either the top side or the bottom side of the paper web 9 depending on the type of curl (downward or upward-curl) that occurs.
Instead of providing suction felt rolls, there are other possibilities to control the amount of evaporation of the two sides of the paper web. For example, if the drying cylinders are equipped with doctors (see FIG. 5), moist air may be removed through the hollow doctor beams. Another possibility is to blow dry air either into the pockets 194 which are positioned below the upper cylinders 74' or into the pockets 193 which are above the lower cylinders 74. For that purpose, air blowing devices (not shown) will be positioned below the lower felt rolls 198 and/or above the upper felt rolls 199 which devices blow dry air through the lower felt UF and/or the upper felt OF into the respective pockets 193/194. Such blowing devices per se are known to those skilled in the art.
The lower suction felt rolls 198 shown in FIG. 16 have a further advantage. If a web breakage occurs, paper broke is automatically transported--with the aid of the negative pressure in the lower suction felt rolls 198 from one lower cylinder 74 to the next lower cylinder 74 up to the end of the double-tier drying group 24. In that case of web breakage, the control valve of upper suction felt rolls, If those are present, should be immediately closed.
The suction felt rolls 198 have, as usual, a perforated roll shell and an internal suction which defines a suction zone 190, as schematically depicted. Note that the suction zone 190 is open to the adjacent pocket 194 and that there must be a distance "d" between the normal path of web 9 and the suction zone 190. Thereby it is avoided that the web might travel together with felt UF around the suction felt roll 198.
While FIG. 16 depicts one particular position for the lower suction rolls 198, the foregoing advantages are also attained when the felt suction rolls 198 are symmetrically disposed between the lower cylinders 74, as illustrated for example in FIG. 11.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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In a drying section of a paper making machine, the paper web is conducted through a plurality of single tier dryer sections and then transferred to at least one final double tier dryer section for completing the drying process. The paper web is threaded through the open draw between the single tier dryer sections and the double tier dryer section and through the open draws between the lower cylinders and the upper cylinders in the double tier dryer section by use of air jets which blow at the paper web from opposite sides thereof. The air jets include at least one jet which blows in a direction generally opposite to that of the paper web.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of patent application Ser. No. 10/139,862 filed on May 6, 2002, now allowed, which is a continuation of patent application Ser. No. 09/549,217, entitled “A Method for Treating Acne” filed on Apr. 13, 2000, now U.S. Pat. No. 6,408,212, which claims priority from U.S. provisional patent application No. 60/129,136, entitled, “A Method for Treating and Preventing Acne and Method for Preserving Skin Elasticity” filed Apr. 13, 1999, all of which are assigned to the assignee of the present patent application and are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the application of energy to biological tissue, and specifically to the application of electromagnetic energy to the skin.
BACKGROUND OF THE INVENTION
[0003] It is known in the art to apply electromagnetic energy to biological tissue to engender changes therein. Sunbathers, for example, regularly expose themselves to bright sunlight in order to increase melanocyte activity in the basal layer of the epidermis, responsive to the sun's ultraviolet (UV) radiation. Artificial UV sources have been created to satisfy the desire for a “healthy”-looking tan in the winter. Other forms of electromagnetic energy, laser-light in particular, are currently used in a large range of therapeutic and cosmetic procedures, including eye surgery, hair removal, wrinkle removal, and tattoo removal.
[0004] PCT publication WO 98/55035, which is incorporated herein by reference, describes methods for minimizing injury to biological tissue surrounding a site exposed to pulses of electromagnetic energy.
[0005] U.S. Pat. No. 5,720,894 to Neev et al., which is incorporated herein by reference, describes biological tissue processing using Ultrashort Pulse High Repetition Rate Laser System for Biological Tissue Processing.
OBJECTS AND SUMMARY OF THE INVENTION
[0006] It is an object of some aspects of the present invention to provide improved apparatus and methods for applying energy to a material.
[0007] It is another object of some aspects of the present invention to provide improved apparatus and methods for removing heat generated during application of electromagnetic energy to a material.
[0008] It is a further object of some aspects of the present invention to provide improved apparatus and methods for removing heat generated during application of electromagnetic energy to biological tissue.
[0009] It is still a further object of some aspects of the present invention to provide improved apparatus and methods for decreasing pain during application of electromagnetic energy to biological tissue.
[0010] It is yet a further object of some aspects of the present invention to provide improved apparatus and methods for performing medical treatments.
[0011] It is also an object of some aspects of the present invention to provide improved apparatus and methods for performing cosmetic treatments.
[0012] It is further an object of some aspects of the present invention to provide improved apparatus and methods for enabling a visible wavelength electromagnetic energy source to perform material and tissue removal and modification.
[0013] It is yet a further object of some aspects of the present invention to provide methods and apparatus for enabling a visible wavelength electromagnetic energy source to perform material and tissue and modification.
[0014] It is also an object of some aspects of the present invention to provide improved methods and apparatus for enabling a low-power electromagnetic energy source to perform tissue removal and modification, substantially without pain, while controlling the amount of damage or modification to remaining tissue.
[0015] It is also an object of some aspects of the present invention to provide improved methods and apparatus for enabling a low-power electromagnetic energy source to remove unwanted hair, substantially without pain, while controlling the amount of damage to remaining tissue.
[0016] It is also an object of some aspects of the present invention to provide improved methods and apparatus for enabling a low-power electromagnetic energy source to perform tissue treatment that prevent the occurrence of acne.
[0017] It is also an object of some aspects of the present invention to provide improved methods and apparatus for enabling a low-power electromagnetic energy source to perform tissue treatment that cures acne and relieves symptoms Df acne.
[0018] In preferred embodiments of the present invention, the tissue of the subject has been treated with high absorbance substance so that substantially only the hair follicle openings retain the absorbing particles. An energy source applies electromagnetic energy to skin tissue of a subject preferably so as to cause an expansion and clearing of the follicle duct opening. The expanding opening thus allows clearing removal of debris and undesired substances within the hair follicles. Tissue mechanical compression is also preferably applied simultaneous or immediately following the heating and follicular ducts opening action in order to enhance removal of unwanted substance from the hair follicles. Excess heat may be removed by applying a coolant or a cooling element to the tissue. Removal of the heat immediately following the application of the energy generally reduces the subject's sensation of the heat, and, in particular, reduces any sensation of pain. Moreover, heat removal typically reduces or eliminates collateral injury to tissue surrounding the ablated area. Typically, although not necessarily, the tissue comprises the subject's skin.
[0019] The tissue of the subject may also be treated by applying a reflecting coating material to the skin area being treated and then removing portions of the reflective coating material proximate a blocked hair follicle, for example, and then applying electromagnetic energy to the skin area being treated. The electromagnetic energy is substantially reflected by the reflective coating so as to protect tissue. Where the reflective coating has been removed, the electromagnetic radiation propagates through the tissue so as to mitigate the blockage of a hair follicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a simplified pictorial illustration of apparatus for treating skin and showing the covering of skin with a substance having high optical and high thermal expansion properties in order to cause the substance to penetrate into hair follicle openings in the skin (hair ducts).
[0021] FIG. 1B is a simplified pictorial illustration showing the removal of the substance from the skin while leaving it in the hair ducts.
[0022] FIG. 1C is a simplified pictorial illustration showing the irradiation of the skin by electromagnetic.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] In preferred embodiments of the present invention, the hair ducts (hair follicle openings) are forced to open so that excess oil and unwanted deposits can be removed from the hair duct.
[0024] To accomplish this, a substance, which can absorb light or electromagnetic energy, is forced into the hair ducts. The light or electromagnetic energy impinging on the target is thus converted into heat. The heated substance expands under the influence of the thermal energy, thus forcing the pores to expand and open, thereby allowing cleaning and drainage of unwanted deposits within the hair duct.
[0025] The expansion process described above, may include any or all of the following:
[0026] Volumetric thermal expansion which is proportional to the inserted/absorbing substance temperature, vaporization, sublimation, rapid vaporization, explosive vaporization, expansion due to plasma formation, expansion due to gas generation, and ablation.
[0027] The high absorbing substance placed in the hair ducts may also become liquefied at some point following the start of the heating and expansion event, thus enabling drainage and cleaning of the hair duct including the substance of high absorption coefficient or high expansion coefficient itself.
[0028] The sequence for the procedure may be as follows:
A) Apply a substance of high absorption to the skin and force said substance down the hair follicle openings. Wipe off excess substance on surface. Irradiate with pulse duration such that no significant heat is transfer to adjacent tissue and ablative interaction occurs at follicle openings. B) Applying a substance of high absorption to the skin and force said substance down the hair follicle. Wipe off excess substance on surface. Irradiate with a pulse duration such that no heat is transferred to adjacent tissue and rapid heating and expansion interaction occurs at follicle openings. Pulse duration can be, for example in the range of about one microsecond and as long as about 100 ms, since at these pulse duration ranges thermal diffusion is from about 1 μm and up to about a few hundred micrometers. Preferred irradiation times are from about 100 microsecond to about 10 millisecond. Such thermal diffusions are acceptable while significant physical expansion of the absorbing substance can be achieved. C) Alternatively, in another embodiment of the present invention, apply a substance of high absorption to the skin and force said substance down the hair follicle openings. Wipe off excess substance on surface.
[0032] Irradiate with pulse duration such that no heat is transferred to adjacent tissue and rapid heating, expansion and melting of “absorbing plug” occurs at follicle openings.
[0033] D) Alternatively, in another embodiment of the present invention, apply a substance of high reflection to the surface of the skin. Force that substance down the hair ducts while ensuring that the particles in said substance are such that they are not capable of penetrating (meaning that they are too large) into any other type of skin pores (such as surface sweat pores) other than the hair follicle openings.
[0034] In an alternative embodiment of the present invention, a substance of high absorption is applied to the surface and is forced down the hair ducts. The particles in said substance are such that they are not capable of penetrating into any other pores on the skin surface. The skin surface is then wiped off to allow substantial removal of said substance from the skin surface. The substance of high absorption, however, remains in the hair duct openings. A source of electromagnetic energy is then allowed to irradiate and subsequently heat and cause expansion to the substance of high absorption at the hair duct openings. Such an expansion allow drainage and cleaning of the hair duct openings.
[0035] An alternative embodiment contemplates a method and apparatus for both the treatment and prevention of occurrence of acne and is disclosed below.
[0036] The method relies on the creation of differential openings in the skin, in particular, differential openings in the human skin.
[0037] The phenomena of acne occurs due to improper drainage of the hair follicle openings (hair ducts). The hair follicle opening ranges in size on the order of from about 50 μm to about 100 μm. The opening of any other pore on the skin is substantially smaller than that. In particular the opening of the sweat pores are less than about 30 μm in diameter.
[0038] The method and apparatus contemplated herein consists of the following steps:
a) In the event that hair is growing out of the targeted skin area, the first step is to remove the hair shaft from the follicle area. Such removal can be accomplished, for example, by means of wax depilation, mechanical removal or chemical removal of the hair from the skin. b) Applying a substantially reflective coating to the skin. The reflective coating comprises a suspension of reflective particles, that are capable of reflecting substantially most of the light impinging on them and absorbing very little of the impinging electromagnetic radiation. For example, metal-based particles could easily reflect 90% of the incident light.
[0041] The reflective particles in the suspension substance should also be of a size that is larger than the size of sweat pores in the skin of the patient. Preferably, the particles in the reflecting substance should be greater than 30 μm. The particles in the suspension particles, however, should be smaller than the size of the hair follicle opening in the targeted skin area. Preferably, the particles in the reflecting substance should be between about 30 micrometer and about 80 micrometer.
c) Reflecting particles in suspension are rubbed into the skin so that the reflecting coating is covering the skin and sweat pore (or any other openings in the skin). Furthermore, the reflecting particles are forced into the hair follicle openings without completely blocking the hair follicle openings. d) Next, electromagnetic or other energy capable of being substantially reflected by the high reflective particles in the suspension is applied to the skin. The applied energy is reflected from most of the skin surface, but is trapped and propagated down the hair follicle by the reflecting substance in the hair follicle to
i) Remove the substance blocking the opening through the process of ablation, thus allowing enhanced pore drainage. Or, alternatively, ii) To thermally heat and destroy the blocking substance in the opening of the hair follicle thus allowing enhanced drainage. iii) To cause partial or complete destruction of the blocking component within the hair follicle and the hair follicle itself, thus allowing enhanced pore drainage or elimination of secretion from the treated follicles.
[0047] Since often hair growth is not desired in the areas effected by acne (for example, facial skin) elimination of hair growth might constitutes an additional benefit.
e) An alternative embodiment incorporating the use of highly precise interactions such as those generated by very short energy pulses may be particularly useful since such interactions are limited in space and may minimize any collateral damage in the area adjacent to the targeted opening of the hair follicles. In addition, localization of interaction may be enhanced due to “funneling” of incoming radiation due to coating of the walls of the hair follicle openings by the reflective coating. f) In another preferred embodiment, a short pulse of sufficiently high peak power is directed towards a targeted skin area with a high absorbing substance and a high reflectance substance confined to the hair follicle openings (for example, by one of the methods described above). Because of the high peak intensity and the localization of energy density by the reflective coating to the high absorbing substance, an explosive interaction will be initiated only in the opening of the hair follicle, physically opening the hair follicle to allow enhanced drainage.
[0050] FIGS. 1A, 1B and 1 C illustrate the principle of operation of the present invention as described herein and show a substance of high absorption and high thermal expansion being used. In this embodiment hair shafts are, if present, first removed from the surface of the skin to be treated for acne. They may be removed by either mechanical, or chemical means or by waxing.
[0051] As shown in FIG. 1A , the surface of the skin, 100 , is first covered by a substance 120 containing components characterized by a large optical absorption and high thermal expansion. These components in the applied substance may or may not be the same material. The substance 120 applied to the skin, may, for example, contain one, two, or more different types of material each serving a different purpose (one may yield significant thermal expansion while the other may yield a significant optical absorption).
[0052] The applied substance 120 is then rubbed and forced to penetrate the hair follicle opening 110 on the skin surface. Such a forceful skin penetration may also be accomplished by using an ultrasound or supersonic device to force the material farther into the skin pores. The particles within the applied substance 120 are designed to be too large to penetrate the sweat pores 105 , but small enough to penetrate the hair duct openings.
[0053] As shown in FIG. 1B , the substance applied to the skin is then scraped off by means of a rigid edge 200 or is simply wiped off the skin surface. This results in a relatively clean skin surface with an accumulation of the substance 120 of high absorption and high expansion substantially only in the hair ducts.
[0054] FIG. 1C shows a source of electromagnetic radiation 140 which is not absorbed by the skin but is well absorbed by the substance 120 . The result of radiation 140 being applied to the skin results in a rapid expansion of the substance 120 of high absorption and high expansion, in the direction shown by the arrows 180 . This expansion opens the hair ducts and allows drainage of the hair ducts. The heat generated thereby may also allow localized destruction of bacteria and cleaning and sterilization of the infected area in the hair duct. To minimize pain and control the spread of thermal energy a cooling agent 170 (for example, a cryogen spray or a cooled air flow) may also be applied a short time interval after the radiation is applied. Such localized heating and a more global cooling may enhance the expulsion of infected material out of the treated hair ducts.
[0055] Additional embodiments include:
A) Applying a substance consisting of a suspension of high thermal conductivity (HTC) to the area to be treated. Forcing said substance into the hair ducts. Forcing the HTC substance down the hair ducts, for example, by the use of an ultrasound field. The HTC substance particle should be large enough as to not enter sweat pores or any other opening in the skin other than the hair duct openings (about greater from 40 μm, but smaller than about 80 μm). Superficially wiping off the surface of the targeted surface but not removing it from the hair ducts. Applying a heat source or a laser to the skin surface being treated. The skin is an insulator, so substantially most of the HTC substance will heat up and open up the hair ducts to allow cleaning of the hair ducts. B) Applying a substance of high absorption to the surface of the skin. Forcing said substance down the hair ducts. The particles in said substance are such that they are not capable of penetrating into any other pores on the skin surface. Wiping the surface off substantially without removing said substance from the hair ducts. Applying electomagnetic radiation to the surface of the skin so that light is substantially absorbed mostly by the substance of high absorption in the hair ducts. Applying the light to selectively ablate or heat only the region of the opening of the hair ducts to allow drainage and cleaning action of the hair ducts. C) Applying a substance of high absorption to the skin and forcing said substance down the hair follicle. Wiping off excess substance on surface. Irradiating with a pulse duration such that no heat is transferred to adjacent tissue and causing rapid heating and expansion of the substance in the follicle openings. D) Applying a substance of high absorption to the skin and forcing said substance down the hair follicle. Wiping off excess substance on surface. Irradiating with a pulse duration such that no heat is transferred to adjacent tissue and rapid heating and expansion interaction occurs at follicle openings. E) Applying a substance of high absorption to the skin and forcing said substance down the hair follicle. Wiping off excess substance on surface. Irradiating with a pulse duration such that no heat is transferred to adjacent tissue and rapid heating, expansion and melting of “absorbing plug” occurs at follicle openings. F) Applying a substance of high reflection to the surface of the skin. Removing said substance from around the hair ducts. The particles in said reflective substance are such that they are not capable of penetrating (are too large) into any pores on the skin surface. G) Applying a substance of high absorption to the surface, forcing said substance down the hair ducts. Particles in said substance are such that they are not capable of penetrating into any other pores on the skin surface. Wiping skin surface off substantially removing said substance from the skin surface but not removing said substance of high absorption from hair duct openings.
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A method for treatment and modification of material including biological material using an electromagnetic energy source directed to apply the energy to a region of the material, so as to modify and treat a portion of the material in the region. Preferably, an interaction-modifying substance is in the treated region prior to the interaction.
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RELATED APPLICATIONS
The subject application is a continuation-in-part of U.S. Ser. No. 09/849,884, filed May 4, 2001, now abandoned, and claims the benefit of U.S. Provisional Application No. 60/220,173, filed Jul. 24, 2000, the contents of both of which are hereby incorporated by reference into the subject application.
General Embodiment 1
BACKGROUND OF THE INVENTION
Ultraviolet radiation is composed of three ranges, namely: UVA, which is from 320 to 400 nanometers, UVB which is from which is from 280 to 320 nanometers, and UVC which is from 100 to 280 nanometers. UVA and UVB are attenuated by the atmosphere, but is still reaches the earth's surface. UVC is usually blocked by the ozone in the atmosphere. Man-made lighting sources also produce ultraviolet radiation. Most fluorescent lighting has a high output in the UVA range. UVB causes more damage than UVA, but all ultraviolet radiation will cause degradation to materials.
Ultraviolet rays from the sun, or from man-made sources, degrade many materials by breaking their molecular bonds. Dyes and inks fade from ultraviolet, plastics lose their properties, paints chalk and fade, and many other items are damaged. Strategies to combat ultraviolet degradation include the use of materials that absorb ultraviolet radiation and convert it to heat energy. Most absorbers have an ultraviolet cutoff of 365 nanometers. A few have higher cutoffs, up to 384 nanometers with little to no yellowing. The phenomenon of producing a yellow cast when absorbers are used to block all of the ultraviolet radiation is due to the gradual slope of the absorption curve of the absorbing material. This slope, when the cutoff is extended to 400 nanometers, causes absorption of violet and blue light. The absence of blue light is perceived as yellow, and it is for this reason that most absorbers, especially in clear overcoatings, are not used to block all of the ultraviolet radiation up to 400 nm.
The optical density of a filter, an absorber, or a coating, to a range of radiation, is directly related to the concentration and thickness of the layer. The thinner the layer, the light the concentration of absorber is required. Very thin coating layers, below 10 microns cannot contain sufficient levels of absorption without a significant loss in the properties of the coating material. As an example, a 4 micron clear coating might require thirty percent, by weight, of an absorber to have complete absorption up to the cutoff wavelength of the absorber. Some common classes of ultraviolet absorbers are benzophenones and benzotriazoles.
A coating layer that is effective in blocking ultraviolet and is thin has the additional advantage of lower material cost and a higher degree of possible flexibility. A coating with a log concentration of absorber, so that the physical properties of the coating layer are not diminished, as well as the lower cost of using less absorber, that blocks all ultraviolet up to 400 nm, and does not have a significant effect on blue light absorption would a significant improvement in the effort to stop ultraviolet damage to materials.
SUMMARY OF THE INVENTION
The disclosed coating system blocks ultraviolet radiation up to and including 400 nanometers, the upper end of the ultra violet light. Preventing ultraviolet (uv) radiation from reaching materials and surfaces greatly improves weatherability and resistance to physical degradation from the effects of UV radiation on chemical bonds. There currently exist many types of ultra violet inhibitors, which are meant to be included in materials to improve their resistance to uv radiation. The damage from uv radiation is greater as the wave lengths of uv become shorter. However, considerable damage still occurs from the longer wavelengths of uv radiation. It is desirable to block the uv radiation and not have yellowing effect. The disclosed coating system remains water white.
DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS
In accordance with the invention, the disclosed coating system is a two-layered system using a typical ultraviolet absorber in its inner layer (called the blocking layer), furthest away from the source of ultraviolet exposure, with a fluorescent material with reflects ultraviolet radiation back as blue light. The ultraviolet absorber in the inner layer is used in sufficient concentration to have an ultraviolet cutoff, which can be extended with the fluorescent material. There are natural fluorescent materials such as calcite, will mite, sprite, fluorite, and diamonds. Three are also man-made fluorescent materials used to make materials look whiter by reflecting the long wave ultraviolet radiation as blue light. These are called optical brighteners. Typical optical brighteners are disulphonates, tetrasulphonates, and hexasulphonates. These are water soluble optical brighteners. An example of a solvent soluble optical brightener is Uvitex OB from Ciba-Geigy Corp. Such optical brighteners are typically used in textiles at very low concentrations of less than one percent by weight. Their purpose is to reduce the yellowness of a material, dye, plastic, etc. The present invention provides the desired protection by combining an optical brightener with an ultraviolet radiation absorber which raises the cutoff wavelength and increases blue light, rather than absorbing blue light as a longer wavelength cutoff ultraviolet absorber would normally do.
This barrier require high levels of optical brightener to convert the longer wavelength ultraviolet radiation into blue light and do this effectively enough to block the transmission from outer layer to the inner layer due to the total conversion of longer wavelength ultraviolet to blue light. The high level of optical brightener causes a significant fluorescent effect upon exposure to ultraviolet radiation, where this layer will glow with blue light.
The Surface of the inner or blocking layer also has a significant quantity of fluorescent material, which is not protected in depth by the included ultraviolet absorber. This is the primary reason the second or outer coating layer is effective in reducing fluorescence and why it is necessary. The fluorescent material in the inner layer that lies in the matrix of resin and ultraviolet absorber is then protected from excessive fluorescent excitation. Another technique is to use an alkaline material in the outer coating to decompose the surface of the optical brightener of the blocking layer. Still another technique to reduce surface fluorescence is to use an optical brightener quencher such as OBA Quencher from Kalamazoo Paper Chemicals Corp.
While a single blocking layer can be used for protection against ultraviolet, the fluorescent blue glow is generally undesirable. In order to significantly reduce this fluorescence, it is necessary to reduce the amount of ultraviolet that reduces this layer in the peak wavelengths for fluorescence. This is done by applying an overcoating to the blocking layer, which contains some level of ultraviolet absorber that reduces the ultraviolet transmission of the wavelengths that cause fluorescence. It is then this combined effect and balance, which completely blocks ultraviolet radiation without yellowing.
The outer coating can provide other properties such as chemical resistance, scratch resistance, slip, or friction. The outer coating material can be any resin system with an ultraviolet inhibitor, but it is preferable clear and relatively ultraviolet transparent. Materials that do not absorb ultraviolet on their own are relatively unaffected by exposure to it. For this reason, typical clear outer coating resins would be aliphatic urethanes, polysiloxanes or acrylics.
Fluorescent materials have been used in may applications to “whiten” whites, or brighten colors in may products. The teclunique is to use the fluorescent material to increase the reflected blue light. The increase in blue light is perceived as a reduction in yellow light form the fluorescent material. It typically takes very small quantities of fluorescent material to accomplish this brightening effect.
UV absorbers are widely available and are commonly used with intention of blocking primarily UVB. When these uv absorbers are used to block all uv light, they increase yellow light perception due to the reduction in blue light.
Higher concentrations of fluorescent materials in a single layer coating will cause a blue fluorescent glow to the material when it is exposed to uv light. This is cosmetically objectionable. For this reason, only low concentrations are used for brightening.
Blocking uv from reaching the surface of an object is a function of film thickness and concentration. Thin films down to 3-5 microns would require very high concentrations of uv absorbers to have complete blocking power. These thin films, such as those in polysiloxane abrasion resistant coatings, would need uv absorber concentrations as high as 30 percent to accomplish an optimal absorption based on the uv absorber. At that concentration, the properties of the coating are drastically degraded.
The inside layer of the present system can be in a range of 6 microns or higher, using Uvitex OB (Ciba-Geigy), with 9-15 microns being optimum. This range is based on the maximum solubility of the uv absorber and the fluorescent material. If other uv absorbers and fluorescent materials are chosen, this film thickness range can be adjusted accordingly.
The second or outer coat, in order to maintain flexibility, must be in the 3 micron-3 mil range film thickness depending on the brittleness of the resin system. In order to maintain the properties of the outer coat at this film thickness, it is necessary to keep the uv absorber in this layer at the maximum level before degradation of the physical properties of the coating occurs.
In accordance with the invention, the disclosed system includes an outer coating which also has a uv absorber to prevent the blue glow at the inner surface of an inner layer. This blue glow will appear hazy prior to application of the outer coating.
UVA absorbers that block all uv up to 400 nm tend to be significantly yellow in color. This is because of their absorption curve. The more gradual the slope of the curve the more visible blue and violet light is absorbed which is then perceived as yellow. It is desirable when blocking uv up to 400 nm to have a very steep transmission curve with a transmission cutoff at 400 nm to avoid the yellowing effect.
Degradation due to outdoor exposure also occurs from pollutants, which are carried to the item via precipitation and air. These pollutants are typically oxides and various dilute acids such as acid rain. The pollutants can cause colorants to fade, as the molecular bonds are broken. It is desirable to have protection against this type of chemical breakdown such as a chemically resistant barrier.
Certain items, such as printed paper, can also be damaged by precipitation such as rain and snow, which, in the form of water, causes the paper to deteriorate and some print materials such as ink to bleed. It is therefore desirable to create a barrier to precipitation for good outdoor weatherability.
There currently exist coatings and laminations, which are partial uv blockers and which are transparent but have poor abrasion resistance, such as vinyl coatings and laminates. It is desirable to have good abrasion resistance in a product to be used outdoors to prevent changes in gloss levels from abrasion which might be caused by windbome debris or cleaning.
The current practice of including uv absorbers in the body of plastic items or in overcoatings is often of limited effectiveness because it is weakened by the relationship of film thickness and concentration of uv absorber. The thicker the coating the lower the concentration of uv blocker necessary. Thin coatings are often desirable due to cost and flexibility. When a uv absorber is included in a colored molded item, the surface has the lowest concentration of uv absorber and so this surface degrades quicker than the material behind this surface. Thus, even though the colored material contains uv absorber, its relative concentration at the surface of the item is low, so the color fades at the surface. With suitable coating, the weatherability of a molded plastic item is improved in terms of physical properties except for a significant improvement in color fade, as this is a surface effect. The bulk of the material has protection in depth.
The best combination of protection against color fade is to include pigments, which are resistant to uv degradation along with uv inhibitors. In the inkjet industry it is common to combine uv resistant inks with an uv inhibiting outer laminate for further Protection against fading in applications where long term exposure to uv is expected.
Solvent selection requires compatibility with the resin systems and additives, leveling characteristics, and the prevention of crystallization of the additives. The following examples are illustrative.
EXAMPLE 1-1
The following example achieves a 9-10 micron film thickness. Percentages are by weight of volume solids.
Inner Coating
Acryloid A 21 - (Rohm & Haas)
25%
Uvitex OB - (Ciba-Geigy Corp.)
11%
based on solids
Tinuvin 328 - (Ciba-Geigy Corp.)
8%
based on solids
Acetylacetone
8%
based on total weight
Diluent toluene or xylene - depending upon method of application.
Outer Coating
A second coating is used to achieve a
3-4 micron film thickness. It comprises:
GR 653 polysiloxane coating -
25%
solids
(Techneglas)
97.5
parts
Tinuvin 328 - (Ciba-Geigy Corp.)
1.5
parts
Toluene -
1
part
EXAMPLE 1-2
Inside Layer - Urethane
Desmodur N-75: Bayer
36%
of urethane solids
Desmophen 670A-80: Bayer
64%
of urethane solids
Catalyst, dibutyltindilaurate:
0.1%
based on urethane solids
UV inhibitor, Tinuvin 328 -
8%
based on urethane solids
(Ciba-Geigy)
Fluorescent, Tinuvin OB - (Ciba-Geigy)
11%
based on urethane solids
Surfactant, Flurad 430 - (3M)
0.1%
based on urethane solids
Diluent, Toluene
To make 100%
The best order for mixing is to determine the amount of toluene that will be the diluent and stir in the Tinuvin OB until it completely dissolves. Add the uv inhibitor and stir until completely dissolved. Add the Desmophen 670-80A and stir until completely dissolved. Add the dibutyltindilaurate and stir. Add the catalyst and stir gently, until it is completely dissolved. The solids level of this coating can be adjusted to the processing technique and conditions to achieve approximately 15 microns film thickness. The lower the film thickness, the higher the required level of Tinuvin 328 and Tinuvin OB. The ratio between uv inhibitor and fluorescent material is dependent on the uv absorption of the inhibitor and the wavelength shift of the fluorescent material. The goal is to make the uv cut-off up to 400 nm and then have maximum light transmission for the visible spectrum.
Outer Layer - Acrylic
Acryloid A-21 - (Rohm & Haas)
received at 30% solids, diluted
to 25% solids with toluene
Flurad 430 (3M)
0.1%
based on total coating solids
Tinuvin 328 - (Ciba-Geigy)
8%
based on A-21 solids
Tinuvin OB - (Ciba-Geigy)
11%
based on A-21 solids
Acetylacetone
8%
of total weight
EXAMPLE 1-3
Polysiloxane Outer Layer
SHC 4000 (General Electric)
98.4%
Tinuvin-328 (Ciba-Geigy)
1.5%
Triethanolamine (optical
0.01%
brightener)
Toluene or xylene solvent to achieve desired film thickness.
Acrylic Inner Layer
Joncryl 537 - (Johnson's Wax)
Aqueous acrylic dispersion
Uvinul D40 - (BASF-Wyandotte)
8%
based on resin solids
Flurad 430 - (3M)
0.1%
based on resin solids
Triethanolamine
0.1%
based on resin solids
OBA Quencher -
0.1%
based on resin solids
(Kalamazoo Chemical Corp.)
The outer coatings provide desired physical properties and they provide quenching of the optical brightener at the surface of the inside coating. This quenching is accomplished by uv transmission reduction by the outer coating an/or by adding a higher pH material, such as minor amounts of tetramethylaminohydroxine to the outer coating which quenches the optical brightener.
Some typical applications are store front display windows to protect the items on display from ultraviolet damage, protection of inkjet prints which are very susceptible to ultraviolet degradation plastic sheeting which degrades and turns yellow in outdoor applications, works of art which are subject to man-made ultraviolet radiation, and, in general, any item that is damaged by ultraviolet radiation. In order to achieve weatherability of inkjet prints which may be used for signs, posters, billboards, etc., it is often necessary to laminate them with films that provide protection against ultraviolet radiation.
In another embodiment, a thin layer of polyester film is coated on one surface with the blocking layer and the second coating is applied to the opposite surface. The film is provided with a suitable laminating adhesive, such as heat-activated vinyl, EVA, and similar adhesives. The film may be applied to an inkjet print on the printed side. This embodiment of the coating systems forms a thin flexible transparent tear resistant laminate which blocks out ultraviolet to less than one percent transmission at 400 nm and to less than 0.1% transmission below 400 nm down to 280 nm. A polysiloxane coating also provides scratch resistance, as well as chemical resistance.
By providing a two-layer system, rather than a single layer system, It is possible to have the inner layer absorb the bulk of received ultraviolet radiation, and reflect radiation above 375 nm as blue light, so that the coating is seen as clear rather than as a yellow tint. Most conveniently, both layers are applied using known spraying techniques in serial fashion, which lends itself to the application of both layers upon a thin polyester film, and the like. Other methods are possible, including dipping, flow-coating, curtain coating or by any other liquid application method. I wish it to be understood that I do not consider the invention to be limited to the precise detains and examples described hereinabove, for obvious modifications will occur to those skilled in the art to which the invention pertains.
General Embodiment 2
BACKGROUND OF THE INVENTION
This invention relates generally to the field of light blocking or light absorbing filters, and more particularly to an improved filter material suitable for blocking harmful ultraviolet rays from artificial light transmitting sources.
It is known in the art to provide ultraviolet light blocking filters which are in the form of coatable fluids, or laminated sheets of clear synthetic resinous materials which are applied directly to an article to be protected to improve the resistance fading and other deterioration caused by exposure to daylight, and in particular, sunlight. Radiation in the ultraviolet spectrum and particularly that in the range of 365 nm and 400 nm is particularly destructive. However, most widely used filtering materials are effective up to about 365 nm, but are of drastically reduced effectiveness above that value.
Many valuable, indeed, irreplaceable objects are exhibited in museums, which for the most part are illuminated by artificial light of both fluorescent and incandescent types. For the most part, such lighting does not provide a serious problem. Such museums are, however, visited by millions of viewers each year, many of whom take their own photographs using electronic flash units which transmit light of a quality having sufficient ultraviolet wave lengths including the above mentioned upper range. While a single exposure produces negligible amounts of ultraviolet light, where even a small fraction of the visitors photograph the same objects, the cumulative effect of such exposure is substantial. As a result, many museums, forbid the taking of photographs by visitors altogether.
Because electronic flash illumination is normally transmitted through a focusing lens, it has not been heretofore possible to filter this light as a practical matter.
SUMMARY OF THE INVENTION
Briefly stated, the invention contemplates the provision of a novel ultraviolet filter material capable of full ultraviolet wave blockage in coatable fluid form which may be readily permanently adhered to transparent glass or plastic surfaces, and which will not interfere with the transmission of visible and photoactinic energy. This material is applied preferably to the inner surfaces of electronic photo flash lamps or focusing lens therefor, and may also be used in the manufacture of any light source in which the elimination of ultraviolet light is desirable. Most suitably, the composition is applied in thickness ranging from five to ten microns using standard application techniques, such as flow coating, spray coating, dipping, curtain coating and the like. It may also be used with coating thicknesses of as little as 2 microns, with the use of certain precautions.
It is a principal object of the present invention to provide a coating which can be applied to the lens or envelope of a light source, or a window which is transmitting light, that will be waterwhite, and efficiently block ultraviolet emission employing coating thickness of less than 50 microns, typically less than 10 microns. It is also an object of this invention to block ultraviolet transmission from light sources which typically also emit heat. This aspect is important with regard to any resin system thermally degrading and yellowing or cracking.
Sources or lenses covering light sources can be coated with resin systems that are themselves, for the most part, transparent to ultraviolet transmission, and so unaffected by it, and that contain ultraviolet inhibitors or other ultraviolet reducing materials such as fluorescent materials which will efficiently block ultraviolet transmission. These coatings can be applied to laminating films which can be applied to flat surfaces, or to laminating films which can be thermal formed over curved surfaces.
Certain of the disclosed embodiments are not only capable of blocking ultraviolet light, but actually converting at least a portion of the ultraviolet light to visible light, thus increasing the efficiency of light transmission which is particularly useful when the covering is applied to an incandescent or fluorescent light source. This effect is obtained by the incorporation of a fluorescent material in larger quantity as compared to the material used for ultraviolet absorption.
DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS
There are several commonly available systems that are essentially ultraviolet transparent and therefore unaffected by ultraviolet exposure. These include acrylics, urethanes, polysiloxanes, and to a lesser degree, phenoxy resins.
The two main classes of ultraviolet inhibitors are benzotriazoles and benzophenones. The benzophenone class tends to be very yellow when used in concentrations that efficiently block ultraviolet transmission. The benzotriazoles typically block ultraviolet transmission up to 365 nm and a few of them will block ultraviolet radiation up to 380 nm.
Including a fluorescent material that converts long wavelength ultraviolet into longer wavelength blue light will increase the ultraviolet blocking efficiency up to 400 nm. The inclusion of fluorescent material may not be necessary if the light source is a man-made light source which does not emit the longer wavelengths of ultraviolet light.
The phenoxy resin systems can be cross-linked with typical cross linkers for hydroxy-functional resins, such as melamine, urea-formaldehyde, heat reactive phenolica, and isocyanate-flnctional prepolymers.
Dipping, spraying, flow coating, curtain coating, or any other liquid coating application technique can apply these coatings. The following examples are illustrated. Proportions are by weight of resin solids.
EXAMPLE 2-1
Glass and plastic surfaces
1.
Phenoxy resin, 20% (Paphen PKHC, Phenoxy Specialties,
Rock Hill, South Carolina)
2.
Melamine Crosslinker (Cymel 325, Cytec Industries,
1.6%
Inc., W. Paterson, New Jersey)
3.
Tinuvin-328 (Ciba-Geigy)
6%
4.
Uvitex OB (Ciba-Geigy)
2.5%
5.
Surfactant (Flurad 43, 3M Co.)
0.001%
6.
Dioxolane Diluent to 100%
To improve adhesion to glass surfaces requires heating to 350 F. for ten minutes or longer times at lower temperatures. In some cases, the heat of an incandescent light source will be sufficient to fully crosslink this coating.
EXAMPLE 2-2
Using acrylic solids, the following formulation is suitable; proportions are by volume of resin solids.
1.
Acrylic resin (Acryloid A 10 S Rohm & Haas)
20%
2.
Tinuvin-328 (Ciba-Geigy)
6%
3.
Uvitex OB (Ciba-Geigy)
2.5%
4.
Surfactant (Flurad 430, 3M Co.)
0.001%
5.
Toluene or dioxolane diluent to 100%
To improve adhesion to glass surfaces, it may be necessary to pretreat the glass surface by etching or treating it with a hydrolyzed amino silane coupling agent, or to other commonly known techniques to provide good adhesion to glass.
The Uvitex OB may be omitted if complete ultraviolet absorption is not required. Using the Tinuvin 328 alone at the described concentration to resin solids will produce an ultraviolet cut-off at 380-384 nm at a 9-micron film thickness.
These coatings may be further protected by overcoatings for additional chemical resistance or abrasion resistance. Some examples are aliphatic urethanes and polysiloxanes.
The described embodiments relate to a thin coating that can be applied to either the inside surface of, or the outside surface of light sources or display window. As discussed above, ultraviolet light is the primary cause of photo degradation of may exposed items. It is the primary cause of colors fading, paints chalking, paintings cracking, fabrics fading, and the loss of physical properties such as tensile and impact strength of many materials. Ultraviolet is defined as light having a wavelength of 400 nm or less.
The current technology reduces the photodegradation effect of ultraviolet light by including ultraviolet inhibitors in the body of materials to be protected or by overcoating the products with ultraviolet resin systems. Most ultraviolet inhibitors block or absorb ultraviolet radiation up to 380 nm in coatings that are at least one nm thick. Thinner films usually absorb considerably less ultraviolet not only in optical density, which is the percentage absorbed, but also not as high at 380 nm. The most common absorption cut off is 360 nm.
Articles formed from materials that have ultraviolet inhibitors included still have photodegradation at the surface. Absorption efficiency is determined by the absorption characteristics of the inhibitor and is directly related to concentration and thickness. The thinner the film, the higher the required percentage of ultraviolet absorption material required. For example, a 9 micron film may require 30% based on resin solids for efficient blocking. Most ultraviolet inhibitors will impair transparency when included in clear coatings at that level or they will degrade the physical properties of the coating resin system.
An example of an application is light sources in museums. Museums are very cautious about picture taking and light source relative to artwork or artifacts. All incandescent light sources emit ultraviolet radiation, as do all fluorescent light sources. Coating the surface of the emitting source with a total ultraviolet blocking coating protects all items exposed to that source. Electronic flashes are normally provided with a focusing lens which can be coated to completely block ultraviolet thus making them safe in museum and art galleries. Preferably, this coating is done on the inner surface of such lenses.
EXAMPLE 2-3
A Melamine Crosslinked Flexible Resin System
Proportions are by volume of resin solids.
1. Paphen phenoxy resin PKHC range 10%-40% (Phenoxy Specialties, Rock Hill, S.C.)
2. Cymel 303 melamine resin—range 2%-10% (Cytec Industries, Long Beach, N.Y.)
3. P-toluene sulfuric acid catalyst—range 0.001-%-0.1%
4. Uvitex OB—range 1%-6% (Ciba-Geigy) Optical brightener
5. Tinuvin 328—range 0.2%-4% (Ciba-Geigy) U.V. absorber
6. Solvents for dilution to create the desired film thickness, including methyl ethyl ketone, dioxolane, toluene and others to make 100%.
The above formulation has excellent tensile strength. These properties are of particular value when the coating is applied to a glass light bulb. The coated bulb will tend to be held together when the bulb is broken, for improved safety.
EXAMPLE 2-4
A Melamine Resin System
Cymel 303 solids—range 20%-50% (Cytec Industries)
P-toluene sulfuic acid catalyst—range 0.01%-0.3%
Uvitex OB—range 1%-8% (Ciba-Geigy)
Tinuvin 328—range 0.1%-4% (Ciba-Geigy)
Solvents for dilution to achieve film thickness, including toluene, xylene, methyl ethyl ketone, dioxolane and others to make 100%.
Either sample will cure at temperatures of 250 F. -350 F., with shorter times for higher temperatures.
The primary material that blocks most of the ultraviolet light and converts it to visible light is the Uvitex OB in sufficient quantities ranging from 0.1% to as much as 8%. As indicated by the following graph, this light appears as visible light in the range of 420 nm to 575 nm, with peaks at 440 nm and 490 nm. This result was obtained by coating a standard 20 watt fluorescent tube to 9 nm thickness. It has been determined that in the case of incandescent and fluorescent lamps, the covered ultraviolet light may range to as much as 30 percent to 50 percent of the total light output.
Absorption of ultraviolet radiation up to 380 nm employs a standard ultraviolet absorber. Absorbing up to 380 nm is not a requirement. It may be less than 340 nm provided that the fluorescent material makes up the difference. The fluorescent material converts ultraviolet radiation from about 340 to 400 nm to visible light. This provides a complete ultraviolet cutoff with almost any commercially available ultraviolet absorber combined with a fluorescent material.
If intense ultraviolet radiation reaches the disclosed blocking system, it may cause a glow from the fluorescent material. However, two steps can prevent the glow using a two-layer coating system, and using a slower drying solvent such as acetylacetone, or similar solvents such as xylene. A requirement is that the solvent dry slowly, and must be compatible with the resin system, the ultraviolet absorber, and the fluorescent material.
This can also be accomplished in a single solvent system as thin as 2 microns. The lower film thickness is provided by increasing the percentage of ultraviolet blocking materials to 40 percent based on resin solids. This is useful, for example, in dye transfer sublimation, where low film thicknesses are absolutely necessary to transfer the coating from a film to the surface of an image.
EXAMPLE 2-5
A 2 Micron Example
1.
Acryloid A21 (Rohm & Haas) at 7% solids
22.94%
2.
Tinuvin 328 (Ciba-Geigy)
1.18%
3.
Uvitex OB (Ciba-Geigy)
1.62%
4.
FSN 100 (Zonyl surfactant, Dupont)
0.1%
5.
Acetylacetone
8%
6.
Toluene
37.05%
7.
Methyl isobutyl ketone, or methyl ethyl ketone
37.05%
If the film thickness is increased to 9 microns, the level of ultraviolet blocking materials is decrease to 19 percent based on resin solids.
High temperature resin systems can be used with the disclosed system for application to high temperature light sources. Another embodiment is to provide a hybrid lightbulb, one that is coated with a fluorescent material on its outside surface to convert the ultraviolet emission of the bulb in to visible light. No ultraviolet absorber is necessary unless it is necessary to remove the ultraviolet radiation below 340 nm. The object of this embodiment is to increase visible light by converting ultraviolet light into visible light. A side effect is that the conversion also blocks the ultraviolet from about 340 nm and higher. If it is also necessary to block lower ultraviolet wavelengths, then an ultraviolet absorber must be used with the fluorescent material.
Each of these coatings uses a binder resin. The properties of the binder resin allow these coatings to be use din different applications. For example, the bulb coating can be made with a fluorescent material and a high temperature resin such as GR 150 or GR 908 (polysiloxane resin, from Techneglas). These resins can withstand very high temperatures for extended periods of time. These resins can also be used on high intensity halogen bulbs, which have a very high ultraviolet emission. For low temperature applications, such as a fluorescent bulb, acrylic resin can be used. IN such applications, it is not a requirement to use an ultraviolet absorber in the lightbulb coating, merely a fluorescent material.
The concentration of fluorescent material is optimized in the following example:
EXAMPLE 2-6
A Bulb Coating Formulation
GR 150 (Techneglas, Long Beach, N.Y.) at 15% solids
MIBK/Toluene 50150% we weight
Acetylacetone 8% of total weight
Uvitex OB 19% based upon GR 150 solids
BYK 330 (BYK Chemie, Middletown, Conn.) 0.5% based on resin solids
EXAMPLE 2-7
Using the proportions of Example 6, GR 150 is substituted by G.R. 908 (Techneglas).
It will be appreciated that a variety of ultraviolet absorbing materials may be used in conjunction with an optical brightener which will be operative to cover the range commencing t the wavelength where the ultraviolet absorber ceases to operate, to provide a substantially complete cutoff.
the relative output of a coating versus an uncoated 20 watt fluorescent tube. In the case of the uncoated lamp, radiation commences at about 330 nm, with the bulk of the light put output extending between that point and 425 μm. There are peak outputs at 440 nm, 550 nm, and 575 nm.
By contrast, the coated lamp has substantially all radiation up to about 415 nm completely blocked, with the visible output commencing at about 420 nm and extending 30 to about 570 nm. It will be observed that there is an area commencing at 425 nm where the curve crosses and extends above that for the uncoated lamp to about 570 run, indicating that a portion of the ultraviolet light has been converted to the visible light spectrum.
I wish it to be understood that I do not consider the invention to be limited to the precise details disclosed in the specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.
General Embodiment 3
SUMMARY OF THE INVENTION
The ultraviolet block material of the present invention, has transmittance of the light within a range of wavelength of 300-380 nm of 10% or less, preferably transmittance of the light within a range of wavelength of 300-390 nm of 10% or less and, particularly preferably, transmittance of the light within a range of 300-400 nm of 10% or less while it has a transmittance of the light within a range of 420-800 nm wavelength of 90% or more or, preferably, 95% or more.
Especially when the transmittance of ultraviolet light within a range of 350-380 nm wavelength, preferably 350-390 nm or, particularly preferably, 350-400 nm wavelength is too high, such ultraviolet light decomposes the colorant whereby it is not possible to effectively prevent color fading, discoloration and decolorization.
When the transmittance of light within a range of 420-800 nm is too low, the ultraviolet block material is colored or the transparency thereof is lowered disadvantageously.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is light transmittance spectra of Examples 1-4 and Comparative Examples 1 and 2; FIG. 2 is an example of the ultraviolet block material of the present invention; FIG. 3 is an example of a method for the protection of a material to be layered, using the ultraviolet block material of the present invention; and FIG. 4 is an example where the ultraviolet block layer of the present invention is provided on a color sheet which is used for a thermal transfer printing or the like.
In the drawings, 1 is an ultraviolet block material; 2 is a substrate: 3 is an ultraviolet block layer; 4 is a layer containing a fluorescent material; 5 is a layer existing between the substrate and the layer containing a fluorescent material; 6 is a layer existing at the side, opposite to the substrate, of the layer containing the fluorescent material; 7 is an adhesive layer; 8 is a material to be layered; 9 is a side of a material to be layered where the image is formed; 10 is a color sheet; Y is a color material layer containing a yellow colorant; M is a color material layer containing a magenta colorant; C is a color material layer containing a cyan colorant; and OC is an ultraviolet block layer of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The ultraviolet block material of the present invention usually contains an ultraviolet radiation absorber and a fluorescent material.
Ultraviolet Radiation Absorber
With regard to an ultraviolet radiation absorber, that which mainly absorbs the light within a range of 300-380 nm may be exemplified and that of a benzophenone type, a benzotriazole type, a salicylic acid type and a hydroquinone type can be used. Preferably, a benzophenone type and a benzotriazole type are used and, particularly preferably, a benzotriazole type is used.
Examples of a benzophenone type are 2-hydroxy-4-n-octoxybenzophenone such as CHIMASSORB 81 FL (a product of Ciba-Geigy); 2-hydroxy-4-methoxy-2′-carboxybenzophenone; 2,4-dihydroxybenzophenone; 2,2′-dihydroxy-4,4′-dimethoxy-benzophenone such as Uvinul D-49 (a product of BASF); 2-hydroxy-4-benzoyloxybenzophenone; 2,2′-dihydroxy-4-methoxy-benzophenone such as Cyasorb UV-24 (a product of ACC); 2-hydroxy-4-methoxy-5-sulfonebenzophenone; 2,2′,4,4′-tetrahydroxybenzophenone; 2,2′-dihydroxy-4,4′-dimethoxy-5-sodium sulfonebenzophenone; 4-dodecyloxy-2-hydroxy-benzophenone; and 2-hydroxy-5-chlorobenzophenone and the like.
Examples of a benzotriazole type are 2-(5′-methyl-2′-hydroxyphenyl)benzotriazole such as Tinuvin P (a product of Ciba-Geigy); 2-(2′-hydroxy-5′-tert-butylphenyl)-benzotriazole such as Tinuvin PS (a product of Ciba-Geigy); 2-[2′-hydroxy-3′,5′-bis(α,α-dimethylbenzyl)-phenyl]-2H-benzotriazole such as Tinuvin 234 (a product of Ciba-Geigy); 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-benzotriazole such as Tinuvin 320 (a product of Ciba-Geigy); 2-(3′-tert-butyl-5′-methyl-2′-hydroxyphenyl)-5-chlorobenzotriazole such as Tinuvin 326 (a product of Ciba-Geigy); 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole such as Tinuvin 327 (a product of Ciba-Geigy); 2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)-triazole such as Tinuvin 328 (a product of Ciba-Geigy); 5-tert-butyl-3-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxybenzenepropionic acid octyl ester such as Tinuvin 109 (a product of Ciba-Geigy); and 2-(2′-hydroxy-3,5-di-(1,1′-dimethylbenzyl)phenyl)-2H-benzotriazole such as Tinuvin 900 (a product of Ciba-Geigy) and the like.
Examples of a salicylic acid type are phenyl salicylate such as Seesorb 201 (a product of Shiraishi Calcium); p-tert-butyl salicylate such as Sumisorb 90 (a product of Sumitomo Chemical); and p-octylphenyl salicylate (a product of Eastman Chemical) and the like. Examples of a hydroquinone type are hydroquinone and hydroquinone salicylate and the like.
Amount of the ultraviolet radiation absorber used for the base material is usually not less than 5% by weight, preferably not less than 6% by weight or, more preferably not less than 10% by weight and usually not more than 30% by weight or, preferably, not more than 25% by weight. When the amount of the ultraviolet radiation absorber is too small, it is not possible to make the light transmittance of ultraviolet region 10% or less while, when it is too much, there is a possibility that the ultraviolet radiation absorber bleeds out.
Fluorescent Material
A fluorescent material is that which absorbs ultraviolet light of a wavelength region of 340-400 nm and emits the light within a range of 400-500 mn. A fluorescent material absorbs the long-wave region of ultraviolet light and, therefore, fading, discoloration and decolorization of the colorant can be effectively prevented when a fluorescent material is contained.
Examples of a fluorescent material are materials of a diaminostilbene type, an imidazole type, a thiazole type, an oxazole type (such as 2,5-bis[5-tert-butylbenzoxazol-2-yl]thiophene [Uvitex OB, a product of Ciba-Geigy]), a triazole type, an oxadiazole type, a thiadiazole type, a coumarin type, a naphthalimide type, a pyrazoline type, a pyrene type, an imidazolone type, a benzidine type, a diaminocarbazole type, an oxacyanine type, a methine type, a pyridine type, an anthrapyridazine type, a distyryl type and a carbostyryl type and the like. Preferably, an oxazole type is used.
Amount of the fluorescent material contained for the base material is usually not less than 3% by weight, preferably not less than 6% by weight or, more preferably, not less than 10% and usually not more than 30% by weight or, preferably, not more than 25% by weight. When the amount of the fluorescent material is too small, it is not possible to make the light transmittance of ultraviolet region of not shorter than 380 nm 10% or less while, when it is too much, there is a possibility that the fluorescent material bleeds out.
Examples of the base material constituting the ultraviolet block material are synthetic resin, oil, gelatin and starch, which are not colored at the visible light region, and, usually, resin is used. Any resin may be used so far as it can be made into film or can form a resin layer as a result of drying and/or hardening when applied on a substrate. To be more specific, polyester resin, polystyrene resin, acrylate resin, polyurethane resin, acrylurethane resin, vinyl chloride resin, polyamide resin, vinyl acetate resin, epoxy resin, phenoxy resin, and cellulose type resin may be exemplified.
Overcoat
As shown in FIG. 2, an embodiment of the ultraviolet block material of the present invention is in such a structure having a substrate 2 and an ultraviolet block layer 3 which is provided on the substrate in a releasable manner.
Such an ultraviolet block material 1 can be adhered on a material 8 to be transferred by, for example, the following manner.
First, as shown in FIG. 3 ( a ), the farthest side of the ultraviolet block layer 3 of the ultraviolet block material 1 from the substrate is layered on a material 8 to be attached. The farthest side of the ultraviolet block material from the transcription layer usually has an adhesive layer 7 for making the adhesion with the material to be transferred better. When an image is formed on the surface of the material to be transferred, the side 9 on which the image is formed is piled on the ultraviolet block material so as to contact the farthest side from the substrate of the ultraviolet block layer thereof.
After that, the ultraviolet block layer and the material to be transferred are adhered by means of heating or pressurization.
Finally, as shown in FIG. 3 ( b ), the substrate 2 is separated from the ultraviolet block layer 3 whereby only ultraviolet block layer 3 is adhered on the material 7 to be transferred. A method where only an ultraviolet block layer is layered on the material to be transferred as such is called overcoat.
In an ultraviolet block material comprising a substrate and an ultraviolet block layer provided on the substrate in a releasable manner, the layer which is farthest from the substrate of the ultraviolet block layer may be a layer for receiving color materials. When the layer which is farthest from the substrate of the ultraviolet block layer is a color material-receiving layer, it is possible that image is formed on the color material-receiving layer of the ultraviolet block material of the present invention by means of an ink jet printing method, a thermal transfer printing method or the like, then the color material-receiving layer and the substrate paper are layered so as to be contacted, the ultraviolet block layer and the substrate paper are stuck, then the ultraviolet block layer and the substrate paper are adhered by means of heating or pressurization and the substrate is separated from the ultraviolet block layer whereupon a protected image can be formed.
Overcoat: 1
One of the preferred embodiments in an ultraviolet block material comprising a substrate and an ultraviolet block layer provided on the substrate in a releasable manner is a structure in which the ultraviolet block layer has a layer containing a fluorescent material, the layer containing the fluorescent layer has at least one layer between it and the substrate and there is also at least one layer on the layer containing the fluorescent material at its side opposite to the substrate and, in addition, any of the layers contains an ultraviolet radiation absorber.
As a result of having such a structure, the layer containing a fluorescent material does not directly contact the air even in a state where the ultraviolet block layer is present on the substrate or even in a state where the ultraviolet block layer is layered on the material to be transferred and, therefore, reduction in the ultraviolet blocking ability can be significantly suppressed. When the layer containing the fluorescent material contacts the air, the fluorescent material is decomposed by light and oxygen in air whereby the ultraviolet blocking ability lowers immediately and the ultraviolet block material allows the transmittance of ultraviolet light of near 350-380 nm wavelength.
When at least one layer among the layers between the substrate and the layers containing a fluorescent material contains an ultraviolet radiation absorber, the outcome is that the ultraviolet radiation absorber is present outside of the layer containing the fluorescent material under such a state that the ultraviolet block layer is adhered on the material to be transferred. Accordingly, especially in case the material to be transferred is an image, ultraviolet light at first passes through the layer containing the ultraviolet radiation absorber and then arrives the layer containing the fluorescent material whereby the amount of the ultraviolet light arriving the layer containing the fluorescent material can be reduced and the decomposition of the fluorescent material by ultraviolet light can be effectively prevented.
Preferably, the layer containing the fluorescent material contains an ultraviolet radiation ab sorber. When the layer containing the fluorescent material contains an ultraviolet radiation absorber, that is preferred in such a respect that the amount of ultraviolet light affecting the fluorescent material can be reduced as same as in the above-mentioned case.
Particularly preferred one is a structure where an ultraviolet radiation absorber is contained in a layer containing the fluorescent material and also at least in one layer among the layer existing between the substrate and the layer containing the fluorescent layer. Such a structure is preferred in such a respect that the ultraviolet light affecting the fluorescent material can be further reduced.
Overcoat: 2
Another preferred embodiment in an ultraviolet block material comprising a substrate and an ultraviolet block layer provided on the substrate in a releasable manner is that the ultraviolet block layer comprises a layer containing a fluorescent material and that the layer containing the fluorescent material contains an ultraviolet radiation absorber and a stabilizer.
In such a structure, the stabilizer is present in a layer containing the fluorescent material and, therefore, decomposition of the fluorescent material by ultraviolet light and by oxygen can be effectively suppressed.
It is preferred in the above structure that the structure has at least one layer between a substrate and a layer containing the fluorescent material or that the structure has at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material.
Particularly preferred structure is that there is at least one layer between the substrate and the layer containing the fluorescent material and further that there is at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material.
In case where there is at least one layer between the substrate and the layer containing the fluorescent material, it is preferred that an ultraviolet radiation absorber is contained at least in one of the layers existing between the substrate and the layer containing the fluorescent material.
Overcoat: 3
Another preferred embodiment in the ultraviolet block material comprising a substrate and an ultraviolet block layer provided on the substrate in a releasable manner is a structure in which the ultraviolet block layer has a layer containing a fluorescent material and at least one layer containing an ultraviolet radiation absorber between a substrate and a layer containing a fluorescent material and, in addition, the layer containing the fluorescent material contains a stabilizer.
In this structure, the layer containing a fluorescent material contains a stabilizer and, therefore, decomposition of the fluorescent material can be prevented. Further, since there is a layer containing an ultraviolet radiation absorber between a substrate and a layer containing a fluorescent material, the result is that, under a state that the ultraviolet block layer is adhered on the material to be transferred, the ultraviolet radiation absorber is present outside the layer containing the fluorescent material. Accordingly, especially when the material to be transferred is image, ultraviolet light firstly passes through the layer containing the ultraviolet radiation absorber and then arrives the layer containing the fluorescent material and, therefore, the amount of ultraviolet light arriving the layer containing the fluorescent material can be reduced and decomposition of the fluorescent material by ultraviolet light can be effectively prevented.
In this structure, it is preferred that the structure is in such a manner that there is at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material.
Laminate
One of the embodiments of the ultraviolet block material of the present invention is a structure as shown in FIG. 2 that there are a substrate 2 and an ultraviolet block layer 3 layered on the substrate. In that case, the substrate and the ultraviolet block layer are adhered to such an extent that they are not usually detached.
Such an ultraviolet block material 1 is adhered on the material 8 to be laminated, for example, by the following manner.
First, as shown in FIG. 3A, the side, which is farthest from a substrate, of the ultraviolet block layer 3 of the ultraviolet block material 1 is piled so as to contact the material 8 to be laminated. The farthest surface of the ultraviolet block material from the substrate usually has an adhesive layer 7 in order to make the adhesion with the material to be laminated good. When an image is formed on the surface of the material to be laminated, the surface 9 on which the image is formed and the farthest side of the ultraviolet block layer of the ultraviolet block material from the substrate are piled so as to contact them.
After that, the ultraviolet block layer and the material to be laminated are adhered by means of heating or pressurization. The substrate is not separated from the ultraviolet block layer but is adhered to the material to be laminated together with the ultraviolet block layer. A method where the ultraviolet block material is adhered on the material to be laminated as such is called laminate.
In an ultraviolet block material comprising a substrate and an ultraviolet block layer adhered on the substrate, the side of the substrate opposite to the ultraviolet block layer or the farthest layer from the substrate of the ultraviolet block material may be a layer receiving color materials (or colorants). In such the case above-mentioned, it is possible to form an image protected by the ultraviolet block layer when an image is formed on the color material-receiving layer of the ultraviolet block material of the present invention by means of an ink jet printing method, a thermal transfer printing method or the like, then the color material-receiving layer and the substrate are piled so as to be contacted each other and the ultraviolet block material and the substrate are adhered.
Laminate: 1
In an ultraviolet block material comprising a substrate and an ultraviolet block layer adhered on the substrate, one of the preferred embodiments is such a structure that the ultraviolet block layer has a layer containing a fluorescent material, there is at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material and any of the layers constituting the ultraviolet block layer contains an ultraviolet radiation absorber.
In the case of laminate, after the ultraviolet block material is adhered on the material to be laminated, the substrate is not separated from the ultraviolet block layer and, therefore, there is at least one layer outside of the layer containing the fluorescent material whereby the layer containing the fluorescent material is not exposed to air both before and after adhering to the material to be laminated and the ultraviolet blocking effect can be maintained for a long period.
When at least one layer between the substrate and the layers containing a fluorescent material contains an ultraviolet radiation absorber, the outcome is that the ultraviolet radiation absorber is present outside of the layer containing the fluorescent material under such a state that the ultraviolet block layer is adhered on the material to be laminated. Accordingly, especially in case the material to be laminated is an image, ultraviolet light at first passes through the layer containing the ultraviolet radiation absorber and then arrives the layer containing the fluorescent material whereby the amount of the ultraviolet light arriving the layer containing the fluorescent material can be reduced and the decomposition of the fluorescent material by ultraviolet light can be effectively prevented.
Preferably, the layer containing the fluorescent material contains an ultraviolet radiation absorber. When the layer containing the fluorescent material contains an ultraviolet radiation absorber, that is preferred in such a respect that the amount of ultraviolet light affecting the fluorescent material can be reduced as same as in the above-mentioned case.
Particularly preferred one is a structure where an ultraviolet radiation absorber is contained in a layer containing the fluorescent material and also at least in one layer among the layer existing between the substrate and the layer containing the fluorescent layer. Such a structure is preferred in such a respect that the ultraviolet light affecting the fluorescent material can be further reduced.
Laminate: 2
Another preferred embodiment in an ultraviolet block material comprising a substrate and an ultraviolet block layer adhered on the substrate is such a structure that the ultraviolet block layer comprises a layer containing a fluorescent material and that the layer containing the fluorescent material contains an ultraviolet radiation absorber and a stabilizer.
It is preferred that the ultraviolet block layer has at least one layer between a substrate and a layer containing a fluorescent material and/or has at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material.
Preferably, it is a structure where at least one of the layers existing between a substrate and a layer containing a fluorescent material contains an ultraviolet radiation absorber.
Laminate: 3
Another preferred embodiment in the ultraviolet block material comprising a substrate and an ultraviolet block layer adhered on the substrate is a structure in which the ultraviolet block layer has a layer containing a fluorescent material and at least one layer containing an ultraviolet radiation absorber between a substrate and a layer containing a fluorescent material and, in addition, the layer containing the fluorescent material contains a stabilizer.
Preferably, it is a structure where there is at least one layer on the side, opposite to the substrate, of the layer containing the fluorescent material.
As hereunder, a substrate constituting an ultraviolet block material and an ultraviolet block material will be illustrated.
Substrate
The substrate may be anything which has been known and has some heat resistance and strength. Its examples include polyester film such as polyethylene terephthalate, polystyrene film, polypropylene film, polysulfone film, polyphenylsulfide film and polyethylene naphthalate film and preferred ones are polyester film, paraffin paper, glassine paper and condenser paper. Among the polyester film, particularly preferably used one is a polyethylene terephthalate film. Such a substrate may be either in a sheet or in a continuous film.
Especially in the case of an ultraviolet block material used for laminate, it is preferred that the transmittance of the substrate for the light within a range of 420-800 nm is 90% or more or, preferably, 95% or more.
In the case of an ultraviolet block material used for overcoat, there will be no problem even when the substrate is not transparent.
Thickness of the substrate is usually not less than 0.5 μm or, preferably, not less than 3 μm and usually not more than 100 μm, preferably not more than 50 μm or, more preferably, not more than 10 μm.
When the ultraviolet block layer is provided in a releasable manner, it is preferred that the surface of the substrate 2 or, particularly, the side 10 connecting the ultraviolet block layer has a releasing layer for making the releasing of the ultraviolet block layer good.
The releasing layer is a layer comprising a resin having a low surface energy. To be more specific, waxes, silicone resin and fluorine-containing resin; a product where the above resin is graft-bonded to the side chain of acrylate resin or butyral resin; a hardened product of modified silicone oils; a reaction product of modified silicone oil with an isocyanate compound or an epoxy compound; resin where silicone oil is mixed with resin having a good adhesion to the substrate and the like may be used. Silicone resin of a type which is hardened by ultraviolet light, silicone resin of a thermosetting type and silicone resin of a type which is hardened at room temperature may be used as well.
Thickness of the releasing layer is usually 0.02 μm or more or, preferably, 0.05 μm or more and usually 2 μm or less or, preferably, 1 μm or less.
When the ultraviolet block layer is adhered to the substrate, the surface of the substrate 2 or, particularly, the surface 10 contacting the ultraviolet block layer may have a primer layer for enhancing the adhesion with the ultraviolet block layer.
When the ultraviolet block layer is adhered to the substrate, it is preferred that there is an abrasion-resisting layer at the substrate surface which is opposite to the layer to be adhered. The abrasion-resisting layer is a resin layer having excellent mechanical strength and slipping property.
To be more specific, silicone resin and fluorine resin; a product where silicone resin or fluorine resin is subjected to a graft bonding to polycarbonate, butyral resin or acrylate resin; a hardened product of modified silicone oils; a reaction of product of a modified silicone oil with an isocyanate compound or an epoxy compound; resin having a high mechanical strength by mixing with silicone oils; etc. may be used as a binder. Particles may be added to such a binder for reducing contacting area. With regard to the particles, those which are transparent in a visible region and are transparent when mixed with a binder are selected. Specific examples thereof are silicone particles, silica particles and resin particles. It is preferred that the refractive index of the particles is near that of the binder because transparency of the abrasion-resisting layer becomes high by that. With regard to the resin particles, those which are three-dimensionally cross-linked are preferred for preventing their swelling when dispersed in common organic solvents.
Thickness of the abrasion-resisting layer is usually 0.1 μm or more or, preferably, 0.5μ or more and usually 15 μm or less or, preferably, 5 μm or less.
Ultraviolet Block Layer
Total thickness of the ultraviolet block layer is usually 0.1 μm or more or, preferably, 0.5 μm or more and usually 5 nm or less, preferably 20 μm or less, more preferably, 10 μm or less, particularly preferably 9 μm or less or, most preferably, 6 μm or less. Especially when the ultraviolet block material or the ultraviolet block layer of the present invention is layered on the surface of the image, it is usually 10 μm or less, preferably 9 μm or less or, more preferably, 6 μm or less. Particularly when only the ultraviolet block layer is layered on the material to be transferred, the ultraviolet block layer is hardly cleaved if the ultraviolet block layer is too thick while, when it is too thin, the ultraviolet block layer may be cracked.
In the ultraviolet block layer, the transmittance of the light within a range of 300-380 nm wavelength region is 10% or less, preferably that within a range of 300-390 nm is 10% or less or, particularly preferably, that within a range of 300-400 nm is 10% or less and the transmittance of the light within a range of 420-800 nm is 90% or more or, preferably, 95% or more.
Usually, a layer containing a fluorescent material constituting an ultraviolet block layer comprises a base material and a fluorescent material.
As to the base material of the layer constituting the fluorescent material, resin is usually used. Examples of the resin are those mainly comprising ethyl cellulose, vinyl acetate resin and derivatives thereof, polyolefin, ethylene-vinyl acetate copolymer, acrylate resin and derivatives thereof, polystyrene and copolymers thereof, polyisobutylene, hydrocarbon resin, polyamide resin, polyester resin, polyurethane resin, acryl-urethane resin, epoxy resin, phenoxy resin, and cellulose type resin and other thermoplastic resins.
Thickness of the layer containing the fluorescent material is usually not less than 0.5 μm and usually not more than 10 μm, preferably not more than 9 μm or, particularly preferably, not more than 3 μm.
Examples of the fluorescent material are those which were mentioned already. The amount of the fluorescent material in the layer containing the fluorescent material is appropriately decided depending upon thickness of the layer containing the fluorescent material, titer of the fluorescent material, etc. and is usually not less than 3% by weight, preferably not less than 6% by weight or, particularly preferably, not less than 10% by weight and usually not more than 30% by weight, preferably not more than 25% by weight or, particularly preferably, not more than 20% by weight to the base material.
Thickness of the layer 5 between the substrate and the layer containing the fluorescent material is usually not less than 0.5 μm and usually not more than 10 μm, preferably not more than 9 μm or, particularly preferably, not more than 3 μm. Incidentally, when there are plural layers, the thickness means that of one layer.
With regard to the material constituting the layer existing between the substrate and the layer containing the fluorescent material, the material which is same as that used as the base material for the layer containing the fluorescent material may be used.
When the ultraviolet block layer is provided in a releasable manner on the substrate and there is no releasing layer on the surface of the substrate contacting ultraviolet block layer, it is preferred that the surface nearest the substrate among the layers 5 between the substrate 2 and the layer 4 containing the fluorescent material is a releasing layer.
The releasing layer is peeled together with the ultraviolet block layer from the substrate. The releasing layer is a layer comprising a resin having a low surface energy. To be more specific, there may be used wax, silicone resin, fluorine-containing resin; a product where the above resin is graft-bonded to the side chain of acrylate resin or butyral resin; a hardened product of modified silicone oils; a reaction product of modified silicone oil with an isocyanate compound or an epoxy compound; a resin where silicone oil is mixed with a resin having a good adhesion to the substrate; etc. An ultraviolet-setting silicone resin, a thermosetting silicone resin and a silicone resin setting at room temperature may be advantageously used as well. A product where these resins are compounded to particles is preferably used.
Thickness of the releasing layer is usually not less than 0.02 μm or, preferably, not less than 0.05 μm and usually not more than 2 μm or, preferably, not more than 1 μm.
Thickness of the layer which is in an opposite side of the substrate to the layer containing a fluorescent material is usually not less than 0.5 μm and usually not more than 10 μm, preferably not more than 9 μm or, particularly preferably, not more than 3 μm. Incidentally, when there are plural layers, the thickness means that of one layer.
With regard to the material constituting the layer which is in an opposite side of the substrate to the layer containing the fluorescent material, the substance which is same as that used as the base material for the layer containing the fluorescent material may be used.
It is preferred that the layer 6 farthest from the substrate among the layers provided on the side, opposite to the substrate, of the layer containing the fluorescent material is an adhesive layer 7 having an adhesive property by means of heating or pressurization because, even when the surface of the material to be layered has no adhesive layer, adhesion to the material to be layered is strong. An example of the adhesive layer is a layer comprising a heat-sensitive adhesive and an example of the heat-sensitive adhesive is a resin having substantially no stickiness and having a glass transition point (Tg) of 40-75° C. as described in the Japanese Patent No. 2,999,515. Specific examples are those resins having a good adhesion upon heating such as acrylate resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer or polyester resin. Thickness of the adhesive layer is usually not less than 0.1 μm and not more than 10 μm.
With regard to a color material-receiving layer which is provided in the case of a direct formation of image on an ultraviolet block material, a color material-receiving layer which is suitable for each image forming method such as dye sublimation or dye diffusion thermal transfer, wax type thermal transfer and ink jet may be appropriately selected.
With regard to a color material-receiving layer for a dye sublimation or dye diffusion thermal transfer, known ones may be used and its main component is a thermoplastic resin which is able to receive a thermally sublimating or diffusing dye from a thermal transfer sheet. To be more specific, polyester resin, acrylate resin, polystyrene, styrene type homopolymer, acrylstyrene copolymer, polycarbonate, polysulfone, polyvinylpyrrolidone, polyamide resin, polyvinyl acetal resin, polyvinyl alcohol resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, phenoxy resin, epoxy resin, cellulose ester resin, silicone resin and fluorine resin and the like may be exemplified. Besides those resins, it is possible to add various kinds of plasticizer as well as peeling agents and stabilizers which will be mentioned later.
Examples of a peeling agent are modified silicone oils and a reaction product of modified silicone oil with an isocyanate compound and an epoxy compound.
It is also possible that a color material-receiving layer is cross-linked in a three-dimensional manner for improving the peeling from the thermal transfer sheet and for improving the heat resistance.
In this case, thickness of the color material-receiving layer is usually not less than 1 μm or, preferably, not less than 2 μm and usually not more than 10 μm or, preferably, not more than 5 μm.
With regard to a color material-receiving layer of a wax type thermal transfer, known porous receiving layer and receiving layer having no fine pores may be exemplified.
Examples of the porous receiving layer are those containing a water-dispersible polyurethane resin and, if necessary, pigment as main component(s).
Thickness of the color material-receiving layer in this case is usually not less than 0.5 μm or, preferably, not less than 0.8 μm and usually not more than 20 μm or, preferably, not more than 10 μm.
With regard to a color material-receiving layer for an ink jet method, layers comprising known water-soluble resin and water-insoluble resin may be exemplified. A receiving layer comprising a water-soluble resin is preferred.
With regard to the water-soluble resin, there may be used gelatin, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, polyvinyl alcohol, terminal-modified polyvinyl alcohol, etc. may be used. Such a resin may be compounded with known additives or resin for giving a luster.
When the color material-receiving layer is porous, organic or inorganic fine particles are added for forming fine pores in the color material-receiving layer. Preferably, inorganic fine particles are used and, particularly preferably, white inorganic pigment or the like is used.
Amount of a coating for the color material-receiving layer is usually not less than 0.3 g/m 2 , particularly not less than 1 g/m 2 or, particularly preferably not less than 2 g/m 2 and usually not more than 30 g/m 2 , preferably not more than 25 g/m2 or, particularly preferably, not more than 20 g/m 2 .
In a direct formation of image on an ultraviolet block material, although there is no particular limitation for the substrate paper which is layered on the ultraviolet radiation block material of the present invention, there may be used synthetic paper comprising the resin of polyolefin type, polystyrene type, polyester type, etc. and white non-transparent film or foamed sheet; various paper materials such as high quality paper, art paper, coated paper, cast coated paper, paper impregnated with synthetic resin or emulsion, paper impregnated with synthetic rubber latex, paper lined with synthetic resin, cellulose fiber paper and resin-coated paper where at least one side of the paper has a polyolefin resin-coated layer to which pigment or the like is added (the so-called RC paper); various kinds of plastic films and sheets such as polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate and polycarbonate etc.; and cards made of polyvinyl chloride or the like. When the substrate paper has a poor tight adhesion to the color material-receiving layer, it is preferred to subject its surface to a primer treatment or a corona discharge treatment.
Thickness of the substrate paper is usually about 10-300 μm.
With regard to the ultraviolet radiation absorber, those which were mentioned already may be exemplified. Amount of the ultraviolet radiation absorber in the layer containing an ultraviolet radiation absorber may be appropriately decided depending upon thickness of the layer, titer of the ultraviolet radiation absorber, etc. and is usually not less than 5% by weight, preferably not less than 6% by weight or, more preferably, not less than 10% by weight and usually not more than 30% by weight, preferably not more than 25% by weight or, more preferably, not more than 20% by weight.
A stabilizer is a substance which prevents the decomposition of the fluorescent material by oxygen or ultraviolet light and it is usually contained in the same layer in which the fluorescent material is contained. Although there is no particular limitation for the stabilizer, its specific examples are antioxidant of a hindered amine type, an antioxidant of a hindered phenol type and a light stabilizer of a benzoate type and the like. An ultraviolet radiation absorber may be used as a stabilizer as well.
Examples of an antioxidant of a hindered amine type are bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate such as Tinuvin 770 (a product of Ciba-Geigy); bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate such as Tinuvin 765 (a product of Ciba-Geigy); and bis(1,2,2,6,6-pentamethyl-4-piperidyl) 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate such as Tinuvin 114 (a product of Ciba-Geigy).
Examples of an antioxidant of a hindered phenol type are pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] such as Irganox 1010 (a product of Ciba-Geigy); thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] such as Irganox 1035 (a product of Ciba-Geigy); octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate such as Irganox 1076 (a product of Ciba-Geigy); ethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl-m-tolyl) propionate] such as Irganox 245 (a product of Ciba-Geigy); 2,6-di-tert-butyl-4-[4,6-bis(octylthio)-1,3,5-triazin-2-ylamino]phenol such as Irganox 565 (a product of Ciba-Geigy); and 4,6-bis(octylthiomethyl)-o-cresol such as Irganox 1520 (a product of Ciba-Geigy).
Examples of a light stabilizer of a benzoate type are 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate such as Tinuvin 120 (a product of Ciba-Geigy) and the like.
Amount of the stabilizer to the base material in the layer containing the fluorescent material is usually not less than 1% by weight or, preferably, not less than 3% by weight and usually not more than 15% by weight or, preferably, not more than 10% by weight.
Examples of a method for the formation of each of the layers constituting the ultraviolet block layer on a substrate are gravure coating, reverse gravure coating, roll coating, etc. wherein a solution containing a base material and ultraviolet block materials and/or others for constituting each layer is applied and dried.
Each of the layers constituting the ultraviolet block layer may contain lubricant, particles, surfactant, etc.
When the material to be layered is a printed image by a dye sublimation or dye diffusion thermal transfer or a wax type thermal transfer, the ultraviolet block layer may be placed in such a successive manner with the color material layers on the surface of a color sheet as shown in FIG. 4 .
Examples of the material to be layered with an ultraviolet block layer or a whole ultraviolet block material of the present invention are images such as painting, ink jet printed image, dye sublimation or dye diffusion thermal transfer printed image, wax type thermal transfer printed image and electronic photographic image; glass and transparent plate, such as glass part of picture frame, window glass for cars and homes, showcase and food case; and fluorescent lamp and sleeve for fluorescent lamp.
When the ultraviolet block material of the present invention is layered on various kinds of glass and transparent plate, ultraviolet light does not reach inside them and, therefore, when it is used for a picture frame for example, it is possible to prevent color fading, discoloration, decolorization, etc. of paintings, letters, etc. in the picture frame.
Fluorescent lamp generates ultraviolet light besides the visible light. Insects such as moth have a habit of being attracted by ultraviolet light and, therefore, when the ultraviolet block material of the present invention is layered on window glass, fluorescent lamp or sleeve for fluorescent lamp, it is possible to prevent swarming of the insect.
Although there is no particular limitation for a method of adhering the ultraviolet block layer or the whole ultraviolet block material of the present invention to a material to be layered, it is preferred to adhere by means of heating or pressurization when the material to be layered is image or particularly when it is ink jet printed image, dye sublimation thermal transfer printed image, dye diffusion thermal transfer printed image, wax type thermal transfer printed image, electronic picture image, etc. When the ultraviolet block layer is be placed in such a successive manner with the color material layers on the surface of a color sheet in the case of a thermal transfer print, it is preferred that adhesion is carried out by means of heating.
With regard to a means for heating, it may be carried out by a thermal head in a printer or by hot plate, hot roll, iron, etc.
Examples of the pressurizing means are pressurizing roll, pressuring plate, etc.
EXAMPLES
In the following Examples, Acriloid A21 (an acrylate resin solution; manufactured by Rohm & Haas; a 30% solution), Bilon 103 (saturated polyester resin; manufactured by Toray), PKHC (phenoxy resin; manufactured by Phenoxy Specialties, Rock Hill, S.C.), Tinuvin 328 (ultraviolet radiation absorber; a product of Ciba-Geigy), Uvitex OB (fluorescent material; a product of Ciba-Geigy), Irganox 1076 (antioxidant of a hindered phenol type; manufactured by a product of Ciba-Geigy), Tinuvin 120 (stabilizer of a benzoate type; a product of Ciba-Geigy), 2,2′-dihydroxy-4,4′-dimethoxybenzophenone (ultraviolet radiation absorber of a benzophenone type; hereinafter, abbreviated as “DHDMOBF”), Fluorad FC-430 (surfactant of a fluorine type; a product of 3M), acetylacetone and a mixed solvent (tolune/2-butanone=1/1) were used.
EXAMPLES 1-4 AND COMPARATIVE EXAMPLES 1 and 2
A polyethylene terephthalate film (thickness: 12 μm) having a releasing layer on one side was used as a substrate and an application solution as shown in Table 1 was applied on the releasing layer using a Meyer bar. After being applied, it was dried at 120° C. for 1 minute to form an ultraviolet block layer having a thickness of 2 μm on the substrate.
The light transmittance spectrum of the ultraviolet block material was measured by a spectrophotometer U-3500 manufactured by Hitachi. The result is shown in FIG. 1 .
TABLE 1
(In the Table, figures indicate parts by weight)
Example
Example
Example
Example
Comp.Ex.
Comp.Ex.
1
2
3
4
1
2
Application
C-1
C-2
C-3
C-4
C-5
C-6
solution
Acriloid A21
26.3
27.3
28.4
29.5
30.1
30.8
Tinuvin 328
1.19
1.23
1.28
1.33
1.36
1.38
Uvitex OB
1.58
1.23
0.85
0.44
0.23
0
Irganox
0.24
0.25
0.26
0.27
0.27
0.28
1076
FC 430
0.09
0.10
0.10
0.11
0.11
0.11
Acetylacetone
8.0
8.0
8.0
8.0
8.0
8.0
Mixed Solvent
62.6
61.9
61.1
60.3
59.9
59.5
EXAMPLES 5-17 AND COMPARATIVE EXAMPLE 3
Application solutions were prepared according to the compositions as shown in Table 2.
The solution was applied using a Meyer bar on a releasing layer of a polyethylene terephthalate film (thickness: 12 μm) having a releasing layer on one side as a substrate so as to give layer constitution as shown in Table 3. After being applied, it was dried at 120° C. for 1 minute to prepare an ultraviolet block material.
In Examples 6 and 10-17, the application solution was applied on a substrate and dried to form an ultraviolet block layer. Another application solution was applied on a releasing layer of a polyethylene terephthalate film (hereinafter, referred to as PET) comprising the same materials as the substrate and dried to form an ultraviolet block layer. The ultraviolet block layer on the substrate and the ultraviolet block layer on the PET were piled in a state of contacting each other so as to give the layer constitution as shown in Table 3 and preliminarily provided on an image-receiving layer surface of the image-receiving paper of a video print set (VW-APKC 36) for a printer (NV-AP-1) manufactured by Matsushita Electric Industrial) and its four corners were fixed by an adhesive tape so as not to slip off.
After that, a transparent polyethylene terephthalate film (thickness: 4.5 μm) having a heat-resisting slipping layer on one side and having no color material layer on another side was prepared and a marker similar to a color sheet of VW-APKC 36 was formed thereon followed by winding on a bobbin of a color sheet of VW-APKC 36. The color sheet was installed in a color sheet cassette of VW-APKC 36 and then installed in a printer (NV-AP-1).
In the meanwhile, the above-piled product of the image-receiving paper and the ultraviolet block material was provided in a paper cassette and the highest energy was applied to the thermal head to heat the whole surface so that they were adhered each other. After heating, the ultraviolet block material of the present invention was obtained by taking it out from the image-receiving paper on which it was preliminarily placed.
Incidentally, although the ultraviolet block layer of the present invention contacted the dye-receiving layer of the image-receiving paper upon heating, an adhesive layer was not provided on the outermost layer of the ultraviolet block layer and, therefore, it did not happen that the ultraviolet block layer adhered to the dye-receiving layer.
The ultraviolet radiation block material prepared as such was subjected to a light irradiation test from a xenon lamp using a Ci-4000 weather-o-meter manufactured by Atlas. The irradiation condition was that the irradiated light intensity at 340 nm was 0.55 w/m 2 and the irradiating time was 40 hours. The transmittance spectra of each sample before and after the light irradiation test from xenon lamp were measured by a spectrophotometer U-3500 manufactured by Hitachi. Result of the transmittance spectrum after the irradiation test with a xenon lamp is shown under the column of “light stability” in Table 2.
Incidentally, the light stability was judged according to the following criteria on the basis of the transmittance spectrum of each sample.
In the meanwhile, result of the transmittance spectrum before the light irradiation from a xenon lamp was very good for all of Examples 1-13 and Comparative Example 1.
very good: transmittance of the light of 380 nm was 5% or less
good: transmittance of the light of 380 nm was more than 5% and up to 10%
durable: transmittance of the light of 380 nm was more than 10% and up to 20%
no good: transmittance of the light of 380 nm was more than 20%
TABLE 2
(Figures in the Table indicate part(s) by weight)
Application Solution
C-1′
C-6′
Acriloid A21
26.9
31.6
Tinuvin 328
1.21
1.42
Uvitex OB
1.62
0
FC 430
0.10
0.11
Acetylacetone
8.0
8.0
Mixed Solvent
62.2
58.9
Application Solution
C-7
C-8
C-9
C-10
C-11
C-12
Acriloid A21
70.0
26.3
26.3
26.3
32.3
36.7
Tinuvin 328
1.68
1.19
1.19
1.19
1.21
0
Uvitex OB
2.32
1.58
1.58
1.58
0.0
0
Irganox 1076
0
0.24
0
0
0
0
Tinuvin 120
0
0
0.24
0
0
0
DHDMOBF
0
0
0
0.24
0
0
FC 430
0
0.09
0.09
0.09
0.12
0
Acetylacetone
0
8.0
8.0
8.0
8.0
0
Mixed Solvent
26.0
62.6
62.6
62.6
58.4
63.3
Application Solution
C-13
C-14
Bilon 103
8.08
0
PKHC
0
8.08
Uvitex OB
1.21
1.21
Tinuvin 328
1.62
1.62
FC 430
0.10
0.10
Acetylacetone
8.0
8.0
Mixed Solvent
81.0
81.0
TABLE 3
Constitution of Ultraviolet Block Material
Light Stability
Example 5
Substrate/C-7 (9 μm)
Very good
Example 6
Substrate/C-7 (9 μm)/C-11 (2 μm)/PET
Very good
Example 7
Substrate/C-8 (2 μm)
Good
Example 8
Substrate/C-9 (2 μm)
Durable
Example 9
Substrate/C-10 (2 μm)
Durable
Example 10
Substrate/C-1′ (2 μm)/C-11 (2 μm)/PET
Good
Example 11
Substrate/C-1′ (2 μm)/C-12 (2 μm)/PET
Good
Example 12
Substrate/C-8 (2 μm)/C-11 (2 μm)/PET
Very good
Example 13
Substrate/C-8 (2 μm)/C-12 (2 μm)/PET
Very good
Example 14
Substrate/C-13 (2 μm)/C-11 (2 μm)/PET
Very good
Example 15
Substrate/C-13 (2 μm)/C-12 (2 μm)/PET
Very good
Example 16
Substrate/C-14 (2 μm)/C-11 (2 μm)/PET
Very good
Example 17
Substrate/C-14 (2 μm)/C-12 (2 μm)/PET
Very good
Comparative
Substrate/C-1′ (2 μm)
No good
Example 3
EXAMPLES 18-22 AND COMPARATIVE EXAMPLE 4
The ultraviolet block material of the present invention was adhered onto the image and the light stability of the image was compared.
The ultraviolet block material was prepared by the same manner as in Example 1 so as to give the layer constitution as shown in Table 4. In the case of a layered product where the ultraviolet block layer comprises plural application solutions, the layer nearest the substrate was applied and dried and then the next layer was applied and dried whereupon the ultraviolet block layer was formed.
In the meanwhile, black (gray) which an optical density was about 1 was printed using a printer NV-AP-1 and a video printing set VW-APKC 36 for the said printer manufactured by Matsushita Electric Industrial. Then the printed image of this printed thing was piled to contact the ultraviolet block layer which was provided in a releasable manner in the ultraviolet block material on the substrate and set in the printer, and the whole surface was heated by a thermal head from the back of the color sheet using an color sheet of the video printing set. Since the substrate of the ultraviolet block material was thermally fused to the color sheet, the substrate was separated from the image-receiving layer simultaneously with the completion of the heating and only the ultraviolet block layer was layered on the image.
The image protected by the ultraviolet block layer prepared as such was subjected to a test of light irradiation from a xenon lamp using a Ci-4000 weather-o-meter manufactured by Atlas under the same condition as in Example 1.
The image before and after the light irradiation test was measured by a calorimeter of a Spectroloni type manufactured by Gretag to determine the hue change (ΔE). The result is shown in Table 4. The smaller the ΔE, the smaller the hue change and the better the light stability of the image.
In Comparative Example 4, the hue change was measured without layering an ultraviolet block layer on the image.
TABLE 4
Constitution of Ultraviolet Block Material
ΔE
Example 18
Substrate/C-6′ (2 μm)
9.4
Example 19
Substrate/C-6′ (2 μm)/C-12 (2 μm)
4.2
Example 20
Substrate/C-11 (2 μm)/C-6′ (2 μm)/C-12 (2 μm)
3.7
Example 21
Substrate/C-1′ (2 μm)/C-12 (2 μm)
7.6
Example 22
Substrate/C-11 (2 μm)/C-1′ (2 μm)/C-12 (2 μm)
6.2
Comparative
(none)
15.4
Example 4
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The application discloses a two-layered coating system using an ultraviolet absorber in its inner layer (called the blocking layer), furthest away from the source of ultraviolet exposure, with a fluorescent material that reflects ultraviolet radiation back as blue light. The ultraviolet absorber in the inner layer is used in sufficient concentration to have an ultraviolet cutoff, which can be extended with the fluorescent material. The ultraviolet block material of the present invention has transmittance of the light within a range of wavelength of 300-380 nm of 10% or less, preferably transmittance of the light within a range of wavelength of 300-390 nm of 10% or less, and, particularly preferably, transmittance of the light within a range of 300-400 nm of 10% or less, while it has a transmittance of the light within a range of 420-800 nm wavelength of 90% or more, or, preferably, 95% or more.
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FIELD OF THE INVENTION
The present invention relates to the field of static storage elements; more specifically, it relates to a static random access memory (SRAM) cell using tunnel current loading n-channel field effect transistors (NFETs).
BACKGROUND OF THE INVENTION
Static storage devices such as SRAM cells use a write operation to store data in the cell and a read operation to sense the data stored in the cell. To ensure no read data disturbs occur, the write operation needs to write full power supply voltage levels to the SRAM cell so when the data is read it is not corrupted. In current SRAM cell designs, large P-channel field effect transistors (PFETs) are required to supply retention and write-recovery currents to maintain the full power supply voltage level. As integrated circuits become smaller and denser and as power consumption specifications for battery powered integrated circuits decrease, along with power supply voltages, the present SRAM cell designs are increasingly inefficient in both silicon area used and power consumed.
Therefore, there is a need for writing full power supply voltage levels to SRAM cells that have reduced area requirements and low power consumption.
SUMMARY OF THE INVENTION
The present invention provides an SRAM cell that can be written with full power supply voltage levels and has reduced area requirements and low power consumption compared to conventional SRAM cells by utilizing the tunneling leakage current of load devices to maintain the nodes of the SRAM cell at full power supply voltages levels.
A first aspect of the present invention is an integrated circuit, comprising: a node; a PFET connected between the node and a data signal source, a gate of the PFET coupled to a control signal source; a first NFET connected between the node and ground; and a second NFET, a gate of the second NFET connected to a power supply, a source and a drain of the second NFET both connected to the node.
A second aspect of the present invention is an integrated circuit, comprising: a first node and a second node; a first PFET connected between the first node and a first data signal source, a gate of the first PFET coupled to a control signal source; a second PFET connected between the second node and a second data signal source, a gate of the second PFET coupled to the control signal source; a first NFET connected between the first node and ground, a gate of the first NFET connected to the second node; a second NFET, a gate of the second NFET connected to a power supply, a source and a drain of the second NFET both connected to the first node; a third NFET connected between ground and the second node, a gate of the third NFET connected to the first node; and a fourth NFET, a gate of the fourth NFET connected to the power supply, a source and a drain of the fourth NFET both connected to the second node.
A third aspect of the present invention is a method, comprising: providing an SRAM cell, the SRAM cell comprising: a first node and a second node; a first PFET connected between the first node and a true bitline, a gate of the first PFET coupled to a wordline; a second PFET connected between the second node and a complimentary bitline, a gate of the second PFET coupled to the wordline; a first NFET connected between the first node and ground, a gate of the first NFET connected to the second node; a second NFET, a gate of the second NFET connected to a power supply, a source and a drain of the second NFET both connected to the first node; a third NFET connected between ground and the second node, a gate of the third NFET connected to the first node; and a fourth NFET, a gate of the fourth NFET connected to the power supply, a source and a drain of the fourth NFET both connected to the second node.
BRIEF DESCRIPTION OF DRAWINGS
The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic circuit diagram of an SRAM cell according to the present invention;
FIG. 2 is a read-cycle simulation of an SRAM cell according to the present invention;
FIG. 3 is a plot of NFET gate current versus gate dielectric thickness for various gate voltages;
FIG. 4 is a plot of NFET gate tunneling current as a function of temperature;
FIG. 5 is a plot of the slope AN 1 (for an NFET) as a function of gate voltage;
FIG. 6 is a plot of the magnitude of the intercept AN 2 (for an NFET) as a function of gate voltage; and
FIG. 7 is a cross-sectional view through an NFET.
DETAILED DESCRIPTION OF THE INVENTION
For the purposes of the present invention the term gate current, tunneling leakage current and gate tunneling leakage current should be considered as equivalent terms. It should be understood that the structure of PFETs and NFETs used in the present invention in their simplest form comprise a gate electrode over a gate dielectric over a channel region in a semiconductor substrate with a source and a drain formed in the substrate on opposite sides of the channel region. However, more structurally complex PFETs and NFETs as known in the art may be used as well.
FIG. 1 is a schematic circuit diagram of an SRAM cell according to the present invention. In FIG. 1 , an SRAM cell 100 includes PFETs T 1 and T 2 and NFETs T 3 , T 4 , T 5 and T 6 . The source of PFET T 1 is coupled to bitline BLC (bitline complement), the drain of PFET T 1 is coupled to a node NC and the gate of PFET T 1 is coupled to a wordline WL. The source of PFET T 2 is coupled to bitline BLT (bitline true), the drain of PFET T 2 is coupled to a node NT and the gate of PFET T 2 is coupled to wordline WL. The source of NFET T 3 is coupled to GND (ground), the drain of NFET T 3 is coupled to node NC and the gate of NFET T 3 is coupled to node NT. The source of NFET T 4 is coupled to GND, the drain of NFET T 4 is coupled to node NT and the gate of NFET T 4 is coupled to node NC. The source and drain of NFET T 5 are coupled to node NC and the gate of NFET T 5 is coupled to VDD 1 . The source and drain of NFET T 6 are coupled to node NT and the gate of NFET T 6 is coupled to VDD 1 . Wordline WL carries a control signal often referred to a wordline signal, thus wordline WL may be considered a control signal source. Bitlines BLC and BLT carry data bit signals and may be considered data signal sources. Wordline WL, and bitlines BLC and BLT are supplied from a power supply VDD 2 . In a first example VDD 1 is equal to VDD 2 . In a second example VDD 1 is greater than VDD 2 . The term full POWER SUPPLY voltage swing when applied to read and write operations of SRAM cell 100 refers to a swing between VDD 1 and GND of node NC or node NT and a swing between VDD 2 and GND of the signal on bitline BLC or bitline BLT.
To write a logical 1 to SRAM cell 100 wordline WL is turned on (at GND), turning PFETs T 1 and T 2 on, so with bitline BLT at GND and bitline BLC at VDD 2 , node NC rises to VDD 2 and node NT falls to GND.
To write a logical 0 to SRAM cell 100 wordline WL is turned on (at GND), turning on PFETs T 1 and T 2 , so with bitline BLC at GND and bitline BLT at VDD 2 , node NC falls to GND and node NT rises to VDD 2 .
Because of current leakage through NFET T 3 and T 4 respective nodes NC or NT will discharge over time and the voltage level on nodes NC or NT will drop. It is the node (NC or NT) at VDD 2 that is of concern for leakage current. If the voltage drops to a predetermined level below VDD 2 , read stability and read performance specifications may be compromised and data errors on read operations may occur.
NFETS T 5 and T 6 supply retention current to respective nodes NC or NT to compensate for the leakage through NFETs T 3 and T 4 by keeping the HIGH node at VDD 1 and the LOW node is at GND.
There are two types of gate tunneling current leakage, inversion tunneling current leakage and accumulation tunneling current leakage. Inversion tunneling current leakage occurs when the gate of an NFET is at VDD 2 . Accumulation tunneling current leakage occurs when the gate of an NFET is at GND. NFETs T 5 and T 6 are load devices operated in inversion mode in SRAM cell 100 .
The write recovery operation is also of concern because the node NT or NC must be pulled to VDD 2 very quickly and that requires a substantial amount of current. In conventional SRAM cells NFETs T 5 and T 6 are PFET devices that pull the internal nodes NC or NT to VDD 2 . Generally, without NFETs T 5 and T 6 , the node (NT or NC) would discharge from VDD 2 due to current leakage through NFETs T 3 or T 4 .
In the example of SRAM cell 100 storing a logical 1 (NT at GND NC at VDD 2 ), the retention current (which is a gate tunneling current) supplied by NFET T 5 (I TUNT5 ) should be about equal to or greater than the sub-threshold voltage leakage current through NFET T 3 (I SUBVTT3 ) plus the gate tunneling current through NFET T 4 (I TUNT4 ) minus the sub-threshold voltage leakage current through PFET T 1 (I SUBVTT1 ). It should be understood that I TUNT5 and I TUNT4 are inversion gate tunneling currents through NFETs T 5 and T 4 respectively and that I SUBVTT1 and I SUBVTT3 are sub-threshold voltage leakage currents through PFET T 1 and NFET T 3 respectively.
In the example of SRAM cell 100 storing a logical 0 (NT at VDD 2 , NC at GND), the retention current (which is a gate tunneling current) supplied by NFET T 6 (I TUNT6 ) should be greater than the sub-threshold voltage leakage current through NFET T 4 (I SUBVTT4 ) plus the gate tunneling current through NFET T 3 (I TUNT3 ) minus the sub-threshold voltage leakage current through PFET T 2 (I SUBVTT2 ). Again, it should be understood that I TUNT6 and I TUNT3 are inversion gate tunneling currents through NFETs T 6 and T 3 , respectively and that I SUBVTT2 and I SUBVTT4 are sub-threshold voltage leakage currents through PFET T 2 and NFET T 4 , respectively.
The amount of gate tunneling inversion current through NFET T 6 (or NFET T 5 ) is controlled by the value of VDD 1 , the gate dielectric thickness and the dielectric constant of the gate dielectric. When comparing gate dielectric thicknesses, electrically equivalent gate dielectric thicknesses are compared. The electrically equivalent gate dielectric thickness takes into account the different permittivity of different dielectric materials, because it is possible for a thin layer of a dielectric material with a high permittivity to have a higher electrically equivalent gate dielectric thickness than a physically thicker layer of a dielectric material with a lower permittivity. Since thermal silicon oxide is a traditional, well characterized and common dielectric material, gate dielectric thickness is often described in terms of thermal silicon oxide equivalent (T OXEQ ) thickness which is the physical thickness of the gate dielectric multiplied by the ratio of the permittivity of thermal silicon oxide divided by the permittivity of the material of the gate dielectric.
In one example, the area of gate over channel region of NFETs T 5 and T 6 may be greater than the area of gate over channel region of NFETs T 3 and T 4 to allow for more current drive to maintain respective nodes NC or NT at VDD 2 . In one example, the T OXEQ of PFETs T 1 and T 2 may be about the same as the T OXEQ of NFETs T 5 and T 6 to take advantage of the fact that sub-threshold leakage through PFETs T 1 or T 2 will also help to maintain nodes NC or NT respectively at VDD 2 .
FIG. 2 is a read-cycle simulation of an SRAM cell according to the present invention. Reference to FIG. 1 during the following discussion will be helpful. In FIG. 2 , the SRAM cell is holding a logical 0 (node NT at VDD 2 and node NC at GND). As wordline WL is turned on (transitions from high voltage to low voltage) node NT and bitline BLT remain at the full power supply voltage, node NC charges to about 10% of the power supply voltage and bitline BLC discharges to about 90% of the power supply-voltage. As wordline WL is turned off (transitions from low voltage to high voltage) node NT and bitline BLT remain at a full power supply voltage level, node NC discharges to GND and bitline BLC is pre-charged to a full power supply voltage level. Thus, operation of an SRAM cell according to the present invention is highly reliable in terms of read stability.
FIGS. 3 through 6 and the discussion infra describe determination of NFET gate current (tunneling leakage) in amperes/um 2 as a function of temperature, T OXEQ and gate voltage (V G ) and are useful in designing SRAM cell 100 (see FIG. 1 ).
FIG. 3 is a plot of NFET gate current versus gate dielectric thickness for various gate voltages. All curves were plotted for NFETs at 25° C. with the NFETs in inversion mode. In FIG. 3 , curve 105 is for a gate voltage of 0.2 volts, curve 110 is for a gate voltage of 0.4 volts curve 115 is for a gate voltage of 0.6 volts, curve 120 is for a gate voltage of 0.8 volts and curve 125 is for a gate voltage of 1.0 volts. The gate dielectric thickness (T OXEQ ) has been measured electrically in FIG. 3 . FIG. 3 illustrates that gate current on a natural logarithmic scale is a linear function of T OXEQ where the slope and intercept of the straight-line function are functions of the gate voltage. (Note, because the gate current is a log scale, the slopes of curves 105 , 110 , 125 , 120 and 125 are parallel, but the slopes increase from curve 105 through 125 .) FIG. 3 may be used, in a first example, to select appropriate T OXEQ values for NFETs T 3 , T 4 , T 5 and T 6 (see FIG. 1 ) when operated at the same voltages to ensure more gate tunneling leakage current through NFETs T 5 and T 6 than through NFETs T 3 and T 4 .
FIG. 4 is a plot of NFET gate tunneling current as a function of temperature. From FIG. 4 , the activation energy ΔH may be calculated to be 0.017 eV.
Returning to FIG. 3 , the equation for curves 105 through 125 may be written in the form of equation (1):
ln( I G )=( AN 1 ×T OXEQ )+ AN 2 (1)
where: I G is the gate tunneling leakage current in amperes/um 2 , AN 1 is the slope, which is itself a function of gate voltage (see FIG. 5 and equation 2 infra), AN 2 is the T OXEQ intercept (the gate dielectric thickness axis of FIG. 3 ), hereafter intercept, which is itself a function of gate voltage (see FIG. 6 and equation 3 infra) and T OXEQ is the gate dielectric thickness in nm. Equation (1) is for 25° C. only. A more general equation for any temperature is given by equation (4) described infra.
FIG. 5 is a plot of the slope AN 1 (for an NFET) as a function of gate voltage. The equation for FIG. 5 is:
AN 1=(0.673ln( V G ))−9.917 (2)
where: V G is the gate voltage in volts.
FIG. 6 is a plot of the magnitude of the intercept AN 2 (for an NFET) as a function of gate voltage. The equation for AN 2 is:
AN 2=−9.685 e (−1.159×VG) (3)
where: V G is the gate voltage in volts.
Equation (4) is a more general version of equation (1) for any temperature:
ln( I G )=( AN 1 ×T OXEQ )+ AN 2 +{ΔH [(1 /T 1)]/ K} (4)
where: K is Bolztmann's constant,
T 1 is 298° K. (25° C.), and T 2 is the operating temperature of the NFET is an SRAM cell in ° K.
Equation (4) reduces to equation (1) when T 2 =25° C.
FIG. 7 is a cross-sectional view through an NFET. In FIG. 7 , an NFET 130 includes a gate dielectric 135 formed on a top surface of a silicon substrate 140 , a gate electrode 145 formed over a channel region 150 in a P-well 155 in substrate 140 and a source 160 and a drain 165 formed on opposites sides of channel region 150 . NFET 130 is surrounded by shallow trench isolation (STI) 170 . Spacers 175 are formed on opposite sides of gate electrode 145 . The physical thickness of gate dielectric 135 is D 1 . Equation (4) may be used to determine a T OXEQ based on a value of I G for NFETS T 5 and T 6 (also T 3 and T 4 ) (see FIG. 1 ) required to meet stability and performance specifications for SRAM cell 100 (see FIG. 1 ). A value for D 1 may then be determined from the calculated T OXEQ and the dielectric constant of dielectric layer 135 .
Thus, the present invention provides an SRAM cell capable of writing full power supply voltage levels and also provides reduced area requirements and low power consumption.
The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention.
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An SRAM cell with gate tunneling load devices. The SRAM cell uses PFET wordline transistors and NFET cross-coupled transistors. The PFET wordline transistors are fully conductive during read operations, thus a full voltage level is passed through the PFET to the high node of the cell from the bitline. Tunnel current load devices maintain the high node of the cell at full voltage level during standby state.
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TECHNICAL FIELD
This invention pertains generally to power amplifiers and more specifically to power amplifiers for use with radio frequency (RF) signals.
BACKGROUND OF THE INVENTION
Temperature tracking of bias supplies for linear RF power amplifiers is essential for stable operation. As is known, all bipolar transistors--including RF power devices--exhibit a negative temperature coefficient in the base-emitter turn-on voltage drop. Consequently, thermal run-away will result when an RF power transistor is biased with a fixed, non-temperature-tracking voltage source.
It is accepted practice to avoid this run-away situation by using a thermally-variable device such as a diode or a diode-connected transistor mounted on the heat sink near the RF power device. This is not ideal, however, because of the thermal lag between the RF device and the sensor due to the thermal resistances and masses involved.
As is known, an improvement in response will result if the temperature-sensing diode is physically as close as possible to the transistor die contained in the RF package. In many practical cases, however, unless a special package is employed in which the sensing diode is internal and is mounted next to the transistor die, this implies mounting the sensing diode on the RF device package. A problem arises with this approach, however, since the high RF field around the RF power transistor causes rectification in the temperature-sensing diode with a polarity opposite to the bias voltage. As a result, the bias voltage decreases with increasing RF drive and the amplifier input-output transfer characteristic displays a significant non-linearity. In some severe cases, a low-frequency blocking type oscillation may also result.
As a result of the above, there is a need for an improved RF power amplifier.
SUMMARY OF THE INVENTION
Accordingly, an improved RF power amplifier is disclosed whereby a PIN-type diode is utilized to provide temperature tracking for the bias supply. The PIN diode provides proper temperature tracking with the bias supply while exhibiting reduced sensitivity to self-rectification. As a result, the power amplifier's bias supply is more stable and less susceptible in inaccuracies, distortion, and oscillation that may be caused by self-rectification in the presence of high RF fields, especially at UHF and 800 MHz.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing a first embodiment of an RF power amplifier, according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to FIG. 1, there is a circuit diagram showing a first embodiment of an RF power amplifier, according to the invention.
As shown, an RF input signal is coupled to the base of an RF power transistor 5 via lead 37, thereby generating an amplified signal at the transistor 5's collector which, in turn, is coupled to an output lead 7. The RF power transistor 5, for example, may be conveniently mounted inside an RF power transistor package 9.
Also shown is a bias source, as follows: a first transistor 11, a first resistor 13, a second resistor 15, a third resistor 17, and a first diode 19 form a temperature-compensated current source for the diode string consisting of a second diode 21 and a third diode 23 that is a PIN-type. The diodes 19 and 21 are conventional silicon devices. The PIN diode 23 is generally mounted on top of the RF power transistor package 9. The cathode of the PIN diode 23 is grounded at the RF power transistor 5 and a single wire 25 connects the PIN 23's anode to the diode 21's cathode. Diode 21 is used to temperature-compensate a second transistor 27 that couples the bias source to the RF power transistor 5. Those skilled in the art will also appreciate that transistor 27 provides bias current to the RF transistor 5 via lead 37. Also, transistor 27 acts to isolate, or buffer, the bias source from the RF power transistor 5.
The ratio of the resistor 13 and the resistor 15 establishes the current through the diode stack consisting of diode 21 and PIN diode 23, and ultimately provides a fine control of the bias voltage output 29 available at the emitter of the transistor 27. A fourth resistor 33 provides a minimum load for the transistor 27 in the absence of RF drive via the signal input 3. A capacitor 31 (low-pass) filters the bias source by averaging the bias current pulses drawn by transistor 5's base even at the lowest component of the frequency spectrum of the envelope applied to the transistor. Additionally, capacitor 31 should present a low impedance at the frequency of operation of the RF amplifier. The requirement that capacitor 31 bypass both low frequencies and RF is usually met by having capacitor 31 consist of two or more individual capacitors--each providing bypassing action at the required frequency range. Capacitor 31, in conjunction with inductor 35, comprises an RF low-pass filter and prevents, or at least impedes, RF energy from entering the bias source.
In operation, the bias voltage present on lead 37 is thermally controlled by the temperature characteristic (TC) of the PIN diode 23 which closely matches the temperature coefficient of transistor 5's "turn-on" voltage. As the RF power transistor 5 heats up, the voltage across the diode stack consisting of diode 21 and PIN diode 23 drops and lowers the bias voltage on lead 37 to compensate for the RF transistor 5's reduced base-emitter "turn-on" voltage.
The first embodiment depicted in FIG. 1 may be analyzed as follows:
The transistor 11, the diode 19, and the resistors 13, 15, and 17 form a current source that acts to maintain the current through PIN diode 23 at a constant value, thereby generating a bias voltage 25 at the anode of PIN diode 23 with respect to a fixed reference voltage, such as ground 39. This PIN bias voltage 25 is then transmitted, or coupled, to lead 37 and, in turn, to the base of the RF power output transistor 5 by a bias-coupling circuit formed by diode 21, transistor 27, resistor 33, capacitor 31 and inductor 35. As a result, the voltage at the lead 37 and, in turn, the voltage at the base of transistor 5 is essentially equal to the PIN bias voltage 25. Therefore, the difference between these two voltages is essentially zero.
To provide temperature compensation for transistor 5, PIN diode 23 is mounted in close proximity to transistor 5. Ideally, the PIN diode 23 would be mounted inside the RF power transistor package 9 next to the transistor die contained therein if fabrication of a special package were feasible. Otherwise, PIN diode 23 may be mounted on top of the RF power package 9 or as close thermally to the RF transistor die as possible. Therefore, the temperature of the PIN 23 should track (or be identical to) the temperature of transistor 5. Therefore, the difference between these two temperatures is essentially zero.
Capacitor 31 regulates or filters the bias voltage applied to the base of transistor 5 (via lead 37) in the presence of low-frequency envelope modulation. The RF filter formed by the combination of capacitor 31 and inductor 35 attenuates RF signals present on lead 37 that would otherwise tend to flow toward the bias source connected to lead 29 and potentially disrupt operation of the bias source due to rectification of RF in the transistors and diodes comprising that bias source. Further, bias current and isolation are provided by buffer transistor 27, while bising diode 21 compensates for the forward-biased base-emitter junction of transistor 27.
Referring again to FIG. 1, a second embodiment of an RF power amplifier, according to the invention, connects the transistor 5 in a common-base configuration, instead of the common-emitter configuration discussed above. This embodiment is achieved by substituting input 41 (shown in broken lines) for input 3 thereby applying the RF input signal to transistor 5's emitter, instead of the base. The emitter also is returned to ground through an inductor 43 (shown in broken lines) which presents a high impedance to the RF drive signal present at input 41. Finally, transistor 5's base is provided with a good RF bypass to ground through a capacitor 45 (shown in broken lines). The output 7 remains coupled to the collector of transistor 5. It will be apparent to those skilled in the art that the DC and biasing connections for the resulting common-base configuration are identical to the common-emitter configuration. This second embodiment therefore enjoys the same benefits as the first embodiment discussed above.
One advantage of the invention over the prior art is accurate and rapid-tracking temperature sensing in the presence of substantial RF fields. Another advantage is physical simplification and reduced manufacturing costs through the elimination of bypassing and decoupling components that would be required with a conventional diode temperature sensor.
Potential applications for this invention include linear RF power amplifiers for RF transmitters employing any spectrally efficient modulation scheme that generates envelope modulation as part of the modulation format. Such spectrally efficient non-constant envelope schemes include QAM, filtered QPSK and SSB. Another potential application would be in linear RF power amplifiers used as common power amplifiers to amplify several channels simultaneously. Such applications, for example, may become popular for digital cellular base stations.
While various embodiments of the RF power amplifier, according to the invention, have been described herein, the scope of the invention is defined by the following claims.
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An improved RF power amplifier is disclosed whereby a PIN-type diode is utilized to provide temperature tracking for the bias supply. The PIN diode provides proper temperature tracking with the bias supply while exhibiting reduced sensitivity to self-rectification. As a result, the power amplifier's bias supply is more stable and less susceptible to inaccuracies, distortion, and oscillation that may be caused by self-rectification in the presence of high RF fields, especially at UHF and 800 MHz.
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This is a division, of U.S. patent application Ser. No. 08/022,073, filed Feb. 24, 1993 now U.S. Pat. No. 5,404,936.
BACKGROUND OF THE INVENTION
The invention relates to a heatable roll for a paper machine, paper finishing machine, or equivalent. The roll is heated by a heating medium which is introduced into the roll interior through at least one of the ends of the roll. The heating medium acts upon the material of the roll mantle, or the material of the roll, and is arranged to flow across the axial length of the roll. Thereafter, the heating medium is arranged to flow out of the roll through either one of the ends of the roll, i.e. the same end through which the heating medium entered into the roll or an opposite end.
The invention also relates to a method for heating a roll for use in paper machines, paper finishing machines or other paper machines. A heat transfer medium is introduced into a roll, circulated through the roll and removed from the roll. In this manner, the material of the roll mantle or the material of the roll is heated.
Further, the invention also relates to a method for maintaining a substantially constant temperature on an outer surface of the roll over which a paper web or board will pass.
In paper machines and paper finishing machines, in particular in calenders and super-calenders, heatable rolls are commonly used. The rolls are heated by means of a heat-transfer medium, such as hot water or oil.
There are mainly two different types of heatable rolls in the prior art. The first type of heatable rolls have a roll mantle, or are massive rolls, wherein substantially axial bores are formed in proximity to the outer face of the roll. The heating medium is made to flow through the bores from one end of the roll to an opposite end of the roll. Generally, a number of such bores are provided in the roll and are uniformly spaced in the direction of the circumference of the roll. The heating medium may be arranged to circulate in the bores either once in a direction from one end of the roll to the other, or twice, or even several times, so that in adjacent bores the heating medium flows in opposite directions. One such so-called "drilled roll" has been described earlier, e.g., in published European Patent Application No. EP-0 158 220.
On the other hand, a second type of heatable roll is a so-called double-mantle roll or rolls provided with an interior piece. This type of heatable roll is commonly used in paper machines. In this type of roll, an interior piece is fitted inside the roll mantle so that an annular intermediate space remains between the interior piece and an inner face of the roll mantle. The heating medium circulates in the annular space from one end of the roll to the other end of the roll. One such roll provided with an interior piece is described, e.g., in Finnish Patent No. 74,069.
A problem in prior art heatable rolls is that owing to the construction of the rolls, the profiles of the surface temperature in the rolls are almost always uneven. The rising differences in temperature in the axial direction of the roll are influenced by the construction and size of the roll. In rolls provided with interior pieces, typical differences in the surface temperature, on the surface over which the web runs, in the axial direction of the roll are in the range about 3° C. to about 6° C. On the other hand, in drilled rolls, a typical reduction of the surface temperature between the ends of the bores in the roll is in the range of about 3° C. while the maximum difference in temperature in the axial direction of the roll is in the range of about 9° C. and the difference in temperature in a cross-sectional plane of the roll is in the range of about 6° C.
The temperature differences in both types of prior art rolls produce dangerous and very detrimental thermal strains in the roll. Deformations which can be noticed in the smoothness of the paper, and which deteriorate the runnability of the machine, are also caused by such temperature differences. Therefore, a commonly imposed requirement on the variations in temperature in the working face, i.e. the outer face, of a roll is in the range of about ±1.5° C. Thus, in prior art rolls, it is a significant drawback that the rolls have not been able to conform with this requirement.
Reference is also made to U.S. Pat. No. 4,658,486 (Schonemann) which describes a heatable calendar roll having axial passages formed in the roll mantle for circulating a heating medium. However, it is a significant drawback that the roll described in this reference does not provide a substantially uniform temperature along the axial length of the roll mantle. This is because there are no means provided to increase the coefficient of heat transfer in the roll material in the flow direction of the heating medium.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention is to provide a heatable roll which is an improvement over prior art heatable rolls.
It is another object of the present invention to provide a new and improved method to heat a roll used in a paper machine.
It is yet another object of the present invention to provide a heatable roll having a face in which the differences in temperature are substantially lower than in prior art devices and substantially constant along the axial length of the roll and which rolls comply with the preferred requirements imposed on rolls by users of the rolls in paper machines.
It is still another object of the present invention to provide a new and improved roll in which the coefficient of heat transfer to the outer face of the roll increases as the heat transfer medium flows through the roll.
In view of achieving these objects, and others, the roll in accordance with the invention is provided with means by which the coefficient of heat transfer from the flowing heating medium that acts upon the material of the roll mantle to the material of the roll is increased in the flow direction of the heating medium.
The present invention provides a number of important advantages in comparison to prior art devices. In the present invention, the surface temperature of the roll mantle can be made substantially uniform and the amount of the heating medium used for the heating of the roll can be reduced substantially. For these reasons, the pumping capacity of the heating medium that is needed to heat the roll is not as high as in prior art devices. Moreover, a uniform temperature of the roll mantle has a highly favorable and significant effect on the quality of the paper. It is a further remarkable advantage that, by means of simple operations and/or modifications, the invention can be applied to existing prior art rolls.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 is a schematic, partly sectional longitudinal view of a drilled roll in accordance with the invention and used in a method in accordance with the invention.
FIG. 2 is a schematic cross-sectional view taken along the line II--II in FIG. 1.
FIG. 3 is a partial perspective view of the roll mantle of a drilled roll as shown in FIG. 1 and of an insulation piece in accordance with the invention arranged in one bore in the roll mantle.
FIG. 4 is a schematic, longitudinal sectional view of a roll provided with a displacement piece in accordance with the invention.
FIG. 5 is a schematic, partly sectional longitudinal view of a drilled roll in accordance with the invention and used in a method in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1, 2, 3 and 5, a heatable roll in accordance with the present invention is denoted generally with the reference numeral 10. The roll 10 comprises a roll mantle 11 having a pair of ends arranged on opposite axial sides of the roll. Roll ends 13,14 are fixed to each of the ends of the roll mantle 11 and are provided with axle journals 15,16, respectively. Bores 17 are arranged in the roll mantle 11 in proximity to an outer face, or surface, 12 of the roll 10. The bores 17 may be drilled into the roll mantle and extend from one end of the roll to an opposite end of the roll. In the embodiments shown in FIGS. 1, 2 and 3, bores 17 are arranged to run substantially in the axial direction of the roll 10.
As shown in FIG. 2, several bores 17 are arranged in the circumferential direction of the roll 10 and are distributed substantially evenly over the circumference. An axial central bore 18 is arranged to pass through the first roll end 13 of the roll and into the axle journal 15 provided therein. The axial central bore 18 may be formed, e.g., by drilling, through the material of the roll 10 and roll end 13. A pipe 19 or equivalent is placed through the central bore 18 and extends into the second roll end 14. The diameter of the pipe 19 is smaller than that of the central bore 18, so that an annular gap remains between the pipe and the central bore 18.
A heating medium is introduced into the roll 10 through the pipe 19. The heating medium flows into radial bores 14a formed in the second roll end 14 opposite the first roll end 13 so that the heating medium flows across the axial length of the roll 10 from one end to an opposite end of the roll such that the entire surface of the roll is heated. Radial bores 14a extend from the pipe 19 in a center portion of the roll 10 into bores 17 placed in the roll mantle 11. In a corresponding manner, radial bores 13a are formed in the first roll end 13 and extend from the bores 17 in the roll mantle into the annular gap in the central bore 18 placed in the first end. Thus, the heating medium flows from the pipe 19 through the radial bores 14a placed in the second roll end 14 into the bores 17 extending from end to end in the roll mantle 11, and from the bores 17 through the radial bores 13a formed in the first roll end 13 into the central bore 18 and further out of the roll 10.
In the embodiments shown in FIGS. 1,2 and 3, the coefficient of heat transfer from the flowing heating medium to the material of the roll mantle 11 is increased in the flow direction of the heating medium by providing suitable means in the roll mantle 11. For example, insulation pieces 1 can be arranged in each of the bores 17 of the roll mantle 11. The insulation pieces 1 might be provided with an outer shell having a decreasing thickness in the flow direction of the heating medium through the bores.
According to FIG. 3, the insulation pieces may consist, e.g., of a tube made of plastic or some other insulation material, into which tube an opening 2 has been formed. The opening 2 is parallel to the longitudinal, i.e. axial, direction of the tube and extends from one end of the tube to an opposite end so that the heating medium can flow therethrough. The size of the opening increases in the flow direction of the heating medium. The opening 2 in the tube is directed towards the outer face 12 of the roll mantle 11. Thus, in the embodiment illustrated in FIG. 3, the proportion of the material of the roll mantle 11 with which the heating medium is in direct contact is increased in the flow direction.
In this embodiment, since the temperature of the heating medium is lowered in the direction of the flow and since, on the other hand, the heating medium can act upon an increasing proportion of the material of the roll mantle 11 in the direction of the flow, the temperature of the roll mantle 11, and thus the outer surface of the roll, is not substantially changed in the axial direction of the roll. The reason the temperature of the heating medium is lowered is because a portion of the heat energy contained within the heating medium is transferred to the roll mantle to heat the roll as the heating medium progresses through the bores 17.
The insulation piece 1 may also be shaped in a manner different from that illustrated in FIGS. 1, 2 and 3. The main point is, however, that the insulation piece 1 should be shaped so that the transfer of heat is restricted in a controlled way in the axial direction of the roll, i.e. in the flow direction. In the manner, the surface temperatures on the roll 10 can be made uniform. At the same time, the conduction of heat can be guided efficiently towards the roll face 12.
In a preferred embodiment, a tubular piece is utilized as the insulation piece 1. In this embodiment, it is possible to accomplish the advantageous heat conduction so that the inner face of the tubular insulation piece 1 becomes conically wider in the flow direction, i.e. the interior diameter increases in the flow direction of the heating medium. In this embodiment, the wall thickness of the tube will become smaller in the flow direction. However, this is more difficult to arrange in practice than the formation of an opening 2 into a tubular insulation 1, which was described above.
In a drilled roll 10, as shown in FIG. 5 the invention may also be realized, for example, so that the inner surface 17a of the bores 17 formed into the roll mantle 11 are roughened. In this embodiment, the degree of roughness of the inner faces of the bores 17 is larger towards the second end of the bores 17, as compared with the first end through which the heating medium begins to flow through the bores 17. In this manner, it is possible to intensify the transfer of heat in the flow direction. This is, however, also more difficult to effect than the embodiment described above.
FIG. 4 shows a heatable roll provided with a displacement piece in accordance with the invention, which roll is denoted generally with the reference numeral 20. The roll 20 comprises a roll mantle 21 having a pair of opposite ends to which roll ends 23 and 24 are fixed. Roll ends 23,24 are provided with axle journals 25 and 26, respectively. The roll ends 23,24 are also provided with central through axial bores 27,28. In the interior of the roll mantle 21, a displacement piece 29 has been arranged. The displacement piece 29 is attached to the roll ends 23,24 by means of end pieces 30,31.
The diameter of the displacement piece 29 is smaller than the diameter of the interior of the roll mantle 21 so that an annular intermediate space 34 remains between the displacement piece 29 and the inner face of the roll mantle 35. Several through holes 32,33 have been formed into the circumference of both of the end pieces 30 and 31 of the displacement piece 29. Holes 32 and 33 are opened into the annular intermediate space 4.
The heating medium is introduced into the roll 20 through the axial bore 27 in the first roll end 23, from which it is passed through the holes 32 in the first end piece 30 into the intermediate space 34 between the displacement piece 29 and the roll mantle 21. In the intermediate space 34, the heating medium flows into the other end of the roll, from which it is passed through the holes 33 in the second end piece 31 into the axial bore 28 placed in the second roll end 24, and from there further out of the roll 20.
In the embodiment shown in FIG. 4, the coefficient of heat transfer from the flowing heating medium to the material of the roll mantle 21 is increased in the flow direction. This is accomplished by applying or producing a coating 3 on the inner face 35 of the roll mantle. The coating 3 is produced by any known process, e.g., by spraying, which coating is arranged so that the thickest portion of the coating is at the initial end of the flow, i.e. the end of the space 34 through which the heating medium enters. The thickness of the coating 3 is reduced in the flow direction towards the opposite end of the roll.
The coating 3 is made of a suitable insulation material, such as plastic or equivalent. Thus, at the initial end of the flow, where the temperature of the heating medium is highest, the thickness of the coating 3 that functions as an insulation layer is the largest. Therefore, the transfer of heat from the heating medium to the material of the roll mantle 21 is lowest at this point. In a corresponding manner, the thickness of the coating is reduced towards the other end of the roll, whereby the transfer of heat from the heating medium to the material of the roll mantle 21 becomes easier because the coefficient of heat transfer is higher. By means of this arrangement, the situation is achieved so that the temperature of the outer face 22 of the roll mantle is substantially uniform and invariable over the axial length of the roll.
In the embodiment of FIG. 4, in accordance with the invention, the change in the coefficient of heat transfer from the flowing heating medium to the material of the roll mantle can also be accomplished, e.g., so that the inner face 35 of the roll mantle is roughened so that its inner face is smoothest at the initial end of the flow and roughest at the final end of the flow.
In another embodiment, the insulation material 3 may consist of a net-like solution, or a tubular insulation, having an open area which increases towards the second and final end of the flow. Thus, the surface temperature of the roll mantle will be maintained substantially uniform because the heating medium cools as it progresses along the axial length of the tubular insulation. This is a result of the transfer of heat from the heating medium to the roll mantle through the tubular insulation. However, the coefficient of heat transfer will increase as the heating medium cools so that a substantially constant temperature will be present in the roll mantle.
In a corresponding manner, in the embodiments illustrated in FIGS. 1, 2 and 3, the tubes arranged in the bores in the roll mantle may be perforated, or have porous, net-like openings, i.e. so that the open area of the tubes or net is increased towards the second end of the roll.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
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The invention relates to a method for heating a roll and a heatable roll for use in a paper machine, paper finishing machine, or equivalent. The roll is heated by a heating medium which is introduced into the roll interior through at least one of the ends of the roll. The heating medium acts upon the material of the roll mantle or the roll and is arranged to flow across the axial length of the roll. The heating medium is arranged to flow out of the roll through either one of the ends of the roll. The roll is provided with means by which the coefficient of heat transfer from the flowing heating medium to the material of the roll is increased in the flow direction of the heating medium.
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FIELD OF THE INVENTION
[0001] This invention relates to a mechanism and method for enhancing the performance of reciprocating piston internal combustion engines, pumps, and compressors by utilizing a crankshaft that generates an Epitrochoidal path. The piston will be made to dwell at the lower part of its travel, enhancing the cylinder output of the engine, pump or compressor through better utilization of available pressure.
BACKGROUND OF THE INVENTION
[0002] Since the development of the first commercially successful internal combustion engine in the 1860's by Otto and Langen, there have been constant attempts to improve the internal combustion engine. The results of those attempts are apparent everywhere and the internal combustion engine is common throughout the world and used in countless applications, including but not limited to transportation, power generation, construction, agriculture, recreational vehicles, and garden implements, to name a few. In addition to multiple applications, internal combustion engines are available for a variety of fuels, including diesel, gasoline and natural gas.
[0003] Although there are several other types of internal combustion engines such as the gas turbine and rotary, the most common type is the reciprocating piston engine. This engine operates in a cycle with four phases: intake, compression, power (expansion), and exhaust. The piston travels between a Top Dead Center position (hereafter abbreviated as “TDC”), which denotes its highest point of travel, and a Bottom Dead Center position (hereafter abbreviated as “BDC”), which denotes it lowest point of travel. The distance the piston travels between TDC and BDC is a fixed distance, and is commonly referred to as the stroke of the piston. This type of engine is either a two-stroke cycle or a four-stroke cycle. A two-stroke cycle engine requires two piston strokes (or one full revolution of the crankshaft) to complete all phases of operation, while the four-stroke cycle engine requires four piston strokes (or two full revolutions of the crankshaft) to complete all phases of its operation. Separation of each phase of operation is not a distinct division from the other phases. Time, in the form of crankshaft angle of rotation, is ‘borrowed’ from each of the phases such that each phase is transitioned into the next by overlapping or, in the case of the two-stroke cycle engines, combining phases.
[0004] In the typical reciprocating piston engine, the piston travels in a cylinder bore or cylindrical housing between TDC and BDC, and a connecting rod joins the piston to a crankpin on the crankshaft. The crankpin is located a set distance from the centerline of the crankshaft. In this typical configuration, the path of the crankpin as the crankshaft rotates is a circle, and the diameter of the circle is identical to the stroke value. The various parameters within this configuration such as piston diameter and stroke (determined by the crankpin location) can be changed but the basic linkage remains the same. Attempts to enhance an internal combustion engine within this configuration have been limited to some extent by the physical and mechanical properties of the materials used to construct the engine, as well as the thermodynamic properties of the fuel and its delivery into the cylinder.
[0005] There have been attempts to modify the basic linkage described above by altering the crankshaft action, varying the stroke, or changing the Compression Ratio (hereafter abbreviated as “CR”). For example, Moore U.S. Pat. No. 6,453,869 sought to increase efficiency by extending the piston dwell point at TDC and improving connecting rod leverage through a crankshaft provided with an eccentric member. Shaw U.S. Pat. No. 6,526,935 sought to increase fuel efficiency and torque by having the orbiting crankshafts trace a heart shaped pattern and providing means to adjust the CR during operation. In Gonzales U.S. Pat. No. 5,927,236, it is claimed that thermo-efficiency of an internal combustion engine was increased by varying the stroke length and imposing a larger expansion stroke and a shorter intake stroke. Schaal U.S. Pat. No. 5,158,047 claims to increase net engine efficiency by decreasing piston velocity in the first half of the power stroke by allowing more time for cylinder pressure to increase.
[0006] The unrealized advantages associated with the previous attempts have been overcome by the present invention. In contrast to previous attempts to alter the crankshaft action by extending piston dwell at TDC, the present invention maximizes piston dwell at BDC. Although there have been many attempts to cause a piston to dwell at or near TDC, or to maximize the leverage that acts to turn the crankshaft, it would appear that such a dwell should allow the fuel mixture trapped within the combustion chamber to more fully burn and reach a higher initial pressure while the available volume is small. An increased leverage or moment arm, caused by the geometry of the engine components and combined with this increased pressure, should result in more force acting to rotate the crankshaft and result in increased torque output from the engine. However, there are several reasons why these advantages cannot be realized.
[0007] A piston that dwells at or near TDC causes the fuel mixture (or air in a diesel) to preheat before the ignition phase is initiated by the introduction of a spark or fuel. All surfaces within the engine are heated by the combustion of the fuel mixture from previous power strokes, and the newly inducted fuel mixture absorbs some of this heat, in addition to the heat produced during the compression cycle. Heating the fuel mixture prior to having it trapped within the cylinder reduces its density, which means less fuel mixture is ultimately trapped for compression and power production. Detonation of the fuel mixture during this dwell period is very likely and would force the lowering of the CR to a point where engine efficiency would suffer. In order for a piston to be held at or near its TDC position while the crankshaft continues to rotate and build leverage, particularly after the combustion process has been initiated, considerable force must be applied to the piston. The rising cylinder pressure, combined with the available leverage, would tend to force the piston down the cylinder bore, which would apply a force to the crankshaft that would attempt to rotate the crankshaft in the opposite direction than intended. Until the piston is traveling down in the cylinder bore, all effort to hold it at or near TDC is against the intended direction of rotation. The net result of this negative effort is a reduction in the engine's output.
[0008] Dwell of the piston at or near TDC requires a considerable amount of crankshaft rotation to be committed to this effort and, since time is elapsing, less time and crankshaft rotation will be available to complete the other phases of engine operation. Time consumed at or near TDC results in less time being available to push the piston down the bore, scavenge the exhaust gases from the cylinder, and/or to refill the cylinder with the next fuel mixture. Without sufficient time to separate and accomplish these individual events completely, the engine's efficiency will suffer due to the overlapping of the required events, and some mixing of exhaust residue with the fresh fuel mixture will result.
[0009] Holding the piston at or near TDC while the crankshaft continues to rotate results in an increase in the lever arm on the crankshaft. Intuitively, an increased lever arm would seem to allow more torque or rotational force to be transmitted to the crankshaft with the same amount of force applied. However, such is not the case in the referenced attempts.
[0010] Viewed idealistically, the output of an internal combustion engine during a single power phase is dependant on only two variables that affect a piston of specific area: 1) The force derived from the pressure the burning fuel mixture produces within the cylinder, and 2) the distance that that pressure pushes the piston down the cylinder bore before being vented. Once the pressure within the cylinder is released, the power phase ends, even though the piston continues to travel down the cylinder bore to BDC. If the variables of force and distance remain unchanged, the total torque output of the power phase will always be the same, regardless of the crankshaft design or configuration employed. When advantages are claimed from increasing the dwell of the piston at or near TDC, there is no mention of the loss of time that the engine will suffer in getting the next fuel mixture into the cylinder. In a similar manner, claims of increases in leverage or moment arm fail to mention that on a per-degree basis, the pressure above the piston's crown falls at a more rapid rate, destroying any potential torque gains. The increased leverage causes the piston to move a greater distance for every degree of crankshaft rotation, which increases the trapped volume within the cylinder. This lowers the pressure within the cylinder and results in a loss of force to act on the increased moment arm. The total amount of torque applied to the crankshaft over the duration of the entire power phase will be no greater than the amount of torque produced by a conventional style of crankshaft. Therefore, any increases in engine output must be gained through increasing the work done on the piston, yet prior attempts that altered crankshaft motion were unable to achieve this result.
[0011] Work done on the piston is calculated by using the formula for work, which is as follows:
Work=Force×Distance
[0012] The inventive crankshaft is able to increase the work done on the piston through gains in cylinder force (pressure×piston area) and travel (distance.)
[0013] Using this formula in the context of a piston driven engine, the work done on a single piston is the product of the force provided by the pressure produced from the heat of fuel combustion acting on the crown of the piston and the distance the piston travels in its bore while that pressure acts on it. While the formula and the concept are fairly straightforward to understand, the accurate depiction of the work produced involves some detailed analysis. For instance, the pressure produced within a combustion chamber and cylinder bore varies directly with the volume of that cylinder space. If the piston is at the beginning point of its travel away from TDC at the beginning of the power phase, the pressure is high due to the minimum combustion space above it. As the pressure acts on the piston's crown and causes it to move down the bore, the volume within the combustion space and cylinder increases due to the displacement of the piston. This in turn lowers the pressure within the combustion space considerably. At some point in the travel of the piston, the exhaust phase is initiated, either by the piston uncovering an exhaust port or by an exhaust valve opening. Through either mechanism, an escape path for the trapped pressure is provided. As soon as the exhaust port or valve is opened, the force driving the piston down the cylinder bore is diverted out of the cylinder and the work done on the piston comes to an end. It must be remembered that the piston continues to move to the end of its full travel (to BDC) with no force acting to push it further down its bore. Work on the piston is no longer being performed.
[0014] Since the pressure within the cylinder is changing with the piston movement, the force acting on the piston's crown is also changing. Therefore, a single value for force cannot be directly entered into the work formula. However, the force within the cylinder can be calculated at various points along the piston's travel, based on the cylinder volume at those points and the initial starting pressure. The total distance traveled by the piston while acted upon by cylinder pressure is then summed at each point (this can also be found through integration.) In other words, the volume above the piston crown can be accurately calculated by the use of simple geometry and knowing the piston's position in the cylinder, and the resulting pressure found through the application of Boyle's law. This simplified view does not address thermodynamic considerations, but the example is relevant in this application.
[0015] There are several advantages to extending piston dwell at BDC. The piston will reach TDC quicker than an engine with a similar stroke and operating at a similar rate of speed, allowing less time for the trapped fuel mixture to absorb heat from the surrounding surfaces and preheat. This will tend to ward off the undesirable condition of detonation, and it will then be possible to raise the CR to attain more efficiency.
[0016] Ignition timing is usually set to occur at some point as the piston is still approaching TDC during the compression stroke. Typically, a spark is introduced in the cylinder at a point in the crankshaft rotation before TDC (hereafter abbreviated as “BTDC”), which, through geometry, can be equated to a distance that the piston is away from its TDC position. This is done to enable the spark to ignite the fuel mixture while the cylinder pressure is rising due to compression. Time is required to achieve a complete burn to occur, but the rate of burn is also influenced by the rate of pressure rise within the cylinder. If the piston is dwelling at BDC, it will be moving a greater distance per degree of crankshaft rotation during the rise to the top of the cylinder bore. If the spark is to occur at the same distance from TDC as in a standard engine, through geometry it can be seen that the number of crankshaft degrees before the piston reaches TDC will be less. The rate of pressure rise will be greater than in a standard engine, so the ignition phase can be made to occur at fewer degrees of crankshaft rotation before TDC. This will lessen the negative work done on the piston, which will tend to rotate the engine in the opposite direction than intended, and the net result will be a greater power output.
[0017] By allowing the piston to recede away from TDC quickly, there is considerably less time for the heat from the combustion of the fuel mixture to soak into the surrounding surfaces. The heat retained within the combustion gases is more fully utilized to produce pressure to act upon the piston's crown. Since less heat is deposited within the surrounding cylinder surfaces, the next inducted fuel mixture charge will have a cooler environment to enter into, resulting in a denser fuel charge, promoting efficient combustion and greater engine output.
[0018] By maximizing the piston dwell at or near BDC, the piston will travel to the bottom region of the bore in less time than a conventional engine or one that has its piston dwell at or near TDC could accomplish. This will occur when all engine designs are rotating at the same rate, generating the same number of Revolutions Per Minute (hereafter abbreviated as “RPM”.) In the engine that has its piston dwell at or near BDC, there will be an increased amount of time that the piston will be at the bottom of the piston stroke. Therefore, the piston can be moved a greater distance down the cylinder bore with pressure above it and still have the proper amount of time to scavenge the cylinder and refill it with fresh fuel mixture. Also, the distance the piston moves during the compression phase can be increased as well. This means that a larger volume of fuel mixture can be trapped at the beginning of every compression phase. If the actual CR were to be retained at a value identical to a standard engine, the volume of the combustion chamber must be increased as well, resulting in even greater trapped volume than would normally occur. Since the output of the engine is closely tied to the volume of fuel mixture inducted into the cylinder during each intake phase, the additional trapped volume will produce more heat and pressure within the cylinder during the power phase and will result in an increase in engine output.
[0019] Since the volume of the intake charge is now enhanced, the rate of pressure drop during the entire power phase will be slower. From TDC to the end of the power phase, the starting and ending cylinder pressures will be identical to those in a conventional engine with identical displacement, but the piston will have traveled a greater distance in the process. The actual cylinder pressure for every increment of piston movement will favor the cylinder with the larger initial volume of fuel mixture since the changes in piston position will have less influence on the total volume containing the pressure.
[0020] In the present invention, during the time that the piston will dwell at or near BDC, cylinder pressure will be at its lowest value, having allowed for the maximum expansion of the combustion gases to occur against the piston crown. During the exhaust phase, sufficient time is now available to allow the exhaust gases to leave the cylinder under their own pressure differential and without having to be pumped out by the piston. This will result in less work for the piston to do on the exhaust gases remaining in the cylinder at the end of the exhaust phase. The net result to the engine's power output will be increased since little or no energy from the power stroke will have to be invested in pumping pressurized exhaust gases out of the cylinder.
SUMMARY OF THE INVENTION
[0021] It is accordingly an object of the present invention to provide a mechanism and method for improving an internal combustion engine, a pump or compressor to increase the power output and enhance efficiency.
[0022] It is another object of the present invention to provide a mechanism and method for modifying the crankshaft of a reciprocating internal combustion engine, pump or compressor to generate an Epitrochoidal path for the lower end of the connecting rod to travel, resulting in the extended dwell of the piston at or near BDC. This path is generated by a member eccentrically mounted within the lower end of the connecting rod with the eccentric offset distance (or eccentricity) matched to the piston stroke and connecting rod lengths to maximize piston dwell and minimize connecting rod angles.
[0023] It is a further object of this invention to provide an improved mechanism in a machine with at least one cylindrical housing with a central axis having at least one reciprocating piston traveling in the cylindrical housing along the central axis between a top dead center position and a bottom dead center position, a crankshaft rotatably mounted in a crankcase in said machine for rotation about a crank axis with at least one crankpin radially disposed on said crankshaft and having a crankpin axis parallel to the crank axis, and a connecting rod with an upper end pivotally attached to said piston at an upper end journal and a lower end pivotally attached to said crankpin at a lower end journal, said upper end pivoting about an upper end journal axis parallel to said crank axis and said lower end pivoting about a lower end journal axis parallel to said crank axis; said improved mechanism comprising an eccentric bearing with an axially eccentric journal having an eccentric journal axis parallel to the lower end journal axis and offset from the crankpin axis, said eccentric bearing interposed between the lower end and crankpin to generate a noncircular path for the lower end during rotation of the crankshaft in the crankcase. It is also intended that said noncircular path be an epitrochoid and such epitrochoid path extends the time spent by the piston dwelling at or near bottom dead center position in the cylindrical housing during rotation of the crankshaft in the crankcase, and that this invention be equally applicable to machines operating on a four stroke or a two stroke cycle.
[0024] It is also an object of this invention that the distance between the upper end journal axis and the lower end journal axis is the radius of an arc which matches a lower portion of the epitrochoidal path during the time spent by the piston dwelling at or near bottom dead center position in the cylindrical housing during rotation of the crankshaft in the crankcase.
[0025] It is an object of this invention that one embodiment of the improved mechanism shall further comprise; at least one planetary gear set including at least one stationary sun gear fixedly attached to the crankcase with a sun gear axis in line with the crank axis, a revolving planet gear with a planet gear axis parallel to the sun gear axis and in mesh with the sun gear and of pitch diameter equal to the sun gear, the eccentric bearing mounted to the planet gear with the eccentric journal axis parallel to the planet gear axis and offset from the planet gear axis, and said eccentric bearing rotatably mounted in the lower end journal, and the crankpin rotatably mounted in the eccentric journal.
[0026] It is an object of this invention that an alternative embodiment of the improved mechanism shall further comprise; at least one internal toothed gear fixedly mounted to the crankcase with said internal toothed gear having an axis in line with the crank axis, at least one first spur gear with a first spur gear axis parallel to the axis of the internal toothed gear and in mesh with the internal toothed gear, at least one second spur gear with a second spur gear axis parallel to the axis of the first spur gear and in mesh with the first spur gear, the eccentric bearing mounted to the second spur gear with the eccentric journal axis parallel to the second spur gear axis and offset from the second spur gear axis, said eccentric bearing rotatably mounted in the lower end journal, and the crankpin rotatably mounted in the eccentric journal.
[0027] It is a further object of this invention to provide a method of enhancing the performance of a machine with at least one cylindrical housing with a central axis having at least one reciprocating piston traveling in the cylindrical housing along the central axis between a top dead center position and a bottom dead center position, a crankshaft rotatably mounted in a crankcase in said machine for rotation about a crank axis with at least one crankpin radially disposed on said crankshaft and having a crankpin axis parallel to the crank axis, and a connecting rod with an upper end pivotally attached to said piston at an upper end journal and a lower end pivotally attached to said crankpin at a lower end journal, said upper end pivoting about an upper end journal axis parallel to said crank axis and said lower end pivoting about a lower end journal axis parallel to said crank axis; comprising the steps of, providing an eccentric bearing with an axially eccentric journal and eccentric journal axis parallel to the lower end journal axis, placing said eccentric bearing in the lower end journal, placing the crankpin in the eccentric journal where the eccentric bearing journal axis is parallel to and offset from the crankpin axis, and causing the lower end to follow a noncircular path during rotation of the crankshaft in the crankcase. It is also intended that said noncircular path be an epitrochoid and such epitrochoid path extends the time spent by the piston dwelling at or near bottom dead center position in the cylindrical housing during rotation of the crankshaft in the crankcase, and that this method be equally applicable to machines operating on a four stroke or a two stroke cycle.
[0028] It is also an object of this inventive method to provide that the distance between the upper end journal axis and the lower end journal axis is the radius of an arc which matches a lower portion of the epitrochoidal path during the time spent by the piston dwelling at or near bottom dead center position in the cylindrical housing during rotation of the crankshaft in the crankcase.
[0029] It is also an object of this inventive method that one embodiment further comprises the steps of; providing at least one planetary gear set including at least one stationary sun gear fixedly attached to the crankcase with a sun gear axis in line with the crank axis, providing a revolving planet gear with a planet gear axis parallel to the sun gear axis and in mesh with the sun gear and of pitch diameter equal to the sun gear, mounting an eccentric bearing to the planet gear with the eccentric journal axis parallel to the planet gear axis and offset from the planet gear axis, and rotatably mounting said eccentric bearing in the lower end journal, and rotatably mounting the crankpin in the eccentric journal.
[0030] It is also an object of this inventive method that an alternative embodiment shall further comprise the steps of; providing at least one internal toothed gear fixedly mounted to the crankcase with said internal toothed gear having an axis in line with the crank axis, providing at least one first spur gear with a first spur gear axis parallel to the axis of the internal toothed gear and in mesh with the internal toothed gear, providing at least one second spur gear with a second spur gear axis parallel to the axis of the first spur gear and in mesh with the first spur gear, mounting the eccentric bearing to the second spur gear with the eccentric journal axis parallel to the second spur gear axis and offset from the second spur gear axis, rotatably mounting said eccentric bearing in the lower end journal, and rotatably mounting the crankpin in the eccentric journal.
[0031] It is another object of this inventive method that it be applicable to machines with at least one fixed exhaust port in the cylindrical housing further comprising the step of resizing and relocating the exhaust port along the axis of the cylindrical housing. Likewise, the inventive method shall be applicable to machines with at least one fixed intake port in the cylindrical housing further comprising the step of resizing and relocating the intake port along the axis of the cylindrical housing.
[0032] A crankshaft, expressed in simplest terms, is nothing more than a lever arm. The amount of rotational force transmitted by the lever arm is a function of the arm's effective length, the force acting upon it, and the direction from which the force is applied. Conventional piston driven internal combustion engines all utilize a crankshaft to convert their piston's reciprocating motion to a rotational motion. The problem with this arrangement is that the majority of the force acting on the lever arm is not applied when the actual effective moment arm is greatest in length during each power phase. As the crankshaft rotates, the effective moment arm lengthens but the force diminishes. The combination of force and effective moment arm length available during each power phase is multiplied by the frequency of the power pulses. The result is the measured output of the engine (neglecting friction.) The inventive Epitrochoidal crankshaft combines the majority of the available force with a modified moment arm in such a manner that the resulting output of an engine utilizing this crankshaft will be greater than an engine with a conventional style crankshaft of equal stroke. However, the enhanced power output is not due to an increased moment arm alone. The increase in available leverage makes it possible for the piston to travel further in the cylinder bore with pressure acting upon it, and that is where the power increase is realized. The increased length of the power phase and the better utilization of the trapped combustion gases combine to create more work on the piston during each power phase. The decrease in the moment arm at the bottom of the Epitrochoidal pattern, combined with the proper connecting rod length, cause the piston to sit virtually motionless for a significant amount of time, as measured in crankshaft angle of rotation. This time is utilized to empty the cylinder of exhaust gases and refill the cylinder with a fresh fuel charge without borrowing from the power phase. The outcome of the enhanced power phase with the piston dwell at or near BDC is a more powerful and efficient engine.
[0033] Engines with standard style crankshafts have their crankpins fixed at a specific distance from the center of the crankshaft. During the rotation of the crankshaft, the crankpin will travel in a circle. The diameter of that circle is the distance known as the stroke of the engine, and the piston travels the same distance in the cylinder bore, since it is joined to the crankpin through the connecting rod. In an engine equipped with an Epitrochoidal crankshaft, the crankpin also travels in a circle. However, the connecting rod is not directly attached to the crankpin. Instead, the lower end of the connecting rod is fitted over an eccentric bearing, which, in turn, is fitted over the crankpin and indexed in its location through gearing. The combination of the eccentricity of the bearing, the length of the connecting rod, the stroke of the crankshaft, and the indexing of the gearing all determine the path of the lower end of the connecting rod. However, the distance the piston travels in its bore is still the stroke of the engine, regardless of this different crankshaft arrangement. In the standard engine, the bottom of the connecting rod follows the circle generated by the crankpin, whereas in the inventive engine, the bottom of the connecting rod travels in an Epitrochoidal path. The eccentric bearing and its related gearing cause the path to exactly repeat with every rotation of the crankshaft, and the path can be oriented in any direction, based on the initial indexing of the gearing. The crankpin path in a standard engine is a fixed radius, since the crankpin is located a specific distance from the center of the crankshaft. The Epitrochoidal path continuously changes its radius due to the rotation of the eccentric bearing. Also, the Epitrochoidal path, when superimposed over the circular path produced by a standard crankshaft, is further from the center in some portions of the path and closer in others, all while sharing a common center of rotation. The length of the produced moment arm, measured from the center of the crankshaft to the point of applied force is constantly changing, as well. Therefore, both the changing radius and the increased moment arm contribute to the increased power output that the inventive design can produce. Increases in moment arm are directly responsible for increasing the piston's speed away from TDC so that it can reach the bottom of its stroke quicker, which contributes a longer distance of piston travel with pressure acting above it. The increases in the radius at the bottom of the produced pattern allow the piston to dwell at or near BDC since the arc swung by the on-centers length of the connecting rod is optimized to closely match the Epitrochoidal path. The variables of connecting rod length, desired stroke, and offset of the eccentric bearing must all be matched in order to produce the maximum piston dwell and minimize connecting rod angles.
[0034] By using the Epitrochoidal crankshaft, a torque curve generated during a single power phase will yield a higher peak torque value than a standard style crankshaft of similar stroke. This is accomplished through the longer moment arm that can be produced with the appropriate gearing and orientation of the eccentric bearing, combined with the pressure within the cylinder acting on the piston crown. Since work is dependent on piston travel and force, it must be understood that any crankshaft will produce the same total torque effort for a given piston area, travel while under pressure, and initial cylinder pressure. If, for example, the combustion chamber is a fixed volume and the initial pressure within it is always the same, work output will be the same, regardless of the type of crankshaft fitted in the engine provided the piston travels the same distance while pressure acts on it. If the crankshaft used has an extremely long stroke, the total piston movement will be greater, due to the longer moment arm. However, the distance the piston moves after the exhaust phase begins will occur without the aid of cylinder pressure. That means, to obtain more work during the power phase, a given piston must travel a greater distance while pressure acts upon it or the initial combustion chamber pressure must be greater. The product of the two variables, force and distance, must be greater.
[0035] Any point on the circular path of a standard crankshaft's crankpin can be equated to degrees of crankshaft rotation, which in turn can be used to determine piston position. Likewise, any point on the path produced by the Epitrochoidal crankshaft equipped engine can be equated to crankshaft orientation and piston position. However, when identical crankshaft angles of rotation are compared between the two styles of crankshafts, the piston position is not the same, except at TDC and BDC. The rate at which the two pistons move within their respective cylinder bores is different when comparing the two crankshaft designs.
[0036] While turning at the same RPM, an engine equipped with the Epitrochoidal crankshaft will cause the piston to move away from the top of the bore quicker than a piston installed in an engine with a standard style crankshaft of similar stroke. This is due to the increased moment arm generated by the eccentric bearing and followed by the path of the lower end of the connecting rod. The longer moment arm causes the piston to accelerate away from TDC faster. However, when the piston in this engine approaches the bottom of its stroke, the rate of movement is slower than the piston in an engine equipped with a standard style of crankshaft. This is due to the shorter moment arm, which affects the path of the connecting rod's lower end. Again, it is the combination of desired stroke length, offset within the eccentric bearing, and connecting rod length that determines the actual moment arm length at any given point in the rotation of the inventive engine design. The important difference between an Epitrochoidal crankshaft equipped engine and a standard crankshaft equipped engine is that when total piston travel is held constant, the moment arm of the Epitrochoidal crankshaft equipped engine is greater in some points of crankshaft rotation and lesser in others. Piston movement within the bore of a standard crankshaft equipped engine is determined by the crankshaft stroke. That stroke is also a measure of the diameter of the circle that the crankpin follows. The diameter, which is a constant, determines the maximum moment arm that the piston and connecting rod can act on. Since the Epitrochoidal crankshaft equipped engine causes the lower end of the connecting rod to travel in a non-circular path, the moment arm can be made greater during the phase of the power stroke when pressure on the piston crown can act on the crankshaft more advantageously. Since the displacement of the cylinder is held constant, the non-circular path pulls the lower end of the connecting rod closer to the center of the crankshaft and, since the path has a radius matched to the on-centers length of the connecting rod, the piston will dwell at or near BDC. The pressure within the cylinder is made to act on a longer moment arm and to push the piston a greater distance. Both of these attributes contribute to a greater engine output while the dwell at the bottom of the cylinder bore allows sufficient time for the exhaust phase to occur.
[0037] Displacement is the term used to express the size of an internal combustion engine. It is derived from the product of a single cylinder's cross-sectional area, the distance the piston travels from TDC to BDC, and the number of cylinders in the engine. It depicts the volume of air the engine can ingest, based on the volume change created by the movement of the piston(s). In the calculation for displacement, no mention is made concerning several engine factors such as the volume of the combustion chamber, the CR, or whether the engine operates on a two- or four-stroke cycle. Also, the method of induction (normally aspirated or forced induction) or the distance a piston travels while pressure acts on its upper surface does not influence the displacement calculation. The volume of the trapped fuel mixture is determined by measuring the volume within the cylinder when the last escape route out of the cylinder is closed. This occurs somewhere in the rotation of the crankshaft normally depicted as the compression phase, when the piston has already begun its upward travel in the cylinder bore. In the standard engine, the last escape path is closed at a point well beyond BDC. The actual volume and mass of the fuel charge is then somewhat less than the volume of the cylinder head plus the cylinder displacement. The piston, having traveled up the cylinder bore and made the total volume within the cylinder less than its maximum value, will tend to regurgitate a portion of the fuel charge back out of the cylinder until it is trapped, especially at lower engine speeds. Standard engines suffer from the fact that the momentum of their fuel charges is immediately met with a pressure rise in the cylinder they are trying to enter since the piston, upon reaching the bottom of the cylinder bore, immediately reverses its direction and begins to rise in the cylinder. The incoming fuel mixture is now stalled due to the increasing pressure and decreasing volume within the cylinder before the intake valve closes. The net result is that the rising piston displaces a portion of the fuel charge during every intake phase, and the trapped fuel mixture volume is always less than the total cylinder displacement. Only at elevated engine speeds does the cylinder manage to trap the greatest volume of fuel mixture when the momentum of the fuel charge is able to overcome the movement of the mixture displaced out of the cylinder. In the Epitrochoidal crankshaft equipped engine, the piston will dwell at the bottom of the cylinder bore, and the maximum volume will be available for the fuel charge to enter. The last escape route out of the cylinder can then be closed off while the volume is great, and a much larger volume of fuel mixture will be trapped within the cylinder. During the compression stroke, the increased volume will be compressed into the volume available at the cylinder head. If the Epitrochoidal crankshaft equipped engine is to maintain the original trapped CR at a value matching that of the standard engine, the volume at the cylinder head will have to have been increased. Otherwise, the actual CR will be too high, and detonation and overheating will be likely. Increasing the cylinder head volume adds even greater volume to the total volume of fuel mixture trapped within the cylinder at the beginning of the compression stroke. Since the displacement of an engine is dependant on the total distance the piston travels during its stroke within the cylinder bore, the Epitrochoidal crankshaft equipped engine can be designed to have a piston stroke identical to the stroke of a standard crankshaft equipped engine, which will not affect the displacement of the engine. However, the Epitrochoidal crankshaft equipped engine will ingest more fuel mixture for every power stroke and, since power output is directly related to the volume of fuel mixture trapped within the cylinder, the engine will produce more power for a given displacement.
[0038] The advantages to be derived from the present invention can be classified as increasing power for a given displacement or increasing efficiency for fuel economy reasons. Power and efficiency increases can be realized in either two- or four-stroke cycle engines. There is a finite amount of energy in a finite amount of fuel, and the described invention extracts more useable pressure from the burning of its fuel charge before expelling the exhaust gases. All engines must expel exhaust gases from their cylinders in order to have enough time to refill their cylinders for the next power stoke. This occurs as the piston is still moving down the cylinder, and effectively ends the amount of work done on the piston. In a two-stroke engine equipped solely with ports in its cylinder, the port heights and widths are fixed since the ports are simply holes in the cylinder wall, although some highly developed racing engines have an exhaust port that can change height depending on the RPM of the engine. The term Time-Area (hereafter abbreviated as “TA”) represents a value that expresses the amount of time that an area is exposed for the flow of gases through it. Valves or cylinder ports cannot be made to open instantaneously, which would allow them to pass the largest volume of gases for a given amount of time. Rather, they open and close incrementally. Two stroke cycle engines utilizing ports have their area maximized at either TDC or BDC only, since some degree of masking by the piston occurs at all other points of piston position. Four stroke cycle engines (and some two stroke cycle engines) that are equipped with poppet valves must allow the valves to come off of their seats, rise to some maximum height, and then return to their seats. The TA value determines the RPM range in which the port or conduit is most efficient. Regardless of engine speed, the exposed area of the port or conduit will always be the same. However, as the RPM of the engine rises, the time between each of the operating cycles gets shorter, affecting the ability of the port to flow the proper volume of gases necessary for efficient engine operation. Due to the variance in the time component, ports or conduits cannot have a fixed TA value. The value must be determined at a particular engine speed.
[0039] As engine speed is increased, the time between each phase of operation, whether two or four stroke cycle, is decreased. At some engine speed, determined by the porting or valve timing established by the engine manufacturer, peak torque output is achieved, which is the point where the highest Volumetric Efficiency occurs. Volumetric Efficiency is a measure of the ability of the engine to draw in the maximum amount of fuel mixture into each cylinder. When an engine is running, each phase of the engine's operation requires some measure of time in order for a volume of gases to pass through either a port or a valve. As engine speeds increase, the time to accomplish these phases gets shorter while the volume of gas increases and the area of the port or valve remains constant. At some RPM, the amount of time available for the passage of those gases becomes insufficient to get the phase fully completed since the ports or valves become a choke point to the gas flow.
[0040] In a two stroke cycle prototype of an Epitrochoidal crankshaft equipped engine (hereafter, the “inventive prototype” or “inventive prototype engine”), the piston speed up and down the cylinder bore varies from the speed of a piston in a standard engine operating at the same RPM. In the original standard engine, the sizes of the ports within the cylinder were chosen by the manufacturer to provide a smooth idle, easy starting, and some RPM potential. In the inventive prototype, the port sizes are physically different than the standard engine's ports, but the port TA values are identical to the standard engine's values. Time-area values were duplicated in the prototype's cylinder according to the calculated value of TA rather than just copying the physical dimensions of the standard ports. By utilizing a spreadsheet, the geometry of the standard engine was duplicated mathematically by using the stock values of connecting rod length, piston stroke, and port heights. Since the ports are symmetrical with respect to the cylinder axis, they are open or closed an equal amount of time on either side of TDC or BDC. The spreadsheet enabled the area of the port window exposed by the piston to be calculated for every degree of crankshaft rotation. Summing the portions of the port area exposed between their opening and closing points provided the total area exposed during the interval of crankshaft rotation involving port exposure. In the standard engine, the exhaust port is fully open at only one position in the crankshaft rotation, which is BDC. Likewise, the intake port is fully open only at TDC. The standard engine upon which the inventive prototype engine is based is known as a ‘piston port’ engine. Intake and exhaust duration is controlled solely by the piston position in the cylinder bore, rather than by pressure differential, as would happen within a reed valve equipped engine during the intake phase (One other type of induction device is a disk with an hole in it, rotating in front of a port, which allows for unsymmetrical intake port timing and is known as a disk valve.)
[0041] Using a similar approach and a parallel spreadsheet to enable direct comparison, the piston position in the inventive prototype, relative to any angle of crankshaft rotation, was determined (Comparisons between the standard engine and the inventive prototype engine assume that the two crankshafts are rotating at the same RPM.) If the ports in the cylinder of the inventive prototype engine were left dimensionally the same as in the standard engine, the exhaust port would be uncovered much earlier than the standard engine's port. Since the piston in the inventive prototype engine dwells at the bottom of the cylinder bore for 43 degrees of crankshaft rotation, the exhaust port has no masking by the piston and remains fully open during this entire portion of crankshaft rotation. In comparison, the standard engine's exhaust port is fully open for only 9 degrees of crankshaft rotation. Since the piston dwells at the fully open position, the product of time and area combine to produce a TA value in excess of the original calculated value for the standard engine's ports. In the prototype, the width of the port is unchanged and only the height is adjusted. The original manufacturer of the engine chose the port widths with the considerations of piston ring support and wear, and these were maintained in the prototype. Since the TA value was too great, the height of the ports was lowered, which would cause two things to happen at once: The time portion of the TA value would fall since the port would be opened at a lower piston position and for a fewer number of degrees of crankshaft rotation, and the area portion of the TA value would fall as well, since the port was physically lower. Using the calculated values for piston position, it was possible to determine the combination of port height and number of crankshaft degrees that would duplicate the same TA values that were designed in the standard engine.
[0042] By lowering the port heights in a standard engine, more of the pressure and heat provided by the combustion of the fuel can be utilized to drive the piston downward, which increases the amount of work done on the piston every power phase. The trade-off is that the effective operating RPM range is lowered since the available TA values of the ports to scavenge the cylinder of exhaust gases and replace them with fresh fuel mixture is now shortened. A low RPM means that the number of power phases an engine can apply to the piston in a given time period is reduced, so the power output is diminished. On the other hand, port heights that are comparatively high mean more time is available to scavenge the cylinder, but the height of the port limits the trapped volume and mass of the fuel mixture entering the cylinder, which in turn limits the amount of work that can be done on the piston. Each power pulse is relatively weak, but the port can now support a greater amount of flow, which means that the engine can achieve a higher RPM. More power pulses are delivered to the crankshaft, and while individually weaker, their sheer numbers provide a higher output of horsepower.
[0043] The addition of the Epitrochoidal crankshaft as described in the present invention does not increase power by itself. What it allows is additional time to scavenge the cylinder if the port heights are left unchanged, which will increase the TA values of the ports at engine speeds identical to unmodified standard engines. This is accomplished by allowing the piston to travel to the lower portion of its travel at a rate faster than in a standard engine of equal stroke and operating at the same RPM. This alone will enable the Epitrochoidal crankshaft equipped engine to reach a higher RPM since the engine can still sufficiently scavenge the engine's cylinder at an elevated RPM. If the desired RPM range is to remain in the same realm as the unmodified standard engine, the Epitrochoidal crankshaft will cause the unmodified ports to have excessively large TA values. The simplest modification is to lower the ports, which will decrease the TA values of the ports and bring those values back into the original operating RPM range of the standard engine. However, lowering the ports now allows the piston to travel further with pressure acting upon it, which enhances the amount of work done on the piston during every power pulse. There will now be sufficient time to scavenge the engine's cylinder at the RPM range originally set by the stock engine, and power output will be enhanced due to the increased work done on the piston. Since the ports are fixed in their height and are now lower in the cylinder bore, the rising piston will cover the port windows and trap a larger volume of fuel mixture than the standard engine was capable of. As discussed earlier in this disclosure, the original actual CR in the standard engine was based upon the ratio of the total trapped volume of the fuel mixture compared to the fully compressed volume of the same. If the actual CR in the engine equipped with the Epitrochoidal crankshaft is to be preserved at the standard engine's value, additional volume must be added to the combustion chamber of the Epitrochoidal crankshaft equipped engine. Otherwise, the greater volume of the trapped fuel mixture would be compressed into the original combustion chamber volume, raising the actual CR to a value exceeding that of the standard engine. Adding combustion chamber volume reduces the actual CR to a value identical to the standard engine but will further add to the trapped volume. Again, an engine's power output is equated to the volume of the trapped fuel mixture during the power phase, so more power will be produced at engine speeds identical to the standard engine's RPM.
[0044] In an engine equipped with the Epitrochoidal crankshaft, the rapidly descending piston would create a large amount of momentum in the incoming fuel mixture, which would aid cylinder filling and fuel atomization. Upon entering the cylinder, the fuel mixture would not face the immediate pressure rise from a moving piston. Instead, the piston would remain at or near the bottom of the cylinder bore while the intake valve was closing. The result would be that a greater volume of fuel mixture would be trapped within the cylinder, resulting in more work being done on the piston for every power phase. Rather than having the cylinder fill to capacity only during an elevated engine speed, the motionless piston would allow a greater range of engine speeds where the cylinder would fill with the greatest efficiency. The fuel mixture quality would be enhanced due to the greater air-stream velocity through the fuel metering system, and better fuel atomization would result. The trapped mixture would tend to burn with greater efficiency within the combustion chamber, and the result would be a decrease in emissions of unburned fuel in the exhaust gases ultimately escaping into the atmosphere.
[0045] Two stroke cycle engines utilizing both ports and poppet valves can be made more fuel-efficient since the piston movement and position does not control the timing of the valves' opening and closing points. Instead, a camshaft actuates the valves. However, with the addition of an Epitrochoidal crankshaft, the piston is again made to dwell at the bottom of its stroke due to its quick descent within the cylinder bore. Again, the original port heights could be lowered without reducing the ports' TA values required for operation in the intended speed range, and the valve timing would be modified to complement the ports' TA values. The combination of lowering of the ports and delaying valve action means that more work can be done on the piston at the same RPM as the original engine. More of the heat and pressure created by the burning of the fuel would be utilized for pushing on the piston crown for each power phase while maintaining sufficient time to scavenge the cylinder.
[0046] Four stroke cycle engines utilizing the Epitrochoidal crankshaft can be made to be both more fuel efficient and more powerful. In this type of engine, there are no ports cut in the cylinder walls. Both intake and exhaust functions are controlled by poppet valves located in either the cylinder head (in valve-in-head engines) or the engine block (as in a flat-head or L-head design.) These valves rely instead on camshaft lobes to open and close them, and the valve motion is independent of the piston position and movement. If a similar Epitrochoidal path is followed by the lower end of the connecting rod as in the two stroke cycle versions previously discussed, the piston will fall within the cylinder bore faster than in a stock engine and will dwell near the bottom of the bore for some time. The engine equipped with the Epitrochoidal crankshaft can be made to ingest the same amount of fuel mixture as in a standard engine (or more, depending on camshaft selection, combustion chamber volume, and intended engine application), which would generate the same initial cylinder pressure, but the distance of piston movement with pressure above it (the power phase) would be increased. If so, this would increase the efficiency of the engine since more work would be done on the piston due to the non-symmetrical timing of the valve opening and closing events. The unique geometry caused by the Epitrochoidal crankshaft would cause the piston to be pushed down the bore at a faster rate and for a greater distance than would otherwise have been possible. Since the piston traveled further with the same initial starting pressure, more work will have been done on the piston, and the remaining pressure within the cylinder would be less at the time of the opening of the exhaust valve. A lower pressure escaping the cylinder would mean that the produced sound would be much less, so the exhaust note of the inventive engine would not be as great. While not a performance gain, the lower noise level would contribute less to noise pollution. Since sound is a form of energy, and that energy ultimately comes from the burning of the fuel, the lower exhaust tone would indicate a more efficient engine. The pressure in the standard cylinder would be greater at the end of the power phase since the piston would not have moved as far, and the opening exhaust valve allows useable cylinder pressure to escape without contributing to the power output.
[0047] In the four stroke cycle example of an engine equipped with the Epitrochoidal crankshaft, exhaust pressure that would normally be lost due to the standard engine's valve motion time constraints of evacuating the cylinder would be put to work forcing the piston further down the cylinder bore. Seldom mentioned in engine operation is the force required to open an exhaust valve against cylinder pressure. Cam lobes must initially overcome the spring pressure that is holding the valve on its seat before the valve moves. It is said that the work required compressing the spring is ‘given back’ to the system as the spring decompresses during valve closure. However, the surface area of the valve, combined with the pressure within the cylinder, must also be overcome before the valve will lift off of its seat. This additional force can be found when the area of the valve head is calculated and then multiplied by the cylinder pressure. As an example, an exhaust valve of only 1.00-inch diameter has a surface area of 0.785 square inches. If the pressure in the cylinder at the time of valve opening is 100 psi, the force required to open the valve is 78.5 pounds above that required to overcome the spring pressure. Since the exhaust gases leave the cylinder under their own pressure, no energy is returned to the system to recoup the force necessary to overcome the force against the valve head. This necessary force is subtracted from the net power output of the engine, and usable cylinder pressure is lost out of the exhaust tract. By holding the cylinder pressure within the cylinder and allowing it to further expand, as would be possible with the inventive engine, the loss in net power would be lower and the cylinder pressure would be more fully utilized. Once the pressure had dropped on its own during the dwell period, the piston would rise in the cylinder to sweep only residual gases out, rather than having to act on pressurized exhaust gases. There would be less negative work done on the piston, so the net gain would again be greater.
[0048] Since an engine equipped with the Epitrochoidal crankshaft allows a greater volume of fuel mixture to be ingested for each power phase, the engine's output will be greater. The enhanced cylinder filling occurs at all engine speeds, so horsepower and torque curves obtained from dynamometer testing will indicate an improvement throughout the entire RPM range. As an example, the two-stroke cycle inventive prototype engine traps approximately 15 percent more fuel mixture on every compression phase. This increased volume is due to the lowering of the exhaust port and the added volume in the cylinder head to maintain the original trapped CR of the standard engine. Since the exhaust port opens first and closes last in this engine, both the force and distance of the piston travel are enhanced and therefore produce more work on the piston. Comparing the horsepower and torque curves of the engine equipped with the Epitrochoidal crankshaft to the curves generated by a standard engine will reveal that the inventive engine's curves are similar in shape to the standard engine's curves, but elevated at all points by 15 percent. At the peak point on the standard engine's horsepower curve, the Epitrochoidal crankshaft equipped engine will produce 15 percent more power. Horsepower curves are typically ‘bell’ shaped, with the peak horsepower value occurring at the top of the bell. If the greatest amount of horsepower that the standard engine could produce were all that were desired, the inventive engine, having a similar but elevated power curve, would be required to rotate at a lower RPM in order to achieve that power output. At lower engine speeds, fuel consumption is reduced while the original power levels are maintained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is an exploded view of an Epitrochoidal crankshaft in a single crank wheel, overhung configuration.
[0050] FIG. 2 graphically depicts the circular path traveled by the center of the crankpin in a conventional engine.
[0051] FIG. 3 is a representation of the geometry of an eccentric bearing fitted within the lower end of a connecting rod.
[0052] FIG. 4 graphically depicts the path traveled by the center of the eccentric bearing in an engine with an Epitrochoidal crankshaft.
[0053] FIG. 5 is a representation of the curve defined by the on-centers length of a connecting rod.
[0054] FIG. 6 graphically depicts the path traveled by the center of the eccentric bearing having zero offset in a prototype engine with an Epitrochoidal crankshaft.
[0055] FIG. 7 graphically depicts the path traveled by the center of the eccentric bearing in a prototype engine with an Epitrochoidal crankshaft and 0.1334 inches of offset.
[0056] FIG. 8 graphically depicts the path traveled by the center of the eccentric bearing in a prototype engine with an Epitrochoidal crankshaft and excessive offset.
[0057] FIG. 9 is a representation of the differences in the curves defined by the on-centers length of a connecting rod on a prototype engine and the path traveled by the center of the eccentric bearing with excessive offset distance.
[0058] FIG. 10 is a representation of the curve defined by the on-centers length of a connecting rod on a prototype engine and the path traveled by the center of the eccentric bearing with correct offset distance.
[0059] FIG. 11 graphically depicts the relative location of two gears in an alternative Epitrochoidal crankshaft during 360-degrees of crankshaft rotation.
[0060] FIG. 12 graphically depicts the relative location of all elements in an alternative Epitrochoidal crankshaft during 360 degrees of crankshaft rotation.
[0061] FIG. 13 is a cross section of an alternative Epitrochoidal crankshaft.
[0062] FIG. 14 is an exploded view of an alternative Epitrochoidal crankshaft.
[0063] FIG. 15 is a cross section of a two-stroke cycle engine with piston at BDC showing alternative port positions.
[0064] FIG. 16 is a cross section of a two-stroke cycle engine with piston at TDC showing alternative port positions.
DETAILED DESCRIPTION OF THE INVENTION
[0065] One embodiment of the inventive Epitrochoidal crankshaft assembly, as depicted in the exploded view shown in FIG. 1 , is a simplified planetary gear system 1 utilizing a stationary sun gear 2 and a revolving planet gear 3 of equal pitch diameter. The two gears are kept in constant mesh by a crankshaft 4 that may also serve as a flywheel. The sun gear 2 is fixedly attached to the engine's crankcase, which is not shown, with its axis- 5 on the same rotational axis as that of the crankshaft 4 . The planet gear 3 is centered on the crankpin 6 by either a bushing or a bearing. These two gears each have a pitch diameter equal to the distance between the axis 5 of the crankshaft 4 and the axis of the crankpin 6 , or one-half the stroke of the crankshaft 4 . Since the gears are constantly in mesh, the distance between the centers of both gears will never vary; therefore, if the path of the axis 11 of planet gear 3 was plotted as it revolved around the stationary sun gear 2 , the resultant path would be circular and overlay the path of the axis of the crankpin 6 . An eccentric bearing 7 with an eccentric journal 7 a is mounted to the planet gear 3 and the center of the eccentric journal 7 a is axially offset from both the axis 11 of the planet gear 3 and the axis of the crankpin by a specific distance 8 . The lower end 10 of the connecting rod 9 having a lower end journal 10 a is fitted over the eccentric bearing 7 . Both the eccentric bearing 7 and the lower end 10 and lower end journal 10 a of connecting rod 9 having a lower end journal axis 10 b share a common center, which is offset from the crankpin 6 by the specific distance 8 . During the rotation of the crankshaft 4 , the stationary sun gear 2 will cause the planet gear 3 to rotate on its axis 11 , which is the same axis as that of the crankpin 6 . The eccentric bearing 7 , being attached solidly to the planet gear 3 , will be made to rotate on the axis of the crankpin 6 . Since the crankpin 6 itself is rotating with the crankshaft 4 , the planet gear 3 and eccentric bearing 7 will both be rotating around the crankpin 6 while it travels with the crankshaft 4 . Due to the combination of the crankshaft 4 and the stationary sun gear 2 , the planet gear 3 and the eccentric bearing 7 will rotate twice for every single rotation of the crankshaft 4 . The center of the eccentric bearing 7 will not follow the circular path of the crankpin 6 , but will trace an Epitrochoidal path. The axis 10 b of the lower end journal 10 a of the lower end 10 of the connecting rod 9 follows the center of the eccentric bearing 7 along this path as well. The Epitrochoidal shape will closely approximate a circle when the center of the eccentric bearing 7 is offset from the axis 11 of the planet gear 3 by a small amount and will assume a pronounced kidney shape as the center of the eccentric bearing 7 is offset away from the axis 11 of the planet gear 3 . The Epitrochoidal path generated by the stroke length and offset distance 8 produces a pattern that will reproduce itself with every rotation of the crankshaft 4 . The orientation of the pattern is achieved by aligning the offset distance 8 of the eccentric bearing 7 with a straight line drawn between the axis 5 of the crankshaft 4 and the axis of the crankpin 6 . The offset amount 8 will be pointed directly away from the crankshaft axis 5 so that the center of the eccentric bearing 7 is the maximum distance from the axis 5 of the crankshaft 4 . This position correlates to the TDC of the piston when the crankshaft 4 is at zero degrees of rotation. Such an arrangement will cause the Epitrochoidal pattern to have both a long moment arm in the upper portion of the pattern and a shorter moment arm along the bottom of the pattern. The lower portion of the pattern will have a large radius. The upper end 12 of the connecting rod 9 having an upper end journal 12 a with an upper end journal axis 12 b is pivotally connected to a piston which is not shown. The center-to-center length of the connecting rod 9 which is the distance between the upper end journal axis 12 b and the lower end journal axis 10 b must be chosen to match this large radius so that as the crankshaft 4 rotates, the lower end 10 of the connecting rod 9 will follow the Epitrochoidal path while the upper end 12 of the connecting rod 9 remains constrained along the cylinder centerline. The piston, being attached at the upper end 12 of the connecting rod 9 , will dwell at the bottom of its stroke for a considerable amount of crankshaft rotation. Since the inventive crankshaft involves the epitrochoid pattern, it is called an Epitrochoidal crankshaft.
[0066] In the development of the present invention, two engines were mathematically modeled. One was a commercially available conventional style engine and one was an engine equipped with the inventive Epitrochoidal crankshaft. Both engines have the same bore and stroke dimensions and therefore have the same displacement. The results indicate that the engine equipped with the Epitrochoidal crankshaft produces more power than the conventional engine at similar crankshaft speeds. Since horsepower is a function of the work performed on the piston and how often it occurs (the engine's RPM), the Epitrochoidal crankshaft equipped engine produces more horsepower due to the increased work done on the piston during the power phases at the same engine speed. This resulted in the modeled engine equipped with the inventive Epitrochoidal crankshaft producing 15 percent more total power, and 41 percent greater peak torque during each power phase than obtained from the standard engine. An inventive prototype engine containing the Epitrochoidal crankshaft has been built and run, based on a stock Homelite® two stroke cycle piston-port string grass trimmer engine with the following dimensions (inches, cubic inches, centimeters, and cubic centimeters are abbreviated “in,” “ci,” “cm,” and “cc” respectively):
Bore: 1.3125 in or 3.334 cm Stroke: 1.125 in or 2.858 cm Displacement: 1.52 cubic inches or 24.95 cc Exhaust port opens at 102 degrees past TDC: 0.749 in or 1.902 cm from TDC Transfer ports open at 128 degrees past TDC: 0.954 in or 2.423 cm from TDC Intake port closes at 60 degrees past TDC: 0.563 in or 1.430 cm from TDC Spark ignition occurs at 28 degrees before TDC: 0.082 in or 0.208 cm from TDC Combustion chamber volume of 0.1745 cubic inches or 2.86 cc's CR (measured full stroke): 9.72:1 CR (measured at exhaust port closing): 6.8:1 Connecting Rod length of 2.200 in or 5.588 cm
[0078] FIG. 2 is a graph that depicts the circular path 13 traveled by the center of the crankpin in a standard conventional engine during a complete 360-degree revolution. It also depicts the same circular path that the center of the crankpin travels in an engine equipped with an Epitrochoidal crankshaft. In the conventional engine from which the inventive prototype was modeled, the diameter of this circle is equal to the stroke length of 1.125 inches. The difference is that in a conventional engine, the circular path of the center of the crankpin is also the path of the center of the lower end of the connecting rod. In an engine equipped with an Epitrochoidal crankshaft, the circular path of the center of the crankpin is not the same as the path of the center of the lower end of the connecting rod. The center of the lower end of the connecting rod is located away from the center of the crankpin a distance equal to the offset distance provided by the eccentric bearing. FIG. 2 was plotted using the X and Y coordinates of the center of the crankpin for both a conventional and inventive engine where:
X=Stroke Length×Sine (Crankshaft Angle) and Y=Stroke Length×Cosine (Crankshaft Angle)
[0079] In FIG. 2 , the crankpin path is nothing more than a circle produced with the above formulae.
[0080] In all graphs depicting crankpin position, the X-axis is considered to be the horizontal axis and the Y-axis is considered to be the vertical axis. The cylinder centerline is assumed to be along the Y-axis, above the modeled crankshafts. Furthermore, rotation of all crankshafts modeled is assumed to be clockwise with TDC along the Y-axis at zero degrees of crankshaft rotation. BDC is located 180 degrees away from TDC along the Y-axis also. The origin of the X and Y coordinate system is considered to be the center of rotation of the modeled crankshafts.
[0081] FIG. 3 depicts the geometry of the eccentric bearing. The definition of the eccentric bearing is the bearing that fits within the lower end of the connecting rod. Its outer diameter 14 is equal to the inner diameter of the lower end journal of the connecting rod, minus a small clearance for the bearing and/or the lubricating oil wedge. The inside diameter 15 of the hole in the inner portion of the eccentric bearing is equal to the outside diameter of the crankpin, plus a small running clearance for the bearing and/or the lubricating oil wedge. The center of the outside diameter of the bearing is offset from the center of the inside hole of the eccentric bearing by a predetermined amount 16 . This is the offset that is referred to in the formula for the Epitrochoid pattern and was represented in FIG. 1 as the specific distance 8 . FIG. 4 represents the path 17 of the center of the lower end of the connecting rod in an engine equipped with an Epitrochoidal crankshaft. The center of the crankpin is a fixed distance from the center of the crankshaft and traces a circular path. In the case of the prototype engine, the crankpin circle has a radius of 0.5625 inches and therefore a diameter of 1.125 inches. Therefore, this is the measured stroke of the engine, or the vertical distance the piston travels in the cylinder. The inventive prototype engine used the stock crankshaft in its construction. The graph shown in FIG. 4 is produced as a result of the offset 16 of the eccentric bearing shown in FIG. 3 . The offset 16 is a calculated amount that results from the length of the connecting rod and the length of stroke desired in the prototype inventive engine. This calculated offset produces the large radius portion 18 of the pattern (near the bottom where the path runs within the stock stroke circle) and the extended area (at the top where the path runs outside the stock stroke circle.) By calculating an exact offset distance 16 , the piston is made to dwell at bottom dead center (BDC), or within 0.001 inches of BDC for a total of 43 degrees of crankshaft rotation in the modeled engine equipped with the inventive Epitrochoidal crankshaft.
[0082] Referring to FIG. 5 , the on-centers length 19 of the connecting rod 9 traces an arc 20 which closely matches and is approximately equivalent to the large radius portion 18 of the pattern shown in FIG. 4 . The wrist pin that attaches the connecting rod 9 and piston at the upper end 12 of the connecting rod 9 is also a pivotal bearing that allows the connecting rod 9 to deflect to either side of the cylinder centerline. If the piston is held stationary and the connecting rod 9 is allowed to swing back and forth, the center of the lower end 10 of the connecting rod 9 will swing in an arc 20 of radius equal to the on-centers length 19 of the connecting rod 9 . This is depicted in FIG. 5 .
[0083] This arc 20 is duplicated in the lower portion 18 of the pattern produced by the eccentric bearing and its offset distance 16 . The graph in FIG. 4 was plotted using the X and Y coordinates of the center of the eccentric bearing. This is also the path that the lower end 10 of the connecting rod 9 will follow. This is not the path of the crankpin, which is circular. The X and Y coordinates are expressed as follows:
X=[ ½ Stroke×Sine (Crank Angle)]−[Offset×Sine (2×Crankshaft Angle)]
Y=[ ½ Stroke×Cosine (Crank Angle)]−[Offset×Cosine (2×Crankshaft Angle)]
Where (in this example): Stroke=1.125 inches, Offset=0.1334 inches Crank Angle=Degrees of Crankshaft Rotation
[0086] This is a simplified version of the formulae for an epitrochoid, for which the inventive design is named.
[0087] The epitrochoid formulae for the X and Y coordinates are:
X = ( a + b ) Sine θ - ( c ) Sine ( a + b ) b θ and
Y = ( a + b ) Cosine θ - ( c ) Cosine ( a + b ) b θ
Where : a and b = radius of circle
c = offset distance
θ = angle of rotation
[0088] The inventive prototype engine is based on a conventional engine with a stroke of 1.125 inches and a bore of 1.3125 inches. The on-centers length of the stock connecting rod is 2.200 inches. This connecting rod length causes it to swing to a maximum deflection from the cylinder centerline, which will side load the piston against the cylinder bore. To properly compare the inventive prototype engine and conventional style engines, the prototype engine was built to have the same stroke and bore dimensions as the original engine. The stock piston and cylinder were used so that the bore would remain the same, and, when combined with the stock stroke length, would cause the inventive prototype engine to have the same displacement. In order for the inventive prototype engine to have the same deflection of the connecting rod, the inventive prototype engine required a connecting rod that was 3.000 inches, measured center to center.
[0089] The procedure used to determine connecting rod length and eccentric bearing offset may be illustrated by referring to FIG. 1 and assuming that the offset distance 8 of the eccentric bearing 7 from the axis of the crankpin 6 is zero inches. As the planet gear 3 revolves around the sun gear 2 during crankshaft rotation, the center of the eccentric bearing 7 will trace a circular path exactly on top of the path generated by the crankpin 6 . Since there is no offset of the eccentric bearing 7 , the lower end 10 of the connecting rod 9 will trace the same circular pattern and the piston position and motion will be unchanged from stock values. The vertical distance of the circular path along the cylinder centerline will be equal to the stroke of the crankshaft 4 . Assuming the planet gear 3 is on top of the sun gear 2 and that their centers are in line with the cylinder centerline and also that the centerline of the eccentric bearing 7 is also on the cylinder centerline, if the offset 8 of the eccentric bearing 7 is moved upward, away from the axis 5 of the crankshaft 4 by 0.001 inches, the resulting path of the center of the eccentric bearing 7 will no longer be circular. At TDC, the path will be 0.001 inches above the circular path of the crankpin 6 and 0.001 inches further away from the axis 5 of the crankshaft 4 . At BDC, the path will be 0.001 inches within the circular crankpin path and 0.001 inches closer to the axis 5 of the crankshaft 4 . The vertical distance of the newly generated path along the cylinder centerline will still be equal to the stroke of the crankshaft 4 and the piston will still travel 1.125 inches, as in the case of the prototype engine. As the offset 8 of the eccentric bearing 7 is moved further upward, the resulting path of the center of the eccentric bearing 7 will continue to increase in radius along the lower half of the pattern as the radius of curvature of the pattern increases in that area. Piston travel will continue to be unchanged at 1.125 inches. The goal is to continue to move the offset distance 8 upward until an eccentric bearing offset distance is found that produces a bottom portion of the pattern that matches and closely approximates an arc traced by a radius equal to the on-centers length 19 of the connecting rod 9 as depicted in FIG. 5 . FIGS. 6, 7 , and 8 demonstrate various offset distances 8 when applied to a crankshaft 4 with a desired 1.125-inch stroke. Since the amount of connecting rod deflection was chosen to equal the stock engine measurement, the optimum connecting rod length becomes 3.000 inches.
[0090] FIG. 6 illustrates the path 21 where the offset 8 is equal to zero. The resulting path is a circle equal to that of the path 13 of the crankpin 6 as shown in FIG. 2 for a conventional engine.
[0091] FIG. 7 illustrates the path 22 where the offset 8 is the correct amount of 0.1334 inches. The lower portion 18 of the resulting path is an arc described by a radius that matches the radius of the curve 20 equal to the on-centers length 19 of the connecting rod 9 as shown in FIG. 5 . The piston will tend to dwell within 0.001 inches of the BDC position for 43 degrees of crankshaft rotation.
[0092] FIG. 8 illustrates the path 23 where there is an excessive amount of offset 8 .
[0093] The final test of the offset and connecting rod distances is to observe the piston stroke not just at TDC and BDC but also during a complete crankshaft revolution. If the offset distance 8 is too great, the lower portion 18 of the path will have a radius greater than the radius produced by the connecting rod length 19 . This will cause the piston to reach its maximum lower travel before and after BDC, as measured at the crankshaft. The total distance that the piston would travel would now be greater than the allowed 1.125 inches even though the vertical distance along the cylinder centerline would remain 1.125 inches. If measured by the piston travel, BDC for the piston will occur at the two points of maximum piston travel, and the stroke of the piston will exceed 1.125 inches. These points will occur before and after BDC as measured by the crankshaft since the piston will have reached its point of lowest travel, traveled upward to crankshaft BDC, traveled back down to the second point of lowest travel, and then traveled back to the top of the cylinder bore to TDC. If the total distance of the piston travel were taken into account, the engine would have a displacement greater than was intended.
[0094] FIG. 9 depicts the path 23 produced by an eccentric bearing 7 with too great an offset distance 8 , superimposed on the depiction from FIG. 5 , showing the on-centers length 19 between the top end 12 and the bottom end 10 of the connecting rod 9 and the arc 20 generated with the on-centers length 19 as the radius. FIG. 10 depicts the path produced with a correct offset distance 8 , likewise superimposed on the depiction from FIG. 5 . When the offset distance 8 is correctly matched with the connecting rod length 19 , BDC is no longer a single point of maximum piston travel as it is in the stock engine but instead becomes a range of points, during which the piston remains virtually motionless. Piston dwell at or near BDC is increased, which is the desired effect.
[0095] Again, this orientation of the pattern was modeled in the prototype inventive engine. The values produced by this method for the prototype invention yields an offset distance of 0.1334 inches and a connecting rod length of 3.000 inches with a 1.125-inch stroke, as measured at both the crankshaft and the piston movement. In order to produce the optimum pattern for the connecting rod to follow for the prototype engine, the following dimensions were used (inches, cubic inches, centimeters, and cubic centimeters are abbreviated “in,” “ci,” “cm,” and “cc” respectively):
Bore: 1.3125 in or 3.334 cm Stroke: 1.125 in or 2.858 cm Displacement: 1.52 cubic inches or 24.95 cc Gear size (for both stationary and moving gear): 0.5625 in or 1.4288 cm pitch diameter Eccentric bearing offset: 0.1334 in or 0.3388 cm Connecting Rod length: 3.000 in or 7.620 cm Exhaust port opens at 87 degrees past TDC: 0.855 in or 2.172 cm from TDC Transfer ports open at 109 degrees past TDC: 1.018 in or 2.586 cm from TDC Intake port closes at 50 degrees past TDC: 0.4107 in or 1.043 cm from TDC Spark ignition occurs at 20.5 degrees before TDC: 0.082 in or 0.208 cm from TDC Combustion chamber volume of 0.1992 cubic inches or 3.264 cc's CR (measured full stroke): 8.6:1 CR (measured at exhaust port closing): 6.8:1
[0109] With reference to the path 17 depicted in FIG. 4 , the ignition point may be selected based on piston position, and without regard for actual crankshaft rotation. Piston position in the stock engine for spark timing is set to occur at 28 degrees BTDC, where the piston is located 0.082 inches away from the TDC position. The piston position at that point in crankshaft rotation is equal to the inventive prototype's piston position at 20.5 degrees BTDC.
[0110] Since the inventive design places the piston farther away from the crankshaft centerline at TDC than the standard engine, the moment arm is greater by the amount of eccentric bearing offset, which is 0.1334 inches. This longer moment arm results in increased piston speed, which lowers the piston toward the bottom of the cylinder bore faster. Torque curves modeled for the prototype engine show that the increased moment arm does produce a greater torque on the crankshaft while returning a lesser torque toward the end of the power stroke.
[0111] When comparing the motion of the piston in the epitrochoidal crankshaft equipped engine to that of the motion of a piston in a standard crankshaft equipped engine, the piston in the epitrochoidal crankshaft equipped engine has cylinder pressure above it for fewer degrees of crankshaft rotation. It would seem that the epitrochoidal crankshaft equipped engine couldn't produce a similar amount of power as the standard style engine. However, the actual distance of the piston movement per degree of crankshaft rotation in the epitrochoidal crankshaft equipped engine is greater than in a standard engine during the power phase. Comparing piston movement in the epitrochoidal crankshaft equipped engine to that of a piston from a standard crankshaft equipped engine, with both having the same stroke and same rate of crankshaft rotational speed (RPM), the piston from the epitrochoidal crankshaft equipped engine will travel further in the same amount of time than the piston from the standard crankshaft equipped engine. This is due to the increased moment arm length. Likewise, during the portion of crankshaft rotation when the moment arm is shorter, the piston will not travel as far. During the power phase, the rapid piston movement allows the piston to reach the bottom of the cylinder bore quicker than a conventional engine's piston. At or near the bottom of its travel, the crankshaft of the epitrochoidal crankshaft equipped engine is still turning at the same rate of rotational speed as the conventional engine, but the piston in the epitrochoidal crankshaft equipped engine is stopped. In the case of the inventive prototype engine, the piston is within 0.001 inches of its BDC position from 159 degrees of crankshaft rotation, past BDC, and until 201 degrees of crankshaft rotation. Since the piston travel is symmetric on either side of BDC, the total number of degrees of crankshaft rotation that the piston sits at or near BDC is 43. Conversely, the standard engine's piston is within 0.001 inches of BDC for a total of 9 degrees of crankshaft rotation.
[0112] An alternative proposed inventive prototype engine is based on the four stroke cycle Briggs & Stratton® 5 Horsepower horizontal shaft engine, common to tillers and lawn tractors. This engine was chosen for conversion to an epitrochoidal crankshaft equipped engine due to its simplicity of construction and availability. However, the inventive design is such that it can be adapted to all four stroke cycles engines, and this prototype engine serves as further proof of the Epitrochoidal crankshaft concept.
[0113] If timing of the phases of engine operation is to be controlled independently of piston motion, a camshaft is typically employed to operate intake and exhaust valves. The camshaft in a four-stroke cycle engine is geared to the rotation of the crankshaft, typically being driven at one half of the crankshaft speed. The cam lobes are designed to force the intake and exhaust valves open and can be fashioned to produce any desired valve motion, although it is the valves themselves that control the flow of gases through the intake or exhaust conduits. In the example that follows, the standard engine camshaft has been unaltered in both its lobe shape and in its timing of the valve events and is applied to both the standard and inventive prototype engine designs. Therefore, the timing and duration of the valve events is no different in either engine. In effect, the TA values that the camshaft produces in the intake and exhaust conduits are unaltered, since the duration of the valves being off their seats is the same in both the standard and inventive prototype engine. The standard engine's camshaft may not be the optimal cam design for the inventive prototype engine. However, the stock camshaft produces considerable power in the engine equipped with the Epitrochoidal crankshaft. The dimensions of the stock engine are as follows (inches, cubic inches, centimeters, and cubic centimeters are abbreviated “in,” “ci,” “cm,” and “cc” respectively):
Bore: 2.562 in or 6.507 cm Stroke: 2.438 in or 6.193 cm Displacement: 12.57 ci or 206 cc Exhaust valve opens at 130 degrees after TDC Intake valve closes at 75 degrees before TDC Spark ignition occurs at 28 degrees before TDC (piston position at 0.1852 in from TDC) Combustion chamber volume: 2.285 ci or 37.4 cc CR (measured full stroke): 6.5:1 Actual CR (measured by trapped intake volume): 3.45:1 Connecting Rod length of 3.875 in or 9.843 cm
[0124] As discussed earlier in the description of the inventive prototype two-stroke cycle engine, the CR that the manufacturer of the standard engine chose (6.5:1) is based on two factors—the actual displacement of the cylinder and the actual displacement of the combustion chamber. There is no mention of the actual volume of fuel mixture trapped within the cylinder during the compression phase. That volume is determined by the position of the piston at the time of the intake valve closing. Based on the valve timing listed above, the volume trapped in the cylinder is determined by the position of the piston at the time of the intake valve closing, which is 75 degrees of crankshaft rotation BTDC. The piston position is 1.0867 inches down in the cylinder at that time. In order to maintain the same CR in the inventive prototype engine, the trapped cylinder volume in the inventive prototype engine is figured in a similar manner, except that the cylinder head volume must be calculated so that the actual CR matches the same value as the original engine's CR. Since the stock camshaft and valve motion it produces are being employed, the piston in the inventive prototype engine is 1.634 inches down in the cylinder bore at the time of the intake valve closure. Therefore, to maintain the CR in the inventive prototype engine, the cylinder head volume in the inventive prototype engine must be increased. The actual trapped volume increases by the amount of additional cylinder bore gained, which means the prototype engine now ingests more fuel mixture during every intake phase. The inventive prototype engine traps more fuel mixture during every intake phase while still maintaining the same actual CR. Therefore, at all points within the original engine's intended RPM range, the inventive prototype engine will be ingesting more fuel mixture. As was described earlier in the discussion of the inventive prototype two-stroke cycle engine, the additional fuel mixture will result in raising the original torque and horsepower curves vertically, while still maintaining the original shape.
[0125] Since the CR in the stock engine was determined by the total stroke of the piston and the combustion chamber volume, the inventive prototype engine actually has a lower CR than the stock engine, if figured in the same manner. While it would seem that the inventive prototype engine would run poorly at such a low CR, it must be remembered that figuring the CR on full stroke displacement, rather than actual trapped volumes, can be misleading. If the cylinder head were left untouched in the inventive prototype engine, the CR would mathematically be identical to the stock engine's value since they would both be calculated based on total stroke. However, the actual CR would climb dramatically since a larger volume of fuel mixture would be forced into the original combustion-chamber volume. This new CR-would certainly increase the output of the inventive prototype engine (provided detonation did not occur) since the initial cylinder pressure would be greater and the resulting pressure curve would be increased, but that would introduce an undesirable advantage into the comparison. By maintaining the same initial cylinder pressure, a more reasonable comparison can be made that highlights the advantages produced by the addition of the Epitrochoidal Crankshaft.
[0126] Applying the same logic as was applied in the development of the two-stroke cycle inventive prototype; the four-stroke cycle inventive prototype would have the following dimensions (inches, cubic inches, centimeters, and cubic centimeters are abbreviated “in,” “ci,” “cm,” and “cc” respectively):
Bore: 2.562 in or 6.507 cm Stroke: 2.438 in or 6.193 cm Displacement: 12.57 ci or 206 cc Eccentric bearing offset: 0.2781 in or 0.7064 cm Exhaust valve opens at 130 degrees after TDC Intake valve closes at 75 degrees before TDC Spark ignition occurs at 20.2 degrees before TDC (piston position at 0.1852 in or 0.4704 cm down in bore) Combustion chamber volume: 3.43 ci or 56.21 cc's CR (measured full stroke): 4.66:1 Connecting Rod length of 4.2096 in or 10.69 cm Actual CR (measured by trapped intake volume): 3.45:1
[0138] Applying these dimensions to the produced pattern, and taking into account the increased intake volume, the inventive prototype engine now has a total torque output that is 35.8% greater than the original stock engine output.
[0139] During the power stroke in both the stock and inventive prototype engines, the location of the piston at the point of the opening of the exhaust valve makes an interesting comparison. In the stock engine, the piston is located 2.117 inches down in the bore, while the inventive prototype engine has its piston located at 2.381 inches down in the bore. The total stroke distance of both engine examples is 2.438 inches. In the stock engine, the piston travel with cylinder pressure acting on it amounts to 86.8% of the total stroke before the exhaust valve opens. In the inventive prototype engine, the piston travels 97.6% of the total stroke distance with pressure acting upon its top before the exhaust valve opens.
[0140] The first embodiment of the invention as generally depicted in FIG. 1 calls for two gears to be used. The use of this arrangement forces the crankshaft to assume a single crank wheel configuration, which is used for some small engines. In this configuration with an overhung load, support bearings are located on the same side of the crankshaft. However, this type of crankshaft is not conducive to multiple piston arrangements utilizing a single crankshaft. The moving gear in the inventive prototype must be free to rotate on the crankpin and mesh with the stationary gear as well. This prohibits having dual crank wheels on both sides of the crankpin, which would allow driving off of either end of the crankshaft or having multiple crankpins on the same crankshaft. The piston and the combustion pressures acting through it via the connecting rod dictate that the crankpin must be of sufficient diameter and strength to withstand those forces. At the same time, the moving gear must retain sufficient strength to transmit the rotational forces acting upon it, but as it is bored to accept the crankpin, the amount of material remaining between the crankpin and the root of the gear teeth is reduced, especially when a rolling element type of bearing is employed. One could not build an engine with a large diameter crankpin since the gear teeth strength would be compromised when the gear was bored to fit the crankpin.
[0141] However, there are alternative methods of generating an Epitrochoidal path that will allow the lower end of the connecting rod to move in the same manner as the original prototype two-gear design. A cross section of an alternative second embodiment is depicted in FIG. 13 and FIG. 14 illustrates an exploded perspective view of this second embodiment. Although the mechanical train is different, the same Epitrochoidal pattern is produced, and the theory behind the Epitrochoidal design remains the same. This second embodiment utilizes three gears. Two are conventional spur gears and the other is an internal toothed gear fixedly mounted to the crankcase. In order for the gearing to produce the desired pattern, the ratios between the gears' pitch diameters must be held to a 3 to 1 to 3 ratio. The stationary gear is the internal toothed gear 24 and is mounted such that its geometric axis 25 is the same as the axis of the crankshaft 29 —they share the same centerline. The internal toothed gear 24 must have three times the pitch diameter of the next gear in the train, the smaller spur gear 26 . Using the dimensions from the inventive prototype engine as an example, the internal toothed gear 24 has a pitch diameter of 1.6875 inches. The second gear 26 is a conventional spur gear with one-third the pitch diameter as the internal gear 24 , so it must have a pitch diameter of 0.5625 inches. Its pitch diameter is equal to one-half of the crankshaft's stroke, so in this example, the crankshaft stroke would be 1.125 inches, the same as the inventive prototype's stroke. The second gear 26 will be mounted such that its teeth will mesh with the internal toothed gear 24 . It will travel in a circular path within the internal gear 24 . Every revolution that its center travels around the central axis of the internal toothed gear 24 will cause it to rotate twice on its own axis.
[0142] FIG. 11 depicts two gears; the internal toothed gear 24 and the smaller spur gear 26 , and their relationship as the small gear 26 rotates and revolves within the internal toothed gear 24 . For clarity, the gear teeth are not shown. Rather, the pitch diameter is depicted. Also, a reference spot on the smaller spur gear 26 shows the position of the gear 26 at the various points of rotation. In this depiction, the smaller spur gear 26 is starting at the bottom of the internal toothed gear 24 and its reference spot begins on top of the smaller gear 26 . The gear's center will be traveling clockwise, which will cause the smaller spur gear 26 to rotate on its axis in a counter-clockwise manner within the internal toothed gear 24 . The motion of the reference spot also depicts that the smaller spur gear 26 rotates twice on its axis during a single revolution within the internal toothed gear 24 .
[0143] The third larger spur gear 27 must have a pitch diameter 3 times the size of the smaller spur gear 26 , so it must have a pitch diameter of 1.6875 inches. This larger spur gear 27 is of conventional gear design with its teeth on the outer circumference. Its geometric center will be the same as the axis 32 of the crankpin 31 . Since the internal toothed gear 24 and the larger spur gear 27 have the same pitch diameter, physical size demands the two gears be mounted in two parallel planes, with the smaller spur 26 gear meshed with both. Since these depictions are drawn on one plane, the internal toothed gear 24 in FIG. 12 is shown in a darker color to denote it is below the plane of both the smaller gear 26 and the larger spur gear 27 . To insure the gear train is kept intact, the small 0.5625 inch gear 26 discussed previously is actually two gears: One 26 a is meshed with the internal toothed gear 24 in the lower plane and the second 26 b is meshed with the larger spur gear 27 in the upper plane. The two smaller spur gears 26 a and 26 b are connected via a common shaft 26 c . The common shaft 26 c will be fixed in its location by mounting it in a bearing through one of the crank wheels 28 . Such an arrangement will keep the small gear 26 in mesh with both the internal toothed gear 24 and the larger spur gear 27 at all times. As the center of the larger spur gear 27 rotates around the central axis 25 of the crankshaft 29 in a clockwise direction, the smaller spur gear 26 , being in mesh with it, will cause the larger spur gear 27 to revolve in the same direction as its travel, which is depicted as clockwise. Note that the larger spur gear 27 rotates twice on its axis as its center travels once around the center 25 of the crankshaft. This motion is identical to the motion of the moving planet gear 3 in the first embodiment of the prototype inventive engine shown in FIG. 1 . The larger spur gear 27 is attached to an eccentric bearing 30 in a manner similar to the first embodiment. Since the gear's diameter is much larger than in the first embodiment, the crankpin 31 can be a relatively large diameter, which can increase the load bearing area for the bearings. This diameter will not cause the crankpin 31 to be marginal in size, nor will the gear 27 have marginal material below the gear teeth roots. The gear 27 will still rotate in the same manner as in the first embodiment, and the offset distance 8 associated with the eccentric bearing 30 will be identical to the original calculation.
[0144] In FIG. 12 , all components needed to generate the epitrochoid pattern are displayed. The crankshaft crank wheels 28 , which would locate the centers of the gears in bearings, have not been depicted so that the relationship of the components that generate the epitrochoid pattern can be seen as they interact.
[0145] FIG. 15 depicts a two stroke cycle engine 33 with cylindrical housing 39 with fixed ports while the piston 34 is located at BDC, and FIG. 16 depicts a two stroke cycle engine 33 with fixed ports while the piston 34 is located at TDC. These figures depict the differences in the standard engine's exhaust ports 35 , intake ports 36 , and transfer ports 37 . As shown, the height 35 a of the exhaust ports 35 and height 37 a of the transfer ports 37 in the standard engine are lowered to height 35 b and 37 b in the prototype inventive engine to maintain the proper TA values in their respective tracts, and height 36 a of the intake port tract 36 in the standard engine is raised to height 36 b in the prototype engine. These differences in height are caused by the different speeds of the piston 34 during its travel within the cylinder, and the enhanced dwell period. Since the piston 34 is moving faster in the upper reaches of the cylinder, the available time for the intake port 36 is reduced and therefore requires more area to achieve the proper TA figure. On the other hand, the exhaust ports 35 and transfer ports 37 can be lowered since the piston 34 dwells at or near BDC. The lower port window is necessary for the TA value of the port to be maintained, but this aspect also provides a larger fuel mixture volume to be trapped in the cylinder during the next compression and power phase. Since more fuel mixture is trapped, the cylinder head volume must be increased to maintain the original CR. The cylinder head 38 must be enlarged from the chamber outline 38 a for a standard engine to the outline 38 b for the prototype engine to acquire the increased volume necessary, which also adds to the total volume of the trapped mixture charge.
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This invention relates to a mechanism and method for enhancing the performance of both two stroke and four stroke cycle reciprocating piston internal combustion engines, reciprocating piston pumps and compressors by generating an Epitrochoidal path of travel for the lower end of the connecting rod. The piston, attached to the upper end of the connecting rod, will be made to dwell at the lower part of its travel, enhancing the output of the engine, pump or compressor through better utilization of the available cylinder pressure.
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RELATED APPLICATIONS
[0001] This application is a Division of U.S. application Ser. No. 10/688,690 filed on Oct. 17, 2003, which is incorporated herein by reference in it entirety.
BACKGROUND OF THE INVENTION
[0002] Minimally, optical spectroscopy systems typically comprise a source for illuminating a target, such as a material sample, and a detector for detecting the light from the target. Further, some mechanism is required that enables the resolution of the spectrum of the light from target. This functionality is typically provided by a spectrally dispersive element.
[0003] One strategy uses a combination of a broadband source, detector array, and grating dispersive element. The broadband source illuminates the target in the spectral scan band, and the signal from the target is spatially dispersed using the grating, and then detected by an array of detectors.
[0004] The use of the grating, however, requires that the spectroscopy system designer make tradeoffs. In order to increase the spectral resolution of these systems, aperturing has to be applied to the light provided to the grating. As more spectral resolution is required, more light is required to be rejected by the narrowing spatial filter. This problem makes this strategy inappropriate for applications requiring a high degree of spectral precision combined with sensitivity.
[0005] Another approach is to use a tunable narrowband source and a simple detector. A typical approach relies on a tunable laser, which is scanned over the scan band. By monitoring the magnitude of the tunable laser's signal at the detector, the spectrum of the sample is resolved. These systems have typically been complex and often had limited wavelength scanning ranges, however.
[0006] Still another approach uses light emitting diodes (LEDs) and an acousto-optic modulator (AOM) tunable filter. One specific example combines multiple light emitting diodes (LEDs) in an array, each LED operating at a different wavelength. This yields a relatively uniform spectrum over a relatively large scan band. The light from the diodes is then sent through the AOM tunable filter, in order to create the tunable optical signal.
[0007] The advantage of this system is the use of the robust LED array. This provides advantages over previous systems that used other broadband sources, such as incandescent lamps, which had limited operating lifetimes and high power consumption.
[0008] While representing an advance over the previous technology, the disadvantages associated with this prior art system were related to the use of the AOMs, which are relatively large devices with concomitantly large power consumptions. Moreover, AOMs can also be highly temperature sensitive and prone to resonances that distort or alter the spectral behavior, since they combine a crystal with a radio frequency source, which establishes the standing wave in the crystal material to effect the spectral filtering.
[0009] Grating-based spectrometers also tend to be large devices. The device packages must accommodate the spatially dispersed signal from the sample. Further, the interface between the grating and the detector array must also be highly mechanically stable. Moreover, these grating based systems can be expensive because of costs associated with the detector arrays or slow if mechanical scanning of the detector or grating is used.
SUMMARY OF THE INVENTION
[0010] The drawbacks associated with the prior art spectrometers arise from the large size of the devices combined with the high cost to manufacture these devices combined with poor mechanical stability. These factors limit the deployment of spectrometers to applications that can justify the investment required to purchase these devices and further accommodate their physical size.
[0011] Accordingly, the present invention is directed to an integrated spectrometer system. Specifically, it is directed to the integration of a tunable Fabry-Perot system with a source system and/or detector system. The use of the Fabry-Perot filter system allows for a high performance, low cost device. The integration of the filter system with the source system and/or detector system results in a device with a small footprint. Further, in the preferred embodiment, the filter system is based on microelectromechancial systems (MEMS), which yield a highly mechanically robust system.
[0012] In general, according to one aspect, the invention features a spectroscopy system. The system comprises a source system for generating light to illuminate a target, such as a fiber grating or a material sample. A tunable Fabry-Perot filter system is provided for filtering light generated by the source. A detector system is provided for detecting light filtered by the tunable filter from the target. According to the invention, at least two of the source system, tunable Fabry-Perot filter system, and the detector system are integrated together.
[0013] Specifically, in one embodiment, the source system and tunable Fabry-Perot system are integrated together on a common substrate, such as an optical bench, also sometimes called a submount. In another embodiment, the tunable Fabry-Perot filter system and the detector system are integrated together on a common substrate, such as an optical bench. Finally, in still another implementation, all three of the source system, tunable Fabry-Perot filter system, and the detector system are integrated together on a common bench, and possibly even in a common hermetic package.
[0014] Temperature control is preferably provided for the system. Currently this is provided by a heater, which holds the temperature of the system above an ambient temperature, or a thermoelectric cooler. For example, the thermoelectric cooler is located between the bench and the package to control the temperature of the source system, tunable Fabry-Perot filter system, and/or the detector system. As a result, a single cooler is used to control the temperature of the filter and SLED chip, lowering power consumption, decreasing size, while increasing stability.
[0015] In the preferred embodiment, the source system comprises a broadband source. This can be implemented using multiple, spectrally multiplexed diode chips. Preferably, superluminescent light-emitting diodes (SLEDs) are used. These devices have a number of advantages relative to other sources, such incandescent sources. Specifically, they have better spectral brightness, longer operating lifetimes, and a smaller form factor.
[0016] In order to increase the spectral accuracy of the system, a tap can also be used to direct a part of the tunable signal to a detector. A spectral reference, such as a fixed etalon with multiple spectral transmission peaks is placed between the detector and the tap, in order to create a fringe pattern on the detector during the scan, thereby enabling monitoring of the wavelength of the tunable signal. An optical power tap can also be included to monitor the real time emitted optical power during the scan.
[0017] The tunable Fabry-Perot filter system comprises single or multiple filters. In one example, multiple serial filters are used. In another embodiment, multiple parallel filters are used.
[0018] In still further embodiments, multiple detectors can be used. These detectors can be responsive to different wavelengths or a calibration signal.
[0019] In the preferred embodiment, in order to make the system small, compact and highly robust, a micro-electro-mechanical system (MEMS) Fabry-Perot tunable filter is used. These devices can achieve high spectral resolutions in a very small footprint.
[0020] Finally, in the preferred embodiment, isolation is provided between the source system and the tunable Fabry-Perot filter system. This prevents back reflections from the filter into the source system that can disturb the operation of the source system. In one example, an isolator is installed on the optical bench between the SLED and the tunable filter. A quarter wave plate can also be used. This rotates the polarization of the returning light so that it is not amplified by the highly polarization anisotropic SLED gain medium. In another embodiment, the isolation is provided on the bench, with the tunable Fabry-Perot filter system and the detector system.
[0021] The present invention is also directed to an integrated tunable source that combines a broadband source and a tunable filter, such as a tunable Fabry-Perot filter, although other tunable filters could be used in this configuration. Applications for this device extend beyond spectroscopy.
[0022] Between the tunable filter and the light source, isolation is preferably provided. This stops back reflections from the tunable filter into the diode, which could impact its performance. Isolation can be achieved using a number of techniques. In one embodiment, a discrete isolator is used. In another embodiment, when a SLED is used as the source, a quarterwave plate is used between the SLED chip and the filter. Finally, a flat-flat cavity Fabry-Perot tunable filter is used in still another embodiment, with isolation being accomplished by tilting the filter relative to the SLED.
[0023] A variety of other light sources can be used, including LEDs, doped fiber or waveguide amplified spontaneous emission sources, and thermal sources.
[0024] According to still another aspect, the invention features a high power tunable source. This addresses one of the primary drawbacks associated with the use of a broadband source and tunable filter configuration, namely their usually low output power. Specifically, an optical amplifier is further added in order to increase the power of the tunable signal. As a result, power levels comparable to those attainable with tunable lasers can be achieved in this configuration.
[0025] In a typical implementation, the amplifier is a semiconductor optical amplifier (SOA). In other examples, various types of fiber amplifiers are used, however.
[0026] The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
[0027] The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:
[0029] FIGS. 1A and 1B illustrate embodiments of the integrated spectroscopy system according to the present invention;
[0030] FIG. 2 is a perspective view showing a tunable source, according to the present invention, and including a detector system for detecting the tunable signal from the sample;
[0031] FIG. 3A is a perspective view of the MEMS Fabry Perot tunable filter, used in embodiments of the present invention, which is compatible with tombstone mounting on the optical bench;
[0032] FIG. 3B is an exploded view of the inventive Fabry Perot tunable filter;
[0033] FIG. 4 is a perspective view showing an amplified tunable source, according to the present invention, in a hermetic package;
[0034] FIG. 5 is a perspective view showing a reference detector embodiment of a tunable source, according to the present invention, in a hermetic package;
[0035] FIG. 6 is a block diagram of an embodiment of the tunable source with both a wavelength and power reference detector;
[0036] FIG. 7 is a perspective view showing still another embodiment of a tunable source, according to the present invention, using two SLED chips;
[0037] FIG. 8 is a perspective view showing a further embodiment of a tunable source, according to the present invention using multiple SLED chips and tunable filters;
[0038] FIG. 9 is a perspective view showing another embodiment of a tunable source, according to the present invention, using parallel filters and multiple SLED sources;
[0039] FIG. 10 is a perspective view showing a further embodiment of a tunable source, according to the present invention, using serial filters;
[0040] FIG. 11 is a plot of wavelength as a function of transmission showing the relationship between the free spectral ranges of the serial filters, in one embodiment;
[0041] FIG. 12A is a perspective view of a tunable detector spectroscopy system, according to the present invention;
[0042] FIG. 12B is a perspective view of another embodiment of a tunable detector spectroscopy system, according to the present invention;
[0043] FIG. 13 is a perspective view of still another embodiment of a tunable detector spectroscopy system, according to the present invention, using multiple parallel filters; and
[0044] FIGS. 14 and 15 show two fully integrated spectroscopy systems in which a tunable source and a detector system are integrated on the same bench.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] FIGS. 1A and 1B illustrate an integrated spectroscopy system 1 , which has been constructed according to the principles of the present invention.
[0046] Specifically, FIG. 1A shows two alternative integration configurations.
[0047] According to configuration 1 , a source system 100 is provided. This is a broadband source, which generates light 40 for illuminating a target, such as sample S- 1 or a fiber grating, for example. This target selectively absorbs and/or scatters the light from the source system 100 . The transmitted light is then received by a tunable Fabry-Perot filter system 200 . This functions as a narrow band tunable spectral filter. It tunes its passband over the scan band within the spectral band of the source system 100 . As a result, it resolves the spectrum of the target S- 1 into a time response. This time-resolved signal is then detected by detector system 300 .
[0048] According to the integration provided by this configuration 1 , the tunable Fabry-Perot filter system 200 and the detector system 300 are integrated together. Specifically, in the preferred embodiment, the tunable Fabry-Perot filter system 200 and the detector system 300 are installed on a common bench B- 1 . Moreover, in the current embodiment, the tunable Fabry-Perot filter system 200 and the detector system 300 are integrated together on the common bench B- 1 in a common hermetic package.
[0049] The integration of the Fabry-Perot filter system 200 , with the detector system 300 on the common bench B- 1 , yields the tunable detector 20 which is characteristic of the configuration 1 integration.
[0050] FIG. 1A also illustrates a second configuration, configuration 2 integration. In this second configuration, the source system 100 and the tunable Fabry-Perot system 200 are integrated together. In the preferred embodiment, they are installed together on a common bench B- 2 . Further, in the current implementation, the source system 100 and the tunable Fabry-Perot filter system are integrated together on the common bench B- 2 and installed in a common hermetic package to yield a tunable source 10 . This tunable source 10 generates a tunable signal 30 , which is used to illuminate a target, located in this second configuration at position S- 2 . The target either scatters or absorbs spectral components of the tunable signal as it is scanned across the scan band. This allows the detector system 300 to resolve the time varying signal as the spectral response of the target S- 2 .
[0051] FIG. 1B illustrates a fully integrated system according to still another embodiment. Here, the source system 100 , the tunable Fabry-Perot filter system 200 , and the detector system 300 are integrated together. Specifically, in the preferred embodiment, they are integrated together and installed on a common bench B. This bench B is preferably located in a hermetic package.
[0052] Depending on whether the tunable source system 100 , the Fabry-Perot filter system 200 , and detector system 300 , are combined as a tunable source 10 or tunable detector 20 , the target is located either in position S- 1 or S- 2 . Specifically, in the implementation of a tunable source 10 with the source system 100 and the tunable Fabry-Perot filter system 200 functioning to create a tunable signal, the tunable signal 30 is coupled outside of the hermetic package and off of the bench B to the target S- 2 , in the case of configuration 2 . Alternatively, if the tunable Fabry-Perot filter system 200 and the detector system 300 function to yield the tunable detector 20 , then the broadband signal 40 from the source system 100 is coupled off of the bench and the outside of the hermetic package to the target S- 1 in the case of the first configuration.
[0053] FIG. 2 illustrates a first embodiment of the tunable source 10 . Specifically, in this embodiment, the bench B- 2 holds the tunable Fabry-Perot filter system 200 and the source system 100 on a common planar surface. The generated tunable signal 30 is coupled off of the bench B- 2 by an optical fiber 102 . In the preferred embodiment, this optical fiber 102 is a single transverse mode fiber. This has advantages in that it renders the tunable signal 30 very stable, even in the event of mechanical shock to the single mode fiber 102 .
[0054] The source system 100 is implemented using, in this embodiment, a superluminescent light emitting diode (SLED) 110 . The diode 110 is installed on a submount 112 . The submount 112 is, in turn, installed on the bench B- 2 . In the preferred embodiment, the SLED chip 110 is solder bonded to the submount 112 , which further includes metallizations 114 to facilitate wire bonding to provide electrical power to the SLED chip 110 . Further, the submount 112 is solder bonded to the bench B- 2 , which in turn, has metallizations 115 to enable formation of the solder bonds.
[0055] These SLEDs are relatively new, commercially-available devices and are sold by Covega Corporation, for example, (product numbers SLED 1003, 1005, 1006). These devices are currently available in wavelength ranges from 1,200 nanometers (nm) to 1,700 nm from a variety of vendors. They are waveguide chip devices with long gain mediums similar to semiconductor optical amplifiers. An important characteristic is their high spectral brightness.
[0056] The broadband signal 40 that is generated by the SLED chip is collimated by a first lens component 114 . This lens component 114 comprises a lens substrate 117 , which is mounted onto a deformable mounting structure 118 . The deformable mounting structure is preferably as those structures described in U.S. Pat. No. 6,559,464 B1 to Flanders, et al., which is incorporated herein in its entirety by this reference. The alignment structure system allows for post installation alignment by mechanical deformation of the mounting structure 118 of the lens substrate 117 .
[0057] The collimated light from the first lens component 114 in the preferred embodiment is coupled through an isolation system, such as an isolator 120 or quarterwave plate. The beam from the isolator is then collimated by a second lens element 122 and coupled into the Fabry-Perot tunable filter system 200 . The isolator system prevents all back reflections or back reflections that have a polarization that is aligned with the gain polarization of the SLED chip 110 . These reflections arise from the Fabry-Perot filter system 200 . This isolation promotes the stability in the operation of the SLED chip 110 .
[0058] In the preferred embodiment, the tunable filter system 200 is implemented as a MEMS tunable Fabry-Perot filter 116 . This allows for single transverse mode spectral filtering of the broadband light 40 from the SLED chip 110 , yielding the tunable signal 30 . Tunable signal 30 is coupled into the endface 104 of the single mode optical fiber 102 . In the current embodiment, the endface 104 of the optical fiber 102 is held in alignment with the MEMS tunable filter 116 , via a fiber mounting structure 106 . Again, this allows for post installation alignment of the fiber endface 104 to maximize coupling of the tunable signal 30 , into the single mode fiber 102 . The fiber 102 transmits the tunable signal 30 to target S- 2 and then, the response is detected by detector system 300 .
[0059] Depending on the embodiment, the Fabry-Perot filter 116 has either a curved-flat cavity or a flat-flat cavity. The curved flat cavity increases angular tolerance between the two mirrors of the Fabry-Perot filter. The flat-flat cavity provides better single mode operation. Moreover, there is the option to avoid the necessity for discrete isolators or waveplates by angle isolating the filter for the source system 100 .
[0060] FIG. 3A is a close up view of the tunable filter 116 . The tunable filter 116 comprises a MEMS die 410 . This has a number of wire bond locations 412 for making electrical connection to the MEMS die 410 . A MEMS die 410 provides the moveable mirror portion or component of the tunable filter. A fixed mirror portion or component 414 is bonded to the MEMS die 410 in order to define the Fabry Perot cavity. In one embodiment, the fixed mirror component provides the flat mirror and the MEMS die 410 provides the curved mirror.
[0061] In the preferred embodiment, the tunable filter 116 is “tombstone” mounted onto the bench B, B- 1 , B- 2 . Specifically, the fixed mirror substrate 414 extends down below the bottom of the MEMS die 416 by a distance L. Specifically, the fixed mirror substrate has a bottom surface 418 that serves as a foot that is bonded to the bench. Preferably, a layer of solder 420 is used to attach the fixed mirror substrate 414 to the bench B. In the preferred embodiment, the distance L is approximately 1-10 micrometers.
[0062] FIG. 3B is an exploded view of the tunable filter 116 . This shows the fixed mirror substrate 414 disconnected from the MEMS die 410 . Flexures 421 define a MEMS membrane 423 . The deflectable membrane 423 holds the mirror layer 424 of the tunable mirror and covers a depression 425 formed in the membrane 423 that forms the curved mirror of one embodiment. Metallization pads 426 are provided on the MEMS die 410 in order to solder attach the fixed mirror substrate 414 to the MEMS die 410 .
[0063] The general construction of this tunable filter is described in, for example, U.S. patent application Ser. No. 09/734,420, filed on Dec. 11, 2000 (now Publication No. U.S. 2002-0018385). This application is incorporated herein, in its entirety by this reference.
[0064] FIG. 4 illustrates another embodiment of the tunable source 10 . In this embodiment, the broadband signal generated by the SLED chip 110 is again coupled through a first lens component 114 to an isolator 120 . A second lens component 122 is further provided for coupling the broadband signal into the filter 116 of the Fabry-Perot filter system 200 .
[0065] Then, a third lens component 126 is provided to couple the tunable optical signal 30 into a semiconductor optical amplifier 128 . In the preferred embodiment, this semiconductor optical amplifier chip 128 is installed on an amplifier sub-mount 130 , which is installed on the bench B- 2 . The amplified tunable optical signal generated by the semiconductor optical amplifier chip 128 is then coupled into the endface 104 of the optical fiber 102 to be coupled out of the hermetic package 132 . This allows the tunable signal 30 to be coupled, in an amplified state, to the target S- 2 followed by detection by the detector system 300 .
[0066] In some other embodiments additional isolators are located between the fiber endface 104 and the amplifier chip 128 and between the amplifier chip 128 and the third lens component 126 .
[0067] In the preferred embodiment, the hermetic package 132 is a standard telecommunications hermetic package. Specifically, it comprises a standard butterfly package. The lid 136 is shown cut away to illustrate the internal components. Further, the optical bench B- 2 is preferably installed on a thermoelectric cooler 134 , which enables a controlled environmental temperature to stabilize the operation of the SLED chip 110 and the tunable Fabry-Perot filter system 200 .
[0068] Electrical leads 138 are further provided to transmit electrical signals to the pads 146 on the inside of the hermetic package 132 . Wire bond are made between pads 146 and the active components such as the SLED chip 110 , MEMS tunable filter 116 , and SOA 128 .
[0069] The FIG. 4 embodiment has the advantage that the tunable signal 30 received from the tunable Fabry-Perot filter system 200 is amplified to further increase the dynamic range and the signal-to-noise ratio of the spectroscopy system.
[0070] In the embodiment of FIG. 5 , the tunable source 10 also combines a SLED chip 110 , a first lens component 114 , isolator 120 , and a second lens component 122 . This launches the broadband signal 40 from the SLED chip into the tunable filter system 200 . A third lens component 126 is further provided. This collimates the beam. A splitter, however, comprising a partially reflective substrate 149 , provides a portion of the tunable signal 30 to a detector 140 . This detector 140 can be used to monitor the magnitude or power in the tunable signal 30 . In another embodiment, a reference substrate 148 is installed between the detector 140 and the tap 149 . This reference substrate 148 provides stable spectral features. In one embodiment, this is provided by a fixed etalon substrate. A controller monitoring the output of the detector 140 compares the tunable signal to the spectral features of the reference substrate 148 to thereby resolve the instantaneous wavelength of the tunable signal 30 .
[0071] In still other embodiments, instead of a reference substrate, a gas cell is used as the spectral reference for calibrating the scan of the tunable filter 116 . Also two splitters can be included to provide simultaneous spectral and power references.
[0072] The tunable signal, which is not coupled to the detector 140 by the tap 149 is launched by a fourth lens component 147 into the fiber endface 104 of the optical fiber 102 .
[0073] FIG. 6 illustrates the general operation provided by a controller 150 of the tunable source 10 . Specifically, the controller 150 is used to control the power or current supplied to the SLED chip 110 . Its broadband signal 40 is coupled to the isolator 120 . The controller also controls the tunable pass band of the tunable filter system 200 to generate the tunable signal 30 .
[0074] In the case of monitoring the frequency of the tunable signal, a first tap 149 couples a portion of the tunable signal to a spectral reference 148 , which in the illustrated embodiment, is a fixed etalon. This allows the detector 140 to detect the wavelength of the tunable signal 30 during the scan.
[0075] In the preferred embodiment, a power detector 154 is also provided. This is added to the optical train using second tap 152 , which again couples the portion of the tunable signal 30 to a power detector 154 . The controller 150 controls and monitors the wavelength detector 140 and the power detector 154 to determine both the wavelength and the power in the tunable signal 30 .
[0076] FIG. 7 illustrates another embodiment of the tunable source 10 . This embodiment is used either to increase the power or the spectral width of the scan band of the tunable source 10 . Specifically, multiple SLED chips, and specifically two SLED chips 110 A and 110 B, are installed together on the optical bench B- 2 . In the illustrated embodiment, the SLED chips 110 A and 110 B are installed on a common sub-mount 112 , which is in turn, bonded to the bench B- 2 .
[0077] Two first lens components 118 A, 118 B are provided to couple the broadband signals from their respective SLED chips 110 A, 110 B and collimate those beams. A combination of a fold mirror 156 and a combiner 158 are provided to combine the broadband signals from each of these SLED chips 110 A, 110 B into a single broadband signal, which is coupled through the isolator 120 .
[0078] The beam from the isolator 120 is then focused by a second lens component 122 into the tunable filter 200 . A third lens component 126 then couples the tunable signal into the optical fiber 102 via the endface 104 .
[0079] In the high power version of the FIG. 7 embodiment, a polarization rotator, such as a quarterwave plate 160 is provided in the beam path of one of the SLED chips 110 A, 110 B. In the illustrated embodiment, this polarization rotator 160 is provided in the beam path of the second SLED chip 110 . This rotates the polarization of the light from the second SLED chip 110 B by 90°. Then, the combiner 158 is a polarization combiner that is transmissive to the polarization of the light from the first SLED chip 110 A, but reflective to the polarization of light from the second SLED chip 110 B. As a result, the beams from each of the SLED chips 110 A, 110 B are merged into a common broadband signal with increased power.
[0080] In a second implementation of the FIG. 7 embodiment, the SLED chips 110 A, 110 B operate at different spectral bands. Specifically, SLED chip 110 A generates light in a scan band A and SLED chip 110 B generates light in an adjacent but different scan band B. The combiner 158 is a wavelength division multiplex combiner that is configured to be transmissive to the band of light generated by the SLED chip 110 A, but reflective to light in the band generated by SLED chip 110 B. As a result, the combined signal generated together by the SLED chip 110 A, 110 B has a broader scanband then could be generated by each of the SLED chips individually. This allows for increased bandwidth in the tunable signal 30 that is generated by the tunable source 10 .
[0081] FIG. 8 illustrates another embodiment of the tunable source 10 . This embodiment uses a tunable filter system 200 , which includes an array of tunable filters 116 and broadband light sources in order to increase the spectral width of the scanband. Typically, and in the illustrated embodiment, an array of five SLED chips 110 are mounted in common on the bench B- 2 . The light from each of these SLED chips 110 is collimated by respective first lens components 118 . Specifically, there is a separate lens component 118 for each of these SLED chips 110 . Separate isolators 120 are then provided for the broadband signals from each of the SLED chips 110 .
[0082] An array of second lens components 122 is further provided to couple the broadband signal into an array of tunable filters 200 . Specifically, separate Fabry-Perot tunable filters 116 are used to filter the signal from each of the respective SLED chips 110 . Finally, an array of third lens components 126 is used to re-collimate the beam from the tunable Fabry-Perot filters 116 of the tunable filter system 200 .
[0083] For channel 1 , C- 1 , a fold mirror 156 is used to redirect the beam from the SLED chip 110 . The WDM filter 160 is used to combine the broadband signal from the SLED chip 110 of channel C- 2 with the signal from channel C- 1 . Specifically, the filter 160 is reflective to the wavelength range generated by the SLED chip 110 of channel C- 2 , but transmissive to the wavelength range of light generated by the SLED chip 110 of channel C- 1 .
[0084] In a similar vein, WDM filter 162 is reflective to the signal band generated by the SLED chip 110 of channel C- 3 , but transmissive to the bands generated by SLED chips 110 of channels C- 1 and C- 2 . WDM filter 164 is reflective to the light generated by SLED chip 110 of channel C- 4 , but transmissive to the bands generated by the SLED chips 110 of channels C- 1 , C- 2 , and C- 3 . Finally, WDM filter 158 is reflective to all of the SLED chips, but the SLED chip 110 of channel C- 5 . As a result, the light from the array of SLED chips is combined into a single broad band tunable signal 30 .
[0085] A first tap 149 is provided to reflect a portion of the light through the etalon 148 to be detected by the wavelength detector 140 . Then, another portion is reflected by tap 152 to the power detector 154 . The remaining tunable signal is coupled by the fourth lens component 106 into the optical fiber 102 via the endface 104 .
[0086] The FIG. 8 embodiment can operate according to a number of different modes via a controller 150 . Specifically, in one example, only one of the SLED chips in channels C- 1 to C- 5 is operating at any given moment in time. As a result, the tunable signal 30 has only a single spectral peak. The full scan band is achieved by sequentially energizing the SLED chip of each channel C- 1 to C- 5 . This tunable signal is scanned over the entire scan band covered by the SLED chips of channels C- 1 to C- 5 turning on the SLED chips in series, or sequentially.
[0087] In another mode, each of the SLED chips is operated simultaneously. As a result, the tunable signal has spectral peaks in each of the scan bands, covered by each of the SLED chips 110 simultaneously. This system results in a more complex detector system 300 , which must demultiplex the separate scan bands from each of the SLED chips 110 from each of the channels at the detector. Specifically, in one embodiment, five (5) detectors are used with a front-end wavelength demultiplexor.
[0088] FIG. 9 shows an embodiment of the tunable source 10 that has both increased power and increased scanning range over a single SLED. It comprises two subcomponents, which are configured as illustrated in FIG. 7 embodiment. Specifically, each channel C- 1 , C- 2 has two SLED chips 110 A, 110 B that are polarization combined. The output is isolated by an isolator 120 and then filtered by a tunable filter 116 for each channel C- 1 , C- 2 . The signals from the two channels are then wavelength multiplexed using a combination of a fold mirror 170 and a dichroic or WDM filter 172 . Specifically, the dichroic mirror 172 is transmissive to the scan band of the SLED chips 110 A, 110 B of channel C- 1 , but reflective to the SLED chips 110 A, 110 B of channel C- 2 .
[0089] In order to improve the manufacturing yield of the FIG. 9 embodiment, in one implementation, each of the channels C- 1 and C- 2 are fabricated on separate sub-benches SB- 1 and SB- 2 . The sub-benches SB- 1 , SB- 2 are then bonded to each other or to a common bench in order to yield the FIG. 9 embodiment.
[0090] FIG. 10 illustrates still another embodiment, which covers a wide spectral band. Specifically, it includes five SLED chips 110 A to 110 E. A series of first lens optical components 118 are used to collimate the beams from each of the SLED chips 110 A- 110 E. In the present embodiment, the SLED chips 110 A to 110 E, each operate over different spectral bands. They are then wavelength combined using a combination of fold mirrors and filters 156 , 160 , 162 , 164 and 158 , as discussed with reference to the FIG. 8 embodiment.
[0091] The FIG. 10 embodiment further includes, preferably, two isolators 120 A, 120 B. These isolate respective tunable filters 116 A, 116 B. Lens components 180 , 182 , 184 , and 186 are used to couple the optical signal generated by the SLEDS 110 A- 110 E, through the first tunable filter 116 A and the second tunable filter 116 B of the tunable filter system 200 , and then, through the wavelength tap 149 and the power tap 152 to the endface 104 of the optical fiber 102 .
[0092] The use of the five SLED chips 110 increases the effective scan band of the tunable source 10 . In the preferred embodiment, the tandem tunable filters have free spectral ranges FSR as illustrated in FIG. 11 .
[0093] Specifically, filter 1 116 A, and filter 2 116 B have different free spectral ranges. As a result, they function in a vernier configuration. This addresses limitations in the free spectral range of the tunable filters individually.
[0094] Typically, if a single tunable filter was used, its free spectral range would have to be at least as wide as the total scan band of the broad band signals generated by the sources. In the illustrated embodiment, the tunable filters are combined to increase the free spectral range of the tunable filter system, since the peak transmissivity, through both tunable filters 116 A- 116 B, only arises at wavelengths where the passbands of the two filters 116 A- 166 B are coincident.
[0095] FIGS. 12A and 12B show tunable detector systems 20 , to which the principles of the present invention are also applicable.
[0096] Specifically, with reference to FIG. 12A , the tunable detector system generally comprises a package 132 and an optical bench B- 1 , which is sometimes referred to as a submount. The bench B- 1 is installed in the package 132 , and specifically on a thermoelectric (TE) cooler 134 , which is located between the bench B- 1 and the package 132 , in the specific illustrated embodiment.
[0097] The package 132 , in this illustrated example, is a butterfly package. The package's lid 136 is shown cut-away in the illustration.
[0098] The tunable detector optical system, which is installed on the top surface of the bench B- 1 , generally comprises the detector system 300 , the tunable filter system 200 , and an optional reference source system 24 .
[0099] In more detail, the optical signal from the target S- 1 to be monitored is transmitted to the system via a fiber pigtail 310 , in the illustrated example. This pigtail 310 terminates at an endface 312 that is secured above the bench B- 1 using a fiber mounting structure 314 in the illustrated implementation. The optical signal passes through a first lens optical component 316 , which collimates the beam to pass through an isolator 320 . A second lens optical component 318 launches the optical signal into the tunable filter system 200 . A MEMS implementation of the tunable filter is shown. The filtered signal passes through a third lens optical component 322 and is then detected by an optical signal detector 324 .
[0100] In the illustrated implementation, each of the lens and tunable filter optical components comprises the optical element and a mounting structure that is used to secure the optical element to the bench, while enabling most installation alignment.
[0101] Turning to the path of the optical reference, the emission from a reference light source 42 , such as a broadband source, e.g., a SLED, passes through reference lens optical component 44 to a fixed filter 46 , which, in the present implementation, is a fixed etalon. It converts the broadband spectrum of the SLED 42 into a series of spectral peaks, corresponding to the various orders of the etalon transmission, thereby producing the stable spectral features of the optical reference.
[0102] The optical reference is then reflected by fold mirror 48 to a dichroic or WDM filter 50 , which is tuned to be reflective at the wavelength of the optical reference, but transmissive within the band of the optical signal. Thus, the optical reference is similarly directed to the optical filter system 200 .
[0103] At the detector system 20 , a dichroic filter 52 reflects the optical reference to a reference detector 54 .
[0104] FIG. 12B shows an operationally similar tunable optical filter system 20 , for the purposes of the present invention. Reference numerals have been used for functionally equivalent parts. The differential between the two designs lies in the design of the detector system 300 . This second embodiment utilizes only a single detector 324 , 54 that detects both the optical reference and the optical signal. In this illustration, the package is not shown for clarity.
[0105] FIG. 13 shows another embodiment of the tunable detector 20 . The signal from the target is transmitted to the detector 20 via fiber 310 . A first lens component 316 collimates the light from the fiber. Second lens components 318 couple the light into the tunable filters 116 A, 116 B of the filter system 200 . Third lens components 322 focus the light to the detector system 300 .
[0106] This version uses two tunable filters 116 A, 116 B, each filtering a portion of the scan band. Corresponding detectors 334 A, 334 B detect the transmitted signal from each filter.
[0107] The spectrum is divided into two subbands by WDM filter 360 , which reflects half of the spectral scan band to the second filter 116 B via fold mirror 362 . The other half of the spectrum is transmitted through the WDM filter 360 to tunable filter 116 A.
[0108] FIG. 14 shows a single bench fully integrated system according to still another embodiment. It generally operates as described relative to the FIG. 8 embodiment. Specifically, it uses a series of SLEDs in five channels, yielding a tunable source 10 , to generate a wide band tunable signal 30 . The detector system 300 is integrated on the same bench B and the tunable source. Specifically, light returning from the target in fiber 310 is coupled to detector 334 using lens component 322 .
[0109] FIG. 15 shows another single bench fully integrated system according to still another embodiment. Here, the light to and from the target is carried in the same fiber 102 , 310 . The tap substrate 152 is used to direct outgoing light 30 to the power detector 154 and light returning from the target to the detector 334 .
[0110] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.
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BACKGROUND OF THE INVENTION
The present invention relates to an arrangement in a sewing machine, comprising a needle bar having a needle, a feed dog for feeding a fabric to be sewn, and a vertically movable presser bar having a presser foot and a presser spring. The presser bar is actuated by a power-driven actuating means connected to the presser spring and slidable in parallel with the presser bar. The actuating means is movable relative to the presser bar to control the presser foot pressure and to engage the presser bar in order to raise and lower the presser foot during the sewing procedure in accordance with a predetermined program.
A conventional, stationary presser foot creates a braking action on an upper fabric layer due to friction between the fabric and the presser foot. The friction results in a risk of mutual displacement of the fabric layers in that the distance of feeding of the upper layer will be shorter than that of the lower layer which is in direct contact with the feed dog. As is easily seen, such mutual displacement of the fabric layers will have a negative effect on the sewing performance. The problem is particularly evident in the case of material providing great friction when engaging the presser foot, but also when sewing soft, compressible fabric material.
In order to provide a solution to the above problem it is known to use an arrangement having a slidably journalled presser foot. Raising movement of the presser foot is provided by the drive mechanism of the needle bar. However, in such an arrangement it is not possible to obtain raising and lowering of the presser foot at the appropriate moments during the sewing procedure, and the performance of the arrangement has therefore not appeared to be satisfactory.
SUMMARY OF THE INVENTION
It is an object of the invention to minimize or eliminate the disadvantages or deficiencies of known arrangements of this kind.
Another object is to provide pleat and tuck sewing by the arrangement according to the invention. To this end an embodiment has been provided in which the presser foot has a top feed ruffler driven by the vertical movement of the presser bar.
A further object is to enable rapid and simple adjustment of the sewing machine between conventional sewing and sewing with the arrangement according to the invention having a raisable presser foot.
In one embodiment of the invention, the presser foot is slidably journalled relative to the presser bar in order to follow the fabric during feeding and adapted to be raised between feeding steps and resiliently actuated in order to, when raised, be returned to an initial position. By such an arrangement it is possible to a great extent to eliminate the braking action exercised by a conventional, stationary presser foot on the upper fabric layer due to friction between the fabric and the presser foot.
In further accordance with the present invention, the presser foot is horizontally movable relative to the presser bar together with the fabric during feeding steps. Actuating means are operable to raise the presser foot independently of the movement of the needle bar. The presser foot is actuated by resilient means in order to, when raised, be returned to an initial position relative to the presser bar.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further features of the present invention will be apparent with reference to the following description and drawings, wherein:
FIGS. 1-4 illustrate diagrammatical side elevational views of a first embodiment of an arrangement according to the present invention, in different positions;
FIGS. 5-7 illustrate diagrammatical side elevational views of a second embodiment of the present invention, in different positions;
FIGS. 8 and 9 illustrate perspective views of a third embodiment of the present invention in two different positions; and
FIGS. 10 and 11 illustrate side elevational views of the third embodiment of the present invention in two different positions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The arrangement shown in FIGS. 1-4 comprises a needle bar 10 having a needle 11, a presser bar 12 having a presser foot 13, and a fabric feed dog 14. The presser foot 13 is slidably supported on a shaft 15 extending through horizontal slots 16 and the shaft 15 is provided with rollers 17 to reduce friction. In order to return the presser foot 13 to an initial position, tension springs 18 are provided which are attached between the shaft 15 and the respective forward and rearward ends of the presser foot, as illustrated.
On the presser bar 12 a slidable sleeve 19 is provided which has a rack 20 engaging a pinion 21 driven by a stepping motor (not shown). The sleeve 19 is also provided with a bracket 22 to which one end of a presser spring 23 is attached. The other end of the spring is attached to a bracket 24 which is fixed to the presser bar 12.
In the stage shown in FIG. 1 the presser foot 13 has been lowered and the presser spring 23 is tensioned by the rack 20 to obtain an appropriate presser foot pressure. The needle 11 has left the fabric and the feed dog 14 has just commenced a feeding movement. In FIG. 2 the feeding movement has been completed whereby the presser foot 13 has been laterally displaced together with the fabric.
In FIG. 3 the needle 11 is shown in a lowermost position and the presser foot 13 is in a raised position and has been returned to its horizontal initial position by action of the springs 18. The presser foot 13 is raised upwards by the sliding sleeve 19 due to operation of the rack 20 and pinion 21, whereby the upper end of the sleeve 19 engages the bracket 24 to raise the presser bar 12. Raising movement of the presser bar 12 is controlled such that the needle 11 penetrates the fabric to fix the same before the presser foot 13 is raised by the sliding sleeve 19.
In FIG. 4 the presser foot 13 is again in its lowered position and the needle 11 is in its upward stroke. The sliding sleeve 19 has moved downwardly due to action of the rack 20 and pinion 21. The presser foot 13 has been lowered and the presser spring 23 has been tensioned to a predetermined presser foot pressure before the needle 11 leaves the fabric. It is thereby ensured that the fabric is held in its correct fixed position during the entire sewing procedure.
A second embodiment of the present invention is shown in FIGS. 5-7, and includes a needle bar 40 having a needle 41, a presser bar 42 having a presser foot 43, and a feed dog 44. The presser foot 43 is slidably supported on a shaft 45 extending through horizontal slots 46 and having rollers 47 and tension springs 48, as have been described hereinbefore with reference to FIGS. 1-4.
The presser bar 42 has a slidable sleeve 49 mounted thereover. The sleeve 49 is provided with a first rack 50 which engages a pinion 51 driven by a stepping motor (not shown). The sleeve 49 includes a bracket 52 to which one end of a presser spring 53 is attached. The other end of the presser spring 53 is attached to a bracket 54 which is fixed to the presser bar 42.
As is best seen in FIGS. 6 and 7, (wherein a portion of the presser foot 43 has been removed for purposes of clarity), a supporting foot 55 is attached to a vertically slidable bar 56. A rotatably journalled pinion 57 mounted on a middle portion of the bar 56 engages a second rack 58 of the sleeve 49 and a third rack 59 of an arm 60 connected to the bracket 54 and thereby fixed to the presser bar 42. The second and third racks 58, 59 together with the pinion 57 form a differential gear controlling vertical movement of the bar 56 and the supporting foot 55, as will be described below.
In FIG. 5, the presser foot 43 is in an elevated, non-operative position. Adjustment to this position takes place by sliding the sleeve 49 upwards by action of the stepping motor driven pinion 51 and the first rack 50 until the sleeve 42 engages the bracket 54. Upward movement of the sleeve 49 also raises the bar 56, due to engagement of the second rack 58 with the pinion 57.
During further upward movement, the sleeve 42 will entrain or force the presser bar 42 upwardly, thereby raising the presser foot 43 to the illustrated position. During such further upward movement, the second and third racks 58, 59 will move upwardly in a simultaneous and parallel fashion. By simultaneous and parallel raising of the second and third racks 58, 59, the pinion 57 is entrained between the racks 58, 59, whereby the bar 56 and the supporting foot 55 will also be further raised to the illustrated position.
A sewing procedure in accordance with the second embodiment is illustrated in FIGS. 6 and 7. In FIG. 6, the presser foot 43 has been lowered, the needle 41 is in its elevated position, and the feed dog 44 has just completed a fabric feeding stroke. The presser foot 43 is in a horizontally displaced position. The presser foot pressure is controlled by tensioning the presser spring 53 by means of the rack 50, pinion 51, sleeve 42, and bracket 52. The supporting foot 55 is held in a raised position by the differential gear 57, 58, 59 and, therefore, does not obstruct feeding of the fabric.
In FIG. 7, the needle 41 is shown in its lowermost position and the sleeve 49 has been moved further downwards whereby the supporting foot 55 has been lowered to engage the fabric. The presser foot 43 is in an elevated position and has been returned to its initial horizontal position by action of the springs 48, as illustrated.
Upward movement of the presser foot 43 is provided by the differential gear 57, 58, 59 by sliding the sleeve 49 a further distance downwards while the supporting foot 55 engages the fabric. Due to this engagement, downward movement of the sleeve 49 is transformed, via the pinion 57, into an upward movement of the arm 60 which, in turn, raises the presser bar 42 to the illustrated position. Thus, engagement of the supporting foot 55 on the fabric is used to raise the presser foot 43. It is thereby ensured that the supporting foot 55 holds the fabric in a fixed position during raising and lowering of the presser foot 43, whereby undesired sliding of the fabric is prevented.
In the second embodiment of the present invention, the fabric will be alternatingly held by the presser foot 43 and the supporting foot 55 during the entire sewing procedure. It is thereby further ensured that the fabric will not be displaced in an undesirable manner, and the supporting foot 55 also prevents possible turning or rotation of the fabric around the needle 41 during raising of the presser foot 43.
FIGS. 8-11 show a third embodiment of the present invention adapted for pleat or tuck sewing which is controlled by a stepping motor driven presser bar 12 (FIGS. 1-4). The third embodiment comprises a presser foot 63 having a vertical leg 64 fixed to an upper bracket 65 which, in turn, is slidable on the presser bar 12. A lower bracket 66 is fixed to the presser bar 12. By raising the presser bar 12 until the lower bracket 66 engages the upper bracket 65 (FIGS. 9, 11) the presser foot 63 can be raised or moved upwardly from the underlying base.
A supporting plate 67 is provided relatively in front of the presser foot 63 and connected to the presser foot 63 by a spring 68. On top of the supporting plate 67 there is provided a reciprocatable top feed ruffler 69 which is attached to a rectangular frame 70. The frame 70 is articulatedly connected to the upper bracket 65 by means of a first pair of angled levers 71. The levers 71 are connected by means of pivot pins 72 to the upper end of a second pair of levers 73, the lower ends of which are connected to pivot pins 74 of the lower bracket 66. A first pair of tension springs 76, (one shown), extends between lower attachments 77 adjacent to the pivot pins 74 and upper attachments 78 on the levers 71. A second pair of tension springs extends between the rear end of the frame 70 and the pivot pins 72.
For tuck forming, the stroke of the feed dog 14 is set to zero when the needle 11 is in its lower position. To form a tuck of a desired length, the presser bar 12 and the lower bracket 66 are moved downwards whereby the frame 70 together with the top feed ruffler 69 are moved forward by the levers 71, 73. The top feed ruffler is held in engagement with the fabric by the springs 79. The desired tuck length is set by the control unit of the machine, and the position of the presser bar 12 and the top feed ruffler 69 is determined by an optical difference meter (not shown) of a known type. In FIGS. 8 and 10 the top feed ruffler 69 is shown in its maximum forward position which provides for a maximum tuck length. The pressure bar 12 is then returned upwards, and the top feed ruffler 69 returns to the position shown in FIGS. 9 and 11, and thereby entrains the fabric towards the needle 11, which in this stage is in its upward stroke, while simultaneously forming a tuck. The pressure bar 12 is raised to a position in which the presser foot 63 is raised slightly at the same time as the fabric tuck is inserted under it. The presser foot 63 is then lowered and the presser foot pressure is adjusted to a normal value, and the needle 11 is subsequently lowered. The top feed ruffler 69 remains in the position shown in FIGS. 9 and 11 during the descending movement of the needle 11, and thereby ensures that the needle 11 penetrates all of the three fabric layers. When the needle 11 is in a lower position, the feeding is adjusted to a preselected stitch length for sewing a number of normal stitches without tuck forming.
The tuck forming interval is adjusted by means of the control unit of the machine. The adjustment can be made in different ways. One possibility is to select a number of normal stitches between each tuck. It is also possible to set a number of tucks per unit of length, or a fabric contraction as a percentage of the fabric length.
When a tuck is formed, the fabric thickness below the presser foot increases which is sensed by the mentioned optical difference meter. In response to the sensed fabric thickness an automatic adjustment of the thread tension and the presser foot pressure is carried out in order to obtain the best sewing performance possible.
While the preferred embodiment of the present invention is shown and described herein, it is to be understood that the same is not so limited but shall cover and include any and all modifications thereof which fall within the purview of the invention.
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An arrangement in a sewing machine including a fabric feed dog (14; 44) for feeding a fabric to be sewn, and a vertically movable presser bar (12; 42) having a presser foot (13; 43; 63) and a presser spring (23; 53). The presser bar is actuatable by a power-driven actuator(19; 49) connected to the presser spring and slidable in parallel with the presser bar. The actuator is movable relative to the presser bar to adjust the presser foot pressure and operatively connected to the presser bar to raise and lower the presser foot during the sewing procedure in accordance with a predetermined program. In one embodiment, the presser foot (13, 43) is slidable to follow the fabric during the feeding step. In another embodiment, the presser foot (63) is provided with a top feed ruffler (69, 70) for forming tucks or pleats in the fabric being sewn.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 60/604,381, filed Aug. 25, 2004, herein incorporated by reference in its entirety.
GOVERNMENT INTEREST
The invention herein may be manufactured, used and licensed by or for the U.S. Government.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to enhancing the visibility of the current nuclear, biological and chemical weapon (NBC) marking system utilizing a visible and IR flashing light.
2. Background
Throughout the 1980s, the Chemical Corps sought a nuclear, biological, and chemical (NBC) reconnaissance capability that would prevent the possibility of an unwarned encounter with contaminated terrain. With the type classification of the German Transportpanzer 1 Fuchs vehicle as the standard NBC reconnaissance asset, the U.S. Army first became capable of rapidly detecting terrain contaminated with chemical agents. The U.S. variant of this vehicle was designated as the M93A1 Fox Nuclear, Biological, and Chemical Reconnaissance System. The system includes a marker set which consists of a weighted base, a wire mast, and pennants for each class of NBC hazard. Enough components to assemble 175 markers are stored inside the crew compartment of the vehicle. There is a marker chute at the rear of the vehicle which allows assembled markers to be dropped outside without compromising the collective protection system of the vehicle.
Starting with World War I (1914-1918), various methods of marking contaminated areas have been used. All have shared the same goal-preventing an unwarned encounter with a chemically contaminated area. The protocol for annotating the pennant or marker has remained relatively unchanged over the years. When emplaced, the unit, the date-time group, and the hazard are written on the marker, typically using a grease pencil. The identification of these markers is a common task at Skill Level 1 for all soldiers (found in Soldier Training Publication [STP] 21-1-SMCT, Soldier's Manual of Common Tasks Skill Level 1, task number 031-503-1019, React to Chemical or Biological Hazard/Attack). The adequacy of the Fox marker system was an issue during the field-testing of the system before its type classification. With the limited number of markers on board, it was clear that placing them around a typical contaminated area would immediately consume the entire basic load of markers. Soldiers also raised issues concerning the visibility of the markers during periods of darkness and the limited amount of information available at the marker. Following the type classification, field units began to report that the markers were difficult to see and tended to tip over in rough terrain.
In 1997, the U.S. Army Chemical School's Directorate of Combat Developments at Fort McClellan, Ala., drafted a concept for the digital marking of contaminated areas. An evaluation of a concept entitled Smart Marker was proposed. In 1998, the U.S. Army Maneuver Support Battle Lab, Fort Leonard Wood, Mo., managed a limited-scale in-house project designed to demonstrate a long-duration infrared (IR) beacon. A circuit was then assembled based upon an LM3909 integrated circuit and other components purchased at a local electronics store.
The goal of this early experiment was to determine if a small, thumbnail-sized (1 centimeter by 1 centimeter) IR beacon could be used to improve the visibility of a Fox NBC marker for a period of two weeks without a battery change. This experiment was a success: the beacon worked for 87 days (on one AAA battery) without a failure.
The success of the beacon project prompted an investigation into the scope of the capabilities that could be included in a marking system product improvement. The Maneuver Support Center Battle Lab was sponsoring an Army advanced technology demonstration that looked at the development of decision tool software for NBC personnel. The prototype software was installed on a commercially available Windows® CE-based personal data assistant (PDA). The PDA mirrored the capabilities of laptop computers with the same graphics, text files, database utilities, and IR port. When the software contractor delivered the products, they were demonstrated on a PDA that also had a personal computer radio frequency (RF) modem card for Internet access. This allowed the user to obtain online maps via a Web site. Further investigation revealed small Global Positioning System integrated circuits that could be used inside a Smart Marker.
A demonstration to transfer a field survey form and a graphic hazard from a laptop to a PDA was conducted. This caused further interest in the concept. The Smart Marker concept was revised and improved based on the combination of technology demonstrations, market surveys, and collateral readings resulting in development of a U.S. Army Training and Doctrine Command Concept Evaluation Program (CEP) proposal.
The funding needed to conduct the Smart Marker CEP was approved in 1999. The goals of the program were to improve the visibility of the marker and increase the amount of information it makes available. A statement of work was then prepared and a solicitation for bid issued. The University of Missouri-Rolla was selected for the contract, and work began. Government personnel provided the background information on the concept and its goals for the experiment. The one government-specified constraint for the design team was to use commercial off-the-shelf (COTS) technology or components whenever possible.
The project was partitioned into four phases, and transitioning from one phase to the next was contingent upon the results of an in-progress review (IPR). Phase I was a front-end analysis that examined the varying methods of addressing the problems of the existing markers. Phase II was the fabrication of breadboards (alpha prototypes) that demonstrated function and potential and resolved any shortcomings of the existing system within the constraints specified. Phase III involved fabricating and demonstrating functioning prototypes for field demonstration. Phase IV was the demonstration of a working prototype in a limited-objective experiment.
There were three senior design teams assigned to develop three different designs. Each team consisted of one electronics/computer engineering student and two mechanical engineering students. Two of the teams also had one engineering management student each. The three teams arrived at two design approaches. Two of the groups elected to repackage a PDA to take advantage of its built-in functionality. The other team opted for the use of COTS electronic components that were coordinated by a microcontroller. Some time after the work had begun, the teams were reorganized to partition the effort. The three mechanical teams remained, but the electronics development team was consolidated.
The researchers used computer-assisted design and manufacture to create the marker prototypes. Each team had a different solution to the problem of marker stability. One team decided upon a multipod approach using multiple short legs that provided at least three points of contact regardless of its directional orientation. The multipod approach was the closest to the design of the existing marker, but the approach did not demonstrate well during the field trials. An alternative design approach used a counterweighted cylinder with a self-orienting antenna mast. This technique had the advantage of simplicity of design but was difficult to deploy from the Fox and suffered from durability problems. The most successful mechanical design had articulated legs and was self-righting. When cost was considered, it was decided that this approach, however elegant, was not practical.
The electronics module was the most successful element of the design approach. Initially the design teams had two different approaches to the electronic functions. As the teams reviewed the requirements, it became obvious that most of the requirements could be met with a PDA. The battery well, keyboard, and visual display are the biggest parts of the PDA. These parts are unnecessary to the marker function. Two of the teams concluded that a PDA could be repackaged to meet the need. The third team thought that this approach was inefficient and that a fresh breadboard should be developed using miniature COTS electronic components. This approach was selected at a midpoint IPR.
With this decision, the teams were reorganized, and a composite team was created to design an electronics module that was compatible with all three mechanical designs. In response to the reorganization, the scope of work statement was adjusted. This team was given a size constraint for the marker and was instructed to conduct a design-to-fit study. The idea was that the actual device could be larger than the design constraint if standard design practices could configure the electronics to fit the constraint. The engineers took a modular approach, placing the components inside a clear plastic enclosure. The use of a miniature frequency-hopping transceiver ensured that it would be possible to download the marker's data from standoff distances.
A standard graphic interface was designed so that service members who are familiar with WINDOWS products could use the supporting software easily. This approach was an unqualified success, because personnel who were familiar with WINDOWS applications had no difficulty using the prototype software. The terminal used in the field was a standard military contract laptop computer with a Windows NT® operating system. Accordingly, soldiers with experience using these tools had no challenges with the Smart Marker and its supporting software.
The field experimentation was very successful. The Smart Marker concept evaluation demonstrated that by leveraging commercially available technology, it is possible to improve the Fox's (M93A1 Fox Nuclear, Biological, and Chemical Reconnaissance Systems) marking of hazard areas dramatically. Simply adding different flags and a commercially available stick-on beacon makes a significant difference in the ability to detect the marker during periods of limited visibility. Leveraging available technology allows the standoff download of detailed hazard information via RF modem or digital download via the IR or the hardwire communication port. In the case of the RF mode, detailed hazard data was visible in the cab of a truck 300 meters before the marker was encountered. While this project focused upon the Fox, its findings could be useful for a number of different applications, such as minefield, hazard, and traffic-control marking.
The current method of tactically marking NBC contaminated areas utilizes a weighted self-righting base with an 18 inch staff that has a flag attached. This marker is deployed through a sleeve in the hull of the NBC recon vehicle, which limits the overall length and diameter. The visibility of this item is limited to day time only and depending on the viewing angle can be nearly invisible from 50 feet away. Night time visibility is currently marginal reflectivity at best. This allows soldiers to accidentally enter contaminated areas. A need exists for a device to warn soldiers of a contaminated area up to 500 meters away while still being deployable through the NBC recon vehicle sleeve.
SUMMARY OF THE INVENTION
The invention relates to an NBC warning light including a plurality of warning indicators, comprising an infrared light source and a visible light source; a electronics assembly operatively connected to selectively operate said warning indicators; a switch, said switch having a plurality of operable positions, wherein each of said operable positions commands said electronics assembly; and a power source.
The NBC marker light is designed to be simplistic, lightweight, and expendable. The case is two pieces, designed for ease of assembly. The assembly typically includes a circuit card, one or two or more coin batteries, IR and visible LEDs and a custom designed rotary switch. A diffuser is designed to enhance side visibility in all directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a first embodiment of the invention.
FIG. 2 is a cut-away view of a second embodiment of the invention.
FIG. 3 shows a battery and electronics assembly to be used in the invention.
FIG. 4 is a side view of the assembly shown in FIG. 3 .
FIG. 4A shows a bottom view of the embodiment of FIG. 1 with a loop attached to its diffuser and a five-fingered clip added to its body.
FIG. 4B shows a portion of the embodiment of FIG. 4A attached to a pole by the five fingered clip.
FIGS. 5-7 are circuit diagrams showing typical circuitry which can be used with the invention.
FIGS. 8-12 show photographs of the embodiment of FIG. 1 and its electrical components.
FIGS. 13-18 show a second embodiment of the marker light 110 of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the nuclear, biological and chemical weapon (NBC) marker light 10 of the invention. The light 10 typically includes an upper case 12 and a lower case 14 , housing a battery 30 and electronics assembly 20 ( FIG. 3 ) therein. Typically, one or two or more coin batteries 30 are employed. Preferably, a pair of warning indicators 22 is disposed at an upper end of the battery 30 and electronics assembly 20 , and extending through an aperture in the upper case 12 .
The warning indicators 22 preferably include an infrared (IR) light source 22 A and a visible light source 22 B, which can be independently operated to actuate multi-position switch 28 depending upon the selected mode. The mode can be selected by rotating a selection collar 24 to align with indicia provided on either the upper case 12 or the lower case 14 . Additionally, selection collar 14 can be integral with either of the upper case 12 or the lower case 14 , such that rotation of the upper case 12 with respect to lower case 14 (or vise versa) rotates selection collar 24 .
Typically, marker light 10 has a generally cylindrical shape, having an outer diameter of between 1 and 5 inches, preferably between about 1 and 3 inches, for example approximately 1.125 inches. The length of the marker light 10 is typically between 1 and 5 inches, preferably between 2 and 4 inches, for example approximately 3 inches long.
Preferably, both the upper case 12 and the bottom case 14 are injection molded, and formed from black ABS plastic. However, any construction is permitted. For example, other plastics, such as polyolefins, natural materials, such as wood or metals, or composites may be utilized. However, the particular construction must be capable of withstanding the environmental conditions of the expected use.
In a first embodiment, the upper case 12 and the lower case 14 snap together permanently. As shown in FIG. 1 , lower ends of tabs 21 , 23 , 25 , 27 snap fit over a rim of the lower case 14 . The lower case 14 of the case rotates in the upper case 12 to actuate a switch 28 contained as part of the battery and electronics assembly 20 ( FIG. 3 ). Positions are identified by a raised bar 40 on the bottom of the lower case 14 and engraved tabs, e.g. tabs 21 , 23 , 25 , 27 on the top part of the light 10 . Typical markings include: WH-S, WH-F, a solid raised bar, IR-F, IR-S, indicating white-steady, white-flash, off, infrared-flash and infrared-flash, respectively. In one embodiment, the indicia are provided on selection collar 24 as shown in FIG. 1 . The function of light 10 , when each of the various indicia is selected will be hereinafter described.
The switch 28 is a typically rotary cam actuating five nickel plated contacts that mate with adjoining surfaces on the circuit board. The switch can be heat staked on to the circuit board which is designed to control flash length, intensity and frequency of the selected warning indicators. Typical configurations for the circuitry are shown in FIGS. 5-7 .
The battery and electronics assembly 20 also includes a power source, such as a pair of batteries 30 . In one embodiment, the batteries are CR2032 type batteries, held in place by a battery clip 32 , and typically have a life of a minimum of 72 hours at −20° C.
While the preferred embodiment of light 10 is not designed to be re-used upon expiration of the power source, it is within the scope of the invention to produce light 10 with a replaceable power source. Typically, this is accomplished by making upper case 12 removable from lower case 14 , and batteries 30 removable. Additionally, the power source may provided with a rechargeable apparatus, such as a small solar cell or a weight, which when moved generates an electrical charge sufficient to recharge the power source.
In a preferred embodiment, the circuit board slides into a locating slot in the upper case 12 and is held in place by the lower housing 14 . A clear polycarbonate diffuser 26 at the top covers both IR LED 22 A and Visible light LED 22 B. One side of the diffuser 26 is typically provided with a circular loop 81 of about ¼ inch diameter. FIGS. 4A and 12 illustrate the loop 81 attached to its diffuser 26 and a five-fingered clip 82 attached to or extending from the upper case 12 . This loop 81 is designed to secure the bottom of the NBC flag utilizing a standard zip tie. This loop 81 and zip tie can be used to secure the light to any number of other objects requiring marking. The 5 finger clip 42 is designed to securely attach the light to the current NBC Marker staff (pole) 80 . FIG. 4B shows a portion of the embodiment of FIG. 1 attached to the pole 80 by the five fingered clip 42 .
The lower portion of the case also typically has a slot 44 for a battery disconnect pull-tab 43 for shipping. FIG. 4A shows a bottom view of the embodiment of FIG. 1 with the pull tab 43 and slot 44 . The disconnect tab has one or more punched holes 41 to connect a trip wire (not shown) to use as a covert IR warning device.
The invention includes selectable Infrared (IR) and Visible light sources 22 A, 22 B to upgrade and enhance the current NBC marker system. This is a unique design that fits seamlessly into the current NBC marking system without modification. This device provides a means to increase the day and nighttime visibility of the current NBC marker system by several hundred meters while utilizing the marker's current staff and base. The light is designed to be small lightweight, and disposable. Its intended performance is to be visible at 500 meters at night and have a minimum longevity of 72 hours at minus twenty degrees Celsius. It has two flash frequencies; one hertz and one and one half hertz for either IR or Visible light. It is designed with a clip on the case that mates with the current NBC marker staff and a tie loop to secure the bottom of the marker flag in the correct position for added reflectivity. Its rotary switching mechanism has five modes: fast and slow frequency rates for IR or Visible light and an off position. The rotary switch allows for easy mode selection while wearing MOPP4 (Mission-Oriented Protective Posture level 4) gear. (For example, at MOPP4 soldiers should first mask, then don protective gloves. Overgarments should be closed, and then overboots should be put on).
The rotary switch also provides positive position lock for feedback while wearing gloves. The overall weight is typically less than 10 oz. and will not affect the self-righting capability of the NBC marker. It also features a 10 second turn—on delay to allow placement and movement before marking the area.
The operation of light 10 preferably proceeds as follows. As packaged and shipped, light is packaged with the switch 28 in the OFF position wherein the raised bar on the bottom of the lower part 14 of the case would be aligned with the “OFF” marking 21 . When a Visible Light Mode (“VLM”) is desired, while holding the upper case 12 , with the diffuser 26 pointing away, the lower case 14 clockwise is rotated to align the raised bar on the bottom of the lower part of the lower case 14 with the correct marking. The first position, associated with the marking “WH-F” 23 ( FIG. 1 ) is visible light, fast speed. The second position, associated with the marking “WH-S” 25 is the visible light slow speed.
To activate the infrared light mode (“ILM”), the lower case 14 is rotated counter clockwise with respect to the upper case 12 . The first position, associated with the marking “IR-F” (not shown) is infrared light, fast speed. The second position, associated with the marking “1F-S” 27 is the infrared light slow speed. This feature allows the light to designate clear (safe) paths through the contaminated area. This is typically done by placing a series of markers flashing at slow speed in a first line and a second set of markers flashing at high speed in a second line alongside the first line to define the path between the two lines.
Although the markings are described as coinciding with only five different operation modes, i.e., off, VLM fast and slow, and ILM fast and slow, it is within the scope of the invention to modify the operation modes. For example, in one embodiment, operation modes can include additional VLM and/or ILM speeds to indicate various conditions, such type of NBC, or decontamination status of the area. In such a case, the number of markings would be increased.
The warning indicators 22 may also include other warning signals, such as various colors, or signals invisible to the naked eye. Such signals can include ultra-violet or radio signals, which require specialized goggles or other equipment to process or analyze the signal.
To mount the light 10 for use in the field, typically, the light 10 is clipped to the NBC marker staff with a lens loop just below the bottom of the flag, and light 10 is secured at the bottom of the flag to the loop using the tie provided with the flag. The case of the light 10 also typically has a slot for a battery disconnect pull-tab for shipping. The pull-tab is removed just prior to deploying the marker.
Although light 10 is not designed to be decontaminated, in some embodiments, it may be constructed to withstand a decontamination procedure.
Furthermore, although light 10 is designed to be manually actuated, it is within the scope of the invention to equip light 10 with an automatic detection and analysis apparatus 50 (not shown) which can actuate switch 28 upon detection of any NBC contaminant with manual activation. In these embodiments, the apparatus 50 can be designed as described by U.S. Published Application No. 2004/0257227 and U.S. Pat. Nos. 5,278,539 and 5,576,952, each of which is incorporated by reference it its entirety.
The light 10 may also be designed to give an advance warning to personnel outside the visible range of the light 10 by transmitting a signal to such personnel, which signal can include various data, such as type of contaminant and location, and may be activated upon a command from apparatus 50 or simply when light 10 is manually activated.
FIGS. 5-7 are circuit diagrams showing typical circuitry which can be used with the present invention.
FIG. 5 shows circuitry associated with the multi-position switch 28 employed in the present invention. This includes the battery 30 , the visible LED 22 B, the IR LED 22 A and the multi-position switch 28 .
FIG. 6 also shows details of the card containing the circuitry associated with the multi-position switch 28 employed in the present invention. This shows output 154 to the visible LED 22 B, output 155 to the IR LED 22 A, capacitor 148 , resistor 147 , resistor 146 , capacitor 145 . This also shows output 156 to switch 28 (not shown in this figure), resistor 149 , capacitor 150 , resistor 151 , resistor 152 , and resistor 153 . This circuitry controls flash intervals.
FIG. 7 shows a schematic of the circuitry for controlling flash intervals. This contains the battery 30 , the pull tab 43 , a switch 60 for the IR LED 22 A, a switch 61 for the visible light LED 22 B, CMOS device 63 , switches 65 , 66 for switching flash rate control, and field effect transistor (N channel MOSFET) 64 . FIG. 7 also shows R1-R7 resistors and C1-C3 capacitors.
FIGS. 8-12 show photographs of the embodiment 10 of the present invention and its electrical components 20 .
FIGS. 13-18 show a second embodiment of the marker light 110 of the present invention. The marker light 110 has a diffuser 126 , tabs 125 , loops 181 and a two fingered clip 182 . Its lower body has a slot 144 ( FIG. 14 ) for holding a pull tab (not shown) similar in operation to the slot 44 and pull tab 43 of the first embodiment 10. The second embodiment 110 operates substantially the same as the first embodiment 10. and is provided with an IR LED or bulb 122 A and a visible light LED or bulb 122 B controlled by a multiple position switch 128 ( FIG. 16 ) and powered by one or more batteries 130 ( FIG. 17 ).
It should be noted that while IR LEDs and visible light LEDs are shown in the above-described embodiments, other measurable signal generators may be substituted. For example, two different color visible lights could be employed and/or bulbs rather than LEDs could be employed.
In view of the above it should be apparent that embodiments other than those expressly described above come within the spirit and scope of the present invention. Thus, the present invention is not limited by the above-provided description but rather is defined by the claims appended hereto.
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An NBC marker light is designed to be simplistic, lightweight, and expendable. The case is two pieces, designed for ease of assembly. The assembly includes a circuit card, one or more batteries, light sources, typically IR and visible LEDs, and a custom designed rotary switch. A diffuser is designed to enhance side visibility in all directions.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to methods and systems for assembling buckets having a shroud and a tangential entry dovetail onto the rim of a turbine wheel, particularly to assure complete accurate mechanical coupling between adjacent shrouds in final assembly.
[0002] Shrouded turbine buckets, e.g. for use in steam turbines, require the shroud edges to be in mechanical contact with one another, eliminating any gap between adjacent shrouds. The shrouds typically support application of tip seals to provide improved turbine thermal efficiency. High levels of mechanical reliability are also required under service conditions. A shroud having a predominantly rhombic (i.e., full rhombic or modified rhombi) configuration satisfies these design characteristics. Shrouds having a rhombic configuration, however, are not per se new or new in conjunction with buckets employing a tangential entry dovetail. Buckets having rhombic-shaped shrouds have been previously used in low, intermediate and high pressure turbine applications. Integrally shrouded buckets, however, become increasingly difficult to assemble as airfoil stiffness is increased, as airfoil aspect ratio (i.e., radial height/axial width) is reduced, or as higher pre-twist stresses are required. Problems associated with assembly of buckets having rhombic configured shrouds and tangential entry dovetails include; generating adequately high tangential forces needed to eliminate gaps between (i.e., to pack together) adjacent shrouds and dovetail faces, and to produce an adequate pre-twist of the bucket airfoils. The level of pre-twist must be sufficient to assure that the adjacent shrouds remain in contact, i.e. are mechanically coupled, during all normal phases of turbine operation. Tangential assembly forces required to adequately pack buckets together on a turbine wheel can become very high for buckets of the size employed in large steam turbine applications. Also, as the buckets are packed together, the dovetails undergo rotation, which in turn reduces the level of pre-twist applied to the bucket airfoils. Dovetail rotation must be limited to assure an adequate assembly. Further, the buckets in their packed configuration must be constrained from backing away from each other as additional buckets are installed on the wheel. The tendency to back away is associated with the forces developed at the shroud contact surfaces, and the orientation of these surfaces relative to the tangential direction. Accordingly, there is a need for an assembly method and system which will overcome the aforementioned problems associated with assembly of shrouded buckets on a turbine wheel; and which will in turn permit the buckets to meet all efficiency and reliability objectives.
BRIEF DESCRIPTION OF THE INVENTION
[0003] In a preferred embodiment of the present invention, a method of assembling a plurality of buckets on a rotor wheel wherein each bucket includes an airfoil terminating at opposite ends in a shroud and a dovetail, respectively, comprising the step of pre-twisting the shroud and airfoil of each bucket in a rotational direction about a generally radial axis in response to applying a tangential assembly force to interference fit shroud contacting surfaces thereby imparting a rotational bias to the airfoil enabling subsequent rotation of the shroud and airfoil into final assembly with the shroud edges of adjacent buckets in contact with one another and dovetail faces of adjacent buckets in contact with one another.
[0004] In a further preferred embodiment of the present invention, a method of assembling a plurality of buckets on a rotor wheel wherein each bucket includes an airfoil terminating at opposite ends in a shroud and a dovetail, respectively, comprising the steps of: providing a lug on the shroud of each bucket; releasably securing a fixture on each lug carried by the shroud of each bucket, the fixture and lug of respective adjacent buckets having generally complementary tapered surfaces at acute angles relative to the tangential direction; and wedging the fixture carried by the shroud of each bucket being installed against the tapered surface of the lug carried by the shroud of the adjacent bucket previously installed on the rotor rim to pre-twist the shroud and airfoil of the bucket.
[0005] In a further preferred embodiment of the present invention, a turbine wheel and bucket assembly comprising a plurality of buckets each including an airfoil, a shroud adjacent the tip of the airfoil and a dovetail adjacent a root of the airfoil; a lug carried by each shroud; a fixture releasably secured to each lug and having a projection extending in a tangential direction for overlying a portion of a lug of a previously assembled bucket onto the wheel, the adjacent shrouds having interference fit contacting surfaces; at least one of the lug and the fixture projection having a tapered surface in contact with a surface of another of the lug and fixture projection to pre-twist the shroud and airfoil being installed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a fragmentary perspective view illustrating buckets with rhombic-shaped shrouds being installed on the rim of a turbine rotor wheel in accordance with a preferred embodiment of the present invention;
[0007] FIG. 2 is a plan view of a pair of buckets as viewed looking inwardly towards the radially outer faces of the shrouds in the course of assembly of the buckets onto the wheel;
[0008] FIG. 3 is an enlarged fragmentary detail of a portion of FIG. 2 ;
[0009] FIG. 4 is an enlarged view of a fixture for securement to the lug on the shroud;
[0010] FIG. 5 is a view similar to FIG. 2 illustrating a direction of rotation or twist of the shroud and airfoils in the course of the assembly of the buckets on the rotor wheel;
[0011] FIG. 6 is a view similar to FIG. 5 with the fixture removed illustrating a counter-rotation of the shroud and airfoil;
[0012] FIG. 7 is a view similar to FIG. 6 with the buckets in final assembly; and
[0013] FIG. 8 is a fragmentary side elevational view of the shroud and airfoil of the bucket upon final securement.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring now to the drawings, particularly to FIG. 1 , there is illustrated a turbine rotor wheel 10 including a wheel rim 12 having a rib and groove configuration, i.e. a pine tree configuration along opposite axial sides thereof about the circumference of the wheel 10 . Also illustrated in FIG. 1 are a plurality of buckets generally designated 14 . Each bucket 14 includes an airfoil 16 having a dovetail 18 projecting from the root of the airfoil and a shroud 20 adjacent the tip of the airfoil. It will be appreciated that the dovetail 18 has a mating corresponding rib and groove arrangement, i.e., a pine tree configuration complementary to the pine tree configuration of the wheel dovetail 12 . Thus, the buckets 14 constitute tangential entry buckets whereby the buckets are disposed in a radial slot, not shown, on the wheel 10 and slidably disposed about the turbine wheel with contact faces of the dovetail and contact edges of the shrouds in respective engagement with corresponding parts of adjacent buckets. Also illustrated in FIG. 1 is an anti-rotation key 22 which extends about the outer periphery of the dovetail 12 of the rotor wheel 10 and which engages in a corresponding slot at the base of the dovetail 18 to minimize or preclude rotation of the dovetail and hence bucket 14 during assembly and operation. A similar anti-rotation key is described and illustrated in U.S. Pat. No. 5,509,784 of common assignee herewith.
[0015] In FIG. 1 , each of the buckets 14 is illustrated as including a lug 24 projecting radially outwardly from the forward edge of shroud 20 . The lug 24 is preferably formed integrally with the shroud 20 and is in part removed from each bucket and shroud after final assembly. Also illustrated in FIG. 1 are fixtures 26 mounted on each of the respective lugs 24 and which fixtures 26 project axially forwardly. Each fixture 26 may be bolted to an associated lug 24 by bolts 28 .
[0016] As best illustrated in FIG. 2 , the shrouds 20 have a rhombic configuration. It will be appreciated that in final assembly, the angled margins or tangential edges 30 of the shrouds abut one another as illustrated in FIG. 7 . However, those adjoining angled edges 30 which typically extend about 40 to 60° relative to the tangential axis or direction have an extant interference condition at their mating shroud contact surfaces 32 when the buckets are assembled to the turbine wheel and the adjacent dovetail faces 34 contact one another. That is, there is an excess amount of material on the contact edges 30 of the shrouds so that the shroud edges would theoretically overlap one another when the dovetail faces 34 of adjacent buckets 14 are in contact one with the other. Because of this shroud interference condition at the shroud contacting surfaces 32 , the adjacent dovetail faces 34 cannot be brought into full flush contact with one another until a rotation or twisting of the shroud 20 occurs. By rotating the shroud about a bucket radial axis, a change in the shroud cover tangential pitch occurs which permits the bucket assembly to accommodate the shroud interference condition. That is, the excess amount of material forming the edges 30 of the adjacent shrouds is taken up by rotation of the shrouds about generally radial axes of the buckets to produce a twisting of the shrouds as well as an elastic pre-twist of the bucket airfoils. Because of the angle of the shroud edges 30 , a twisting of the shroud reduces the tangential width of the shroud as the shroud rotates about the generally radial axis until all of the interference is taken up. By twisting the shroud, the airfoil acts as a torsional spring, which serves to maintain the contact load between adjacent shroud contact surfaces 32 at all normal operating conditions of the buckets.
[0017] To pre-twist the airfoil during assembly, a substantial tangential assembly force is required to generate the required twisting moment, i.e., torque on the shroud which occurs through the bearing forces on the shroud contact surfaces 32 . The tangential assembly force must also overcome the frictional forces associated with sliding one contact surface 32 relative to the adjacent contact surface 32 .
[0018] In the above referenced U.S. Pat. No. 5,590,784, there is provided shroud contact surfaces having a shallow angle, i.e., approximately 15° relative to the tangential axis creates a wedging effect as the buckets are tangentially assembled. Large bearing forces are thus generated on the shroud contact surfaces for the steep angle design illustrated in that patent and are oriented principally in the axial direction creating a substantial twisting moment on the shroud. The component of the assembly force in the tangential direction, however, is relatively small compared to the axial component of force which minimizes the required tangential assembly force necessary to overcome the tangential component of the shroud force and frictional forces.
[0019] A rhombic configured shroud, however, having a substantially larger tangential axis, i.e., on the order of about 40 to 60°, reduces the wedging action between the shroud contact surfaces as the buckets are driven tangentially causing the required tangential assembly force to be substantially greater than for the steep angle design of the prior patent. This places limitations on the size of bucket that can be adequately assembled.
[0020] In accordance with a preferred embodiment of the present invention, however, the very large interference contact surface angle is accommodated by application of the fixture 26 to the lug 24 . Referring to FIGS. 2 and 3 , each fixture 26 includes a portion 40 which projects in a tangential direction from the lug 24 to which the fixture 26 is attached. The projection 40 includes, on each axial downstream face, a leading chamfer 42 , having an angle Θ of about 10° to the tangential axis and terminating in a flat 44 oriented at about 0° to the tangential axis, as illustrated in FIG. 3 . The flat 44 leads to or terminates in a step 46 in the downstream face of the fixture 26 . The size of step 46 is adjusted based on the interference level at the shroud contact surfaces 32 . Additionally, as seen in FIG. 3 , the axial admission face of the lugs 24 also include a chamfer 48 complementary to the chamfer 42 , the chamfer 48 being located on an adjacent lug to the lug having a registering taper 42 .
[0021] To assemble the buckets on the rim of the rotor wheel, the fixtures 26 are secured to the lugs 24 , e.g. using the bolts 28 . Each successive bucket to be assembled is slid around the wheel rim to a location where the chamfer 42 contacts the mating chamfer 48 on the lug 24 of the preceding bucket. Once contact is made, a tangential assembly force is applied to the bucket being installed to drive the bucket toward the preceding bucket. The fixture 26 thus initially slides along the wedge angle created by the mating chamfers 42 and 48 causing a substantial twisting movement and corresponding rotation to occur at the shroud as illustrated in FIG. 5 as well as a twisting action of the airfoil 16 . It will be appreciated that both of the mating buckets will twist with the application of a tangential assembly force. When the axial step between the faces of the two buckets equals the step size in the fixture, the flat surface 44 of the fixture contacts the flat axially forward face of the shroud lug. The magnitude of rotation at the shroud is governed by the fixture step size and is set to slightly exceed the level of rotation that would naturally be created by the interference condition at the shroud contact surfaces 32 . Thus, as the shroud twists and because of the angle of the shroud edges 30 , the tangential width of the cover as the shroud is rotated is taken up to the extent that the faces of the dovetail surfaces of the buckets contact one another. The step size is set, for example, so that approximately a 0.002 to 0.004 inch gap exists between the edges 30 . This enables the adjacent buckets to slide together to enable the dovetail faces 34 to contact one another with only the involved frictional forces resisting motion of the buckets. Because of the small angle between the fixture 26 and lug 24 , i.e., 10° chamfers and the contact between flat 44 and the adjacent lug, the frictional forces at such contact are larger than the forces tending to drive the buckets apart. The buckets will therefore remain in the partially assembled position after being driven together even when the assembly force is removed. This in turn enables additional buckets to be assembled and likewise driven together without interference from the previously assembled buckets.
[0022] When all of the buckets except for a closure bucket have been applied about the wheel, the closure bucket is inserted into a radial opening in the wheel dovetail and keyed or pinned to adjacent buckets. The assembly fixtures on the shrouds of the closure and adjacent buckets aid in assembly of the closure bucket since a pre-twist of the closure bucket shroud can be applied with the fixtures. Thus, the closure bucket is inserted and driven radially into the notch opening.
[0023] After assembly of the closure bucket, the assembly fixtures 26 are removed from the shrouds. As the fixtures 26 are removed, a rotation of the shrouds occurs in the opposite direction from the initial pre-twist (i.e., compare FIGS. 5 and 6 ). This opposite or negative rotation of the shrouds enables the contact surfaces 32 of the shrouds to come into full flush contact with one another. That is, this counter rotation is provided by the bias of the airfoils 16 from the previously applied pre-twist. It will be appreciated that the dovetail anti-rotation key 22 is in place during assembly of the buckets to constrain dovetail rotation. Thus, the level of pre-twist in the bucket airfoil created by the shroud rotation biases the shroud for rotation in the opposite direction into final assembly. Outer portions 54 of the lugs 24 may then be removed, e.g., by machining, leaving the shrouds 20 including remaining portions of the lugs 24 in final position as illustrated in FIGS. 7 and 8 .
[0024] Referring to FIGS. 5-7 , there is provided a relief groove 50 on the shroud pressure side surface. The relief groove 50 provides a low stress transition between the shroud contact and clearance surfaces. The relief groove 50 is also applied to reduce the potential for fretting fatigue by creating a separation between peak shroud bending and bearing stresses. It also creates a separation between the shroud contact and clearance surfaces such that final machine operations on the more critical shroud contact surface can be performed without impacting the finished clearance surface or corner fillet surfaces.
[0025] 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.
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Rhombic shrouded tangential entry buckets are circumferentially applied to the rotor wheel rim of a turbine. A fixture is releasably secured to a lug on each bucket and includes a chamfered surface for engaging a complementary surface on the lug. Upon applying a tangential assembly force, the shroud and airfoil of adjacent buckets are pre-twisted in a rotational direction about a generally radial axis enabling dovetail faces to contact one another notwithstanding interference fit shroud contacting surfaces. The removal of the fixture from the lug enables the bias of the airfoil to rotate the shroud in an opposite direction into final assembly with the shroud edges of adjacent buckets in contact with one another and the dovetail faces thereof in contact with one another.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 USC 119(e) to Japanese Patent Application No. 2005-032125 filed on Feb. 8, 2005, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a clutch mechanism of a hydrostatic continuously variable transmission. More particularly, the present invention relates to a method for manufacturing a roller bearing member for receiving a pressing force of a roller for a centrifugal type governor clutch of a hydrostatic continuously variable transmission.
2. Description of Background Art
A roller bearing member for a centrifugal governor clutch according to the background art includes a pressure plate for receiving a pressing force of a roller and a shaft for guiding a motion of the pressure plate. In the background art, the centrifugal governor clutch for a hydrostatic continuously variable transmission includes a roller bearing member that has been manufactured such that the pressure plate and the shaft are integrally set. The pressure plate has a plate-like shape and the shaft has a cylindrical shape. Although the machining method should be originally different, the pressure plate and the shaft are integral members. Therefore, the entire member was necessarily manufactured through a cutting operation (refer to JP-A 070331/2004 (FIG. 1), for example). In addition, since the pressure plate is a plate-like member, the machining operation using cutting is difficult.
SUMMARY OF THE INVENTION
An embodiment of the present invention is directed to the structure of a roller bearing member that can be manufactured by a simple machining operation that is suitable for its shape. Therefore, the efficiency of manufacture can be improved to reduce cost.
An embodiment of the present invention can overcome the above-mentioned problems of the background art. Specifically, an embodiment of the present invention is directed to a clutch mechanism for a hydrostatic continuously variable transmission in which a hydraulic circuit comprised of a high pressure oil path for feeding working oil from a hydraulic pump to a hydraulic motor and a low pressure oil path for feeding working oil from said hydraulic motor to said hydraulic pump is constituted between said hydraulic pump and said hydraulic motor, said high pressure oil path and said low pressure oil path are shortened by sliding a clutch valve arranged at a shaft of the transmission through a centrifugal governor to change over a transmittance of power characterized in that the same is comprised of a cam plate member arranged at the end part of said transmission shaft; a roller engaged with said cam plate member and moved outwardly in a diametrical direction by a centrifugal force; a roller bearing member receiving a roller pressing force through outward motion of said roller and slid axially; a spring member for biasing said roller bearing member toward said roller; and said roller bearing member being formed such that a pressure plate and a shaft engaged with said clutch valve and slid are separately formed and integrally formed.
In this embodiment of the present invention, the pressure plate and the shaft are separately formed and the pressure plate can be manufactured efficiently through press forming using a die. In addition, the shaft is not provided with a plate member before it is machined. Therefore, the cutting work performed by a machine can be efficiently carried out. Since both members are welded and integrally formed after their manufacturing, production efficiency is improved.
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
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:
FIG. 1 is a side view of the motorcycle 1 including the power unit 2 of an embodiment of the present invention;
FIG. 2 is a left side view of the power unit 2 mounted in the motorcycle;
FIG. 3 is a cross-sectional cutaway view along lines III-III of FIG. 2 ;
FIG. 4 is a cross-sectional view along IV-IV of FIG. 2 ;
FIG. 5 is a vertical cross-sectional view of the static hydraulic continuously variable transmission T;
FIG. 6 is a cross sectional view of an essential section of the static hydraulic continuously variable transmission T showing the vicinity of the distributor valve 160 ;
FIGS. 7( a ) and 7 ( b ) are views of the cotter pin 151 , wherein FIG. 7( a ) is a front view and FIG. 7( b ) is a cross-sectional view along line 7 ( b )- 7 ( b ) of FIG. 7( a );
FIGS. 8( a ) and 8 ( b ) are views of the retainer ring 152 , wherein FIG. 8( a ) is a front view and FIG. 8( b ) is a cross-sectional view along line 8 ( b )- 8 ( b ) of FIG. 8( a );
FIGS. 9( a ) and 9 ( b ) are views of the C clip 153 , wherein FIG. 9( a ) is a front view and FIG. 9( b ) is a cross-sectional view along line 9 ( b )- 9 ( b ) of FIG. 9( a );
FIG. 10 is a vertical cross-sectional view of an essential section of the static hydraulic continuously variable transmission T showing the vicinity of the centrifugal governor clutch C; and
FIG. 11 is a vertical cross-sectional view of an essential section of the static hydraulic continuously variable transmission T showing the supply passages for the operating fluid and the lubricant fluid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a side view of the motorcycle 1 containing the power unit 2 of an embodiment of the present invention. The motorcycle 1 includes a pair of main frames 4 that connect to a head pipe 3 and slope downwards to the rear. A pair of sub frames 5 slope downwards from the lower section of the head pipe 3 and bend rearwards. Respective rear tips of the sub frames connect to the rear end of the main frame 4 .
A power unit 2 that includes an internal combustion engine 6 and a transmission 7 is mounted in a generally triangular space formed by the main frame 4 and the sub frame 5 as seen from the side. A front fork 8 is supported to allow rotation in the head pipe 3 . The steering handle 9 is mounted on the top end of the front fork 8 . A front wheel 10 is axially supported by a bottom end of the front fork 8 . A pair of rear forks 11 are supported on their forward end by the rear section of the main frame 4 and are capable of swinging upward and downward. A rear suspension (not shown in drawing) is mounted between the rear end of the main frame 4 and the center section of the rear fork 11 . A rear wheel 12 is axially supported on the rear end of the rear forks 11 .
The internal combustion engine 6 is a water-cooled V-type two-cylinder combustion engine with the cylinders opening in a V-shape towards the front and rear. The crankshaft of the internal combustion engine 6 is perpendicular to the forward direction of the vehicle, and is installed facing towards the left and right of the vehicle. The transmission shaft of the transmission 7 is parallel to the crankshaft. The rear wheel drive shaft (not shown in the drawings) is connected to the connecting shaft 85 ( FIG. 2 ) perpendicular to the output shaft of the transmission, and extends rearward of the vehicle, reaching and driving the rotating shaft of the rear wheel 12 .
An exhaust pipe 13 is connected to the exhaust port and is installed facing the front and rear of the two vehicle cylinders. The exhaust pipe 13 extends forwards of the internal combustion engine 6 , and extends under the transmission 7 to the frame rear section. The exhaust pipe 13 connects to the exhaust muffler 14 . A fuel tank 17 is mounted on the upper section of the (main) frame 4 , and a seat 18 is mounted to the rear. The internal combustion engine 6 is a water-cooled type. Cooling water having a temperature that rises during the process of cooling the cylinder and oil is cooled in the radiator 19 installed on the front end of the sub frame 5 .
FIG. 2 is a left-side view of the power unit 2 mounted on the motorcycle. The arrow F indicates the front during installation in the frame. The front side cylinder 24 F and the rear side cylinder 24 R possess the same internal structure so the cross-section of only the rear side cylinder 24 R is shown. The crankcase rear section shows the state with the left crankcase cover removed and shows the positions of the main internal rotating shafts and gears and sprockets.
FIG. 3 is a cross sectional view taken along lines III-III of FIG. 2 . This figure is a cross sectional view including the rear side cylinder 24 R and the crank shaft 30 and the transmission shaft 100 of the static hydraulic continuously variable transmission T. The rear side cylinder 24 R is a cylinder holding the piston 33 connecting to the left side crankpin 31 .
The main components of the power unit 20 in FIG. 2 and FIG. 3 are the crankcase 20 comprised of a left crankcase 20 L and a right crankcase 20 R, a left crankcase cover 21 L, a right crankcase cover 21 R, and a cylinder block 25 , a cylinder head 26 and a cylinder head cover 27 respectively installed with the front side cylinder 24 F and the rear side cylinder 24 R. The following description of the cylinder sections is based on the rear cylinder 24 R.
In FIG. 3 , the crankshaft 30 is supported to allow free rotation by the left side bearing 28 and the right side bearing 29 held in the left/right crankcases 20 L and 20 R. A connecting rod 32 and a piston 33 are connected to the left side crankpin 31 on the crankshaft 30 . The piston 33 is held to allow sliding movement in the cylinder hole 34 of the cylinder block 25 . A combustion chamber 35 is formed in the section facing the piston 33 of the cylinder head 26 . A spark plug 36 is inserted through the wall of the cylinder head 26 . A tip of the spark plug enters the combustion chamber 35 and a rear end of the spark plug is exposed externally.
In FIG. 2 , an exhaust port 40 and an intake port 41 are connected to the combustion chamber 35 . The exhaust port 40 extends forwards in the front side cylinder 24 , and rearward in the rear side cylinder 24 R. The intake port 41 extends upwards for either cylinder in the space between both cylinders. The exhaust port 40 contains an exhaust valve 42 , and the intake port 41 contains an intake valve 43 . A camshaft 44 is installed inside the cylinder head cover 27 . An exhaust rocker arm shaft 45 , and an intake rocker arm shaft 46 are installed above the camshaft 44 . The exhaust rocker arm 47 and the intake rocker arm 46 installed on these arm shafts are driven by the cam 44 a , 44 b of the camshaft 44 . The exhaust rocker arm 47 and the intake rocker arm 46 press the stems of the intake valve 43 and the exhaust valve 42 to drive each valve to open or close. In FIG. 3 , the camshaft 44 is driven by a camshaft drive chain 51 hooked on the camshaft drive sprocket 50 installed in the crankshaft 30 and the camshaft auxiliary sprocket 49 installed on the end of the camshaft 44 .
In FIG. 2 , a low-pressure oil pump and a high-pressure oil pump are integrated via an oil pump shaft 91 into an oil pump cluster 90 , at a lower section of the crankcase 20 . The low-pressure oil pump feeds oil towards the internal combustion engine 6 , and the high-pressure oil pump feeds oil towards the static hydraulic continuously variable transmission T. The oil pump cluster 90 suctions oil within the oil pan 92 by way of the lower section oil strainer 93 . The internal combustion engine 6 drives the oil pump cluster 90 via an oil pump drive chain 96 engaged on the oil pump shaft drive sprocket 95 installed in the crankshaft 30 , and the oil pump auxiliary drive sprocket 94 inserted into the oil pump shaft 91 . An oil cooler 97 and a low-pressure oil filter 98 can be seen on the rear section of the crankcase 20 . The high-pressure oil filter is installed on the right side of the crankcase and is therefore not shown in the drawing.
In FIG. 3 , the crankshaft output gear 37 that is installed on the left end of the crankshaft 30 functions as a gear in combination with the cam type torque damper 38 . The crankshaft output gear 37 engages with the transmission input gear 116 installed on the casing 110 of the tilt plate plunger-type hydraulic pump P of the static hydraulic continuously variable transmission T. The crankshaft output gear 37 and the cam type torque damper 38 are installed on a collar 60 that is spline-coupled to the crankshaft 30 . The crankshaft output gear 37 is mounted for free rotation on the collar 60 . A recessed cam 37 a with a concave surface in an arc-shape is formed on a side surface of the crankshaft output gear 37 . A lifter 61 is inserted on the outer circumferential spline of the collar 60 to allow axial movement. A protruding cam 61 a with an arc-shaped protruding surface is formed on the edge of the lifter 61 . The protruding cam 61 a engages with the recessed cam 37 a . A spring holder 62 is fastened to the edge of the collar 60 with a spline and cotter pin. A flat spring 63 is installed between the spring holder 62 and the lifter 61 . The flat spring 63 forces the protruding cam 61 a towards the recessed cam 37 a.
During operation at a fixed speed, the torque of the crank shaft 30 is transferred in sequence to the collar 60 , the lifter 61 , the protruding cam 61 a , the recessed cam 37 a , and the crankshaft output gear 37 . The crankshaft output gear 37 rotates along with the crankshaft 30 . When excessive torque is applied to the crankshaft 30 , the protruding cam 61 a slides along the circumference of the cam surface of the recessed cam 37 a , and moves axially opposing the force of the flat spring 63 , absorbing the huge torque and alleviating the impact.
The crankshaft output gear 37 is a gear for reducing backlash. The crankshaft output gear 37 is comprised of a thick, main gear 64 in the center, and a thin auxiliary gear 65 supported to allow concentric rotation versus the main gear 64 , and an auxiliary gear coil spring 66 for applying a peripheral force via the auxiliary gear 65 on the main gear 64 . The auxiliary gear applies a circumferential (peripheral) force to eliminate the backlash gap that occurs between the main gear and the normal gear, when the backlash reducing gear engages with a normal gear and so can eliminate looseness (play) and alleviate noise to quiet the mechanism. In the present case, the noise from the crankshaft output gear 37 engaging with the transmission input gear 116 is reduced.
In FIG. 3 , the static hydraulic continuously variable transmission T is installed rearward of the crankshaft 30 . The static hydraulic continuously variable transmission T is a device combining a centrifugal governor clutch C, a tilt plate plunger-type hydraulic pump P, and tilt plate hydraulic motor M via the motor transmission shaft 100 . When the rotation speed of the casing 110 of the tilt plate plunger-type hydraulic pump P exceeds a specified speed, the transmission input gear 116 connects (engages) the static hydraulic continuously variable transmission T due to the centrifugal force effect of the governor clutch C to change the speed. The static hydraulic continuously variable transmission T changes the speed by changing the speed (gear) ratio according to the tilted state of the tilt plate for the tilt plate hydraulic motor M. The rotational force for the change in speed is extracted from the motor transmission shaft 100 that rotates as one piece with the hydraulic pump P and the hydraulic motor M. A motor servomechanism changes the tilt angle of the tilt plate of the tilt plate hydraulic motor M. The structure and effect of the static hydraulic continuously variable transmission T will be described below.
FIG. 4 is a cross-sectional view taken along lines IV-IV in FIG. 2 . This is the path for transmitting power from the transmission shaft 100 to the connecting shaft 85 . A neutral-drive selector shaft 76 for the neutral-drive selector clutch 75 for selecting the neutral and drive states, and in parallel with the transmission shaft 100 , is supported via ball bearings in the right crankcase 20 R and the left crankcase 20 L to allow rotation. An output shaft 80 in parallel with the neutral-drive selector shaft 76 is supported via ball bearings in the right crankcase 20 R and the right crankcase cover 21 R to allow rotation. Furthermore, the connecting shaft 85 perpendicular to the output shaft 80 is supported by the connecting shaft support section 84 installed near the left edge of the output shaft 80 to allow rotation. The connecting shaft support section 84 is installed on the outer side of the left crankcase 20 L (Also see FIG. 2 .).
In FIG. 4 , a gear 68 is clamped to the transmission shaft 100 . A gear 77 is inserted into the neutral-drive selector shaft 76 to allow rotation versus the shaft. The gear 77 engages with the transmission output gear 68 affixed to the transmission 100 . The swing member 78 including a mesh gear 78 a and adjacently connected to the gear 77 is inserted to allow sliding axially to the neutral-drive selector shaft 76 . The neutral-drive selector clutch 75 includes the neutral-drive selector shaft 76 , the gear 77 , and a swing member 78 ; and cuts off or connects the drive power conveyed from the transmission drive shaft 100 to the output shaft 80 . When the mesh gear 78 a of swing member 78 releases from the gear 77 , the neutral-drive selector clutch 75 sets a neutral state, and slides the swing member 78 . When the mesh gear 78 a engages with the mesh section of the gear 77 , the drive power transmission path is connected, and the drive state is set.
In FIG. 4 , a gear 79 is inserted on the neutral-drive selector shaft 76 and adjacently contacts the gear 77 on the opposite side of the slide member 78 . A gear 81 is inserted on the right end of the output shaft 80 to engage with the gear 79 on the neutral-drive selector shaft 76 . A bevel gear 82 is formed as one piece with the other end of the output shaft 80 . A bevel gear 86 is formed as one piece on the front end of the connecting shaft 85 , and engages with the bevel gear 82 of the output shaft 80 . A spline 85 a is mounted on the rear end of the connecting shaft 85 for connection to the rear wheel drive shaft. The rotational output power of the static hydraulic continuously variable transmission T is transmitted to the rear wheel transmission shaft by way of these shafts and gears.
FIG. 5 is a vertical cross-sectional view of the static hydraulic continuously variable transmission T. The static hydraulic continuously variable transmission T is made up of a tilt plate plunger-type hydraulic pump P, a tilt plate plunger-type hydraulic motor M, and a centrifugal governor clutch C. The transmission shaft 100 functioning as the output shaft for the static hydraulic continuously variable transmission T is mounted to pass through the center (of transmission T). The left end of the transmission shaft 100 is supported to allow rotation by the ball bearings B 1 , B 2 on the left crankcase cover 21 L, and the right end is supported to allow rotation by the ball bearing B 3 on the right crankcase 20 R.
The hydraulic pump P includes a pump casing 110 capable of rotating relative to the transmission shaft 100 and installed concentrically with it; a pump tilt plate 111 installed tilted at a specific angle versus the rotating shaft of the pump casing in the interior of the pump casing 110 , and a pump cylinder 112 installed facing this same pump tilt plate 111 ; and multiple pump plungers 114 installed to slide within the pump plunger holes 113 arrayed in a ring shape enclosing the shaft center within the pump cylinder 112 . One end of the pump casing 110 is supported to allow rotation by the bearing B 2 in the transmission shaft 100 , and the other end is supported to allow rotation by the bearing B 4 in the pump cylinder 112 , and also supported to allow rotation by the bearing B 1 in the left crankcase cover 21 L. The pump tilt plate 111 is installed tilted at a specified angle to allow rotation relative to the pump casing 110 by the bearings B 5 , B 6 .
The transmission input gear 116 affixed by the bolt 115 is installed on the outer circumference of the pump casing 110 . The outer end of the pump plunger 114 engages with the tilt plate surface 111 a of the pump tilt plate 111 protruding outwards. The inner edge of the pump plunger 114 forms a pump fluid chamber 113 a in the pump plunger hole 113 . A pump passage opening 117 functioning as a dispensing hole and an intake hole is formed on the edge of the pump plunger hole 113 . The pump casing 110 rotates when the transmission input gear 116 is made to rotate. The pump tilt plate 111 installed inside slides along with the rotation of the pump casing 110 . The pump plunger 114 moves back and forth within the pump plunger hole 113 according to the swing of the tilt plate surface 111 a . The hydraulic fluid within the pump fluid chamber 113 a is dispensed and suctioned.
The pump eccentric ring member 118 is installed by a bolt 119 on the right edge of the pump casing 110 in the center of the drawing. The inner circumferential surface 118 a of the pump eccentric ring member 118 is formed in a tubular shape that is off-center versus the rotating shaft of the pump casing 110 . Therefore, this inner circumferential surface 118 a is also a tubular shaped offset in the same way versus the center line of the transmission shaft 100 and the pump cylinder 112 .
The casing 130 of the hydraulic motor M is affixed and supported while clamped to the right crankcase 20 R. The motor casing 130 is formed from the spherical member 131 and the elongated member 132 , and is clamped by the bolt 133 . A support spherical surface 131 a is formed on the inner surface of the spherical member 131 . The hydraulic motor M is comprised of a motor casing 130 , and a motor swing member 134 that is slide connected and supported on the support spherical surface 131 a . A motor tilt plate 135 is supported to allow rotation by the bearings B 7 , B 8 within the motor swing member 134 . A motor cylinder 136 faces the motor tilt plate 135 . A motor plunger 138 is installed to allow sliding within the multiple plunger holes 137 passing through in the axial direction and arrayed in a ring shape enclosing the center axis of the motor cylinder 136 . The motor cylinder is supported for rotation along the external circumference in the elongated member 132 of the motor casing 130 by way of the bearing B 9 . The motor swing member 134 is capable of swinging in a movement centering on the center O extending at a right angle (direction perpendicular to the paper surface) to the center line of the transmission shaft 100 .
The outer side edge of the motor plunger 138 engages with the tilt plate surface 135 a of the motor tilt plate 135 protruding outwards. The inner side edge of the motor plunger 138 forms a motor fluid chamber 137 a within the motor plunger hole 137 . A motor passage opening 139 functioning as an intake port and a dispensing (exhaust) port for the motor is formed in the edge of the motor plunger hole 137 . The edge of the motor swing member 134 is formed as an arm 134 a protruding to the outer side and protrudes outwards towards the radius to connect to the motor servo mechanism S. The arm 134 a is controlled by the motor servo mechanism S to move left and right, and is controlled to swing centering on the swing center O of the motor swing member 134 . When the motor swing member 134 swings, the motor tilt plate 135 supported internally inside it ( 134 ) also swings, and changes the angle of the tilt plate.
FIG. 6 is an enlarged cross-sectional view of the vicinity of the distributor valve 160 of the static hydraulic continuously variable transmission T. The distributor valve 160 is installed between the pump cylinder 112 and the motor cylinder 136 . The valve body 161 of the distributor valve 160 is supported between the pump cylinder 112 and the motor cylinder 136 , and is integrated with these cylinders by brazing. The motor cylinder 136 is coupled to the transmission shaft 100 by a spline 101 . The pump cylinder 112 , the distributor valve 160 , and the motor cylinder 136 rotate with the transmission shaft 100 as one unit. This integrated pump cylinder 112 , valve body 161 of the distributor valve 160 , and the motor cylinder 136 are called the output rotation piece R. The structure for attaching the output rotation piece R to the transmission shaft will now be described. A large diameter section 102 that is short along the axial length is formed on the outer circumferential side of the transmission shaft 100 corresponding to the left edge position of the pump cylinder. The left edge surface of the pump cylinder 112 contacts the edge surface of this large diameter section 102 , to perform positioning to the left.
The right side positioning of the output rotation piece R, is performed by the stop member 150 installed on the transmission shaft 100 facing the motor cylinder 136 . The stop member 150 includes a cotter pin 151 , a retainer ring 152 , and a C ring 153 . To install the stop member 150 , a ring-shaped first stop groove 103 , and second stop groove 104 are formed across the outer circumference of the spline 101 . A pair of cotter pins 151 is separately formed in a semicircular shape shown in FIG. 7 and is installed in the first stop groove 103 . A retainer ring 152 is installed above it as shown in FIG. 8 . The tip section 152 a of the retainer ring 152 covers the outer circumferential surface of the cotter pin 151 , and the inward facing flange 152 b of retainer ring 152 contacts the side surface of the cotter pin. Moreover, the C ring 153 is installed as shown in FIG. 9 in the second stop groove 104 , and prevents the retainer ring 152 from coming loose. As a result of the above, the right edge surface of the motor cylinder 136 directly contacts the stop piece 150 and is positioned towards the right.
The output rotation piece R is in this way positioned to the left by the large diameter piece 102 via the spline 101 ; and positioned to the right versus the transmission shaft 100 by the stop piece 150 and rotates along with the transmission shaft 100 as one piece. A lubricating oil injection nozzle 152 e connecting the outer tilt plate 152 d and the inner circumferential ring groove 152 c of the retainer ring 152 is drilled as three sections along the entire circumference.
In FIG. 6 , the multiple pump side valve holes 162 and motor side valve holes 163 extending towards the diameter and positioned at equal spaces along the periphery within the valve body 161 forming the distributor valve 160 , are formed in an array of two rows. A pump side switcher valve 164 is installed within the pump side valve hole 162 , and a motor side switcher valve 165 is installed within the motor side valve hole 163 and each ( 164 , 165 ) is capable of sliding movement.
The multiple pump side valve holes 162 are formed to correspond to the pump plunger holes 113 . Each of the pump side valve holes 162 , and pump flow passages 117 formed in the inner side edge of the pump plunger holes 113 , and the multiple pump side connecting passages 166 formed to respectively connect to them ( 162 , 117 ), are formed in the valve body 161 . The motor side valve holes 163 are formed to correspond to the motor plunger holes 137 . The motor connecting passages 139 formed on the inner edge side of the motor plunger holes 137 . The motor connecting passages 167 connecting with the respective motor side valve holes 163 are formed in the valve body 161 .
A pump side cam ring 168 is installed at a position enclosing the outer circumferential edge of the pump side switcher valve 164 on the distributor valve 160 . A motor side cam ring 169 is installed at a position enclosing the outer circumferential edge of the motor side switcher valve 165 on the distributor valve 160 . The pump side cam ring 168 is installed onto the inner circumferential surface 118 a of pump eccentric ring member 118 clamped by a bolt 119 to the tip of the pump casing 110 ( FIG. 5 ). The motor cam ring 169 is installed onto the inner circumferential surface 140 a of the motor eccentric ring member 140 positioned in contact with the tip of the elongated member 132 of motor casing 130 ( FIG. 5 ). The outer side edge of the pump side switcher valve 164 on the inner circumferential surface of the pump side cam ring 168 is engaged to allow sliding movement via the pump side restrictor ring 170 . The outer side edge of the motor side switcher valve 165 on the inner circumferential surface of the motor side cam ring 169 is engaged to allow sliding movement via the motor side restrictor ring 171 . The cam ring and the restrictor ring are both capable of relative rotation on either the pump side or the motor side.
A ring-shaped recess functioning as the inner side passage 172 is carved onto the outer circumferential surface of the transmission shaft 100 facing the inner circumferential surface of the valve body 161 . The inner edge of the motor side valve hole 163 and the pump side valve hole 162 are connected to this inner side passage 172 . An outer side passage 173 is formed near the external circumference of the valve body 161 to connect with the pump side valve hole 162 and motor side valve hole 163 .
The operation of the distributor valve 160 will now be described. When the drive force of the internal combustion engine is conveyed to the transmission input gear 116 and the pump casing 110 rotates, the pump tilt plate 111 swings according to that rotation. The pump plunger 114 engaging with the tilt plate surface 111 a of the pump tilt plate 111 moves axially back and forth within the pump plunger hole 113 by way of the swinging of the pump tilt plate 111 . Hydraulic fluid is dispensed via the pump passage opening 117 from the pump fluid chamber 113 a during inward movement of the pump plunger 113 , and hydraulic fluid is suctioned into the pump fluid chamber 113 a via the pump passage opening 117 during outward movement.
At this time, the pump side cam ring 168 installed on the inner circumferential surface 118 of the pump eccentric ring member 118 coupled to the edge of the pump casing 110 , rotates along with the pump casing 110 . The pump side cam ring 168 is offset (eccentric) versus the rotation center of the pump casing 110 . In other words, it is installed offset (eccentric) to the valve body so that the pump side switcher valve 164 moves back and forth along the diameter within the pump side valve hole 112 , according to the rotations of the pump side cam ring 168 .
The pump side switcher valve 164 moves back and forth in this way, and when moving inwards along the diameter within the valve body 161 , the pump side connecting passage 166 opens outwards along the diameter via a small diameter section 164 a of the pump side switcher valve 164 , and connects the pump passage opening 117 and the outer side passage 173 . When the pump side switcher valve 164 moves outward along the diameter within the valve body 161 , the pump side connecting passage 166 opens inwards along the diameter, and connects the pump passage opening 117 and the inner side passage 172 .
The pump tilt plate 111 swings along with the rotation of the pump casing 110 , the pump side cam ring 168 moves the pump side switcher valve 164 back and forth along the diameter, to match the position (lower dead point) where the pump plunger 114 is pressed farthest to the outside, and the position (upper dead point) where furthermost to the inside during its back and forth movement. The pump plunger 114 consequently moves from the lower dead point to the upper dead point along with the rotation of the pump casing 110 , and the hydraulic fluid within the pump fluid chamber 113 a is dispensed from the pump passage opening 117 . The pump passage opening 117 at this time is connected to the outer side passage 173 so that the hydraulic fluid is sent to the outer side passage 173 . On the other hand, when the pump plunger 114 moves from the upper dead point to the lower dead point along with the rotation of the pump casing 110 , the hydraulic fluid within the inner side passage 172 is suctioned inside the pump fluid chamber 113 a via the pump passage opening 117 . In other words, when the pump casing 110 is driven, hydraulic fluid is dispensed from a pump fluid chamber 113 a on one side and supplied to the outer side passage 173 , and hydraulic fluid is suctioned from the inner side passage 172 into the pump fluid chamber 113 a on the other side of the transmission shaft 100 .
However, the motor side cam ring 169 installed on the inner circumferential surface 140 a of the motor ring eccentric member 140 positioned in sliding contact on the edge of the motor casing 130 , is positioned eccentrically versus the rotation center of the transmission shaft 100 and the output rotation piece R, and motor cylinder 136 , when the motor ring eccentric member 140 is in the usual position, When the motor cylinder 136 rotates, the motor side switcher valve 165 moves back and forth along the diameter within the motor side valve hole 163 according to that ( 136 ) rotation.
When the motor side switching valve 165 moves inwards along the diameter within the valve body 161 , the small diameter section 165 a of the motor side switching valve 165 opens the motor side connection path 167 to the outside, connecting the motor passage opening 139 and the outer side passage 173 . When the motor side switching valve 165 moves outward along the diameter within the valve body 161 , the motor side connection path 167 opens inwards along the diameter, connecting the motor passage opening 139 and the inner side passage 172 .
The hydraulic fluid dispensed from the hydraulic pump P is sent to the outer side passage 173 , and this hydraulic fluid is supplied via the motor side connection path 167 , and the motor passage opening 139 to inside the motor fluid chamber 137 a , and the motor plunger 138 is pressed axially outward. The outer edge of the motor plunger 138 is configured to slide-contact to the section where the motor tilt plate 135 moves from the upper dead point to the lower dead point. Due to this force pressing axially outwards, the motor plunger 138 moves along with the motor tilt plate 135 , along the tilted surface formed by the motor sliding member 134 and the bearing B 7 , B 8 . The motor cylinder 136 is consequently pressed by the plunger 138 and driven. Along with the rotation of the motor cylinder 136 , the motor side cam ring 169 makes the motor side switching valve 165 move back and forth along the diameter in the valve body 161 , corresponding to the back and forth movement of the motor plunger 138 .
The motor cylinder 136 on the opposite side moves the periphery of the transmission shaft 100 along with the rotation of the motor tilt plate 135 centering on the transmission shaft 100 , moving from the lower dead point to the upper dead point. The hydraulic fluid within the motor fluid chamber 137 a is sent from the motor passage opening 139 to the inner side passage 172 , and is suctioned via the pump side connecting passages 166 and pump passage opening 117 .
A hydraulic shut off circuit joining the tilt plate hydraulic motor M and the tilt plate plunger-type hydraulic pump P is in this way formed by the distributor valve 160 . The hydraulic fluid dispensed according to the rotations of the hydraulic pump P is sent to the hydraulic motor M via the other hydraulic shut-off circuit (outer side passage 173 ), driving it. Moreover, the hydraulic fluid dispensed along with the rotation of the hydraulic motor M is returned to the hydraulic pump P via the other hydraulic shut-off circuit (inner side passage 172 ).
In the static hydraulic continuously variable transmission T described above, the hydraulic pump P is driven by the internal combustion engine 6 , the rotation drive power of the hydraulic motor M is converted by the distributor valve 160 and the hydraulic motor M, extracted from the transmission shaft 100 , and transmitted to the vehicle wheels. When the vehicle is being driven, the outer side passage 173 is the high pressure side fluid path, and the inner side passage 172 is the low pressure side. On the other hand, during times such as driving downhill, the drive force for the vehicle wheels is transmitted from the transmission shaft 100 to the hydraulic motor M, and the rotational drive force of the hydraulic motor P renders the effect of an engine brake conveyed to the internal combustion engine 6 , the inner side passage 172 is the high pressure side fluid path, and the outer side passage 173 is the low pressure side fluid path.
The gear ratio of the static hydraulic continuously variable transmission T can be continuously changed by varying the tilt angle of the motor swing member 134 . The tilt angle of the motor swing member 134 is changed for a motor tilt plate angle of zero or in other words, when the motor tilt plate is perpendicular to the transmission shaft, the top gear ratio is reached, the amount of offset (eccentricity) of the eccentric (ring) member 140 reaches zero due to the effect of the lockup actuator A ( FIG. 5 ), the center of the motor cylinder 136 matches the center of the eccentric member 140 , and the pump casing 110 , the pump cylinder 112 , the motor cylinder 136 , and the transmission shaft 100 rotates as one unit to efficiently transfer the drive power.
FIG. 10 is a vertical cross-sectional view of the vicinity of the centrifugal governor clutch C. When the inner side passage 172 and the outer side passage 173 are connected in the static hydraulic continuously variable transmission T, the high hydraulic pressure is no longer applied, and drive power is no longer transmitted between the hydraulic pump P and the hydraulic motor M. In other words, clutch control is implemented by controlling the degree of opening of the connection between the inner side passage 172 and the outer side passage 173 .
The centrifugal governor clutch C includes a spring sheet member 182 and a cam plate member 181 clamped by a bolt 180 to the edge of the pump casing 110 . A roller 183 is held respectively within the multiple cam plate grooves 181 a formed extending diagonally along the diameter on the inner surface of the cam plate member 181 . A pressure plate 184 includes an arm section 184 a facing the cam plate groove 181 a . A coil spring 185 has one end supported by the spring sheet member 182 and the other end acting on the pressure plate 184 for making the arm section 184 a of the pressure plate 184 apply a pressing force on the inside of the groove 181 a . A slide shaft 186 slides along the axial line of the transmission shaft and is inserted into the center hole 181 b of the cam plate member 181 and also passes through the center section of the pressure plate 184 . A rod-shaped clutch valve 187 is engaged with the clutch valve engage section 186 a of the slide shaft 186 . One end of the coil spring 185 is supported by the spring sheet 182 a formed on the inner-facing flange of the spring sheet member 182 . The pressure plate 184 and the slide shaft 186 are both fabricated as separate pieces, and then coupled into a single piece to comprise the roller bearing member 188 . The pressure plate 184 is fabricated by forming it in a press, and the slide shaft 186 fabricated by cutting with machining tools and both parts are then welded together into one piece.
When the pump casing 110 is in a static state, or in other words a state where neither the cam plate member 181 or the spring sheet member 182 are rotating, the arm section 184 a presses the roller 183 into the cam plate groove 181 a by the pressing force applied to the pressure plate 184 by the coil spring 185 . The cam plate groove 181 a is in a tilted state so that the roller 183 is pressed along the diameter of the cam plate member 181 , and the pressure plate 184 , and the swing axis 186 integrated with it, and the rod clutch valve 187 engaged in the swing shaft 186 are in a state shifted to the left.
When the pump casing 110 is driven by the rotation of the transmission input gear 116 ( FIG. 5 ), and the cam plate 181 and the spring sheet member 182 rotate, the roller 183 is pressed back along the tilted surface of the cam plate member 181 outwards along the diameter by centrifugal force, and presses the arm section 184 a to the right and the pressure plate 184 moves to the right while opposing the force of the coil spring 185 . The amount of movement towards the right of the pressure plate 184 and the slide shaft 186 functioning as one piece with it are determined by the centrifugal force acting on the roller 183 . In other words, it (amount of movement) is determined according to the rotational speed of the pump casing 110 . When the rotational speed of the pump casing 110 increases, the rod clutch valve 187 engaged in the slide shaft 186 , extends along the inner section of the transmission shaft 100 , and shifts to the inner part of the clutch valve hole 105 . The centrifugal governor mechanism is in this way configured to apply a centrifugal force to the roller 183 by utilizing the centrifugal force from the rotation of the pump casing.
An inner side connecting fluid path 190 is formed in the transmission shaft 100 as shown in FIG. 10 that joins the clutch valve hole 105 and the inner side passage 172 . An outer side connecting fluid path 191 joining the clutch valve hole 105 and an outer side passage 173 , and a ring-shaped groove 192 and a tilt fluid path 193 for a short connection are formed in the transmission shaft 100 and the pump cylinder 112 . When the pump casing 110 is in a static state, the inner side connecting fluid path 190 and the outer side connecting fluid path 191 are connected by way of the small diameter section 187 a of the rod-shaped clutch valve 187 , and consequently the inner side passage 172 and outer side passage 173 are connected so the clutch is disengaged.
When the pump casing rotation exceeds the specified speed, and the rod-shaped clutch valve 187 shifts to the innermost section of the clutch valve hole 105 due to effect of centrifugal force from the governor mechanism, the small diameter section 187 a of the rod-shaped clutch valve 187 releases (away) from the opening on the clutch valve hole 105 side of the outer side connecting fluid path 191 , and the outer side connecting fluid path 191 opening is blocked by the large diameter side surface 187 b of rod-shaped clutch valve 187 (See position of rod-shaped clutch valve 187 in FIG. 6 .). The connection between the inner side passage 172 and outer side passage 173 is therefore blocked and an oil circulation shut-off circuit is formed from the hydraulic pump P and outer side passage 173 and hydraulic motor M and inner side passage 172 , and the static hydraulic continuously variable transmission T functions. Switching from a clutch released state to a clutch engaged state is performed by the roller so that the clutch gradually becomes engaged (connected) according to this movement.
FIG. 11 is a vertical cross sectional view of an essential section of the static hydraulic continuously variable transmission T showing the supply path for the lubricant fluid and the operating (hydraulic) fluid. The operating (hydraulic) fluid is supplied from the high-pressure oil pump of the oil pump cluster 90 driven by the internal combustion engine, via the fluid path within the crankcase, from the right end, to the transmission shaft center fluid path 200 formed along the axis and in the center of the transmission shaft 100 . The innermost section of the transmission shaft center fluid path 200 is joined to the fluid path 201 extending along the diameter to the outer circumference. The fluid path 201 is also joined with the output rotation piece inner fluid path 202 formed in parallel with the transmission shaft 100 within the output rotation piece R (motor cylinder 136 , valve body 161 , pump cylinder 112 ) that rotates as one piece with the transmission shaft 100 . The output rotation piece inner fluid path 202 is a fluid path including the fluid path 202 a within the motor cylinder 136 , the fluid path 202 b within the valve body 161 , and the fluid path 202 c within the pump cylinder 112 .
A check valve 210 for supplying replacement fluid within the outer side passage 173 is installed within the pump cylinder 112 . The output rotation piece inner fluid path 202 is joined to the check valve 210 via the fluid path 203 facing outwards along the diameter in the innermost section ( 202 ), and if necessary (according to leakage of operating fluid from the hydraulic shut-off circuit), operating fluid is supplied to the outer side passage 173 of the valve body 161 . A check valve and fluid path for supplying operation fluid to the inner side passage 172 are installed in the same way in another section of the pump cylinder 112 , and if necessary also supply operating fluid to the inner side passage 172 (omitted from drawing).
An outer ring groove 204 is formed on the outer circumference of the transmission shaft 100 corresponding to the innermost section of the output rotation piece inner fluid path 202 , and connects to the innermost section of the output rotation piece inner fluid path 202 . An inner ring groove 205 is formed on the inner circumference of the clutch valve hole 105 of the transmission shaft 100 , and connects to the outer ring groove 204 at one location via the connecting fluid path 206 . An orifice 206 a is formed in the connecting fluid path 206 . On the transmission shaft 100 , a lubricant oil injection nozzle 207 connecting to the inner ring groove 205 of the clutch valve hole and facing the external circumference of the transmission shaft 100 is drilled at three locations on the transmission shaft periphery. A portion of the oil supplied within the output rotation piece inner fluid path 202 is injected by way of the lubricant oil injection nozzle 207 , and the outer ring groove 204 , the connecting fluid path 206 , the inner ring groove 205 , and lubricates the pump tilt plate 111 , etc.
A fluid path 208 is formed at one location from the transmission shaft center fluid path 200 along the diameter, facing towards the stop member 150 on the right edge positioner section of the output rotation piece R on the transmission shaft 100 , and an orifice 208 a is formed on its inner edge section. The outer edge section of the fluid path 208 connects along the diameter to the ring groove 152 c formed on the inner circumference of the retainer 152 . A portion of the oil supplied to inside the transmission shaft fluid path 200 is supplied via the fluid path 208 and the inner ring groove 152 c , to the lubricant oil injection nozzle 152 e formed at three locations on the periphery of the inner ring groove 152 c and the outer tilt plate 152 d of the retainer ring 152 ; and is dispensed from the lubricant oil injection nozzle 152 e and lubricates the motor tilt plate 135 , etc.
The distance L 1 between the inner edge surface 113 b of the pump plunger hole 113 and the pump side edge 161 a of the valve body 161 , is made large compared to the distance L 2 between the inner edge surface 137 b of the motor plunger hole 137 and the motor side surface 161 b of the valve body 161 . The larger distance is required because it is necessary to form a tilt fluid path 193 ( FIG. 10 ) joining the clutch valve hole 105 and the outer side passage 173 between the inner edge surface 113 b of the pump plunger hole 113 of pump cylinder 112 and pump side edge 161 a of the valve body 161 on the pump side; and therefore the pump plunger hole 113 are separated from the valve body 161 . There is no need to form a tilt fluid path on the (other) motor M side and therefore the distance between the inner edge surface 137 b of the motor plunger hole 137 and the motor side surface 161 b of the valve body 161 is small.
In the clutch mechanism of the hydrostatic continuously variable transmission of the preferred embodiment described above in detail, the pressure plate 184 and the slide shaft 186 are separately formed, the pressure plate 184 is efficiently manufactured through a press forming using a die and the slide shaft 186 is not accompanied by the plate, so that the cutting work with a machine can be efficiently performed. After both portions are manufactured, they are welded and integrally formed to enable themselves to become the roller bearing member 188 , so that production efficiency is improved. Furthermore, the aforesaid integral formation can also be carried out by brazing and the like in addition to welding.
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.
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A clutch mechanism for a hydrostatic continuously variable transmission has a hydraulic circuit including a high pressure oil path for feeding working oil from a hydraulic pump to a hydraulic motor and a low pressure oil path for feeding working oil from the hydraulic motor to the hydraulic pump. The clutch mechanism is located between the hydraulic pump and the hydraulic motor. A clutch valve is arranged on the transmission shaft and is slid by a centrifugal governor to cause the oil paths to be shortened. A cam plate member is arranged on the transmission shaft. A roller is engaged with the cam plate member and is moved outwardly in a diametrical direction by a centrifugal force. A roller bearing member receives a roller pressing force through outward motion of the roller. A pressure plate and shaft of the roller bearing member are separately formed and thereafter integrally formed.
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CROSS REFERENCE TO PENDING APPLICATION
[0001] This is a continuation of pending International application PCT/EP99/08436 filed on Nov. 4, 1999, which designates the United States and claims priority of German patent application DE 198 59 731 filed on Dec. 23, 1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an articulated arm for an awning, comprising a first arm part and at least a second arm part, wherein the first arm part and the second arm part are connected with each other via an articulation, the articulation axis of which runs transversely to the longitudinal axis of the arm parts, and wherein, in the first arm part, at least two springs adjacent to each other are arranged, with one end of the springs being fixed on the first arm part, and on the other end of the springs at least one flexible traction element is fixed which is led via the articulation into the second arm part, where it is fixed on the second arm part.
[0004] 2. Description of the Related Art
[0005] One type of articulated arm is generally known from European patent number EP 0 489 186 A1. The articulated arm mentioned is used in a certain type of awnings, in so-called articulated arm or folding-arm awnings. Such awnings have an awning fabric, which is held upon a fabric winding spindle in such a way that it can be wound up and wound off. A forward end of the awning fabric is fixed on an extension bar, which is moved away from the fabric winding spindle, if the awning fabric is wound off the fabric winding spindle, and which is moved towards the same when the awning fabric is wound up. The extension bar on which the forward end of the awning fabric is fixed is, at the same time, over the at least one, usually two articulated arms, connected to a supporting part of the awning, e.g. a support tube.
[0006] Such an articulated arm typically has at least two arm parts which are connected with each other via an articulation, the axis of which runs transversely to the longitudinal axis of the arm parts. One arm part, which is generally designated as the upper arm is, at the same time, connected in an articulated way with its end facing away from the articulation to the supporting part of the awning, i.e. the support tube. The other arm part, which is generally designated as the forearm is, with its end facing away from the articulation, connected to the extension bar in an articulated way.
[0007] When the awning is completely reeled in, wherein the awning fabric is completely wound up on the fabric winding spindle, the articulated arm is bent to its maximum, i.e. the first and the second arm part are nearly parallel and adjacent to each other and run approximately parallel with the extension bar and the support tube. When the awning is reeled out to its maximum extent, i.e. if the awning fabric is completely wound off the fabric winding spindle, the articulated arm is stretched.
[0008] The articulated arm or the articulated arms of the awning have the function to push away the extension bar, when the awning fabric is wound off the fabric winding spindle, in order to pull away the fabric under tension when it is wound off the fabric winding spindle. For that purpose, in one of the arm parts, e.g. in the upper arm of the articulated arm, at least one spring is arranged, the one end of which is fixed to the first arm part, and to the other end of which an end of at least one flexible traction element is fixed, e.g. in the shape of a wire cable or a chain, which is led over the articulation that connects the two arm parts into the second arm part, where it is fixed with its other end onto the second arm part.
[0009] When the awning is reeled in and the articulated arm is bent to its maximum, the spring, which is usually designed as a tension spring, is stretched to its maximum. When the articulated arm is bent, the distance length between the fixation point of the traction element on the forearm and the fixation point of the spring on the upper arm is, namely, enlarged by the curve length of the bent articulation. The spring is, thus, when the articulated arm is bent, stretched to its maximum, so that the bent articulated arm is prestretched in its stretched position, with the effect that the articulated arm, when the fabric is wound off, stretches on his own.
[0010] In order to pre-stretch the articulated arm even in an awning with a relatively high extension length correspondingly in its stretched position, high spring forces are often required. The springs used have, thus, a very high spring constant. In awnings with high extension length, moreover, at least two springs or even more springs are used, which are adjacently arranged in the one arm part.
[0011] In these articulated arms, the at least two springs are typically connected with each other, on their free end, by means of a brace, wherein one single suspension is arranged on the brace, e.g. in the shape of a hook, on which, then, one single traction element is commonly fastened. The traction element, thus, has to take up the force of two or more springs. The traction element is, correspondingly, much more stressed as if it was connected to only one spring. This may result in reduction of the endurance of the traction element, i.e. the durability under load of the traction element is reduced when the awning is reeled in and reeled out. The traction element is exposed to repeated alternating stress, in particular in the region of the articulation, where it experiences a deflection, so that the one traction element can tear earlier.
[0012] It has therefore been suggested to use, instead of one traction element, a string of several traction elements, which are tied together on their one end, which is connected to the end of the springs. In this way, however, again only one fixing point of all traction elements with all springs is created. In other words, again only a simple connection between the bunched end of the traction elements and the collected end of the springs exists, which, again, are exposed to higher stress. If this fixing point tears off during operating the awning, there is no connection anymore between the traction elements and the springs, and the function of the articulated arm is compromised. European patent EP 0 489 186 A1 discloses a similar articulated arm comprising two parallel chains as traction elements which are individually connected to the two springs, respectively.
[0013] Therefore, it is an object of the present invention to provide an improved articulated arm that can longer resist the repeated alternating stress when the awning is reeled in and out without suffering damage.
SUMMARY OF THE INVENTION
[0014] According to one aspect of the invention, this object is achieved by an articulated arm for an awning, comprising a first arm part and at least a second arm part each having a longitudinal axis, an articulation having an articulation axis, the first arm part and the second arm part being connected to each other via the articulation, and the articulation axis running transversely to the longitudinal axes of the arm parts, at least two springs arranged adjacent to each other and each of the springs having a first end and a second end, the first ends being fixed at the first arm part, at least two traction elements each having a first end and a second end, the first ends being individually connected to the second ends of the springs, and the traction elements being led via the articulation to the second arm part and fixed thereto, wherein at least one traction element is assigned to each spring and wherein the traction elements are wire cables, which comprise, at least in their region which is led via the articulation, a plastic coat.
[0015] In this aspect, instead of fixing one single traction element with its end together onto the at least two springs, or instead of bunching several traction elements on one end and then, bunched, connecting with all springs together, it is provided, according to the invention, to assign to each existing spring at least one separate traction element, which is, then, fixed only onto the spring that is assigned to it. Each traction element, therefore, has to take up the force of only one spring, which reduces the stress of each individual traction element. Further, instead of using chains as traction elements, the traction elements are wire cables having a plastic coat at least in the region of the articulation. The plastic coat advantageously reduces friction and wear of the wire cables in the region of the articulation. Durability under load tests have shown that the endurance of the articulated arm according to the invention in comparison with known articulated arms is by far higher even than the endurance of articulated arms using chains.
[0016] Another advantage of this embodiment of the articulated arm of the invention is that, should one traction element tear, the at least one further traction element and the at least one further spring are still connected, so that the function of the articulated arm is at least partly maintained, and that then the connection still existing of the remaining traction element with the remaining spring is exposed to no higher stress than if all traction element spring connections were intact. This object of the invention is in that way completely achieved.
[0017] In another aspect, the traction element assigned to the corresponding spring is fixed, with its second end, individually on the second arm part. By this measure, the operational safety of the articulated arm is increased even further, as in this embodiment both ends of the traction element are fixed individually both to the assigned spring and to the fixation point on the second arm. Alternatively, however, if the traction elements are bundled, on their end fixed on the second arm part to one end, and the bundled end is fixed on the second arm part, the collection or bundling of the ends fixed onto the second arm part, which are still fixed individually on each spring, has the advantage that the traction elements can more easily be fixed when the articulated arm is mounted, since, then, only one end has to be fixed onto the second arm part.
[0018] In a further aspect, the springs are coil springs and an insert nut is fixed on at least one end of these springs, respectively, into which a suspension eyelet is screwed. This configuration of the springs also contributes to higher endurances of the articulated arm. In usual articulated arms, namely, coil springs are generally used, the ends of which are formed into a hook. Forming of a coil spring end into a hook leads, however, to material weakening and earlier material fatigue of the springs in the region of the hook-shaped formed ends.
[0019] By fixing an insert nut onto at least one end of the springs, as it is provided according to this aspect of the invention, into which a suspension eyelet is screwed, a fixation point for the traction element or for the fixation of the spring on the first arm part is created, which eliminates the need for the spring being formed and, thus, from experiencing material fatigue. It is then preferred if the insert nuts are rolled or pressed into the spring. By this measure, a particularly tight connection that can resist high stress is created between the insert nut and the spring.
[0020] In yet another aspect, at least two traction elements are assigned to each spring. In this embodiment, the at least two traction elements are preferably, according to the invention, individually fixed onto the spring assigned to them. By assigning at least two traction elements per spring, the endurance of the articulated arm can be increased even further.
[0021] Further advantages can be taken from the description and the enclosed drawings. It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] An embodiment of the invention is shown in the drawings and will be explained in more detail in the description below. In the drawings:
[0023] [0023]FIG. 1 shows a schematic perspective presentation in total of an awning; and
[0024] [0024]FIGS. 2A and 2B shows an articulated arm according to the invention in two partial pictures, partly in longitudinal section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Reference will now be made to the drawings wherein like numerals refer to like parts throughout. In FIG. 1, one embodiment of an awning designated with the general reference number 10 is shown, partly in a discontinuous way. Awning 10 is used for shading terraces and the like. Awning 10 has a support tube 12 , which is used as supporting part of awning 10 , and via which awning 10 is fixed by means of wall consoles 14 onto a building wall (not shown). Wall consoles 14 are, on one side, fixed onto the support tube 12 and have fixation portions for fixing on the building wall, which are not shown in detail but is performed in a manner well understood by one of ordinary skill in the art.
[0026] Awning 10 has further an awning fabric 16 (shown in ghost view if FIG. 1), which can be wound up and wound off of fabric winding spindle 18 , which is represented with broken lines. For that purpose, fabric winding spindle 18 is in connection with a gear, which is not shown in detail, on one end of fabric winding spindle 18 , which can be manually driven by a crank handle, or is alternatively driven via an electric motor. Fabric winding spindle 18 can be driven via the gear in two senses of rotation around its longitudinal axis.
[0027] Fabric winding spindle 18 is, except a front slot 19 running parallel to fabric winding spindle 18 , surrounded about its circumference by a sleeve 20 , which protects the fabric 16 being wound onto fabric winding spindle 18 from detrimental environmental influences. Sleeve 20 is retained, on both ends, by means of side parts 22 fixed onto support tube 12 .
[0028] Awning 10 further has an articulated arm 24 and another articulated arm 26 , articulated arm 26 and articulated arm 24 being designed, in this embodiment, identically to each other and being arranged substantially mirror-symmetrically to each other, so that in the following only articulated arm 24 will be further described. It should be understood that the description of a single articulated arm 24 that follows refers equally to multiple articulated arms 24 , 26 .
[0029] Articulated arm 24 has a first arm part 28 , which is also designated as upper arm. Articulated arm 24 further has a second arm part 30 , which is also designated as forearm. First arm part 28 and second arm part 30 are articulatedly connected with each other via an articulation 32 , whereby a rotational axis of articulation 32 runs transversely to the longitudinal direction of first arm part 28 and/or to the longitudinal direction of second arm part 30 .
[0030] First arm part 28 is connected, with its end 34 facing away from articulation 32 , over a supporting trestle 36 , with support tube 12 . First arm part 28 is, therewith, articulatedly connected to supporting trestle 36 . Second arm part 30 is connected, articulatedly, with its end 38 facing away from articulation 32 with an extension bar 40 .
[0031] One function of articulated arm 24 and also of articulated arm 26 is to locate extension bar 40 , and, when awning fabric 16 is wound off, to push extension bar 40 away from fabric winding spindle 18 . When awning fabric 16 is completely wound up on fabric winding spindle 18 , extension bar 40 rests closely adjacent slot 19 of sleeve 20 . Articulated arm 24 and articulated arm 26 are then bent to their maximum extents, i.e. first arm part 28 and second arm part 30 extend approximately parallel to support tube 12 , i.e. first arm part 28 and second arm part 30 are folded together around articulation 32 . The same applies for articulated arm 26 .
[0032] Proceeding from this state reeled-in to its maximum, awning fabric 16 can be wound off by turning fabric winding spindle 18 , whereby articulated arms 24 and 26 have the function to push extension bar 40 away from fabric winding spindle 18 and to pull away awning fabric 16 wound off under stress from fabric winding spindle 18 , so as to inhibit sag of the awning fabric 16 . To fulfill this function, articulated arm 24 is prestressed from the maximally bent into the stretched position by adding spring force. This is described in the following with reference to FIG. 2A and 2B.
[0033] [0033]FIGS. 2A and 2B show articulated arm 24 in total in two section, broken views. The right end in FIG. 2B adjoins, correspondingly, to the left end in FIG. 2A. According to FIG. 2A, first arm part 28 is formed by a tubular member 42 .
[0034] At a first end 34 of first arm part 28 , a fork 44 is mounted onto tubular member 42 , which is connected with supporting trestle 36 in an articulated way according to FIG. 1. Fork 44 has, through it, a continuous bore 46 , through which a pivot pin (not shown) can be put, which produces the articulated connection with supporting trestle 36 in a well understood manner.
[0035] Fork 44 also has a block-like extension 48 , which encloses end 34 of first arm part 28 and projects partly into tubular member 42 . Onto extension 48 , in this embodiment, three suspensions 50 a - c in the shape of crooked hooks are fixed.
[0036] In tubular member 42 , in this embodiment, three springs 52 a - c are arranged adjacent to each other. Springs 52 a - c, in this embodiment, are designed in the shape of coil springs and act as tension springs, i.e. in a force-free state, springs 52 a - c are pulled together to their maximum and can be stretched by tension in their longitudinal direction. Onto respective first ends 54 a - c of springs 52 a - c, an insert nut 56 a - c is fixed, respectively. Insert nuts 56 a - c are rolled or pressed onto the respective end 54 a - c and extend to e.g. some windings into the ends 54 a - d of springs 52 a - c. In addition, the insert nuts 56 a - c in springs 52 a - c can be welded with the same. In insert nuts 56 a - c, a respective suspension eyelet 58 a - c, which are designed in this embodiment as closed ring eyelets, is affixed to. In suspension eyelets 58 a - c, the respective hook of suspensions 50 a - c is hooked into.
[0037] Each of springs 52 a - c is, thus, individually fixed onto first arm part 28 , more exactly, onto extension 48 . Each of springs 52 a - c is associated with a traction element 60 a - c. In that way, each traction element 60 a - c is, individually, firmly connected to a respective second end 62 a - c of its associated spring 52 a - c.
[0038] In order to fix traction elements 60 a - c insert nuts 64 a - c are firmly connected with second ends 62 a - c respectively. In insert nuts 64 a - c suspension eyelets 66 a - c are screwed into, which are designed in the shape of ring eyelets. A respective first end 68 a - c is respectively laid to a loop 70 a - c, which grips through the respectively assigned suspension eyelet 66 a - c and is thus firmly connected to the latter. Loops 70 a - c are, by means of a squeezing device or a squeezing ring, fixed in an undetachable way. First ends 68 a - c are still, in first arm part 28 , positioned within tubular member 42 .
[0039] According to FIG. 2B, on first arm part 28 adjacent end 72 of the first arm part 28 , again, a fork 74 is firmly connected with tubular member 42 . Fork 74 forms a first part of articulation 32 , via which first arm part 28 is articulatedly connected with second arm part 30 . Second arm part 30 is also formed by a tubular member 76 , at a first end 35 of which facing articulation 32 , a block 78 is firmly connected with the tubular member 76 , wherein block 78 engages with an extension 80 into fork 74 . A pivot pin 82 indicated with broken lines passes through fork 74 and extension 80 of block 78 .
[0040] Traction elements 60 a - c are led over articulation 32 , more exactly, over fork 74 , extension 80 of block 78 and block 78 itself into tubular member 76 of second arm part 30 . On extension 80 or block 78 , traction elements 60 a - c rest. A respective second end 82 a - c of traction elements 60 a - c is respectively individually connected with second arm part 30 , for the sake of which a slot 84 a - c is provided in block 78 for each end 82 a - c, respectively, in which the respective end 82 a - c is secured into and, via tubular member 76 , is connected with block 78 in such a way that it resists extension. Ends 82 a - c are in this connection, again, laid into loops, which, by means of a squeezing device or a ring, are secured against detaching.
[0041] In an alternative embodiment, instead of fixing ends 82 a - c individually in block 78 , for the sake of which three slots 84 a - c are provided, it can also be provided to collect ends 82 a - c to one single end, e.g. by bunching or bundling by means of a squeezing device or a squeezing ring, and then attach this collected end onto block 78 , for the sake of which only one of the slots 84 a - c needs to be there.
[0042] On end 38 of second arm part 30 , a fixation element 86 is arranged, over which second arm part 30 is connected, articulatedly, with extension bar 40 according to FIG. 1. Traction elements 60 a - c are flexible, so that they can adjust, in the region of articulation 32 , when articulated arm 24 is bent, to the curved transition from first arm part 28 to second arm part 30 , and are substantially unextensible, so that they can transmit tensile forces. When articulated arm 24 is bent, springs 52 a - c, due to the increasing distance length, which overstrain traction elements 60 a - c in the region of articulation 32 , are strained and, thus stressed.
[0043] It can be seen from FIGS. 2A and 2B that each traction element 60 a - c with its corresponding spring 52 a - c forms an individual force transmitting system which is independent of other traction elements 60 a - c and other springs 52 a - c. If there is, for example, a rupture of traction element 60 a, force transmitting systems from traction elements 60 b, 60 c and respective springs 52 b, 52 c remain intact, so that articulated arm 24 remains operative, although with reduced tension force.
[0044] Traction elements 60 a - c in this embodiment are designed as wire cables, which have, at least in the region of articulation 32 , in which traction elements 60 a - c rest upon extension 80 of block 78 , a plastic coat. Friction of traction elements 60 a - c on extension 80 is thereby reduced.
[0045] In the embodiment shown, each spring 52 a - c is assigned with a traction element 60 a - c. It can also be provided to assign to each spring 52 a - c two or more traction elements 60 a - c, whereby each force transmitting system formed in that way is designed independently from the other force transmitting systems.
[0046] While the embodiment shown has three springs 52 a - c, it is also possible, in the scope of the invention, to provide an articulated arm with two springs or four or more springs. In the scope of the invention, it is also possible to connect ends 62 a - c of springs 52 a - c with each other, whereby a brace used for it has suspensions in corresponding number, in order to be able to suspend these individually. It will also be appreciated that additional articulated arms 24 , 26 can be included for an awning 10 of greater width.
[0047] Although the foregoing description of the preferred embodiment of the present invention has shown, described, and pointed out the fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes in the form of the detail of the apparatus as illustrated as well as the uses thereof, may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the present invention should not be limited to the foregoing discussions, but should be defined by the appended claims.
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An articulated arm for an awning such as for a patio or deck including at least first and second arm parts joined by an articulation. Longitudinal axes of the arm parts are orthogonal to the articulation axis. The articulated arm also includes at least two springs arranged adjacent each other and first ends of the springs are fixed to the first arm part. At least two traction elements are also and are individually connected to second ends of the springs. The traction elements are led via the articulation to the second arm part and are fixed thereto. The traction elements are wire cables which include a plastic coat in at least a region adjacent the articulation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to clothes dryers and more particularly to a cabinet construction for a clothes dryer.
2. Description of the Prior Art
In clothes dryers having a horizontal rotating drum there is generally provided an outer cabinet which encloses a drum, an electric motor used to rotate the drum as well as drive an air blower, and a heater which conditions the air used in the drying operation. The cabinet is generally formed out of sheet metal, separately formed into various panels or groups of panels such as the top panel, front panel, rear panel, bottom panels and side panels. Generally, the rear panel is made removable for access to the mechanisms such as the motor and heater described above. Such a removable rear panel is shown in U.S. Pat. No. 2,830,384 at 27. Since the rear panel is generally hidden from view, exposed screws are utilized to hold the panel to the dryer frame as illustrated in FIG. 6. A similar removable back panel 206 is illustrated in U.S. Pat. No. 2,798,306 in FIG. 3. By making only the rear panel removable requires that the back of the dryer be accessible if service to an of the interior mechanisms is required. This often requires the dryer, which is heavy and bulky, to be pulled out of an installed location and sometimes requires the serviceman to work in a somewhat cramped space. Thus, it would be advantageous to provide a clothes dryer having a removable front panel.
U.S. Pat. No. 4,324,035, assigned to the assignee of the present application, discloses a method of attaching a removable cabinet for front-serviceable appliances in which the appliance has a base frame supporting internal components, the base frame having a front member and side members and a rear panel attached thereto. A removable cabinet has a front bottom flange overlapping and extending beneath the front base frame member. Receptacles for receiving upwardly extending tabs from the side members are provided to position the cabinet with respect to the base. The cabinet is held in position on the base by a pair of spring clips engaging the rear panel and each having a portion abutting a top of the cabinet and curved portions extending into the cabinet through aligned slots in the top thereof to maintain a spring tension. The cabinet is thus retained without the use of screws and its removal does not impair the functional operation of the internal components.
SUMMARY OF THE INVENTION
The present invention provides for a construction for a dryer cabinet in which the top and front panels can be removed from the front of the dryer without requiring the back of the dryer to be accessed. A pair of brackets are utilized to secure both the top panel and the front panel to the side panels of the cabinet. The front panel is retained on the brackets by a pair of screws which are normally hidden from view by the overlapping top panel. The top panel is slidingly held in place by a tab on the bracket as well as by screws engaging the rear of the top panel below a pivotable console.
Thus, removal of the front and top panels of the dryer is easily and quickly accomplished by the removal of only four or five screws thus providing access to the interior of the cabinet for servicing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a dryer embodying the principles of the present invention.
FIG. 2 is a partial side sectional view of the top portion of the dryer cabinet.
FIG. 3 is an exploded view of the dryer cabinet.
FIG. 4 is a front view of the cabinet corner bracket.
FIG. 5 is a top view of the cabinet corner bracket.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is illustrated a horizontal access clothes dryer 10 embodying the principles of the present invention. The dryer is comprised of a cabinet 12 having a front panel 14 with an openable door 16 revealing an access opening 18. A console 20 having presettable controls 22 thereon allows an operator to select a program of automatic drying and tumbling in a laundry drying process. The door 16 in the front panel 14 of the cabinet 12 permits access through the access opening 18 into the interior of a drum 24 having open ends which is rotatably mounted within the cabinet 12. Below the drum but within the cabinet 12 on one side there is provided an electric motor 26 which rotatably drives the drum by means of a belt 28 and also drives a blower 29. A stationary back panel 30 is provided which has inlet openings (not shown) within the drum for the passage of air circulated by the blower 29 which is used in the drying process. The blower 29 draws air from the drum 24 through a lint filter 34 positioned below the door 16. A heater 35 conditions the air before it enter the drum through the inlet openings. The stationary back wall also has mounted thereon two rollers 36 which support the rear portion of the drum 24. A front portion of the drum is supported by a pair of additional rollers (not shown). A stationary drum front bulkhead 37 is provided between the dryer front panel 14 and the rotating drum 24.
The parts that make up the dryer cabinet 12 are shown in an exploded view in FIG. 3 where it is seen that the dryer cabinet has a pair of opposed, fixed side panels 38, 40 and a fixed bottom panel 42. The side panels 38, 40 and bottom panel 42 may be formed of a single sheet of sheet metal appropriately bent into the configuration shown. Each of the side panels and bottom panels has an inwardly turned flanged edge 46, 48, 50 respectively extending around the periphery of each of those panels. The back panel 30 is secured by appropriate fasteners or by welding to the rear edge flange 46R, 48R of the side and bottom panels.
The back panel 30 has an inwardly turned top flange 54 which overlies and is spot welded at 55 (FIG. 2) to the top edge flanges 46T, 48T of the side panels. An upper rear panel 56 is secured by screws 57 (FIG. 2) to project upwardly above the top edge flange 54 of the rear panel 30. The upper rear panel 56 has a plurality of forwardly extending tabs 58 which are spaced above the top flange 54 of the rear panel.
A top panel 60 is provided which overlies the top edge flanges 46T, 48T of the side panels and the top flange 54 of the rear panel and a top flange 62 of the front panel 14, but which underlies the tabs 58 of the upper rear panel 56. The top panel 60 has along a rear edge 64, fastener openings 66 which align with openings 68 in the tabs 58 of the upper rear panel 56 and recesses 69 for control wires to pass from the console 20 to the mechanisms interior of the dryer cabinet without passing through the top panel. The top panel 60 has a downwardly turned flange 70 extending around the side and front periphery of the top panel 60, which side flange 70 continues into a return flange 72 which proceeds parallel with the top exposed surface of the top panel 60. The return flange 72 has an enlarged portion 74 at each forward side corner (FIGS. 3 & 5; only one shown) which extends rearwardly a short distance, whose purpose is explained in greater detail below.
The front panel 14 has a pair of downward extensions 76 positioned at either lateral side of the panel along a bottom edge 78 thereof. The extensions each have a downwardly opening slot 80 which is positioned to engage a post member, such as screw 82, projecting from the front flanges 46F, 48F of the side panels 38, 40. The post and slot engagement provides a positive vertical positioning and alignment of the front panel relative to the side panels. A removable toe panel 84 is positioned below the front panel 14 and removably attaches to the side panels 38 and 40.
A pair of brackets 86, 88 are attached to the edge flanges 46, 48 of the side panels at the corner of the top edge and front edge to provide a means for attaching the front panel 14 and top panel 60 to the side and bottom panels. As seen in FIGS. 2, 4 and 5, the brackets 86, 88 have a top plate portion 90 which overlies and is secured to the top edge flange 48T of the side wall such as by welding. A lip portion 92 extends forwardly beyond the front edge flange 48F and is connected to a downwardly extending support arm 94 which angles rearwardly toward the front flange 48F and terminates in a mounting end 96 which can be secured to the front edge flange of the side panels again by welding. The forwardly extending lip 92 has a aperture 98 therein for receiving a threaded fastener or screw 100. The top plate portion 90 has a forwardly extending tab 102 spaced slightly above the plate 90 to capture the enlarged portion 74 of the return flange 72 of the top panel 60.
The assembly of parts is shown in detail in FIG. 2 which illustrates the bracket 88 secured to the top 48T and front 48F flanges of the side panel 40. The top flange 62 of the front panel 14 overlies the projecting lip 92 of the bracket 88 and has an aperture 104 therein to receive the screw 100 to secure the front panel 14 to the bracket 88 and thus to the side panel 40. An identical arrangement is provided at the side panel 38 and bracket 86.
The top panel 60 is placed on the top edge flanges 46T, 48T of the side panels and the top flange 62 of the front panel such that a front edge 106 of the top panel is extended forwardly of the front panel 14. The top panel 60 is then slid rearwardly until the rear edge 64 slides under the forwardly projecting flanges 58 of the top rear panel 56 and the enlarged portion 74 of the return flange 72 slides beneath the tab 102 of the bracket 88. In this manner, both the rear edge 64 and front edge 106 of the top panel 60 are secured against vertical movement. The flanges 72 acting against tabs 102 prevent horizontal movement of the top panel front portion. Two or three threaded fasteners such as screws 108 can then be secured through the flanges 58 and apertures 66 along the rear edge 64 of the top panel to prevent the top panel from sliding forwardly. In this position the front edge 106 of the top panel will overlie the top flange 62 of the front panel such that the screws 100 will not be exposed and can be removed only by prior removal of the top panel.
The console 20 is pivotally attached to the top rear panel 56 and can be pivoted downwardly to overlie the rear edge 64 of the top panel 60 and thus cover the screws 108.
The top and front panels are quickly and easily removed by first pivoting the console upwardly as illustrated in phantom in FIG. 2 to provide access to the fasteners 108 securing the tabs 58 and top panel 60 together. Once the fasteners are removed, the top panel 60 is slid forwardly to disengage the return flange 72 from the tab 102 at which time the top panel can be completely removed from the remainder of the dryer cabinet. With the top panel removed, the two retaining screws 100 holding the front panel 14 to the side panels 38, 40 are exposed. By removing the two screws 100 and loosening the screws 82, the front panel can then be removed upwardly away from the remainder of the dryer assembly disengaging the slots 80 from the screws 82. Thus, the dryer may be serviced, that is the part replaced or the other internal mechanisms removed or serviced without accessing the rear of the dryer. Also, by removing the toe panel 84 and the top panel 60 in accordance with the above procedure, the console can then be pivoted back into place to operate the dryer with the top and toe panels removed if desired to visually check the operation of the dryer internal parts. Thus, such a construction greatly enhances the ease of serviceability of the dryer while maintaining an easy to assemble cabinet structure.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
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A cabinet construction for a clothes dryer is provided wherein the top panel and the front panel are removable from the cabinet assembly from the front of the appliance for purposes of servicing the mechanisms interior of the cabinet all from the front of the dryer. A pair of brackets are attached at the top front corner of the side panels to which both the front panel and top panel are secured. The front panel screws into a projecting lip on said brackets, and the top panel slides rearwardly on the top edges of the side panels until a return flange on the top panel engages with a tab on the brackets to hold the top panel vertically. The top panel is then removably secured in place with at least one screw along the rear edge thereof which is covered by a pivotable control console.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel delivery pipe with damper function adapted for use in an engine of the electronically controlled fuel injection type and a manufacturing method of the same.
2. Discussion of the Prior Art
Disclosed in Japanese Patent Publication No. 4230100 is a conventional fuel delivery pipe of this kind which is constructed of lower and upper cases integrally jointed by brazing, the lower case being provided at its bottom with a plurality of injection sockets spaced in a longitudinal direction for connection with fuel injection valves, and the upper case being in the form of a double walled structure the interior of which is subdivided into air chambers by means of a box-shaped wall panel in an air-tight manner. In the fuel delivery pipe, the air trapped in the air chambers is expanded and contracted by heating and cooling of the brazed wall panel, resulting in deformation of the wall panel. This causes difference in damper function of pressure pulsations of each fuel delivery pipe. To solve the problem, an air hole is provided in the upper case for communication with the atmosphere and is closed by a cap member after brazing process of the lower and upper cases. In a fuel delivery pipe disclosed in Japanese Patent No. 3217775, a damper member in the form of a metallic pipe of flat-circular in cross-section sealed at its opposite ends to contain therein gas is assembled within a case body of the fuel delivery pipe. The damper member is brazed at its opposite ends to the case body and is sealed at its one end after brazed by means of a seal plug attached from the exterior of the case body.
As in the fuel delivery pipes described above, the cap member or the seal plug is needed to close the air chamber in communication with the atmosphere, the number of component parts increases, resulting in difficulty of reduction of the manufacturing cost. As the head of the cap member projects from the fuel delivery pipe, a space for mounting the delivery pipe increases. In addition, the capacity for absorbing fluctuation of fuel pressure is restricted by the wall panel provided in the upper case.
SUMMARY OF THE INVENTION
To solve the foregoing problems, an object of the present invention is directed to provide a fuel delivery pipe with damper function, comprising: an elongate lower case provided at its bottom with a plurality of injection sockets for connection with fuel injection valves to be opened and closed under control of a controller unit; an upper case coupled with the lower case in a liquid-tight manner to form an internal space to be filled with fuel under pressure supplied from a fuel pump; a hollow partition wall member the whole periphery of which is fixed to an inner surface of the lower or upper case to form an air chamber isolated from the internal space; and a vent hole formed in the lower or upper case and sealed after communicating the air chamber with the atmosphere therethrough; wherein the partition wall member is flexible in accordance with pressure pulsations of fuel in the internal space caused by open-and-close operation of the injection valves to fluctuate the capacity of the air chamber in the internal space thereby to damp the pressure pulsations and to reduce disorder of the injection amount of fuel, and wherein the vent hole is in the form of a cylindrical hole formed by cutting or punching to be smaller in diameter than the thickness of the lower or upper case and sealed by the mother metal of the lower or upper case or a filler metal melted by local heating at its outer periphery and hardened by cooling.
In a practical embodiment of the present invention, it is preferable that the vent hole is in the form of a burring hole formed by pushing a punch pointed at its tip into the bottom wall of the lower case or the peripheral wall of the upper case. It is also preferable that the hollow partition wall member is constructed of an elongate top wall, a peripheral wall downward from the whole periphery of the top wall and a lateral flange extended outward from the lower end of the peripheral wall, wherein the lateral flange of partition wall member is fixed to a flat portion of the lower or upper case in a liquid-tight manner to form the air chamber.
In another practical embodiment of the present invention, it is preferable that the height of the peripheral wall of the partition wall member is formed larger than the width of the top wall so that opposed portions of the peripheral wall are flexible to fluctuate the capacity of the air chamber thereby to absorb pressure pulsations of fuel in the internal space for reducing disorder of the injection amount of fuel. It is also preferable that at least one of injection sockets is arranged at a one-sided position in a width direction across the longitudinal direction of the bottom wall, wherein the partition wall member is placed at an opposite-sided position in the width direction to occupy a greater part of the bottom wall of the lower case.
In a practical embodiment of the present invention, it is preferable that the injection sockets each are comprised of a separately formed cylindrical body for connection with the respective injection valves and a cylindrical projection smaller in diameter than the cylindrical body, wherein the cylindrical projection is positioned in engagement with a mounting hole of the lower case such that the interior of the cylindrical body is in open communication with the internal space. Furthermore, it is preferable that the hollow partition wall member is divided into a plurality of hollow partition wall members which are arranged among the injection sockets and brazed on the bottom wall of the lower case, wherein the bottom wall of the lower case is formed with a plurality of vent holes which are sealed after communicating each interior of the partition wall members with the atmosphere.
In a practical embodiment of the present invention, there is provided a fuel delivery pipe with damper function, comprising an elongate lower case provided at its bottom with a plurality of sockets for connection with fuel injection valves to be opened and closed under control of a controller unit; an upper case coupled with the lower case in a liquid-tight manner to form an internal space to be filled with fuel under pressure supplied from a fuel pump; a cylindrical partition wall member having at least one end fixed to an inner surface of the lower case or upper case to form an air chamber isolated from the internal space; and a vent hole formed in the lower case or upper case at a position for connection with the one end of the partition member to be sealed after communicating the air chamber with the atmosphere; wherein the partition wall member is flexible in accordance with pressure pulsations of fuel in the internal space caused by open-and-close operation of the injection valves to fluctuate the capacity of the air chamber in the internal space thereby to damp the pressure pulsations of fuel and to reduce disorder of the injection amount of fuel, and wherein the vent hole is in the form of a cylindrical hole formed by cutting or punching to be smaller in diameter than the thickness of the lower or upper case and sealed by the mother metal of the lower or upper case or a filler metal melted by local heating at its outer periphery and hardened by cooling. In this embodiment, it is preferable that the vent hole is in the form of a burring hole formed by pushing a punch pointed at its tip into the lower or upper case.
In the fuel delivery pipe described above, it is preferable that the upper case is formed with an inwardly bent portion along a longitudinal direction which is displaced in its thickness direction to fluctuate the capacity of the internal space in accordance with pressure pulsations of fuel caused by open-and-close operation of the injection valves thereby to absorb the pressure pulsations of fuel and to reduce disorder of the injection amount of fuel.
In a manufacturing process of the fuel delivery pipe, it is preferable that the vent hole is sealed by the mother metal of the lower or upper case or a filler metal melted by local heating at its outer periphery and hardened by cooling after brazing and cooling of the lower and upper cases.
In the foregoing fuel delivery pipes of the present invention, the hollow partition wall member positioned to form the air chamber in the internal space between the lower and upper cases is flexible in accordance with pressure pulsations of fuel caused by open-and-close operation of the fuel injection valves to fluctuate the capacity of the air chamber thereby to absorb the pressure pulsations of fuel and to reduce disorder of the injection amount of fuel. This is effective to improve the fuel-air ratio and to eliminate vibration of the fuel deliver pipe and unwanted noises. In the case that the cylindrical vent hole is formed by cutting or punching to be smaller in diameter than the thickness of the lower or upper case and that the mother metal of lower or upper case around the vent hole is locally melted by heating means and hardened by cooling to seal the vent hole after the component parts of the fuel delivery pipe were brazed, the vent hole can be sealed without any cap member used in a convention conventional fuel delivery pipe. This is useful to reduce the number of component parts and the manufacturing cost of the fuel delivery pipe.
In the case that a punch pointed at its tip is pushed into the bottom wall of the lower case or the peripheral wall of the upper case to form the vent hole in a burring hole shape, the vent hole can be formed without cutting chips and sealed by local heating of the mother metal of the lower or upper case even if the vent hole is formed larger in diameter than the thickness of the bottom wall or peripheral wall.
In the case that the hollow partition wall member is constructed of an elongate top wall, a peripheral wall downward from the whole periphery of the top wall and a lateral flange extended outward from the lower end of the peripheral wall, wherein the lateral flange of the partition wall member is fixed to a flat portion of the lower or upper case in a liquid-tight manner to form the air chamber, the hollow partition wall member forming the air chamber can be made of drawing of a sheet metal of thin thickness at a low cost.
In the case that the height of the peripheral wall of the partition wall member is formed larger than the width of the elongate top wall, opposed portions of the peripheral wall are flexible to fluctuate the capacity of the air chamber to absorb pressure pulsations of fuel in the internal space caused by open-and-close operation of the injection valves thereby to eliminate disorder of the injection amount of fuel.
In the case that at least one of the injection sockets is arranged at one-sided position in a width direction across the longitudinal direction of the bottom wall of the lower case and that the partition wall member is placed at an opposite-sided position in the width direction to occupy a greater part of the bottom wall of the lower case, the number of component parts can be reduced for decreasing the manufacturing cost, and the capacity of the air chamber can be enlarged to eliminate disorder of the injection amount of fuel.
In the case that the injection sockets each are comprised of a separately formed cylindrical body for connection with the respective injection valves and a cylindrical projection smaller in diameter than the cylindrical body and that the cylindrical projection is positioned in engagement with a mounting hole of the lower case such that the interior of the cylindrical body is in open communication with the internal space, the cylindrical projection of the injection socket can be fixed in place without any interference with the partition wall member to enlarge the air chamber for reducing disorder of the injection amount of fuel.
In the case that the hollow partition wall member is divided into a plurality of hollow partition wall members which are arranged among the injection sockets and brazed on the bottom wall of the lower case and that the bottom wall of the lower case is formed with a plurality of vent holes which are sealed after communicating each interior of the divided partition wall members with the atmosphere, the lower and upper cases can be formed approximately straight to facilitate the manufacture of the fuel delivery pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a sectional plan view of a fuel delivery pipe with damper function in a first embodiment of the present invention;
FIG. 2 is a sectional view of the fuel delivery pipe taken along line 2 - 2 in FIG. 1 ;
FIG. 3 is a cross-sectional view taken along line 3 - 3 in FIG. 2 ;
FIG. 4 is a cross-sectional view taken along line 4 - 4 in FIG. 2 ;
FIG. 5 is a sectional plan view of a fuel delivery pipe with damper function in a second embodiment of the present invention;
FIG. 6 is a sectional view of the fuel delivery pipe taken along line 6 - 6 in FIG. 5 ;
FIG. 7 is a cross-sectional view taken along line 7 - 7 in FIG. 6 ;
FIG. 8 is a cross-sectional view taken along line 8 - 8 in FIG. 6 ;
FIG. 9 is a sectional view of a fuel delivery pipe with damper function in a third embodiment of the present invention;
FIG. 10 is a cross-sectional view taken along line 10 - 10 in FIG. 9 ;
FIG. 11 is a cross-sectional view taken along line 11 - 11 in FIG. 9 ; and
FIG. 12 is illustration of a forming method of a vent hole in a modification of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
First of all, a first embodiment of a fuel delivery pipe with damper function in accordance with the present invention will be described with reference to FIGS. 1˜4 . The fuel delivery pipe 10 comprises an elongate lower case 11 , three injection sockets 12 and two brackets 13 brazed to the bottom wall 11 a of lower case 11 , a hollow partition member 14 brazed to an inner surface of the bottom wall 11 a in a liquid-tight manner, an elongate upper case 15 brazed to the lower case 11 to enclose the lower case in a liquid-tight manner, and a fuel supply pipe 16 brazed at its one end to the right end of upper case 15 . The component parts 11 ˜ 16 are made of steel and plated with nickel for anti-corrosion. The main body of fuel delivery pipe 10 composed of the lower and upper cases 11 and 15 brazed to each other in a liquid-tight manner is in a longitudinal configuration complicated in a plan view, and the whole length of the main body is 236.6 mm.
As shown in FIGS. 1˜4 , the elongate lower case 11 is in the form of a stamped sheet-metal formed with a flat bottom wall 11 a and an upright flange 11 b raised from the whole periphery of bottom wall 11 a . As shown in FIG. 1 , the plane configuration of lower case 11 is comprised of a laterally elongate main part forming the greater part of lower case 11 , an upward portion projected from the central part of lower case 11 and upwardly crooked end portions extending from opposite ends of lower case 11 . As shown in FIG. 1 , the bottom wall 11 a is formed at its upward projected portion and crooked end portions with equally spaced mounting holes 11 c for positioning injection sockets 12 in place. The upward projected portion of lower case 11 is formed with an arcuate projection 11 e concentric with the central mounting hole 11 c for engagement with the injection socket 12 . The bottom wall 11 a is at its center with a cylindrical vent hole 11 d smaller in diameter (for instance, 0.5 mm) than half the thickness of bottom wall 11 a (for instance, 1.0 mm or 1.2 mm). (See two-dots chain line in a partly enlarged view of FIG. 3 )
As shown in FIGS. 1˜4 , the injection sockets 12 each are in the form of a bottomed cylindrical body 12 a integrally formed with a cylindrical portion 12 b projected outward from the bottom of body 12 a . The injection sockets 12 each are positioned in engagement with the mounting hole 11 c at their cylindrical projection and brazed to the bottom surface of lower case 11 in a fluid-tight manner. The interior of each injection socket 12 is in open communication with an internal space A between the lower case 11 and upper case 15 through an opening 12 c of the cylindrical projection 12 b . Brackets 13 each formed with a mounting hole 13 a are positioned in engagement with the bottom surface of lower case 22 and brazed in place.
As shown in FIGS. 1˜4 , the hollow partition wall member 14 is in the form of a stamped sheet metal comprised of an elongate top wall 14 a rounded at its opposite ends, a peripheral wall 14 b downward from the whole periphery of top wall 14 a , and a radial flange 14 c extended outward from the lower end of peripheral wall 14 b . The thickness of partition wall member 14 is, for instance, 0.35 mm. The whole length and width of partition wall member 14 occupies a greater part of the elongate lower case 11 . The partition wall member 14 is positioned in engagement with a flat portion of lower case 11 at its radial flange 14 c and brazed in place in a liquid-tight manner to form an air chamber B with the lower case 11 . The air chamber B is communicated with the atmosphere through the vent hole 11 d.
As shown in FIGS. 1˜4 , the elongate upper case 15 is in the form of a stamped sheet metal formed with a peripheral wall 15 a coupled with the whole periphery of upright flange 11 b of lower case 11 and a ceiling wall 15 b enclosing the upper side of peripheral wall 15 a . The peripheral wall 15 a is formed with a plurality of circumferentially spaced inward projections 15 e to be engaged with the upper edge of upright flange 11 b . When coupled with the upright flange 11 b of lower case 11 , the peripheral wall 15 a of upper case 15 is positioned by engagement with the upper edge of upright flange 11 b at its inward projections 15 e and brazed in place to the upright flange 11 b to form an internal space A to be filled with fuel. The air chamber B is positioned in the internal space A but isolated from the internal space A by means of the partition wall member 14 . In this embodiment, the cross-section of upper case 15 is arcuated at its whole corner and formed in a two-step trapezoid as shown in FIG. 3 . In FIGS. 1 and 2 , the right end portion of upper case 15 in the longitudinal direction is formed rectangular in cross-section as shown in FIG. 4 to enlarge the internal space thereof. The upper case 15 is formed at its right end with a flanged opening 15 d by burring. One end of the fuel supply pipe 16 is inserted into the flanged opening 15 d and brazed to the right end of upper case 15 .
In the process of the fuel delivery pipe 10 , the sockets 12 , brackets 13 and partition wall member 14 are positioned on the lower case 11 and temporarily fixed in place by resistance welding (for instance, spot-welding or projection welding), and the peripheral wall 15 a of upper case 15 is coupled with the upright flange 11 b of lower case 11 and positioned at its inward projections by engagement with the upper end of upright flange 11 b to enclose the whole upper side of lower case 11 . Thereafter, the lower case 11 is turned to be placed upward in reverse, and the one end of fuel supply pipe 16 is inserted into the flanged opening 15 d of upper case 15 . In such a condition, a filler metal is placed at portions necessary for brazing the lower and upper cases 11 and 15 and the fuel supply pipe 16 .
The component parts 11 ˜ 16 assembled as described above are loaded in a furnace and heated for brazing. In this process, the component parts 11 , 12 , 14 ˜ 16 are brazed in a liquid-tight manner, and the brackets 13 are brazed to the lower case 11 . In this embodiment, copper is used as the filler metal. Although the air in chamber B is expanded by heating in the furnace, the vent hole 11 d is useful to communicate the air chamber B with the atmosphere thereby to prevent deformation of the partition wall member 14 of thin thickness caused by increase of pressure in the air chamber B. This is effective to avoid the occurrence of difference in damper function of pressure pulsations of each fuel delivery pipe.
The brazed fuel delivery pipe 10 is taken out from the furnace and cooled at a normal temperature. Thereafter, a portion of lower case 11 around the outside end 11 d 1 of vent hole 11 d is locally heated and melted by laser-beam so that at least a portion 11 d 2 of vent hole 11 d is filled with melted mother metal of lower case 11 under the capillary action and that the vent hole is closed by cooling of the mother metal to complete a product of the fuel delivery pipe 10 . During the manufacturing process, it is preferable that the fuel delivery pipe 10 and the heating device such as a laser device (at least the heating head of the device) are accommodated in a hermetic container filled with helium under approximately the same pressure as that of fuel filled in the internal space A. In such a process, the helium filled and pressurized in the internal space A is effective to decrease the stress to the partition wall member 14 caused by fuel pressure acting in the internal space A. This decreases the occurrence of damage of the partition wall member 14 .
When the fuel pressure in the fuel delivery pipe 10 is fluctuated by open-and-close operation of the fuel injection valve, the top wall 14 a of partition wall member 14 forming the largest area of the air chamber B in the internal space A is flexible to absorb the pressure pulsations of fuel thereby to decrease disorder of the injection amount of fuel. This is effective to improve the fuel-air ratio and to eliminate vibration of the fuel delivery pipe 10 and unwanted noises. In the manufacturing process described above, the cylindrical vent hole 11 d is formed smaller in diameter than half the thickness of lower case 11 , and the mother metal of lower case 11 around the vent hole 11 d is locally melted by laser beam and cooled to close the vent hole 11 d after the component parts of the fuel delivery pipe were brazed in a liquid-tight manner. Thus, the vent hole 11 d can be sealed without any cap member used in a conventional fuel delivery pipe. This is useful to reduce the number of component parts and the manufacturing cost of the fuel delivery pipe.
In the fuel delivery pipe, each injection socket 12 is placed at a one-sided position in the width direction across the longitudinal direction of the bottom wall 11 a of lower case 11 , and the partition wall member 14 is placed at an opposite-sided position to each injection socket 12 in the width direction to occupy the greater part of bottom wall 11 a of lower case 11 in the longitudinal direction. With such arrangement of each injection socket 12 and partition wall member 14 , the capacity of air chamber B formed by the partition wall member 14 can be increased to reduce disorder in the injection amount of fuel. In this first embodiment, the injection socket 12 is assembled with the lower case 11 in such a manner that the cylindrical portion 12 b smaller in diameter than the bottomed cylindrical body 12 a separately formed from the lower case 11 is engaged with the mounting hole 11 c of lower case 11 . With such assembly of the injection socket 12 , the tip of cylindrical portion 12 b is projected into the interior of fuel delivery pipe 10 without any interference with the partition wall member 14 forming the air chamber B. Accordingly, the width of partition wall member 14 can be enlarged to increase the capacity of air chamber B thereby to further reduce disorder in the injection amount of fuel. Although in the first embodiment, all the three injection sockets 12 are aligned at the one-sided position, only the central injection socket 12 may be placed at the one-sided position while the other injection sockets 12 may be placed at an appropriate position.
In the fuel delivery pipe, the section of upper case 15 across the longitudinal direction is rounded at its whole corner and formed in a two stepped trapezoid. With such configuration of the cross-section of upper case 15 , an inwardly curved portion 15 b 1 formed along the longitudinal direction of upper case 15 displaces in a direction of its thickness in accordance with fluctuation of fuel pressure in the internal space A to absorb pressure pulsations of fuel in the internal space A. Since the pressure pulsations of fuel in the internal space A are absorbed by displacement of the curved portion 15 b 1 in addition to suppression caused by fluctuation of the capacity of the air chamber B, disorder in the injection amount of fuel is further reduced. In a modification of the fuel delivery pipe, the ceiling wall 15 b of upper case 15 may be flattened without curved portion 15 b 1 . In such a modification, the partition wall member 14 is brazed at its radial flange 14 c to an inner surface of the flat ceiling wall in a liquid-tight manner to form the air chamber B, and the vent hole of small diameter is formed in the ceiling wall 15 b for communication with the atmosphere and closed by the mother metal of upper case 15 locally melted by the laser beam as in the first embodiment.
Disclosed in FIGS. 5˜8 is a second embodiment of a fuel delivery pipe in accordance with the present invention. The fuel delivery pipe 10 in the second embodiment is comprised of elongate lower and upper cases 11 and 15 brazed with each other in a liquid-tight manner. Four injection sockets 12 are integrally formed with the lower case 11 . The hollow partition wall member 14 is divided into three pieces and arranged among the injection sockets 12 in a longitudinal direction.
In this second embodiment, the four injection sockets 12 each are in the form of a bottomed cylindrical body formed integrally formed with the bottom wall of lower case 11 by drawing and equally spaced in the longitudinal direction of lower case 11 . The bottom wall of each injection socket 12 is formed with an opening 12 c for communication with an internal space A. The divided hollow partition wall members 14 each are in the form of an elongate strip in cross-section. The height of periphery of each hollow partition wall member 14 is larger than the width across the longitudinal direction of top wall 14 a . The divided hollow partition members 14 each are brazed to the bottom wall 11 a of lower case 11 in a liquid-tight manner to form an air chamber B. The injection sockets 12 each are placed at a position slightly sided from the divided hollow partition wall members 14 . The bottom wall 11 a of lower case 11 is formed with three vent holes 11 d at each position corresponding with the hollow partition wall members 14 for communication with the atmosphere.
As shown in FIGS. 7 and 8 , the cross-section of upper case 15 is asymmetrically formed in stepped width and height. The upper case 15 is rounded at its whole corner and formed rectangular in cross-section at its right end portion to enlarge the sectional area of internal space A. The other components of the fuel delivery pipe are substantially the same as those in the first embodiment.
In the fuel delivery pipe of the second embodiment, mainly the peripheral walls 14 b of each hollow partition wall member 14 are flexible in accordance with fluctuation of fuel pressure in the internal space A. The flexible peripheral walls 14 b are provided at opposite sides of each hollow partition wall member 14 . As the area of the flexible peripheral walls 14 b is increased more than that of the flexible top wall 14 a of the single hollow partition wall member 14 in the first embodiment, the pressure pulsations of fuel in the internal space A are more effectively absorbed to reduce disorder of the injection amount of fuel for improvement of the air-fuel ratio and to eliminate vibration and unwanted noises. As the fuel delivery pipe is manufactured without any cap member used in a conventional fuel delivery pipe, the manufacturing cost can be reduced, and the appearance of the product can be enhanced.
As the upper case 15 is made approximately in a straight form to enclose the divided hollow partition wall members 14 and the injection sockets 12 arranged in the lateral width of each partition wall member 14 , the manufacturing cost of the fuel delivery pipe can be reduced. The inwardly projected portions 15 b 1 , 15 b 2 of upper case 15 in cross-section are displaced in the thickness direction of upper 15 in accordance with fluctuation of fuel pressure in the internal space A to more effectively absorb the pressure pulsations of fuel.
In the manufacturing process, the component parts 12 , 13 and 14 are temporarily fixed by spot-welding in place on the lower case 11 and filler metals are preplaced on portions necessary for brazing. Thereafter, the upper case 15 is coupled at its peripheral wall 15 a with the upright flange 11 b of lower case 11 after insertion of the fuel supply pipe 16 and filler metals are preplaced on portions necessary for brazing. Thus, all the component parts 11 ˜ 16 are brazed at the same time in the furnace. In a practical embodiment of the present invention, the component parts 12 , 13 and 14 may be preliminarily brazed to the lower case 11 , and thereafter, the upper case 15 may be coupled at its peripheral wall 15 a with the upright flange 11 b of lower case 11 and brazed to the lower case 11 . In such a case, the brackets 13 and partition wall members 14 may be fixed in place by seam welding substituted for brazing.
Although in the manufacturing process described above, the vent hole 11 d was sealed by the mother metal of lower case 11 locally melted by laser beam, the vent hole 11 d may be sealed by a filler metal melted by laser beam, torch for TIG welding or other heating means.
Illustrated in FIGS. 9˜11 is a third embodiment of a fuel delivery pipe with damper function in accordance with the present invention. In this third embodiment, an elongate main body of the fuel delivery pipe 10 is comprised of lower and upper cases 11 and 15 brazed to each other in a liquid-tight manner as in the second embodiment. The cross-section of the main body is the same as that in the first embodiment. The component parts of the fuel delivery pipe 10 are substantially the same as those in the first embodiment, except for an elongate hollow partition wall member 18 of flattened cylindrical form in cross-section jointed at its opposite ends to the peripheral wall 15 a of upper case 15 to form the air chamber B.
As shown in FIG. 10 , the cylindrical portion of partition wall member 18 has flat side faces 18 a opposed to one another. As shown in FIG. 9 , the cylindrical portion of partition wall member 18 is formed at its left end with a radial flange 18 b , and the upper case 15 is provided at its right end with a holder 18 c of reversed U-letter form in cross-section for engagement with the flat side faces 18 a of partition wall member 18 . The holder 18 c is brazed or welded to the inner surface of upper case 15 . A vent hole 15 f is formed in the left end of upper case 15 for communication with the interior of the cylindrical portion of partition wall member 18 in the same manner as in the foregoing embodiment.
Before the upper case 15 is brazed with the lower case 11 , the partition wall member 18 is inserted in the upper case 15 in parallel therewith and engaged with the holder 18 c at its right-side end and with the peripheral wall 15 a of upper case 15 at its radial flange 18 b . In such a condition, a filler metal is pre-placed on the portions to be brazed. Thereafter, the upper case 15 is coupled with the upright flange 11 b of lower case 11 b at its peripheral wall 15 a , and the fuel supply pipe 16 is inserted into the upper case 15 . Thus, the assembly of the component parts is brazed in the furnace in a condition where a filler metal was pre-placed on a portion of fuel supply pipe 16 to be brazed. With such a manufacturing process, the partition wall member 18 is brazed to the internal surface of the peripheral wall 15 a of upper case 15 at its opposite ends, and the air chamber B formed in the partition wall member 15 is communicated with the atmosphere through the vent hole 15 f . After the fuel delivery pipe 10 is taken out of the brazing furnace and cooled, the vent hole 15 f is closed by the mother metal of upper case 15 locally melted by laser beam and hardened by cooling. During the manufacturing process, it is preferable that the fuel delivery pipe 10 and the heating device such as a laser device are accommodated in a hermetic container filled with helium under approximately the same pressure as that of fuel filled in the internal space.
Although in the foregoing embodiments, the vent hole 11 d was formed by cutting, a punch 20 pointed at its tip 20 a may be used to form the vent hole 11 d as shown in FIG. 12 . In this process, the punch 20 is pushed into the bottom wall 11 a of lower case 11 or the peripheral wall 15 a of upper case from its inside so that the vent hole 11 d is formed in a burring hole shape. With such a punching method, the vent hole 11 d can be formed without cutting chips and closed by local melting of the mother metal of bottom wall 11 a or peripheral wall 15 a even if the vent hole is formed lager in diameter than the thickness of the bottom wall 11 a or peripheral wall 15 a.
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A fuel delivery pipe with damper function, being constructed of an elongate lower case provided at its bottom with a plurality of injection sockets for connection with fuel injection valves to be opened and closed by a controller unit; an upper case coupled with the lower case in a liquid-tight manner to form an internal space to be filled with fuel under pressure supplied from a fuel pump; a hollow partition wall member the whole periphery of which is brazed to an inner surface of the lower or upper case to form an air chamber isolated from the internal space; and a vent hole formed in the lower or upper case and sealed after communicating the air chamber with the atmosphere therethrough.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to scatterable cleaning formulations for textiles.
2. Discussion of Related Art
In addition to shampoos, powder-form cleaners above all are used for cleaning certain textiles, such as carpets and upholstery, which generally are not accessible to washing and, accordingly, are cleaned in situ. These powder-form cleaners, which are also known as dry-cleaning compositions, consist of a solid which acts as an adsorbent and a volatile liquid which is incorporated in the adsorbent and of which the function is to partly dissolve the soil on the textile. For cleaning, these formulations are scattered onto the textiles and, after evaporation of the liquid, are removed from the textile together with the soil constituents, which have been deposited onto the adsorbent, either by brushing or by vacuum cleaning. Numerous substances have been proposed in the literature both as adsorbents and as liquids for these formulations. Thus, natural polymers, such as wood flour, starch and cork powder, inorganic materials, such as kieselguhr and bentonite, and various synthetic organic polymers in powder form have been proposed as adsorbents. Organic solvents, such as gasoline or chlorinated hydrocarbons, and aqueous surfactant solutions or water/alcohol mixtures have been mentioned as suitable cleaning liquids, cf. for example DE-OSS 38 42 152, 34 37 629 and 40 27 004, which describe the use of relatively large-surface synthetic polymer particles or short-fiber cellulose in conjunction with aqueous or non-aqueous cleaning liquids.
An adequate cleaning effect is only obtained with dry cleaning formulations when, after scattering on, they are worked into the carpet by manual or machine brushing so that they come into contact with all the soil-bearing fibers. Because of the forces applied, the brushing in of the cleaning powder imposes particular demands on the strength of the carpet fibers. In many cases, roughening of the surface and the loss of carpet fibers cannot be avoided. Fluff is formed and, in certain circumstances, even impedes working in of the powder itself because some of the loose fibers wrap themselves around the lower end of the brush so that the brushing-in process has to be interrupted.
Surprisingly, the problems mentioned above are avoided if relatively large porous and rollable particles are added to the carpet cleaning formulations based on powder-form adsorbents.
DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a carpet cleaning formulation in the form of a scatterable composition which contains an aqueous cleaning liquid, a solid powder-form adsorbent and, in addition, rollable particles of porous material, the longest dimension of these particles being more than 1 mm and up to 50 mm and the dimensions in two other spatial directions, which are perpendicular to one another and to that length, being at least 10% of this maximum length. Particularly preferred carpet cleaning formulations are those in which the rollable particles consist of a deformable material, more particularly an absorbent sponge-like material.
The presence of rollable particles reduces the wear and tear on the carpet during working-in of the scatterable formulation without any significant reduction in cleaning performance. The formation of fluff is reduced. Loose fibers and similar material, for example hairs lying on the carpet, are rolled around the particles and, accordingly, can no longer lead to clogging of the brush and hence to interruption of the working-in process. In addition, odors emitted during the cleaning process can be effectively masked by the incorporation of suitable fragrances in the porous rollable particles. Since the carpet cleaning formulation, including the rollable particles, can be completely removed by vacuum cleaning after drying, only small amounts of perfume are left on the carpet after cleaning so that only a faint odor remains. Instead of this, the bag of the vacuum cleaner is being provided to an increasing extent with a slow-release fragrance, which is desirable in many cases. The positive properties, which the scatterable cleaning formulations acquire through the addition of the rollable particles, are largely independent of the constituent material of the rollable particles. Neither are the advantages confined to the choice of special powder-form adsorbents, instead they appear to be in evidence with all the powder-form adsorbents used for scatterable carpet cleaning formulations.
Accordingly, suitable powder-form adsorbents for the carpet cleaning formulations according to the invention are, for example, wood flour in bleached and unbleached form, cellulose powder, starch, cork powder, synthetic organic polymers in powder form, such as polyethylene powder, polypropylene powder, polyurethane powder, polystyrene powder, the term "powder" in this context also encompassing fine-particle polymer fibers and ground polymer foams, for example ground polyurethane foam, ground polystyrene foam, ground urea/formaldehyde resin foam and ground phenolic resin foam. Inorganic materials may also be used as powder-form adsorbents, including for example silicon dioxide in various forms, such as precipitated silica, kieselguhr and even fine sand, aluminium oxide in powder form, ground pumice stone, aluminas, for example bentonite, and other aluminium silicates, for example zeolites X, Y and A, faujasite and hydrotalcite, also ground foam glass and fine-particle soluble salts, such as sodium borate and sodium chloride. The particle size of these powder-form adsorbents is preferably between about 0.01 mm and 1 mm and more preferably between 0.02 and 0.3 mm. Adsorbents from the group consisting of wood flour, cellulose powder, water-insoluble cellulose derivatives, silica, zeolite, ground polyurethane foam and ground urea/formaldehyde resin foam are preferred.
The rollable particles present in the formulations according to the invention may be regularly or irregularly shaped particles. The crucial aspect is that the shape of the particles should be such that, during working-in of the carpet cleaning formulation, the particles are able to roll under the brush swept over the carpet. Accordingly, suitable particle shapes are spheres, cylinders, ellipsoids, egg shapes or even irregular shapes such as are formed, for example, by agglomeration of relatively small particles into granules. However, in the case of elastic and readily deformable materials in particular, even relatively angular particles, including cubes and squares, can be rollable and hence suitable for the formulations according to the invention. The size of the rollable particles should on average be distinctly larger than the particle size of the powder-form adsorbents. Thus, the longest spatial dimension of the particles should be more than 1 mm and preferably more than 3 mm and may be up to 50 mm and preferably up to 10 mm. In the two other spatial directions, which are perpendicular to one another and to that length, the particle dimensions should be at least 10% and preferably at least 20% of this maximum length.
The rollable particles may consist of various materials. Suitable materials are, for example, wood, vegetable fibers, such as coconut fibers, cellulose and cotton linters, cork, rubber, light-colored peat, starch and starch products, for example from the production of cereals, up to and including barley roots, a waste product from malt factories. Suitable synthetic organic materials are, for example, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyurethane, polyacrylate, polyester, polycarbonate, polyamide and polysiloxane. Suitable inorganic materials are various silicates, silica in various forms, aluminium oxide, aluminium silicates, for example zeolites X, Y and A, faujasite and hydrotalcite and also foam glass. The rollable particles preferably consist predominantly or completely of cellulose, viscose, natural sponge or open-cell foam plastics.
The particles can be produced on the one hand by size-reduction of relatively large pieces of material, for example by cutting up or by grinding, or on the other hand by agglomeration of fine-particle materials by various agglomeration techniques. More particularly, the particles of wood, cork, peat and natural sponge and the particles of synthetic organic polymers are generally obtained by size reduction of relatively large pieces. The particles consisting of synthetic organic polymers are preferably obtained from foamed material or from fleece-like material or from pieces of fabric. Foam glass is also preferably brought to the required size by size reduction. By contrast, the other inorganic materials mentioned and also starch- and cellulose-containing materials are advantageously converted into rollable particles of the required size by agglomeration of relatively fine particles. The choice of the agglomeration process and the binder materials necessary, if any, is of secondary importance. The macroscopic pore volume of the rollable particles is preferably between about 0.3 and 50 mug and more preferably between 1 and 30 ml/g.
The content of rollable particles in the formulations according to the invention can be relatively small because even a few particles are sufficient to obtain the required effect. Thus, the percentage content of rollable particles in the formulations according to the invention is preferably between about 0.1 and 10% by weight and more preferably between 0.1 and 2% by weight, based on the formulation as a whole.
In the most simple case, the cleaning liquid present in the formulations according to the invention may be water and only water although, in many cases, the cleaning liquid contains other auxiliaries which enhance the cleaning effect or are otherwise useful in the practical application of the formulations. The quantity of liquid is gauged in such a way that it can be taken up by the solid constituents of the formulations, thus guaranteeing their scatterability. For this reason, the content of water in the formulations is preferably from 25 to 75% by weight and more preferably from 30 to 70% by weight, based on the formulation as a whole.
The formulations according to the invention may advantageously contain organic solvents and/or surfactants as cleaning-enhancing additives in the cleaning liquid. Suitable organic solvents are both water-miscible and water-immiscible solvents providing they do not attack the textiles and are sufficiently volatile to evaporate in a short time after application of the formulations to the textiles. In addition, it is important when selecting the solvents to ensure that they have sufficiently high flashpoints in the final product mixture and are toxicologically safe. Suitable solvents are alcohols, ketones, glycol ethers and hydrocarbons, for example isopropanol, acetone, ethers of monoethylene and diethylene glycol and of mono-, di- and tripropylene glycol with boiling points of 120° C. to 250° C. and gasolines with a boiling range of 130° to 200° C., more particularly low-aromatic fractions, and mixtures of these solvents. C 2-3 alcohols, propylene glycol ethers, gasolines and mixtures thereof are preferably used. The quantity of organic solvents in the formulations according to the invention is preferably not more than 20% by weight and, in particular, between 2 and 15% by weight.
Although the formulations have a very good surface cleaning effect in no way inferior to that of commercial formulations, even without the addition of surfactants, the removal of stains can be further improved in the majority of cases by the addition of surfactants. In general, a surfactant addition of up to 10% by weight is sufficient. The formulations preferably contain 0.05 to 5% by weight and, more particularly, no more than 1% by weight of surfactants. Of the large number of known surfactants, substances which dry off to form a solid brittle residue, optionally together with other non-volatile constituents of the formulations, are particularly suitable. The surfactants may emanate from the classes of anionic or nonionic surfactants, although anionic surfactants are preferably used.
Suitable nonionic surfactants are, in particular, adducts of 1 to 30 and preferably 4 to 15 moles of ethylene oxide per mole of a long-chain compound containing 10 to 20 carbon atoms from the group of alcohols, alkylphenols, carboxylic acids and carboxylic acid amides. Corresponding compounds in which propylene oxide is added on instead of part of the ethylene oxide are also suitable. Of particular importance are the adducts of ethylene oxide with long-chain primary or secondary alcohols such as, for example, fatty alcohols or oxoalcohols and with monoalkylphenols or dialkylphenols containing 6 to 14 carbon atoms in the alkyl groups. Other suitable nonionic surfactants are the long-chain amine oxides and the fatty alkyl (poly)glycosides containing 1 to 3 glycose units in the molecule.
Particularly suitable anionic surfactants are those of the sulfate or sulfonate type, although other types, such as soaps, long-chain N-acyl sarcosinates, salts of fatty acid cyanamides or salt of ether carboxylic acids obtainable from long-chain alkyl or alkylphenyl polyglycol ethers and chloroacetic acid, may also be used. The anionic surfactants are preferably used in the form of the sodium salts.
Particularly suitable surfactants of the sulfate type are the sulfuric acid monoesters of long-chain C 10-20 primary alcohols of natural and synthetic origin, i.e. the sulfuric acid monoesters of fatty alcohols, for example cocofatty alcohols, tallow fatty alcohols, oleyl alcohol, or C 10-20 oxoalcohols and sulfuric acid monoesters of secondary alcohols with the same chain length. The sulfuric acid monoesters of aliphatic primary alcohols, secondary alcohols or alkylphenols ethoxylated with 1 to 6 moles of ethylene oxide are also suitable, as are sulfated fatty acid alkanolamides and sulfated fatty acid monoglycerides.
The surfactants of the sulfonate type are, primarily, sulfosuccinic acid monoesters and diesters containing 6 to 22 carbon atoms in the alcohol components, alkyl benzene sulfonates containing C 9-15 alkyl groups and esters of α-sulfofatty acids, for example the α-sulfonated methyl or ethyl esters of hydrogenated coconut oil, palm kernel oil or tallow fatty acids. Other suitable surfactants of the sulfonate type are the alkane sulfonates obtainable from C 12-18 alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition onto olefins and the olefin sulfonates, i.e. mixtures of alkene and hydroxyalkane sulfonates and also disulfonates obtained, for example, from long-chain monoolefins with a terminal or internal double bond by sulfonation with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products.
C 12-18 fatty alcohol sulfates, salts of sulfosuccinic acid monoesters containing 16 to 20 carbon atoms in the alcohol component and mixtures of these surfactants are particularly preferred.
In addition to the components already mentioned, the formulations according to the present invention may also contain small quantities of other auxiliaries and additives typically encountered in textile and carpet cleaning compositions. Examples of such auxiliaries and additives are antistatic components, for example inorganic salts and quaternary ammonium compounds, optical brighteners, resoiling inhibitors, for example polyacrylates, additives which improve scatterability and dispersibility, preservatives and perfume. These auxiliaries and additives are normally used in total quantities of no more than 10% by weight, preferably in quantities of no more than 5% by weight and more preferably in quantities of 0.01 to 2% by weight, based on the formulation as a whole.
A particularly preferred formulation contains cellulose powder as the powder-form adsorbent, preferably in quantities of around 40 to 50% by weight, flakes of viscose sponge as the rollable particles, preferably in quantities of around 0.1 to 2% by weight, sodium olefin sulfonate as surfactant, preferably in quantities of around 0.2 to 1.5% by weight, low-aromatic gasoline as solvent, preferably in quantities of around 1 to 10% by weight, and water.
The production of the formulations according to the invention does not involve any significant outlay on equipment. Simple mixing units, such as blade or drum mixers are suitable, the rollable particles, the powder-form adsorbent and any other fine-particle solid components are initially introduced into the mixer and are then sprayed in motion with the cleaning liquid in which other constituents are optionally dissolved.
The textiles and carpets are cleaned by scattering the cleaning formulations according to the invention onto the textiles either by hand or by means of a suitable distributor and then rubbing them more or less intensively into the textiles, for example by means of a sponge, a brush or a board. In general, the working-in times are between 0.3 and 5 minutes and preferably between 0.5 and 3 minutes per square meter. The residues are mechanically removed from the textiles, for example by brushing and/or vacuum cleaning. For cleaning relatively large textile surfaces, the formulations according to the invention are applied in quantities of around 2 to around 150 g/m 2 , depending on the fullness of the textiles and the degree of soiling, although considerably larger quantities may also be used in the treatment of relatively small pieces of textiles or for the removal of individual stains. For cleaning carpets, the formulations are normally applied in quantities of around 10 to around 100 g/m 2 . The process as a whole may be carried out largely manually, for example in the home, although it is also possible to carry out rubbing in and, optionally, other steps by means of suitable machines, for example combined distributing and brushing machines, so that the process is equally suitable for use in the institutional sector.
EXAMPLES
The formulations listed with their individual components in the following Table were prepared in quantities of 10 kg in a paddle mixer, the adsorbents and the rollable particles being introduced first and then being sprayed with a solution of the other components in water. Mixing was continued until a homogeneous free-flowing product was formed.
TABLE______________________________________Composition of the Formulations (in % by weight) 1 2 3 4 5 6______________________________________Beechwood cellulose powder 43.0 46.0 42.5 47.0Urea/formaldehyde resin 72.0 88.0foam, powdered(75% moisture)Chopped viscose sponge 0.3 0.6 1.0 3.0Zeolite agglomerate 2.5 4.7Na lauryl sulfate 0.8 0.3Na olefin sulfonate 0.8 1.1Ethanol 5.0Isoparaffin 1.0Water, perfume, preservativeto 100% by weight______________________________________
The ingredients listed in the Table are the following materials:
Beechwood cellulose powder:
Arbocel B 800×, a product of Rettenmaier, apparent density 105-135 g/l
Urea/formaldehyde resin foam, powdered:
Moist material containing 75% by weight H 2 O maximum particle size distribution at around 0.03 mm, apparent density 70 g/l.
Chopped viscose sponge:
Sponge cloth material of the type used for cleaning kitchens (cotton content 50%) was chopped up in a cross-cutting machine into flakes measuring 2.5×2.0×2-8 mm. Apparent density around 90 g/l.
Zeolite agglomerate:
Baylith W 894, granules of zeolite X-Na, binder-free, spherical, particle size 1-4 mm.
Isoparaffin:
Isopar M, a product of Exxon (gasoline), boiling range 205°-255° C.
Cleaners 1 to 6 according to the invention were performance tested against artificial pigment soils and hairy coverings and in regard to the roughening of the treated carpet material and, at the same time, were compared with cleaners which, instead of the rollable particles of viscose sponge or zeolite agglomerate, additionally contained a corresponding quantity of the particular powder-form adsorbent, but were otherwise of the same composition. Cleaning performance against artificial pigment soils was tested on polyamide cut-pile carpets. The cleaners according to the invention showed substantially the same performance as the cleaners without rollable particles. Against hairy coverings (scattered-on mixture of cotton wool, hairs and wool fibers), the cleaners according to the invention were distinctly superior. Whereas, in the case of the Comparison Examples, some of the fibers became trapped in the brush, they wrap themselves around the rollable particles of the cleaners according to the invention and could to be removed with them by vacuum cleaning. The roughening of the carpet material was tested on wool uncut-pile carpets. The carpets treated with the cleaners according to the invention were found on visual examination to show distinctly less roughening than the pieces of carpet treated with the comparison cleaners, i.e. the cleaners without rollable particles.
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A carpet cleaning composition comprising: (a) a powder-form solid adsorbent; (b) rollable particles of porous material, each particle having a length greater than 1 mm, and a diameter equal to at least 10% of the length of the particle; and (c) water.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to concrete fence wall installation technology and more particularly, to a concrete pile installation apparatus, which facilitates installation of concrete piles, saving much concrete pile installation labor and time.
[0003] 2. Description of the Related Art
[0004] Conventionally, a concrete fence wall is established, as shown in FIG. 1 , by: making pile holes on the ground at selected locations, and then mounting concrete piles 1 in the pile holes, and then inserting concrete slabs 3 into the longitudinal grooves 2 of each two adjacent concrete piles 1 . According to this method, concrete piles are individually installed in the pile holes. During installation, rule and wire are used to assist vertical angle and horizontal position measurement. This method has drawbacks as follows:
[0000] 1. Concrete piles are to be installed individually. Rule and wire must be used to assist vertical angle and horizontal position measurement, requiring much labor and time and increasing the installation cost.
2. If one concrete pile 1 biased in one respective pile hole 4 due to a human error, as shown in FIGS. 2 and 3 , the operators will be unable to insert concrete slabs 3 into the longitudinal grooves 2 of the corresponding concrete piles 1 accurately. In this case, the concrete pile 1 must be removed from the respective pile hole 4 and re-installed.
SUMMARY OF THE INVENTION
[0005] The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a concrete pile installation apparatus, which comprises a pile clamping unit that has stop plates arranged at different elevations and hand wheel-controlled clamping blocks disposed corresponding to the stop plates and operable to clamp concrete piles for installation and rollers that facilitate adjustment of the position of concrete piles. By means of the concrete pile installation apparatus, multiple concrete piles can be installed at a time, saving much concrete pile installation labor and time.
[0006] It is one object of the present invention to provide a concrete pile installation apparatus, which further comprises two racks that use hydraulic cylinders and rollers to support the pile clamping unit, allowing adjustment of the pile clamping unit and the clamped concrete piles vertically as well as horizontally.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates the installation of a concrete fence wall according to the prior art.
[0008] FIG. 2 is a schematic drawing showing one concrete pile biased in the pile hole according to the prior art.
[0009] FIG. 3 is a schematic drawing showing a concrete pile biased and concrete slab installation failed according to the prior art.
[0010] FIG. 4 is an exploded view of a concrete pile installation apparatus in accordance with the present invention.
[0011] FIG. 5 is a schematic drawing showing an application status of the present invention.
[0012] FIG. 6 is a schematic drawing of a part of the present invention, showing one concrete pile supported in the pile clamping unit and adjusted.
[0013] FIG. 7 is a schematic top view of a part of the present invention, showing a concrete pile clamped in the pile clamping unit.
[0014] FIG. 8 is a schematic drawing of the present invention, showing the pile clamping unit supported on the racks and adjusted horizontally.
[0015] FIG. 9 is an exploded view of an alternate form of the rack in accordance with the present invention.
[0016] FIG. 10 is a schematic front view of the present invention, showing an operation status of the alternate form of the rack.
[0017] FIG. 11 is a schematic side view of the present invention, showing an operation status of the alternate form of the concrete pile installation apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIGS. 4-8 , a concrete pile installation apparatus in accordance with the present invention is shown comprising two racks 20 and a pile clamping unit 10 .
[0019] The pile clamping unit 10 comprises an upper beam 101 , a lower beam 102 , a plurality of stop plates 15 symmetrically fixedly located on each of the upper and lower beams 101 ; 102 , a plurality of plurality of screw holders 11 symmetrically fixedly located on each of the upper and lower beams 101 ; 102 corresponding to the stop plates 15 , a screw rod 12 rotatably mounted in each of the screw holders 11 , a clamping block 13 fixedly located on one end of each screw rod 12 , a hand wheel 14 fixedly located on the other end of each screw rod 12 and operable to rotate the associating screw rod 12 and to further move the associating clamping block 13 toward or away from the associating stop plate 15 for clamping a concrete pile 1 or releasing the clamped concrete pile 1 , a plurality of rollers 16 pivotally mounted on the upper beam 101 and respectively disposed between the stop plates 15 and the screw holders 11 at the upper beam 101 , and two side plates 17 symmetrically disposed at two opposite lateral sides and supportable on the racks 20 . Each rack 20 comprises a flat top 21 , two vertical hydraulic cylinders 22 mounted on the flat top 21 and a roller 23 supported on the vertical hydraulic cylinder 22 and movable up and down by the vertical hydraulic cylinders 22 . The two side plates 17 of the pile clamping unit 10 are supported on the rollers 23 of the racks 20 .
[0020] When in use, as shown in FIG. 6 , place the pile clamping unit 10 horizontally on the ground, and then set concrete piles 1 between the stop plates 15 and the clamping blocks 13 respectively for enabling the concrete piles 1 to be supported on the rollers 16 and adjusted to the desired position, and then operate the hand wheels 14 to rotate the associating screw rods 12 and to further move the associating clamping blocks 13 toward the associating stop plates 15 , thereby clamping the concrete piles 1 . Thereafter, use a steel rope 18 and a crane to lift the pile clamping unit 10 and the clamped concrete piles 1 , as shown in FIGS. 5 and 8 , for enabling the concrete piles 1 to be inserted vertically into respective pile holes 4 on the ground. At this time, the two side plates 17 of the pile clamping unit 10 are respectively supported on the rollers 23 of the racks 20 . Thereafter, operate the vertical hydraulic cylinder 22 to adjust the elevation of the rollers 23 and the pile clamping unit 10 , thereby adjusting the insertion depth of the concrete piles 1 in the respective pile holes 4 . Further, because the pile clamping unit 10 is supported on the rollers 23 of the racks 20 , adjustment of the horizontal position of the pile clamping unit 10 is easy.
[0021] As stated above, the pile clamping unit 10 can clamp multiple concrete piles 1 at a time. Subject to the functioning of the rollers 16 and the vertical hydraulic cylinder 22 and rollers 23 of the racks 20 , the clamped concrete piles 1 can be adjusted vertically as well as horizontally to the accurate position. Therefore, the invention facilitates accurate and rapid installation of concrete piles, saving much installation labor and time.
[0022] FIGS. 9-11 show an alternate form of the rack practical for use in the installation of a non-linear or arched concrete fence wall. According to this alternate form the rack 30 comprises a flat top 31 , two vertical hydraulic cylinders 32 mounted on the flat top 31 , and a roller 33 supported on the top end of the reciprocating rod 320 of each vertical hydraulic cylinder 32 and movable up and down the reciprocating rod 320 of the vertical hydraulic cylinders 32 , a pile holder 34 for holding a concrete pile 1 , and two supplementary rollers 35 located on the bottom side of the pile holder 34 and respectively supported on the rollers 33 at the reciprocating rods 320 of the vertical hydraulic cylinders 32 . During application, as shown in FIGS. 10 and 11 , a concrete pile 1 is supported on the pile holder 34 . By means of rotating the rollers 33 , as shown in FIG. 10 , the concrete pile 1 can be adjusted leftwards or rightwards to the desired position. By means of rotating the supplementary rollers 35 , as shown in FIG. 11 , the concrete pile 1 can be adjusted forwards or backwards to the desired position.
[0023] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A concrete pile installation apparatus includes a pile clamping unit having stop plates arranged at different elevations and hand wheel-controlled clamping blocks disposed corresponding to the stop plates and operable to clamp concrete piles for installation and rollers that facilitate adjustment of the position of concrete piles, and two racks that use hydraulic cylinders to support the pile clamping unit and to adjust the elevation of the pile clamping unit and the clamped concrete piles.
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RELATED APPLICATION
This application is a Continuation of U.S. patent application Ser. No. 13/212,881, entitled System and Method for In-Place Data Migration, filed on Aug. 18, 2011, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/378,516, entitled System and Method for In-Place Data Migration, filed on Aug. 31, 2010, the contents both of which are incorporated herein by reference in their entirety for all purposes.
TECHNICAL FIELD
The present invention relates to data storage and digital content management and more particularly, to a cost-effective system and method for in-place or post-facto migration of data to cloud-based storage services.
BACKGROUND INFORMATION
It is important for companies to find cost effective ways to manage their digital file storage. Although it may seem that file storage is inexpensive, 80% or more of the total cost of ownership is in managing and administering that storage. Most organizations' need for file storage is growing at 40% to 50% per year, along with the cost to manage that storage. Today, many companies have so much data that moving it from place to place can be cost-prohibitive.
A number of storage software vendors provide solutions that will store and organize data. Examples of such solutions in include conventional NAS, SAN or DAS storage devices which are typically deployed and maintained by an enterprises IT department. In addition, there is currently a trend towards public and private cloud-based or virtual data stores and associated name spaces supported internally and externally, and accessed by users via a Wide Area Network such as the Internet and by legacy protocols such as CIFS and NFS. Examples of these approaches include the Microsoft® SharePoint™, ByCast, and Xanet services, etc.
One of the drawbacks the Storage Industry has today is that, unlike in the past when file data was comparatively small could be easily copied from one location to another, today's enterprises often have too much data to move other than by necessity. This may be particularly problematic for relatively large users attempting to migrate from conventional user-supported NAS, SAN or DAS storage devices, to the aforementioned cloud-based or virtual data stores. Indeed, for an enterprise-class customer that may have several terabytes (or more) of data, such movement may not be realistically feasible, since the resources required for such a data migration may approach or exceed the available resources of their IT infrastructure.
For example, the US military has recently attempted to standardize on SharePoint™. In total there are approximately 3 million users, hundreds of petabytes of data and trillions of files. Currently, it may be possible to load a trillion records into a database. Indeed, in some applications it may be possible to manipulate a billion records using a conventional desktop computer. However, it is impractical, if not substantially impossible, to move 100 petabytes of data electronically from point A to point B in any reasonable period of time or affordable cost.
Accordingly, what is needed is a cost-effective system and method for the virtual, or post-facto migration of relatively large amounts of data to cloud-based data sharing services or other content management systems.
SUMMARY
Aspects of the present invention include methods and systems for the in-place or post-facto migration of data to a cloud-based data storage service or other virtual storage environment. The system includes a Cloud Storage Import Utility (CSIU) device including a file selection module and configured to generate a user interface. The user interface is configured for allowing a storage administrator to select one or more files, file folders, or shares to be to be published to the cloud and optionally migrated from a current storage device to another storage service, and for providing an indication of said selection. The CSIU is configured to capture metadata for the selected files or file folders. The CSIU also provides one or more commands understandable by the cloud-based data storage service, to cause the metadata to be migrated to the cloud-based data storage service independently of the files or file folders, so that they are usable by the cloud-based storage service without being moved to the cloud-based storage service.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:
FIGS. 1 and 2 are block diagrams of systems of the prior art;
FIG. 3 is a block diagram of an embodiment of a system and method of the present invention;
FIG. 4 is a block diagram of an alternate embodiment of a system and method of the present invention; and
FIGS. 5-15 are screen displays of an exemplary operation of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An aspect of the invention was the realization that data storage for large scale, enterprise-level applications presents issues that are substantially different from those of relatively small scale applications. The instant inventor also realized that contrary to conventional wisdom among much of the relevant industry, metadata and the underlying data to which it pertains, may be separated from one another without sacrificing desired functionality.
Turning now to FIG. 1 , can be seen that in order to use conventional cloud-based data storage services 28 , all of the data, i.e., the underlying data bits and their corresponding metadata, must be moved from an original location (e.g., data store 14 ) into the cloud-based service 28 . As shown in FIG. 2 , once in service 28 , the data may be transferred to a remote data store, such as via Sharepoint's Remote Blob Storage feature, shown at 14 ′, where it may be accessed by service 28 . However, both of these scenarios require the initial upload of the underlying data, as well as its corresponding metadata, to service 28 .
Turning now to FIG. 3 , an embodiment of the present invention will be described in connection with an exemplary system 10 . As shown, system 10 may be accessed by a storage administrator, via a user device 12 , which may take the form of a computer, laptop, PDA, Smart phone or the like. Other examples of user devices 12 include a workstation, personal computer, personal digital assistant (PDA), wireless telephone, or any other suitable computing device including a processor, a computer readable medium upon which computer readable program code (including instructions and/or data) may be disposed, and a user interface, all of which require or may be used by a storage administrator to migrate data to a cloud-based or virtual data storage service for primary and/or archiving storage. A similar device usable by an end-user, shown as end-user device 12 ′, may be used in a conventional manner to access files administered by embodiments of the present invention.
As shown, the user device 12 is communicably couplable via a network 18 , e.g., a Wide Area Network such as the Internet, to a storage device 14 that may be used for primary (day to day) storage, and/or that may also be used for long term storage or archiving. The primary storage and long-term or archiving storage may be performed on two different areas of the same physical storage device 14 or alternatively, may be performed on two physically different and/or remotely located storage devices 14 .
Storage device 14 may include any number of storage devices, including, but not limited to, Network Attached Storage (NAS) such as those available from EMC Corporation (Hopkinton, Mass., USA) and NetApp (Sunnyvale, Calif., USA), Storage Area Network (SAN) devices such as, but not limited to, those from EMC Corporation (Hopkinton, Mass., USA), and direct attached storage devices (DAS) such as, but not limited to, devices running the Microsoft Windows Server operating system.
A cloud-based (virtual) data store/storage system 28 is also shown communicably coupled to network 18 . This storage system 28 may take the form of any number of commercially available services, such as the aforementioned Microsoft® SharePoint™, ByCast, and Xanet services, etc. For ease of explication, the embodiments disclosed herein will be shown and described with respect to the Microsoft® Sharepoint™ service, with the understanding that these embodiments/descriptions are applicable to substantially any cloud-based or other virtual storage environment data store/storage system currently available or which may be developed in the future.
As also shown, system 10 includes a Cloud Storage Import Utility (CSIU) 30 . This CSIU 30 is located on a server (e.g., a webserver) that may enable user access via webpage(s). This server may also perform other functions and may provide various other features to the network such as database hosting, etc. The CSIU 30 enables users, such as storage administrators, to select files, e.g., by accessing a file selection application 15 , to select files for in-place-migration from a storage device 14 to a Sharepoint system 28 . The CSIU 30 receives file selections from the file selection application 15 and then captures information (e.g., metadata) associated with the selected files. CSIU 30 is configured to then insert this captured metadata into the metadata database of the Sharepoint data store 28 . The CSIU 30 may also be configured to index (or to enable communication with Sharepoint enabling it to index) the files selected by file selection application 15 , e.g., to enable end-users to effect content-based, full text searching of the selected files via the Sharepoint interface.
It should be recognized that the file selection application 15 may be a software application, such as a version of the NTP Software Storage Investigator™ available from NTP Software (Nashua N.H.) and incorporated herein by reference, that may be modified in accordance with the teachings hereof, to permit users to designate specific files or categories of files for use by CSIU 30 . The file selection application 15 may reside directly on the server hosting CSIU 30 , or on another server or platform, including, optionally, user device 12 . It should also be recognized that storage device 14 may be substantially any data store which is remote from the Sharepoint store 28 , including, for example, a data store connected via Sharepoint's Remote Blob Storage, shown as 14 ′ in FIG. 4 .
As mentioned hereinabove, user device 12 , 12 ′, storage device 14 , 14 ′, cloud storage service 28 , and the server that holds CSIU 30 , are communicably coupled to one another over a network communication path 18 , such as the Internet. The user device 12 , 12 ′ may be any form of computing or data processing device capable of communicating via network 18 .
Terms such as “server”, “application”, “engine”, “module” and the like are each intended to refer to a computer-related component, including hardware, software, and/or software in execution. For example, an engine may be, but is not limited to being, a process running on a processor, a processor including an object, an executable, a thread of execution, a program, and a computer. Moreover, the various components may be localized on one computer and/or distributed between two or more computers. The term “cloud-based data storage” will be used herein to refer to substantially any virtual storage environment. The term “in-place migration” and/or “post-facto migration” refers to publishing or otherwise making data usable by the cloud-based storage service without having to first move the data to the cloud-based storage service.
In various embodiments, the CSIU 30 and/or file selection application 15 may provide a user interface that takes any of various forms including, but not limited to, a standard web browser based application that operates with web browsers such as, but not limited to, Microsoft Internet Explorer (IE) and Mozilla Firefox.
The CSIU 30 is an application configured to effectively translate selections made using the File Selection Application 15 e.g., using lookup tables, database, hard coded programming, configuration files or the like, into instructions or commands usable by CSIU 30 as discussed hereinabove. CSIU 30 is also configured to capture information (e.g., metadata) associated with the file selections and effectively package it with these instructions/commands for use by cloud-based service 28 . CSIU 30 may also handle appropriate security requirements, e.g., to ensure that the particular user at device 12 has requisite permissions, etc.
In particular embodiments, CSIU 30 may include a version of the NTP Software ODA™ engine commercially available from NTP Software, Inc. (Nashua, N.H., USA) and incorporated herein by reference, and which has been modified in accordance with the teachings hereof.
In a representative method of operating system 10 , a user (e.g., storage administrator) may use device 12 to access 40 the file selection application 15 of the CSUI 30 and select files or folders on primary data store 14 . The CSIU 30 may then capture information (e.g., metadata) for the selected files and/or folder(s), and translates the intended actions into instructions, including metadata, to be conveyed 42 to the Sharepoint service 28 for incorporation into the Sharepoint metadata file(s), to effect the desired in-place-migration of the selected files/folders. Thereafter, an end-user 12 ′ may query 44 the Sharepoint data store 28 , to retrieve 46 data files stored on remote data store 14 .
Turning now to FIG. 4 , an alternate embodiment of the present invention is shown as exemplary system 10 ′. System 10 ′ is substantially similar to system 10 of FIG. 3 , while also including another remote data store 14 ′ which may serve as a new repository for the underlying source data for the files/folders selected by the user via device 12 . During operation of this system 10 ′, a user (e.g., storage administrator) may use device 12 to access and select 40 files using the file selection application 15 of the CSUI 30 . The CSIU 30 may then capture information (e.g., metadata) for the selected files/folder(s), translate the intended actions into instructions, and convey 42 this information, including the metadata, to the Sharepoint service 28 . The underlying data may also be moved 43 (e.g., in response to a command sent via device 12 ) from data store 14 to the other data store 14 ′ (e.g., via Sharepoint Remote Blob Storage), where it may be handled by cloud-based service 28 . In this manner, system 10 ′ effects the desired in-place-migration of the files selected by the user, by moving them to target data store 14 ′ where they may be accessed via service 28 without ever having to be moved to the service 28 . Thereafter, an end-user 12 ′ may query 44 the Sharepoint data service 28 , to retrieve 46 data files stored on remote data store 14 ′.
A more detailed example of in-place-migration in accordance with the present invention will now be shown and described with reference to FIGS. 5-15 . Turning now to FIG. 5 , user device 12 may be used to access a particular end-user's home directory on data store 14 . In this example, the entire contents of this home directory will be selected for (in-place) migration into this user's Home Documents site on SharePoint 28 .
It should be recognized that the data files shown in this home directory on data store 14 are indexed, e.g., by the CSIU 30 using any number of conventional indexing approaches, to enable end-users to search the contents based on keywords. For example, as shown in FIG. 6 , the word “royalty” has been used to search for the EULA.doc file. The index(es) of this home directory may thus be imported into service 28 as part of the migration process, and/or the data files may be indexed by service 28 after receiving the metadata, as will be discussed in greater detail hereinbelow.
As shown in FIG. 7 , in this example, prior to file migration, the contents of the end-user's Home Documents site on Sharepoint 28 is empty.
As shown in FIG. 8 , the CSIU 30 , e.g., accessed by a storage administrator via device 12 , displays a dialog screen by which the user may select data files, e.g., by entering the source directory path of the end-user's home directory on the file server 14 , along with that of the target SharePoint site 28 . Clicking the “import” button causes the utility to perform the import by capturing and forwarding the corresponding metadata, while leaving the underlying data files in place at data store 14 . After the import/in-place-migration is complete, the SharePoint site 28 contains “links” to each file imported, such as shown in FIG. 9 .
To illustrate the items in SharePoint 28 are simply “links” to the files on file server 14 , the screenshot of FIG. 10 shows the contents of a “DragImg” Word document. This document was launched (e.g., by the end-user device 12 ′) from the “link” in the user's Home Documents site on Sharepoint 28 .
Thereafter, as shown in FIG. 11 , the title of the DragImg document file is modified from the end-user's Home directory on the original file server 14 (i.e., not through SharePoint 28 ), and then stored back to the file server 14 .
Then, the same file is opened through its “link” on SharePoint 28 . As can be seen in FIG. 12 , the title of this document shows the change made outside of Sharepoint 28 . Thus, it can be seen that the contents of the file still resides on the original file server 14 , not in the SharePoint database 28 .
Turning now to FIG. 13 , once they have been published or “migrated” as described herein, Sharepoint 28 may use its indexing service, e.g., as part of its external “Blob Storage” feature to index the files. This indexing service may be run on a schedule set by the storage administrator. Alternatively, the indexing process may be initiated manually using the “Start Full Crawl” feature as shown.
Turning to FIG. 14 , the end-user may verify successful indexing by returning to his SharePoint home directory site 28 and perform a search for the word “royalty”. As shown in FIG. 15 , the search results indicate the search string was located in the EULA.doc file, illustrating successful indexing of the files imported using the in-place-migration of the present invention.
In this manner, the present invention can interface with and can be programmed to interface with essentially any archiving application that will allow it's command set/command interface to be made known to third parties for interfacing with that archiving application.
It should be recognized that information, e.g., commands, instructions, metadata, etc., may be passed between the various components (modules) disclosed herein by any convenient means, including conventional push or pull technology, without departing from the scope of the present invention. Moreover, modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by any allowed claims and their legal equivalents.
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Methods and systems for the in-place or post-facto migration of data to a cloud-based data storage service or other virtual storage environment, include a Cloud Storage Import Utility (CSIU) device having a file selection module and configured to generate a user interface. The user interface allows a storage administrator to select one or more files, file folders, or shares to be published to the cloud and optionally migrated from a current storage device to another storage service, and for providing an indication of the selection. The CSIU is configured to capture metadata for the selected files or file folders. The CSIU also provides one or more commands understandable by the cloud-based data storage service, to migrate the metadata to the cloud-based data storage service independently of the files or file folders, so that they are usable by the cloud-based storage service without being moved to the cloud-based storage service.
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FIELD OF THE INVENTION
The present invention generally relates to a Chinese character encoding and inputting method, and particularly to the direction code for encoding Chinese characters using English alphabet and the inputting method thereof.
BACKGROUND OF THE INVENTION
Up to now, more than 700 encoding systems have been disclosed for inputting Chinese characters. However, in these systems, Chinese characters are not encoded directly using English alphabet. Thus it is still inconvenient to input and outpout Chinese characters into and from computers like alphabetic languages and to use Chinese characters in communication facilities and automatic printing systems.
Among the prior art methods, five-stroke encoding system invented by Wang Yong Min is suitable to standard keyboard, with only a few duplicate codes. However, the operators have to master 125 radicals and 25 pithy formulas defined by the inventor. And this makes non-typists shrink back at the sight of the great amount of what have to be memorized. This defect is due to the fact that the method is soly based on character forms.
With the "full-information" code invented by Du Bing Chan, an operator also has to remember 100 radicals in common use and 8 first pronounceable letters of 8 strokes. It is difficult to solve the problem of alphabetizing Chinese characters by just concerning the similar pronunciation between Chinese characters and alphabetic language, regardless of character forms. Owing to many dialects and slangs, the above method is hard to be popularized.
Although Chen Ai Wen, the inventor of "Biao Xing" (indicating form) code, discovered that there obviously exist a few letters of English alphabet in Chinese characters, he did not find this objective law: all Chinese characters are formed by letters of English alphabet piled up like toy bricks. Thus, he adopted the method for inputting Chinese characters by means of the mixture of four kinds of information associated with phonetic alphabet, numerals, component radicals and stroke blocks similar to letters, and a few letters of English alphabet to input Chinese characters in conventional way. Thus users have to memorize a lot of rules.
SUMMARY OF THE INVENTION
Accordingly, it is the object of the present invention to provide a method for encoding Chinese characters using English alphabet. The code formed with the above method is called "Direction Code".
The inventor bases his invention on such a theory that Chinese characters are of alphabetic writing. According to this theory, each Chinese character is regarded as a combination of some English letters in 42 states in which the letters are in different directions. The direction codes of Chinese characters are obtained by steps of:
constructing the letters of English alphabet that objectively exist in Chinese characters according to horizontal stroke " ", vertical stroke " ", left-slanting stroke " " and right-slanting stroke " " of Chinese characters,
decomposing Chinese characters into combinations of certain actual postures among 161 ones of the letters according to order of strokes and rules of the order of strokes, said combinations of postures being limited to 6 direction patterns, said letters being in 8 positive directions and 8 inverted ones presented by the letters respectively;
said combinations of the letters being the direction codes of the Chinese characters encoded.
Finally, these codes are stored in the memory of a computer. With the help of appropriate software, Chinese characters can be input by entering some combinations of English letters. Specifically, an external code according to the present invention is a ACSII string of 4 bytes. If the length of the code is less than 4 bytes, the code is followed by a space. An internal code according to the present invention is a compressed binary bit string of 3 bytes. Every element of an external code corresponds to 5 bits of an internal code. The distribution of the external codes is arranged according to the frequency of the characters appeared in daily use, phrases, and characters defined by the users.
The English letters adopted in the present invention have 42 states:
(a) 26 positive capital letters, including A, B, C, D, E, F, G, H, I, J,K,L,M, N, O,P,Q,R,S,T,U,V,W,X,Y and Z;
(b) 8 positive small letters, including b, f, g, h, i, r, t and y;
(c) 4 inverted capital letters corresponding to 4 positive capital letters F, G, Q and S, including , , and ;
(d) 4 inverted small letters corresponding to 4 positive small letters h, n, r and y, including , , and .
The following rules of the order of strokes are used:
(a) get a letter directly;
(b) horizontal first, and then vertical;
(c) left-slanting first, and then right-slanting;
(d) from left to right;
(e) from left to middle, and then right;
(f) from top left, top middle, top right to bottom left, bottom middle, bottom right;
(g) from top to bottom;
(h) from top to middle, and then bottom;
(i) from left top, left middle, left bottom to right top, right middle, right bottom;
(j) from outside to inside;
(k) from outside to inside, and then seal;
(l) from left top to right bottom;
(m) from right top to left bottom;
(n) from middle to both sides.
The inputting method of Chinese characters according to the present invention has the following features and effects:
1. It is the full information, which exist definitely and objectively in Chinese characters, such as the five elements including strokes, variable letters of English alphabet constructed with strokes, directions of letters, the order of strokes, and direction patterns, that is developed and utilized in the present invention, but not only one-sided information, such as character forms, or character pronunciation, or character angles.
2. The present invention discloses the reality that Chinese characters are composed of 161 different postures of the letters of English alphabet. That is, Chinese characters are constructed with letters of English alphabet directly. This is advantageous to the application of Chinese characters in computers, as alphabetic writing in block form.
3. With the method according to the present invention, Chinese characters are input via a standard keyboard, with low rate of duplicate codes.
For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) to 1(z) show the direction postures of 26 positive capital letters A, B, C, . . . , Z in 8 directions, which are used in the inputting method of Chinese characters according to the present invention;
FIGS. 2(a) to 2(h) show the direction postures of 8 positive small letters b, f, g, h, i, r, t, y in 8 directions, which are used in the inputting method of Chinese characters according to the present invention;
FIGS. 3(a) to 3(d) show the direction postures of 4 inverted capital letter; , , and in 8 directions which are used in the inputting method of Chinese characters according to the present invention;
FIGS. 4(a) to 4(d) show the direction postures of 4 inverted small letters , , and in 8 directions, which are used in the inputting method of Chinese characters according to the present invention; and
FIG. 5 shows the correspondence between the 42 states of the letters used in the present invention and the keys on the standard English keyboard.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described by way of detailed examples and in the order of strokes in calligraphy.
1. The relationship among the pastures, direction patterns and directions of letters in Chinese characters and the corresponding appearance
Though there are about 60 thousand characters in Chinese language, only less than 8 thousand of them are frequently used. There may be 336 postures of the letters which objectively exist in the thousands of frequently-used characters (42 states * 8 directions). However, the inventor discovered that only 161 not 336 postures, as shown by bold arrows in FIGS. 1(a) to 1(z) , 2(a) to 2(h), 3(a) to 3(d) and 4(a) to 4(d), appear in the strokes of these characters. The combinations of these postures are limited to 6 direction patterns, namely, east, south, west, north, mixed, as well as mixed and changed directions.
b 2. Examples of encoding characters according to the order of strokes
(a) Get a letter directly. For example,
corresponds to the letter "B"
corresponds to the letter "R"
corresponds to the letter "E"
(b) Horizontal first, and then vertical. For example,
is constructed with " " corresponding to the letters "IX"
(c) Left-slanting first, and then right-slanting. For example,
is constructed with " " corresponding to the letters "JL"
(d) From left to right. For example,
is constructed with " " corresponding to the letters "RR"
(e) From left to middle and then right. For example,
is construceted with " " corresponding to the letters "FTCJ"
(f) From top left, top middle, top right to bottom left, bottom middle, bottom right. For example,
the top of is constructed with " " corresponding to the letters "VVV"
the bottom of is constructed with " " corresponding to the letters "JEJ"
(g) From top to bottom. For example,
is constructed with " " corresponding to the letters "ES"
(h) From top to middle, and then bottom. For example,
is constructed with " " corresponding to the letters "XIO"
is constructed with " " corresponding to the letters "YXO"
(i) From left top, left middle, left bottom to right top, right middle, right bottom. For example,
the left of is constructed with " " corresponding to the letters "IXJ"
the right of is constructed with " " corresponding to the letters "RUR"
(j) From outside to inside. For example,
is constructed with " " corresponding to the letters "CX"
is constructed with " " corresponding to the letters "UU"
(k) From outside to inside, and then seal. For example,
is constructed with " " corresponding to the letters "UIII"
is constructed with " " corresponding to the letters "UOI"
(l) From left top to right bottom. For example.
is constructed with " " corresponding to the letters "PJL"
is constructed with " " corresponding to the letters "RA"
(m) From right top to left bottom. For example,
is constructed with " " corresponding to the letters "KZVJJ"
is constructed with " " corresponding to the letters "DL"
(n) From middle to both sides. For example,
is constructed with " " corresponding to the letters "AJ"
While decomposing characters in accordance with the order of strokes, the user should take the letter constructed with as many strokes as possible at each step. For instance, " " should be decomposed into " " corresponding to "AXK", but not " " corresponding to "VIXK", or " " corresponding to "VIXVI".
3. Examples of the correspondence relationship between 42 states of letters in different directions and the keys on the standard keyboard
The correspondence relationship is illustrated in FIG. 5 and given in Table-1, inwhich
letters in [ ] are in east direction, corresponding to 26 letter keys on the keyboard respectively;
those in () are the variable forms of the letters in all direction ##SPC1##
In the following description, a "step" means an angle of 90 degrees.
(a) Letters in east direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________Chinese character keys on the keyboard______________________________________ get a letter directly X get a letter directly O get a letter directly AO______________________________________
Note: These characters and the corresponding letters are in the regular directions. The user can enter the keys directly without spinning the corresponding letters. The characters themselves are in east direction as shown respectively in FIGS. 1(x), 1(o) and 1(a).
(b) Letters in south direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ counterclockwise spun by H 1 step counterclockwise spun by I 1 step counterclockwise V spun by 1 step counterclockwise U spun by 1 step______________________________________
Note: The letters represented by bold lines in the characters can be counter clockwise spun by 1 step to correspond to the keys in east direction. The bold parts in the characters are the letters in south direction referring respectively to FIGS. 1(h), 1(i), 1(m), 1(v) and 1(u).
(c) Letters in west direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ clockwise spun by K 2 steps clockwise spun by E 2 steps clockwise spun by L 2 steps______________________________________
Note: The letters represented by bold lines in the characters can be clockwise spun by 2 steps to correspond to the keys in east direction. The bold parts in the characters are the letters in west direction as shown respectively in FIGS. 1(k), 1(e) and 1(l).
(d) Letters in north direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ clockwise spun E by 1 step______________________________________
Note: The letters represented by bold lines in the characters can be clockwise spun by 1 steps to correspond to the keys in east direction. The bold parts in the characters are the letters in north direction as shown in FIG. 1(e).
(e) Letters in southeast direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ counterclockwise spun by A a half step______________________________________
Note: The letters represented by bold lines in the characters can be counterclockwise spun by a half step to correspond to the keys in east direction. The bold parts in the characters are the letters in southeast direction as shown in FIG. 1(a).
(f) Letters in southwest direction and the characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ counterclockwise spun by J 1 and a half steps counterclockwise spun by E 1 and a half steps______________________________________
Note: The letters represented by bold lines in the characters can be counterclockwise spun by one and a half steps to correspond to the keys in east direction. The bold parts in the characters are the letters in southwest direction as shown respectively in FIGS. 1(j) and 1(e).
(g) Letters in northwest direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ counterclockwise spun by T 2 and a half steps counterclockwise spun by F 2 and a half steps______________________________________
Note: The letters represented by bold lines in the characters can be counterclockwise spun by two and a half steps to correspond to the keys in east direction. The bold parts in the characters are the letters in northwest direction as shown respectively in FIGS. 1(t) and 3(a).
(h) Letters in northeast direction and characters which can be spun to correspond to the keys on the keyboard
______________________________________ Keys onChinese character Steps of spinning the keyboard______________________________________ counterclockwise spun by K 3 and a half steps counterclockwise spun by K 3 and a half steps______________________________________
Note: The letters represented by bold lines in the characters can be counterclockwise spun by three and a half steps to correspond to the keys in east direction. The bold parts in the characters are the letters in northeast direction as shown in FIG. 1(k).
4. Six direction patterns formed by directions of letters which are got by taking Chinese characters apart in accordance with the order of strokes
(a) Characters of east direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ R east XU east______________________________________
Note: Each of the above characters is a single character, corresponding to either a letter in east direction, or two letters in east direction that composing the character as shown in FIGS. 1(r), 1(x) and 1(u).
(b) Characters of south direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ H south III south______________________________________
Note: Each of the above characters is a single character, corresponding to either a letter in south direction, or several letters in south direction that composing the character.
(c) Characters of west direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ E west______________________________________
Note: The above character is a single one, corresponding to a letter in west direction.
(d) Characters of north direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ E north______________________________________
Note: The above character is a single one, corresponding to a letter in north direction.
(e) Characters of mixed direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ EFX mixed______________________________________
Note: Those characters composed of letters in different directions are called characters of mixed direction pattern. For example, , being a character of mixed direction pattern, is composed of corresponding to "E" in north direction, F corresponding to "F" in east direction, and corresponding to "X" in southeast direction.
(f) Characters of changed and mixed direction pattern
______________________________________Chinese character Keys on the keyboard Direction pattern______________________________________ FH changed and mixed______________________________________
Note: Those characters consisting of not only letters (positive letters), but also inverted letters in different directions are called characters of changed and mixed direction pattern. For example, , being a character of changed and mixed direction pattern, is composed of corresponding to inverted "F" in northwest direction, and corresponding to "H" in south direction.
5. Detailed examples of inputting characters using letters of English alphabet
(a) Encoding single character and inputting method thereof
(a1) Characters composed of a single letter
Press the key on the keyboard that corresponds to the letter, and then press space bar to end entering. For example
--press E key and space bar
--press B key and space bar
--press Y key and space bar
--press I key and space bar
Note: Bemuse of the great discrete degree which is 26*26=676, there is no duplicate cede after entering three keys.
(a2) Characters composed of 2 letters
Press each of the keys on the keyboard that correspond to the 2 letters once, and then press space bar once to end entering. For example,
--press F, J keys and space bar
--press O, X keys and space bar
--press A, T keys and space bar
--press A, O keys and space bar
Note: The discrete degree of the characters composed of 2 letters is 26*26*26=17576. Due to the above discrete degree, there is no duplicate code at all after entering four letters.
(a3) Characters composed of 3 letters
Press each of the keys on the keyboard that correspond to the 3 letters once, and then press space bar once to end entering. For example,
--press A, X, I keys and space bar
--press B, B, B keys and space bar
--press O, O, O keys and space bar
--press A, X, K keys and space bar
Note: The discrete degree of the characters composed of 3 letters is 26*26*26*26=456976. Because the discrete degree is so great, all of the Chinese characters in Chinese Character Set can be encoded. Besides, more than 450 thousand phrases can be encoded.
(a4) Characters composed of 4 letters
Press each of the keys on the keyboard that correspond to the 4 letters one by one. For example,
--press X, J, X, V keys
--press Y, X, J, I keys
--press J, X, O, L keys
--press F, J, L, X keys
Note: The discrete degree of the characters composed of 4 letters is also 456976. There is no duplicate code at all after entering five letters.
(a5) Characters composed of 5 or more letters
Press each of the keys on the keyboard that correspond to the first 3 and the last 1 letters once.
For characters consisting of two characters respectively on the left and on the right:
Select the start and end letters of the left character, as well as the start and end letters of the right character, and then press the keys on the keyboard that correspond to the selected letters. For example,
--press X, X, X, T keys
--press J, K, I, Y keys
Note: The start and end letters are marked with solid lines.
For characters consisting of two characters respectively on the top and on the bottom:
Select the start and end letters of the top character, as well as the start and end letters of the bottom character, and then press the keys on the keyboard that correspond to the selected letters. For example,
--press F, J, K, I keys
--press H, X, J, J keys
Note: The start and end letters are marked with solid fines.
For characters consisting of two characters respectively inside and outside:
Select the start and end letters of the outside character, as well as the start and end letters of inside character, and then press the keys on the keyboard that correspond to the selected letter. For example
--press I, C, I, F keys
--press I, C, K, I keys
Note: The start and end letters are marked with solid lines.
In the above three cases, if one of the two characters contained in the character encoded is formed with a single letter, press the first 3 and the last 1 letters of the character. And if the character has less than 4 letters, press space bar to end entering. For example,
Characters composed of two characters on the left and on the right:
--press O, X, I, O keys
--press X, C, J, F keys
Characters composed of two characters on the top and on the bottom:
--press E, A, B, J keys
--press I, X, R, J keys
The above rule is based upon the constructual features of Chinese characters. Thus, it is advantageous to reduce duplicate codes.
(b) Encoding phrases and inputting method thereof
(b1) Phrases consisting of two characters
(b11) Two-character phrases composed of two letters:
Press each of the key on the keyboard that correspond to the first and the second letters, and then press space bar to end entering. For example,
--press H, V keys and space bar
--press T, I keys and space bar
(b12) Two-character phrases composed of three letters:
Press the keys on the keyboard that correspond to the three letters, and then press space bar. For example,
--press E, E, B keys and space bar
--press E, C, X keys and space bar
(b13) Two-character phrases composed of four letters:
Press the keys on the keyboard that correspond to the four letters. For example,
--press Y, J, Y, R keys
--press Y, K, H, F keys
(b14) Two-character phrases composed of five or more letters:
If any one of the two characters of said phrase is composed of a single letter, select the first 3 and the last 1 letters, and press the keys on the keyboard that correspond to the selected letters one by one. For example,
--press B, F, J, B keys
--press B, K, E, Y keys
If both of the two characters consist of two or more letters, select the start and the end letters of the first character, and the start and the end letters of the second character, and press the keys on the keyboard that correspond to the selected letters one by one. For example,
--press K, R, A, K keys
--press T, H, H, S keys
(b2) Phrases consisting of three characters
Press each of the keys on the keyboard that correspond to the start letters of the three characters, and then if the last character consists of a single letter, press space bar once to end entering, otherwise press the key on the keyboard that corresponds to the end letter of the last character. For examples,
--press I, Y, T, X keys
--press O, U, R keys and space bar
(b3) Phrases consisting of four characters
Press each of the keys on the keyboard that correspond to the start letters of the four characters one by one. For example,
--press Y, O, W, F keys
--press F, V, X, I keys
(b4) Phrases consisting of five or more characters
Select the start letters of the first 3 and the last 1 characters, and then press each of the keys on the keyboard that correspond to the selected letters. For example
--press J, U, H, A keys
--press R, I, K, U keys
--press O, K, R, U keys
--press R, R, K, T keys
The present invention is not limited to the particular embodiments described above. Various changes and modifications may be made without departing the scope of the appended claims.
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The present invention relates to the direction code for encoding Chinese characters using English alphabet and the inputting method thereof. While encoding a Chinese character, constructing the English letters that exist in said character according to horizontal stroke " ", vertical stroke " ", left-slanting stroke " " and right-slanting stroke " " of Chinese characters, decomposing said character into a combination of certain actual postures among 161 ones of the letters according to order of strokes and rules of the order of strokes, said combination of postures being limited to 6 direction patterns, said letters being in 8 positive directions and 8 inverted directions presented by the letters respectively, said combination of the letters being the direction code of said Chinese character.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to manual dollys. More specifically, the present invention relates to an aircraft dolly having particular utility for the manipulation of tail wheeled aircraft.
2. Description of the Related Art
There are known several manual dolly configurations suitable for general purpose use.
U.S. Pat. No. 4,505,489 to Specie discloses a dolly system for campgrounds and having particular utility for the moving of picnic tables and the like. An elongated handle member is journaled to each separate axle of a pair of spaced apart wheels. An elongated lifting member connected to the elongated handle extends forwardly of the wheels and contains a U-channeled brace thereon for fitting under the cross brace of a picnic table. The operator pushes down on the dolly in the conventional manner to lift the object to be moved and steers the dolly from a cross-bar linking two parallel spaced apart elongated handle members.
U.S. Pat. No. 3,799,582 to Courtright discloses a wheel cradle structure for use with agricultural irrigation lines. The Courtright reference is not a levered dolly system but shows a cradle capable of suspending a wheel off of the ground. The cradle is axially suspended between two wheels and may be connected in series with like cradles through linkage arms contained on either side of the cradle. The operative wheel support members of Courtright extend at right angles to the axles of the cradle wheels.
U.S. Pat. No. 3,456,960 to Rector discloses a two-wheeled hand cart having carrying tines which fold up against the hand cart frame. Lift for the object to be carried is supplied in the conventional manner by pushing down on the elongated handle members of the hand cart. The carrying tines of the Rector invention extend at right angles to the wheel axle.
U.S. Pat. No. 3,306,624 to Goss discloses a dolly for moving boxes of glass. The Goss invention discloses a carrying base which is tipped forwardly to fit under a lower edge of a glass piece and then force is applied downwardly on the handle to bring the glass sheet to the horizontal. The glass sheet is balanced between two elongated handle members serving as levers for the carrying base.
U.S. Pat. No. 1,241,418 to Mosher discloses a collapsible automobile dolly. Mosher discloses two roller wheels supported by a central axle. Disclosed on the central axle are support members for holding an automobile axle or axles off the ground. An elongated tilt bar extends from the central axle.
None of the above inventions disclose any utility for moving a wheeled craft such as a tail wheel airplane by surrounding a wheel thereof with lifting arms extending parallel to the axle from an elongated lever. Further, the disclosed dolly systems all rely on a downward force placed on the lever to lift the object to be moved thus placing strain on the back and shoulders and making steering of the object more difficult.
Also, in using a downward force, the operator's body weight is counterbalanced by the object lifted, thus tending to lift the operator, resulting in less traction between the operator and the ground. Such a traction loss can be inconvenient or even dangerous on loose surfaces, such as gravel, when the operator is "manually" operating a dolly.
There are known prior aircraft dollys operating in a manner similar to the known dollys, which require the operator to physically lift the aircraft onto the carrying platform of dolly. As there are often no convenient lift points or pushing surfaces located on an aircraft there exists the need to provide for a lifting dolly which can be placed around the aircraft wheel without manipulation of the aircraft itself, and thereby lift the wheel providing in effect a wheeled handle for manipulation of the aircraft by pushing or pulling. It is further desirable to provide such an aircraft dolly which derives its lifting force from a lifting of the lever as can be done with the strong leg muscles of the operator, as in proper lifting technique, thereby preventing body strain on the operator and making the aircraft easier to steer during manipulation thereof. The present invention provides a dolly system having these advantages and which is further capable of being easily stored. A dolly according to the present invention is constructed so as to minimize the possibility of the aircraft loosening itself from the constraints of the dolly.
There is also known a tail wheel aircraft tow bar. U.S. Pat. No. 4,659,124 discloses a hand carried tow bar for tailwheel aircraft having an elongated bar with clamping jaws at an end thereof. The jaws are clamped around a tail spring of the aircraft and the operator manipulates the aircraft by pulling, or less effectively, pushing, on a handle located at a second end of the bar. The tail spring of the aircraft must having a strongly vertical orientation and generous clearance beneath the aircraft tail for this tow bar to be effective. The clamping force of the jaws and subsequent manipulation of the aircraft through the tailspring might tend to cause premature metal fatigue in the tailspring. Turning of the aircraft using this tow bar requires great effort against the tail spring to force the craft against normal wheel friction instead of using the wheels to pivot the craft. The design of this tow bar also requires relatively elaborate machining and/or casting of its component parts. Use of this tow bar presents the possibility of injurious contact to the aircraft from the tow bar. Further, an individual tow bar of this type is not readily adaptable for use with a wide range of tail spring sizes.
Obviously then there exists a need for a tail wheel aircraft manipulator mechanism which eliminates these drawbacks in the current art. The present invention not only solves the aforementioned problems of the current art but is also readily adaptable for use with nose wheel aircraft.
SUMMARY OF THE INVENTION
An aircraft dolly is disclosed which generally comprises:
(a) an axle,
(b) a wheel rotatably attached to the axle,
(c) an elongated lever attached to the axle, the elongated lever extending rearwardly from the axle, and
(d) a wheel-holding assembly attached to the lever and having spaced apart arms extending from the lever and substantially parallel to the axle, wherein the arms receive a wheel therebetween.
A particularly advantageous feature of the present invention is an axle mounted lever carrying thereon an aircraft wheel-holding assembly capable of being placed about an aircraft wheel without manipulation of the aircraft. The lever is attached to the axle at some point along the length of the lever. The lever may extend forwardly of the axle in certain applications, e.g., a motorized dolly, should it be found desirable to locate the wheel holding assembly forwardly of the axle. The lever will, of course, still extend rearwardly from the axle to provide the operator with a necessary location on the device for manipulating the aircraft.
For manual operation, the lever preferably has a first section extending steeply downward from the axle and an elongated second section extending rearwardly therefrom. The wheel-holding assembly will preferably be located proximal to the juncture of the first and second sections and have a void between the spaced apart arms so that the arms may be fitted about the lower portion of the tail wheel of the aircraft. The elongated lever then merely has to be lifted to raise the tail wheel of the aircraft off the ground, thus supporting the aircraft on the dolly. The aircraft may then be rolled on dolly wheels by pushing or pulling on the handle.
A rotating sleeve may be provided on the rear wheel-holding assembly arm in order that the tail wheel may rotate thereon during a sharp push or pull on the lever thereby preventing the tail wheel of the aircraft from leaving the wheel holding assembly. Should the wheel-holding assembly be located forwardly of the axle, a rotating sleeve may be supplied on the forward wheel-holding arm to prevent errant movement of the tail wheel. Alternatively, the aircraft wheel may be lashed to the dolly to prevent wheel movement.
The first end of the lever is preferably attached to the axle off of the longitudinal center of the axle. This location will place the midline of the wheel-holding assembly, as it extends from the lever, substantially in line with the center of the axle thereby providing good control for the manipulation of the aircraft.
Provision is conveniently made for adjusting the distance between the spaced apart arms of the wheel-holding assembly in order to accommodate various sized tail wheels as would be found on different makes of aircraft.
A handle which has both horizontal and vertical members, ordinarily is attached to the second end of the lever. The vertical members extend upwardly to make the lever easily manipulatable as the lever is generally operated close to the ground when placing the dolly under the aircraft. Horizontal members are also provided for ease of lifting and manipulation of the aircraft. A trailer hitch attachment may also be used separately or in conjunction with the manual handle should the operator desire to attach the dolly to a separate motive force such as a lawn tractor.
Other attendant advantages will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a device according to the present invention shown in environment operating on the tail wheel of an aircraft;
FIG. 2 is a top plan view of a device according to the present invention; and
FIG. 3 is a side view of a device according to the present invention taken along line 3--3 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIG. 1, a dolly 10 especially suitable for the manipulation of a tail wheel aircraft 12 is fittable beneath the tail wheel 14 of an aircraft for the lifting of the aircraft 12 so that the dolly 10 supports the aircraft 12 for manipulation thereof by the dolly 10.
The dolly 10 of the present invention will be described in its quiescent state, i.e., detached from the aircraft 12 and resting upon the ground in a position ordinarily ready for use. Positional words such as up, down, right, left, front, rear, etc. will be used in their ordinary sense as derived from an operator standing behind the dolly 10 at a handle thereof with the wheel and axle being at the front, or forward end of the dolly, as seen in FIG. 1.
As seen in FIG. 2, the dolly generally comprises an axle and wheel assembly 16, a lever 18, and a wheel-holding assembly 20.
At the forward end of the dolly is an axle 22 to which is rotatably mounted a first wheel 24 and a second wheel 26.
Attached to the axle 22 at a point off center between the two wheels 24, 26 is a lever, indicated generally at 18. The lever 18 is located off center of the axle 22 so as to place the wheel-holding assembly 20 generally over the midline of the axle 22 between the two wheels 24, 26. This will generally stabilize the load and make the dolly 10 easier to manipulate when under load.
As seen in FIG. 3, the lever 18 of the preferred embodiment comprises a first section 28 attached to the axle by welding or the like and extending at a steep angle towards the ground for a length approximately the radius of the wheels 24, 26. Extending rearwardly from the first lever section 28 is a second lever section 30. The second lever section 30 travels rearwardly at a slight angle to the ground until meeting the ground. A third lever section 31 then angles upwardly therefrom at a slight angle to the ground while traveling rearwardly for such a distance as to establish reasonable leverage for the dolly 10 as further explained below. A throughhole 34 is bored transverse to the longitudinal axis of the lever 18 in the lever second section 30 forward of a pivot point 32, for reasons explained below.
Alternatively, the lever 18 could, of course, extend rearwardly with only one bend at the pivot point 32, or entirely without bends. The nonbent lever arrangement would, of course, necessitate structural modification of the wheel holding assembly 20 to keep the placement of the wheel holding area of the wheel-holding assembly as close to the ground as possible. Further, it is envisioned that lever 18 may extend forwardly of the axle 22 where forward placement of the wheel-holding assembly 20 is desired; such as may be the case for a powered dolly or with certain makes of aircraft.
As seen in FIG. 2, at a second, or rearward, lever end 36 is attached a V-shaped handle 38 extending rearwardly from the second lever end 36 having first and second horizontal handle members, 40 and 42 respectively as seen in FIG. 1. Extending upwardly from the respective horizontal handle members 40, 42 are first and second vertical handle members, 44 and 46 respectively. The vertical handle member 44, 46 provide for ease of manipulation of the dolly 10 near the ground to lessen the backbending or stooping of the operator when positioning the dolly for use as further explained below. The horizontal handle members 40, 42 provide readily graspable lifting and steering surfaces when the dolly is in use.
A yoke 48 is pivotally attached at a point approximately midway along the length of the second lever section 30 by a yoke pivot pin 50. The yoke 48 extends rearwardly along the third lever section 31 to end between V-shaped horizontal handle members 44, 46 at a hitch 52. Yoke 48 may be constructed from a U-channel bracket, or from parallel arms extending on either side of the third lever section 31. The yoke 48 is secured about the lever 18 in convenient position by placing a pin 54 through holes 56 and 58 respectively, drilled transversely in both the yoke and third handle section. Hitch 52 will then be located unobtrusively between the horizontal members of the handle 42.
As seen in FIG. 3, the yoke 48 and attached hitch 52 may be angled downwardly from the lever third section 31 by releasing a perforated yoke support 60 which is an armature having a series of holes therethrough. The yoke support 60 is pivotally connected at a first end thereof to yoke 48 by a yoke support pivot 62. The yoke 48 is fastened at a second end thereof to the lever 18 by the pin 54 through a yoke support throughhole 64 in lever 18. The yoke 48 and the hitch 52 may be placed lower than the handle 38 for additional lift of the lever 18 when attaching the lever to a tractor vehicle through the hitch 52. Although illustrated as a ball hitch, hitch 52 may comprise various types of hitch arrangements. The perforated yoke support 60, yoke pivot pin 50 and associated pins and throughholes together provide a means for securing the yoke 48 at an angle to the lever 18.
As seen in FIGS. 2 and 3, the wheel-holding assembly 20 comprises a first arm 66 and second arm 68 extending laterally from lever 18 towards the midline of the axle 22. The first arm 66 and the second arm 68 are "L"-shaped members having the short legs of the "L's" pointed towards each other to form a substantially open rectangular wheel-holding assembly 20. The wheel holding assembly 20 may thus be placed about the tail wheel 14 without manipulation thereof.
The first arm 66 is affixed to the lever 18 at the junction of the first lever section 28 and second lever section 30. The second arm 68 is selectively located in the throughhole 34 located along the forward section of second lever section 30, dependant upon the size of the tail wheel 14 to be secured, thus making the dolly 10 easily adaptable to a wide range of aircraft.
As an alternative to the throughhole 34, which is a transverse channel formed through lever 18, a series of fixed throughholes may be provided for a variable adjustment of the second arm 68. The second arm 68 is fastened to the lever 18 by placing a threaded end 70 of the second arm 68 through the throughhole 34 of the lever 18 and securing the second arm therein by means of a bolt 72.
The first arm 66, being located at the juncture of the first and second lever sections, 28 and 30 respectively, is therefore placed higher on the lever 18 than the second arm 68. The first arm 66 also extends farther towards the midline of the axle than does second arm 68. These two features aid in the positioning of the wheel-holding assembly 20 around the tail wheel 14 when manipulating the dolly 10 into an operative position.
A sleeve 74 is fitted loosely over second arm 68 so as to be rotatable thereon. The sleeve 74 will provide a rolling surface for the tail wheel 14 in order to prevent the tail wheel 14 from escaping the wheel-holding assembly 20 should a sharp forward push be given to the dolly 10 when transporting the aircraft 12. The first arm 66 can also be fitted with a rolling sleeve especially in those embodiments where the wheel-holding assembly 20 is carried forward of the axle 22. In the preferred embodiment the first arm 66 is located less than the diameter of a wheel away from the axle 22 thereby allowing the axle 22 to act as a forward stop to the tail wheel 14 should a sharp pull on the dolly 10 dislodge the tail wheel 14 from the wheel-holding assembly 20.
In use, the dolly is rolled diagonally forward of the tail wheel 14 thus avoiding possible contact with the sensitive aircraft tail mechanism. The wheel-holding assembly 20 is then pulled towards the tail wheel 14 to a position where first arm 66 is approximately in front of the tail wheel 14. The lever 18 is then pivoted on the pivot point 32 to lift the wheels 24, 26 off the ground while pivoting wheeling-holding assembly 20 under and around the tail wheel 14. Once the wheel-holding assembly 20 is in proper position around the tail wheel, the operator simply lifts upwardly on the lever 18 at the handle 38. The leverage of the handle will easily lift the tail wheel 14 and aircraft 12 off of the ground whereby the aircraft may then be rolled on dolly wheels 24 and 26 and steered by handle 38. Because the aircraft tail is supported on the spaced apart wheels, pivoting of the tail is easily accomplished. Also, because the tail wheel 14 is the only component of the aircraft 12 to be touched by the dolly 10, the possibility of damage to the aircraft from contact with dolly is substantially decreased.
Should the operator wish to use a tractor device to tow the aircraft, the wheel-holding assembly is positioned around the tail wheel as per above. Then the yoke 48 is detached from lever 18 by removal of the pin 54. Hitch 52 is then attached to a tractor hitch assembly (not shown) and the proper angle is selected between yoke 48 and lever 18 and the yoke secured at that angle by pinning the perforated yoke support 60 in place through the yoke support throughhole 64 in lever 18.
The current invention thus provides a simple and efficient means for manipulating tail wheel aircraft with minimal strain to a manual operator. It will be realized that the present invention may be equally applicable to the manipulation of nose wheel aircraft, especially those not having aerodynamic skirts located around the nose wheel.
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A dolly particularly suitable for manipulation of tail wheel aircraft is disclosed as having a wheel and axle assembly with an elongated lever extending rearwardly from the axle. A wheel-holding assembly comprised of two arms forming an open rectangle extends from the lever. The wheel-holding assembly is fitted around the tail wheel of an aircraft without manipulation of the aircraft. A handle member is supplied at the end of the elongated lever to aid in manipulation and in lifting of the lever to remove the tail wheel of the aircraft from the ground so that the plane may be manipulated through the dolly. The dolly is also provided with a hitch assembly for use with tractor vehicles.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. application Ser. No. 10/838,157, filed Apr. 30, 2004, and from U.S. application Ser. No. 10/600,854 filed Jun. 20, 2003, both entitled “Salinosporamides and Methods for Use Thereof.”
GRANT INFORMATION
[0002] This invention was made in part with government support under Grant No. CA44848 awarded by the National Institutes of Health, National Cancer Institute. The United States government may have certain rights in this invention.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] The invention relates generally to anti-neoplastic agents, and more particularly to salinosporamides and their use as anti-neoplastic agents.
BACKGROUND INFORMATION
[0004] Neoplastic diseases, characterized by the proliferation of cells not subject to the normal control of cell growth, are a major cause of death in humans. Clinical experience in chemotherapy has demonstrated that new and more effective cytotoxic drugs are desirable to treat these diseases. Indeed, the use of anti-neoplastic agents has increased due to the identification of new neoplasms and cancer cell types with metastases to different areas, and due to the effectiveness of antineoplastic treatment protocols as a primary and adjunctive medical treatment for cancer.
[0005] Since anti-neoplastic agents are cytotoxic (poisonous to cells) they not only interfere with the growth of tumor cells, but those of normal cells. Anti-neoplastic agents have more of an effect on tumor cells than normal cells because of their rapid growth. Thus, normal tissue cells that are affected by anti-neoplastic agents are rapidly dividing cells, such as bone marrow (seen in low blood counts), hair follicles (seen by way of hair loss) and the GI mucosal epithelium (accounting for nausea, vomiting, loss of appetite, diarrhea). In general, anti-neoplastic agents have the lowest therapeutic indices of any class of drugs used in humans and hence produce significant and potentially life-threatening toxicities. Certain commonly-used anti-neoplastic agents have unique and acute toxicities for specific tissues. For example, the vinca alkaloids possess significant toxicity for nervous tissues, while adriamycin has specific toxicity for heart tissue and bleomycin has for lung tissue.
[0006] Thus, there is a continuing need for anti-neoplastic agents that are effective in inhibiting the proliferation of hyperproliferative cells while also exhibiting IC 50 values lower than those values found for current anti-neoplastic agents, thereby resulting in marked decrease in potentially serious side effects.
SUMMARY OF THE INVENTION
[0007] The present invention is based on the discovery that certain fermentation products of the marine actinomycete strains CNB392 and CNB476 are effective inhibitors of hyperproliferative mammalian cells. The CNB392 and CNB476 strains lie within the family Micromonosporaceae, and the generic epithet Salinospora has been proposed for this obligate marine group. The reaction products produced by this strain are classified as salinosporamides, and are particularly advantageous in treating neoplastic disorders due to their low molecular weight, low IC 50 values, high pharmaceutical potency, and selectivity for cancer cells over fungi.
[0008] In one embodiment of the invention, there is provided compounds having the structure (I):
[0000]
[0000] wherein:
[0009] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl;
[0010] Each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl;
[0011] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl; and
[0012] x is 0 to 8.
[0013] In a further embodiment of the invention, there are provided compounds having the structure (II):
[0000]
[0000] wherein:
[0014] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl;
[0015] Each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl;
[0016] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl; and
[0017] x is 0 to 8.
[0018] In another embodiment of the invention, there are provided compounds having the structure (III):
[0000]
[0000] wherein:
[0019] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl,
[0020] each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl,
[0021] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl, and
[0022] x is 0 to 8.
[0023] In still a further embodiment of the invention, there are provided compounds having the structure (IV):
[0000]
[0024] In a further embodiment of the invention, there are provided compounds having the structure (V):
[0000]
[0025] In a further embodiment of the invention, there are provided compounds having the structure (VI):
[0000]
[0026] In another embodiment, there are provided pharmaceutical compositions including at least one compound of structures I-VI in a pharmaceutically acceptable carrier therefor.
[0027] In another embodiment, there are provided articles of manufacture including packaging material and a pharmaceutical composition contained within the packaging material, wherein the packaging material includes a label which indicates that the pharmaceutical composition can be used for treatment of cell proliferative disorders and wherein the pharmaceutical composition includes at least one compound of structures I-VI.
[0028] In yet another embodiment, there are provided methods for treating a mammalian cell proliferative disorder. Such a method can be performed for example, by administering to a subject in need thereof a therapeutically effective amount of a compound having structures I-VI.
[0029] In an additional embodiment, there are provided methods for producing a compound of structures I-VI having the ability to inhibit the proliferation of hyperproliferative mammalian cells. Such a method can be performed, for example, by cultivating a culture of a Salinospora sp. strains CNB392 (ATCC #______) or CNB476 (ATCC PTA-5275) and isolating from the culture at least one compound of structure I.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 depicts the chemical structure of an exemplary compound of the invention, Salinosporamide A, with relative stereochemistry.
[0031] FIG. 2 depicts a phylogenetic tree illustrating the phylogeny of “ Salinospora”.
[0032] FIG. 3 depicts the chemical structure of Etoposide, an anti-neoplastic agent in therapy against several human cancers.
[0033] FIG. 4 compares the cytotoxic activity and dose response curves of Salinosporamide A and Etoposide.
[0034] FIG. 5 is a block diagram depicting an exemplary separation scheme used to isolate Salinosporamide A.
[0035] FIGS. 6-14 set forth NMR, IR, and UV spectroscopic data used to elucidate the structure of Salinosporamide A.
[0036] FIG. 15 sets forth the signature nucleotides that strains CNB392 and CNB476 possess within their 16S rDNA, which separate these strains phylogenetically from all other family members of the family Micromonosporaceae.
[0037] FIG. 16 depicts the chemical structure of an exemplary compound of the invention, salinosporamide A (structure V), with absolute stereochemistry.
[0038] FIG. 17 ORTEP plot of the final X-ray structure of salinosporamide A, depicting the absolute stereochemistry.
DETAILED DESCRIPTION OF THE INVENTION
[0039] In one embodiment, there are provided compounds having the structure (I):
[0000]
[0000] wherein:
[0040] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl;
[0041] Each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl;
[0042] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl; and
[0043] x is 0 to 8.
[0044] In a further embodiment of the invention, there are provided compounds having the structure (II):
[0000]
[0000] wherein:
[0045] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl;
[0046] Each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl;
[0047] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl; and
[0048] x is 0 to 8.
[0049] In one embodiment, there are provided compounds having the structure (III):
[0000]
[0000] wherein:
[0050] R 1 to R 3 are each independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, thioalkyl, substituted thioalkyl, hydroxy, halogen, amino, amido, carboxyl, —C(O)H, acyl, oxyacyl, carbamate, sulfonyl, sulfonamide, or sulfuryl,
[0051] each R 4 is independently alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl,
[0052] E 1 to E 4 are each independently —O, —NR 5 , or —S, wherein R 5 is —H or C 1 -C 6 alkyl, and
[0053] x is 0 to 8.
[0054] In still a further embodiment of the invention, there are provided compounds having the structure (IV):
[0000]
[0055] In a further embodiment of the invention, there are provided compounds having the structure (V):
[0000]
[0056] In a further embodiment of the invention, there are provided compounds having the structure (VI):
[0000]
[0057] As used herein, the term “alkyl” refers to a monovalent straight or branched chain hydrocarbon group having from one to about 12 carbon atoms, including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, and the like.
[0058] As used herein, “substituted alkyl” refers to alkyl groups further bearing one or more substituents selected from hydroxy, alkoxy, mercapto, cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, aryloxy, substituted aryloxy, halogen, cyano, nitro, amino, amido, —C(O)H, acyl, oxyacyl, carboxyl, sulfonyl, sulfonamide, sulfuryl, and the like.
[0059] As used herein, “lower alkyl” refers to alkyl groups having from 1 to about 6 carbon atoms.
[0060] As used herein, “alkenyl” refers to straight or branched chain hydrocarbyl groups having one or more carbon-carbon double bonds, and having in the range of about 2 up to 12 carbon atoms, and “substituted alkenyl” refers to alkenyl groups further bearing one or more substituents as set forth above.
[0061] As used herein, “alkynyl” refers to straight or branched chain hydrocarbyl groups having at least one carbon-carbon triple bond, and having in the range of about 2 up to 12 carbon atoms, and “substituted alkynyl” refers to alkynyl groups further bearing one or more substituents as set forth above.
[0062] As used herein, “aryl” refers to aromatic groups having in the range of 6 up to 14 carbon atoms and “substituted aryl” refers to aryl groups further bearing one or more substituents as set forth above.
[0063] As used herein, “heteroaryl” refers to aromatic rings containing one or more heteroatoms (e.g., N, O, S, or the like) as part of the ring structure, and having in the range of 3 up to 14 carbon atoms and “substituted heteroaryl” refers to heteroaryl groups further bearing one or more substituents as set forth above.
[0064] As used herein, “alkoxy” refers to the moiety —O-alkyl-, wherein alkyl is as defined above, and “substituted alkoxy” refers to alkoxyl groups further bearing one or more substituents as set forth above.
[0065] As used herein, “thioalkyl” refers to the moiety —S-alkyl-, wherein alkyl is as defined above, and “substituted thioalkyl” refers to thioalkyl groups further bearing one or more substituents as set forth above.
[0066] As used herein, “cycloalkyl” refers to ring-containing alkyl groups containing in the range of about 3 up to 8 carbon atoms, and “substituted cycloalkyl” refers to cycloalkyl groups further bearing one or more substituents as set forth above.
[0067] As used herein, “heterocyclic”, refers to cyclic (i.e., ring-containing) groups containing one or more heteroatoms (e.g., N, O, S, or the like) as part of the ring structure, and having in the range of 3 up to 14 carbon atoms and “substituted heterocyclic” refers to heterocyclic groups further bearing one or more substituents as set forth above.
[0068] In certain embodiments, there are provided compounds of structures I-III wherein E 1 , E 3 , and E 4 are —O, and E 2 is —NH.
[0069] In certain embodiments, there are provided compounds of structures 1-r wherein R 1 and R 2 are —H, alkyl, or substituted alkyl, and R 3 is hydroxy or alkoxy. In some embodiments, R 1 is substituted alkyl. Exemplary substituted alkyls contemplated for use include halogenated alkyls, such as for example chlorinated alkyls.
[0070] The compounds of the invention may be formulated into pharmaceutical compositions as natural or salt forms. Pharmaceutically acceptable non-toxic salts include the base addition salts (formed with free carboxyl or other anionic groups) which may be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino-ethanol, histidine, procaine, and the like. Such salts may also be formed as acid addition salts with any free cationic groups and will generally be formed with inorganic acids such as, for example, hydrochloric, sulfuric, or phosphoric acids, or organic acids such as acetic, p-toluenesulfonic, methanesulfonic acid, oxalic, tartaric, mandelic, and the like. Salts of the invention include amine salts formed by the protonation of an amino group with inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid, and the like. Salts of the invention also include amine salts formed by the protonation of an amino group with suitable organic acids, such as p-toluenesulfonic acid, acetic acid, and the like. Additional excipients which are contemplated for use in the practice of the present invention are those available to those of ordinary skill in the art, for example, those found in the United States Pharmacopeia Vol. XXII and National Formulary Vol. XVII, U.S. Pharmacopeia Convention, Inc., Rockville, Md. (1989), the relevant contents of which is incorporated herein by reference.
[0071] The compounds according to this invention may contain one or more asymmetric carbon atoms and thus occur as racemates and racemic mixtures, single enantiomers, diastereomeric mixtures and individual diastereomers. The term “stereoisomer” refers to chemical compounds which differ from each other only in the way that the different groups in the molecules are oriented in space. Stereoisomers have the same molecular weight, chemical composition, and constitution as another, but with the atoms grouped differently. That is, certain identical chemical moieties are at different orientations in space and, therefore, when pure, have the ability to rotate the plane of polarized light. However, some pure stereoisomers may have an optical rotation that is so slight that it is undetectable with present instrumentation. All such isomeric forms of these compounds are expressly included in the present invention.
[0072] Each stereogenic carbon may be of R or S configuration. Although the specific compounds exemplified in this application may be depicted in a particular configuration, compounds having either the opposite stereochemistry at any given chiral center or mixtures thereof are also envisioned. When chiral centers are found in the derivatives of this invention, it is to be understood that this invention encompasses all possible stereoisomers. The terms “optically pure compound” or “optically pure isomer” refers to a single stereoisomer of a chiral compound regardless of the configuration of the compound.
[0073] Exemplary invention compounds of structure I are shown below:
[0000]
[0074] Salinosporamide A exhibits a molecular structure having a variety of functional groups (lactone, alkylhalide, amide, hydroxide) that can be chemically modified to produce synthetic derivatives. Accordingly, exemplary invention compound Salinosporamide A provides an excellent lead structure for the development of synthetic and semisynthetic derivatives. Indeed, Salinosporamide A can be derivatized to improve pharmacokinetic and pharmacodynamic properties, which facilitate administration and increase utility of the derivatives as anti-neoplastic agents. Procedures for chemically modifying invention salinosporamide compounds to produce additional compounds within the scope of the present invention are available to those of ordinary skill in the art.
[0075] Salinosporamide A shows strong cytotoxic activity against human colon cancer cells in the HTC-116 cell assays. The IC 50 of 11 ng/mL exceeds the activity of etoposide (see FIG. 3 , IC 50 828 ng/mL), an anticancer drug used for treatment of a number of cancers, by almost two orders of magnitude (see FIG. 4 ). This high activity makes invention salinosporamides excellent candidates for use in the treatment of various human cancers, especially slow growing, refractile cancers for which there are no therapies. Salinosporamide A is specific to inhibition of mammalian cells and shows little antifungal activity against Candida albicans (IC 50 250 μg/mL) and no antibacterial activity ( Staphylococcus aureus, Enterococcus faecium ). The IC 50 of Salinosporamide A is far lower than the strongest chemotherapeutic agents currently in use or in clinical trials.
[0076] Salinosporamide A is a fermentation product of the marine actinomycete strains CNB392 and CNB476. These strains are members of the order Actinomycetales, which are high G+C gram positive bacteria. The novelty of CNB392 and CNB476 is at the genus level. Invention compounds set forth herein are produced by certain “ Salinospora” sp. In some embodiments, invention compounds are produced by “Salinospora” sp. strains CNB 392 and CNB476. To that end, the CNB392 and CNB476 strains of “Salinospora” sp. were deposited on Jun. 20, 2003, pursuant to the Budapest Treaty on the International Deposit of Microorganisms for the Purposes of Patent Procedure with the Patent Culture Depository of the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852 U.S.A. under ATCC Accession Nos. ______ and PTA-5275, respectively.
[0077] As is the case with other organisms, the characteristics of “Salinospora” sp. are subject to variation. For example, recombinants, variants, or mutants of the specified strain may be obtained by treatment with various known physical and chemical mutagens, such as ultraviolet ray, X-rays, gamma rays, and N-methyl-N′-nitro-N-nitrosoguanidine. All natural and induced variants, mutants, and recombinants of the specified strain which retain the characteristic of producing a compound of the invention are intended to be within the scope of the claimed invention.
[0078] Invention compounds can be prepared, for example, by bacterial fermentation, which generates the compounds in sufficient amounts for pharmaceutical drug development and for clinical trials. In some embodiments, invention compounds are produced by fermentation of the actinomycete strains CNB392 and CNB476 in A1Bfe+C or CKA-liquid media. Essential trace elements which are necessary for the growth and development of the culture should also be included in the culture medium. Such trace elements commonly occur as impurities in other constituents of the medium in amounts sufficient to meet the growth requirements of the organisms. It may be desirable to add small amounts (i.e. 0.2 mL/L) of an antifoam agent such as polypropylene glycol (M. W. about 2000) to large scale cultivation media if foaming becomes a problem. The organic metabolites are isolated by adsorption onto an amberlite XAD-16 resin. For example, Salinosporamide A is isolated by elution of the XAD-16 resin with methanol:dichlormethane 1:1, which affords about 105 mg crude extract per liter of culture. Salinosporamide A is then isolated from the crude extract by reversed-phase flash chromatography followed by reverse-phase HPLC and normal phase HPLC, which yields 6.7 mg of Salinosporamide A. FIG. 5 sets forth a block diagram outlining isolation and separation protocols for invention compounds.
[0079] The structure of Salinosporamide A was elucidated by a variety of NMR techniques, mass spectroscopy, IR, and UV spectroscopy, as set forth in FIGS. 6-14 .
[0080] The absolute structure of salinosporamide A, and confirmation of the overall structure of salinosporamide A, was achieved by single-crystal X-ray diffraction analysis (see Example 3).
[0081] The present invention also provides articles of manufacture including packaging material and a pharmaceutical composition contained within the packaging material, wherein the packaging material comprises a label which indicates that the pharmaceutical composition can be used for treatment of disorders and wherein the pharmaceutical composition includes a compound according to the present invention. Thus, in one aspect, the invention provides a pharmaceutical composition including a compound of the invention, wherein the compound is present in a concentration effective to treat cell proliferative disorders. The concentration can be determined by one of skill in the art according to standard treatment regimen or as determined by an in vivo animal assay, for example.
[0082] Pharmaceutical compositions employed as a component of invention articles of manufacture can be used in the form of a solid, a solution, an emulsion, a dispersion, a micelle, a liposome, and the like, wherein the resulting composition contains one or more invention compounds as an active ingredient, in admixture with an organic or inorganic carrier or excipient suitable for enteral or parenteral applications. Compounds employed for use as a component of invention articles of manufacture may be combined, for example, with the usual non-toxic, pharmaceutically acceptable carriers for tablets, pellets, capsules, suppositories, solutions, emulsions, suspensions, and any other form suitable for use. The carriers which can be used include glucose, lactose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, talc, corn starch, keratin, colloidal silica, potato starch, urea, medium chain length triglycerides, dextrans, and other carriers suitable for use in manufacturing preparations, in solid, semisolid, or liquid form. In addition auxiliary, stabilizing, thickening and coloring agents and perfumes may be used.
[0083] The compositions of the present invention may contain other therapeutic agents as described below, and may be formulated, for example, by employing conventional solid or liquid vehicles or diluents, as well as pharmaceutical additives of a type appropriate to the mode of desired administration (for example, excipients, binders, preservatives, stabilizers, flavors, etc.) according to techniques such as those well known in the art of pharmaceutical formulation.
[0084] Invention pharmaceutical compositions may be administered by any suitable means, for example, orally, such as in the form of tablets, capsules, granules or powders; sublingually; buccally; parenterally, such as by subcutaneous, intravenous, intramuscular, or intracisternal injection or infusion techniques (e.g., as sterile injectable aqueous or non-aqueous solutions or suspensions); nasally such as by inhalation spray; topically, such as in the form of a cream or ointment; or rectally such as in the form of suppositories; in dosage unit formulations containing non-toxic, pharmaceutically acceptable vehicles or diluents. Invention compounds may, for example, be administered in a form suitable for immediate release or extended release. Immediate release or extended release may be achieved by the use of suitable pharmaceutical compositions comprising invention compounds, or, particularly in the case of extended release, by the use of devices such as subcutaneous implants or osmotic pumps. Invention compounds may also be administered liposomally.
[0085] The invention further provides methods for using invention salinosporamide compounds of structures (I)-(VI) to inhibit the proliferation of mammalian cells by contacting these cells with an invention salinosporamide compound in an amount sufficient to inhibit the proliferation of the mammalian cell. One embodiment is a method to inhibit the proliferation of hyperproliferative mammalian cells. For purposes of this invention, “hyperproliferative mammalian cells” are mammalian cells which are not subject to the characteristic limitations of growth, e.g., programmed cell death (apoptosis). A further preferred embodiment is when the mammalian cell is human. The invention further provides contacting the mammalian cell with at least one invention salinosporamide compound and at least one additional anti-neoplastic agent.
[0086] In another embodiment, there are provided methods for treating a mammalian cell proliferative disorder, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of structures (I)-(VI). Cell proliferative disorders that can be effectively treated by the methods of the invention include disorders characterized by the formation of neoplasms. As such, invention compounds are anti-neoplastic agents. As used herein, “neoplastic” pertains to a neoplasm, which is an abnormal growth, such growth occurring because of a proliferation of cells not subject to the usual limitations of growth. As used herein, “anti-neoplastic agent” is any compound, composition, admixture, co-mixture or blend which inhibits, eliminates, retards or reverses the neoplastic phenotype of a cell. In certain embodiments, the neoplasms are selected from mammary, small-cell lung, non-small-cell lung, colorectal, leukemia, melanoma, pancreatic adenocarcinoma, central nervous system (CNS), ovarian, prostate, sarcoma of soft tissue or bone, head and neck, gastric which includes thyroid and non-Hodgkin's disease, stomach, myeloma, bladder, renal, neuroendocrine which includes thyroid and non-Hodgkin's disease and Hodgkin's disease neoplasms. In one embodiment, the neoplasms are colorectal.
[0087] Chemotherapy, surgery, radiation therapy, therapy with biologic response modifiers, and immunotherapy are currently used in the treatment of cancer. Each mode of therapy has specific indications which are known to those of ordinary skill in the art, and one or all may be employed in an attempt to achieve total destruction of neoplastic cells. Chemotherapy utilizing one or more invention salinosporamide compounds is provided by the present invention. Moreover, combination chemotherapy, chemotherapy utilizing invention salinosporamide compounds in combination with other neoplastic agents, is also provided by the invention as combination therapy is generally more effective than the use of single anti-neoplastic agents. Thus, a further aspect of the present invention provides compositions containing a therapeutically effective amount of at least one invention salinosporamide compound in combination with at least one other anti-neoplastic agent. Such compositions can also be provided together with physiologically tolerable liquid, gel or solid carriers, diluents, adjuvants and excipients. Such carriers, diluents, adjuvants and excipients may be found in the United States Pharmacopeia Vol. XXII and National Formulary Vol XVII, U.S. Pharmacopeia Convention, Inc., Rockville, Md. (1989), the contents of which are herein incorporated by reference. Additional modes of treatment are provided in AHFS Drug Information, 1993 ed. by the American Hospital Formulary Service, pp. 522-660, the contents of which are herein incorporated by reference.
[0088] Anti-neoplastic agents which may be utilized in combination with an invention salinosporamide compound include those provided in The Merck Index, 11th ed. Merck & Co., Inc. (1989) pp. Ther 16-17, the contents of which are hereby incorporated by reference. In a further embodiment of the invention, anti-neoplastic agents may be antimetabolites which may include, but are not limited to, methotrexate, 5-fluorouracil, 6-mercaptopurine, cytosine arabinoside, hydroxyurea, and 2-chlorodeoxyadenosine. In another embodiment of the present invention, the anti-neoplastic agents contemplated are alkylating agents which may include, but are not limited to, cyclophosphamide, melphalan, busulfan, paraplatin, chlorambucil, and nitrogen mustard. In a further embodiment of the invention, the antineoplastic agents are plant alkaloids which may include, but are not limited to, vincristine, vinblastine, taxol, and etoposide. In a further embodiment of the invention, the anti-neoplastic agents contemplated are antibiotics which may include, but are not limited to, doxorubicin (adriamycin), daunorubicin, mitomycin c, and bleomycin. In a further embodiment of the invention, the anti-neoplastic agents contemplated are hormones which may include, but are not limited to, calusterone, diomostavolone, propionate, epitiostanol, mepitiostane, testolactone, tamoxifen, polyestradiol phosphate, megesterol acetate, flutamide, nilutamide, and trilotane. In a further embodiment of the invention, the anti-neoplastic agents contemplated include enzymes which may include, but are not limited to, L-Asparaginase or aminoacridine derivatives which may include, but are not limited to, amsacrine. Additional anti-neoplastic agents include those provided in Skeel, Roland T., “Antineoplastic Drugs and Biologic Response Modifier: Classification, Use and Toxicity of Clinically Useful Agents,” Handbook of Cancer Chemotherapy (3rd ed.), Little Brown & Co. (1991), the contents of which are herein incorporated by reference.
[0089] In addition to primates, such as humans, a variety of other mammals can be treated according to the method of the present invention. For instance, mammals including, but not limited to, cows, sheep, goats, horses, dogs, cats, guinea pigs, rats or other bovine, ovine, equine, canine, feline, rodent or murine species can be treated.
[0090] The term “therapeutically effective amount” means the amount of the subject compound that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician, e.g., lessening of the effects/symptoms of cell proliferative disorders.
[0091] By “pharmaceutically acceptable” it is meant the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
[0092] The terms “administration of” and or “administering a” compound should be understood to mean providing a compound of the invention to the individual in need of treatment. Administration of the invention compounds can be prior to, simultaneously with, or after administration of another therapeutic agent or other anti-neoplastic agent.
[0093] The pharmaceutical compositions for the administration of the compounds of this invention may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the active ingredient into association with the carrier which constitutes one or more accessory ingredients. In general, the pharmaceutical compositions are prepared by uniformly and intimately bringing the active ingredient into association with a liquid carrier or a finely divided solid carrier or both, and then, if necessary, shaping the product into the desired formulation. In the pharmaceutical composition the active object compound is included in an amount sufficient to produce the desired effect upon the process or condition of diseases.
[0094] The pharmaceutical compositions containing the active ingredient may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs.
[0095] Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated to form osmotic therapeutic tablets for control release.
[0096] Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil.
[0097] Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydroxy-propylmethylcellulose, sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.
[0098] Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.
[0099] Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
[0100] Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents.
[0101] The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
[0102] The compounds of the present invention may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.
[0103] For topical use, creams, ointments, jellies, solutions or suspensions, etc., containing the compounds of the present invention are employed.
[0104] Compounds and compositions of the invention can be administered to mammals for veterinary use, such as for domestic animals, and clinical use in humans in a manner similar to other therapeutic agents. In general, the dosage required for therapeutic efficacy will vary according to the type of use and mode of administration, as well as the particularized requirements of individual hosts. Ordinarily, dosages will range from about 0.001 to 1000 μg/kg, more usually 0.01 to 10 μg/kg, of the host body weight. Alternatively, dosages within these ranges can be administered by constant infusion over an extended period of time, usually exceeding 24 hours, until the desired therapeutic benefits have been obtained. It will be understood, however, that the specific dose level and frequency of dosage for any particular patient may be varied and will depend upon a variety of factors including the activity of the specific compound employed, the metabolic stability and length of action of that compound, the age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the particular condition, and the host undergoing therapy.
[0105] The invention will now be described in greater detail by reference to the following non-limiting examples.
EXAMPLES
Methods and Materials
[0106] HPLC-Purification of invention compounds was accomplished by RP-MPLC on C18-solid phase (Aldrich) using a step gradient on Kontes Flex-columns (15×7 mm). Semipreparative HPLC was performed on an isocratic HPLC system with a Waters pump 6000H on normal phase column Si-Dynamas-60 Å (250×5 mm) or reversed phase column C18-Dynamax-60 Å, flow 2 mL/minute, with a differential refractomeric detector Waters R401.
[0107] LC-MS-The LC-MS chromatography was performed on a Hewlett-Packard system series HP1100 with DAD and MSD1100 detection. The separation was accomplished on reversed phase C18 (Agilent Hypersil ODS 5 μm, column dimension 4.6×100 mm), flow rate 0.7 mL/minute using a standard gradient: 10% acetonitrile, 15 minutes; 98% acetonitrile (Burdick & Jackson high purity solvents). The MS-detection was in ESI positive mode, capillary voltage 3500 eV, fragmentation voltage 70 eV, mass range m/z 100-1000. The APCI-mode was measured at a flow rate of 0.5 mL/minute, positive detection, capillary voltage 3000 eV, fragmentation voltage 70 eV.
[0108] NMR-NMR spectra were measured on a Varian 300 MHz gradient field spectrometer with inverse-mode for 1 H or 2D-NMR spectra. The 13C and DEPT spectra were measured on a Varian 400 MHz, broad band instrument. The reference is set on the internal standard tetramethylsilane (TMS, 0.00 ppm).
[0109] MS-EI-Low resolution MS-EI spectra were performed on a Hewlett-Packard mass spectrometer with magnetic sector field device, heating rate 20° C./minute up to 320° C., direct injection inlet.
[0110] FTMS-MALDI-High resolution MS data were obtained by MALDI operating mode on an IonSpec Ultima FT Mass Spectrometer.
[0111] IR-Infrared spectra were measured on a Perkin-Elmer FT infrared spectrophotometer using NaCl windows.
Example 1
Isolation and Characterization of “Salinospora” Species, Culture Nos. CNB392 and CNB476
[0112] CNB392 and CNB476 possess signature nucleotides within their 16S rDNA which separate these strains phylogenetically from all other members of the family Micromonosporaceae (see FIG. 15 ) These signature nucleotides have been determined to be a definitive marker for members of this group which also have a physiological growth requirement of sodium. Signature nucleotides were aligned to E. coli positions 27-1492 using all existing members of the Micromonosporaceae in the Ribosomal Database Project as of 1-31-01. For the “Salinospora” clade, 45 partially sequenced morphotypes displayed all the signature nucleotides from positions 207-468. The seven “Salinospora” isolates sequenced almost in their entirety (see FIG. 2 ) displayed all of the signatures in FIG. 15 .
[0113] The strains CNB392 and CNB476 form bright orange to black colonies on agar and lacks aerial mycelia. Dark brown and bright orange diffusible pigments are produced depending upon cellular growth stage. Spores blacken the colony surface and are borne on substrate mycelia. Vegetative mycelia are finely branched and do not fragment. Spores are produced singly or in clusters. Neither sporangia nor spore motility has been observed for these strains. CNB392 and CNB476 have an obligate growth requirement for sodium and will not grow on typical media used for maintenance of other generic members of the Micromonosporaceae. CNB392 and CNB476 have been found to grow optimally on solid media TCG or M1 at 30° C.
[0000]
TCG
3 grams tryptone
M1
10 grams starch
5 grams casitone
4 grams yeast extract
4 grams glucose
2 grams peptone
18 grams agar (optional)
18 grams agar (optional)
1 liter filtered seawater
1 liter filtered seawater
Fermentation
[0114] CNB392 and CNB476 are cultured in shaken A1Bfe+C or CKA-liquid media, 1 liter at 35° C. for 9 days. After 4 days 20 grams Amberlite XAD-16 resin (Sigma, nonionic polymeric adsorbent) is added.
[0000]
A1Bfe + C
10 grams starch
CKA
5 grams starch
4 grams yeast extract
4 mL hydrosolubles (50%)
2 grams peptone
2 grams menhaden meal
1 gram CaCO 3
2 grams kelp powder
5 mL KBr (aqueous solution, 20 grams/liter)
2 grams chitosan
5 mL Fe 2 (SO 4 ) 3 × 4 H 2 O (8 grams/liter)
1 liter filtered seawater
1 liter filtered seawater
Extraction
[0115] The XAD-16 resin is filtered and the organic extract is eluted with 1 liter ethylacetate followed by 1 liter methanol. The filtrate is then extracted with ethylacetate (3×200 mL). The crude extract from the XAD adsorption is 105 mg. Cytotoxicity on the human colon cancer cell HCT-116 assay is IC50<0.076 μg/mL.
[0000] Isolation of Salinosporamide A from CNB392
[0116] The crude extract was flash-chromatographed over C18 reversed phase (RP) using a step gradient ( FIG. 5 ). The HCT-116 assay resulted in two active fractions, CNB392-5 and CNB392-6. The combined active fractions (51.7 mg), HCT-116<0.076 μg/mL) were then chromatographed on an isocratic RP-HPLC, using 85% methanol at 2 mL/minute flow as eluent and using refractive index detection. The active fraction CNB392-5/6 (7.6 mg, HCT-116<0.076 μg/mL) was purified on an isocratic normal phase HPLC on silica gel with ethyl acetate:isooctane (9:1) at 2 mL/minute. Salinosporamide A ( FIG. 1 ) was isolated as a colorless, amorphous solid in 6.7 mg per 1 liter yield (6.4%). TLC on silica gel (dichloromethane:methanol 9:1) shows Salinosporamide A at r f =0.6, no UV extinction or fluorescence at 256 nm, yellow with H 2 SO 4 /ethanol, dark red-brown with Godin reagent (vanillin/H 2 SO 4 /HClO 4 ). Salinosporamide A is soluble in CHCl 3 , methanol, and other polar solvents like DMSO, acetone, acetonitrile, benzene, pyridine, N,N-dimethylformamide, and the like. 1 H NMR: (d 5 -pyridine, 300 MHz) 1.37/1.66 (2H, m, CH 2 ), 1, 70.2.29 (2H, m, CH 2 ), 1.91 (2H, broad, CH 2 ), 2.07 (3H, s, CH 3 ), 2.32/2.48 (2H, ddd, 3 J=7.0 Hz, CH 2 ), 2.85 (1H, broad, m, CH), 3.17 (1H, dd, 3 J=10 Hz, CH), 4.01/4.13 (2H, m, CH 2 ), 4.25 (1H, d, 3 J=9.0 Hz, CH), 4.98 (1H, broad, OH), 5.88, (1H, ddd, 3 J=10 Hz, CH), 6.41 (1H, broad d, 3 J=10 Hz, CH) 10.62 (1H, s, NH). 13 C NMR/DEPT: (d 5 -pyridine, 400 MHz) 176.4 (COOR), 169.0 (CONH), 128.8 (═CH), 128.4 (═CH), 86.1 (C q ), 80.2 (C q ), 70.9 (CH), 46.2 (CH), 43.2 (CH 2 ), 39.2 (CH), 29.0 (CH 2 ), 26.5 (CH 2 ), 25.3 (CH 2 ), 21.7 (CH 2 ), 20.0 (CH 3 )
[0117] LC-MS (ESI) t r =10.0 minutes, flow 0.7 mL/minute
[0118] m/z: (M+H) + 314, (M+Na) + 336; fragments: (M+H—CO 2 ) + 292, (M+H—CO 2 —H 2 O) + 270, 252, 204. C1 pattern: (M+H, 100%) + 314, (M+H, 30%) + 316.
[0119] LC MS (APCI): t r =11.7 minutes, flow 0.5 mL/minute
[0120] m/z: (M+H) + 314, fragments: (M+H—CO 2 —H 2 O) + 270, 252, 232, 216, 160. C1 pattern: (M+H, 100%) + 314, (M+H, 30%) + 316.
[0121] EI: m/z: 269, 251, 235, 217, 204, 188 (100%), 160, 152, 138, 126, 110, 81.
[0122] FTMS-MALDI: m/z: (M+H) + 314.1144
[0123] FT-IR: (cm −1 ) 2920, 2344, s, 1819 m, 1702 s, 1255, 1085 s, 1020 s, 797 s.
[0124] Molecular formula: C 15 H 20 ClNO 4
Example 2
Bioactivity Assays
[0125] Salinosporamide A shows strong activity against human colon cancer cells with an IC 50 of 0.011 μg/mL (see FIG. 4 ). The screening on antibacterial or antifungal activity shows no significant activity, see Table 1.
[0000]
TABLE 1
IC 50 of Salinosporamide A,
Assay
(μg/mL)
HCT-116
0.011
Candida albicans
250
Candida albicans (amphoterocin B resistant)
NSA*
Staphylococcus aureus (methecillin resistant)
NSA*
Enterococcus faecium (vanomycin resistant)
NSA*
*NSA = no significant activity
Example 3
Determination of Absolute Stereochemistry
[0126] Crystallization of a compound of structure I from ethyl acetate/iso-octane resulted in single, cubic crystals, which diffracted as a monoclinic system P2(1). The unusual high unit-cell volume of 3009 Å hosted four independent molecules in which different conformational positions were observed for the flexible chloroethyl substituent. The assignment of the absolute structure from the diffraction anisotropy of the chlorine substituent resolved the absolute stereochemistry of salinosporamide A as 2R, 3S, 4R, 5S, 6S ( FIGS. 16 and 17 ) with a Flack parameter of 0.01 and an esd of 0.03.
[0127] Although the invention has been described with reference to the above examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims.
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The present invention is based on the discovery that certain fermentation products of the marine actinomycete strains CNB392 and CNB476 are effective inhibitors of hyperproliferative mammalian cells. The CNB392 and CNB476 strains lie within the family Micromonosporaceae, and the generic epithet Salinospora has been proposed for this obligate marine group. The reaction products produced by this strain are classified as salinosporamides, and are particularly advantageous in treating neoplastic disorders due to their low molecular weight, low IC 50 values, high pharmaceutical potency, and selectivity for cancer cells over fungi.
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FIELD OF THE INVENTION
The present invention generally relates to an high-voltage connection enclosure and more particularly, to an improved enclosure for connecting high-voltage cables connected to high-voltage gas-filled tubes, for example, neon tubes used for signage.
BACKGROUND OF THE INVENTION
High-voltage, gas-filled tubes have been widely used for signage for decades. Some neon signage has the gas-filled tubes depicting letters and numbers completely enclosed in a housing that protects the electrical components and electrical connections from the weather. With other sign constructions, the sign is composed of individual gas-filled tubes representing letters and numbers that are individually mounted to an exterior wall or other surface of a structure without the benefit of an enclosure over all of the components. In that construction, the individual gas-filled tubes must be wired together in a high-voltage circuit that is powered from a secondary winding of a transformer. In a known manner, the wire from a gas-filled neon tube has an electrode that is connected to a conductor or wire, for example, a high-voltage gaseous tube and oil ignition (“GTO”) cable. In many applications, the electrical connection between the neon tube electrode and one end of the high-voltage GTO cable is accomplished utilizing a known connector P-K connector. The other end of the GTO cable is then connected to either one side of the secondary winding of the transformer or an electrode of an adjacent gas-filled neon tube. Thus, the gas-filled neon tubes are connected in series with the secondary winding of the transformer. In some applications, a single GTO cable is connected to adjacent gas-filled tubes. While such a connection would seem to be efficient, since the PK connectors are often located within a wall of the structure, the diagnosis and correction of a fault is time consuming and difficult. In other applications, a GTO cable from one gas-filled tube is connected or spliced with a GTO cable from an adjacent gas-filled tube in a junction box. Such known junction boxes have at least one electrically conductive terminal to which the ends of both GTO cables are mechanically connected and secured, thereby electrically connecting the GTO cables together. Other terminal boxes have two electrically conductive terminals connected with a electrically conductive bar, and an end of each of the GTO cables is attached to one of the terminals.
Such junction boxes permit gas-filled neon tubes to be very easily connected together. In some applications, the P-K connectors extend through the exterior wall of a building; and the junction boxes are in a relatively protected environment. In other applications, the P-K connectors and the junction boxes are mounted on the exterior wall of the building, and thus, must be impervious to harsh weather conditions.
Of significant concern is the potential for arcing or a short circuit between the exposed ends of the GTO cable and any grounded metal component within the junction box. To minimize the potential for arcing within the junction box, regulations are implemented setting forth a minimum distance between a cable connection and a metal portion of the junction box. Over the years, the specified minimum distance has increased, and more recent regulations may require different minimum distances depending on whether the junction box is located inside or outside a structure. Operating in an environment in which the regulations constantly change is a particular challenge with respect to the junction box design.
Further, there is a continuing requirement to make junction boxes more reliable and easier to use. For example, some junction box designs have various loose parts that must be assembled in the process of splicing two cables together. Further, after the cable splice is made and the junction box is permanently mounted, all junction boxes are opaque; and therefore, the junction box must be opened or partially disassembled to check the integrity of the splice.
Therefore, there is a need for an improved enclosure for connecting the ends of high-voltage GTO cables that can be readily changed to meet regulations that are constantly changing. Further, there is a need for a junction box that permits the integrity of the splice to be checked without having to disassemble the junction box. Further, there is a need for a junction box design that is easier to handle in the connecting of the GTO cables.
SUMMARY OF INVENTION
The present invention provides a high-voltage connection enclosure that is less susceptible to arcing and short circuits that may potentially result in a fire. The enclosure of the present invention is easy to use and permits a visual inspection of the electrical connection between two GTO cables without having to remove a cover or in any way disassemble the enclosure. Further, the enclosure of the present invention automatically secures the GTO cables in the enclosure as an enclosure cover is attached. Thus, the present invention provides a more consistent, reliable and higher quality, high-voltage electrical connection between ends of GTO cables. The invention is especially useful in providing an electrical connection with a high-voltage, gas-filled tube used for signage in which the electrical connection is exposed to a wide range of temperature and moisture conditions.
In accordance with the principles of the present invention and the described embodiments, an apparatus is provided for enclosing an electrical connection between two high-voltage cables. The apparatus has an electrically nonconductive separator integral with a mounting base for receiving the high-voltage cables. An electrically nonconductive tubular cover extends over the electrical connection and the high-voltage cables and is releasably attached to the mounting base.
In one aspect of the invention, the separator has two passages in a base portion to separately receive the high-voltage cables. The high-voltage cables are extended beyond the mounting base, so that the electrical connection is separated from an electrically conductive portion of the mounting base by a desired spacing. The separator also has fingers that are moved by the tubular cover into contact with the high-voltage cables to secure the high-voltage cables in the separator.
In a still further aspect of the invention the electrically nonconductive cover is sufficiently transparent so that the electrical connection joining the high-voltage cables can be visually inspected through the cover.
In another embodiment, the present invention includes a method of electrically connecting two high-voltage cables by first inserting each of the high-voltage cables into a separate passage formed of a nonconductive material integral with a mounting base. Next the high-voltage cables are extended a distance beyond the mounting base equal to a desired separation between an electrical connection between the cables and an electrical conductor associated with the mounting base. The ends of the high-voltage cables are joined together to form the electrical connection; and then, an electrically nonconductive tubular cover is placed over the electrical connection and the high voltage cables and is releasably attached to the mounting base.
In an aspect of that invention, the method further comprises securing the high-voltage cables in the mounting base.
Various additional advantages, objects and features of the invention will become more readily apparent to those of ordinary skill in the art upon consideration of the following detailed description of the presently described embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a disassembled perspective view of a high-voltage connection enclosure in accordance with the principles of the present invention.
FIG. 2 is a top view of the assembled high-voltage connection enclosure illustrated in FIG. 1 .
FIG. 3 is a schematic block diagram of a circuit illustrating the use of the high-voltage connection enclosure illustrated in FIG. 1 .
FIG. 4 is an enlarged cross-sectional view taken along line 4 — 4 of FIG. 2 and illustrates the locking of GTO cables in the high-voltage connection enclosure illustrated in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the high-voltage connection enclosure 20 is comprised of a mounting base 22 , a mounting base bracket 24 , a separator 26 , a cover or tubular body 28 and a tube clamp 30 . The mounting base 22 has two opposed cavities 32 , 34 that have generally circular outer wall portions that are sized to receive flexible metal cable that is typically used. The cavities 32 , 34 have a depth that permit the metal flexible conduit to be inserted until it hits a rear surface 33 of a top wall 36 of the mounting base 22 . Mounting legs 38 extend laterally away from the rear side 40 of the mounting base 22 and have mounting feet 42 formed on their distal ends. The mounting feet 42 have through holes 44 that accept fasteners for attaching the mounting base 22 to a surface. A hollow cylindrical tube mount 46 extends from the top 48 of the mounting base 22 . The tube mount 46 is equally spaced between the cavities 32 , 34 , and the tube mount 46 has a cylindrical through bore 47 intersecting the cavities 32 , 34 . The front side 50 of the mounting base 22 has a clearance hole 52 for receiving a fastener 54 that threadedly engages a hole 56 within the bracket 24 . The cavities 32 , 34 have an extension or hood 58 on the front side 50 of the mounting base 22 . The mounting base bracket 24 is located immediately below the extension 58 and has ears 60 , 62 for engaging and locking into grooves in the metal flexible conduit disposed in the respective cavities 32 , 34 .
The separator 26 has a spacer wall 66 extending from a base portion 68 . The separator 26 is located in the mounting base 22 and through the tube mount 46 at an orientation such that the spacer wall 66 is substantially perpendicular to a line joining the centers of the cavities 32 , 34 . In other words, the spacer wall 66 bisects the internal bore 47 of the tube mount 46 along a diameter bisecting the top and bottom sides 50 , 40 , respectively, of the mounting base 22 . The base 68 of the separator 26 has a retaining flange or lip 70 with diametrically opposed locating tabs 72 , 74 . The spacer wall 66 extends through the base 68 and has a bottom end 76 formed with the retaining lip 70 . A segmented bushing 82 is formed with the retaining lip 70 and has a plurality of through slots 84 between segments 86 to permit radially inward motion of the segments 86 during the mounting of the separator 26 within the mounting base 22 . A plurality of locking teeth or fingers 88 are formed on an inner end of the segmented bushing 82 . The plurality of fingers 88 are cantilevered from the retaining ring 70 , and each of the fingers 88 along with a corresponding bushing segment 86 is resiliently, pivotable with respect to the retaining ring 70 . Therefore, the fingers 88 are independently movable in a generally radial direction with respect to the generally cylindrical bushing 82 . The slots 84 extend between the locking fingers 88 to facilitate a radially inward deformation of the locking fingers 88 in the assembly process.
To assemble the separator 26 in the mounting base 22 , the spacer wall 66 is inserted into the bore 47 of the tube mount 46 from the mounting base bottom side 35 . Upon the fingers 88 contacting an edge of the bore 47 of the tube mount 46 , angled surfaces 90 of the fingers 88 facilitate compression of the fingers in response to an axial force being applied against the bottom surface 76 of the retaining lip 70 . As the plurality of fingers 88 and bushing segments 82 move radially inward, the plurality of fingers 88 slide through the bore 47 of the tube mount 46 . As shown in FIG. 1, two opposed projections 89 are aligned with and extend radially from opposite edges 91 of the spacer wall 66 . The projections 89 are radially smaller than the fingers 88 and normally pass through the bore 47 without contacting the walls of the bore 47 . The axial length of the segmented bushing 82 is slightly larger than the axial length of the tube mount 46 (FIG. 2 ). Therefore, as the locating tabs 72 , 74 contact the inside surface 33 of the front wall 36 , the plurality of fingers 88 pass the top edge 92 of the tube mount 46 and expand radially outward. The top edge 92 of the tube mount 46 locks behind the plurality of fingers 88 , thereby permanently locking the separator 26 into the mounting base 22 and forming an integral unit therewith. The fingers 88 have a length such that they extend radially beyond a cylindrical outer surface 93 of the tube mount 46 . Referring to FIG. 1, the ends of the tabs 72 , 74 are sized to contact an inner, generally spherically shaped portion of the front wall 36 of the mounting base 22 , thereby preventing the separator 26 from rotating within the mounting base 22 .
The tubular body or tube 28 has a closed end 100 and an annular flange 102 at its opposite open end 104 . The tube 28 has an inner, generally cylindrical cavity 105 with a diameter that is slightly larger than the outer diameter of the tube mount 46 . However, the diameter of the cavity 105 is slightly smaller than a diameter extending across the fingers 88 . The spacer wall 66 of the separator 26 as assembled in the mounting base 22 extends outward from the tube mount 46 . After electrically connecting the GTO cables as will be described, the assembly of the high-voltage connection enclosure 20 is completed by sliding the tube 28 over the separator 26 , over the fingers 88 and securing the tube 28 against the mounting base 22 with a tube clamp 30 . Thus, the tube 28 completely encloses the spacer wall 66 and depresses the fingers 88 slightly radially inward. The tube clamp 30 has a cylindrical tubular body 110 that slides over an outer, generally cylindrical surface of the tube 28 . The tube clamp body 110 has an annular bottom edge 112 that contacts an annular top surface 114 of the flange 102 of the tube 28 . The tube clamp 30 also has two diametrically opposed spring arms or clips 116 that are pressed together to cause the arms to extend, thereby permitting ends 118 of the arms 116 to be located in notches 120 , thereby securing the tube 28 to the mounting base 22 . The fully assembled high-voltage connection enclosure 20 is shown in FIG. 2 .
Referring again to FIG. 1, the spacer wall 66 extends through and generally bisects the segmented bushing 82 and the retaining lip 70 to form two generally semicircular passages or through holes 96 , 98 . Passage 96 extends through the retaining lip 70 and the segmented bushing 82 of the base 68 and opens to one side 97 of the spacer wall 66 . Passage 98 similarly extends through the retaining lip 70 and the segmented bushing 82 of the base 68 and opens to an opposite side 99 of the spacer wall 66 .
The mounting base 22 and bracket 24 are normally made from an electrically conductive material, for example, a cast zinc. The electrically conductive material is chosen for reasons of cost and physical strength. The separator 26 is normally made from an electrically nonconductive material, for example, a “LEXAN” 503 plastic material; however as will be appreciated other electrically nonconductive materials may be used. The tubular body 28 is also made from an electrically nonconductive material, for example, a clear or transparent glass; but as will be appreciated, other electrically nonconductive materials may be used.
In use, referring to FIG. 3, the high-voltage connection enclosures 20 are typically used in a serial circuit with high-voltage, gas-filled tubes 122 , for example, neon tubes. Each end of the gas-filled tubes 122 has an electrode that is connected to a GTO cable 126 , 128 inside a PK connector 130 . The gas-filled tubes 122 are wired together in a serial circuit that is powered from a secondary winding from a transformer 124 . Thus, the first and last gas-filled tubes 122 have one electrode connected to first ends of GTO cables 126 . In a known manner, the GTO cables 126 are normally routed through sections of conduit 129 , for example, a flexible metal conduit; and the opposite ends of the GTO cables 126 are connected to a secondary winding of a transformer 124 . The other electrodes of the gas-filled tubes 122 are connected via GTO cables 128 that are routed in respective sections of conduit 131 and connected together in a junction box, for example, the high-voltage connection enclosure 20 .
In making an electrical connection or a splice, the tube clamp 30 is disengaged; and the tube clamp 30 and tube 28 are removed from the mounting base 22 . Further, the fastener 54 is loosened to loosen the mounting base bracket 24 . Referring to FIGS. 1 and 2, a length of GTO cable 132 extending from the end of one of the metallic flexible conduits 134 is inserted into the cavity 32 through the first passage 96 and along the one side 97 of the spacer wall 66 . A length of the GTO cable 132 should extend beyond the distal end 136 of the spacer wall 66 . In a similar manner, a second GTO cable 138 extending from the end of a metallic flexible conduit 140 is threaded through the cavity 34 , the second passage 98 and along the opposite side 99 of the spacer wall 66 . Again, a length of GTO cable 138 should extend beyond the distal end 136 of the spacer wall 66 . Referring to FIG. 4, it should be noted that the cavities 96 , 98 are nominally sized such that the outer surfaces of the GTO cables 132 , 138 just touch the respective opposite sides 97 , 99 of the spacer wall 66 and the respective opposed inner surfaces 101 , 103 of the respective fingers 88 a , 88 b . Referring to FIG. 2, the conduits 134 , 140 are then inserted in the respective cavities 32 , 34 , and the fastener 54 is tightened, Tightening the fastener 54 clamps the mounting base bracket 24 tightly against the conduits 134 , 140 . The ears 60 , 62 on the bracket 24 engage or penetrate an external feature of the conduits 134 , 140 , thereby more firmly securing the conduits to the mounting base 22 . For example, if the conduits 134 , 140 are metal flexible conduits, the ears 60 , 62 lock into helical grooves extending over an exterior surface of the metal conduits 134 , 140 . As the fastener 54 is tightened and the mounting base bracket brought up against the conduits 134 , 140 , a rearward extending flange or cover 141 of the bracket 24 functions to cover the cavities 32 , 34 . The ends of the respective GTO cables 132 , 138 extending beyond the distal end 136 of the spacer wall 66 are stripped to bear respective conductors or wires 142 , 144 . The wires 142 , 144 are twisted together or otherwise joined with an electrical connector to form a high-voltage electrical connection 146 beyond the distal end 136 of the spacer wall 66 .
Thus, the separator 26 performs several functions. First, the openings 96 , 98 provide paths for the GTO cables through the mounting base 22 that protect the cables from scuffing or physical damage from any edges or other physical features of the mounting base 22 . Further, the separator spacer wall 66 has a length that guarantees a spacing or separation between the high-voltage electrical connection 146 and any metal components, for example, the front wall 36 of the mounting base 22 . That separation or spacing is often determined by UL regulations. Further, different spacing or separations are readily obtained by simply changing the length of the spacer wall 66 and the tube 28 . In addition, the spacer wall 66 provides mechanical support for the high-voltage connection 146 immediately adjacent its distal end 136 .
After the high-voltage electrical connection 146 is made, the clear tubular body 28 is slid over the connection 146 , the GTO cables 132 , 138 , spacer wall 66 and the fingers 88 . The inner diameter of the cavity 105 of the tubular body 28 is slightly smaller than a diameter extending across the fingers 88 . Therefore, referring to FIG. 4, as the cylindrical inner surface 107 of the tubular body 28 is slid over the fingers 88 , the fingers 88 are deflected or forced radially inward. A lower corner or edge surface 101 at the intersection of the tooth 88 a with its corresponding segment 86 a is pushed into the outer surface of the cable 132 . That deflection of the tooth 88 a and segment 86 a functions to lock the cable in the cavity 96 and resists forces on the cable 132 occurring in a direction toward the viewer of FIG. 4. A lower corner or edge surface 103 at the intersection of the tooth 88 b with its corresponding segment 86 b is pushed into the outer surface of the cable 138 , thereby locking the cable 138 in the cavity 98 .
Upon sliding the tubular body 28 over the fingers 88 , the bottom surface 106 on flange 102 of the tubular body 28 contacts a forward surface 108 on the mounting base 22 . Thereafter, the cylindrical body 110 of the tube clamp 30 is slid over the tubular body 28 until the bottom edge 112 of the cylindrical body 110 contacts an upper annular surface 114 of the flange 102 . The spring arms 116 are then manually compressed until the arm ends 118 slide into the locking notches 120 . Upon releasing the spring arms 116 , the ends 118 of the spring arms 116 are secured in the notches 120 , thereby securing the tubular body 28 to the mounting base 22 . If not already permanently mounted, the mounting base is then mounted on a wall with the clear tubular body pointing in the vertically upward direction.
The high-voltage connection enclosure 20 provides a connection enclosure for interconnecting high-voltage, gas-filled tubes that is less susceptible to arcing and short circuits which may lead to a fire when exposed to a wide range of temperature and moisture conditions. With the high-voltage connection enclosure described herein, the separator 26 is fixed in the mounting base 22 ; and therefore, routing the GTO cables and making the electrical connection is very easy. Further, the clear glass tubular cover not only provides superior, long term electrical insulating capability, but the clear cover permits an immediate visual inspection of the electrical connection without having to remove a cover or disassemble the enclosure in any way. Being able to quickly determine the mechanical integrity of the electrical connection makes diagnostic and maintenance procedures much less time consuming and more efficient. Thus, the high-voltage connection enclosure provides a consistent, reliable and high quality, high-voltage electrical connection between ends of GTO cables.
While the present invention has been illustrated by a description of various described embodiments and while these embodiments have been described in considerable detail, it is not the intention of Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. For example, in the described embodiment, the tubular body 28 is described as a generally cylindrical body which has a generally circular cross-sectional shape. As will be appreciated, the tubular body 28 may have any cross-sectional shape, for example, noncircular or multilateral. Further, the tubular body is described as being secured by a spring clamp 30 ; however, as will be appreciated, the tubular body may be secured to the mounting base 22 by other means, for example, a threaded connection. Further, the tube clamp 30 may be made from a metal, plastic or other material that provides the necessary function. In addition, as will be appreciated, in the assembly of the tubular body 28 onto the mounting base 22 , it may be desirable to mounted the end 106 of the tubular body 28 against an O-ring located over the circular mount 46 and against the forward surface 108 .
Further, in the described embodiment, the separator 66 is secured to the mounting base 22 by resilient fingers 88 to form a unitary structure with the mounting base. While a plurality of circumferentially arranged fingers 88 is described, a single or any number of fingers may be used. In addition, as will be appreciated, instead of using the fingers 88 , the separator 26 may be connected to the mounting base 22 by adhesives, welding, threads or other means. Alternatively, the mounting base 22 and separator 26 may be manufactured as a single unitary structure.
The description of the tubular body 28 as being clear glass means that the tubular body is sufficiently translucent or transparent so that the electrical connection may be visually inspected through the cover. Alternatively, the tubular body may also be opaque although the advantage of visual inspection will be lost. As will be further appreciated, even though glass has excellent long term electrically insulation properties, the tubular body 28 may be made of other electrically nonconductive materials.
Therefore, the invention in its broadest aspects is not limited to the specific detail shown and described. Consequently, departures may be made from the details described herein without departing from the spirit and scope of the claims which follow.
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An enclosure for an electrical connection between two high-voltage cables that includes an electrically nonconductive separator integral with a mounting base for receiving the high-voltage cables. An electrically nonconductive tubular cover extends over the electrical connection and the high-voltage cables and is releasably attached to the base. The separator has at least two resiliently mounted fingers, and the electrically nonconductive cover extends over the fingers to depress and move the fingers into contact with the high-voltage cables, thereby securing the high-voltage cables in the mounting base. The high-voltage cables are extended beyond the mounting base a distance equal to a desired spacing separating the electrical connection between the high-voltage cables and an electrical conductor associated with the mounting base. The tubular cover is transparent so that the electrical connection joining the high-voltage cables can be visually inspected through the cover.
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This application is a divisional of application Ser. No. 10/114,280, filed Apr. 3, 2002 now U.S. Pat. No. 6,626,252, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for tracking and guiding the drilling of a borehole, and more particularly to tracking a borehole being drilled generally horizontally under an obstacle such as a river, a highway, a railroad, or an airport runway, where access to the ground above the borehole is difficult or perhaps not possible.
Various well-known drilling techniques have been used in the placement of underground transmission lines, communication lines, pipelines, or the like through or beneath obstacles of various types. In order to traverse the obstacle, the borehole must be tunneled underneath the obstacle from an entry point on the Earth's surface to a desired exit point, the borehole then receiving a casing, for example, for use as a pipeline or for receiving cables for use as power transmission lines, communication lines, or the like. In the drilling of such boreholes, it is important to maintain them on a carefully controlled track following a prescribed drilling proposal, for often the borehole must remain within a right of way as it passes under the obstacle and its entry and exit points on opposite sides of the obstacle, must often be within precisely defined areas.
Prior systems, such as those illustrated in U.S. Pat. No. 4,875,014 issued to Roberts and Walters and U.S. Pat. No. 3,712,391 issued to Coyne, have provided guidance in the drilling of boreholes, but in some circumstances have presented problems to the user since they require access to the land above the path to be followed by the borehole to permit placement of surface grids or other guidance systems. Often, however, access to this land is not available; furthermore, the placement of guidance systems of this kind can be extremely time consuming, and thus expensive. The Earth's magnetic field is usually utilized for determining azimuthal direction, in such prior systems, but this creates additional problems because of the disturbances caused by nearby steel objects such as bridges, vehicular traffic and trains.
Other systems, typified by the system described in U.S. Pat. No. 4,710,708 to Rorden and Moore, provide to methods for guiding a drill in which the relative location of magnetic dipole transmitters with respect to magnetic field receivers is determined by measuring the magnetic field signals generated by the dipoles. In the system of this patent, for example, data is processed using unsynchronized clocks to derive amplitude and phase information from sinusoidally varying magnetic signals. These amplitude and relative phase signals are used to determine location and direction parameters of interest in a computational fitting procedure of successive approximation, using a gradient projection method. The application of this method to several configurations of practical interest is described in the '708 patent.
In addition, U.S. Pat. Nos. 5,485,089, 5,589,775 and 5,923,170 to Kuckes disclose methods for determining the lateral distance and orientation between substantially parallel boreholes using a solenoid powered by direct current together with an industry standard measurement while drilling (MWD) tool. U.S. Pat. No. 5,513,710 discloses a drilling guidance method for drilling boreholes under rivers and other obstacles using a direct current powered solenoid and an industry standard MWD system.
Although such prior systems are useful in various drilling guidance applications, it has been found that in many situations, increased precision and accuracy is needed.
SUMMARY OF THE INVENTION
The present invention is directed to an improved method and apparatus for providing guidance in drilling boreholes. The invention disclosed herein uses a localized electromagnetic source, which is oriented with respect to gravity, to generate magnetic fields. Vector components of this generated field are measured at a remote location with a system of sensors whose orientation with respect to the direction of gravity is known. The magnetic field measurements are analyzed mathematically to determine the azimuthal orientation of the sensors with respect to the azimuthal orientation of the source, and to determine the distance and inclination angle from the sensors to the magnetic field source.
The apparatus of the invention employs a magnetic field source that is oriented with respect to gravity and generates two mutually perpendicular, horizontal dipole magnetic fields whose polarity is periodically reversed by precise clock signals. Measuring instruments, also controlled by precise clock signals, at a remote location include three vector component alternating magnetic field sensors to measure the magnetic fields produced by the field source and three vector component gravity sensors to measure the direction of gravity relative to the measured vector components of the magnetic fields. Analysis of the magnetic field measurements gives a three dimensional sensor location with respect to the source location, and provides the azimuthal direction of the measuring instrument axes relative to the azimuthal direction of the magnetic dipole axes.
When the method of the invention is applied to drilling a borehole along a planned path, the measuring instrument package is deployed downhole, in the borehole and near the drill bit, as part of a measurement while drilling (MWD) assembly and the solenoid source is positioned at a known uphole location with respect to the planned borehole path, preferably on the Earth's surface above the path. After approximately every 10 meters of drilling, the drilling process conventionally is stopped to add a new segment of drill pipe. During this down period the required measurements and analysis required by the present invention can be carried out. This usually requires only a few minutes, during which time the solenoid source is powered in two perpendicular azimuthal orientations, the measurement data are gathered, and the measurements are analyzed. The distance and direction to the downhole instrument package and the orientation of the downhole coordinate system relative to the uphole coordinate system of the solenoid source are determined from the downhole magnetic field and gravity measurements. By comparing the measured location and orientation with the planned borehole trajectory specifications, up/down and left/right drilling direction adjustment recommendations for the next segment of drilling are provided to the driller at each measuring station. Tests at an industrial site with a system based upon the preferred embodiment disclosed herein gave useful results for drilling guidance out to a 150 meter spherical radius from the source location.
Although the invention will be described herein with respect to the drilling guidance of certain boreholes, various other applications of the disclosed method and apparatus will become apparent. For example, the system of the invention may be used in the precise determination of the paths of existing boreholes, the determination of locations in mines with reference to a surface location, or the relative location determinations which arise in tunnel construction. In certain applications, where only a few location and direction evaluations are required, enhanced range for the present system is readily provided by overnight or even longer signal averaging.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and additional objects, features and advantages of the present invention will be apparent to those of skill in the art from a consideration of the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagrammatic illustration of a drill guidance system utilizing the invention for guiding the drilling of a horizontal borehole following a proposed path to a proposed punch out point;
FIG. 2 is a diagrammatic illustration of a solenoid and turntable beacon showing provisions for setting the azimuthal orientation and for leveling the solenoid source;
FIG. 3 is a diagrammatic illustration showing the electronic circuitry configuration powering the solenoid source;
FIGS. 4A and 4B are diagrammatic illustrations showing the waveforms of the clock control signal and the solenoid current flow vs. time, respectively;
FIG. 5 is a diagrammatic illustration showing components of the alternating magnetic field and gravity measuring system;
FIGS. 6A-6C are a flow diagram of the process of the present invention for computing the distance and direction from a field source to the measuring instruments;
FIG. 7 is a diagrammatic illustration showing the relationship of vector quantities which enter into the mathematical analysis of the fields;
FIG. 8 is a diagrammatic illustration of the vector relationships between the instrument package xyz coordinate system, the downhole hsrsg coordinate system, the drilling direction which is the z axis of the instrument package, and the location vectors RSrcSens and r;
FIG. 9 is a diagrammatic illustration of the vector relationships from the source to an arbitrary point on the proposal path; and
FIG. 10 is a diagrammatic illustration showing an alternative two solenoid source which allows simultaneous generation of the two dipole magnetic fields.
DESCRIPTION OF PREFERRED EMBODIMENTS
One embodiment of the apparatus utilized in the method of the present invention in a borehole drilling application for the laying of pipeline under a river is illustrated at 10 in FIG. 1. A borehole 12 is illustrated as being drilled using an industry standard drilling motor 14 and drill rig 16 . The crossing of river 18 may entail drilling along a planned path 20 at a depth of 20 meters, for example, to a planned exit location 22 , which may be 1000 to 1500 meters away from a borehole entry point 24 . A solenoid beacon 30 is shown at a river bank 32 , which in this case is the exit side of the river, the beacon being energized to produce magnetic fields that will provide the information needed to guide the drilling at each measurement station under the river and subsequently under the earth's surface 34 as drilling progresses toward the proposed exit location 22 . The drilling motor 14 is mounted on a drill stem 36 to drive drill bit 38 , in conventional manner, with an instrument package 40 , which includes a three component accelerometer to measure the direction of gravity and a three component magnetometer to measure alternating magnetic fields, mounted on the drill stem just above the drilling motor. These instruments may or may not be part of a conventional measurement while drilling (MWD) package.
The beacon source 30 is illustrated in greater detail in FIG. 2 . In the preferred form of the invention, the beacon is positioned and oriented by land surveying techniques at a selected, known location with respect to the planned path 20 and exit location 22 . The beacon may consist of a turntable 50 upon which a solenoid 52 is mounted. The turntable is mounted on a base 54 to rotate about an axis 56 made vertical by adjusting the lengths of base support legs 58 , 60 , 62 to thereby make the solenoid 52 horizontal at all azimuthal orientations as the turntable rotates. Any convenient method, such as the use of a spirit level, may be utilized for this purpose. The turntable can be set in two orientations perpendicular to each other by a pair of pins 64 and 66 at diametrically opposite locations on the turntable that fit into two pairs of holes 68 and 70 in an orientation ring 72 mounted on base 54 . This ring can be rotated about the turntable axis 56 and clamped at any orientation by clamps 74 and 76 . After the base 54 is leveled, the orientation of ring 72 is set by loosening clamping screws 78 and 80 on clamps 74 and 76 , rotating the solenoid 52 while sighting along its axis 82 to make it point toward a surveyed reference location such as location 84 in FIG. 1, and tightening the clamp screws. The axes and the location of the beacon can thus be fixed by a simple, field-friendly procedure.
The solenoid 52 is illustrated in FIG. 3 as having a 23 kilogram laminated core 90 that, in a preferred embodiment, is 1.25 meters long. To provide the desired magnetic field, this solenoid may require 40 watts of power, for example, and this is supplied by a portable power supply such as a small, 12 volt lead acid battery 92 connected to a polarity reversing FET (field effect transistor) switch circuit 94 connected across the solenoid winding 96 . The direction of electric current flow in the solenoid winding is periodically reversed by a reference square wave with a precise cycle period of 0.5 seconds derived from clock signals 96 (FIG. 4A) generated by a crystal oscillator 98 having a frequency that is precise to a few parts per million. The solenoid current vs. time waveform illustrated at 100 in FIG. 4B produces a magnetic dipole field of alternating polarity. Although the principles of physics-governing the behavior of the magnetic fields used in the analysis to be described are those appropriate to time independent magnetic fields, it is desirable to repeatedly reverse the direction of current flow in the solenoid to allow precise separation of the solenoid field from the Earth's magnetic field and from instrumental and magnetic field noise. It is also possible to simply turn the solenoid current on and off and to record the field differences. In this case the amplitude of the alternating polarity component of the magnetic dipole and field produced will be one half that produced if the current is reversed.
A schematic diagram of the downhole measuring apparatus 40 is shown in FIG. 5 as being connected via a borehole telemetry link 110 to an uphole drilling control room 112 at the drilling rig 16 on the Earth's surface. The control room has a computer 114 for processing the data received from the downhole electronics and a controller 116 for operating the drill. A power supply 118 is connected via link 110 to power the down hole measuring instruments and telemetry circuits and to permit them to receive data from the instruments and convert the data to computer input signals. The power supply link may be a wire inside the drill stem 36 leading to the downhole instruments 40 .
The downhole instrument package 40 includes a three vector component magnetometer 120 and a three vector component accelerometer 122 , each of which generates output signals with respect to an xyz set of axes. The z axis of the instrument package 40 is aligned with the borehole 12 being drilled, and the perpendicular x and y axes have a known orientation alignment to the drill face; i.e., to the direction of a bent housing in the drilling motor which controls the direction of drilling. Direct current is received from the power supply 118 on the surface to power the instruments. The magnetometer AC outputs are passed through band pass amplifiers 124 , and are multiplexed with the magnetometer DC outputs and the accelerometer outputs at multiplexer 126 , where the signals are converted from analog to digital form and finally put into a form suitable for telemetry to the surface. The timing for digitization and telemetry is generated by a downhole clock 128 controlled by a quartz crystal whose frequency is precise to a few parts per million.
Data Acquisition and Processing
After drilling has been stopped at a measurement station along the proposed borehole path, the solenoid 52 is set to a first orientation, and energized as described with respect to FIG. 3 . The resulting reversing field with an alternating polarity component is detected by magnetometers 120 , the resulting output signals are transmitted uphole, a few minutes of data are recorded, and a data file is generated. The solenoid 52 is then set to a perpendicular orientation by rotating the turntable 90°, is energized to create a reversing field which is detected, a second set of data are recorded, and a second data file is generated. During each set of measurements the downhole multiplexer circuitry sequentially samples the output voltages of the magnetometers and the accelerometers at fixed time intervals and telemeters the results to the surface computer 114 , which separates the gravity measurements at 130 from the Earth's field measurements at 132 and the AC field measurements at 134 . The relative time at which each measurement is made is precisely preserved by the position it has in the serial data stream being telemetered, and the gravity data and AC field data are stored at data files 136 and 138 , respectively. The computer 114 generates from the gravity data a single row, three column matrix gxyz with elements gx, gy and gz, which are the representation of the measured gravity g in the xyz coordinate system. From the magnetometer measurement data, two 3-column matrices h1 and h2 are generated. The first matrix h1 has three columns h1x, h1y, and h1z which are tabulations of the time sequence of the digitized magnetometer measurement data from the first orientation of the solenoid. The second matrix h2 has three columns h2x, h2y, and h2z which are tabulations of the time sequence of magnetic field measurements from the second orientation of the solenoid.
The first step for processing the recorded magnetic field data is the generation of a reference wave form which is time synchronized with the solenoid switching circuitry 94 , as illustrated in FIGS. 6A-6C. For the apparatus disclosed herein, this time synchronization should be updated approximately once per hour; in practice it is convenient to do this at each measurement station. Signal averaging the magnetic field data matrices h1 and h2 with respect to this reference wave form produces two single row, three column matrices, H1xyz and H2xyz, of the time averaged solenoid vector magnetic field components. The first matrix has the elements H1x, H1y, and H1z, and the second has elements H2x, H2y, and H2z, which are the xy and z vector components of the two generated solenoid fields. H1xyz and H2xyz are xyz coordinate system representations of the field vectors measured.
In general, the digital signal averaging computation method applied to the measured magnetic field components has a one-to-one correspondence to a method using an analog lockin amplifier (for example an Ithaco model 3962). A lockin amplifier passes the input voltage signal through a band pass filter (functionally similar to the downhole band pass amplifiers 124 ), multiplies the filtered signal with a time synchronized reference voltage waveform and averages the resulting voltage. The time average of randomly varying noise thus processed goes to zero after a long enough time, whereas the true signal component, which is synchronized with the reference waveform, produces a DC output proportional to the desired signal component. The reference waveform which is multiplied with the signal must have good time and polarity correlation with that of the signal. The lockin amplifier incorporates circuitry to generate this reference wave form from a user-supplied input reference voltage which has periodic rising or falling edges which have precisely the same period as the signal source excitation, i.e. the same period as the square wave controlling the solenoid current. To obtain optimum time overlap correlation between the signal and reference waveform, a manual adjustment is provided to adjust the time delay between the reference voltage edges supplied and the symmetric reference waveform generated by the instrument. A good procedure for making this adjustment is to process a strong, representative signal while adjusting the time shift to maximize the averaged output. This time shift adjustment and reference input are then left fixed and the signals of interest processed.
Generation of Reference Signal and Signal Averaging
More particularly, and as illustrated in the flow diagram of FIGS. 6A-6C, the first part of the digital procedure includes generating in computer 114 a symmetric reference waveform which is time-synchronized with the uphole solenoid source 52 . As illustrated in FIG. 6A, the signals (block 140 ) detected by magnetometers 120 and accelerometers 122 and supplied to computer 114 are processed at block 142 to extract the clock signals of downhole clock 128 from the data sequence being transmitted. To determine an optimal time shift from the signals 140 at a given measuring station, the strongest signal of the six magnetic field vector components is selected and processed (block 144 ) to find an optimal time shift. For this purpose, a reference waveform is defined, against which all six magnetic field components can be signal averaged. To choose the magnetic field components with the strongest signal, the average square of the six data columns, h1x, h1y, . . . h2z, is computed, using the MATLAB function “mean” to perform the operations mean(h1.*h1) and mean(h2.*h2). From the six numbers thus found, the largest defines a column matrix of data, called hmax. The serial telemetry data stream locations assign a time to each of the measurements of hmax, and those times are put into a single column matrix called Timehmax. The functional form of the reference wave form to be used is cos(w*t), where w is the fundamental radian frequency of the source, i.e., w=2*pi/SrcPer, where SrcPer is the source period; i.e., 0.5 seconds.
Two single column reference test matrices are defined as RefTest 1 and RefTest 2 , as illustrated in FIG. 6A at block 146 :
RefTest 1 =cos( w*Timehmax ) (Eq. 1)
RefTest 2 =cos( w *( Timehmax−SrcPer /4)) (Eq. 2)
RefTest 1 is a single column matrix evaluating cos(w*t) at the times Timehmax; i.e., the times at which the measurements of hmax were made according to the downhole clock. RefTest 2 is a second cosine reference wave form evaluated at times shifted by a quarter of the time period of the solenoid clock from RefTest 1 . Passing hmax through a “digital lockin”, first with reference function RefTest 1 and then with RefTest 2 , means doing the two following evaluations
HMaxRef 1 =2*mean(RefTest 1 .* hmax ) (Eq. 3)
HMaxRef 2 =2*mean(RefTest 2 .* hmax ) (Eq. 4)
A multiplication by 2 has been included in these definitions because the average value of (Cos(w*t)){circumflex over ( )}2=½. The optimum time shift (TimeShft) indicated by these two choices of the reference functions RefTest 1 and RefTest 2 is computed (block 148 of FIG. 6 A):
TimeShft =( SrcPer /(2 *pi ))* a tan 2(HMaxRefTest 1 ,HMaxRefTest 2 ) (Eq. 5)
where a tan 2 is the MATLAB 4 quadrant inverse tangent function.
As illustrated at block 150 , all six columns of the data are now signal averaged with respect to a cos(w*t) reference function with this time shift. The 3-column measurement matrix h1 of field measurements at solenoid orientation 1, has an associated 3-column time matrix Timeh1, giving the times at which each of the measurement values of the three column matrix h1 was performed according to the downhole clock. The time shifted reference function is given and signal averaged field vector components (block 152 ) are given by:
Refh 1=cos( w *( Timeh 1 −TimeShft ) (Eq. 6)
H 1 xyz= 2*mean( Refh 1 .*h 1) (Eq. 7)
Likewise, the measurements at solenoid orientation 2 are signal averaged with the same reference function with the same time shift i.e.:
Refh 2=cos( w*Timeh 2 −TimeShft ) (Eq. 8)
H 2 xyz= 2*mean( Refh 2 .*h 2) (Eq. 9)
H1 xyz and H2 xyz , the AC magnetic field data from the two positions of the solenoid, are each one row, 3-column matrices giving signal averaged values of h1x, h1y h1z and h2x, h2y and h2z with respect to the time shifted cosine reference function. H1xyz and H2xyz are the amplitudes of the fundamental Fourier frequency component of the respective xyz vector components of h1 and h2. H1xyz and H2xyz are the representations of the magnetic field vectors H1 and H2 with respect to the xyz coordinate system defined by the instrument axes.
Use of a reference function of the form cos(w*t) in this manner gives the time projection of all the magnetic field vector component data onto a single reference function to give the signed cos(w*t) Fourier series amplitude of each vector component. This method of signal averaging does not give any relative phase information between the components which may be contained in the magnetic field measurement data.
Instead of generating time synchronization from the data, establishing direct time synchronization between the uphole and downhole clocks is sometimes the most appropriate method. This can be done by a wire or other telemetry link between the two sites. Alternatively, time signals can be derived from global positioning units or from WWV radio signals.
Magnetic Field Analysis
The notation and uphole configuration definitions for this analysis are shown in FIG. 7 . At the Earth's surface 34 , the two orientations for the solenoid 52 excitation, as illustrated by unit vectors m 1 and m 2 and these, together with the direction of the gravity unit vector g, define the surface coordinate system. RSrcSens is the vector from the origin 160 of the source coordinate system to the borehole sensors 40 near the drill bit and below the Earth's surface. The analysis begins by writing RSrcSens as a product of the magnitude of the vector R and a unit vector RUv, as follows:
RSrcSens=R*RUV (Eq. 10)
The lower case vector r is the projection of RSrcSens onto the horizontal plane of the Earth's surface, i.e., the plane of the vectors m 1 and m 2 as shown in FIG. 7 .
Rm 1 m 2 g is the representation of RSrcSens in the m 1 , m 2 and g coordinate system, as illustrated in FIG. 7, and gives:
Rm 1 m 2 g=R *(sin( AgR )*cos( Am 1 r )* m 1 +sin( AgR )*sin( Am 1 r )* m 2 +cos( AgR )* g ) (Eq. 11)
The magnetic field vectors H1 and H2 at the sensors 40 , generated by the solenoids m 1 and m 2 , have strength m Ampere m{circumflex over ( )} 2 . Maxwell's equations give the generated fields as:
H 1=( m /(4 *pi*R{circumflex over ( )} 3))*(3 *dot ( m 1 , RUv )* RUv−m 1 ) (Eq. 12)
H 2=( m /(4 *pi*R{circumflex over ( )} 3))*(3 *dot ( m 2 , RUv )* RUv−m 2 ) (Eq. 13)
The “dot” functions appearing in equations (12) and (13) return the vector dot product of its two vector arguments. There are two “azimuthal” angles Am 1 r , i.e., the angle between m 1 and r (the horizontal projection of RSrcSens onto the horizontal plane) which give the same vectors H1 and H2. They are:
Am 1 r= 0.5 *a tan 2(2 *dot ( H 1 ,H 2),( dot ( H 1 ,H 1)− dot ( H 2 ,H 2) (Eq. 14)
or
Am 1 r= 0.5 *a tan 2(2 *dot ( H 1 ,H 2),( dot ( H 1 ,H 1)− dot ( H 2 ,H 2)+ pi (Eq. 15)
Since the vector dot product of two vectors does not depend upon the coordinate system in which their representations are defined, the Am 1 r can be found from the field measurement results, i.e.,
Am 1 r= 0.5 *a tan 2(2 *dot ( H 1 xyz,H 2 xyz ),( dot ( H 1 xyz,H 1 xyz )− dot ( H 2 xyz, H 2 xyz )) (Eq. 16)
or
Am 1 r= 0.5 *a tan 2(2 *dot ( H 1 xyz,H 2 xyz ),( dot ( H 1 xyz,H 1 xyz )− dot ( H 2 xyz, H 2 xyz ))+ pi (Eq. 17)
The quantities shown in Eq. 16 and Eq. 17 are computed from the data as indicated in block 170 . The correct value of Am 1 r is chosen from a knowledge of the approximate azimuthal location of the sensor package with respect to the source location.
The horizontal unit vector in the direction of r, rUv, can be written as
rUv =cos( Am 1 r )* m 1 +sin( Am 1 r )* m 2 (Eq. 18)
The inclination angle AgR, is computed, as illustrated at block 172 , by forming the vector cross product of H1 and H2 (cross(H1,H2)) and dividing it by the total field quantity, dot(H1,H1)+dot(H2,H2) to give:
xH =cross( H 1 ,H 2)/( dot ( H 1 ,H 1)+ dot ( H 2 ,H 2)) (Eq. 19)
The vector xH lies in the plane of g and RSrcSens. To show this, compute cross (H1,H2) noting that m 1 , m 2 and g form a right handed coordinate system. When dot(cross(RrcSens,xH) is computed using Eq.(11) for RrcSens, a null result is obtained. Thus, xH must lie in the plane defined by RsrcSens, and g.
It is useful to write xH in terms of two components. The first is the projection of xH onto g and the part of xH which is perpendicular to g. Since xH is in the plane of g and R, xH can be written as sum of two vectors, one in the rUv direction and a second in the g direction:
xH=xHr+xHg*g=magxHr*rUv+xhg*g (Eq. 20)
where:
xHg=dot ( xH,g )
xHr=xH−xHg*g
magxHr=mag ( xHr ) (Eq. 21)
The MATLAB function “mag(A)” computes the magnitude of the vector A, which is sqrt(dot(A,A)). After some algebraic manipulation, the angle AgR can be written
AgR =(½)* a tan 2(6 *magxHr, 7* xHg+ 1) (Eq. 22)
Both xHg and magxHr are directly computable from the data, since the vector cross product and the vector dot product are both invariant to the coordinate systems of representation; that is:
xHxyz =cross( H 1 xyz,H 2 xyz )/( dot ( H 1 xyz,H 1 xyz )+ dot ( H 2 xyz,H 2 xyz )) (Eq. 23)
xHg=dot ( xHxyz,gxyz ) (Eq. 24)
xHrXyz=xHxyz−xHg*gxyz
magxHr=mag ( xHxyz−xHg*gxyz ) (Eq. 25)
Thus, the angle AgR is computable from the measurements as noted in block 172 .
Finally, as indicated in block 174 , the distance R between the source and the sensor locations (RsreSens) can be related to the total field strength, as follows:
R =(( m /(4 *pi )){circumflex over ( )}2*(7/2−(3/2)*cos(2 *AgR ))/( dot ( H 1 ,H 1)+ dot ( H 2 ,H 2))){circumflex over ( )}(⅙) (Eq. 26)
Again in terms of measurement representations of H1 and H2, R can be written as
R =(( m /(4 *pi )){circumflex over ( )}2*(7/2−(3/2)*cos(2 *AgR ))/( dot ( H 1 xyz,H 1 H 1 xyz )+ dot ( H 2 xyz,H 2 xyz )){circumflex over ( )}((⅙) (Eq. 27)
Thus, a systematic procedure has been disclosed to find from the measurement data the coordinate parameters of the vector RsrcSens; i.e., the distance R, the azimuth angle Am 1 r , and the inclination angle AgR.
Alternatively, the downhole coordinate system representation of RSrcSens may be called Rhsrsg, as illustrated in FIG. 8, wherein:
Rhsrsg=R *(sin( AgR )*cos( Ahsr )* hs +sin( AgR )*sin( Arsr )* rs +cos( AgR )* g ) (Eq. 28)
To determine Rhsrsg, the downhole representation parameters of RSrcSens in terms of the downhole coordinate system, it is necessary to find only the angle Ahsr, as illustrated in block 176 , since the angle AgR and R are the same in both representations. To find Ahsr (FIG. 8 ), it is useful to evaluate projections of xHr onto the hs and rs axes. To do this, the unit vector representations of hs and rs in the instrument xyz coordinate system must first be found. Since the borehole drilling direction is in the z direction, in the xyz system z=[0 0 1], it is possible to define rs and hs unit vectors as:
rs =cross( gxyz, [ 0 0 1])/ mag (cross( gxyz, [ 0 0 1]) (Eq.29)
hs =cross( rs,gxyz ) (Eq.30)
The rs unit vector is horizontal and perpendicular to the direction of drilling and points to the right side looking down the borehole. The hs unit vector is horizontal and perpendicular to both g and rs. If the borehole inclination, that is its angle with respect to gravity is less than 90 degrees then hs is on the high side of the borehole and in the plane of g and the borehole. The unit vector hs is the horizontal projection of the borehole direction.
The angle Ahsr can be found from the expression:
Ahsr=a tan 2( dot ( rs,xHrxyz ), dot ( hs,xHrxyz )) (Eq. 31)
Thus, the parameters of Rhsrsg have also been found from the measurements.
Distance and Direction to Proposed Location
The planned drilling path, or proposal, is defined with respect to surface coordinates so that the vector RsrcProp (FIG. 9) from the source location 160 to an arbitrary location 180 on the proposal path 20 is readily written in terms of the m 1 m 2 g surface coordinate system (FIG. 7 ), from the solenoid source location site 160 . The space vector from the sensor location 40 to a point 180 on the proposal RSensProp given by:
RSensProp=RSrcProp−RSrcSens (Eq. 32)
All the coordinate quantities of RSensProp in the m 1 m 2 g coordinate system representation are thus known; that is, all the quantities in the equation:
RSensPropm 1 m 2 g=RSrcPropm 1 m 2 g−Rm 1 m 2 g (Eq. 33)
are known. To guide further drilling, the vector from the sensors at the drill to a proposal point the coordinate quantities entering the down hole coordinate system representation, at sensor 40 , illustrated in FIG. 9 as the hsrsg coordinate system of RsensProp, must be known. Since both the m 1 m 2 g system of FIG. 7 and the hsrsg systems of FIG. 9 share the same g axis, the transformation from one system to the other is simply a rotation Rotm 1 m 2 gtohsrsg) about the g axis. The rotation angle is Am 1 hs =(Am 1 r −Ahsr). Thus noting that RSensPropm 1 m 2 g is a single row 3-column vector, and in MATLAB the transform of a matrix is denoted by “′” the vector may be computed, as indicated at block 182 in FIG. 6C, as follows:
RSensProphsrsg =( Rotm 1 m 2 gtohsrsg*RSensPropm 1 m 2 g ′)′ (Eq. 34)
Rotm1m2gtohsrsg
=
[
cos
(
Am
1
hs
)
sin
(
Am
1
hs
)
0
;
-
sin
(
Am
1
hs
)
cos
(
Am
1
hs
)
0
;
0
0
1
]
(
Eq
.
35
)
The parameters RSensTghsrsg in the downhole coordinate system have been all related to the measured quantities. Thus the driller can be presented with the proposal location and the direction of this proposal location with respect to the present drilling location and the direction of drilling, from which the drill bit tool face can be set to make the necessary adjustment to drilling direction.
Both the location of the downhole sensors and their relationship to the source can be determined without making use of gravity measurements. This is implied by the observation that, from the six measurements discussed above; i.e., the three vector components of H1 and the three vector components of H2, it should be possible to determine the three vector components of the source location and the three quantities specifying the relative orientation of the downhole measurement system with respect to the source. Indeed, this computation is readily carried out. However, for a given precision of the magnetic field measurements the difference in precision of the computed quantities of interest is vastly different. The greatest improvement in accuracy is obtained by determining the vertical elevation of the borehole 12 relative to the source solenoids 52 , which is of dominant interest, for the guidance of pipeline boreholes. For example, if the apparatus disclosed herein is used with the borehole sensor 40 located 10 meters below the Earth's surface at a radial distance of 100 meters from the source 52 , with the measurements of H1 and H2 having +/−1% precision, the disclosed method yields an elevation of 10+/−0.7 meters. In contrast, using a purely electromagnetic method the useless value of 10+/−30 meters is found.
Determination of the right or left direction for this case, using the method disclosed, gives an expectation error of approximately ½ degree. This precision is better than can be expected operationally using conventional Earth magnetic field measurements. Allowing +/−2 degree errors in the location determination with a signal averaging time acceptable for drilling operations, the disclosed apparatus is useful at a range of about 150 meters.
An alternative source, which generates two independent dipole fields simultaneously, is illustrated at 190 in FIG. 9, wherein similar components carry the same identifying numerals as the apparatus of FIG. 2 . Source 190 consists of two horizontal solenoids 192 and 194 mounted perpendicular to one another and supported on the turntable 50 rotatably supported by base 54 to allow the solenoid pair to be oriented with respect to a surveyed landmark. Once this apparatus is leveled and oriented at a selected source location it remains stationary until deployment at a new source location becomes necessary. The solenoids can be powered simultaneously, each by a power source similar to that shown in FIG. 3 but with different source time periods; for example, SrcPer 1 =0.4 seconds and SrcPer 2 =0.6 seconds. The data processing to evaluate the fields H1 and H2 generated in this way is similar to that disclosed above, except that only a single data file is obtained. It is first processed, as disclosed, looking for a signal with a period equal to SrcPer 1 and then a second time looking for a signal with source period equal to SrcPer 2 . Such a source beacon has important advantages; it is amenable to remote, unmanned operation and for a given measurement precision less than ½ the drill rig down-time is usually required to capture the required data.
Although the invention has been described in terms of preferred embodiments, variations and modifications may be made without departing from the true spirit and scope thereof, as set out in the following claims.
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An electromagnetic method and apparatus for directional drilling guidance of horizontal boreholes for the installation of pipelines and communication cables beneath rivers, highways and other obstacles is disclosed. A solenoid source, with horizontal axes, generates alternating electromagnetic fields which are measured in the borehole by a magnetometer with known orientation with respect to the direction of gravity near the drill bit. A preferred embodiment has a useable range of 150 meters from the source.
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RELATED APPLICATION
This complete U.S. Patent Application is related to U.S. Provisional Patent Application 60/111,326 “Electronic Display Apparatus” filed by David J. Hoch on Dec. 7, 1998.
FIELD OF THE INVENTION
This invention relates generally to devices for displaying information or images, and more particularly, to a display apparatus for producing an optical illusion of displayed images using time/position multiplexing and persistence of vision of a viewer.
BACKGROUND OF THE INVENTION
The characteristic persistence of vision of human viewers has been used to advantage in previous display devices. The Bell U.S. Pat. No. 4,470,044 uses a modulated array of lights to create momentary perceptible visual images when scanned asynchronously by the human eye. There, the display device relies on saccadic eye movement between two points of eye fixation, the device itself remains stationary.
The Nobile et al. U.S. Pat. No. 5,057,827 describes a motor actuated rotating member where an array of LEDs are turned on and off using time or position division multiplexing so that to an observer an image is generated over the path of the array.
The McEwen et al. U.S. Pat. Nos. 5,180,912 and 5,192,864 describe a linear array of LEDs that also is stationary. There, a rotating mirrored surface or facet of a polygon is used to create the effect of rotary motion of the LED array. The persistence of vision of a human observer produces a two dimensional image as the LEDs are selectively controlled.
The Belcher et al. U.S. Pat. No. 5,302,965 describes a rotating display device which rotates vertical columns of light emitting diodes. The light emitting diodes arranged in the columns sweep around a cylindrical surface. A control circuit turns the light emitting diodes on and off to provide an image display on the surface. The Belcher et al. display device requires a complex electromechanical device with a motor for rotating the LED columns at a uniform rate of rotation.
The Eason U.S. Pat. No. 5,748,157 describes a hand held wand with an LED column actuated by an inertial switch. The wand can be swung back and forth while the lights are periodically turned on and off.
The Tokimoto U.S. Pat. No. 5,548,300 also describes a manually operated wand with an array of LED lights. The wand can be swung around an operating fulcrum. The fulcrum supplies relative angular position information and rotation speed information for synchronizing the turning of the lights.
A disadvantage of traditional persistence of vision display devices is that complex electromechanical devices are required for producing uniform oscillating or rotating. The prior art devices also cannot readily adjust to different and variable periods or cycle times in different uses. The devices with a singular linear array of light are also not suited for slowly moving display systems, or for use in conditions where there is a significant amount of ambient background light.
SUMMARY OF THE INVENTION
A light display is mounted on a bicycle wheel. The display includes a plurality of arrays of lights. The arrays include at least one master array, and a number of additional slave arrays. Each of the arrays is attached to a spoke of the bicycle wheel. A sensor mounted on the wheel is actuated by a magnet mounted on the bicycle frame. The sensor is used to determine the angular velocity of the wheel. The sensor can be attached to a coil of wire where a current is induced when the coil passes through the magnetic field.
A microprocessor, mounted on the wheel and connected to the sensor, and individually connected to each array of lights by a cable, includes a memory which stores a plurality of display patterns. The microprocessor modulates the plurality of arrays of light according to a selected one of the plurality of display patterns and the sensed angular velocity of the rotating wheel to form an image using persistence of vision of a viewer.
As an advantage, the display device with multiple light arrays can be used by rotating objects having a relatively low angular velocity, such as a bicycle wheel. In addition, with multiple reinforcing lights, the device can be used in places where there is a significant level of ambient background light, such as public roads.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of linear arrays of lights mounted on spokes of a bicycle wheel;
FIG. 2 shows the array of lights mounted on a bicycle;
FIGS. 3 a - 3 f show possible light patterns;
FIG. 4 is a block diagram of master and slave light arrays;
FIG. 5 is a schematic of a master array;
FIG. 6 is a schematic of a slave array;
FIG. 7 is a side view of a bicycle wheel with one master and two slave arrays;
FIG. 8 is a partially cut-away view of a master array; and
FIG. 9 is shows arrays attached to a wheel hub.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the apparatus according to my invention comprises one or more linear arrays 101 - 103 of light-emitting diodes (LEDs), and circuitry 200 to activate the light arrays. The arrays 101 - 103 and control circuitry 200 are for mounting on spokes of a bicycle wheel 110 , either on the front, back, or both wheels. It should be understood that the apparatus can also be arranged on other rotating or oscillating objects.
At least one array 101 , and the control circuitry 200 is a “master” array, and the additional arrays 102 - 103 are “slave” arrays connected to the master by cables 105 for serial communication. Other configurations can include a single master, one master and one slave, one master and two slaves (as shown), one master and three slaves, and so forth. The light arrays are respectively mounted on master and slave housings described in greater detail below. The housings can be used to attach the arrays to moving objects, such as, wheels.
Each array includes, for example, sixteen LEDs. The number of lights can be adjusted for radii of different lengths. The control circuit 200 includes a battery compartment that holds, for example, four batteries and a microprocessor. The end of the master array nearest to the rim of the wheel includes a sensor 106 , for example, a coil including about a hundred turns of wire. A current is induced in the coil whenever it passes through a magnetic field. The current can be amplified and detected by the sensor. Alternatively, the sensor can be a reed switch, or a solid-state magnetic-field Hall-effect sensor. The sensor 106 is actuated by a magnet that can be attached to the fork of the bicycle frame. In other words, the magnet is stationary while the arrays and the sensor rotate. The sensor 106 is used to synchronize the operation of the lights as the wheel 110 rotates. The entire apparatus is operated by control buttons 108 .
As shown in FIG. 2, when a cyclist rides a bicycle 210 during low-light or night time conditions, the array 101 attached to a spoke rotate as the wheel 110 spins. When the end of an array containing the sensor 106 passes the magnet 107 on the frame, a contact closure is made. In cases where the coil is used, a current is induced, and for a Hall-effect sensor, the magnetic field is interrupted. The frequency of actuation determines the angular velocity of the wheel. With this information, the microprocessor can synchronize images and patterns displayed by the LEDs to the speed of the wheel. This allows images to be “frozen” or controllably “scrolled” in one direction or the other. Because the entire linear array of lights is swept during motion, it appears to the viewer as if the entire wheel is illuminated.
Each array contains a series of LEDs. Each LED is mounted inside a plastic housing that contains a series “light-pipes” that split the light path from the single LED into two light paths, each perpendicular to the rotation of the wheel. This is done so that the images or geometric patterns can be seen from either side of the wheel, using only a single LED. By using only a single LED and splitting the light as such, costs are reduced.
An alternative embodiment eliminates the light pipe and includes two rows of LEDs pre-mounted perpendicular to the rotation of the wheel. This configuration allows different colors to be generated on the left and right sides of the wheel by using two different colored LEDs on each side.
When a single master array 101 is used, the rider must go approximately twenty mph for the light display to appear as solid light to the human eye. At this speed, the brain “merges” the LEDs into a uniform, consistent image. To allow patterns to be viewed at slower rider velocities, additional slave arrays 102 - 103 can be spaced around the rim. Slave arrays are similar in appearance to the master array but do not contain a microprocessor and other additional circuitry. The slaves are attached to the master using cables 105 and a series of in-line connectors.
The master can determine how many slaves are attached by detecting the presence of a “pull-down-resistor” in the slaves connected to the master by cables 105 . This sensing for the number of spokes can be done when power is initially turned on. Depending on how many slave arrays are detected, the internal timings of the microprocessor can be adjusted to generate the appropriate patterns. With a larger number of slaves, the consistency, image quality and persistence to the observer is significantly better, particularly in is lighted areas.
Each slave can also include a battery compartment for additional batteries. Power available from any of the arrays can be combined to operate the apparatus. A configuration including a single master and multiple slaves can continue to operate even when a number of slaves or the master has dead batteries. Only one of the arrays needs to have good batteries, and these good batteries power the entire apparatus.
A memory connected to the microprocessor can store a large number of patterns, images, and messages, for example, hundreds. These images can be played out in a random, sequential, or fixed pattern. Selection of the playback method is done via the pushbutton switches 108 located in the master array, see FIG. 1 .
FIGS. 3 a - 3 f show additional possible patterns, for example, spokes, rings, a spiral, letters, petals, and a geometric pattern.
In the usual case, where a number of display devices are used, the display devices should be spaced as close to evenly as possible around the wheel. For bicycles, a number of arrangements for spokes exist. Many wheels have thirty-two spokes, while others have thirty-three. When attaching three display devices on a wheel with 36 spokes, for instance, each display device is placed evenly, each 120 degrees from each other, around the wheel.
When trying to attach three display devices to a 32 spoked wheel, it is impossible using mechanical connections to spokes to evenly distribute the display devices around the wheel. In this case, for a 32 spoked wheel, the display devices could be connected at 0 degrees, 123.75 degrees, and at 247.5 degrees, for example.
When displaying text and other patterns, the microprocessor must know how the display devices are distributed around the wheel. The processor executes timing experiments and adjusts the light patterns based on the separation of the display devices. If the display devices are not evenly spaced around the rim, and the microprocessor does not adjust for this, gaps and overlapping images will occur.
To prevent this, the master display device 101 can be programmed using the control buttons 108 to understand the spoke pattern on the wheel. For instance, the user might enter 32 or 36 or some other number. The user could also specifically indicate the “spoke” spacing between the devices. The microprocessor automatically determines the number of attached display devices using the pull-down resistors, this, together with the device spacing information, is sufficient information to adjust the modulation so that continuous images without gaps or overlapping are generated.
FIG. 4 is a block diagram of the circuitry 200 for one master display device 101 and three slave display devices 102 - 104 . The circuitry includes batteries 201 for powering the microprocessor 202 , memory 220 , and LEDs 230 . The slaves are equipped with programming ID resistors 240 . The number of slaves is sensed by sensing circuit 250 . The LEDs are activated via series-parallel conversion/LED drivers 260 . Power sharing among the master and the slaves is accomplished by battery share diodes 270 .
FIG. 5 is a detailed schematic of the control circuit 200 of the master display device 101 . The microprocessor 202 , e.g., a PIC16C from Microchip Technology Inc., is clocked by a 4 MHz crystal 203 . The microprocessor 202 includes memory 220 for storing the possible patterns. As shown, the two banks of eight LEDs 230 ′ and 230 ″ are driven via serial to parallel converters 231 , and the LEDs are connected to resistor networks 232 .
FIG. 6 is a detailed schematic of a slave display device, where resistor 205 is a pull-down resistor for detecting the slave.
FIG. 7 shows the master display device 101 and the two slave display devices 102 - 103 attached to the bicycle wheel 110 . In this configuration, the display devices 101 - 103 have a propeller shape.
As shown, in FIG. 8, each display device is mounted in a propeller shaped housing 800 having top and bottom part 801 - 802 . The components, for example, the LEDs 230 , microprocessor 202 and clock 203 are mounted on a circuit board 810 . The batteries 201 are mounted between the circuit board and the bottom part of the housing. The housing includes cut-outs for a series of light-pipes 820 that split the light path from the single LEDs into two light paths, each perpendicular the rotation of the wheel. The display device is attached to a spoke near the rim by a clip 807 located on the bottom part opposite the sensor 106 in the top part. As shown in FIG. 9, the other end of the display devices 101 - 103 can be attached to the hub 115 of the wheel by is elastic straps 116 .
Although the embodiments shown are for mounting on a bicycle, it should be understood that the apparatus can also be mounted on automobile wheels, ceiling fans, wiper blades, airplane propellers, or other rotating or oscillating objects.
This invention is described using specific terms and examples. It is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
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A light display is mounted on the spokes of a rotating bicycle wheel. The display includes a plurality of arrays of lights, each array attached to one of the spokes. A sensor on the wheel, actuated by a magnet mounted on the frame, senses the angular velocity of the rotating wheel with respect to the bicycle frame. A microprocessor, mounted on the wheel and connected to the sensor, and individually connected to each of the plurality of arrays of lights by a cable, includes a memory which stores a plurality of display patterns. The microprocessor modulates the plurality of arrays of light according to a selected one of the plurality of display patterns and the sensed angular velocity of the rotating wheel to form an image using persistence of vision of a viewer.
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RELATED APPLICATIONS
This application: is a continuation of co-pending U.S. patent application Ser. No. 13/218,189, filed Aug. 25, 2011, which is a continuation of U.S. patent application Ser. No. 12/364,408, filed Feb. 2, 2009, and issued as U.S. Pat. No. 8,027,785 on Sep. 27, 2011, which is a continuation of U.S. patent application Ser. No. 10/929,968, filed Aug. 30, 2004, and issued as U.S. Pat. No. 7,487,043, on Feb. 3, 2009, all of which are incorporated herein by reference in their entirety.
BACKGROUND
1.. The Field of the Invention
This invention relates to relative positioning systems, and more particularly to apparatus and methods using accelerometers to quantify changes in position.
2.. The Background Art
Scuba-diving is an exhilarating and dangerous pastime. The development of underwater breathing capability (e.g. Self-Contained Underwater Breathing Apparatus or SCUBA) has opened up a new world underneath the ocean. However, a scuba diver is venturing into an alien world for which he is ill suited. In particular, determining relative position underwater presents many challenges not present when orienting oneself on land. Both ocean water and lake water typically contain quantities of particulate matter that limit visibility. In addition, water is generally impervious to radio waves. Accordingly, visual positioning techniques and radio frequency based Global Positioning System (GPS) are not available underwater. Use of magnetic compasses likewise is made impossible by the inability to take bearings from reference points due to low visibility. Relative positioning by compass also requires an individual to evaluate how far one has traveled and in what direction. However, this approach is made impossible by underwater currents. A diver carried along by a current will have an inaccurate perception of how far he or she has actually traveled.
Determining relative position underwater is extremely critical. A scuba diver in the open ocean must be able to return to the boat or be lost at sea. A diver in a cave must be able to find his or her way out. Time is also critical, inasmuch as a diver must return to a point of origin before running out of air.
Accordingly, what is needed is a relative positioning system (RPS) enabling a diver to return to a point of origin without reliance on visual or other land-oriented guidance mechanisms. Additionally, what is needed is a system able to track a diver's movements and provide a trajectory pointing to a point of origin.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing, it is a primary object of the present invention to provide a system, method, and apparatus for determining relative position underwater. An array of accelerometers fixed with respect to one another may detect acceleration in sufficient orthogonal directions to accurately describe the movements of the array when the accelerations are doubly integrated. In some embodiments, acceleration in longitudinal, transverse, and lateral directions may be detected, as well as rotational acceleration about axes extending in the longitudinal, transverse, and lateral directions. The array may be mounted on a wrist-based computer, or be mounted to a computer secured to an article of standard scuba gear.
An electronic device, such as a small computer, may integrate the output of the accelerometers to transform the output from a representation of acceleration to a representation of velocity. Velocity integrates likewise to translation. The integrated output is then interpreted or transformed to derive a description of the current three dimensional position of the array.
A trajectory may be calculated based on a current (present) position and an objective point. The objective point may be automatically chosen to be the starting point. Alternatively, an objective point may be chosen from a series of reference points. A user may instruct the electronic device that the current position of the array is to be designated as a reference point. A diver may then move to or return to that position by setting the reference point as the objective point.
An electronic device may have a display capable of graphically representing the trajectory to a user. For example, an arrow may be displayed pointing the way to an objective point. An image of the entire trajectory may also give a user a more global view of one's circumstance. This may be toggled with a presentation of the vector in a suitable display.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and features of the present invention will become more fully apparent from the following description, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments in accordance with the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:
FIG. 1 is a perspective view of a watch-based computer hosting a relative positioning system, in accordance with the invention;
FIG. 2 is a schematic block diagram of one embodiment of a computer in accordance with the invention;
FIG. 3 is a schematic block diagram of a relative positioning system in accordance with the invention;
FIG. 4 is a schematic diagram illustrating the operation of a relative positioning system in accordance with the invention;
FIG. 5 is a schematic diagram illustrating an alternative mode of operation of a relative positioning system in accordance with the invention
FIG. 6 is an illustration of the operation of a switching module in accordance with the invention;
FIG. 7 is a process flow diagram of a method for determining relative position in accordance with the invention;
FIG. 8 is a process flow diagram of a method for determining relative position using a switching module in accordance with the invention;
FIG. 9 is a side elevation view of a ski in accordance with the invention;
FIG. 10 is a top plan view of an embedded accelerometer array in accordance with the invention;
FIG. 11 is a front elevation view of a mask having a LCD display mounted thereon in accordance with the invention; and
FIG. 12 is a process flow diagram of a method for using an embedded accelerometer array in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of systems and methods in accordance with the present invention, as represented in FIGS. 1 through 12 , is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
Referring to FIG. 1 , a relative positioning apparatus 10 for use underwater or elsewhere may include a computer 12 . The computer 12 may be wrist-mounted or be otherwise packaged to enable the computer 12 to be remain submerged and independently powered. In some embodiments, the computer 12 may be incorporated within a dive computer typically used to inform divers of critical dive parameters. The computer 12 will typically include an LCD 14 , or like display for presenting information to a user.
An apparatus 10 may track acceleration in the number of degrees of freedom (e.g. directions) necessary to track a diver's movements. In some instances these directions may include a transverse direction 16 a , a lateral direction 16 b , and a longitudinal direction 16 c . It will be noted that the directions 16 a - 16 c are defined with respect to the computer 12 . Rotational directions 18 a - 18 c , may be defined as rotation about axes parallel to the directions 16 a - 16 c , respectively. The directions 16 a - 16 c may be mutually orthogonal to one another. It will also be noted that any definition of translational and rotational directions may be used provided they are sufficient to uniquely identify the position and orientation of the computer 12 .
Referring to FIG. 2 , in some embodiments a computer 12 may include a processor 20 for executing instructions, processing inputs, and producing output data. A memory 22 may connect to the processor 20 to store executable and operational data. A memory 22 may include volatile RAM 24 as well as long term secondary memory 26 , such as flash memory or a hard drive. The computer 12 may include an input device 28 such as buttons or the like to enable a user to input user defined parameters to the computer 12 . Likewise a display 30 may enable the processor 18 to display data to a user. A display 30 may include an LCD 14 , or other video or audio output devices. A signal processor 32 may be dedicated to processing analog signals, performing such functions as filtering or making analog-to-digital conversions or vice versa.
Referring to FIG. 3 , a computer 12 may execute the modules forming a relative positioning system 31 . The modules forming the relative positioning system 31 may be formed as digital or analog circuits. Alternatively, the modules forming the relative positioning system 31 may represent computer executables (i.e. executable data) processed by the processor 20 .
A relative positioning system 31 may include a signal processing module 32 , an integration module 34 , a reconstruction module 36 , a storage module 38 , a trajectory module 40 , a reference point management module 42 , a switching module 44 , an input module 46 and an output module 48 . The input module 46 may receive user instructions directing the operation of the system 31 . For example, buttons, wireless communication links, or other data input means may be used. Likewise, an output module 48 may be a liquid crystal display (an LCD) 14 , a wireless communication link to an external device, or some other means of outputting data.
An array 50 of accelerometers may be electrically connected to a data acquisition system or other similar computer 12 , supplying information thereto relating to the accelerations experienced by the array 50 . The output of the array 50 may be input to the signal processing module 32 . The signal processing module 32 may filter the output of the array 50 to eliminate noise and otherwise condition the output to compensate for unwanted components of the output signal.
An integration module 34 may convert the output of the accelerometers from a signal representing acceleration to a signal representing velocity, displacement, or both. The integration module 32 may perform this function by numerically integrating the conditioned signal. A first integration of the signal will yield velocity whereas a second integration will yield a displacement.
A reconstruction module 36 may reconstruct a three dimensional path based on the integrated signal. An array 50 may output signals measuring acceleration corresponding to the six degrees of freedom necessary to describe the position and orientation of an object in three dimensional space (i.e. lateral, transverse, and longitudinal translation and rotation about the lateral, transverse, and longitudinal axes). Accordingly, the integrated signal may be converted by the reconstruction module 36 into a description of the acceleration, velocity, and displacement of the accelerometers in three dimensional space as well as the rotations experienced by the accelerometers.
A storage module 38 may store such things as the current three-dimensional position and orientation of the array 50 , the three dimensional position and orientation of the array 50 at a prior point in time that is significant (e.g. the starting position of the diver or one or more way points specified by the diver), or other points along the path followed by the array 50 . The storage module 38 may automatically store such points or store points as instructed by the user. For example a diver may instruct the storage module 38 that a specific point (e.g. the current position of the array 50 ) is to be saved as a way point. In some embodiments, the storage module 38 may store points based on the length of the path traveled or the amount of time that has passed (e.g. store a point every twenty feet or every 30 seconds). The length of time passed and distance traveled may be specified by a user or be either fixed or chosen automatically.
Referring to FIG. 4 , while still referring to FIG. 3 , A trajectory module 40 may compute a vector 60 indicating a trajectory of some interest for a user. It will be noted that although FIGS. 4 and 5 illustrate a two dimensional path, the trajectory may also represent a three dimensional vector. The trajectory module 40 may evaluate the current position 62 a of the array 50 and a starting point 64 stored in the storage module 38 . The trajectory module 40 may calculate a corresponding vector 60 pointing from the current position 62 a of the array 50 to the starting point 64 or another selected point of significance. As a user moves from a point 62 a to a point 62 b or 62 c , the trajectory module 40 may update the vector 60 to point from the point 62 b , 62 c to the starting point 64 as the user moves from point 62 a to points 62 b and 62 c.
Referring to FIG. 5 , while still referring to FIG. 3 , Alternatively, a user may specify that the vector 60 to be calculated shall point from a current position 62 a - 62 e to any of a number of saved way points 66 a , 66 b . In some embodiments, the trajectory module 40 may calculate a trajectory from the current position 62 to a point a standardized distance from the current position. For example, the trajectory module 40 may be programmed to constantly update the trajectory to point to a point on the reconstructed path 20 feet (or some other distance) from the current position. In this manner, the trajectory module 40 may aid a user to substantially retrace a path.
In order to facilitate precise retracing the trajectory module 40 may calculate a trajectory or a curve fit that approximates a tangent line, polynomial or other reconstructed path calculated at, near, or through the points on the path closest to the series of current positions of a user and indicating the direction to be followed to retrace the original path. That is, a path may include an original path and a return path. A user may specify to the computer 12 at some point that he is returning, thus defining subsequent additions to the path as the return path. When calculating a tangent or other curve-fit trajectory, the trajectory module 40 may use the position on the original path closest to the return path. Numerical methods and filtering may provide a shortened, smoothed, or otherwise improved return path.
A reference point management module 42 may enable a user to identify reference points that are to be stored and select which of stored reference points are to be used by the trajectory module 40 . For example, a user may press a button, or otherwise provide inputs to instruct the computer 12 , and cause that current position of the array 50 to be stored as a reference point. A user may repeatedly store points as reference points. When a user wishes to retrace a path the reference point management module 42 may present a list of reference points, e.g. reference points 66 a , 66 b , and allow a user to select which points are to be used by the trajectory module 40 to calculate a vector 60 , return path, or the like.
In some embodiments, the reference point management module 42 may automatically select which of the stored reference points 66 a , 66 b is to be used to calculate a vector 60 . For example, the reference point management module 42 may march through the reference points 66 a , 66 b , with the last reference point created used first by the trajectory module 40 . When a user approaches the location of the last reference point, the reference point management module 42 may then select the next to last reference point to calculate a new trajectory, and so on for multiple stored reference points. For example, when a user comes within a specified distance of reference point 66 a , the reference point management module 42 may automatically select reference point 66 b for use in calculating the vector 60 . In some embodiments, a reference point management module 42 may be instructed by a user, pre-programmed, or hard wired to select the reference point 66 a , 66 b , or starting point 64 based on proximity. For example at point 62 d , the reference point management module 42 may calculate that point 62 d is closer to reference point 66 b and therefore select reference point 66 b to calculate the vector 60 .
Referring to FIG. 6 , while still referring to FIG. 3 , a switching module 44 may manage interaction between the system 12 and an independent reference system 70 . An independent reference system 70 may include a global positioning system (GPS), radio frequency beacon system (e.g. OMNI), or the like. In the illustrated embodiment, cell phone towers 72 a and 72 b may be used to determine the position of a cellular phone 74 , or like device.
However, radio waves may be unavailable in some circumstances. For example, a diver will be unable to receive radio frequency signals under water. Likewise, a cell phone user who travels outside of the service coverage areas 76 a , 76 b of available cell phone towers 72 a , 72 b or is blocked therefrom will not be able to use radio contact to determine position.
Accordingly, a switching module 44 may detect when an independent reference system 70 is unavailable and prompt the other modules forming the relative positioning system 31 to function as describe hereinabove. For example, a switching module 44 may detect the weakening or disappearance of radio signals and begin tracking a user's position using the signals from the accelerometer array when the intensity of radio signals falls below a certain threshold. A switching module 44 may likewise detect when the signal intensity of an independent reference system 70 is above a certain threshold and revert to the use of the system 70 or simply re-calibrate distances for correction using the system 70 .
Referring to FIG. 7 , a method 80 for using a relative positioning system 31 may include setting 82 a reference point. Setting 82 a reference point may include storing sufficient data to define a point in three dimensional space based. Setting 82 a reference point may also include storing an orientation of the array 50 . In some embodiments, a first reference point may be presumed to be the point at which a relative positioning system 31 is first engaged or powered on. Accordingly, subsequent tracking of the movements of the array 50 will “set” 82 the reference point as simply the point of origin of the reconstructed path.
A method 80 may include conditioning 84 the output of the array 50 . Conditioning 84 may include removing noise and other artifacts from the signal output by the array 50 . Conditioning 84 the output of the array 50 may be performed prior to integration of the output and prior to reconstruction of the path. Alternatively, the integrated output or the reconstructed path may be smoothed, filtered, or both. In some embodiments, conditioning 84 may be performed by one or more of the output of the array 50 , the integrated output, and the integrated path.
A method 80 may include integrating 86 the output. Integrating 86 may include using numerical integration techniques to integrate the output signal of the array 50 . The integration 86 may be performed using analog electronics or by converting the output of the array 50 into a digital data and performing the integration programmatically or through digital logic circuits.
A method 80 may include reconstructing 88 a path followed by the array 50 . Reconstruction may include interpreting the integrated output to reconstruct the path. The integrated output may be interpreted as rotations and displacements, which may be interpreted to reconstruct a three-dimensional path followed by the array. The three dimensional path may also include a history of the rotations experienced by the array 50 . Again, the path may be smoothed to any desired degree by curve fitting.
A method 80 may include setting 90 an objective point, the objective point may be automatically set to be a starting point or first point on a reconstructed path. Alternatively, a reference point, whether created by a user or automatically, may be set 90 , whether automatically or manually, to be an objective point.
A method 80 may include calculating 92 a trajectory. Calculating 92 a trajectory may include calculating a vector pointing from the current location of the array 50 to the objective point chosen in step 90 . The vector may be displayed 94 on the LCD 14 of the computer 12 , or transmitted to another device and displayed 94 . For example, an arrow pointing to the objective point may be displayed on an LCD of a watch-based computer 12 .
Referring to FIG. 8 , a method 80 may have various alternative embodiments. In the embodiment of FIG. 8 , the method 80 is used to determine relative position in regions where independent reference systems 70 are unavailable. A method 80 may include detecting 102 signal loss. Detecting 102 signal loss may include detecting when reception of a signal is so poor as to render reliance on the signal improper. Detecting 102 signal loss 102 may include measuring the intensity of the carrier wave transmitting a signal and comparing the intensity to a predetermined value. Likewise, relative variation in signal intensity may be used in addition or instead.
The method 100 may include storing 104 the current position of the array 50 at, or near, the time when the signal loss is detected 102 . In some embodiments, the current position of the array 50 may be constantly and repeatedly stored on some schedule, such that when the signal loss is detected 102 , one or more accurate locations will be preserved. Storing 104 the current position of the array 50 may also include storing the orientation of the array 50 . The steps of conditioning 84 the output, integrating 86 the output, and reconstructing 88 a path may be performed as described hereinabove in order to track subsequent movements of the array 50 .
A method 80 may be further modified to include calculating information 106 relating to relative position and may include using the reconstructed path and the location stored in step 104 to provide information to a user relating to relative position. For example, a user's location with respect to a map of an area may be identified. Displaying 108 relative position information may include displaying to a user the information calculated in step 106 . For example, a digital representation of a map with markings indicating a user's location may be displayed. This may provide not just a vector instructing which direction to move, but perspective and context. Moreover, the vector, destination, path, or all of the above may be displayed schematically or to scale on a compass grid, Cartesian coordinate grid, polar coordinate grid, or the like.
Referring to FIG. 9 , a relative positioning system 31 may be used in conjunction with a ski 120 , snow board 120 , wristwatch, hand held device, or other type of recreational equipment, such as a surf board, skate board, bicycle, backpack, or the like. Such an integrated device will ensure that the sportsman can always return to a known point without fear of becoming lost. On land or water, a user can backtrack, beeline, or jink around obstacles, yet a relative positioning system 31 in accordance with the present invention will always indicate the correct direction toward “home” (e.g. a reference point 66 of particular interest or importance).
Additionally, a relative positioning system 31 may calculate the distance between a current position 60 and a reference point 66 . Summing or integrating in each dimension can provide net distances in two or three dimensions. Thus, one may always know the direction and distance “home” to a starting point or a destination. A relative positioning system 31 may be operative in two or three dimensions and be incorporated into sporting equipment, a wristwatch, hand held device, or the like. Additionally, a relative positioning system 31 may secure directly to, or be incorporated as an integral part of, a ski 120 , snow board 120 , bicycle, backpack, and the like for all the functionality discussed hereinabove.
Furthermore, when skiing, for example, one's weight distribution on the skis may be critical to correctly execute turns and like maneuvers. Changes in weight distribution may be accompanied by changes in the relative position of points 122 a - 122 c along the length of the ski. For example, if a skier's weight is shifted forward, the point 122 c may shift upward. In some instances, torsional flexing of the ski may also be reflective of weight distribution or otherwise important to examine a user's technique. Thus, an apparatus 10 in accordance with the invention may provide comparisons of minute variations in timing, acceleration, speed, and position for diagnostics and training.
Accordingly, a relative positioning system 31 may be used to monitor the motion of the points 122 a - 122 c . Tracking the motion of the points 122 a - 122 c may enable a user to reconstruct a model of the motion of the ski in order to give feedback to skiers regarding their weight distribution, velocity, turning technique, timing, stance, positioning and the like.
Referring to FIG. 10 , the array 50 of accelerometers may include three or more distinct arrays 130 a - 130 c . The arrays 130 a - 130 c may detect acceleration in at least one dimension. For example, the arrays 130 a and 130 c may detect acceleration corresponding to transverse acceleration only, inasmuch as upward deflection of the tip and tail of the ski may be of interest. An array 130 b may detect acceleration in all six degrees of freedom in order to provide an accurate description of the motion of the skier. In some embodiments, each array 130 a - 130 c may detect motion in multiple directions. For example, arrays 130 a , 130 c may also detect rotation in rotational direction 18 c in order to track torsion of the ski.
Arrays 130 a - 130 c may connect to serial wires 132 a - 132 c to communicate the output of the arrays 130 a - 130 c to other devices. A wire 134 , or plate may likewise connect the arrays 130 a - 130 c to another device. The wires 132 a - 132 c , 134 may be positioned between a lower layer 136 and an upper layer 138 of laminate layers forming the ski 120 . Apertures 140 , or an aperture 140 , may be formed in the upper layer 138 to enable access to the wires 132 a - 132 c . A computer 12 may secure to the ski 120 or other recreational member 120 near the apertures 140 and receive the outputs from the arrays 130 a - 130 c.
In some embodiments, the LCD 14 of the computer 12 may display data calculated by the relative positioning system 31 such as velocity, distance traveled, or the like. In some embodiments, the computer 12 may transmit the output of the arrays 130 a - 130 c , or data calculated using the arrays 130 a - 130 c to an external device using wireless communication transmitters and receivers. In some embodiments, the computer 12 may simply store the output, or the result of operations executed on the outputs, in its RAM 24 or secondary memory 26 to be retrieved later. It will be noted that the computer 12 may be positioned on the ski 120 or in some other location. The output of the arrays 130 a - 130 c may simply be stored or transmitted to a computer 12 located on the skier's person or elsewhere
Referring to FIG. 11 , in some embodiments, the output of calculations may be displayed on a mask 142 worn by a user. Using LEDs, LCDs or other display technology, a user may move a display area of a face mask, or a “heads-up” display on a part of the mask. For example, an LCD 14 may be positioned on the mask 142 . Alternatively, graphical representations of data may be projected onto the mask 142 for viewing by the user. In some embodiments, the computer 12 may also secure to the mask 142 and receive the output of the arrays 130 a - 130 c from a wireless transmitter secured to the ski 120 or from wires extending from the ski 120 to the mask 142 .
Referring to FIG. 12 , a method 80 may be modified as illustrated for use with a ski 120 . For example, the output of the array 50 , or of some step of the processing of the array output, may be transmitted 150 from the array 50 to another device. For example, the computer 12 may be remote from the array. Transmitting 150 the output may be accomplished by means of wires or wireless transmission.
Context data may be input 152 to a computer to enable interpretation of the reconstruction of the path of the array 50 . For example, a model of the ski to which the array 50 is attached may be input. Critical data 154 may be isolated from the reconstructed path. For example, the top speed or maximum altitude obtained may be determined based on the reconstructed path. In some embodiments, identifying a maximum altitude may include analyzing which maximum altitude is of significance. For example, a skier performing a jump will start at the top of a hill, descend the hill to gather speed, engage a ramp, ascend through the air until an apex is reached, and then descend. The starting position of the skier will likely be the absolute maximum, with the apex of the jump being a local maximum. Accordingly, a large parabolic portion of the path may be isolated to identify the region where the maximum altitude is to be found. Similarly, curve fitting and filtering may isolate features of interest.
The critical data isolated in step 154 may be displayed in step 156 . For example, a top speed or maximum altitude may be displayed on the top of a ski or a display secured to a skier's mask 142 . Alternatively, the critical data identified in step 154 may be stored to be displayed 156 at a later time.
In some embodiments, an animation of a rider's, boarder's, or skier's path may be rendered 158 using the context data of step 152 and the reconstructed path of the array 50 . Rendering 158 an animation may include applying translations and rotations to a digital model of a ski, bike, board, or the like. The animation may then be displayed 160 to a user in order to provide feedback to improve technique or performance.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A relative positioning system enabling a user to return to a starting position or some other point on the user's path. The system may include an array of accelerometers. The output from the accelerometers may be integrated to quantify movement of the array. The various movements of the array may be reconstructed to determine a net two or three dimensional translation. The current location of the array may be compared to a reference point to derive at trajectory directing the user to the reference point, such as an originating point. The trajectory may be continuously or periodically updated. Applications may include various displays presenting images, numbers, pointers, paths, vectors, or data by digital screens, watch faces, or other devices integrated with or remote from the processor calculating the vector back to the point of origin.
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This application claims the benefit of U.S. Provisional Application No. 60/535,373, filed Jan. 9, 2004.
FIELD OF THE INVENTION
The present invention relates generally to insecticidal compositions. In particular, it pertains to compositions of insecticides useful for control of general household pests.
BACKGROUND OF THE INVENTION
General household pests are insects that have the potential to cause nuisance or harm to person and property, such as the German cockroach, American cockroach, Smokey-Brown cockroach, Oriental cockroach, house fly, biting fly, filth fly, red imported fire ant (RIFA), odorous house ant, carpenter ant, pharaoh ant, Argentine ant, mosquito, tick, flea, sowbug, pillbug, centipede, spider, silverfish, scorpion and bed bug. The following are some examples of nuisance or harm to persons and property. Cockroaches and flies can appear in people's living environment at any place and at any time. They generally contaminate food and articles subjecting people to threats of bacteria and viruses. The continued proliferation of colonies of red imported fire ants, Solenopsis invicta , are becoming a serious problem in the United States. Fire ants are attracted to electrical circuits and can cause failures in transformers, cables, connectors and related electrical hardware. Fire ants also can sting persons or animals and generally cause a localized allergic reaction on the area of the skin punctured by their stinging. Some individuals suffer a severe allergic reaction that can lead to anaphylactic shock, which can be fatal if not treated promptly. Many of the general household pests are potentially dangerous since their bites or stings can similarly lead to allergic reaction.
Insecticidal compositions have commonly been used to control general household pests. Of primary concern in developing an insecticidal composition to control general household pests is the insecticide's ‘knockdown’ and ‘mortality’ characteristics. Knockdown refers to quick, short-term immobilization or death of the pest. Pests can recover from knockdown immobilization. Knockdown usually occurs within 10-30 minutes, but the timing is pest dependant. For example, knockdown for house flies can occur at up to 2 hours because of their tolerance for insecticides and recovery abilities. Mortality refers to death of the pest. An optimal insecticide composition would have knockdown and mortality rates at or near 100% for all general household pests. Current insecticidal compositions, for example, have red imported fire ant and German cockroach mortality rates approaching 100%, but their knockdown rates are only 80% or less for red imported fire ants and 40% or less for German cockroaches. Improved knockdown and mortality rates are desirable to ensure effective protection of persons and property from general household pests.
SUMMARY OF THE INVENTION
In accordance with the present invention, it has now been found that a new insecticidal composition significantly improves knockdown and mortality rates to general household pests. Specifically, an insecticidal composition containing a mixture of bifenthrin and acetamiprid, results in a continuous chemical barrier that provides both high knockdown and mortality rates to general household pests. Other aspects of the present invention will also be apparent.
DETAILED DESCRIPTION OF THE INVENTION
It has now been unexpectedly found that an insecticidal composition containing bifenthrin and acetamiprid, results in high knockdown and mortality rates when applied to general household pests. A preferred liquid insecticide composition of the present invention is comprised of from 0.001% by weight to 0.12% by weight of bifenthrin and from 0.001% by weight to 0.20% by weight of acetamiprid.
Another embodiment of the present invention is a method for controlling general household pests comprising applying an insecticidally effective amount of a composition comprised of bifenthrin and acetamiprid to a locus where general household pest control is needed or expected to be needed. Preferred general household pests are selected from German cockroach, American cockroach, Smokey-Brown cockroach, Oriental cockroach, house fly, biting fly, filth fly, red imported fire ant (RIFA), odorous house ant, carpenter ant, pharaoh ant, Argentine ant, mosquito, tick, flea, sowbug, pillbug, centipede, spider, silverfish, scorpion and bed bug. Preferred locus or loci are selected from a general household pest-infested structure, a structure that is expected to be general household pest-infested, or a location adjacent to the structures.
The amount of each insecticide in the composition can be varied over a wide range depending upon the target pest and the level of control desired. For controlling German cockroaches, a preferred liquid insecticide composition of the present invention is comprised of 0.001% by weight to 0.06% by weight of bifenthrin and 0.005% by weight to 0.10% by weight of acetamiprid. For controlling Red Imported Fire Ants, a preferred liquid insecticide composition of the present invention is comprised of 0.0575% by weight to 0.0625% by weight of bifenthrin and 0.025% by weight to 0.05% by weight of acetamiprid. For controlling house flies, a preferred liquid insecticide composition of the present invention is comprised of 0.001% by weight to 0.005% by weight of bifenthrin and 0.01% by weight to 0.02% by weight of acetamiprid. For controlling bed bugs, a preferred liquid insecticide composition of the present invention is comprised of 0.0575% by weight to 0.0625% by weight of bifenthrin and 0.025% by weight to 0.05% by weight of acetamiprid.
A liquid insecticide is any formulation containing an insecticide where the formulation is dispensed in an aqueous medium prior to its application to a locus where general household pest control is needed. That is to say, a liquid insecticide is made up of 1) an insecticide, 2) an aqueous medium and 3) other additives conventionally employed in insecticidal formulations (e.g. surfactants, wetting agents, freeze/thaw agents). All formulations of insecticides that are or can be dispensed in an aqueous medium prior to application are, therefore, within the scope of the present invention (e.g. Micro-emulsions, Suspension concentrates, Emulsifiable concentrates, Wettable powders, Water dispersible granules, Capsule suspensions, Emulsifiable granules or combinations thereof).
The compositions of the present invention may be derived from commercially available formulations of insecticides. For example, bifenthrin, sold by FMC Corporation under the names and trademarks of TALSTAR® GC FLOWABLE INSECTICIDE/MITICIDE, or TALSTARONE® MULTI-INSECTICIDE, to name a few, find utility in the present invention. Formulations of acetamiprid that are particularly useful in the context of the present invention include, without limitation, acetamiprid (sold under the name and trademark of INTRUDER), sold as a 70% wettable powder. Using methods known to one skilled in the art, the above-mentioned formulations of insecticides can be dispersed in an aqueous medium to provide a composition containing an insecticidally effective amount of the insecticide.
The following examples further illustrate the present invention, but, of course, should not be construed as in any way limiting its scope. The examples set forth certain biological data illustrating the efficacy of the compositions of the present invention in controlling general household pests. Each example embodies a separate test wherein the pests were randomly selected from a population at a random age. Unless otherwise indicated, all parts, percentages, and the like are by weight. The spray chambers used in the examples were approximately 73-76 inches tall, 73-83 inches long and 31-33 inches deep with an adjustable shelf (approximately 22 inches deep) and a movable spray nozzle. The spray chambers were calibrated to deliver a volume of approximately 1 gallon of liquid per 1000 square feet of area at about 14-40 pounds per square inch of pressure. A DeVilbiss hand held sprayer (Atomizer model 152) manufactured by DeVilbiss located in Glendale Heights, Ill. was used in the testing with house flies. The DeVilbiss was used to apply approximately 3-5 milliliters of product at about 10 pounds per square inch.
EXAMPLE 1
Test to Determine German Cockroach Knockdown and Mortality Rates by Applications of Combinations of Bifenthrin and Acetamiprid
The compositions of the present invention were tested for German cockroach activity in the following manner:
Test compositions made up of TALSTARONE® MULTI-INSECTICIDE and a 70% wettable powder of acetamiprid in distilled water were prepared that provided appropriate rates of application of combinations of bifenthrin and acetamiprid, as well as bifenthrin and acetamiprid alone.
The spray chamber was then calibrated to deliver the treatment solution at the desired volume and pressure over the desired area on the chamber shelf. Spray chamber shelf height was adjusted to approximately 18 inches from the spray tip. The shelf was then covered with aluminum foil and the center of the shelf from front-to-back and end-to-end was determined. A desired number of 4.0″ sieve circles were marked on the aluminum foil with a permanent marker. The inside of a desired number of PVC rings were coated with a petroleum jelly/mineral oil mixture (1:2 ratio). The PVC rings were place on the sieve circles. 10 male German cockroaches were placed inside each PVC ring. The sprayer was activated and the test compound was applied to each PVC ring interior. German cockroach knockdown and mortality were measured. The following results were recorded:
TABLE 1
Knockdown and Mortality of German Cockroach by Application
of Combinations of Bifenthrin and Acetamiprid
Knock-
Knock-
Knock-
down
down
down
Mortality
Mortality
Mortality
Rate of
Rate @
Rate @
Rate @
Rate @
Rate @
Rate @
Rate of
Appln.
10
15
30
60
120
240
Appln.
(% by
minutes
minutes
minutes
minutes
minutes
minutes
Treatment
(PPM)
weight)
(%)
(%)
(%)
(%)
(%)
(%)
A
10
0.001
0
3
23
40
—
50
50
0.005
0
0
0
38
—
60
200
0.02
0
3
45
100
100
100
600
0.06
0
8
60
100
100
100
B
50
0.005
0
13
38
53
—
63
100
0.01
0
8
38
58
—
63
250
0.025
10
35
75
88
90
83
500
0.05
8
45
88
80
98
80
B
1000
0.10
38
75
93
100
98
80
A + B
10/50
0.001/0.005
5
5
35
90
—
93
10/100
0.001/0.01
0
0
13
90
—
100
50/50
0.005/0.005
0
3
43
93
—
100
50/100
0.005/0.01
15
23
60
95
—
100
200/250
0.02/0.025
5
38
68
100
100
100
200/500
0.02/0.05
48
60
98
100
100
100
200/1000
0.02/0.10
58
90
100
100
100
100
600/250
0.06/0.025
30
53
88
100
100
100
600/500
0.06/0.05
35
63
95
100
100
100
600/1000
0.06/0.10
63
85
98
100
100
100
Untreated
0
0
0
0
0
0
0
0
A is bifenthrin, B is acetamiprid
EXAMPLE 2
Test to Determine Red Imported Fire Ant Knockdown and Mortality Rates by Applications of Combinations of Bifenthrin and Acetamiprid
The compositions of the present invention were tested for red imported fire ant activity in the following manner:
Test compositions made up of TALSTARONE® MULTI-INSECTICIDE and a 70% wettable powder of acetamiprid in distilled water were prepared that provided appropriate rates of application of combinations of bifenthrin and acetamiprid, as well as bifenthrin and acetamiprid alone.
The spray chamber was then calibrated to deliver the treatment solution at the desired volume and pressure over the desired area on the chamber shelf. Spray chamber shelf height was adjusted to approximately 18 inches from the spray tip. The shelf was then covered with aluminum foil and the center of the shelf from front-to-back and end-to-end was determined. The red imported fire ants to be treated were collected and placed in screened 16 oz paper cups. The paper cups were placed onto the aluminum foil on the spray chamber shelf. The sprayer was activated and the test compound was applied to each paper cup interior. Red imported fire ant knockdown and mortality were measured. The following results were recorded:
TABLE 2
Knockdown and Mortality of Red Imported Fire Ant by Application
of Combinations of Bifenthrin and Acetamiprid
Knock-
Knock-
Knock-
down
down
down
Mortality
Mortality
Mortality
Rate of
Rate @
Rate @
Rate @
Rate @
Rate @
Rate @
Rate of
Appln.
10
15
30
60
120
240
Appln.
(% by
minutes
minutes
minutes
minutes
minutes
minutes
Treatment
(PPM)
weight)
(%)
(%)
(%)
(%)
(%)
(%)
A
300
0.03
63
100
100
100
100
100
600
0.06
78
100
100
100
100
100
B
125
0.0125
0
0
10
5
65
90
250
0.025
10
3
5
13
98
100
500
0.05
0
15
15
60
100
100
A + B
300/125
0.03/0.0125
18
78
98
100
100
100
300/250
0.03/0.025
5
98
95
100
100
100
300/500
0.03/0.05
33
95
93
100
100
100
600/125
0.06/0.0125
45
78
100
100
100
100
600/250
0.06/0.025
65
93
100
100
100
100
600/500
0.06/0.05
100
100
100
100
100
100
Untreated
0
0
0
0
0
0
0
0
A is bifenthrin, B is acetamiprid
EXAMPLE 3
Test to Determine House Fly Knockdown and Mortality Rates by Applications of Combinations of Bifenthrin and Acetamiprid
The compositions of the present invention were tested for house fly activity in the following manner:
Test compositions made up of TALSTARONE® MULTI-INSECTICIDE and a 70% wettable powder of acetamiprid in distilled water were prepared that provided appropriate rates of application of combinations of bifenthrin and acetamiprid, as well as bifenthrin and acetamiprid alone.
A DeVilbiss hand held sprayer was used to deliver the treatment solution at the desired volume and pressure. The house flies to be treated were collected and placed in screened 16 oz paper cups. The hand held sprayer was activated and the test compound was applied to each paper cup interior. House fly knockdown and mortality were measured. The following results were recorded:
TABLE 3
Knockdown and Mortality of House Flies by Application
of Combinations of Bifenthrin and Acetamiprid
Knock-
Knock-
Knock-
Knock-
Knock-
down
down
down
down
down
Mortality
Rate of
Rate @
Rate @
Rate @
Rate @
Rate @
Rate @
Rate of
Appln.
15
30
60
120
240
1
Appln.
(% by
minutes
minutes
minutes
minutes
minutes
day
Treatment
(PPM)
weight)
(%)
(%)
(%)
(%)
(%)
(%)
A
10
0.001
0
0
19
19
48
3
50
0.005
0
19
59
63
100
63
B
100
0.01
47
47
53
41
53
16
200
0.02
69
86
72
72
78
28
A + B
10/100
0.001/0.01
67
97
100
97
100
80
10/200
0.001/0.02
66
91
97
100
100
75
50/100
0.005/0.01
26
74
100
100
100
97
50/200
0.005/0.02
66
100
100
100
100
100
Untreated
0
0
0
0
0
0
0
0
A is bifenthrin, B is acetamiprid
EXAMPLE 4
Test to Determine Bed Bug Mortality Rates by Applications of Combinations of Bifenthrin and Acetamiprid
The compositions of the present invention were tested for bed bug activity in the following manner:
Test compositions made up of TALSTARONE® MULTI-INSECTICIDE and a 70% wettable powder of acetamiprid in distilled water were prepared that provided appropriate rates of application of combinations of bifenthrin and acetamiprid, as well as bifenthrin and acetamiprid alone.
The spray chamber was then calibrated to deliver the treatment solution at the desired volume and pressure over the desired area on the chamber shelf. Spray chamber shelf height was adjusted to approximately 10.5 inches from the spray tip. The shelf was then covered with aluminum foil and the center of the shelf from front-to-back and end-to-end was determined. The bed bugs to be treated were collected and placed in screened 16 oz paper cups. The paper cups were placed onto the aluminum foil on the spray chamber shelf. The sprayer was activated and the test compound was applied to each paper cup interior. Bed bug mortality was measured. The following results were recorded:
TABLE 4
Mortality of Bed Bugs by Application of Combinations
of Bifenthrin and Acetamiprid
Rate of
Mortality
Mortality
Rate of
Appln.
Rate @ 2
Rate @ 1
Appln.
(% by
hours
day
Treatment
(PPM)
weight)
(%)
(%)
A
200
0.02
85
100
600
0.06
75
100
B
250
0.025
30
95
500
0.05
60
100
1000
0.10
95
100
A + B
200/250
0.02/0.025
90
100
200/500
0.02/0.05
95
100
200/1000
0.02/0.10
100
100
600/250
0.06/0.025
90
100
600/500
0.06/0.05
100
100
600/1000
0.06/0.10
100
100
Untreated
0
0
5
65
A is bifenthrin, B is acetamiprid
In the context of the present invention, the term “insecticide” refers to the active chemical compound or ingredient, bifenthrin and acetamiprid, which kills or causes knockdown of insects. The term “bifenthrin” means 2-methylbiphenyl-3-ylmethyl(Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate or 2-methylbiphenyl-3-ylmethyl(Z)-(1RS,3RS)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate, CAS Registry Number 82657-04-3. The term “acetamiprid” means (E)-N 1 -[(6-chloro-3-pyridyl)methyl]-N 2 -cyano-N 1 -methylacetamidine, CAS Registry Number 135410-20-7. The term “liquid insecticide” refers to a formulation of an insecticide where the formulation can be dispensed in an aqueous medium prior to its application to a locus where insect control is desired. The term “locus” refers to any locations where control of insects is needed or expected to be needed. The term “general household pest” refers to any insect or pest, such as German cockroach, American cockroach, Smokey-Brown cockroach, Oriental cockroach, house fly, biting fly, filth fly, red imported fire ant (RIFA), odorous house ant, carpenter ant, pharaoh ant, Argentine ant, mosquito, tick, flea, sowbug, pillbug, centipede, spider, silverfish, scorpion and bed bug, that cause harm or nuisance to person or property. The term “knockdown” refers to the quick, short-term immobilization or death of the insects. The term “mortality” refers to the death of the insects. The term “% by weight” refers to the weight of the insecticide or specified component as a percent of the total weight of the composition (e.g. including the aqueous medium, other insecticides, surfactants, wetting agents, freeze/thaw agents and combinations thereof).
Those of ordinary skill in the art will appreciate that variations of the invention may be used and that it is intended that the invention may be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the invention as defined by the following claims.
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The present invention relates to an insecticidal composition of bifenthrin and acetamiprid with significantly improved knockdown and mortality characteristics when applied to general household pests.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to fuel systems and vaporizing devices therein for internal combustion engines, and more particularly fuel gas generators.
(2) Description of the Prior Art
Fuel systems for internal combustion engines have generally used carburetors in which gasoline is sprayed into a stream of air and divided into a series of fine droplets approaching vaporization and conveyed to the point of combustion. Only those molecules at the surface of the gasoline droplets are in a position to react with another species and incomplete combustion results because the very short time allowed is insufficient for more than a little vaporization of the fuel to occur. The prior art engines therefore exhaust large quantities of unburned hydrocarbons, carbon monoxide and oxides of nitrogen, all of which are undesirable atmospheric pollutants. Several attempts to improve vaporization may be seen in U.S. Pat. Nos. 1,110,482; 2,585,171; 2,285,905 and 2,272,,341.
This invention simultaneously vaporizes the liquid fuel and water at high temperatures so that the fuel mixture in its heated pressurized gaseous state achieves practically complete combustion in the internal combustion engine due to the spacing of the molecules resulting from the heat and the superheated steam.
SUMMARY OF THE INVENTION
A hot fuel gas generator having a novel high temperature and pressure controlled heated vaporizer is disclosed in which gasoline and water are simultaneously vaporized to produce a hot gaseous fuel under pressure and regulated as to temperature volume and flow is in direct communication with the inlet manifold of the engine. A throttle valve and linkage controls the combustion air and a valve in the generator controls the hot fuel gas flow to the intake manifold and is actuated by the throttle valve linkage. The partial vacuum resulting from the operation of the internal combustion engine moves the combustion air with the hot gaseous fuel from the generator to the areas of combustion in the engine. The complete vaporization of the liquid fuel and the water is caused by high temperature heat from an external source under controlled pressure and volume conditions. Gasoline or other fuel in a ratio of 80% to 95% to water 5% to 20% makes a highly satisfactory hot gaseous fuel.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional side elevation of the hot fuel gas generator;
FIG. 2 is an enlarged cross sectional detail on line 2--2 of FIG. 1;
FIG. 3 is a horizontal section on line 3--3 of FIG. 1;
FIG. 4 is a back elevation of a portion of FIG. 1;
FIG. 5 is a diagrammatic illustration of a fuel system and an internal combustion engine and incorporating the generator of FIG. 1; and
FIG. 6 is a cross sectional side view of a fuel introducing fitting used in the fuel system of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
By referring to the drawings and FIG. 1 in particular, it will be seen that the hot fuel gas generator comprises a multi-chambered pressure vessel in the form of a hollow body member generally indicated by the numeral 10, the main portion of which has a heat exchange chamber 11 therein. A bottom closure 12 closes the bottom end of the heat exchange chamber 11 and a secondary hollow body member 13 is secured to the upper end of the body member 10 and a third hollow body member 14 is secured to the upper end of the secondary hollow body member 13. An upper closure 15 is affixed to the upper end of the third hollow body member 14. An integral multiple finned heat exchanger 16 is positioned in the heat exchange chamber 11 and it defines a central tubular cavity 17 surrounded by a plurality of vertically spaced integral fins 18 which extend from a location spaced with respect to the lower end of the central tubular cavity 17 to a point near the upper end thereof. The upper end of the heat exchanger 16 has a top portion 19 which is apertured as at 20 to receive a fitting 21 which in turn mounts a filter 22. By referring to FIGS. 1 and 3, it will be seen that each of the integral fins 18 has a corner thereof cut away as at 23 with the cut away corners alternating in oppositely disposed relation so that a tortuous passageway is created by establishing communication with the spaces 24 between each of the vertically spaced fins 18. The fins 18 substantially fill the heat exchanger chamber 11.
An electrically energized heating element 25 is positioned in the cavity 17 which extends vertically throughout the length of the multiple finned heat exchanger 16. The lower end of the heating element 25 extends through an aperture in the bottom closure 12 and electrical conductors 26 extend therefrom as hereinafter described.
Still referring to FIG. 1 of the drawings, it will be seen that the secondary hollow body member 13 is apertured as at 27 to receive a valve body 28 which in turn has a valve element 29 mounted therein for vertical movement. The valve element 29 which may be seen in greater detail in FIG. 2 of the drawings, has a closed bottom end and a hollow interior defining a passageway 30. The upper portion of the valve element 29 is of reduced diameter to create a chamber 31 thereabout and within the upper portion of the valve body 28. Openings 32 in the upper portion of the valve element 29 establish communication between the passageway 30 therein and the chamber 31. A vertical slot 33 is formed in the lower portion of the valve element 29 inwardly from the lower end thereof and is in communication with the vertical passageway 30, the arrangement being such that when the valve element 29 is moved downwardly from the position seen in FIG. 2, the slot 33 will begin to clear the lower end of the valve body 28 and permit flow of fuel gas from the upper end 11A of the heat exchanger chamber 11 to flow into the vertical passage 30 and outwardly through the openings 32 into the chamber 31. A secondary vertical slot 34 in the valve body 28 inwardly of the ends thereof is positioned so that when the valve element 29 has moved downwardly as hereinafter described, the chamber 31 is extended downwardly and comes into communication with the secondary vertical slot 34 whereupon gaseous fuel can flow therethrough and through an opening 35 in a partition 36 in the secondary hollow body member 13. A dual valve is thus provided.
An apertured fitting 37 in a side wall of the secondary hollow body member 13 establishes communication with a tube 38, see FIG. 1, which extends to a fitting 39, see FIG. 6, which incorporates a Venturi 40 positioned immediately adjacent in inlet manifold 41 of an internal combustion engine.
Still referring to FIGS. 1 and 2 of the drawings, it will be seen that the upper end of the valve element 29 extends vertically into a third chamber 42 defined by the third hollow body member 14 and the top closure 15 heretofore referred to and it is provided at its uppermost end with a button 43 which positions a spring 44 between the same and the upper surface of the valve body 28. The spring 44 normally biases the valve element 29 upwardly to a closed position with respect to both of the valve passageways therethrough as seen in FIG. 2 of the drawings. An arm 45 has its free end 46 positioned for sliding engagement with the upper surface of the button 43 and is attached at its other end to a shaft 47 which extends outwardly of the third hollow body member 14 and the outer end of the shaft 47 has a depending secondary arm attached thereto as seen in FIG. 4 of the drawings so that movement from the throttle linkage of the internal combustion engine as hereinafter described, imparted the secondary arm 48 by linkage 49 will actuate the valve element 29.
By referring again to FIG. 1 of the drawings, it will be seen that a pair of liquid receivers 50 and 51 are mounted in heat exchanging relation against the outer sides of the hollow body member 10. The liquid receiver 50 is apertured and provided with a fitting 52 by which water is delivered from a suitable source under a suitable pressure, for example a water tank holding two gallons more or less and a pump means for delivery the water to the liquid receiver 50 at approximately 2 PSI pressure. A U-shaped tubular fitting 53 extends from the bottom of the liquid receiver 50 to and communicates with a water delivery fitting 54 in the bottom closure 12, the inner or upper portion of which mounts a pair of vertically extending tubes 55 and 56 respectively. The tube 55 is positioned within the tube 56 and is shorter than the tube 56 so that its upper end is spaced with respect to an upper end closure 57 on the tube 56. Thus water delivered from the liquid receiver 50 through the U-shaped tubular fitting 53, flows upwardly through the tube 55 out of its upper end and downwardly inside the tube 56 and out of the lower portion thereof through an opening 58 which communicates with the lower portion of the heat exchange chamber 11. The tubes 55 and 56 are appropriately sized to provide a desirable metering action to insure the delivery of only the desirable amount of water to the hot fuel gas generator.
Still referring to FIG. 1 of the drawings, it will be seen that the liquid receiver 51 has an inlet fitting 59 in communication with the same through which gasoline or any other liquid hydrocarbon is delivered to the liquid receiver 51. A pump such as the fuel pump on a conventional automobile engine is arranged to deliver the gasoline or other liquid hydrocarbon at a pressure of substantially 8 PSI. Gasoline entering the liquid receiver 51, like the water entering the liquid receiver 50, is heated by its association with the heated hollow body member 10 and the gasoline flows from the liquid receiver 51 through a secondary U-shaped tubular fitting 60, the other end of which communicates with the lower portion of the hollow body member 10 and the heat exchange chamber 11 therein.
It will thus be seen that water and gasoline or any other liquid hydrocarbon are delivered to the bottom portion of the heat exchange chamber 11 in the hollow body member 10 of the device, and a desirable ratio has been determined to be between 5% to 20% water and 80% to 95% gasoline or other liquid hydrocarbon.
The heating element 25 which is electrically actuated as hereinbefore described, is adapted to operate at a surface temperature of between 700° F. and 800° F. and since it is intimate contact with cavity 17 in the multiple finned heat exchanger 16, the fins 18 operate at a temperature between 500° F. and 700° F. which is suitable for simultaneously vaporizing water and gasoline in the device.
A control thermostat 61 is positioned in the heat exchange chamber 11 and serves to control the operation of the heating element 25 as will be understood by those skilled in the art.
It will thus be seen that water and gasoline or another liquid hydrocarbon, such as diesel fuel, furnace oil, kerosene, or the like delivered to the bottom portion of the heat exchange chamber 11 of the device, must flow upwardly in a tortuous passageway formed by the multiple vertically spaced fins 18 which have cut away oppositely disposed corners alternately in the arrangement. During the upward flow of the water and liquid hydrocarbon, they are both vaporized and the hereinbefore mentioned advantages of wide molecular separation occurs. The hot fuel gas then flows through the aperture 20 in the top portion 19 of the multiple finned heat exchanger 16 through the filter 22 and into the upper portion 11A of the heat exchange chamber 11. It is then controlled by the valve element 29, which as hereinbefore described, is directly controlled by linkage to the throttle linkage of the internal combustion invention on which the device is installed.
In order that an automotive engine equipped with the device of the invention can be started when cold, an auxiliary vaporization device is provided and placed in communication with the heat exchange chamber 11 hereinbefore described. Still referring to FIG. 1 of the drawings, it will be seen that the auxiliary vaporization device comprises a hollow body member 61 which has a closed lower end 62 and an apertured closure 63 on its upper end. A secondary multiple finned heat exchanger 64 is positioned in the hollow body member 61 of the auxiliary vaporization device and like the multiple finned heat exchanger 16 hereinbefore described, defines a central tubular cavity 65 in which an electrically actuated heating element 66 is positioned. Electrical conductors 67 of the heating element 66 extend to a suitable power supply as hereinafter described. An inlet opening 68 is positioned in the bottom portion of the hollow body member 61 and an inlet fitting 69 is in communication therewith and is controlled by a solenoid valve or the like and it extends to a source of gasoline or other liquid hydrocarbon, such as the fuel pump of an automobile engine.
An outlet opening 70 is formed in the upper portion of the hollow body member 61 and a tube 71 establishes communication between the outlet opening 70 and an inlet opening 72 in the hollow body member 10 and in direct communication with the upper portion of the heat exchange chamber 11 and immediately below the top portion 19 of the multiple finned heat exchanger 16 therein. The opposite corners of fins 73 on the secondary heat exchanger 64 are cut away in exactly the same manner as the opposite corners are cut away at 23 in the fins 18 of the multiple finned heat exchanger 16 as illustrated in FIG. 3 of the drawings so that a tortuous passageway is formed upwardly from the bottom 62 of the auxiliary vaporization device to the upper end thereof.
The hollow body member 61 is largely filled by the secondary heat exchanger 64 and its plurality of vertically spaced fins and the remaining area holds an ounce or less of gasoline or other liquid hydrocarbon. Actuation of the heating element 66 occurs simultaneously with the actuation of the heating element 25 hereinbefore referred to as upon turning the ignition key and engaging the starter in the automobile engine equipped with the device. Substantially instantaneous vaporization of the small amount of liquid hydrocarbon in the auxiliary vaporization device formed by the hollow body member 61 occurs and the vaporized gasoline or other liquid hydrocarbon flows immediately into the upper portion of the heat exchange chamber 11 upwardly through the filter 22 and through the valve body 28 when the valve element 29 is moved responsive to movement of the throttle linkage by the accelerator peddle in the automobile. The hot vaporized gasoline flows immediately into the intake manifold 41 of the engine of the automobile and the same thereby starts instantly. Within a minute, more or less, the main heating element 25 has began producing the hereinbefore described mixture of steam and gasoline vapor which then flows by the same passageways to the internal combustion engine and suitable temperature sensors disconnect the heating element 26 of the auxiliary vaporization device.
By referring now to FIG. 5 of the drawings, it will be seen that a block diagram represents an internal combustion engine 75 having an inlet manifold 41 which extends upwardly and mounts the fitting 39 by which the hot fuel gas from the device of the invention is delivered thereto. The hot fuel gas enters the fitting 39 by the pipe 38 which communicates with the hollow body member 10 as hereinbefore described. The combustion air is controlled by a conventional throttle valve 76 which is located below an air cleaner 77, the throttle valve 76 having linkage 49 which extends to the secondary arm 48 of the hot fuel gas generator and to the accelerator pedal of the automobile in which the internal combustion engine is located. The arrangement is such that the movement of the accelerator moves the linkage 49 and simultaneously opens and closes the throttle valve 76 controlling the main combustion air and the valve element 29 in the generator which controls the hot fuel gas. In order that a desirable ratio can be established, the secondary arm 48 is provided with an adjustable connection means for the throttle linkage 49 as best seen in FIG. 4 of the drawings, and by referring thereto it will be seen that a threaded shaft 78 is mounted on brackets 79 on the secondary arm 48 and an apertured block 80 is engaged thereon. The apertured block 80 pivotally mounts a fitting 81 which is secured to the end of the throttle linkage 49. Rotation of the threaded shaft 78 will accordingly provide a desirable adjustment between the throttle linkage 49 and the valve in the generator and will provide for an idling setting, as will occur to those skilled in the art.
By referring again to FIG. 6 of the drawings, it will be seen that the hot fuel gas delivered to the fitting 39 by the pipe 38 from the generator of the invention, flows into the upper end of the inlet manifold 41 by way of circumferentially spaced apertures in the Venturi 40 in the fitting 39.
In the present disclosure the combustion air throttle valve has been referred to as being located above the fitting in which the hot fuel gas is delivered to the inlet manifold and it will occur to those skilled in the art that it can alternately be located therebelow if desired.
A modification in the means of delivering and metering the water and the gasoline or other liquid hydrocarbon to the device may be made and for example the tubes 55 and 56 hereinbefore described in FIG. 1 of the drawings as providing a metering control of the water introduced into the heat exchange chamber 11 may be dispensed with and the water delivered directly into the lower portion of the heat exchange chamber 11 by utilizing the water delivery fitting 54 as a metering device. As illustrated and hereinbefore described, the multiple fins 18 are provided with a series of registering drilled openings for the reception of the tube 56 in intimate relation to the fins 18 so that heat exchange would take place between the fins 18 and the tube 56.
A still further change may be made in the manner in which the water and the liquid fuel are delivered to the liquid receivers 50 and 51 and delivered therefrom to the heat exchange chamber 11. Direct communicating passages may be substituted for the U-shaped tubular members 53 and 60 respectively.
Those skilled in the art will observe that negative pressures existing in the inlet manifold 41 as a result of the movement of the pistons in the cylinders of the internal combustion engine 75 extend by way of the fitting 39 to the interior of the secondary hollow body member 13 so that the hot fuel gas generated by the device of the invention will move directly into the cylinders of the engine 75.
OPERATION
Operating an internal combustion engine with the device of the invention in a fuel system as described herein, requires only actuating the ignition switch and starter of the engine whereupon the heating elements 66 and 25 are energized. Simultaneously variable delivery pumps, not shown, and which may be combined in a single unit, move water and gasoline or another liquid hydrocarbon into the liquid receivers 50 and 51 and the hollow body member 61. The very small capacity of the hollow body member 61 results in the instant vaporization of the gasoline delivered thereto which then flows as hereinbefore described into the engine so that the same starts immediately even when cold. The water and gasoline or other liquid fuel being delivered to the hollow body member 10, are simultaneously vaporized as they move upwardly in the tortuous passageway formed by the vertically spaced fins 18 and the resulting hot fuel gas is made available in suitable quantities for operating the engine under all driving conditions. It will thus be seen that the hot fuel gas generator disclosed herein comprises a substantial improvement over the prior art devices in that cold start capabilities are realized and ample volume of hot fuel gas is made available and direct control of the fuel gas is linked to the throttle linkage which simultaneously controls the combustion air throttle valve of the engine.
Tests of conventional automobiles and engines equipped with the hot fuel gas generator disclosed herein show near zero levels of atmospheric pollutants in the exhaust, which eliminates the need of any catalytic converters or other devices which attempt to treat the effect and not the cause.
The tests also indicate a substantial increase in miles per gallon obtained from the hot fuel gas generated by the device of the invention as compared with the same amount of fuel supplied the same engine in the same vehicle through a conventional carburetor. For example a 1977 six-cylinder Ford Granada achieves between 38 and 45 miles per gallon of gasoline under various road conditions and loads as compared with its EPA rating of 16 to 20 miles per gallon.
The conductors 26 and 67 extend to the usual battery and/or alternator and have switches to control the energization of the heating elements 25 and 66 respectively. The switches are controlled by the ignition switch and/or temperature responsive devices in the heat exchange chamber 11. It has been determined that the device of the invention will operate with a reasonable degree of efficiency when it is supplied with only gasoline or another liquid hydrocarbon. The anti-knock qualities which are obtained through the addition of the water as aforesaid are lost and the unburned hydrocarbon emissions and carbon monoxide are increased somewhat without the additional molecular spread of the hydrocarbon which is obtained by the superheated steam in the preferred embodiment of the invention.
Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention and having thus described our invention what we claim is:
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A hot fuel gas generator for an internal combustion engine simultaneously vaporizes gasoline and water in a multi-chambered heated pressure vessel having built in regulators for controlling pressure and volume and delivers the resulting superheated steam and gaseous fuel to the intake manifold of the internal combustion engine downstream from the usual air cleaner. A single device operating at a high temperature, for example 800° F., is used for the simultaneous vaporization of the fuel and water to develop desirable working pressure and volume. The high temperature steam and gaseous fuel positions the fuel molecules at the greatest degree of separation from each other providing the greatest opportunity for contact of the oxygen, the reacting species in the gaseous condition as chemical reactions occur only between particles at the atomic or molecular level and it is necessary for the reacting species to be in actual contact at the time of reaction. The hot fuel gas produced therefore enables complete combustion and the elimination of the atmospheric pollutants common in the operation of internal combustion engines and increases the energy obtained from the fuel.
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FIELD OF THE INVENTION
This invention relates to a device for attachment to individuals traveling in darkness to identify the presence of the individual in the darkness. More particularly, the invention is particularly suited for joggers who are out jogging on public thoroughfares wherein automobiles or other vehicles travel.
BACKGROUND OF THE INVENTION
In recent years, the public has become interested in physical health activities. One of the physical health activities that has become particularly popular is jogging. Adults and children have both become interested in jogging for physical fitness and health.
Many joggers do their jogging in the early morning or late evening because of either the more preferable weather conditions or the daytime business or school conflicts. Thus, much jogging occurs in the darkness.
The combination of jogging in darkness and on public thoroughfares creates a dangerous condition. As a result, several designs have been developed to make the jogger visible to the drivers of automobiles and other vehicles traveling on thoroughfares used by joggers. Reflective tape has been provided for the garments of the jogger. The tape will identify the runner but has the disadvantage of becoming worn as the fabric is laundered. In addition, the reflection given is simply that of a stark strand of reflected tape.
Similarly, reflective vests have been provided for the runner. The reflective vests also suffer somewhat from the same laundering problem as the reflective tapes and the further fact that chaffing occurs.
Many runners desire to establish a rhythmic or steady pace as they run. Counting cadence orally or with the aid of bells or other devices attached to the runner's shoes have been tried.
SUMMARY OF THE INVENTION
The present invention is comprised of a reflector member formed with prisms to reflect light. The reflective surface is covered with a crystal or protective shield of transparent material.
In addition a clip is integrally formed with the reflector at the back surface to detachably attach the reflector to various portions of the jogger's attire. The clip is arranged to attach the reflector to a belt, running shorts, shirts of even the socks of a runner.
In addition, the reflector is provided with an opaque disc-like object to fit between the reflective surface and the inner surface of the transparent protective shield. The disc-like member can conveniently be a copper penny or a silver dime. When the runner runs, the disc (penny or dime) bounces within the reflector and provides a sound by bouncing on the inner surface of the protective shield. The sound of the bouncing disc is in cadence with the runner's gait. In one embodiment, the reflector is provided with a slot at the top of the protective shield for insertion of the penny or dime thereby making the cadence counter optional.
The bouncing opaque disc also provides a more pronounced illumination pattern since it moves across the illuminated reflecting areas in a path thereby masking the prisms immediately behind the disc on the reflecting surface to make the runner even more noticeable.
A key holder is also provided on the clip.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the reflector-cadence counter invention.
FIG. 2 is a side elevational view of the reflector shown in FIG. 1;
FIG. 3 is a top plan view of the alternative embodiment of the reflector-cadence counter wherein a slot is provided to make the cadence counter optional;
FIG. 4 is an alternative embodiment of the clip of the reflector.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The composite assembly of the applicants reflector-cadence counter 2 is shown in FIGS. 1 and 2. The reflector and cadence counter 2 consists essentially of a housing 4, a reflector surface 10 and a clip 20.
The housing 4 is circular in the preferred embodiment and includes a bezel 6 integrally formed therewith. The bezel 6 is formed on the periphery of the housing and extends forwardly therefrom to attach a crystal or transparent protective cover shield 8. The bezel 6 attaches the transparent protective shield 8 to the housing 4 in essentially sealed relationship.
The reflector surface 10 is secured to the surface of the housing 4 in conventional manner and is comprised of a plurality of reflective prisms 12 which occupy the entire reflector surface 10. The bezel 6 retains the crystal or protective cover shield 8 spaced apart from the reflector surface 10 a distance slightly greater than the width of a copper penny. The reflector surface 10 can conveniently be a standard DOT (Department of Transportation) auto or bicycle reflector.
The clip 20 is firmly secured to or integrally formed with the back of the housing 4. The clip 20 is made of either resilient plastic, spring steel or any other material which will detachably attach to a runner's belt or garment.
The reflector cadence-counter 2 also includes a keyholder hook 14 sized to allow the conventional hole found in keys to snap on the hook 14. The key holder hook 14 is provided because runners who run at odd hours often must carry a key to enable them to reenter their home after running.
As best seen in FIG. 3, a slot 16 is provided in the top of the protective cover shield 8 adjacent the bezel 6 for insertion of a hard resilient disc-like object 18. The disc-like object 18 is used to cooperate with the reflector to provide a cadence counter. A copper penny or dime, respectively now one cent and ten cents in United States of America currency, have been found in practice to be very suitable for use as the cadence counter disc 18.
The penny, dime or other opaque disc 18 acts as a cadence counter since the hard metal of the disc 18 is capable of bouncing on the inner surface of the crystal or transparent protective cover shield 8 in cadence with the runner's gait. In addition, the path taken by the disc 18 to provide cadence counting obscures the portion of the surface of the reflector 10 over which it is passing. Thus, a flickering type of reflection is given to thereby more prominently reveal the jogger to the operator of a vehicle.
The design of the reflector-cadence counter requires that the crystal or protective cover shield 8 be spaced apart from the surface of the reflector 10 a distance sufficient to allow the disc 18 to bounce without becoming stuck or obstructed. Practice has shown that by spacing the protective cover shield 8 from the surface of the reflector 10 a distance slightly greater than the width of a penny, both a penny and dime can be used as the cadence disc 18. It is also necessary that the surface of the reflector 10 and the inner surface of the protective cover shield 8 be sufficiently adhesive to avoid impairing travel of the disc 18. Conventional plastics such as transparent poly(Dmethyl-Methacrylate) or polystyrene have been found to be suitable. Further, the sealed or essentially sealed relationship required between the transparent protective shield 8 and the housing 4 or reflector 10 is only such as to avoid any openings which would allow the disc 18 to fall from the area between the reflector 10 and the transparent protective shield 8.
In an alternative embodiment, seen in FIG. 4, the clip 20a is provided with mating serrations 22 to more securely attach the reflector cadence counter 2 to the garment of the wearer whether it be shirt, running shorts, belt or socks.
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A safety reflector for a jogger is disclosed with a cavity behind the reflector surface in which a hard disk, such as a coin, is placed so that as the jogger runs the disk, as it bounces, causes a flickering pattern on the reflector and sounds cadence in accordance with the gait of the jogger.
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RELATED APPLICATION
[0001] This application, pursuant to 37 C.F.R. § 1.78(c), claims priority based on provisional application serial No. 60/333,783 filed Nov. 28, 2001.
FIELD OF THE INVENTION
[0002] This invention relates to a construction which includes a product adhered to a film laminate made-up of at least two layers, one of which is a low melting layer with a portion of the laminate extending outwardly of the product to form a flap which may be assembled with a like constructions and thereafter heat sealed to form a substantially waterproof assemblage.
BACKGROUND OF THE INVENTION
[0003] A variety of laminated constructions are required to be substantially waterproof, for instance carpet pads, under layments for wood flooring, a variety of geo-textiles for placement under landfills or at the bottom of ponds or on farms with ponds for hog sewage. In all cases, forming waterproof constructions in the field from a plurality of pieces is difficult, often resulting in less than desirable results.
BRIEF SUMMARY OF THE INVENTION
[0004] In broad terms, the present invention includes a construction and a process of making same in which a product layer has a waterproof laminate on one side thereof which extends beyond the product layer to form a flap. The product to which the laminate is adhered may be any one of a wide variety of materials including: carpet pads, floor under layment, open or closed cell foam including polyurethane, nylon weave backing for carpets, various non-woven materials and many others. The laminate adhered to the product is usually a multi-layer laminate in which there is a strengthening or substrate layer which may be made with a variety of materials including but not limited to polypropylene, polyester, polyethylene, nylons, PVC's, other vinyls and various mixtures, blends and co-polymers thereof. To this substrate layer or strengthening layer is laminated a low melting layer which may include but is not limited to ethylene vinyl acetate, polyester co-polymers, polyolefins, polyamides and various mixtures, blends and co-polymers thereof. The preferred melting point of the low melting portion of the film laminate is generally above 180° F. and preferably in the range of about between 195° F. to about 325° F. The preferred method of making the construction of the invention includes registering the product and the film laminate with the low melt layer in contact with the product and passing the registered laminate and product over a heated roller, preferably a heated drum, for a time sufficient to melt the low melt laminate to the product thereby affixing the laminate film to the product. Most importantly, a flap of the low melt material extends outwardly of the product so that when sections of the construction are mated, the overlapping flap, when heat sealed, provides a substantially moisture proof seal at the seams between adjacent constructions. This is a fundamental feature of the invention.
[0005] Other features and advantages of the present invention will be apparent to persons skilled in the art of the following detailed description of one embodiment accompanied by the attached drawing wherein identical reference numerals refer to like parts in the various views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a schematic sectional view of a laminate film heat bonded to a product showing the construction of the present invention;
[0007] [0007]FIG. 2 is a schematic representation of adjacent constructions being positioned in order to form a moisture or watertight seam.
[0008] [0008]FIG. 3 is an illustration showing the waterproofing of the seam formed in FIG. 2;
[0009] [0009]FIG. 4 is an elevational perspective view of a film laminate of the present invention showing an edge portion thereof to enlarged to illustrate the laminated construction; at the bottom of FIG. 4 is a representation of the prior art method of forming waterproof seams;
[0010] [0010]FIG. 5 is a side-elevational view of a second embodiment of the laminated film;
[0011] [0011]FIG. 6 is a side view of an apparatus for producing a composite structure of the invention; and
[0012] [0012]FIG. 7 is a detailed side view of the heated roller of the embodiment of FIG. 6.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] As illustrated in FIGS. 1 to 5 , the construction of the present invention is a combination of a film having at least one side thereof a low melt layer and a product arranged in such a way that there is a low melt flap extending from at least one end of the product which enables adjacent segments of the construction including the product to be connected in a substantially moisture proof or waterproof manner. A wide variety of constructions are available and FIG. 1 shows the placement of a laminate over a product to form a construction with a flap of approximately two inches which is later used to form a waterproof seam. The product layer may be any one of a wide variety of materials including but not limited to, carpet pads, wood floor under laminates, tile floor under laminates, closed or open cell foams such as polyurethanes, non-woven fabrics, synthetic organic resin weave backing for carpets or scrap synthetic fiber pad carpet underlayment. One significant use of the invention is in carpet padding in which adjacent sections of carpet padding need to be connected in a way so as to form a substantially water proof seam between the adjacent segments so that if a liquid is spilled on the carpeting, little if any liquid will seep through the seams of the carpet padding to pool therebelow. This is an important requirement in the carpet industry and in other industries in which under layments are required.
[0014] The film laminate may be any numbers of layers, generally two or three. There is a strengthening or substrate layer to which is either directly or indirectly attached a low melt layer. The substrate or strengthening layer can be any one of a wide variety of materials including but not limited to polypropylene, polyester, polyethylene, nylons or other polyamides, PVC's, other vinyls, substituted and unsubstituted, and various mixtures, blends and copolymers thereof; however, polypropylene is preferred. In a two layer laminate, the low melt layer is directly in contact with the substrate or strengthening layer. The low melt layer may be, but is not limited to, ethylene vinyl acetates, polyesters, polyester copolymers, polyolefins, polyamides, and various mixtures, blends and copolymers thereof; however, polyethylene is preferred. Generally, it is preferred that the low melting layer have a melting point above 180° F. but most preferably in the range of from about 195° F. to about 325° F. Temperatures somewhat lower and somewhat higher may be used without adversely effecting the construction of the present invention, but most preferably the melt temperature is about 200° F.
[0015] In some cases as illustrated in FIG. 5, there may be a three or more layer construction in which there is a primary substrate or strengthening layer of the material herein set forth followed by a co-polymer substrate which may be a combination of the strengthening or primary substrate material and a low melt material followed by a layer of the low melt material. The preferred construction is a polypropylene substrate bonded to a low melt polyethylene with a copolymer of polypropylene and polyethylene. Other more complicated constructions are entirely within the invention. In the present construction, it is imperative that a flap of low melt material extend outwardly from the product at least at one end of the construction in order to form the overlapping structures shown in FIG. 2 followed by a heating step as in FIG. 3 to provide a substantially water tight construction of the present invention. While FIG. 3 shows, for purposes of illustration only, a hand iron, other means of heating may be used.
[0016] The invention is primarily, but not restrictively, intended for use in situ or in the field, for instance, by carpet installers where the product is carpet padding or by wood floor installers where the product is hard wood or laminated wood floor under layment. In these instances, an installer's heating iron ir household iron may be used. It is important in these applications for the water tight constructions shown in FIG. 3 to be able to be produced quickly and efficiently in the field without requiring adhesives or two-way tape and without the requirement of sophisticated and expensive equipment. A hand iron is illustrated but other more sophisticated devices such as rolling heaters may also be used.
[0017] Various companies such as Dupont, D&K, Sierra and others make various laminates which are suitable for the present invention. As illustrated in FIG. 4, before the present invention, double faced tape was used between adjacent segments in order to provide a water tight seal, as well as adhesives, as taught in U.S. Pat. No. 5,952,076 issued Sep. 14, 1999 to Foster. The use of double faced tapes or adhesives in the field is messy and generally unsatisfactory whereas, the use of the present invention is far easier and more economical, and has enjoyed commercial success.
[0018] Illustrated in FIG. 6 is a heating station including a heated drum which has a length preferably somewhat greater than the width of the film and underlying product being bonded together to form the composite construction. The roller construction of FIG. 6 is better illustrated in FIG. 7 but includes an annular region made of a good heat conductor such as steel around an inner shell as seen in FIG. 7. The inner and outer shells of the drum are actually spaced apart to form an annular hollow interior region through which heated oil flows and is re-circulated from a suitable source, so as to heat the outer shell to a temperature appropriate for adhering the film to the product forming the construction. The film is positioned so that preferably the product does not touch the heated drum but the film with the low melt side facing the product is in contact with the heated drum, thereby causing the heat to pass through the laminate and melt the low melt side in contact with the product to produce the construction of the present invention. A flap is continuously produced on one or both sides by having the laminate wider than the product so that the construction is formed as illustrated in FIG. 1. A chiller (not shown) may be used if required to cool the low melt layer required. Running speeds and the temperature of the heated roller are dependant on the specific product and laminates being run, but may be determined by one of ordinary skill in the art, without undue experimentation. Although FIG. 6 illustrates a film and non-woven layer, as previously disclosed the non-woven layer may a variety of materials including but not limited to carpet or wood floor underlayment, while the film may be a strengthening layer and a low melt layer. The product layer or in FIG. 6, the non-woven layer, may be a variety of thicknesses, anywhere from {fraction (1/16)} inches to ¾ inches.
[0019] The method of the present invention is illustrated in the drawings. A two layer construction of FIG. 5 is made by registering a substrate layer or strengthening or base layer and a low melt layer with the low melt layer extending beyond the base or substrate or strengthening layer and passing these registered layers over a heated roller as shown in FIGS. 6 and 7.
[0020] A product layer may be added to the two layer construction of FIG. 5 as illustrated in FIG. 6 with the layer denoted as film being the two layer construction of FIG. 5. After heating, the three layer construction of FIG. 6 is formed with both the exterior layers being bonded directly to the low melt layer and indirectly bonded to each other. The low melt layer has at least one edge extending beyond the base or substrate layer in a two ply construction or extending beyond the base substrate layer and registered product layer in a three ply construction.
[0021] The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
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A laminate and method of making same is disclosed. The laminate includes a base layer and a low melt layer directly or indirectly bonded on one side thereof to the base layer and a product layer adhered to the other side of said low melt layer; the low melt layer extends beyond the product layer along a peripheral portion thereof. The low melt layer when in registry with an adjacent laminate and subjected to heat bonds with and forms a substantially water tight seal with the adjacent laminate. Various base, low melt and product layers are disclosed.
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This invention relates to a mounting arrangement for the advance timing piston of a distributor pump for use in the distribution of fuel to the cylinders of a diesel internal combustion engine.
A known form of distributor pump of a diesel engine commonly comprises a rotatable distributor member arranged to rotate in timed relation with the associated engine. The distributor member rotates within a sleeve including inlet and delivery ports, the distributor member including passages arranged to communicate with the ports of the sleeve in turn on rotation of the distributor member. The distributor member includes an end region arranged to rotate within a cam ring provided with a plurality of cam lobes on the inner surface thereof, the end region being provided with a plurality of radially extending bores. A plunger is provided in each of the bores and arranged to perform reciprocating motion, the outer end of each plunger being provided with a shoe housing a roller arranged to engage with the cam lobes of the cam ring on rotation of the distributor member.
In use, fuel is supplied to the inlet port, and from there to the bores of the distributor member when the inlet port aligns with a corresponding passage of the distributor member. Rotation of the distributor member cuts off the communication with the inlet port and in turn results in the rollers engaging with the cam lobes pushing the plungers into the bores and pumping fuel from the distributor member through a delivery port which by that stage has come into alignment with a corresponding passage of the distributor member.
The distributor member, sleeve and cam ring are located within a housing which includes a bore or passage extending transverse to the axis of the distributor member and cam ring, a fluid pressure operable advance piston being provided within the bore. In order to adjust the time at which fuel is delivered to the cylinders of the engine, the cam ring is angularly adjustable, movement of the cam ring occurring as a result of the engagement of a peg secured to the cam ring with the advance piston. When a change in the timing is desired, the fluid pressure applied to the piston is varied and the movement of the piston is transmitted to the cam ring. Such movement adjusts the position of the cam lobes, and hence the time at which the rollers come into engagement with the cam lobes to effect inward movement of the plungers.
In another form of distributor pump, the rotary distributor member is also axially movable and forms the pumping element of the pump. The distributor member is provided with a face cam having cam lobes which cooperate with rollers to move the distributor member in the pumping direction the return motion being effected by a spring. The rollers are mounted in a cage which is angularly adjustable about the axis of rotation of the distributor member for the purpose of varying the timing of fuel delivery. The angular setting of the cage is determined by an advance piston.
The pumps are commonly provided with a non-ferrous housing, for example an aluminium housing, and one disadvantage with such a pump if the bore is machined in the housing is the possibility of excessive leakage of fluid due to wear of the bore and due to the differences in the thermal expansivities of the housing and the advance piston. Excessive leakage results in impaired performance.
OBJECTS AND SUMMARY
According to the present invention there is provided a mounting for an advance piston wherein the advance piston is provided in a sleeve provided with outwardly extending flanges for securing the sleeve to the housing of a pump.
One of the flanges may be integral with the sleeve, the other flange being arranged to be secured thereto, the sleeve and the non-integral flange preferably being provided with screw threaded regions arranged to engage with one another to secure the flange to the sleeve.
Alternatively, both of the flanges may be securable to the sleeve, the flanges being provided with apertures for the reception of bolts engageable within threaded holes in the pump housing.
The invention will further be described, by way of example, with reference to the accompanying drawings in which like reference numerals denote like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a distributor pump including a mounting arrangement according to a first embodiment of the invention;
FIG. 2 is a cross-sectional view of part of a distributor pump of FIG. 1; and
FIGS. 3 to 7 are views similar to FIG. 2 of second, third, fourth, fifth and sixth embodiments.
DESCRIPTION
Referring to FIG. 1, the pump comprises a body part 1 in which is mounted a rotary cylindrical distributor member 2 having formed at one end a head 3 mounting in a bore, a pair of reciprocable pumping plungers 9. The pumping plungers 9 are arranged to be moved inwardly as the distributor member is rotated by the action of a plurality of cam lobes projecting inwardly of the internal peripheral surface of an annular cam ring 15 which surrounds the distributor member. Also formed in the distributor member is a longitudinal bore 10 which at one point is in communication with an outwardly extending delivery passage 17 which is arranged to register in turn, as the distributor member rotates, with a plurality of outlet ports 18 which in use are connected to injection nozzles respectively mounted on the associated engine.
At another point the longitudinal passage is in communication with a plurality of equi-angularly disposed and radially extending inlet passages 11 which register in turn, as the distributor member rotates, with an inlet port 12 formed in the body part. The communication between an inlet passage 11 and an inlet port 12 occurs during the time when the plungers 9 are permitted to move outwardly by the cam lobes and the communication of the delivery passage 17 with one of the outlet ports 18 occurs prior to inward movement of the plungers by the action of the cam lobes. It will be noted that the plungers 9 at their outer ends engage shoes which carry rollers the axes of the rollers being disposed parallel to the axis of rotation of the distributor member.
At the opposite end of the distributor member to the bore which accommodates the plungers, is mounted the rotor of a vane type feed pump 5 having an inlet 6 and an outlet 7 in the body part. The inlet 6 of the feed pump in use is connected to a source of liquid fuel and the inlet and outlet are interconnected by way of a valve 8 which controls the output pressure of the feed pump in such a manner that it varies in accordance with the speed at which the apparatus is driven. Since the distributor member is driven by the engine the output pressure of the feed pump is also dependent upon the speed of the engine and the outlet of the feed pump is in communication with aforesaid inlet port 12 by way of an adjustable throttle valve 14 whereby the quantity of fuel which flows through the inlet port 12 whilst the plungers are capable of moving outwardly can be varied. The throttle valve consists of an angularly adjustable cylindrical member the setting of which is controlled by a speed responsive governor (not shown). The cam ring 15 is angularly adjustable within the body part for the purpose of varying the timing of delivery of fuel to the engine. The cam ring is connected to a fluid pressure operable piston 19 which is mounted within a sleeve 22 located within a cylindrical bore 20 which is tangentially disposed relative to the cam ring 15. The piston 19 is loaded by a coiled compression spring 44 towards the retarded position and a passage 40 connects the outlet 7 of the feed pump with the bore 20 so that the position of the piston 19 is dependent upon the outlet pressure of the pump.
The sleeve 22 illustrated in FIG. 2 comprises a steel tube 24 one end of which is closed by an integral flange 26 which extends radially outwardly of the tube 24 in addition to closing the end thereof. The flange 26 is of hexagonal cross section, one of the flat sides of the flange 26 being arranged to engage with a raised portion 28 of the housing in order to locate the sleeve 22 correctly. The open end of the tube 24 is provided with an externally screw threaded region which protrudes from the housing. An internally screw threaded nut 30 is arranged to engage with the screw threaded region of the tube 24, the nut 30 extending radially outwardly of the bore. In order to facilitate fastening the nut 30 to the tube 24, the nut 30 is provided with a region of hexagonal cross-section arranged to be engaged by a spanner or other suitable tool.
The centre portion of the tube 24 is provided with an opening through which the peg 34 of the cam ring 15 extends, in use.
The tube 24 houses the advance piston 19 which includes a recess 32 within which the peg 34 is arranged to engage. The tube 24 is provided with an aperture 38 between the advance piston 19 and the integral flange 26, the aperture 38 communicating with a passage 40 provided in the housing for carrying fuel under pressure from the outlet 7 of the feed pump 5 to the sleeve 22 in order to move the piston 19 to adjust the position of the cam ring 15. The end of the advance piston 19 remote from the integral flange 26 of the sleeve 22 is provided with an axially extending cylindrical bore 42 housing an end of a return spring 44, the other end of the spring 44 bearing against an inwardly extending flange of a hollow cylindrical member 46 which in turn bears against the inner surface of the nut 30. The part of the sleeve 22 housing the spring 44 is arranged to communicate with a part of the interior of the housing at low fuel pressure.
Since the pressure of fuel in the passage 40 is dependent upon the speed of operation of the feed pump 5, and hence upon the speed of the engine, an increase in engine speed results in the application of high pressure fuel to the piston through the aperture 38 pushing the advance piston 19 to the left as shown in FIG. 2. Such movement adjusts the position of the cam ring 15 advancing the timing of fuel delivery to the engine, and in addition compresses the spring 44. Movement of the piston 19 to the left is restricted by the end of the piston 19 engaging with the cylindrical member 46.
On reducing engine speed, the pressure in the passage 40 reduces, the piston 19 moving to the right under the action of the spring moving the cam ring in an anticlockwise direction retarding the timing of fuel delivery to the engine.
Suitable seals 48 are provided in order to prevent leakage of fuel from the pump between the sleeve 22 and the housing, and a sealant 50 is applied to seal the nut 30 to housing.
The embodiment illustrated in FIG. 3 is similar to that illustrated in FIG. 2, the aperture 38 for applying fuel to the advance piston 19 being replaced by an annular passage 52 between the housing and the tube 24, and a port 54 which is arranged to supply the fuel to a shock valve 56 provided within the advance piston 19. It will be recognised that in use, when the rollers come into contact with the cam lobes 26, a large force is applied to the cam ring 15 which tends to move the cam ring 15 in an anticlockwise direction, this being the direction of rotation of the distributor member. The shock valve 56 is, in effect, a non-return valve which closes on the application of very high pressure to the piston 19 such as occurs when the rollers contact the cam lobes 26, substantially preventing movement of the piston 19 to the right. A small drain 58 is provided in parallel with the shock valve 56 which together with leakage, allows fuel to flow from the cylinder containing the piston when the fuel pressure falls. With a fall in the fuel pressure the piston moves towards the right under the action of the spring 44.
The sleeves illustrated in FIGS. 4, 5 and 7 each comprises a steel tube 60, the ends of which are closed, in use, by a pair of steel discs or rectangular plates 62, 64 each of which includes a plurality of apertures for the reception of bolts 66 engageable within threaded holes in the housing. The discs 62, 64 therefore engage the ends of the tube 60 and being larger than the bore of the housing, prevent the tube 60, when assembled, from leaving the bore.
In the embodiments of FIGS. 5 and 7, dowels or pins 70 are provided to align the tube 60 with the disc(s) 62, 64 in order to ensure that the tube 60 is positioned correctly with the opening 72 aligned with the opening of the housing permitting the peg 34 of the cam ring 15 to engage with the advance piston 19.
In each of the embodiments, suitable seals 48 are provided in order to prevent leakage of fuel from the pump.
FIG. 6 shows an embodiment in which the sleeve 22 comprises a tube 74 provided with an outwardly extending flange 76 at an end thereof arranged to engage with the outer surface of the housing, the tube 74 being closed, in use, by a steel disc 78. The other end of the bore is closed by a second steel disc 80, a hollow cylindrical member 82 having one end closed by an integral wall being held captive within the bore by the second disc 80. If desired, the disc 80 and member 82 may be integral with one another. In order to secure the sleeve 22 in position, the steel discs 78, 80 and the outwardly extending flange 76 are provided with a plurality of apertures for the reception of bolts 84 engaged within threaded holes in the housing.
A helical spring is arranged to return the advance piston 19 to the right as in the other embodiments.
Each of the embodiments illustrated in FIGS. 4 to 7 include the shock valve 56 and drain 58 of the second embodiment. If desired, the valve 56 and drain 58 may be omitted, or replaced by a similar valve provided in the passage of the housing carrying fuel from the housing to the sleeve, and such a valve 56 and drain 58 may be included in the embodiment of FIG. 2.
In each of the embodiments, the sleeve 22 and advance piston 19 are both constructed of steel or another ferrous material. If the piston 19 and sleeve 22 are subjected to similar temperature increases, the thermal expansion which occurs does not significantly increase the clearance between the piston 19 and the sleeve 22 due to the piston 19 and sleeve 22 having substantially equal thermal expansion rates. It will be understood that by maintaining a substantially constant clearance with varying temperature results in a reduction in the quantity of fuel escaping between the piston 19 and sleeve 22. Further, by using materials of similar hardness, less wear occurs due to the sliding movement than occurs in the conventional arrangements.
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A mounting for an advance piston comprises a sleeve having flanges arranged to extend outwardly and arranged to engage a pump housing in order to secure the sleeve thereto, the sleeve extending within a passage provided in the pump housing. One or more of the flanges may be securable to the sleeve for example, by screw threaded engagement, or by means of bolts.
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BACKGROUND OF THE INVENTION
The present invention relates to woollen type yarn spinning and particularly a mechanical system and a process wherein the same is employed for continuous working woollen type yarns between the finisher card and spinning frame.
It is well known by the skilled in the art that in a spinning process of woollen type yarns, after the carding operation through two or more sets, a number of bands are split from the sheet or web of fibers by a "condensor", which pass the bonds on leather tapes to a series of double leather endless belts or "rubbers", and the reciprocating movement of these, rubs and compresses the fibers of each band into narrow, round untwisted slivers or slubbings (i.e. having a false or "mock" torsion) which are wound on to elongated spools to be generally mounted as coaxial spool pairs on a spinning frame, being ready to feed a section of same for the final spinning.
In most cases such slubbings are arranged as four coaxial and side-by-side elongated spools, and the "mock" torsion thereof is provided by the rubbing and compressing action of said double leather endless belts during the reciprocating movement of same.
When the winding phase of slubbings on to elongated spools through the condensor is completed, these elongated spools are collected and carried to the spinning frames to continue the spinning process as final spinning of the woollen yarn as desired.
Where prior art of woollen spinning is followed the result is a forced interruption in the process. The phases of the interruption are: (a) forming elongated spool of woollen slubbing through the condensers of prior art, which are provided with mechanical means for said purposes; (b) unloading said elongated spools and collecting same waiting for the next use on a spinning frame; and (c) carrying said elongated spools both for collection and loading of same on the spinning frames. The interruption results in a loss of time which is by-itself not indifferent, but also a consequently higher manufacturing cost.
SUMMARY OF THE INVENTION
A main object of the present invention is to eliminate these additional working phases by installation of a new mechanical system between the finisher card and spinning frame, which allows a continuous operation also from the one to other of these machines.
Another object of the present invention is to transfer, through a suitable belt conveyor, the card web or sheet of fibers up to the condenser head which, while being of a conventional type, operates only to split the entire width of a card web being transferred from the card doffer comb to the condenser head through said belt conveyor, in a number of bands arranged side-by-side, this number of bands being selected so that the total number of same be correspondent to the total number of spindles in the spinning frames employed for spinning woollen yarns as desired.
A further object of the present invention is to allow said fiber bands to be carried after the splitting operation, up to a pair of rolls which are driven for a rotating movement about their axes as well as a reciprocating motion along the same, but in opposite directions from one to the other roll in a roll pair, so that a rubbing action is applied to the split band placed therebetween and a slubbing having a "mock" or false torsion is produced which will be passed on to the draft roll head of the correspondent spinning frame for a final spinning.
A still further object of the present invention is to use for the spinning, not a single spinning frame only the spindle number of which is equal to the total split bands delivered by the condenser, i.e. equal to the slubbings obtained as above, but rather a set of spinning frames, each one having a partial number of spindles and being supplied with a correspondent number of slubbings delivered by the condenser after the rubbing action.
Another object of the present invention is to provide such a set of rubbing roll pairs for each one of the stated spinning frames, these roll rubbers being mounted and operated so that a single roll rubbing pair is substantially above the draft roll head of the correspondent spindle and the slubbing is fed evenly through a free falling thereof.
A further object of the present invention is to provide for the suitable synchronism between the carding set members, from the inlet to the outlet end of the set, the set of spinning frames wherein the slubbings being delivered from the condenser head and rubbers are worked, and further between all the operating members of said machines for carding, splitting, rubbing and final spinning.
DESCRIPTION OF THE DRAWINGS
Advantages resulting from the application of this new mechanical system and related working process will be evident to the skilled in the art. Some other features and object of the invention will however become apparent as the description of an exemplifying embodiment progresses, wherein the use of ring spinning frames is provided for the final spinning, with reference to the accompanying drawings in which:
FIG. 1 is a schematic side elevation view of the working member unit between a finisher card and a spinning frame set, wherein the mechanical system of conveying, "condenser" and rubbing rolls to form a slubbing in accordance with the present invention are provided, so that a continuous working of woollen type yarn may be performed.
FIG. 2 is a schematic enlarged top view of the working member unit as in FIG. 1, but relating to the central part only of the condenser head and corresponding sections of spinning frames which are provided at both sides of said condenser head.
FIG. 3 is a partial schematic elevation view, taken along line 3--3 of FIG. 1.
FIG. 4 is a schematic side elevation view of a modified arrangement between finisher card doffer and belt conveyor to supply a card web on to the condenser head.
FIG. 5 is a schematic side elevation view of another embodiment for continuous working between finisher card and condenser, the card web being supplied to the taker-in rolls of the condenser directly, by gravity feed.
DETAILED DESCRIPTION
Referring now to the drawings and first to FIGS. 1 and 2, the skilled in the art may have therethrough, while in a schematic form, the basic conception of the mechanical system in accordance with the present invention to perform a continuous working of woollen type yarn from the finisher card to the spinning frames. To clearly describe such a concept as well as for the correspondent illustrations, an example of mechanical system was selected in which the condenser head serves to supply a set of eight ring spinning frames, each one having a reduced number of spindles, and particularly four ring spinning frames the spindles of which are provided at both sides thereof.
From card doffer 10 of a conventional finisher card, a doffer comb 11 allows the doffed web or sheet of fibers 12 be passed on the upper run of belt conveyor 14, the motion of which is directed as shown by the arrows in FIG. 1. Belt conveyor 14 is suitably guided by means of guide rolls 15, and the guide rolls which are shown at the right end in FIG. 1 allows a free falling of the card web between the take-in rolls 16, 16' of condenser head 17. The width of belt conveyer 14, as well as the length of take-in rolls and condenser head 17 corresponds to the width of card doffer 10 and more particularly to the width of doffed card web 12.
The main rolls of condenser 17 are indicated in 18 and 18', as a pair of rolls to perform the splitting operation of the card web into a desired number of bands which are arranged side-by-side in the predetermined sequence being suitable for feeding into said eight sides of ring spinning frames. The related slubbings having a false torsion will then be spun as desired.
While condenser head 17 could be considered of a conventional type, in accordance with the present invention it is arranged and operates in somewhat different manner, to attain the desired aim of a continuous working. For this purpose it is located in the middle of spinning frames to be supplied, at a level which is above the highest spinning frame height. Roll pairs 16, 16' - 19, 19' and 20, 20' are to be considered as guide rolls, the first pair 16, 16 being the take-in rolls of card web, 19, 19' being the guide rolls for the correspondent narrow belts of the condenser, and 20, 20' being the guide rolls to doff split bands 12' which are directed to the left-hand and right-hand, respectively, as in FIG. 1.
For these split bands the motion of which is toward the left-hand and right-hand other guides 21, 22, respectively, are also provided, which are here shown as short belt-conveyers, while rolls 23, 24, 25, 26 and 23', 24', 25', 26' comprise the so-called lap plate conveyors to cooperate in taking-in the split bands between roll rubbing pairs 27,28-29,30-31,32-33,34 relating to the four spinning frame heads at the left-hand in FIG. 1 and 27', 28'-29',30'-31',32'-33',34', respectively, relating to the four spinning frame heads at the right-hand.
Employment of rubbing rolls or cylinders as a substitute for short double leather endless belt is not by-itself a novelty for condenser in woollen type yarn working. Two particular features are, however, to be pointed out in the present invention, namely: (1) arrangement of a single pair of rubbing rolls for each spinning frame to be fed, the position of which is remote from the condenser head; (2) employment of rubbing rolls which are provided with a synthetic material coating 40 upon the elongated sections of driven metal cylinders, which are similar to drafting rollers of some spinning machines. On the ground of practical experiments it was further found that a nylon coating is very suitable for an effective rubbing action in order to provide slubbings with false torsion to be supplied on to spinning frames for final spinning operation. This may be due to friction upon the slubbing, such a rubbing action being assisted by a self-lubrication which is very helpful for operative purposes.
In order to describe and illustrate the present invention, four double sided spinning frames only were assumed, the number of spindles in each side being reduced so as to spin slubbings 35 supplied from the rubbing roll pairs which are operating on bands 12' of the split card web 12 through condenser head 17. Conventional ring spinning frames 36, 37, 38, 39 were assumed, which are characterized only by the reduced number of spindles and spindle gauge, this letter substantially equal to the gauge slubbing 35 as formed respective bands 12' after said splitting operation through condenser 17.
Through the schematic illustration in FIG. 1 it should be apparent to the skilled in the art that the mechanical system and continuous working process from the finisher card to the spinning frames, in accordance with the present invention, are shown in the section of that FIG. 1 which is above spinning frames 36, 37, 38, 39. This mechanical system generally comprises a belt conveyor 14, condenser 17, rolls 23, 24, 25, 26 and 23', 24', 25', 26' for lap plates or split bands, and finally rubbing roll pairs 27, 28-29, 30-31, 32-33, 34 and 27',28' - 29',30' - 31',32' - 33',34', with related rubbing coating or bosses 40, 40'.
In this example of embodiment, the motion of card web 12 from card doffer 10, after the doffing action of comb 11, proceeds along a line of the doffer peripheral surface which is covered by the clothing, that is a line which is parallel to the card doffer axis, as usually in any cards. For purposes of illustration only, some data and indications are given which may be useful to better understand the present invention.
Where a card doffer width of 2200 mm is used, the useful width of the doffed card web may be assumed as about 2100 mm. Condenser 17 might split 184 bands to be supplied into correspondent eight spinning frames or, more exactly, four double side spinning frames, each side of which has 35 spindles with a spindle gauge of 90 mm. From each one of doffing rolls 20, 20' of condenser 17, split bands 12' are alternatively branched which pass on the lap plate rolls at the left-hand, and at the right-hand, as in FIG. 1. Each one of these rolls being involved in the motion of one to eight bands being delivered from the condenser. The feed sequence of the eight sides of the spinning frames wherein spindles 42 are mounted was assumed as listed in Table 1, and the numeration is intended from the first split band and first spindle up to the 184th and 23rd, respectively, at the opposite side of condenser 17 and spinning frames 36,37,38,39.
This distribution sequence of split bands supplied by condenser 17 as slubbing to be spun is repeated every eight bands in each spinning frame head, so that in Table 1 was considered as sufficient to list the first two sets of bands only, i.e. I to VIII and IX to XVI, relating to the first and second spindle, respectively, of each spinning head:
Table I______________________________________Band Spinning Spindle Band Spinning SpindleNo. frame No. No. frame No.______________________________________I 36a 1 IX 36a 2II 38a 1 X 38a 2III 36b 1 XI 36b 2IV 38b 1 XII 38b 2V 37a 1 XIII 37a 2VI 39a 1 XIV 39a 2VII 37b 1 XV 37b 2VIII 39b 1 XVI 39b 2______________________________________
As said above, synchronization between the different operative members of machines is provided. It will be apparent to the skilled in the art that, unlike conventional woollen type spinning systems, continuous working needs not only a synchronization in the carding set, but also between finisher card doffer and this new mechanical systems for transferring card web 12, as well as for splitting bands 12', forming slubbings 35 and supplying the spinning frames for the final spinning operation. While no drive member or means are shown in the drawings, it will be apparent that in practice the adaptation and regulation of conventional drive means will be sufficient to meet above requirements of operative synchronism. It was then possible to simplify the illustrations.
As regards the yarns it may be, for example, provided for a starting synchronism between finisher card 10 and second double side spinning frame 37, in order to then provide for the synchronization of the other spinning frames 36,38,39 by using suitable drive means.
The mechanical system which comprises belt conveyor 14, condenser head 17, rubbers or rubbing rolls 27,28 . . . 33,34 and 27',28' . . . 33',34' and related guide rolls could form a single unit having members which are connected therebetween, the control of same being, for example, derived from card 10 or said spinning frame 37.
For the skilled in the art, the requirements of such a synchronism does not result as a problem or a trouble as regards the realization thereof. Same considerations may be done for eventual modifications or changes which relate, for example, to the predetermined position of the condenser head, preferred use of spinning frames having spindles on a single side only, preferred use of rubbing roll pairs as a part of the spinning frame having the desired reduced spinning spindle number and consequent insertion of each pair of rubbers in the driving system of said spinning frame, etc.
More particularly, a consideration may be made about an arrangement of the card doffer comb which is not in a conventional manner, as schematically shown in FIG. 1, but in a lower position below the card doffer, so that the mechanical system of the present invention as well as the spinning frames will then be located on a floor at a lower level in respect to card 10. In this manner doffed web 12 will fall by gravity on to the underlying belt conveyor 14, that is because of its own weight only, for being fed towards condenser head 17, or even directly between the take-in rolls of said condenser head.
In FIG. 4 a modified embodiment of the finisher card is shown, wherein the doffing card comb 111 has its axis in offset position of about 90° clockwise in respect to a conventional card comb 11 as in FIG. 1. Belt conveyor 114 is, in this case, placed directly below the right-hand end portion of card doffer 110, so that the doffed web 112 is falling by gravity along its entire width on to belt conveyor 114, to be transferred towards a condenser head (not shown) similar to condenser head 17 of FIG. 1. Slubbings will then be supplied to the spinning frames for the final spinning thereof, and a set of spinning frames having a reduced spindle number will be used in accordance with the present invention. In such a schematic illustration it was assumed that belt conveyor 114 has horizontal upper and lower runs, doffed card web is falling by gravity from guide roll 15 and passing between roll pair a, a', so that a better guide towards the condenser head (not shown) is obtained, which is arranged on a lower floor.
It will be understood that, when such an arrangement is used, a level difference is necessary between the floors for finisher card and the unit formed by the mechanical system in accordance with the present invention (see FIG. 1) together with the spinning frames having a reduced number of spindles.
That arrangement may be suggested not only for supplying by gravity the doffed card web 112 on to underlying belt conveyor 114, but also where for any reason the installation of spinning machines on floors at different levels is preferred.
In FIG. 5 a direct passage from card doffer 210 to condenser head 217, is illustrated doffed card web 211 being supplied by gravity between a pair of smooth intermediate guide rolls b, b', before its feeding between take-in rolls 216, 216' of condenser head 217, similar to the above modified embodiment shown in FIG. 4.
Selection of this further embodiment, always where the installation on two different level floors one upon the other is preferred for the card and for condenser of the new mechanical system with related spinning frames, respectively, has the advantage of direct supplying condenser 217, without employing any intermediate belt conveyor, as at 14 (FIG. 1) or 114 (FIG. 4).
The advantages of properly using a predetermined surface area for machine installation, as described above and shown in FIGS. 1 to 3 and 4, may be confirmed and further increased when the arrangement on to floors at different levels as in FIG. 5 is possible and then preferred.
While the invention has been described and illustrated in its preferred and modified embodiments, it should be understood that some other embodiments and/or arrangements may be chosen by the skilled in the art, which must be considered as falling within the scope of the invention when based on the inventive principles thereof.
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For working a web of woolen type yarns leaving a finisher card, a condenser head splits the web into parallel bands. The bands are delivered to pairs of rubbing rolls which reciprocate relative to one another to convert the bands to slubbings having false torsion. The slubbings are conveyed to spinning frames.
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This application is a continuation-in-part of application Ser. No. 08/237,337 filed May 3, 1994(abandoned), which is a continuation of application Ser. No. 07/956,770 filed Dec. 17, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
This invention relates to a press machine having a frame which is C-shaped in side elevational view, a bolster which is mounted on a bed of a lower jaw portion of the frame, and a slide which is mounted on an upper jaw portion of the frame. More particularly, this invention relates to a press machine whose side frames are reinforced by reinforcing members.
2. Discussion of Related Art
A prior art example of a press machine i to which the present invention relates is shown in FIG. 1. A frame 2 of the press machine 1 is C-shaped in side elevational view, and has a lower jaw portion with a bed 4 supported thereon, and an upper jaw portion with a slide 5 and a driving unit for driving the slide 5 supported thereon. The arrangement is made such that when the slide 5 is lowered by rotation of a main spindle, a workpiece (not shown) positioned on a lower die 7 mounted on a bolster 4a resting on the bed 4 is punched by an upper die (punch) 6 fixedly secured to the slide 5. In FIG. 1, reference numeral 3 denotes a front side plate of the frame, and reference numeral 8 denotes a side frame.
In the above-mentioned prior art press machine 1, to suppress or reduce the vibration of the frame 2 or the level of noise generated by the press, for example, either (1) a vibration damping material is mounted on the surface of the frame, or (2) the whole press machine is surrounded by a box to isolate the noise. (Refer, for example, to "Examples of Measures for controlling Noise generated by Press Machines", collection of lectures and thesis on technique presentation conferences issued by Japanese Noise Control Engineering Society, P141, September 1989).
Further, as shown in FIGS. 2 and 3, a third prior art alternative (3) for reducing or suppressing the vibration of the frame or the level of noise generated includes mounting an L-shaped reinforcing plate-shaped member 9 on the inner surface of each of the side frames 8.
The problem with mounting a vibration damping material on the surface of the frame, as in the abovementioned case (1), is that it causes an increase in the weight and cost of the entire press machine. For effective vibration damping, the thickness of the vibration damping material must be at least equal to or more than that of the frame, so that if the thickness of the frame is 22 mm, for example, then the total thickness of the frame and the vibration damping material becomes about 50 mm, thus increasing the weight of the entire press machine, giving disadvantages in terms of cost and practicality.
Further, where the whole press machine is surrounded by a box, as in the above-mentioned case (2), other problems exist relating to press operation, cost and the need for increased working space in factories.
Still further, in the above-mentioned alternative (3), as shown in FIGS. 2 and 3, because the plate-shaped member 9 is fixedly secured to each of the side frames 8 as the reinforcing member thereof, the reinforcing effect for preventing the opening formed between the upper and lower jaws of the frame from flaring was limited. Further, the prior art reinforcing member 9 mounted on the side frames 8 so as to extend upwards from the upper jaw portion is inefficient as a reinforcing member since only a small loading is applied to this portion.
A fourth alternative (4) for reducing or suppressing the vibration of the frame is described in Japanese Patent Publication 55-46399. This alternative uses a pair of tie rods 2 extending between opposite side frames 1, 1' of a press machine. The tie rods 2 are fixed to each side frame by means of a nut 3 and a load plate 4, 5. A preload is applied to the tie rods 2 to reduce or suppress at least certain kinds of vibrations occurring in the side frames during operation. The '399 device uses a vibration damping technique which relies on an increased stiffness of the structure to reduce the vibration amplitude. The vibration energy itself is not dispersed into another form of energy (e.g., heat)--it is just converted into a different amplitude.
The '399 device has significant drawbacks. The arrangement of the tie rods 2 between the side frames substantially limits or interferes with the arrangement of a device or mechanisms disposed inside the press machine. Moreover, the preload strain applied to the press body of the device by the tie rods 2 is disadvantageous because it creates damaging stress in the side frames and tends to disorder the positioning accuracy of the mechanisms within the frame. Thus, the use of the tie rods requires readjustment of the mechanisms for proper performance after securing the tie rods, thereby creating an additional inconvenience. Further, the vibration damping effects of the tie rod arrangement of the '399 device is less than satisfactory because the arrangement is not effective against antisymmetric vibrations of the side frames (i.e., both side frames moving in the same direction in the same phase) during operation of the press machine.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-mentioned circumstances in the prior art, and has for its principal object to provide a press machine which is effectively reinforced so as to improve the working accuracy of finished products without installing any special device on the outside of the press machine, without extremely increasing the weight of the entire press machine, and without obstructing the space between the side frames, and which is capable of reducing appreciably the level of noise generated by the machine in operation.
To achieve the above-mentioned object, the inventors of the present invention analyzed the vibration and noise generating mechanism of the existing press machines.
In a press machine 1, as shown in FIG. 1, when a slide 5 is lowered by rotation of a main spindle to allow an upper die (punch) 6 fixedly secured to the slide 5 to punch a workpiece (not shown) on a lower die 7 mounted on a bolster 4a resting on a bed 4, a frame 2 of the press machine 1 is subjected to a resistance to shearing of the workpiece so that a big magnitude of force is exerted on the frame 2. The big magnitude of force tends to flare the opening formed between the upper and lower jaws of the frame. The workpiece is then cracked and broken suddenly. This breaking of the workpiece causes release of the loading therefrom, thus generating shock, which is propagated to the entire press machine, thereby generating noise and vibration.
Further, when the force is exerted on the frame 2, which tends to flare the opening formed between the jaws thereof, a misalignment occurs between the upper die 6 and the lower die 7, thereby tending to reduce the accuracy of finished products.
FIG. 4 is a graph showing the relationship between punching load and noise (breakthrough noise). As shown by this graph, the lower the punching load, that is, the smaller the amount of deformation or flare of the opening of the frame 2 when the press machine is subjected to the resistance of shearing of the workpiece, the lower the level of noise becomes.
In a press machine with a C-shaped frame, the amount of deformation of the notched portion of the upper jaw portion is the biggest. Consequently, if a reinforcing plate is fixedly secured to this upper jaw portion so as to eliminate the notched portion, then the above-named amount of deformation or flare of the opening of the frame 2 is reduced, thus reducing the breakthrough noise.
Further, as another means for reducing the level of the breakthrough noise, noise generating portions of the press machine may be removed. As a result of experiments, it was found out that the noise generated by the rear, upper portion of the side frames is 20% of the noise generated by the entire press machine making this portion the principal noise generating source. Therefore, the breakthrough noise can be reduced by removing this portion.
The foregoing reveals that if the amount of deformation or flare of the opening of the frame of the press machine is suppressed, the noise level can be reduced, and the accuracy of finished products can be improved. The present invention has been made on the basis of this finding.
To achieve the above-mentioned object, according to a first aspect of the present invention, there is provided a press machine having a frame which is C-shaped in side elevational view, a bolster which is mounted on a lower jaw portion of the frame, and a slide and a drive system for driving the slide which are mounted on an upper jaw portion of the frame, characterized in that a means for suppressing vibrations in the side frames without obstructing a space between the side frames is provided including at least one reinforcing member fixedly secured to each of a pair of side frames forming both sides of the frame at at least one predetermined place so as to suppress the deformation or flare of the opening of the frame.
Further, according to a second aspect of the present invention, there is provided a press machine as set forth in the above-mentioned first aspect, characterized in that the reinforcing member has substantially the same shape as a substantially inverted trapezoidal throughhole formed in the rear, upper portion of each of the side frames and has the same thickness as the latter, and is fixedly secured to the upper side surface of an upper jaw portion of each of the side frames.
According to a third aspect of the present invention, there is provided a press machine as set forth in the above-mentioned first aspect, characterized in that the reinforcing member is an L-shaped plate member corresponding to the configuration of a zone which extends from the leading end of the lower jaw portion to the uppermost portion of the innermost upright wall of the recess, and at least two pieces of reinforcing members are superposed and fixedly secured to the zone on the inner surface of each of the side frames.
Further, according to a fourth aspect of the present invention, there is provided a press machine as set forth in the above-mentioned first aspect, characterized in that the reinforcing member is a sheet of strip-shaped plate member, and is fixedly secured to a vertically intermediate portion of the inner surface of each of the side frames along the rear edge thereof.
Yet further, according to a fifth aspect of the present invention, there is provided a press machine as set forth in the above-mentioned first aspect, characterized in that the reinforcing member is a substantially rectangular plate member, and is fixedly secured by means of bolts or by plug welding to the inner surface of each of the side frames at a plurality of places.
According to the present invention incorporating the above-mentioned aspects, the following advantages are obtained.
The press machine is effectively reinforced so as to improve the working accuracy of finished products without the need for installing any special device on the outside thereof, without increasing extremely the weight of the entire press machine, without obstructing the space between the side frames, and which is capable of reducing appreciably the level of noise generated by the machine in operation. The reinforcement is provided without creating a preload stress in the side frames so that an accuracy of the mechanisms within the press frame is maintained, and both asymmetric and symmetric vibrations are effectively suppressed.
Stating in brief, since each of the side frames is reinforced by at least one plate member at at least one suitable place, the deformation of the frame or flare of the opening formed between the upper and lower jaws of the frame which tends to occur in operation is reduced, thereby reducing vibration, and hence, the noise caused thereby, and also improving working accuracy of finished products.
The above-mentioned and other objects, aspects and advantages of the present invention will become apparent to those skilled in the art by making reference to the following description and the accompanying drawings in which preferred embodiments incorporating the principles of the present invention are shown by way of examples only.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, overall perspective view showing a prior art press machine which is C-shaped in side sectional view.
FIG. 2 is a schematic, side elevational view showing a prior art example of reinforcement of a side frame;
FIG. 3 is a sectional view taken along line III--III in FIG. 2;
FIG. 4 is a graph showing the relationship between the punching load and the noise;
FIGS. 5, 6 and 7 are schematic interior side elevational views showing first, second and third embodiments of the present invention;
FIG. 8 is a sectional view taken along line VIII--VIII in FIG. 7;
FIGS. 9A and 9B are plan views showing reinforcing members used in the embodiment shown in FIG. 7;
FIGS. 10 and 11 are schematic interior side elevational views showing a fourth embodiment of the present invention and its variant example;
FIGS. 12 and 13 are fragmentary sectional views showing two examples of reinforcing members for use in the embodiments shown in FIGS. 10 and 11 which are fixedly secured to the side frames; and
FIG. 14 is a graph showing the result of vibration damping experiments conducted in relation to the embodiments shown in FIGS. 10 and 11.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Several embodiments of the present invention will now be described in detail below with reference to FIGS. 5 to 14 of the accompanying drawings.
A first embodiment of the present invention will be described with reference to FIG. 5. In this embodiment, the same component parts as those of the prior art example shown in FIG. 1 are denoted by the same reference numerals, and further description thereof is thus omitted.
In FIG. 5, each of the left and right side frames 10 of a press machine 1 has a substantially inverted trapezoidal through-hole 11 formed in the rear, upper portion thereof. Further, each of the side frames 10 has a notched portion 12 formed above the upper jaw portion on the front side thereof. A piece of reinforcing plate 13 which is of a shape closing the side of the notched portion 12 is fixedly secured by welding to the notched portion 12. The member which is cut out from the side plate 10 to form the through-hole 11 is used as the reinforcing plate 13.
Due to the above-mentioned construction, the area of the rear, upper portion of the side frame 10, which is a principal noise and vibration generating portion, is reduced, thereby reducing the noise and vibration generated in this portion. Further, the notched portion 12 formed above the upper jaw portion, which is subjected to a high loading, is reinforced by the reinforcing plate 13 so that the amount of flare of the opening formed between the upper and lower jaws of the side frames 10 is reduced by about 10% as compared with the prior art example, thereby reducing the breakthrough noise.
The second embodiment of the present invention will be described with reference to FIG. 6.
In FIG. 6, a vertically extending reinforcing plate 14 comprised of a strip-shaped plate member is fixedly secured to each of the left and right side frames 10 forming both side walls of the frame of a press machine along the rear edge of the inner surface thereof.
When the length, height and thickness of the side frame 10 are denoted by L, H and T, the width W of the reinforcing plate 14 is preferably about 0.08 L (W=0.08 L), and the thickness t of the plate 14 (which is the dimension of the plate 14 in a direction at right angles to the side frame 10) is preferably about 1.5 T (t=1.5 T). Further, the height h 1 of the reinforcing plate 14 at the upper end thereof is preferably about 0.77 H (h 1 =0.77 H), and the length h 2 of the plate 14 in the direction of the height thereof is preferably about 0.48 H (h 2 =0.48 H).
An example of the above-mentioned dimensions can be, L=1250 mm, T=55 mm, H=2210 mm, h 1 =1702 mm, and h 2 =1061 mm.
Due to the above-mentioned construction, the deformation of the frame in the transverse direction is reduced by about 10% as compared with the prior art example of FIGS. 2 and 3.
Next, the third embodiment of the present invention will be described with reference to FIGS. 7 to 9B.
In FIG. 7, an L-shaped reinforcing member 15 is fixedly secured to the inner surface of each of the side frames 10 so as to extend from a leading end of a lower-jaw portion 10a of the C-shaped member to the top of a press operation zone 10b. The reinforcing member 15 has a height ι which corresponds to the height of the innermost upright wall of the recess.
The reinforcing member 15 is comprised of a first reinforcing member 16a and a second reinforcing member 16b which are superposed and fixedly secured in two layers.
These reinforcing members 16a and 16b are formed as shown in FIGS. 9A and 9B, respectively. When the height of the press operation zone of the side frame 10 is denoted by ι, the widths W 1 and W 2 of the reinforcing members 16a and 16b are as follows:
W.sub.1 =1/2ι, W.sub.2 =1/3 ι
The ratio of the thickness t 1 of the reinforcing member 16a to the thickness t 2 of the reinforcing member 16b is as follows:
t.sub.1 :t2=1:2.2
One example of the actual dimensions of the reinforcing members 16a, 16b can be, ι=450 mm, W 1 =225 mm, W 2 =150 mm, t 1 =32 mm, and t 2 =70 mm.
In the above-mentioned construction, the frame is reinforced by the first and second reinforcing members 16a and 16b to withstand the loading exerted thereon, which tends to flare the frame.
Next, the fourth embodiment of the present invention and a variant example thereof will be described with reference to FIGS. 10 to 14.
FIGS. 10 and 11 each show only one of the side frames 10 of the press machine. A substantially rectangular plate member 18 (or members 18) is (are) fixedly secured to the inner surface of the side frame 10 which is C-shaped in side view.
There are two examples of the arrangement of the plate member 18 (or members 18). In one example, as shown in FIG. 10, a plurality of plate members 18 each having a small area are fixedly secured to the side frame at a plurality of places. In another example, as shown in FIG. 11, a single piece of plate member 18 having a large area is fixedly secured to the side frame 10 with the longer side thereof extending in the vertical direction. Further, a piece of plate member 18 whose thickness is about one-tenth of that of the side frame 10 or a plurality of separate plate members 18 are fixedly secured in a single layer to the side frame 10. Alternatively, a plurality of superposed plate members 18 each having the same thickness are fixedly secured in the form of one-piece or separate pieces to the side frame 10 as shown in FIGS. 12 and 13. Further, in respect of fixing means, the superposed plate members 18 are fixedly secured by means of bolts 19 to the side frame 10 at a plurality of places, as shown in FIG. 12, or they are fixedly secured by plug welding 20 to the side frame 10 at a plurality of places, as shown in FIG. 13. Preferably the total area of the bolts 20 or the plug welded joints is about 5 to 6% of the surface area of the plate member(s) 18.
In the above-mentioned construction, when vibration is propagated to the side frame 10, the side frame 10 will vibrate together with the plate member 18 (or members 18) fixedly secured thereto. At that time, because both the side frame 10 and the plate member 18 (or members 18) have different natural frequencies and both the members 10 and 18 are fixedly secured to each other at a plurality of places, and held only in contact with each other in the remaining portions, the above-mentioned vibration causes the members 10 and 18 to strike or chafe against each other in the contact portions. Such striking or chafing energy will give a vibration damping effect so that the above-mentioned vibration energy is absorbed into the side frames as heat energy, thereby suppressing the vibration. Thus, the present invention relies on a vibration damping technique which converts vibrations into heat energy and disperses it into the structure itself.
In contrast to the prior art (JP 55-46399) device which has tie rods extending between the side frames and relies on an increased stiffness in the structure to reduce vibration effects, the plate member(s) 18 of the present invention are effective against both symmetric vibrations (the side frames moving in opposing directions) and asymmetric vibrations (both side frames moving in the same direction in phase with each other). Moreover, as is clear from FIGS. 10 to 13 of the drawings, the superposed plate members 18 do not obstruct a space between the side frames 10, as do the tie rods 2 in the '399 device. The plate members 18 provide a means for suppressing vibrations in the side frames 10 while leaving the space between the side frames open for accommodating the most suitable arrangements and sizes of punching and pressing mechanisms (e.g., driving, lubricating, and controlling mechanisms, and the like). As used in this application, the phrase "without obstructing a space between the side frames" means without having a member extending between and connected to the two side frames, such as the tie rods 2 of the '399 device.
Moreover, with the reinforcing plates 18 of the present invention it is not necessary to apply a preload to the side frames. This eliminates the inconveniences resulting from the repositioning of the mechanisms within the press machine of the '399 device after the preloading is applied by the tie rods 2.
Experimental results on the degree of the abovementioned damping of vibration are shown in FIG. 14. In this drawing, reference characters "a" indicate the result obtained when side frames only 14 mm thick are provided, black dots indicate the result obtained when plate members are fixedly secured by plug welding to each of side frames, white dots indicate the result obtained when plate members are fixedly secured by means of bolts to each of the side frames, and X marks indicate the result obtained when prior art vibration damping materials were used.
As is apparent from this graph, the construction according to the present invention could provide nearly the same vibration damping effect as that obtained by the construction using the prior art vibration damping material.
The foregoing description is merely illustrative of preferred embodiments of the present invention, and the scope of the present invention is not to be limited thereto. It will readily occur to those skilled in the art many changes and modifications of the present invention without departing from the scope of the present invention.
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A press machine having side frames which are effectively reinforced so as to appreciably reduce the noise generated during operation of the machine and improve the working accuracy of the machine without installing any special device on the outside thereof, significantly increasing the weight of the entire press machine, or obstructing a space between the side frames of the press machine. The side frames of the press machine are C-shaped in side view and are reinforced by at least one reinforcing member fixedly secured to each of the side frames at at least one predetermined place. The reinforcing members function to suppress the deformation of the opening of the C-shaped side frames to reduce noise and improve accuracy. The reinforcing members convert the vibrational energy of the side frames into heat energy which is then absorbed into the side frames.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a switching power supply that delivers electric power from a DC power supply to a DC load via a transformer.
[0002] Referring to FIG. 19, a conventional fly-back-type switching power supply includes a bridge rectifier Rec that rectifies an AC input and produces pulsating DC power. The pulsating DC power passes through an input reactor L 1 and a series diode D 4 to a primary winding N 1 of a transformer Tr. A switch Q 1 is connected in series with primary winding N 1 . The series combination including input reactor L 1 , switch Q 1 and primary winding N 1 is connected in parallel with bridge rectifier Rec. A capacitor C 1 , preferably an electrolytic capacitor, is connected in parallel with the series combination of primary winding N 1 and switch Q 1 . A snubber capacitor Cs is connected in parallel with switch Q 1 . A switch Q 3 is connected between the output of input reactor L 1 and a common connection of bridge rectifier Rec.
[0003] When switch Q 1 is ON, energy is stored in primary winding N 1 . When switch Q 1 is OFF, stored energy is released through a secondary winding N 2 . The output voltage is regulated by controlling the ON and OFF times of switch Q 1 .
[0004] In the circuit of FIG. 19, so-called soft switching (zero voltage switching), causes switch Q 1 to switch ON when the voltage across snubber capacitor Cs is at its lowest value. This is accomplished by selecting values of the leakage inductance of primary winding N 1 and the capacitance of snubber capacitor Cs so that these elements resonate at the switching speed. Soft switching reduces power loss and improves noise suppression.
[0005] Switch Q 3 is switched ON to produce input current flow through input reactor L 1 . The input current flow improves the power-factor of the circuit. When switch Q 3 is switched ON, energy stored in the input reactor L 1 is fed to electrolytic-type capacitor C 1 . Switching switch Q 3 ON and OFF improves the power-factor even when the input voltage is low, since input current flows whenever the switching power supply is operating.
[0006] The OFF-period of switch Q 1 is set to a length of time determined by the resonant frequency of the series combination of the leakage inductance of primary winding N 1 and snubber capacitor Cs. The OFF-period of switch Q 1 must be related to the resonant frequency to produce soft switching in the switching power supply of FIG. 19. In contrast, the output voltage is regulated only by the On-period of switch Q 1 . Since the ON-period and the OFF-period of switch Q 1 are governed by different criteria, the switching frequency of switch Q 1 must therefore vary to regulate the output voltage while maintaining soft switching.
[0007] Switching power supplies used in television sets and display devices have switching frequencies that are generally synchronized with the deflection frequency. Therefore, a conventional switching power supply that depends on its switching frequency to regulate output voltage is not useful in such variable frequency applications.
[0008] The use of two separate switches Q 1 , Q 3 for voltage regulation and power-factor improvement respectively, increases the noise level of the resulting output of the switching power supply. In addition, diode D 4 in series with switch Q 1 causes a voltage drop when current flows and decreases the switching power supply efficiency.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] In view of the foregoing, it is an object of the present invention to provide a switching power supply which overcomes the above-described drawbacks of the prior art.
[0010] It is a further object of the present invention to provide a switching power supply that facilitates soft switching at arbitrary frequencies.
[0011] It is another object of the present invention to provide a switching power supply with an improved power factor using a simplified scheme.
[0012] It is still another object of the present invention to provide a switching power supply that takes advantage of soft switching.
[0013] It is yet another object of the present invention to provide a switching power supply that facilitates switching at arbitrary frequencies, takes advantage of soft switching and obtains an improved power factor using a simplified scheme.
[0014] It is a still further object of the present invention to provide a switching power supply that has an improved efficiency when driving loads substantially lighter than a rated load.
[0015] It is a yet further object of the present invention to provide a switching power supply with switches and control circuits that are integrated into a single integrated circuit.
[0016] Briefly stated, the present invention provides a switching power supply that uses zero-current and zero-voltage switching to reduce switching noise. A main switch and an auxiliary switch channel current and voltage between various component paths to maintain a DC output voltage while switching in zero-current or zero-voltage states. Switch ON-OFF time ratios are controlled with a simple scheme to improve the circuit power factor. The switching rate is set to arbitrary frequencies, with switch ON time and OFF time being controlled independently. Conventional losses in efficiency when driving a load substantially less than the rated load are avoided. The switches and control functions can be implemented on an integrated circuit, reducing size and improving efficiency. Thus a flexible, simple design improves efficiency while reducing noise and manufacturing costs.
[0017] According to a first aspect of the invention, there is provided a switching power supply that includes a DC power supply; a transformer connected to the DC power supply, the transformer including a primary winding and a secondary winding; a rectifying and smoothing circuit connected to the secondary winding of the transformer; an input reactor; a main semiconductor switch connected in series to the primary winding; a first diode connected in opposite parallel to the main semiconductor switch; a snubber capacitor connected in parallel with the main semiconductor switch; a series circuit for discharging the electric charge of the snubber capacitor, the series circuit including a resonance reactor and an auxiliary semiconductor switch; a second diode connected in opposite parallel to the auxiliary semiconductor switch; and a capacitor connected in parallel to the primary winding.
[0018] Advantageously, the series circuit further includes a resonance capacitor. Advantageously, the switching power supply further including a tertiary winding interposed between the primary winding of the transformer and the main semiconductor switch; and a third diode connected between the auxiliary semiconductor switch and the connection point of the primary winding and the tertiary winding, the third diode connecting the capacitor in parallel to the primary winding.
[0019] Advantageously, the switching power supply including a reactor interposed between the primary winding of the transformer and the main semiconductor switch; and a third diode connected between the auxiliary semiconductor switch and the connection point of the primary winding and the reactor, the third diode connecting the capacitor in parallel to the primary winding.
[0020] According to a second aspect of the invention, there is provided a switching power supply that includes a DC power supply; a transformer connected to the DC power supply, the transformer including a primary winding and a secondary winding; a rectifying and smoothing circuit connected to the secondary winding of the transformer; an input reactor; a main semiconductor switch connected in series to the primary winding; a first diode connected in opposite parallel to the main semiconductor switch; a snubber capacitor connected in parallel to the main semiconductor switch; a series circuit for discharging the electric charges of the snubber capacitor, the series circuit including a resonance capacitor, a resonance reactor and an auxiliary semiconductor switch; and a second diode connected in opposite parallel to the auxiliary semiconductor switch.
[0021] Advantageously, the transformer further includes a quaternary winding substituting for the input reactor.
[0022] According to a third aspect of the invention, there is provided a switching power supply that includes a DC power supply; a transformer connected to the DC power supply, the transformer including a primary winding and a secondary winding; a rectifying and smoothing circuit connected to the secondary winding of the transformer; an input reactor; a main semiconductor switch connected in series to the primary winding; a first diode connected in opposite parallel to the main semiconductor switch; a series circuit including a capacitor and an auxiliary semiconductor switch, the series circuit connected in parallel to the primary winding and the main semiconductor switch; a second diode connected in opposite parallel to the auxiliary semiconductor switch; and a third diode connected between the auxiliary semiconductor switch and the connection point of the primary winding and the main semiconductor switch.
[0023] Advantageously, the transformer further includes a tertiary winding substituting for the input reactor.
[0024] Advantageously, the transformer further includes a tertiary winding interposed between the capacitor and the auxiliary switch of the series circuit, the tertiary winding substituting for the input reactor.
[0025] According to a fourth aspect of the invention, there is provided a switching power supply that includes a rectifier for converting an AC voltage to a DC voltage; a transformer, the transformer including a primary winding, a secondary winding and a tertiary winding; a semiconductor switch connected in series to the primary winding; the semiconductor switch and the primary winding constituting a first series circuit; the rectifier being connected in parallel to the first series circuit; an electrolytic capacitor connected in parallel to the first series circuit; a smoothing and rectifying circuit connected to the secondary winding to deliver DC electric power to a load by the switching-on and -off of the semiconductor switch; and a reverse-recovery diode connected in series to the tertiary winding; the reverse-recovery diode and the tertiary winding constituting a second series circuit connected to the connection point of the rectifier and the electrolytic capacitor.
[0026] By the configuration described above, a voltage is generated across the tertiary winding in opposite polarity to the reverse-recovery diode when the semiconductor switch is switched on. The voltage makes the reverse-recovery diode recover reversely. The reverse-recovery diode then interrupts the current. Since the conventional low-speed diodes are satisfactorily employable in the rectifier, the manufacturing costs of the switching power supply are reduced.
[0027] According to a fifth aspect of the invention, there is provided a switching power supply that includes a rectifier for converting an AC voltage to a DC voltage; a transformer including a primary winding, a secondary winding, a tertiary winding and a quaternary winding; a first semiconductor switch connected in series to the primary winding; the first semiconductor switch and the primary winding constituting a first series circuit; the rectifier being connected in parallel to the first series circuit; an electrolytic capacitor connected in parallel to the first series circuit; a smoothing and rectifying circuit connected to the secondary winding to deliver DC electric power to a load by the switching-on and -off of the first semiconductor switch; a diode connected in series to the quaternary winding; the diode and the quaternary winding constituting a second series circuit connected in series to the electrolytic capacitor; a second semiconductor switch connected in series to the tertiary winding; the second semiconductor switch and the tertiary winding constituting a third series circuit connected in parallel to the electrolytic capacitor.
[0028] Since the quaternary winding discharges through the diode, the electrolytic capacitor, the rectifier and the AC power supply, an input current flows even when the input voltage is lower than the voltage of the electrolytic capacitor. As a result, the conduction angle is widened and, therefore, the power factor is improved. Since the input voltage and the voltage generated across the quaternary winding are applied to the electrolytic capacitor, the electrolytic capacitor is charged up by the voltage higher than the peak value of the input voltage.
[0029] Current flows in the circuit even when the sum of the voltage of the AC power supply and the voltage across the quaternary winding is less than the voltage across the electrolytic capacitor. Although the electrolytic capacitor is not charged, a current flows through the series circuit consisting of the primary winding and the first semiconductor switch, since the series circuit is connected directly to the rectifier. As a result, the conduction angle is widened.
[0030] According to a sixth aspect of the invention, there is provided a switching power supply that includes a DC power supply; a transformer including a primary winding; a main semiconductor switch; the primary winding and the main semiconductor switch constituting a first series circuit connected in series to the DC power supply; a second series circuit including a resonance capacitor, resonance reactor and an auxiliary semiconductor switch, the second series circuit being connected in parallel to the main semiconductor switch to switch on and off only the auxiliary semiconductor switch when the output electric power of the switching power supply is low including in the waiting mode of operation.
[0031] Advantageously, the transformer further includes a tertiary winding substituting for the resonance inductance.
[0032] According to a seventh aspect of the invention, there is provided a switching power supply that includes a main power supply for supplying electric power for driving a load; the main power supply including a DC power supply, a first transformer including a first primary winding, a first semiconductor switch, the first primary winding and the first semiconductor switch constituting a first series circuit connected in series to the DC power supply, and a first integrated circuit, connected to the first semiconductor switch, for driving and for controlling the first semiconductor switch; and a sub power supply for supplying electric power in the waiting mode of operation; the sub power supply including the DC power supply, a second transformer including a second primary winding, a second semiconductor switch, the second primary winding and the second semiconductor switch constituting a second series circuit connected in series to the DC power supply, and a second integrated circuit, connected to the second semiconductor switch, for driving and for controlling the second semiconductor switch; the first semiconductor switch, the first integrated circuit, the second semiconductor switch and the second integrated circuit being integrated and mounted on a common package.
[0033] Advantageously, either one or both of the main power supply and the sub power supply include either one of the switching power supply devices described above.
[0034] Advantageously, the integrated circuits for driving and for controlling the first and second semiconductor switches are integrated into a common control IC.
[0035] According to an embodiment of the present invention there is provided a switching power supply adapted for use with an input DC power supply comprising: an input reactor, a transformer having at least a primary winding and a secondary winding, the primary winding of the transformer connected to the DC power supply through the input reactor, a rectifying and smoothing circuit connected to the secondary winding of the transformer, a main semiconductor switch connected in series with the primary winding, a first diode connected in opposite parallel with the main semiconductor switch, a snubber capacitor connected in parallel with the main semiconductor switch, a series circuit including a resonance component and an auxiliary semiconductor switch connected in parallel with the main semiconductor switch, the series circuit being effective to discharge an electric charge of the snubber capacitor, and a second diode connected in opposite parallel with the auxiliary semiconductor switch.
[0036] According to another embodiment of the present invention there is provided a switching power supply adapted for use with an input DC power supply comprising: an input reactor, a transformer having at least a primary winding and a secondary winding, the primary winding of the transformer connected to the DC power supply through the input reactor, a rectifying and smoothing circuit connected to the secondary winding of the transformer, a main semiconductor switch connected in series with the primary winding, a first diode connected in opposite parallel with the main semiconductor switch, a series circuit including a capacitor and an auxiliary semiconductor switch, the series circuit connected in parallel with the primary winding and the main semiconductor switch, a second diode connected in opposite parallel with the auxiliary semiconductor switch, and a third diode interposed between the primary winding and the auxiliary semiconductor switch.
[0037] According to still another embodiment of the present invention there is provided a switching power supply comprising: a rectifier effective to convert an AC voltage to a DC voltage, a transformer having at least a primary winding, a secondary winding and a tertiary winding, a semiconductor switch connected in series with the primary winding, the primary winding connected to the rectifier through the tertiary winding, an electrolytic capacitor connected in parallel with the semiconductor switch and the primary winding, a smoothing and rectifying circuit connected to the secondary winding, the smoothing and rectifying circuit being effective to deliver DC electric power to a load, the semiconductor switch being effective to regulate the DC electric power when the semiconductor switch is switched ON and OFF, and a high-speed reverse-recovery diode interposed between the tertiary winding and a connection point of the electrolytic capacitor and the primary winding.
[0038] According to still another embodiment of the present invention there is provided a switching power supply comprising: a rectifier effective to convert an AC voltage to a DC voltage, a transformer having at least a primary winding, a secondary winding, a tertiary winding and a quaternary winding, a first semiconductor switch connected in series with the primary winding, the rectifier being connected in parallel with the first semiconductor switch and the primary winding, a smoothing and rectifying circuit connected to the secondary winding, the smoothing and rectifying circuit being effective to deliver DC electric power to a load, the semiconductor switch being effective to regulate the DC electric power when the semiconductor switch is switched ON and OFF, a first series circuit including the quaternary winding, a diode and an electrolytic capacitor, the first series circuit connected in parallel with the first semiconductor switch and the primary winding, a second semiconductor switch connected in series with the tertiary winding, and the second semiconductor switch and the tertiary winding connected in parallel with the electrolytic capacitor.
[0039] According to yet another embodiment of the present invention there is provided a switching power supply adapted for use with an input DC power supply comprising: a transformer having at least a primary winding and a secondary winding, a main semiconductor switch connected in series with the primary winding, the primary winding connected to the DC power supply, a smoothing and rectifying circuit connected to the secondary winding, the smoothing and rectifying circuit being effective to deliver DC electric power to a load, a series circuit including a resonance capacitor, a resonance reactor and an auxiliary semiconductor switch, the series circuit connected in parallel with the main semiconductor switch, the main semiconductor switch being switched OFF when the switching power supply drives a light load substantially smaller than a rated load, and the auxiliary semiconductor switch being effective to regulate the light load when the auxiliary semiconductor switch is switched ON and OFF.
[0040] According to another embodiment of the present invention there is provided a switching power supply adapted for use with an input DC power supply comprising: a main power supply effective to supply electric power to a rated load, the main power supply including a first transformer, the first transformer having at least a first primary winding, the at least first primary winding connected to the DC power supply, a first semiconductor switch connected to the at least first primary winding, a first integrated circuit connected to the first semiconductor switch effective to drive and control the first semiconductor switch, a sub power supply effective to supply electric power to a load substantially smaller than the rated load, the sub power supply including a second transformer, the second transformer having at least a second primary winding, the at least second primary winding connected to the DC power supply, a second semiconductor switch connected in series with the at least second primary winding and a second integrated circuit connected to the second semiconductor switch effective to drive and control the second semiconductor switch.
[0041] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] [0042]FIG. 1 is a circuit diagram of a switching power supply according to a first embodiment of the invention.
[0043] [0043]FIG. 2 is a time chart for explaining the operation of the switching power supply of FIG. 1.
[0044] [0044]FIG. 3 is a circuit diagram of a switching power supply according to a second embodiment of the invention.
[0045] [0045]FIG. 4 is a circuit diagram of a switching power supply according to a third embodiment of the invention.
[0046] [0046]FIG. 5 is a circuit diagram of a switching power supply according to a fourth embodiment of the invention.
[0047] [0047]FIG. 6 is a circuit diagram of a switching power supply according to a fifth embodiment of the invention.
[0048] [0048]FIG. 7 is a circuit diagram of a switching power supply according to a sixth embodiment of the invention.
[0049] [0049]FIG. 8 is a circuit diagram of a switching power supply according to a seventh embodiment of the invention.
[0050] [0050]FIG. 9 is a circuit diagram of a switching power supply according to an eighth embodiment of the invention.
[0051] [0051]FIG. 10 is a circuit diagram of a switching power supply according to a ninth embodiment of the invention.
[0052] [0052]FIG. 11 is a circuit diagram of a switching power supply according to a tenth embodiment of the invention.
[0053] [0053]FIG. 12 is a circuit diagram of a switching power supply according to an eleventh embodiment of the invention.
[0054] [0054]FIG. 13 is a circuit diagram of a switching power supply according to a twelfth embodiment of the invention.
[0055] [0055]FIG. 14 is a circuit diagram of a switching power supply according to a thirteenth embodiment of the invention.
[0056] [0056]FIG. 15 is a circuit diagram of a general switching power supply for driving a light load as well as for driving a rated load.
[0057] [0057]FIG. 16( a ) is a top plan view of a power IC of FIG. 15.
[0058] [0058]FIG. 16( b ) is another top plan view of another power IC of FIG. 15.
[0059] [0059]FIG. 17 is a top plan view of a power IC package according to the invention.
[0060] [0060]FIG. 18 is another top plan view of another power IC package according to the invention.
[0061] [0061]FIG. 19 is a circuit diagram of a conventional fly-back-type switching power supply.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0062] Referring now to FIG. 1, an input reactor L 1 is connected to a DC power supply DC. A primary winding N 1 and a tertiary winding N 3 of a transformer Tr and a main switch Q 1 are connected in series to input reactor L 1 . A diode DI is connected in parallel across main switch Q 1 so that current flows only in an opposite direction to that of main switch Q 1 . A snubber capacitor Cs is also connected in parallel with the main switch Q 1 . A series circuit consisting of a resonance capacitor C 2 , a resonance reactor L 2 and an auxiliary switch Q 2 is connected in parallel with snubber capacitor Cs. A diode D 2 is connected in parallel with auxiliary switch Q 2 , so that current flows in a direction opposite to the current flow in auxiliary switch Q 2 . A diode D 3 is connected between auxiliary switch Q 2 and the connection point of primary winding N 1 and tertiary winding N 3 . A series combination of capacitor C 1 and diode D 3 is connected in parallel with primary winding N 1 .
[0063] Referring now to FIG. 2, auxiliary switch Q 2 is switched ON in advance of main switch Q 1 being switched ON. When auxiliary switch Q 2 is switched ON, the voltage across snubber capacitor Cs decays to zero. Switching auxiliary switch Q 2 ON also engages a first resonance series of resonance capacitor C 2 , resonance reactor L 2 , and snubber capacitor Cs. A resonance circuit is completed through auxiliary switch Q 2 . The voltage across auxiliary switch Q 2 drops to zero, and the current through auxiliary switch Q 2 increases very slowly as the current through snubber capacitor Cs drops to zero. The low current allows auxiliary switch Q 2 to execute zero-current switching.
[0064] When the voltage across snubber capacitor Cs decays to zero, main switch Q 1 is switched ON, thus achieving zero-voltage switching. As main switch Q 1 switches ON, a second resonance series of resonance capacitor C 2 and resonance reactor L 2 is engaged. A resonance circuit is completed by main switch Q 1 and diode D 2 . When current flows through diode D 2 , the voltage across auxiliary switch Q 2 is zero. Auxiliary switch Q 2 is then switched OFF and achieves zero-voltage switching.
[0065] Since the voltage across snubber capacitor Cs decays to zero when auxiliary switch Q 2 is switched ON, main switch Q 1 achieves zero-voltage switching when it is switched OFF. When main switch Q 1 is switched OFF, the voltage across snubber capacitor Cs rises gradually to a steady value. Furthermore, switching main switch Q 1 OFF regenerates the charge in capacitor C 1 from the electric charge stored in resonance capacitor C 2 . Capacitor C 1 is further recharged by the energy stored in the leakage inductance of the primary winding N 1 via diode D 3 .
[0066] Referring now to FIG. 3, a circuit diagram of a switching power supply according to a second embodiment of the invention is shown. The circuit of FIG. 3 is similar to that of FIG. 1, except for the absence of resonance capacitor C 2 . Also in FIG. 3, resonance reactor L 2 is directly connected to auxiliary switch Q 2 .
[0067] The circuit of FIG. 3 functions similarly to that of the above described circuit of FIG. 1. Auxiliary switch Q 2 is switched ON in advance of main switch Q 1 , forming a resonance circuit with the resonance series of snubber capacitor Cs and resonance reactor L 2 . When switched ON, auxiliary switch Q 2 has very little current flowing through it and is thus able to achieve zero-current switching.
[0068] Main switch Q 1 achieves zero-voltage switching by being switched ON when the voltage across snubber capacitor is zero. When auxiliary switch Q 2 is switched ON, the voltage of snubber capacitor Cs decays to zero. Switching main switch Q 1 ON keeps the voltage of snubber capacitor Cs at zero. When main switch Q 1 is switched OFF, the voltage across snubber capacitor Cs gradually rises to a steady value. Thus when it is switched OFF, main switch Q 1 achieves zero-voltage switching. Furthermore, when main switch Q 1 is switched OFF, the energy stored in the leakage inductance of primary winding N 1 is regenerated to capacitor C 1 via diode D 3 .
[0069] Referring now to FIG. 4, a circuit diagram of a switching power supply according to a third embodiment of the present invention is shown. In this embodiment, tertiary winding N 3 of FIG. 1 is replaced with a reactor L 3 . As with the circuit of FIG. 1, auxiliary switch Q 2 is switched ON in advance of main switch Q 1 . Auxiliary switch Q 2 makes a resonance circuit which includes the resonance series of snubber capacitor Cs, resonance capacitor C 2 and resonance reactor L 2 . Very little current flows through the resonance series prior to auxiliary switch Q 2 switching ON, which achieves zero-current switching.
[0070] The circuit of FIG. 4 otherwise operates in the same manner as that of FIG. 1 and a duplicated explanation is therefore omitted. The replacement of tertiary winding N 3 in FIG. 3 with reactor L 3 does not otherwise alter the operability of the circuit.
[0071] Referring now to FIG. 5, a circuit diagram of a switching power supply according to a fourth embodiment of the invention is shown. In this embodiment, diode D 3 of FIG. 1 is omitted and tertiary winding N 3 is short-circuited to provide primary winding N 1 with further windings in transformer Tr. As with the circuit of FIG. 1, auxiliary switch Q 2 is switched ON in advance of main switch Q 1 . When auxiliary switch Q 2 is switched ON, the voltage across snubber capacitor Cs decays to zero. Switching auxiliary switch Q 2 ON provides a resonance circuit that includes first resonance series of snubber capacitor Cs, resonance capacitor C 2 and resonance reactor L 2 . Very little current flows through the resonance series prior to auxiliary switch Q 2 switching ON, which achieves zero-current switching.
[0072] When the voltage across snubber capacitor Cs decays to zero, main switch Q 1 is switched ON, thus achieving zero-voltage switching. As main switch Q 1 switches ON, a second resonance series of resonance capacitor C 2 and resonance reactor L 2 is engaged. A resonance circuit is completed by main switch Q 1 and diode D 2 . When current flows through diode D 2 , the voltage across auxiliary switch Q 2 is zero. Auxiliary switch Q 2 therefore achieves zero-voltage switching upon being switched OFF.
[0073] The voltage across snubber capacitor Cs decays to zero when auxiliary switch Q 2 is switched ON, and remains zero during the period when main switch Q 1 is switched ON. When main switch Q 1 is switched OFF, the voltage across snubber capacitor Cs is still zero, thus achieving zero-voltage switching. Once main switch Q 1 is switched OFF, the voltage of snubber capacitor Cs rises gradually to a steady value. Furthermore, switching main switch Q 1 OFF regenerates the charge in capacitor C 1 from the electric charge stored in resonance capacitor C 2 .
[0074] Referring now to FIG. 6, a circuit diagram of a switching power supply according to a fifth embodiment of the invention is shown. A DC input is connected in series to a main switch Q 1 and a primary winding N 1 of a transformer Tr. A diode D 1 is connected in parallel across main switch Q 1 so that current flows through diode D 1 only in a direction opposite to that of main switch Q 1 . A snubber capacitor Cs is connected in parallel with main switch Q 1 . A series circuit consisting of a resonance capacitor C 2 , a resonance reactor L 2 and an auxiliary switch Q 2 is connected in parallel with the snubber capacitor Cs. A diode D 2 is connected in parallel across auxiliary switch Q 2 so that current flows only in an opposite direction to that of main switch Q 1 .
[0075] As with the circuit of FIG. 1, auxiliary switch Q 2 is switched ON in advance of main switch Q 1 . When auxiliary switch Q 2 is switched ON, the voltage across snubber capacitor Cs decays to zero. Switching auxiliary switch Q 2 ON provides a resonance circuit that includes first resonance series of snubber capacitor Cs, resonance capacitor C 2 and resonance reactor L 2 . Very little current flows through the resonance series prior to auxiliary switch Q 2 switching ON, which achieves zero-current switching.
[0076] When the voltage across snubber capacitor Cs decays to zero, main switch Q 1 is switched ON, thus achieving zero-voltage switching. As main switch Q 1 switches ON, a second resonance series of resonance capacitor C 2 and resonance reactor L 2 is engaged. A resonance circuit is completed by main switch Q 1 and diode D 2 . When current flows through diode D 2 , the voltage across auxiliary switch Q 2 is zero. Auxiliary switch Q 2 therefore achieves zero-voltage switching upon being switched OFF.
[0077] The voltage across snubber capacitor Cs decays to zero when auxiliary switch Q 2 is switched ON, and remains zero during the period when main switch Q 1 is switched ON. When main switch Q 1 is switched OFF, the voltage across snubber capacitor Cs is still zero, thus achieving zero-voltage switching. Once main switch Q 1 is switched OFF, the voltage of snubber capacitor Cs rises gradually to a steady value.
[0078] Referring now to FIG. 7, a circuit diagram of a switching power supply according to a sixth embodiment of the invention is shown. In this embodiment, input reactor L 1 of FIG. 1 is replaced by a quaternary winding N 4 of a transformer Tr.
[0079] As with the circuit of FIG. 1, auxiliary switch Q 2 is switched ON in advance of main switch Q 1 . When auxiliary switch Q 2 is switched ON, the voltage across snubber capacitor Cs decays to zero. Switching auxiliary switch Q 2 ON provides a resonance circuit that includes first resonance series of snubber capacitor Cs, resonance capacitor C 2 and resonance reactor L 2 . Very little current flows through the resonance series prior to auxiliary switch Q 2 switching ON, which achieves zero-current switching.
[0080] The circuit of FIG. 7 otherwise operates in the same manner as that of FIG. 1 and a duplicated explanation is therefore omitted. Moreover, the replacement of input reactor L 1 with quaternary winding N 4 in FIGS. 3, 4 and 5 does not otherwise alter the operability of the circuit.
[0081] The following embodiments focus on providing a switching power supply that exhibits a high power factor.
[0082] Referring now to FIG. 8, a circuit diagram of a switching power supply according to a seventh embodiment of the invention is shown. A pulsed DC input is connected to an input reactor L 1 . A series circuit consisting of a primary winding N 1 of a transformer Tr and a main switch Q 1 is connected in series to the input reactor L 1 . A diode Di is connected in parallel across main switch Q 1 so that current flows through diode D 1 only in a direction opposite to that of main switch Q 1 . A series circuit consisting of a capacitor C 1 and an auxiliary switch Q 2 is connected in parallel with the series circuit of primary winding N 1 and main switch Q 1 . A diode D 2 is connected in parallel across auxiliary switch Q 2 so that current flows through diode D 2 only in a direction opposite to that of auxiliary switch Q 1 . A diode D 3 is connected between auxiliary switch Q 2 and the connection point of primary winding N 1 and main switch Q 1 .
[0083] The switching power supply operates by first switching ON main switch Q 1 to provide an input current flow. Switching main switch Q 1 ON improves the power factor of the power supply because input current flows even with low input voltage. When main switch Q 1 is switched OFF, a portion of the excitation energy within transformer Tr is stored in capacitor C 1 which is connected in parallel with primary winding N 1 of transformer Tr through diode D 3 .
[0084] Auxiliary switch Q 2 is then switched ON, causing the energy stored in capacitor C 1 to be transferred to input reactor L 1 through a rectifier Rec.
[0085] Switching auxiliary switch Q 2 OFF then causes the energy stored in input reactor L 1 to be transferred to the transformer Tr. The result is that the energy stored in capacitor C 1 is fed to the load.
[0086] Referring now to FIG. 9, a circuit diagram of a switching power supply according to an eighth embodiment of the present invention is shown. This embodiment is substantially the same as that of FIG. 8, except that input reactor L 1 in FIG. 8 is replaced with a tertiary winding N 3 of transformer Tr. The operation of the switching power supply of FIG. 9 is substantially the same as that of the switching power supply of FIG. 8 and an explanation will therefore be omitted for the sake of simplicity.
[0087] Referring now to FIG. 10, a circuit diagram of a switching power supply according to a ninth embodiment of the present invention is shown. This embodiment is substantially the same as that of FIG. 8, except that input reactor L 1 in FIG. 8 is omitted. A tertiary winding N 3 of a transformer Tr is connected between a capacitor C 1 and an auxiliary switch Q 2 . The operation of the circuit is otherwise substantially the same as that of the switching power supply of FIG. 8 and an explanation will therefore be omitted for the sake of brevity.
[0088] The embodiments of the present invention presented to this point represent switching power supplies with fly-back-type power converters. As explained below, the present invention is also applicable to switching power supplies with fly-forward-type power converters.
[0089] Referring now to FIG. 11, a circuit diagram of a switching power supply according to a tenth embodiment of the present invention is shown. In this embodiment, a high-speed reverse-recovery diode D 2 is connected in series between a tertiary winding N 3 and a primary winding N 1 of a transformer Tr. Tertiary winding N 3 is connected in series to a rectifier Rec that rectifies an input AC voltage to a pulsed DC voltage. An electrolytic capacitor C 1 is connected between primary winding N 1 and the common connection of rectifier Rec. A semiconductor switch Q 1 is connected in series with primary winding N 1 . A diode D 1 is connected in parallel with semiconductor switch Q 1 so that current flows through diode D 1 only in a direction opposite to that of semiconductor switch Q 1 .
[0090] The circuit of FIG. 11 operates by first switching ON semiconductor switch Q 1 . When semiconductor switch Q 1 is switched ON, a voltage is generated across tertiary winding N 3 in opposite polarity to diode D 2 . The opposite polarity voltage causes diode D 2 to be reversed biased. Since the reverse recovery of diode D 2 occurs at high speed, the current is quickly interrupted and no current flows through rectifier Rec. The characteristic of high speed current interruption provided by diode D 2 makes it unnecessary to specify that rectifier Rec have high-speed reverse-recovery performance. Rectifier Rec can then be constructed from conventional low-speed diodes, thus significantly reducing the manufacturing costs associated with the switching power supply.
[0091] Referring now to FIG. 12, a circuit diagram of a switching power supply according to an eleventh embodiment of the present invention is shown. In this embodiment, a semiconductor switch Q 1 is connected in series to a primary winding N 1 of a transformer Tr. A diode D 1 is connected in parallel across semiconductor switch Q 1 so that current flows through diode D 1 only in a direction opposite to that of semiconductor switch Q 1 . A series circuit consisting of a quaternary winding N 4 of transformer Tr, a diode D 3 and an electrolytic capacitor C 1 is connected between primary winding N 1 and a common connection of rectifier Rec. A series circuit consisting of a tertiary winding N 3 of the transformer Tr and a semiconductor switch Q 2 is connected in parallel with the electrolytic capacitor C 1 . A diode D 2 is connected in parallel across second semiconductor switch Q 2 so that current flows through diode D 2 only in a direction opposite to that of semiconductor switch Q 2 .
[0092] Semiconductor switch Q 1 provides a portion of the control of the operation of the switching power supply. When semiconductor switch Q 1 is switched ON, energy is stored in primary winding N 1 of transformer Tr. As energy is stored in primary winding N 1 , a voltage is generated across quaternary winding N 4 of transformer Tr. The voltage across quaternary winding N 4 has a polarity that is positive towards the connection to rectifier Rec and negative towards the connection to electrolytic capacitor C 1 . This voltage across quaternary winding N 4 prevents electrolytic capacitor C 1 from being charged up.
[0093] Switching semiconductor switch Q 1 OFF causes the energy stored in primary winding N 1 to be transferred to secondary winding N 2 and quaternary winding N 4 of transformer Tr. Energy transferred to secondary winding N 2 is fed to the load through a rectifier Rec 1 . As energy is transferred from primary winding N 1 , a voltage is generated across quaternary winding N 4 . The polarity of the voltage across quaternary winding N 4 is negative towards the connection to rectifier Rec and positive towards the connection to electrolytic capacitor C 1 . This voltage across quaternary winding N 4 feeds energy through diode D 3 to charge electrolytic capacitor C 1 .
[0094] Semiconductor switch Q 2 provides another portion of the control of the operation of the switching power supply. When semiconductor switch Q 2 is switched ON, electrolytic capacitor C 1 is discharged through tertiary winding N 3 . The discharging current stores energy tertiary winding N 3 of transformer Tr. As energy is stored in tertiary winding N 3 , a voltage is generated across quaternary winding N 4 of the transformer Tr. The polarity of the voltage across quaternary winding N 4 is positive towards the connection to rectifier Rec and negative towards the connection to electrolytic capacitor C 1 . This voltage across quaternary winding N 4 prevents electrolytic capacitor C 1 from being charged.
[0095] Switching semiconductor switch Q 2 OFF causes the energy stored in tertiary winding N 3 to be transferred to secondary winding N 2 and quaternary winding N 4 of transformer Tr. The energy transferred to secondary winding N 2 is fed to the load through rectifier Rec 1 . As energy is transferred from tertiary winding N 3 , a voltage is generated across quaternary winding N 4 . The polarity of the voltage across quaternary winding N 4 is negative towards the connection to rectifier Rec and positive towards the connection to electrolytic capacitor C 1 . This voltage across quaternary winding N 4 feeds energy through diode D 3 to charge electrolytic capacitor C 1 .
[0096] In the above described circuit operation, quaternary winding N 4 discharges either by switching semiconductor switch Q 1 or semiconductor switch Q 2 . An input current therefore flows through the path connecting quaternary winding N 4 , diode D 3 , electrolytic capacitor C 1 , rectifier Rec and alternating power supply AC, even when the input voltage is lower than that of electrolytic capacitor C 1 . The uninterrupted current flow widens the conduction angle and improves the power factor.
[0097] The operation of the above described circuit provides a voltage sum applied to capacitor C 1 . The voltage across quaternary winding N 4 and the input voltage combine during specific intervals to apply a charge voltage to capacitor C 1 . This voltage charges capacitor C 1 to a value that is greater than the peak value of the input voltage.
[0098] The voltage of power supply AC drops during specific intervals to the point where the sum of the voltage of power supply AC and quaternary winding N 4 is less than the voltage of the electrolytic capacitor C 1 . When the combined voltage of power supply AC and quaternary winding N 4 reaches falls to this point, electrolytic capacitor C 1 is not charged. During the interval when electrolytic capacitor C 1 is not charged, a current still flows through the series circuit consisting of primary winding N 1 and semiconductor switch Q 1 . The current flows through rectifier Rec and widens the conduction angle, thus improving the power factor of the circuit.
[0099] In the above described circuit operation, semiconductor switch Q 1 and semiconductor switch Q 2 have been described as operating independent of each other. It should be recognized that the circuit also operates properly when semiconductor switches Q 1 , Q 2 are switched simultaneously or in sequence.
[0100] Television sets and other similar portable devices generally have a so-called waiting mode when operating normally. In this waiting mode the load on the power supply from the device is about {fraction (1/100)} as great as the rated load of the device. Under this type of light-load condition the conversion efficiency of the power supply is greatly diminished. This loss of efficiency is particularly notable when the electric power to the device is regulated by a conventional switching power supply as shown in FIG. 19.
[0101] The loss of efficiency is related to the switches being driven for the rated load, which produces electric power much too great for the light load. Moreover, the transformer is energized with a rectangular wave that is shaped to deliver power for the rated load. The shape of the energizing wave produces a high peak current in a short interval. Thus, when the load on the transformer lightens, energy within the transformer is dispersed through high copper losses.
[0102] Furthermore, the loss of efficiency due to high driving power and copper losses results in the battery of the portable device being rapidly consumed. The operational life of the portable device is therefore shortened. The shortened operating life presents farther difficulties in meeting power consumption regulations.
[0103] Referring now to FIG. 13, a circuit diagram of a switching power supply according to a twelfth embodiment of the present invention is shown that facilitates obviating the foregoing problems. In this embodiment, a series circuit consisting of a resonance reactor L 1 , a resonance capacitor C 2 and an auxiliary switch Q 2 is connected in parallel with a main switch Q 1 . Auxiliary switch Q 2 is rated at a value which is about {fraction (1/10)} as high as that of main switch Q 1 .
[0104] The switching power supply of FIG. 13 operates by storing energy in a transformer Tr when main switch Q 1 is switched ON. A snubber capacitor Cs connected in parallel with main switch Q 1 is charged when the circuit operates and auxiliary switch Q 2 is switched OFF. Auxiliary switch Q 2 is switched ON in advance of main switch Q 1 being switched ON. Switching auxiliary switch Q 2 ON causes the electric charge in snubber capacitor Cs to be discharged through resonance capacitor C 2 and resonance reactor L 1 . Once the voltage of snubber capacitor Cs has fallen to zero, main switch Q 1 is switched ON. Switching main switch Q 1 ON while snubber capacitor Cs is discharged achieves zero-voltage switching with main switch Q 1 .
[0105] When the power supply is operating under light-load conditions such as, for example, in waiting mode, auxiliary switch Q 2 is switched ON while main switch Q 1 is switched OFF. When only auxiliary switch Q 2 is switched ON, a current flows through the series circuit consisting of primary winding N 1 , resonance capacitor C 2 and resonance reactor L 1 . Due to the presence of resonance capacitor C 2 , the load is driven only with current flowing through the resonance series circuit and auxiliary switch Q 2 . When this current drives the load, the voltage of primary winding N 1 decreases as the voltage of resonance capacitor C 2 increases. When the voltage of resonance capacitor C 2 exceeds the input voltage, the voltage of primary winding N 1 reverses polarity and current flows in through primary winding N 1 in an opposite direction. The current through primary winding N 1 supplies a voltage across secondary winding N 2 . The voltage across secondary winding N 2 increases until it exceeds an output voltage Vo. When the voltage of secondary winding N 2 exceeds output voltage Vo, a diode D 1 becomes forward biased and transfers the energy stored in secondary winding N 2 to the load.
[0106] When a rated load is driven, main switch Q 1 is ON and the input voltage is applied directly to primary winding N 1 of transformer Tr. The current that flows through primary winding N 1 in this instance has a triangular wave form.
[0107] When a light load is driven, only auxiliary switch Q 2 is switched ON. The current in this instance is suppressed to a value determined by the impedance of resonance capacitor C 2 , resonance reactor L 1 and the excitation inductance of transformer Tr. In this configuration, resonance capacitor C 2 is selected to have a capacitance corresponding to the rating of the light load. The smaller capacitance of resonance capacitor C 2 reduces the current through transformer Tr, so that the peak value of the current is less than the peak value of the triangular wave form of the rated current. A lower peak value for the current reduces losses in transformer Tr and conduction losses in switches Q 1 , Q 2 . Since the rating of auxiliary switch Q 2 is approximately {fraction (1/10)} of that of main switch Q 1 , the electric power that drives the light load is suppressed to approximately {fraction (1/10)} of the electric power that drives the rated load.
[0108] Referring now to FIG. 14, a circuit diagram of a switching power supply according to a thirteenth embodiment of the present invention is shown. In this embodiment, resonance reactor L 1 of FIG. 13 is replaced by a tertiary winding N 3 of a transformer Tr.
[0109] The circuit of FIG. 14 operates in substantially the same manner as the circuit of FIG. 13. The main difference is that switching auxiliary switch Q 2 ON connects primary winding N 1 in series with tertiary winding N 3 . The excitation inductance of tertiary winding N 3 is proportional to the square of the number of turns of the winding. The excitation inductance of tertiary winding N 3 is made very large by adding only a few turns to primary winding N 1 of transformer Tr. The high excitation inductance of tertiary winding N 3 achieves a lower peak value for the current through transformer Tr. In addition, resonance reactor L 1 is a constituent element of the circuit in FIG. 13. Replacing resonance reactor L 1 with tertiary winding N 3 reduces the number of constituent elements, while still providing the capability of efficiently driving a light load.
[0110] Although the switching power supply of FIGS. 13 or 14 are described driving the rated load and the light load (in the waiting mode of operation) with the same circuit, two separate circuits are usually used to drive the rated load and the light load, respectively.
[0111] Referring now to FIG. 15, a circuit diagram of a general switching power supply for driving a light load and a rated load is shown. In this embodiment, the switching power supply includes a main power supply and a sub power supply. The main power supply includes capacitors C 1 , C 3 and C 4 , a transformer Tr 1 , a power integrated circuit (“power IC”) IC 1 and diodes D 5 , D 6 . The sub power supply includes capacitors C 5 , C 11 , a transformer Tr 2 , a power IC IC 2 and a diode D 7 . Power IC IC 1 includes a MOSFET Q 1 and a control integrated circuit (“control IC”) IC 11 . Power IC IC 2 includes a MOSFET Q 11 and a control IC IC 21 .
[0112] When a load (not shown) is driven, DC power is fed to a main circuit power supply that includes diode D 5 and capacitor C 3 , and to a CPU power supply that includes diode D 6 and capacitor C 4 . The DC power is generated by switching MOSFET Q 1 ON and OFF such that an AC voltage is applied to transformer Tr 1 . Control IC IC 11 adjusts the main circuit power supply to a specific value by detecting and comparing the output voltage with a reference voltage. The results of the comparison are used to regulate the ON-OFF time ratio of MOSFET Q 1 .
[0113] When driving a light load in the waiting mode of operation, MOSFET Q 11 is switched ON and OFF and MOSFET Q 1 is not driven. Switching MOSFET Q 11 ON and OFF applies an AC voltage to transformer Tr 2 which in turn supplies DC power to only the CPU power supply. In this configuration, DC power provided through diode D 7 and capacitor C 5 is fed only to the CPU power supply. Control IC IC 21 adjusts the CPU power supply to a specific value by detecting and comparing the output voltage with a reference voltage. The results of the comparison are used to regulate the ON-OFF time ratio of MOSFET Q 11 . In this configuration the consumed power is reduced to several watts which provides compliance with various energy regulations.
[0114] Referring now to FIGS. 16 ( a )-( b ), top plan views of power IC IC 1 and IC 2 are shown. Each power IC package includes a chip that has an insulative substrate on which a copper pattern is formed. The chip must be electrically isolated from a terminal and from a casing to function properly. This requirement increases the size of the respective power ICs and also adds to their cost.
[0115] Referring now to FIG. 17, a top plan view of a power IC package according to an embodiment of the present invention is shown. This embodiment obviates the above described problems inherent in the individual power IC packages.
[0116] The IC package according to the present invention mounts the structure of power ICs IC 1 and IC 2 on a common insulative substrate. The common mounting reduces the total area needed to realize the power IC and thus reduces the total cost of the power ICs IC 1 and IC 2 .
[0117] Referring now to FIG. 18, a top plan view of another power IC package according to an embodiment of the present invention is shown. In this embodiment, the functions of the control ICs IC 1 and IC 2 are integrated into a single control IC. This integration is possible because control ICs IC 1 and IC 2 have almost the same structure and function.
[0118] Integration of various switching power supply devices is not limited to that described in connection with the general switching power supply illustrated in FIG. 15 . The various switching power supplies shown and described in FIGS. 1 through 14 may also be integrated and achieve equivalent efficiencies in cost and size. When any of the various switching power supplies described in FIGS. 1 through 15 must handle a light load associated with the waiting mode of operation, control ICs may be used in place of main and auxiliary switches. Alternatively, a control IC may be used that has common main and auxiliary switches disposed thereon.
[0119] The following are some examples of the advantages of the various embodiments of the present invention.
[0120] Since zero-voltage switching and zero-current switching are obtained, the switching loss is reduced.
[0121] Since dv/dt during switching is small, noise is reduced.
[0122] The switching power supply according to the invention is adaptable to TV sets and display devices that synchronize the switching frequency with the deflection frequency.
[0123] The power factor is improved and noise is reduced. Moreover, the output voltage is easily compensated, since the energy stored in the primary side capacitor is fed to the load at instantaneous service interruption.
[0124] The manufacturing costs of the switching power supply are reduced, since a high-speed reverse-recovery diode is used on the primary side of the transformer and, therefore, general low-speed diodes are satisfactorily employable to the rectifier.
[0125] The power factor is improved, since the input current is made flow as far as the switching power supply is operating. And, the output voltage is compensated easily at instantaneous service interruption, since it is possible for the voltage of the electrolytic capacitor to exceed the peak value of the input voltage.
[0126] The switching power supply may be used for a longer period of time, since the driving electric power in the waiting mode is small due to the small rated values of the auxiliary switch and, therefore, the power consumption is reduced. Therefore, it is possible to meet the power consumption regulations for the TV sets and such instruments.
[0127] It is not necessary to install any additional switching power supply, the rated values thereof are {fraction (1/100)} as large as those of the main switching power supply. Therefore, a small, light-weight and low cost switching power supply is obtained.
[0128] The number of the packaging parts such as an insulative substrate is reduced, the dimensions of the package are minimized and the costs of the switching power supply are reduced, since the switch for the main power supply, the control IC for controlling the switch for the main power supply, the switch for the sub power supply and the control IC for controlling the switch for the sub power supply are installed on a common package. Moreover, the common control IC that controls the switches for the main power supply and the sub power supply facilitates further down-sizing and cost reduction.
[0129] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A switching power supply uses zero-current and zero-voltage switching to reduce switching noise. A main switch and an auxiliary switch channel current and voltage between various component paths to maintain a DC output voltage while switching at zero-current or zero-voltage states. Switch ON-OFF time ratios are controlled with a simple scheme to improve the circuit power factor. The switching rate is set to arbitrary frequencies, with switch ON time and OFF time being controlled independently. Conventional losses in efficiency when driving a load substantially less than the rated load are avoided. The switches and control functions can be implemented on an integrated circuit, reducing size and improving efficiency. Thus a flexible, simple design improves efficiency while reducing noise and manufacturing costs.
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BACKGROUND OF THE INVENTION
The invention relates to apparatus for the take-up and the storage of thread bundles, produced from high-polymer spinning materials. The threads emerge from a serial arrangement of spinnerets, are solidified by an air blast and drawn off continuously downwards, one bundle from each spinneret. The kind of storage depends upon the reprocessing of the thread bundles to the desired intermediate or end product. If filament yarn is to be produced from the thread bundles, the thread bundle extruded from each spinneret is usually drawn off by means of an arrangement of godets mounted on the take-up machine, moistened and/or treated with a liquid finish and wound up for storage. Starting from the bobbin, the thread bundle is then stretched and, for yarn production, possibly textured and drawtextured.
If, however, the thread bundles are to be reprocessed to staple fibers or fiber yarn, it is customary to draw off first the single thread bundles separately and to apply a finish. After the take-up on the take-up machine, the direction of the bundles is changed from vertical to horizontal and they are combined with correspondingly treated fiber bundles to provide a thread strand which is drawn off laterally by rollers and deposited for storage in a can. Then, the thread strands are continuously drawn off upwards from a plurality of filled cans and combined to a thread tow which is stretched, crimped, dried and possibly heat-set. The two may be intermediately deposited in containers or cut direct to staple fibers which generally are pressed subsequently to bales from which, finally, the fiber yarn is spun.
For the two process operations described above in principle differently designed units and combinations of units, i.e., production plants are employed, according to the present art. They include, as a rule, not only the spinning units, to which the high-polymer melt (coming direct from the polymerization stage or from molten chips by means of an extruder) is fed, but also blow ducts, spinning ducts and finally the special take-up machines having specific devices for storage depending on the end product. The storage devices may then be followed by reprocessing units.
These specialized process operations require that a complete production plant be shut down every time there is no market demand for the one or the other product, i.e., for filament yarn or fiber yarn. And the market demand is exceedingly difficult to predict for certain man-made spinning materials, for instance, polyamide yarns for carpet manufacture.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a process and an apparatus for its performance which permit flexibility in meeting specific production requirements in filament yarns or fiber yarns, using essentially the same equipment.
This object is achieved starting from the process previously mentioned by taking-up the thread bundles as single bundles per spinneret on bobbins, and/or by depositing them as a combined thread strand from a plurality of spinnerets in cans.
According to the basic concept of the invention, the thread bundles are taken up from the same spinning unit, possibly after a simple spinneret exchange, and passed to the appropriate storage. It is possible (a) to deposit the thread bundles of all spinnerets in the form of a thread strand for staple fiber and fiber yarn production in cans, or (b) to take up the thread bundles from all spinnerets for filament yarn production on bobbins, or (c) to combine the thread bundles partially to a thread strand and to take them up partially on bobbins. This results in a remarkable adaptability of the production plant to market requirements.
The fibers in the thread bundles to be taken up and stored on bobbins may be oriented to a higher or lower degree with respect to the position of the macromolecules in the single fiber capillaries, depending upon the take-up speed rate. The thread bundles may also be completely oriented by providing a preliminary stretching between rollers. Also, it is possible first to stretch and then to texture the thread bundles before winding them on bobbins. Another possibility is to wind one or several thread bundles per spinning position, on one or several winding spindles. Finally, the thread bundles from each spinning position (spinneret) may be deposited in small cans.
The apparatus of the invention comprises spinnerets aligned in one or several parallel rows, blow ducts arranged in a row below the spinnerets, and, connected to the blow ducts, spinning ducts which end just above an elongated take-up machine aligned and centered with respect to the row of spinnerets. The apparatus is characterized in that the take-up machine is equipped, on the one side, with a row of winding devices and, on the other side, with a row of two combining rollers, and is mounted approximately with its longitudinal center line below the center of the spinning line, and the spinning ducts are designed to follow the thread path to both sides of the take-up machine.
A feature of the apparatus according to the invention is the double-sided design of the take-up machine, its one side being designed for the take-up and the storage of thread on bobbins and its other side for the take-up and storage in the can piler. Either side may be operated separately or jointly with the other depending upon the desired intermediate or end product. If it is intended to wind on bobbins and to deliver into cans at the same time, the quantitative proportions are variable by regulating the distribution of the thread bundles to the respective sides of the take-up machine.
The term `spinning line` is defined as the imaginary connecting line between the centers of the blow duct outlet openings or the equivalent imaginary connecting line between the centers of the spinnerets.
Since the thread bundles, as they are drawn off to the one or the other side of the take-up machine, are diverted laterally from the vertical, the design of the spinning duct must take into account the variable thread path. For this purpose, it is proposed in one embodiment of the apparatus that the side walls of the spinning ducts diverge outwardly towards the lower end, thus corresponding to the split thread path. Also, that the lower ends of the spinning ducts, except for two lateral passage openings for the thread bundles, be closed by end plates. This spinning duct is broad enough to cover both branches of the thread path.
To facilitate handling the threads during the start-up procedure for spinning, it is advisable to provide flaps, slide valves or the like, in the end plates for enlarging the passage openings.
If the thread bundles all pass to the one side of the take-up machine, it is advantageous in this embodiment to avoid a large central dead space which might cause thread disturbing effects during start of spinning and during operation. This is accomplished by providing at the lower end of each spinning duct a hinged flap covering the width of the duct and projecting upwards into the duct. The flap may be rested against the one or the other of the diverging side walls to control the flow of air.
In a further embodiment of the apparatus, it is proposed that the spinning ducts at their lower ends split into branch pipes in an inverted Y configuration. With this arrangement, the upper part of the spinning duct is common to both thread path directions whereas, in the lower part, a pipe leg is provided for each of the two thread paths.
With this embodiment, too, it is advantageous to provide a hinged flap at the branch covering the duct width and projecting upwards into the spinning duct, which may rest against the one or the other of the side walls of the upper part of the spinning duct to block air flow.
In a further embodiment of the invention, each of the spinning ducts are hinged to the lower end of the corresponding blow duct as a swing pipe. In this embodiment, the thread path within each spinning duct may lead only to the one or the other side of the take-up machine. In the prior embodiments, however, the thread path may lead simultaneously to both sides of the take-up machine.
The deflection required for the diversion of the threads out of the vertical path may be provided thread guides disposed in the thread path between the spinnerets and the take-up machine. Suitably, these thread guides are arranged at the lower end of the blow duct. It is feasible to do without thread guides providing the air flow conditions in the blow duct are selected so that the thread adopts a free course without any contact occurring with the walls of the blow duct or the spinning duct.
DESCRIPTION OF THE DRAWINGS
The invention is described in detail hereunder with the aid of the schematic drawings illustrating the embodiment examples of the apparatus according to the invention, in which
FIG. 1 is a vertical section through a spinning plant, showing one spinning unit,
FIG. 2 is a side view, partially broken away, of the can piler side of the take-up machine,
FIG. 3 is a plan view of the machine shown in FIG. 2, with can storage on one side and bobbin storage on the other,
FIGS. 4 through 6 are sectional views of embodiments of the spinning duct differing from FIG. 1, and
FIGS. 7 and 8 show the arrangement of thread guides at the lower end of the blow duct shown in profile.
DETAILED DESCRIPTION
In the upper half of FIG. 1, one spinning position of a series of multiposition spinning manifolds 1 is shown. The high-polymer melt coming either from the end reactor of a polymerization and polycondensation plant or from a melting extruder, is passed through the tube 2 to the spinning manifold and distributed through pipe-lines (not shown) to the individual spinning positions. In each spinning position a spinning pump 4, positively connected to a drive 3, conveys the melt to a spinneret block 5 from which the spinning melt emerges downwards through one or several spinnerets (not shown) in the shape of a plurality of single threads. The spinnerets are aligned in a row, each producing a bundle of threads. The course of the thread bundles, the so-called thread path 6, is marked in FIG. 1 by broken lines and in the FIGS. 4 through 8 by dash-dotted lines. In their descent, the threads are exposed to conditioned air blowing across the path 6 of the threads, and thereby causing them more rapidly to solidify and cool. The air blast is fed to the blow duct 7 from a pressure chamber 8, which is limited at the top and the bottom by floor ceilings 9 and 10, respectively, passing through opening 11 under volume control 12. The air enters the thread area 14 of the blow duct 7 through directing vanes 13 and leaves the duct, after passing through the thread bundle, by a door 14' from where it flows as exhaust air into the spinning room 47. The reference number 48 designates a suction unit for vapours accumulating during the spinning procedure. The threads are shifted, owing to the air blast and depending on the blast intensity, to a greater or lesser extent out of their vertical line of fall. The degree of displacement depends, apart from the blast intensity, upon the tractive force with which the threads are drawn off downwards. Since these factors are maintained as constant as possible, the thread bundle rests so to speak on an air cushion. The shape, which the thread bundle assumes in the longitudinal direction, depends substantially upon the distribution of intensity of the air blast, referred to as the air blast profile. The conditions are chosen in practice so that the threads leave the lower end of blow duct opening 15 (also the beginning of the spinning duct 16) approximately at its center.
The spinning ducts 16 for each spinneret pass through the floor ceiling 10 and end above the elongated take-up machine designated, in general, by 17. The position of the thread paths 6 and 6' in the spinning duct depends upon to which of the two sides of the take-up machine 17 the threads are drawn off. In the example according to FIG. 1 the devices for the take-up and the storage in the form of the can piler are on the left side, opposed to the direction of blast, whereas the devices for the take-up and the storage on bobbins are arranged on the right side of the take-up machine, in the direction of blast. This arrangement, however, is not imperative and may be just as well reversed providing the take-up machine 17 is aligned with and centered with respect to the spinnerets in the spinning line.
To illustrate the devices for producing thread strands and a thread tow, respectively, reference is made to the left lower half of FIG. 1 in connection with FIGS. 2 and 3. The devices for producing thread strands include a roll 18 for finishing the thread bundle, a preceding diverting thread guide 19, and combining rollers 20 serving to change the direction of the thread bundles and to combine them to a thread strand 21. Instead of the combining rollers 20, stationary or rotating pins or a row of pins may also be provided. The thread strand 21 is then drawn off by the roller frame 22, passed to a pair of reels 23 and delivered by the latter into the can 24 (FIG. 2). An additional finish may be applied by means of a roller 25 prior to depositing the thread strand.
The drawing-off from, and the depositing in cans may take place, as shown in FIGS. 2 and 3, in two directions, in which case two thread strands 21 and 21' are formed. The arrangement is mirror-symmetrical, as illustrated in FIGS. 2 and 3. The dimension T shown on FIG. 2 between two neighboring thread paths 6 is the gauge of the spinning section and indicates the distance between the single spinning positions, the blow ducts and the spinning ducts, as well as the corresponding devices on the take-up machine 17. The number of the spinning positions which are allotted to one can piler, may be definitely prefixed, that is, divided in halves or unequally, but it may also be variable in that the total of the combining rollers 20 and 20' may be variable with respect to their position and direction of rotation so that they divert the thread strand into the opposite direction to the position 20" marked in FIG. 2 by broken lines. The same applies analogously to other means of diverting and combination not illustrated in the figures, but mentioned above.
The devices for the winding of the thread bundles include rolls 26 for the moistening and oiling of the thread bundles, (which rolls may be preceded by diverting thread guides 27) and one or several draw-off godets 28, as well as winding devices, marked in general by the reference number 29, by means of which the thread bundles are cross-wound into bobbins 30. Such winding devices may comprise a winding spindle driven directly by motor power or indirectly through friction pulley. It is also possible to provide several winding devices for each spinning position. Each winding device may wind up one or several thread bundles. The thread bundles may also be drawn off directly by the bobbins themselves. In this case, no draw-off godets need be provided.
The production from the spinneret block 5 may be distributed so that the total capacity is directed to one side of the take-up machine 17 to produce thread strands or alternately to the other side to produce bobbins. Or the spinning material produced may be provided and a portion passed to the one side of the take-up machine 17 for making thread strands and another portion to the other side for making bobbins. In this way, high flexibility of the plant is ensured.
As shown in FIG. 1, the alternative guidance of the thread bundles to the right or left side of the take-up machine 17 is achieved with the help of a common spinning duct 16, the side walls 31 and 32 of which diverge from each other towards the lower end to provide thread-path straddling. The lower end of the spinning duct 16 is partially closed by the end plate 33 leaving passage openings 34 on either side for the thread bundles.
Flaps or slide valves (not shown) may be installed in the end plate 33 to enlarge openings 34 at the beginning of the spinning operation.
The bringing-down of the thread end during starting of spinning is achieved, as a rule, through gravity. The starting of spinning may be facilitated by providing a down current of air in the spinning duct 16. This is very easily achieved providing the spinning room 47 has a higher static pressure than the take-up room, i.e., the room in which the take-up machine 17 is set up. Hence air flows from the spinning room and blast air from the thread area 14 of the blow duct 7 through the spinning duct 16 and emerges from the passage openings 34. During the stringing-up of the threads, the flaps or slide valves in plate 33 are closed so that only the passage openings 34 remain, with a cross section large enough for the passage of the thread bundles. During this operation exchange of large volumes of air between the mentioned rooms of different static pressures is undesirable.
The spinning duct 16 shown in FIG. 1 has a comparatively large central dead space between the thread paths 6 and 6' which also may have disturbing effects during starting of spinning, and during operation. The embodiments shown in FIGS. 4 through 8 avoid the formation of a larger central dead space.
In the spinning duct 16 shown in FIG. 4 at the lower end, the flap 35, covering the duct width and projecting upwards, is hinged at 36. The actuation of the flap 35 is easily effected from the take-up room with the help of a lever 37. Depending on its position the flap 35 shuts off the dead spaces 38 or 38' and thereby facilitates the starting of spinning by preventing disturbing air turbulences.
The same effect is achieved by the embodiment shown in FIG. 5. In this case, the spinning duct 39 branches at its lower end into pipes 40 and 41 to form an inverted Y configuration fork, a flap 43 projecting upwards is hinged at 42. The flap 43 in this embodiment is suitably actuated (not shown) from the spinning room.
Finally, the spinning duct may consist, as shown in FIG. 6, of a single comparatively narrow swing pipe which is hinged at 45, at the lower end of the blow duct 7. With this moving embodiment, care must be taken that a tight seal of the spinning duct is achieved where it passes through the floor-ceilings.
The thread path between spinneret and take-up machine may be stabilized by interposed thread guides. In the examples of embodiments shown in FIGS. 7 and 8, the thread guides 46 and 46', respectively are arranged at the lower end of the blow duct 7, directly before the diverting of the thread bundle to the one or the other thread path in the spinning duct. Depending upon whether thread path is led to the one or the other side of the take-up machine 17, the thread guide is mounted on the one or the other side of the thread path as it is evident from the FIGS. 7 and 8. The thread guide 46, 46' may be constructed in different ways. By way of example, it may be made from metal, glass, ceramic and other material. It may also be used for moistening and finishing of the thread bundles by making it hollow and providing outlet openings for liquid. In the embodiment shown, it consists of a smooth bar. For the spinning of several thread bundles it may be composed of several sections to form a slotted thread guide.
It is to be understood that the embodiment of the invention which has been described is merely illustrative of one application of the principles of the invention. Numerous modifications may be made to the disclosed embodiment without departing from the true spirit and scope of the invention.
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A flexible apparatus and method for producing synthetic fibers in either the form of a single thread bundle on a bobbin, or as a combined thread strand in a storage can, without rearranging the spinning plant. This is accomplished by extruding the threads, one bundle from each of a series of aligned spinnerets, downwardly through ducts carrying a stream of air, and mounting directly beneath the ducts, in alignment therewith, an elongated take-up machine. The take-up machine has a row of winding devices on one side and a row of combining rollers on the other. The thread bundle from each spinneret is directed through a duct arrangement either to one side or the other of the take-up machine. All spinnerets may feed one side, or the other, or the production can be mixed with some spinnerets feeding one side and some the other, depending upon whether the market demand is for filament yarns or staple fibers.
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This application is a continuation of U.S. patent application Ser. No. 12/597,977 filed on Apr. 6, 2010, now U.S. Pat. No. 8,571,797.
TECHNICAL FIELD
The present invention relates in general to the field of measuring properties of downhole environments and, more specifically, to resistivity tool analysis.
BACKGROUND
Resistivity tools are used in the oil and gas industry to determine the resistivity of earth formations surrounding a borehole. Conventional induction tools, for example, work by using a transmitting coil (transmitter) to set up an alternating magnetic field in the earth formations. This alternating magnetic field induces eddy currents in the formations. One or more receiving coils (receivers), disposed at a distance from the transmitter, detect the current flowing in the earth formation. The magnitudes of the received signals are proportional to the formation conductivity. Therefore, formation conductivities may be derived from the received signals.
However, the existence of a borehole complicates the derivation of formation conductivity from the received signals. The most prevalent complication that affects the derivation of formation conductivity from the received signals arises from the presence of drilling fluids in the borehole surrounding the induction instrument. This is referred to generally as the borehole effects. Often, the fluids in the borehole (drilling mud) are made very saline, thus conductive, as part of the drilling practice. The conductive drilling muds can contribute a significant proportion of the received signals and, therefore, should be carefully removed.
In addition, tool properties may affect the measurements conductivity tensor. The effects of the borehole and tool properties on the measured conductivity tensor may be very significant, even in a highly resistive, oil base mud (OBM) environment. Unless the borehole/tool effects are removed or otherwise compensated for, it is hard to use or interpret the measurements to infer formation properties.
SUMMARY
A method for correcting formation properties due to effects of a borehole is disclosed. The method includes obtaining voltage measurements using a logging tool disposed in a borehole penetrating a subsurface formation and using a processor to: determine a tensor for the formation using the voltage measurement, for a given set of parameters, determine, based upon the voltage measurements, a parameter value for each parameter in a subset of the set of parameters, compute a borehole-inclusive modeled tensor that includes the effects of the borehole using the parameter values, optimize the parameter values using the determined tensor and the borehole-inclusive tensor, compute an optimized tensor using the optimized parameter values, compute a borehole corrected tensor using the optimized tensor, and determine at least one borehole corrected formation property using at least one of the borehole corrected tensor or the optimized parameter values.
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
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:
FIGS. 1-1 and 1 - 2 are illustrations of a prior art tri-axial induction array and associated measurements at a given spacing.
FIG. 2 is an illustration of an eccentered tool in a borehole through an anisotropic formation at a relative dip angle.
FIG. 3 is a block diagram of an example of a borehole correction method within the scope of the present invention.
FIG. 4-1 (includes FIGS. 4 - 1 A- 4 - 1 I) shows modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is centered in the borehole.
FIG. 4-2 (includes FIGS. 4 - 2 A- 4 - 2 I) shows modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=0).
FIG. 4-3 (includes FIGS. 4 - 3 A- 4 - 3 I) shows modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=90).
FIG. 4-4 (includes FIGS. 4 - 4 A- 4 - 4 I) shows modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=180).
FIG. 4-5 (includes FIGS. 4 - 5 A- 4 - 5 I) shows modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool eccentered in the borehole (ψ=270).
FIG. 4-6 is a graph in which the estimated dip azimuth is plotted against the actual dip azimuth of the model for a centered tool.
FIG. 5-1 (includes FIGS. 5 - 1 A- 5 - 1 F) is a plot of the sum and difference of the off-diagonal pairs of modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is centered in the borehole.
FIG. 5-2 (includes FIGS. 5 - 2 A- 5 - 2 F) is a plot of the sum and difference of the off-diagonal pairs of modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=0).
FIG. 5-3 (includes FIGS. 5 - 3 A- 5 - 3 F) is a plot of the sum and difference of the off-diagonal pairs of modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=90).
FIG. 5-4 (includes FIGS. 5 - 4 A- 5 - 4 F) is a plot of the sum and difference of the off-diagonal pairs of modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=180).
FIG. 5-5 (includes FIGS. 5 - 5 A- 5 - 5 F) is a plot of the sum and difference of the off-diagonal pairs of modeled responses for various spacings in an OBM borehole passing through an anisotropic formation with dip and varying dip azimuth, and in which the tool is eccentered in the borehole (ψ=270).
FIG. 6-1 (includes FIGS. 6 - 1 A- 6 - 1 D) is a set of plots in which the estimated dip azimuth obtained using an embodiment of the present invention is plotted against the actual dip azimuth for four values ψ.
FIG. 6-2A shows a formation model and FIGS. 6 - 2 B- 6 - 2 J show the associated modeled responses of a tool passing through anisotropic beds having significant resistivity contrast with arbitrary dip and dip azimuth angles.
FIG. 6-3 is a plot showing the estimation of formation dip azimuth angle Φ from a tool passing through three anisotropic beds.
FIG. 7-1 is an illustration showing the parameters used to determine the tool eccentering azimuth angle.
FIG. 7-2 (includes FIGS. 7 - 2 A- 7 - 2 L) is a set of graphs showing the eccentering azimuth angles computed using model data for various tri-axial induction array spacings and dip azimuth equal to zero degrees.
FIG. 7-3 (includes FIGS. 7 - 3 A- 7 - 3 L) is a set of graphs showing the eccentering azimuth angles computed using model data for various tri-axial induction array spacings and dip azimuth equal to 90 degrees.
FIG. 7-4 (includes FIGS. 7 - 4 A- 7 - 4 L) is a set of graphs showing the eccentering azimuth angles computed using model data for various tri-axial induction array spacings and dip azimuth equal to 180 degrees.
FIG. 7-5 (includes FIGS. 7 - 5 A- 7 - 5 L) is a set of graphs showing the eccentering azimuth angles computed using model data for various tri-axial induction array spacings and dip azimuth equal to 270 degrees.
FIG. 8-1 is a plot showing, for a 15 inch array spacing, the σxz-σzx and σzz responses as functions of σh, σh/σv, and dip angle. The σxz-σzx are plotted as solid lines and σzz are plotted as dots.
FIG. 8-2 is a graph of σxz-σxz as function of eccentering distance for an OBM borehole through an anisotropic formation with arbitrary dip and azimuth.
FIG. 9 is a flow chart of an example method of estimating horizontal resistivity and eccentering distance within the scope of the present invention.
FIG. 10 is a flow chart of an example method of determining the formation azimuth angle and the tool eccentering azimuthal angle within the scope of the present invention.
FIG. 11 is a block diagram of an example of a forward engine that may be used in a borehole correction method within the scope of the present invention.
FIG. 12-1 (includes FIGS. 12 - 1 A- 12 - 1 I) are example comparisons between conductivity tensors from a forward engine versus independently modeled conductivity tensors for all 6 tri-axial measurement spacings from 15 inches to 72 inches as a function of 1/Rh (SIGh). The values of the model parameters used in this example are all at the middle of the grid point of the borehole correction (BHC) database.
FIG. 12-2 (includes FIGS. 12 - 2 A- 12 - 2 I) are example comparisons between conductivity tensors from a forward engine versus independently modeled conductivity tensors for all 6 tri-axial measurement spacings from 15 inches to 72 inches as the formation dip azimuthal angle (AZ) varies from 0 to 360 degree in steps of 11.25 degrees. The tool is eccentered by 3-inch in the direction 30 degrees from the borehole x-axis direction.
FIGS. 12 - 3 A- 12 - 3 D graphically illustrate examples of statistics of the interpolation errors of the forward engine from about 1000 test cases with off-grid model parameter values: FIG. 12-3A is the XX component from 15 inch, 27 inch, and 54 inch spacings; FIG. 12-3B is the YY component from 15 inch, 27 inch, and 54 inch spacings; FIG. 12-3C is the ZZ component from 15 inch, 27 inch, and 54 inch spacings; and FIG. 12-3D is the XZ component from 15 inch, 27 inch, and 54 inch spacings.
FIG. 13 is a block diagram of an example of an iterative minimization inversion process that may be used within the method of the present invention.
FIG. 14-1 (includes FIGS. 14 - 1 A- 14 - 1 C) illustrates examples of borehole correction processing results using off-grid noiseless theoretical model data. The borehole correction outputs are compared with the known model parameter results. FIG. 14-1A is for Rh and Rv. FIG. 14-1B is for dip angle and decc. FIG. 14-1C is for formation azimuth (AZF) and tool eccentering azimuth (AZT).
FIG. 14-2 (includes FIGS. 14 - 2 A- 14 - 2 C) illustrates examples of borehole correction processing results using off-grid theoretical model data with simulated random noise added. The borehole correction outputs are compared with the known model parameter results. FIG. 14-2A shows Rh and Rv. FIG. 14-2B shows dip angle and decc. FIG. 14-2C shows formation azimuth (AZF) and tool eccentering azimuth (AZT).
DETAILED DESCRIPTION
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.
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.
FIG. 1-1 is an example of a 3D tri-axial induction tool, indicated generally by numeral 10 , comprising transmitter 12 , balancing receiver 14 and main receiver 16 , wherein the antennas are represented by their respective dipole moments. A 3D tri-axial induction tool measures voltages from which a nine component apparent conductivity tensor (σm(j, k), j, k=1, 2, 3) at a given transmitter/receiver spacing, may be obtained. The indices j and k represent the transmitter and receiver orientations, respectively. For example, j=1, 2, 3 corresponds to the transmitter coil orientation in the x, y, z, directions, respectively. Different tensors may be obtained for different transmitter/receiver spacings, and different spacings may be identified herein using the subscript i.
FIG. 1-2 shows an example of a tri-axial measurement matrix, wherein the first subscript corresponds to the transmitter orientation and the second subscript corresponds to the receiver orientation. These measurements are usually obtained in frequency domain by firing the transmitter with a continuous wave (CW) of a given frequency to enhance the signal-to-noise ratio. However, measurements of the same information content could also be obtained and used from time domain signals through a Fourier decomposition process e.g., frequency-time duality. Formation properties, such as horizontal and vertical conductivities (σh, σv), relative dip angle (θ) and the dip azimuthal angle (Φ), as well as borehole/tool properties, such as mud conductivity (σ mud), hole diameter (hd), tool eccentering distance (decc), tool eccentering azimuthal angle (ψ), all affect these conductivity tensors.
FIG. 2 illustrates an example of eccentered tool 10 in a borehole 20 through an anisotropic formation 22 with a dip angle. Using a simplified model of layered anisotropic formation traversed obliquely by a borehole, the response of the conductivity tensors depends on the above 8 parameters (σh, σv, θ, Φ, σmud, hd, decc, ψ) in a complex manner. The effects of the borehole/tool to the measured conductivity tensors may be very large even in oil base mud (OBM) environment. Without removing the borehole/tool effects, it may be difficult to use or interpret the measurements to determine formation properties. An embodiment of the presently disclosed method allows for an estimate of formation parameters (σh, σv, θ, and Φ) in substantially real-time. The borehole correction method accounts for the effects of the borehole filled with OBM and the tool 10 being eccentered in the borehole 20 at an arbitrary eccentering distance and eccentering azimuth (decc, ψ). The borehole correction method removes the effects of the borehole and/or tool from the raw conductivity tensor measurements and yields a “borehole corrected” conductivity tensor (σbhc).
One method to account for the effects of the borehole and tool and obtain the formation properties (σh, σv, θ, Φ) from the measured apparent conductivity tensors is multi-dimensional parametric inversion, to search for values of formation/borehole parameters that best match the model responses to the measured ones. Because the presently disclosed system and method effectively reduces the number of free parameters that must be inverted, time and resource savings are had because there is no need to invert for 8 free parameters at every frame of the log data.
FIG. 3 is a block diagram of an example of a borehole correction method of the present invention, generally indicated by the numeral 30 . The inputs 32 include the measured conductivity tensor, σ m , which may be pre-rotated to certain reference frame, such as top-of-the-hole (TOH) or north (NAZ). The pre-rotation will make the output azimuthal angles (Φ and ψ) referenced to a stationary reference frame to facilitate interpretation. Other inputs 32 include hole diameter (hd) and standard deviation of the sonde error measurements, σ std , which are used to set the weights, w i,j,k , in the inversion and also used in estimation of the inversion accuracy. The hole diameter (hd) inversion may not be needed where a caliper measurement is available. In case the caliper measurement is not available, the method may be adjusted to invert for one more free parameter, the hole diameter (hd) (which may incur a slightly higher computational cost).
In step 34 the formation dip azimuth (Φ) and the tool eccentering azimuth (ψ) are estimated directly from the measured apparent conductivity tensor. Step 38 estimates a set of initial guesses for the remaining model parameters including σ h , σ v , θ, decc, which are needed in the final inversion. For the case of OBM with hd given by a caliper measurement, the method reduces the eight (free) parameter inversion to four (σ h , σ v , θ, decc) (free) parameters. This reduction in free parameters makes the inversion robust and practical. In step 36 the tool responses are determined using a forward engine. A simplified model is described with reference to FIG. 2 . A robust initial guess parameter set is provided in step 38 . Step 40 is an iterative process of inverting for the free parameters by searching for the minimum of a cost function, which is designed to have a minimum when the model responses (e.g., from pre-computed borehole model database 48 ) match the measured responses. In step 42 the errors of the inverted parameters, based on the sensitivity function determined from the model, are estimated. The accuracy estimates will be used for quality control purposes to help interpret the inverted answers. In step 44 the borehole effect and the borehole corrected signals are determined. The borehole effect is the difference between the apparent conductivity tensors obtained from the model in FIG. 2 and a model with the same formation but no borehole. The borehole effects will be subtracted from the originally measured apparent conductivity tensor to obtain the borehole corrected measurements.
The outputs 46 of borehole correction method 30 may include certain inverted model parameters (e.g., horizontal conductivity (Rhi), vertical conductivity (Rvi), relative dip angle (Dipi) and tool eccentering distance (decci)), the accuracy estimates of those four inverted parameters (ΔP n , n=1, . . . , 4), the formation dip and tool eccentering azimuthal angles (Φ and ψ), and the borehole corrected conductivity tensor (σbhc). If hole diameter is not known, the inverted borehole diameter (hdi) will also be included in the outputs 46 .
1. Borehole Correction Method
1.1 Estimation of Formation Dip Azimuth (Φ) and Tool Eccentering Distance (decc) and Azimuth (ψ)
FIGS. 4-1 through 4 - 5 show examples of model responses obtained using a 3-dimensional finite-element method for 15 inch through 72 inch array spacings of the tool in an 8-inch diameter OBM filled borehole through an anisotropic formation (R h =1, R v =10 ohm-m) with a 50 degree dip and varying azimuth from 0 to 360 degrees. The computed conductivity tensor components for the centered case and the four eccentered cases with the center of the tool located 2 inches from the center of the borehole in the x-axis (ψ=0), negative y-axis (ψ=90), negative x-axis (ψ=180), and y-axis (ψ=270) directions are shown.
For the centered case ( FIG. 4-1 ), σ xx can be described by A+B*cos(2 Φ), where A and B depend on σ h , σ v , and θ. The σ yy is a 90 degree shifted version of σ xx . The σ zz response is practically independent of Φ. For the off-diagonal term, the symmetry of the problem requires σ xy =σ yx , σ xz =σ zx , σ yz =σ zy . Furthermore, σ xy can be described by C*sin(2 Φ), where C depends on σ h , σ v , and θ. The term σ xz can be described by D*cos(Φ) where D depends on σ h , σ v , and θ. The σ yz is a 90 degree shifted version of σ xz .
Based on the above observations, the estimate for the formation dip azimuth, Φ, for the centered case, may be expressed as:
Φ=atan2(σ yz , σ xz ) Eq. (1)
where atan 2 denotes the four-quadrant inverse tangent (arctangent) of the real parts of σ yz and σ xz . If the atan 2 function returns a negative value for Φ, Φ is set to Φ+360. The results of the estimated formation azimuth from Eq. (1) using the centered case data shown in FIG. 4-1 are shown in FIG. 4-6 , indicating very good agreement.
For the examples of eccentered tool positions ( FIG. 4-2 through 4 - 5 ), the conductivity tensor appears to be much more complicated than the centered ease. Most of the simple symmetric properties such as those described by A+B*cos(2 Φ), C*sin(2 Φ) and D*cos(Φ) no longer exist. Depending on the tool position in the borehole, the symmetry of off-diagonal terms cannot be guaranteed, that is, in general, σxy≠σyx, σxz≠σzx, σyz≠σzy. It appears that the σ xx and σ yy components are almost independent of the tool position in the borehole while σ zz has a slight dependency on the tool position. This dependency decreases as the array spacing increases. The eccentering introduces significant complexity in the off-diagonal components. The methods disclosed herein show how to solve for Φ and ψ from the measured conductivity tensor for the general case of eccentered tool in a borehole. Theses methods therefore reduce two of the dimensions from the multi-dimensional inversion problem and greatly enhance the robustness of the inversion. These methods can also be used independently to obtain formation dip azimuth Φ and tool eccentering azimuth ψ from the measured conductivity tensor.
Eccentered data can be viewed in a different manner such that the complexity associated with eccentered positioning is reduced. Shown in FIG. 5-1 through 5 - 5 are the sums and differences of the off-diagonal pairs of the conductivity tensor, σxy±σyx, σxz±σzx, σzx±σzy, for the centered case and the four eccentered cases, respectively.
The sum terms, σxy+σyx, σxz+σzx, σyz+σzy, are practically independent of the tool position in the borehole. This observation is supported by the fact that the sum terms (FIGS. “D”, “E”, and “F” of FIGS. 5-1 through 5 - 5 ) for the centered case and 2-inch eccentered cases with eccentering azimuth ψ=0, 90, 180, and 270 degrees are essentially the same. The formation dip azimuth (Φ) information in the σxz+σzx, σyz+σzy terms are substantially free from the interference of the eccentering tool position in the borehole. For the general eccentering case, the system can obtain the formation dip azimuth from the following equation:
Φ=atan2(σ yz +σ zy , σ xz +σ zx ) Eq. (2)
Shown in FIG. 6-1 are examples of formation dip azimuth estimation using Eq. (2) with model data where the tool is eccentered in the borehole at four different positions. The results are robust, accurate and substantially independent of the tool eccentering position.
The azimuth estimation from Eq. (2) is substantially independent of bed boundary also. FIG. 6-2A shows a 3-bed model formation. In this example, the tool traverses the formation with relative dip and azimuth angles of 55 and 292.5 degrees, respectively. The first bed 60 is quite conductive with R h =1 ohm-m, and R v =2 ohm-m. The second bed 62 has resistivities R h =10 ohm-m, R v =100 ohm-m. The third bed 64 is conductive, having a higher anisotropy ratio than the first bed 60 .
The nine components of the apparent conductivity tensor are plotted in FIGS. 6-2B through 6 - 2 J. The estimated formation dip azimuths determined from this model data set using Eq. (2) are shown in FIG. 6-3 . The estimations are accurate to within the computer rounding error throughout the entire log. All the spacings yield substantially similar results.
Using model data, the results in FIG. 6-1 are substantially the same for all the array spacings. In certain logging conditions, however, results from one array spacing may differ from other array spacings because each array may have different noise and calibration errors. Sometimes the downhole conditions may adversely affect one array more than the others. Therefore, the final formation azimuth estimation Φ f may be derived from some statistical operation of Φ from all the arrays to obtain the benefit of averaging or weeding out outliers. Some common statistical operations for this purpose are described in the following example.
Let Φi be the formation azimuth estimation from the i-th array spacing, i=1, 2 . . . , N. The weighted average solution from all the spacings is given as
Φ f = atan 2 ( ∑ i = 1 N W i * sin ( Φ i ) , ∑ i = 1 N W i * cos ( Φ i ) ) . Eq . ( 3 )
If Φ f is less than zero, then Φ f =Φ f +360. Wi is the weighting function for the i-th spacing.
An example of a median method that screens out outliers is described below. Let [s 1 , s 2 , . . . , sn]=SORT([sin(Φi), i=1, . . ., N]) be the sorted (either ascending or descending order) values of the sine of formation azimuthal angle estimations from any selected group of array spacings. Similarly, let [c 1 , c 2 , . . . , cn]=SORT([cost(Φi), i=1, . . . , N]) be the sorted cosine values in the same ascending or descending order.
Φ f =atan2([ s n/2 +s n/2+1 ], [c n/2 +c n/2+1 ]), if N is even
Φ f =atan2( s (n+1)/2 , c (n+1)/2 ), if N is odd. Eq. (4)
The vector averaging formulation, in Eqs (3) and (4), substantially avoids the phase wrapping problem.
The Φ f obtained from Eqs. (2), (3), or (4) is referenced to the tool x-axis. During logging, the tool may spin in the borehole in an unpredictable fashion. Thus, it is desirable to reference the formation azimuth angle relative to the borehole coordinate system. This can be accomplished by a pre-processing step which will rotate the measured conductivity tensor around the z-axis so that the tool x-axis is in the same direction as the borehole x-axis, which may be in the top-of-the-hole (TOH) direction or north direction. The rotating angle usually comes from a measurement of the relative orientation between the tool and the borehole. Equations (2), (3), and (4) can be used on the rotated data to invert for the formation dip azimuth relative to the coordinate system fixed to the borehole.
The tool eccentering azimuth (Ψ) information are contained in the difference terms, σxy−σyx, σxz−σzx, σyz−σzy. However, the magnitude of the response to the eccentering may be significantly different for the three difference terms. For example, the most response may come from the σxz−σzx, σyz−σzy terms and the least response may come from the σxy−σyx term. For the example in FIG. 5-2 (decc=2 inches and Ψ=0 deg.), the magnitude of the tool eccentering response in the σxz−σzx term is about 500 mS/m at the 15 inch spacing and this magnitude is relatively constant as the formation azimuth varies. The magnitude of the eccentering response decreases as the array spacing increases, e.g., shorter array spacings can “see” the effect of the borehole more clearly. At 54 inch and 72 inch spacings, the eccentering response is reduced to about 100 and 65 mS/m, respectively.
The responses of σxz−σzx and σyz−σzy are coupled tightly to the tool eccentering azimuth angle Ψ. The definition of Ψ is the angle spanned between the x-axis of the borehole coordinates and the line from the center of the borehole 20 to the center of the tool 10 in the counter-clockwise direction. FIG. 7-1 shows five tool positions 10 a - 10 e in the borehole with Ψ=0, 90, 180, 270, and an arbitrary angle, respectively. The σxz−σzx and σyz−σzy responses of the first four positions are shown in FIGS. “A”, “B”, and “C” of FIGS. 5-2 through 5 - 5 , respectively. At the Ψ=0 position, σxz−σzx is negative, but its magnitude is large compared with σyz−σzy. At the Ψ=90 position, the σxz−σzx response becomes very small and σyz−σzy become very large, but positive. At the Ψ=180 position, σxz−σzx is positive and very large while σyz−σzy becomes small. Finally, at the Ψ=270 position, σxz−σzx becomes very small and σyz−σzy turns into very large negative value. Based on the foregoing, the following examples of methods for estimating the tool eccentering azimuth angle Ψ are provided.
De-spinning—Rotate the conductivity tensor (in tool's coordinate system) around the z-axis so that the x-axis points in the same direction as the borehole's x-axis. This de-spinning step provides a borehole-based reference for measuring the relative position of the tool in the borehole. The rotation may be expressed as:
σ ds = R σ m R T , σ m = [ σ xx σ yx σ zx σ xy σ yy σ zy σ xz σ yz σ zz ] ,
R = [ cos ( ϕ ) sin ( ϕ ) 0 - sin ( ϕ ) cos ( ϕ ) 0 0 0 1 ] , Eq . ( 5 )
where σ m is the measured apparent conductivity tensor, σ ds is the de-spinned conductivity tensor, R is the de-spinning matrix with rotation angle φ, and R T is the transpose of R. Rotate the σ ds tensor using Eq. (5) such that σxz−σzx attains its maximum value to determine the rotation angle φmax. The eccentering azimuth angle Ψ will be φmax.
In another point of view, σxz−σzx of the rotated σ ds tensor has a functional form of:
Y=A *cos(Ψ+φ) Eq. (6)
where φ is the rotation angle. Instead of searching for the maximum value, an alternative method includes the step of solving for Ψ directly by using the 90-degree rotated σ ds tensor value. The eccentering azimuth angle may be expressed as:
Ψ=atan2(−(σ xz −σ zx at φ=90), (σ xz − zx at φ=0)). Eq. (7)
Shown in FIGS. 7-2 through 7 - 5 are the results of estimating the tool eccentering azimuth angle, Ψ. To illustrate, FIG. 7-2B shows the computed difference σ xz −σ zx as a function of rotation angle φ for Ψ equal to 30 degrees. For a particular transmitter/receiver spacing, φmax can be read from the plot, which is seen to be 30 degrees, as expected. Different model data sets using four different formation azimuth angles demonstrate that the results are robust, accurate, and substantially independent of formation azimuth angle. FIG. 10 is a block diagram of an example of determining formation/tool eccentering azimuthal angles.
A very close estimation of tool eccentering distance (decc) can be obtained from the σxz−σzx and σzz terms. Comparing the examples shown in FIGS. 4-1 (centered case) and 4 - 2 (eccentered case), the eccentering distance (decc) has the biggest effect on the σ xz and σ zx components. For the centered case, σ xz =σ zx , the eccentering effectively lowers the σ xz and raises the σ zx responses with respect to the centered case. Therefore σ xz −σ zx is a very strong function of decc. In addition, σ xz −σ zx is also a strong function of σ h and a weak function of σ h /σ v and dip angle.
Shown in FIG. 8-1 are examples of σ xz −σ zx and σ zz responses in an 8-inch OMB borehole. FIG. 8-1 illustrates the sensitivity and functional form of σ xz −σ zx and σ zz to σh, σ h /σ v , and dip angle. In the log-log domain, the variation of σ xz −σ zx and σ zz as a function of σ h is nearly linear. Both σ xz −σ zx and σ zz are strong functions of σ h and weak functions of σ h /σ v and dip angle. The σ xz −σ zx response is nearly a linear function of the eccentering distance, decc, as shown in FIG. 8-2 . A plot of the least square fit line through the data is also shown. The mean deviation between the data and the least square fit line is relatively small.
An example of a method for estimating decc from σ xz −σ zx and σ zz measurements, based on the foregoing, may include the following steps:
a) Rotating the de-spinned conductivity tensor σ ds with an angle Ψ (see Eq. (5)) to align the x-axis in the direction of eccentering. b) Estimating the horizontal conductivity, σ h — i , from the zz component of the de-spinned conductivity tensor through interpolation, as indicated below:
σ h — i =interpolate (σ zz — c , σ hg , σ zz — m ), Eq. (8)
where σ zz — c , is a vector containing the average modeled σ zz over a wide range of σ v /σ h and dip angles (see FIG. 8-1 ). The σ hg is a vector containing the grid point values for the σ h . The σ zz — m is the zz component of the tensor σ ds after rotation. The tool in the model is eccentered by a distance decc_m in the x-direction, which is aligned with the borehole x-direction. The y i =interpolate (x, y, x i ) is a interpolation function that would find the value of y i corresponding to a given value of x i through interpolation between two vectors x and y. As shown in FIG. 8-1 , the interpolation may be done in the log-log domain. c) Determining the averaged model σ xz −σ zx response, xzmzx_m, at σ h — i through interpolation, as shown below:
xzmzx — m= interpolate (σ hg , xzmzx, σ h — i ). Eq. (9)
where xzmzx is a vector containing the average modeled σ xz −σ zx response over a wide range of σ v /σ h and dip angles (see FIG. 8-1 ). The tool in the model is eccentered by a distance decc_m in the x-direction, which is aligned with the borehole x-direction. The interpolation may be done in the log-log domain. d) Determining the estimated eccentering distance, decc_i, as:
decc — i =decc — m *( xzmzx — i/xzmzx — m ) Eq. (10)
where xzmzx_i is the σ xz −σ zx response of the de-spinned conductivity tensor σ ds after rotation from step (a) above.
FIG. 9 is a flow chart of an example of a method of estimating horizontal resistivity (Rh_i) and eccentering distance (decc_i).
1.2 Forward Engine Using Interpolation and Azimuthal Expansion
FIG. 11 is a block diagram representing an example of a forward engine and its interaction with other components shown in FIG. 3 . The responses for arbitrary values of the first 5 parameters (hd, decc, σh, σv, θ) at the three Φ values are computed through multi-dimensional interpolation. Next, an azimuthal expansion technique is used to compute the final response of the tool for arbitrary values of the seven model parameters (hd, decc, σh, σv, θ, Φ, ψ). The details of the azimuthal expansion are described below.
The responses of the tool in the model described in FIG. 2 are pre-computed via a finite element code for various model parameter values to form a multi-dimensional table. There are seven dimensions in this table corresponding to the seven model parameters in OBM (hd, decc, σh, σv, θ, Φ, ψ). Using conventional discretized grids to represent these seven model parameters over their expected range, a typical number of cases to be modeled for the complete table will be about 39,345,560. However, the computer time needed to generate more than 39 millions cases and the table size are impractical with conventional technology.
To reduce the size of this table, the presently disclosed azimuthal expansion technique (shown as block 34 of FIG. 3 ) expresses the response of the tool for arbitrary formation dip azimuth (Φ) and arbitrary tool eccentering azimuth (ψ) using only three data points for formation dip azimuth angle (Φ=0, 45, and 90 degrees), evaluated at the tool eccentering azimuth of zero degrees (ψ=0). Using azimuthal expansion, borehole correction method 30 may construct a 6-dimensional table for the first six model parameters (hd, decc, σh, σv, θ, Φ), all with ψ=0. The last dimension for the formation azimuth Φ may contain only three data points for Φ=0, 45, and 90.
The azimuthal expansion allows for computation of the borehole response relatively quickly (e.g., on the fly with analytic formula). Referring to the grid numbers mentioned above, the disclosed method may reduce the table size to about 91,080, or by a factor of 432, for example. By reducing the size of the table, azimuthal expansion 34 reduces the complexity and time required for the table computation. The reduced table size may also allow a relative increase in the speed of the borehole correction process.
The azimuthal expansion expresses the conductivity tensor σij, ij=1, 2, 3 (1 for x, 2 for y, and 3 for z) in terms of series expansion:
σ ij = A ij 0 + ∑ k = 1 n [ A ijk COS ( k Φ ) + B ijk SIN ( k Φ ) ] ,
where coefficients A ijk and B ijk depend on Ψ Eq . ( 11 ) A ijk = C ijk 0 + ∑ p = 1 m [ C ijkp COS ( p Ψ ) + D ijkp SIN ( p Ψ ) ]
B ijk = E ijk 0 + ∑ q = 1 l [ E ijkq COS ( q Ψ ) + F ijkq SIN ( q Ψ ) ] Eq . ( 12 )
where the coefficients C ijkp , D ijkp , E ijkq , and F ijkq are functions of other parameters (σ h , σ v , θ, σ m , hd, and decc).
The above series expansion may be simplified by limiting n, l, and m to less than or equal to 2. The following expressions use Φ=0, 45, and 90 degrees and ψ=0 to compute the nine components of the conductivity tensor. The three formation dip azimuth values and one eccentering azimuth value, however, are not necessarily limited to those values.
The σ xx term can be expressed as:
σxx=Axx+Bxx *COS(2 Φ) +Cxx *COS(2 ψ), Eq. (13)
where Axx, Bxx, and Cxx are constants determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ). Axx=0.5*[σxx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)+σyy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)] Bxx=σxx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σxx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0) Cxx=0.5*[σxx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σyy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)]
The σ yy term can be expressed as:
σ yy=Ayy+Byy *COS(2 Φ) +Cyy *COS(2 ψ), Eq. (14)
where Ayy, Byy and Cyy are constants determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ). Ayy=Axx, Cyy=−Cxx Byy=σyy(σh, σv, θ, Φ=0, σm, hd, decc, σ=0)−σyy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)
The σ zz term can be expressed as:
Azz 0 +Azz 2*COS(2 Φ) +Bzz 2*SIN(2 ψ), Eq. (15)
where Azz and Bzz are constants determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ); Azz 0 =σzz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0) Azz 2 =Czz 22 *COS(2 ψ) Czz 22 =[σzz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σzz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)] Bzz 2 =Dzz 22 *SIN(2 ψ) Dzz 22 =Czz 22
The σ zz term can be expressed as:
Axz 0 +Axz 1*COS(Φ) +Bxz 1*SIN(Φ) +Axz 2*COS(2 Φ) +Bxz 2*SIN(2 Φ) Eq. (16)
Axz 0 , Axz 1 , Axz 2 , Bxz 2 , and Bxz 2 are coefficients determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ); Axz 0 =0.5*Cxz 01 *COS(ψ) Axz 1 =0.5*[Cxz 10 +Cxz 12 *COS(2 ψ)] Axz 2 =0.5*[Cxz 21 *COS(ψ)+Cxz 23 *COS(3 ψ)] Bxz 1 =0.5*Fxz 12 *SIN(2 ψ) Bxz 2 =0.5*[Fxz 21 *SIN(ψ)+Fxz 23 *SIN(3 ψ)] Cxz 01 =σxz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0) Cxz 10 =0.5*[σyz(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)+σzy(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0) +σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)+σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Cxz 12 =−0.5*[σyz(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)+σzy(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)] −σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Cxz 21 =0.5*[σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0) −σxz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)+σzx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)] Cxz 23 =Cxz 21 Fxz 12 =Cxz 12 Fxz 21 =0.5*[σyz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σzy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−Cxz 21 ] Fxz 23 =Cxz 21
The σ zx term can be expressed as:
− Axz 0 +Axz 1*COS(Φ) +Bxz 1*SIN(Φ)− Axz 2*COS(2 Φ)− Bxz 2*SIN(2 Φ) Eq. (17)
where Axz 0 , Axz 1 , Axz 2 , Bxz 2 , and Bxz 2 are coefficients defined in Eq. (16).
The σ yz term can be expressed as:
Ayz 0 +Ayz 1*COS(Φ) +Byz 1*SIN(Φ) +Ayz 2*COS(2 Φ) +Byz 2*SIN(2 Φ), Eq. (18)
where Ayz 0 , Ayz 1 , Ayz 2 , Byz 2 , and Byz 2 are coefficients determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ); Ayz 0 =0.5*Cyz 01 *SIN(ψ) Ayz 1 =0.5*Cyz 12 *SIN(2 ψ) Ayz 2 =0.5*[Cyz 21 *SIN(ψ)+Cyz 23 *SIN(3 ψ)] Byz 1 =0.5*[Eyz 10 +Eyz 12 *COS(2 ψ)] Byz 2 =0.5*[Eyz 21 *COS(ψ)+Eyz 23 *COS(3 ψ)] Cyz 01 =σxz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0) Cyz 12 =−0.5*[σyz(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)+σzy(σh, σv, θ, Φ=90, σσm, hd, decc, ψ=0) −σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Cyz 21 =0.5*[σxz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0) −σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)+σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Cyz 23 =−Cyz 21 Eyz 10 =0.5*[σyz(σh, σv, θ, Φ=90, σm, hd, decc, σ=0)+σzy(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0) +σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)−σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Eyz 12 =0.5*[σyz(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)+σzy(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0) −σxz(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)+σzx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)] Fyz 21 =σyz(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−σzy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)−Cyz 21 Fyz 23 =Cyz 21
The σ zy term can be expressed as:
− Ayz 0 +Ayz 1*COS(Φ) +Byz 1*SIN(Φ)− Ayz 2*COS(2 Φ)− Byz 2*SIN(2 Φ), Eq. (19)
where Ayz 0 , Ayz 1 , Ayz 2 , Byz 2 , and Byz 2 are coefficients defined in Eq. (18).
The σ xy term can be expressed as:
Axy 0 +Bxy 1*SIN(Φ)+ Bxy 2*SIN(2 Φ), Eq. (20)
where Axy 0 , Bxy 1 and Bxy 2 are constants determined by the model parameters (σh, σv, θ, Φ, σm, hd, decc, ψ); Axy 0 =0.5*Dxy 02 *SIN(2 ψ) Bxy 1 =0.5*[σxy(σh, σv, θ, Φ=90, σσm, hd, decc, ψ=0)−σyx(σh, σv, θ, Φ=90, σm, hd, decc, ψ=0)] Bxy 2 =0.5*[σxy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)+σyx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)] Dxy 02 =[σxx(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0)+σyy(σh, σv, θ, Φ=0, σm, hd, decc, ψ=0) −σxy(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)+σyx(σh, σv, θ, Φ=45, σm, hd, decc, ψ=0)]
The σ yx term can be expressed as:
Axy 0 −Bxy 1*SIN(Φ)+ Bxy 2*SIN(2 Φ), Eq. (21)
where Axy 0 , Bxy 1 and Bxy 2 are constants determined in Eq. (20).
Equations (11) through (21) are used to compute the conductivity tensor at arbitrary formation azimuth Φ and tool eccentering azimuth ψ using only three pre-computed data points for which Φ=0, 45, and 90 degrees and ψ=0 for each of those three cases. The equations can be used to compute the conductivity tensor relatively quickly and at a low computational cost. With those choices for Φ and ψ, the disclosed azimuth expansion method allows us to reduce the borehole correction table size by a factor of 432, for example. Further reduction may be possible using fewer values but accuracy may suffer. The disclosed azimuthal expansion method makes the computation of the borehole correction table practical and may also improve the performance of the borehole correction inversion. Results of the above computations are shown in FIGS. 4-2 through 4 - 5 , and show good agreement. The expressions above for the tensor components are one example of a way to compute them using simplifying assumptions, but other expressions based on Equations 11 and 12 may be used and are within the scope of the present disclosure.
1.3 Multi-dimensional Interpolation
A multi-dimensional interpolation is used to determine the conductivity tensor for arbitrary values of the first 5 model parameters (hd, decc, σh, σv, θ) at the three Φ values (0, 45, and 90 degrees). The final conductivity tensor at arbitrary values of all the model parameters (hd, decc, σh, σv, θ, Φ, ψ) is determined using the azimuthal expansion. For best result, each of the dimensions in the multi-dimensional interpolation adopts an interpolation strategy best fit for the characteristics of that variable. For example, we use linear interpolation for the hd, decc, and θ variables. For ah variable, we use linear interpolation in logarithmic domain and convert the interpolated logarithmic value to linear. For σv variable, we convert the σv to σh/σv ratio, and use quadratic interpolation for the ratio variable, and convert the ratio to σv.
1.4 Test Results and Accuracy of the Forward Engine
FIGS. 12-1A through 12 - 1 I graphically illustrate an example comparison of the conductivity tensors from the forward engine versus the independently modeled conductivity tensors as a function of 1/Rh (σh). Similarly, FIGS. 12-2A through 12 - 2 I graphically illustrate a comparison of conductivity tensors from the forward engine versus the independently modeled conductivity tensors as the formation dip azimuthal angle varies from 0 to 360 degree in steps of 11.25 degrees. The hole diameter is 10.625 inches and the tool is eccentered by 3-inch in the direction ψ=30 degree from the borehole x-axis direction which is also the tool's x-direction.
The conductivity tensors generated by the forward engine are compared with independently modeled conductivity tensors and representative statistics of the percentage differences and absolute difference are graphically illustrated in FIGS. 12 - 3 A-D. The width of the histogram bar in FIGS. 12 - 3 A-D is 5%. The accuracy of the forward engine in this case is mostly within +/−2.5%.
The example of interpolation disclosed above for the forward engine is selected to match the characteristics of the tool responses. Those of ordinary skill in the relevant arts will recognize that other interpolation methods may be used.
2. Iterative Inversion
To invert for the formation parameters (σh, σv, θ, Φ) and also account for the tool position and borehole effects which are controlled by the borehole/tool parameters (decc and ψ), an iterative minimization algorithm may be used. In this example, two azimuthal angles Φ and ψ are computed from the measured conductivity tensor σm(i, j, k) using the technique described in section 1.1. The inversion now only needs to invert for four parameters (decc, σh, σv, θ) which minimizes a cost function for the case where hole diameter (hd) is given. If hd is not available, the inversion could invert for one more free parameter.
FIG. 13 shows a block diagram of an example of the inversion algorithm (and its interaction with other components shown in FIG. 3 ). An example of a cost function may be expressed as:
E = ∑ i , j , k w i , j , k ( σ m i , j , k - σ i , j , k ) 2 , Eq . ( 22 )
where the w i,j,k is weighting coefficient, σm i,j,k is the measured conductivity tensor and σ i,j,k is the modeled conductivity tensor. The index i, j, k, are for TR spacing, Tx orientation, and Rec orientation, respectively.
An example of the weighting function w i,j,k may be expressed in terms of standard deviation of the sonde error measurement, σstd i,j,k , as:
w
i
,
j
,
k
=
Max
(
0
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1
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std
i
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k
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Eq
.
(
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)
This expression of weighting function will make w i,j,k ≈1 if the amplitude ratio between sonde error standard deviation and the measurement is near 0. The weighting function will decrease as the amplitude ratio increases and w i,j,k ≈0 if the sonde error approaches the same magnitude as or larger than the measurement.
Other forms of the weighting function, such as w i,j,k =1, may also produce reasonable results. In this example, the larger amplitude measurements tend to have higher influence on the cost function.
Additional examples of cost function expressions are given below:
E
=
∑
i
,
j
,
k
w
i
,
j
,
k
abs
(
σ
m
i
,
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i
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Eq
.
(
24
)
E
=
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i
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w
i
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j
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(
σ
m
i
,
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-
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i
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j
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k
)
m
,
m
=
even
number
Eq
.
(
25
)
The minimum number of measurements that enter into the cost function should equal the number of unknown model parameters to be inverted. Usually, more measurements are available and could be used to enhance the statistics of the inversion process.
Starting from a set of initial guess model parameter values, a minimization algorithm can be used to determine the values of the inverted model parameters that produce the lowest possible cost function. For example a non-linear least square algorithm, such as Levenberg-Marquardt algorithm, may be used to search for the model parameter values that minimize the cost function in Eq. (22) through an iteration process. The exit criteria for the iteration may include the following:
(a) Number of iteration>Nmax;
(b) Cost function E i <ε1 (usually a very small constant); and
(c) ΔE<ε2 (usually a very small constant).
3. Initial Guess
A coarse grid search strategy is used to obtain the initial guess model parameters (decc, σh, σv, and θ). The coarse grid for the decc and Rh (or 1/σh) are constructed using σzz and σxz−σzx components of the measured conductivity tensors.
4. Estimation of Inversion Errors
The sensitivities of the measurements to the inverted parameters generally vary as functions of the inverted parameters. For example, the measurements are very sensitive to the change of Rv/Rh in low Rv/Rh ratio region and the sensitivity tapers off significantly when Rv/Rh>10. The sensitivity to Rh, Rv, and dip generally drops off quickly as Rh becomes large (e.g., Rh>50 ohm-m). The higher the sensitivity of a given parameter in the solution region is, the higher the likelihood that accurate inversion results will be obtained.
The sonde error statistics (σstd), which represent the uncertainty of the measurements, and the sensitivity function may be used to estimate the errors of the inverted parameters. In this example, these error estimates will be used for quality control purposes to help interpret the inverted answers.
The sensitivity function Spn(i, j, k) for a given measurement σ(i, j, k) to a given parameter p n may be defined as follows:
Spn ( i , j , k ) = ∂ σ ( i , j , k ) ∂ p n Eq . ( 26 )
where index i represents TR spacing, index j represents transmitter orientation and index k for receiver orientation, pn represents any inverted parameter. For this case, n=1, 2, 3, 4, etc. corresponds to parameters decc, σh, σv, and θ, respectively.
In this example, for practical implementation, the difference in σ(i, j, k) due to a 2% variation of the p n parameter is computed, instead of the partial derivative in Eq. (26).
The error of the inverted pn parameter, Δpn, may be expressed as a weighted average over all the selected measurements for the inversion.
Δ pn = ∑ i , j , k wa ( i , j , k ) * σ std ( i , j , k ) / Spn ( i , j , k ) Eq . ( 27 )
Here, wa(i, j, k) is the weighting coefficient for the contribution due to σ(i, j, k) measurement.
Various strategies can be used to set the wa coefficient, e.g., an amplitude weighting strategy. The wa coefficient may be expressed as:
wa ( i , j , k ) = σ ( i , j , k ) ∑ i , j , k σ ( i , j , k ) Eq . ( 28 )
5. Borehole Effects and Borehole Correction
In this example, the processing after the inversion stage produces a set of model parameters (decc, σh, σv, θ, Φ, ψ) using a selected subset of measured conductivity tensor σm(i, j, k) through an inversion algorithm for every input data frame. These inverted model parameters can be stored as function of depth similar to conventional logs.
Each of the measured conductivity tensor σm(i, j, k) has a measurement depth that is usually the mid-point between the transmitter and the receiver. Different transmitter-receiver (“TR”) spacing conductivity tensor measurements have different measurement depth.
In this example, at any given depth, the inverted parameters together with the hole diameter (hd) log will be used to compute the responses of the tool with and without the borehole. The response with the borehole, σbh(i, j, k), will be computed using the forward engine disclosed above. The response without the borehole, σnbh(i, j, k), may be computed through an analytic formula known in the art. The borehole effect for the measurement at that measured depth, Δσ(i, j, k), may be expressed as:
Δσ( i, j, k )=σ bh ( i, j, k )−σ nbh ( i, j, k ) Eq. (29)
The borehole corrected measurements at that measured depth, σbhc(i, j, k), may be expressed as:
σ bhc ( i, j, k )=σ m ( i, j, k )−Δσ( i, j, k ) Eq. (30)
The borehole corrected conductivity tensor may be used in subsequent processing to estimate, for example, borehole corrected formation properties such as borehole corrected porosity and borehole corrected fluid saturation.
6. Example of Borehole Correction Processing Using Model Data
FIGS. 14-1 and 14 - 2 are example comparisons of theoretical model data for which the correct answers are known to demonstrate the accuracy and robustness of the borehole correction processing. In this example, a set of 1000 test cases that covers a wide range of borehole diameter, eccentering distance, Rh, Rv, and dip angles are modeled. The borehole and formation parameters for these test cases are selected such that they are at the off-grid position referenced to the grid points used in the borehole model database.
FIG. 14-1 is an example of borehole correction processing results using noiseless off-grid theoretical model data. The borehole correction algorithm outputs are compared with the known model parameter answers. FIG. 14-1A is for Rh and Rv; FIG. 14-1B is for dip angle and decc; and FIG. 14-1C is for formation azimuth (AZF) and tool eccentering azimuth (AZT). The Rh shows a substantial match to the predicted answer. The Rv is also very robust. A small error of Rv is seen in the high resistivity region. This is consistent with the disclosed prediction that in high resistivity, the measurement is not sensitive to Rv/Rh ratio. Any small amount of error in interpolation and inversion process may cause some error in Rv in high resistivity region. The inverted dip angle matches very well with the predicted answer. Again, a small error can be seen in the high resistivity region for the same lack-of-sensitivity reason. The inverted decc also matches the predicted answer very well. The model parameters for the formation azimuth angle and tool eccentering azimuth angle are both zero degrees. To avoid angle wrapping near zero degree, both azimuthal angle answers are shifted by 90 degrees and a modulus of 360 of the shifted results is performed. The results of the disclosed formula for computing these two azimuthal angles match the predicted answer to within a fraction of a degree.
The effect of random noise on the borehole correction algorithm is also evaluated using these off-grid model data. The standard deviation sonde error measurement, σstd(i, j, k), is added or subtracted in a random fashion to the input data, σm(i, j, k), to simulate random noise. The processing results from this noisy model data are shown in FIG. 14-2 in the same format as that for the noiseless case in FIG. 14-1 . The borehole correction algorithm is very robust in handling the random noise. The noise did not cause any appreciable effect on the inverted Rh. For Rv, Dip, and decc, the inverted results substantially match the noiseless case, except with a slightly larger error in the high resistivity region where the sensitivity to the parameters is low. The formation azimuth angle and tool eccentering azimuth angle both show slightly elevated error at high resistivity region where the signal-to-noise ratio is low.
In addition to accuracy and robustness, the nominal processing speed for the disclosed system and method is fast enough to serve as a real-time answer product at the wellsite. The disclosed system and method are applicable for downhole tools, wireline and LWD conditions, for example, and may be implemented as real-time well site answer product as well as computer center product.
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 scope of the invention as defined by the appended claims which follow.
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A method for correcting formation properties due to effects of a borehole is disclosed. The method includes obtaining voltage measurements using a logging tool disposed in a borehole penetrating a subsurface formation. The method further includes using a processor to: determine a tensor for the formation using the voltage measurement. For a given set of parameters, the processor determines, based upon the voltage measurements, a parameter value for each parameter in a subset of the set of parameters. The method further uses the processor to compute a borehole-inclusive modeled tensor that includes the effects of the borehole using the parameter values, optimize the parameter values using the determined tensor and the borehole-inclusive tensor, compute an optimized tensor using the optimized parameter values, compute a borehole corrected tensor using the optimized tensor, and determine at least one borehole corrected formation property using at least one of the borehole corrected tensor or the optimized parameter values.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to hierarchical data communication systems and more particularly relates to a branch-based validation method for redundant devices.
[0003] 2. Description of the Related Art
[0004] Data communication systems, such as computer networks, often include complex arrangements of a multitude of digital data devices. For example, as illustrated by the schematic block diagram of FIG. 1 , a traditional data communication system 10 may include digital data devices comprising a server computer (“server”) 12 connected to a user computer (“host”) 14 having digital data storage media 16 via a communication network 18 such as a local area network (“LAN”), a wide area network (“WAN”), a wireless network, or similar communication path. These exemplary digital data devices manipulate, process, transmit, and store digital information and generally include data storage registers 20 or similar memory devices for holding and displaying status information 22 pertaining to functionality and operability. A user of this traditional data communication system 10 or a system management application 24 may query the status information 22 of a digital data device to determine if it is currently powered on and operational or whether it is powered down, in standby mode, disabled, inaccessible, or otherwise not operational.
[0005] The traditional data communication system 10 may also include auxiliary devices such as a power controller card 26 , a power supply 28 , a fan 30 for cooling the power supply 28 , and a battery 32 for providing auxiliary power. While the primary purpose of these auxiliary devices may not include manipulation, processing, transmitting, or storing digital information, these auxiliary devices may also include data storage registers 20 including status information 22 . As with digital data devices, a user or system management application 24 may query the status information 22 of an auxiliary device to determine if it is currently powered on and operational or whether it is powered down, in standby mode, disabled, inaccessible, or otherwise not operational. Interconnections involving auxiliary devices may include power-transmission wires 34 and data communication channels 36 which may be either wired or wireless.
[0006] Complex data communication systems 100 , as illustrated by the schematic block diagram of FIG. 2 , are traditionally arranged in a heirarchical structure with each component in communication with one or more other components. Here, a server 112 having a data storage register 120 including status information 122 may be in communication with multiple power controller cards 126 that are, in turn, in communication with multiple power supplies 128 . The power supplies 128 may be in communication with multiple batteries 132 . By including multiple system components of like kind, a complex data communication system 100 may continue to function even if one or more system components fail or become inoperable. A user or a system management application 124 may query the status information 122 of individual components via the communication networks 118 .
[0007] In order to prevent a single-point failure, as may occur in the traditional data communication system 10 of FIG. 1 , complex data communication systems 100 generally include redundant component devices. For example, in order to prevent the disablement of a first power controller card 126 a from causing a catastrophic system failure, a second power controller card 126 b redundantly connects the power supplies 128 a ,- 128 d to the server 112 . Likewise, the utilization of redundant power supplies 128 a ,- 128 d prevents the failure of either one from interrupting power flow from the batteries 132 a ,- 132 h to the power controller cards 126 a , 126 b.
[0008] The status information 122 stored in each data storage register 120 indicates the current viable of its associated device. For example, two mutually exclusive status conditions may be obtained, indicating either a currently nominal situation or an error within in the network. Another error condition known as a “can't happen” condition may also be obtained. However, unless an error condition is passed up the hierarchical structure, it may be difficult for the system management application to evaluate exactly which device is currently not operating properly.
[0009] As with all redundant devices, the status or information gathered from the devices needs to be verified and validated, particularly against its redundant partners. For example, if there are 3 peripherals in the system that are effectively redundant, their status must be compared against each other to confirm commonality and protect against conflicting status.
[0010] As the amount of layers of devices increase, and as the number of redundant devices per layer increase, there is an exponential increase in the number of different devices and paths that need to be verified.
[0011] A variety of diagnostic methods are known in the art involving various testing procedures to determine which component of the network is not functional. Commonly, however, the diagnostic methods require an operator to take at least part of the computer system offline in order to run the appropriate testing procedures.
[0012] Thus, a need exists for a system for analyzing generated mutually exclusive conflicts in a hierarchical network of redundant devices that ensures the network remains online, operable and usable. In addition, a need exists for a method of analysis and resolution of the mutually exclusive conflicts in a computer system, again under online conditions.
[0013] From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that perform a step-by-step approach to failure analysis in the online state by traversing the network of devices. Beneficially, such an apparatus, system, and method would perform this validation process in an organized, expandable, and portable fashion.
SUMMARY OF THE INVENTION
[0014] The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available redundant peripheral systems. Accordingly, the present invention has been developed to provide an apparatus, system, and method for validating information in a hierarchical structure that overcome many or all of the above-discussed shortcomings in the art.
[0015] The apparatus to validate information in a hierarchical structure is provided with a plurality of modules configured to functionally execute the necessary steps of validating status information. These modules in the described embodiments include a validation module comprising a comparison module and an exclusion module.
[0016] The apparatus, in one embodiment, is configured to validate a first plurality of status information residing within a first plurality of redundant devices. The apparatus is further configured, in one embodiment, to identify an error condition if the first plurality of status information is inconsistent. In a further embodiment, the apparatus may be configured to disregard all but one of the first plurality of redundant devices if the first plurality of status information is consistent.
[0017] A system of the present invention is also presented to validate information residing within a hierarchical structure of redundant devices. The system may be embodied as a hierarchical structure of redundant devices and a server in communication with the hierarchical structure of redundant devices. In particular, the system, in one embodiment, includes a validation module for verifying a first plurality of status information of a first plurality of redundant devices.
[0018] The system may further include a comparison module for comparing the first plurality of status information, an identification module for identifying an error condition of the first plurality of devices if the first plurality of status information is inconsistent, and an exclusion module for disregarding all but one of the first plurality of devices if the first plurality of status information is consistent.
[0019] A method of the present invention is also presented for validating information in a hierarchical structure of redundant devices. The method in the disclosed embodiments substantially includes the steps necessary to carry out the functions presented above with respect to the operation of the described apparatus and system. In one embodiment, the method includes comparing a first plurality of status information residing within a first plurality of redundant devices, identifying an error condition of the first plurality of redundant devices if the first plurality of status information is inconsistent, and disregarding all but one of the first plurality of redundant devices if the first plurality of status information is consistent.
[0020] In a further embodiment, the method includes comparing a second plurality of status information residing within a second plurality of redundant devices in communication with the one of the first plurality of redundant devices, identifying a second error condition of the second plurality of redundant devices if the second plurality of status information is inconsistent, and disregarding all but one of the second plurality of redundant devices if the second plurality of status information is consistent.
[0021] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
[0022] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
[0023] These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
[0025] FIG. 1 is a schematic block diagram illustrating a traditional data communication system.
[0026] FIG. 2 is a schematic block diagram illustrating a complex data communication system.
[0027] FIG. 3 is a schematic block diagram illustrating one embodiment of an information validation system in accordance with the present invention; and
[0028] FIG. 4 is a schematic flow chart diagram illustrating one embodiment of an information validation method in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.
[0030] Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.
[0031] Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form in, and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.
[0032] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0033] The invention disclosed herein may be implemented as a method, apparatus, or signal bearing medium using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. A signal bearing medium may take any form capable of generating a signal, causing a signal to be generated, or causing execution of a program of machine-readable instructions on a digital processing apparatus. A signal bearing medium may be embodied by a transmission line, a compact disk, a digital-video disk, a magnetic tape, a Bernoulli drive, a magnetic disk, a punch card, a flash memory, an integrated circuit, an optical storage device, a floppy disk, an electrically-erasable programmable read-only memory (“EEPROM”), a volatile memory device, a non-volatile memory device, a field programmable gate array (“FPGA”), an application-specific integrated circuit (“ASIC”), a complex programmable logic device (“CPLD”), a programmable logic array (“PLA”), a microprocessor (“uP”), a programmable logic device (“PLD”), or other digital processing device.
[0034] Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
[0035] FIG. 3 depicts one embodiment of an information validation system 200 in accordance with the present invention, including a validation module 202 which, in turn, includes a comparison module 204 , an exclusion module 206 , and an identification module, as well as a server 212 and a pair of first level peripheral devices 214 a , 214 b . Each of the first level peripheral devices 214 a , 214 b are redundant similar devices that report to the server 212 over first level communication networks 213 a , 213 b . Second level peripheral devices 216 a , 216 b are also redundant peripheral devices that report to the first level peripheral devices 214 a , 214 b over second level communication networks 215 a , 215 b . The information reported by the second level peripheral devices 216 a , 216 b to the first level peripheral devices 214 a , 214 b is included in the information reported by the first level peripheral devices 214 a , 214 b to the server 212 .
[0036] The third level of peripheral devices 218 a , 218 b are yet additional redundant devices that that report to the second level peripheral devices 216 a , 216 b over third level communication networks 217 a , 217 b . The information reported by the third level peripheral devices 218 a , 218 b to the second level peripheral devices 216 a , 216 b is included in the information reported by the second level peripheral devices 216 a , 216 b to the first level peripheral devices 214 a , 214 b which is, in turn, reported to the server 212 .
[0037] Because the server 212 does not directly interface with the second level peripheral devices 216 a , 216 b and the third level peripheral devices 218 a , 218 b , the server 212 must access status information 222 stored in data storage registers 220 through any intermediary devices, such as the first level peripheral devices 214 a , 214 b . As each level of peripheral devices is added to the information validation system, an exponential increase in the number of required validation paths occurs.
[0038] However, rather than applying a massive comparison of all elements against their redundant devices, the present embodiment of the invention breaks up the validation code into a series of simple checks using a folding algorithm. Additionally, the present invention utilizes the redundant nature of the peripheral devices to allow layers of peripheral devices to be inserted or removed without overhauling the design. The functional operation of the information validation system is best illustrated by the schematic flow chart diagram of the information validation algorithm 300 of FIG. 4 .
[0039] The schematic flow chart diagram that follows is set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
[0040] First, the status information 222 of the first level peripheral devices 214 a , 214 b is compared 302 by the comparison module 204 . If the status information 222 of the first level peripheral devices 214 a , 214 b is inconsistent 304 , the inconsistency is reported or managed 306 by the comparison module 204 . If the status information 222 is not inconsistent 304 , then one of the first level peripheral devices 214 b is excluded 308 from the validation process. In other words, if the status information of each first level peripheral device 214 a , 214 b is mutually compatible, extrinsic redundant first level peripheral device 214 b , including any subordinate peripheral devices, may be removed from the set of peripheral devices to be analyzed by the exclusion module 206 . If no more levels of peripheral devices exist 310 , the algorithm terminates 312 . However, if at least one additional level of peripheral devices does exist 310 , then the algorithm returns to the step of comparing status information between redundant devices 302 .
[0041] In one exemplary embodiment of the invention, the status information 222 of the second level peripheral devices 216 a , 216 b of the remaining first level peripheral device 214 a is compared 302 by the comparison module 204 . If the status information 222 of the second level peripheral devices 216 a , 216 b is consistent, one of the second level peripheral devices 216 b , including any subordinate peripheral devices, is excluded 308 from the validation process by the exclusion module 206 .
[0042] Traversing down the hierarchical structure of the information validation system, the status information 222 of the third level peripheral devices 218 a , 218 b , 218 c of the remaining second level peripheral device 216 a is compared 302 by the comparison module. If the status information 222 of the third level peripheral devices 218 a , 218 b , 218 c is consistent, all but one of the third level peripheral devices, including any subordinate peripheral devices, is excluded 308 from the validation process by the exclusion module 206 .
[0043] If the information validation algorithm terminates 312 without detecting inconsistent status information among redundant peripheral devices, then the status information of all of the peripheral devices in the information validation system 200 is deemed to be validated. If, however, an inconsistency exists among the status information 222 of like peripheral devices residing on the same level of the information validation system 200 , the level of the non-validated peripheral devices is noted 306 by the identification module 208 before the information validation algorithm terminates 312 .
[0044] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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An apparatus, system, and method are disclosed for validating information in a hierarchical structure of redundant devices. A first plurality of redundant devices is examined to determine if status information residing within each of the redundant devices is consistent with each other. If the status information is inconsistent, the first plurality of redundant devices is identified as containing an error condition. If, however, the status information of the first plurality of redundant devices is consistent, all but one of the first plurality of redundant devices is excluded from further consideration. A second plurality of redundant devices, in communication with the all but one of the first plurality of redundant devices, is then examined to determine if status information residing within each of the second level of redundant devices is consistent with each other.
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BACKGROUND OF THE INVENTION
A popular type of lamp, used on desks, work tables, drawing boards, for medical examinations and the like, utilizes a bracket having a principal arm mounted on a fulcrum, and an extensible forward arm hinged to the principal arm. One form of extensible lamp bracket is both counter-balanced and tiltable out of a central vertical plane; this form is disclosed in U.S. Pat. No. 3,391,890. The mechanism there shown contains provisions which permit three degrees of angular movement about the balance point, as with a ball joint. These provisions occupied the balance point itself so that electrical connectors could not be internal, and the fulcrum hinge presented a similar wiring problem.
In this type of lamp bracket, balancing at various degrees of extension was achieved by maintaining maintained proportionality between the extension of the forward arm forwardly of the balance point, and aft movement of the counter-balance. Proportionality was achieved by a rod which in effect maintains the forward arm parallel to a link from the balance point to the fulcrum hinge of the principal arm. In the patented construction, the fulcrum hinge was spaced below the principal arm; the parallelism-maintaining rod was spaced still further below. This separation interfered with compact folding of the bracket.
SUMMARY OF THE INVENTION
The principal purpose of the present invention is to create joint and link members, in a counter-balanced extensible bracket of the type described, which permit the drawing of concealed electrical connectors through the point about which there are three degrees of freedom of angular movement, and also through the fulcrum hinge. Another purpose is to provide improved compactness of folding of such an extensible bracket, so that its parallelism maintaining rod and forward arm may fold back against the principal arm with the three being closely adjacent to each other. Still other purposes will be apparent from the detailed disclosure which follows.
Generally summarizing the present invention, I provide three degrees of angular movement at the balance point, without interfering with electrical connectors drawn therethrough. The mechanism which provides each degree of freedom is located offset from the balance point itself, which the mechanism encompasses. Wiring is carried up through a lower support which rises from the swivel mechanism. In the embodiment illustrated the wiring extends from this swiveling support through a hollow trunnion whose supporting joints are laterally offset from the balance point. At the trunnion midpoint is the end of a hollow stub shaft formed about a center plane axis perpendicular to the lateral trunnion axis. Loosely clamped about this stub shaft, so that it may turn thereon, is the swivel socket portion of a hollow link which extends from the balance point to the fulcrum hinge, on which the principal bracket arm is mounted. In this hollow mechanism the wiring is concealed.
The fulcrum hinge axis is located along the center line of the principal arm instead of below it as in the patented construction above referred to. The principal arm is there divided into two portions offset from the central vertical plane of the bracket. The slot between these offset arm portions accommodates the upper end of the link. When the supplemental arm is folded back on the principal arm, nearly the entire link passes into the slot; there remains projecting only a link end portion which extends to the balance point and a lug on which the parallelism-maintaining rod is mounted. This permits exceptional compactness of folding.
It is to be understood that this preliminary summary is furnished to aid in understanding the disclosure which follows and does not limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is an elevational view, partly broken away, of a counter-balanced extensible lamp bracket embodying the present invention, shown with the tiltable bracket partially extended in the vertical plane. The phantom lines show the bracket portions fully folded vertically.
FIG. 2 is a plan view corresponding to FIG. 1.
FIG. 3 is an enlarged true view, broken away, showing the fulcrum hinge and counter-balance portion of FIG. 1, as seen from the upper left.
FIG. 4 is a side view, partly broken away, of the parts shown in FIG. 3, in their same relative positions.
FIG. 5 is a true view of the joint members seen from the left and below of FIG. 4. The phantom lines show the link member thereof swiveled 90°, as when the bracket is tilted out of the central vertical plane.
The heavy dash lines in the enlarged fragmentary views FIGS. 3, 4, and 5 indicate the path of wiring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The terms applied to the relative position of the parts, throughout this description and the appended claims, define their positions when the base 10 is on a horizontal level surface and the other parts are in their relative positions shown in FIG. 1.
Certain parts of the present invention are similar to parts having corresponding functions disclosed in said prior U.S. Pat. No. 3,391,890; these corresponding parts will be first described. A relatively small lightweight circular base 10 is utilized having a central vertical base swivel bushing 11 which defines a vertical support axes a. The base 10 may be equipped with a pair of common support recesses 12 which are narrowed at one side so as to grasp projecting heads of nails or screws, thus to permit wall mounting of the base 10.
Other parts of the present bracket, which will be familiar from said prior patent, are: the swivel mounted lamp head 14, its mounting joint 15, which moves angularly relative to a supplementary hollow arm 16, the hinge joint 17 of the supplementary arm 16 to the principal arm 18, which joint also includes a lug fitting 19 for mounting the upper end of a parallelism-maintaining rod 20, and the mass counter-balance 22 supported at the aft end of a slotted fulcrum hinge fitting, to be described, mounted on that end of the principal arm 18 opposite to the hinge joint 17.
A support point b, about which the present bracket provides limited movement about three axes, is seen in FIGS. 1, 4, and 5. It lies at the intersection of the axis a provided by the base swivel bushing 11, a lateral axis c perpendicular thereto, as seen in FIG. 5, and a central plane axis d perpendicular to the lateral axis c and rotatable relative thereto through a substantial angle as partly seen in FIG. 1. The support point b is thus spaced vertically from the base swivel bushing 11, and as will be seen is likewise spaced from the members which provide for support and rotation relative to the other axes c, d.
Arising from the base 10 and supported in the swivel bushing 11 by a pin 23 are the somewhat pear-shaped lower fitting ends 24 of a hollow tubular support 25 which rises curving forward from the axis a and then returns toward it as seen in FIG. 1. At its upper end, best seen in FIGS. 4 and 5, is a non-rotatable hollow fitting 27 split along the central vertical plane of the bracket, and having on each side thereof an inward facing hollow trunnion lug 28. The fitting 27 may be held together by a simple clamping screw (not shown) whose tightening exerts a variable clamping force on the trunnion lugs 28. The trunnion lugs 28 define the lateral axis c through the support point b; and as seen in FIG. 5, they are spaced to both sides of it, so that electrical connectors, generally designated e, drawn through the fitting ends 24 into the tubular support 25 and then to the hollow fitting 27, may pass through one of its hollow trunnion lugs 28 and through the support point b itself.
Mounted between the trunnion lugs 28 is a first link part generally designated 30, which supports a swiveling second link part generally designated 31. Together they extend from the support point b to the fulcrum hinge point f as seen in FIGS. 1 and 4. The first link part 30 includes a hollow tubular trunnion 34, best seen in FIG. 5, which extends between and whose ends are embraced by the trunnion lugs 28 of the fitting 27. A short hollow stub shaft 36 extends perpendicular to the trunnion 34. The axis of the stub shaft 35 is the center plane axis d.
The stub shaft 35 of the first link part 30 is provided with an enlarged preferably cylindrical flange 37 which is grasped by the second link part 31, hereafter to be described, for permitting relative rotation about the center plane axis d. Movement about this axis will tilt all portions supported by the second link member 31--including the lamp head 14, the principal and supplementary arms 18, 16, the parallelism-maintaining rod 20 and the counter-balance 22--out of the center plane illustrated in FIGS. 1 and 2.
The second link part 31 consists of symmetrical left and right hand pieces 38, 39 which, when the link part 31 is in position shown in FIG. 1, mate at the central vertical plane of the lamp bracket. The pieces 38 and 39 are hollowed to provide a path for the wiring as seen by the heavy dash lines of FIGS. 3, 4, and 5. Together the parts 38, 39 present a cylindrical hollowed neck 41 entering into a cylindrical swivel socket 42 in which the stub shaft 35 and its cylindrical flange 37 of the first link part 30 are received. Hence the second link part 31 swivels on the axis d, as shown in FIG. 5. Although its entrant neck and swivel socket 42 are on a common axis, the part 31 curves substantially in an arc; within the arc are flat tab portions 43 which meet at the center plane and are bored to accommodate a lateral pin 44 which mounts one end of the parallelism-maintaining rod 20. A screw (not shown) through the tab portions 43 holds the link pieces 38, 39 together so their socket 42 exerts adjustable clamping pressure on the flange 37 of the first link part 30.
A hollow passage 46 extends through the second link part 31 from the swivel socket 42 curvedly to its fulcrum hinge end 48, best seen in FIGS. 3 and 5. In the embodiment shown, the fulcrum hinge end 48 has symmetrical hollow clevis portions 49 offset to both sides of the center plane. On their outer sides (that is, those farther from the center plane) the clevis portions 49 have annular fulcrum support projections 51 whose hollows are aligned with each other to define the axis of the fulcrum hinge f. On this same axis, the inner sides of the clevis portions 49 have bores 52 which lead inwardly. These bores connect with a lateral bore 53 through the aft end of the stem portion 54 of a substantially T-shaped center plane support 55. The stem portion 54 is likewise hollow, so that as seen in FIG. 3 a wire through the hollow passage 46 may pass through one of the clevis portions 49 and its bore 52, and then to the center plane through the clevis lateral bore 53, and then forward through the stem portion 54. Optional annular interfit provisions may be molded to provide support between the clevis portions 49 and the center plane member 55; however in the embodiment shown the outward projecting fulcrum supports 51 are adequate for support at the fulcrum hinge f.
One unique feature of the present invention is that the fulcrum hinge f extends through the axis of the principal arm 18, on which axis the counter-balance 22 is also located. This location of the fulcrum hinge f is accomplished by offsetting the fulcrumed portion of a principal arm fitting 60 from the vertical center plane, providing a slot 68 in it, so the second link part 31 may move freely in this plane. This accommodation is of particular importance when the lamp bracket is fully folded, as seen in the phantom lines in FIG. 1.
FIG. 3 best illustrates the slotted fulcrum fitting generally designated 60, preferably made up of upper and lower molded plastic halves 61, 62 held together by forward screws 63, which clamp between them the end of the tubular principal arm 18, and aft screws 64 which mount the strap 65 around the counterweight 22. Also clamped in place by the screws 63 is the T-shaped center plane member 55. Parallel longitudinal portions 66 of the fitting halves 61, 62 are offset from the center plane sufficiently to accommodate the second link part 31, providing between them a slot 68, whose length is sufficient to accommodate the link part 31 in the fully folded position shown in phantom lines in FIG. 1. At their mating mid-plane, at which the lateral fulcrum axis f is located, the upper and lower halves 61, 62 have molded semi-cylindrical bushing portions 69 which receive the projecting fulcrum supports 51 of the clevis ends 49 of the link parts 31.
The hollow fulcrum supports 51 enter into the hollows of the longitudinal fitting portions 66, as seen in FIG. 3, and are of adequate size to conduct wiring. Thus in a simple embodiment, the T-shaped center plane member 55 may be omitted, and the wiring to an incandescent lamp carried outward through one of the fulcrum support projections 51 and the mating bushing parts 69 into the fitting halves 61, 62 and thence forward through the principal arm 18.
Instead of utilizing a simple incandescent bulb, it may be desirable to use a transformer to change the voltage, as is common with high intensity lamps; or if a fluorescent lamp is to be utilized, ballasts or chokes may be required. With such a design, the transformer, ballast or choke may be incorporated as part of the counter-balance 22. In such case the hollows in the fulcrum fitting 60 may conduct wiring aft to such a component and thence forwardly to the principal arm 18.
As taught in said prior Pat. No. 3,391,890, the range of angular movement of the central plane axis d about the lateral axis c should be restricted so that this central plane axis d does not come into coincidence with the vertical support axis a. It is inherent in this balanced bracket construction that a line connecting the support point b with the fulcrum f must be substantially parallel to the line from the hinge joint 17 to the center of gravity of the masses forward of the support point b, that is, substantially parallel to the supplementary arm 16. Since in its desired range of movement this arm 16 may be vertical, the second link part 31 cannot be straight but must be curved aft and up, as shown in FIG. 1. This requirement of curvature is utilized to achieve better folding. The slot 68 conveniently accommodates nearly the entire curved second fitting member 31, leaving exposed only the knuckle-like joint at the support point b. The result is exceptional compactness of folding, illustrated in phantom lines of FIG. 1, in which the principal arm 18, parallelism-maintaining rod 20 and supplementary arm 16 are brought close together and parallel to each other.
Inasmuch as the concept of three degrees of freedom of angular movement about a point is associated with ball joints, it was not originally anticipated that wiring could be brought through the support point itself, to accommodate any such angular movement merely by flexure. Similarly, it was not apparent how to carry wiring, in a counter-balanced bracket, subject only to flexure, through this fulcrum joint of a levered arm which entered both forward and aft of the joint. Nor was it apparent to create an offset levered arm with a slot in which to accommodate a curved link of a parallel-maintaining mechanism.
A unique advantage of the type of counter-balanced bracket described in this specification is: since balance is achieved about the balance point with three degrees of freedom of angular position and throughout the range of extension of the bracket, the support axis from the base to the balance point, which axis is hereinabove described as "vertical" may be inclined at any angle or even positioned horizontally. Thus a drafting board on which the bracket may be mounted can be readily inclined without affecting the function of the bracket; or the base plate may be mounted on a vertical wall, to position this "vertical" axis horizontally. The very flexibility of the present bracket in use at varying positions and angles of inclination, makes it difficult to select words to describe the individual parts and their functions. In drafting this specification, the words used were selected to describe the members as they appear in the elevational view, FIG. 1, with the support axis to the balance point vertical and the central plane of the folding bracket vertical. The breadth of this disclosure is not to be impaired by the selection of this view as a basis relative to which the descriptive terms were chosen. Likewise the wording of the claims, insofar as position and spatial relationships are described, applicable directly to said elevational view FIG. 1, is to be understood to apply to the members and parts of the apparatus at every position and at every angle which they may assume; and this breadth of interpretation is to be applied also to corresponding members of equivalent apparatus.
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In that type of extensible, tiltable counter-balanced lamp bracket in which three degrees of freedom are provided about a balance point, the mechanism which furnishes the 3° of freedom also provides a hollow encompassing the balance point, so that connectors may be drawn directly therethrough. A hollow link extends from the balance point to a fulcrum hinge at which it mounts the principal counter-balanced arm. The arm there is directed into two portions offset from the center plane. The offsets of the principal arm provide a slot in which the link means is accommodated when the extensible bracket is folded.
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FIELD OF THE INVENTION
[0001] The present invention relates to a low-pass filter for a wireless communication system; and, more particularly, to a HTS low-pass filter for suppressing broadband harmonics.
DESCRIPTION OF THE PRIOR ART
[0002] Recently, as various wireless communication systems and services are developed intensively, the considerable performance improvement such as small insertion loss, high selectivity, high sensitivity and small size are needed in development of communication components for a cellular phone and a personal communication system. In order to satisfy these demands, the development of materials, design (circuits) and fabrication (processes) technologies are essential for the communication devices.
[0003] Since low-pass filter (LPF) is a frequency selective and passive device with low levels of attenuation, LPF is widely used to reject harmonics or spurious signals in a integrated mixer, a voltage controlled oscillator (VCO) and so on. But an open-stub type low-pass filter and a step-impedance type low pass filter have a narrow stopband (about 3 times of cutoff frequency in case of a conventional LPF).
[0004] [0004]FIGS. 1A and 1B show an equivalent circuit diagram and a schematic diagram of a conventional microstrip low-pass filter.
[0005] [0005]FIG. 1A shows the equivalent circuit diagram of the lumped-element low-pass filter designed through the transformation of impedance level and frequency scale from the prototype low-pass filter (not shown). The lumped-element low-pass filter (or π-type low-pass filter) includes an inductance L 2 corresponded to the microstrip transmission line, a first shunt capacitance C 1 and a second shunt capacitance C 2 corresponded to the two parallel microstrip open-stubs (in this case: C 1 =C 2 ).
[0006] Referring to FIG. 1B, the conventional microstrip low-pass filter includes a crystalline substrate 180 (hereinafter, referred to as “an MgO substrate”), a signal transmission input port 150 and a signal transmission output port 160 , two parallel stripe lines 170 of a microstrip open-stub type, a microstrip line 140 and a ground plane 190 .
[0007] The signal transmission input port 150 and the signal transmission output port 160 are fabricated on both edges of the top face of the MgO substrate 180 . Two parallel microstrip open-stubs 170 between the signal transmission input port 150 and the signal transmission output port 160 are perpendicular to a signal propagation direction. Therefore, the microstrip line 140 is perpendicular to two parallel microstrip open-subs 170 . The groundplane (e.g., Au or Ag film) 190 is coated at the bottom (backside) of the MgO substrate 180 .
[0008] In general, there are some problems in the conventional low-pass filter as described above. Since the conventional low-pass filter has a narrow stopband range in frequency domain, an interference occurred by the adjacent wireless communication systems and a noise generated by the communication system itself are quite serious.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of the present invention to provide a low-pass filter having a high-efficiency broad stopband characteristics, in which attenuation poles and a frequency range of the stopband can be controlled easily.
[0010] In accordance with an aspect of the present invention, there is provided a low-pass filter comprising: a circuit pattern having at least one or more units, wherein the circuit pattern includes a coupled line section having a pair of parallel stripe lines and a transmission line section having a pair of parallel straight lines whose two ports of one side are opened and whose two ports of the other side are connected to each other, each port of one side of the pair of the parallel straight lines being connected with each port of one side of the coupled line section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, in which:
[0012] [0012]FIGS. 1A and 1B show an equivalent circuit diagram and a schematic diagram of a conventional microstrip low-pass filter, respectively;
[0013] [0013]FIGS. 2A to 2 C illustrate a schematic diagram, a basic circuit diagram and an equivalent circuit diagram of a high-temperature superconductor (HTS) coupled line low-pass filter in accordance with the present invention, respectively;
[0014] [0014]FIGS. 3A to 3 C illustrate a schematic diagram, a basic circuit diagram and an equivalent circuit diagram of a seventh-order coupled line low-pass filter in accordance with the present invention, respectively;
[0015] [0015]FIGS. 4A and 4B are graphs illustrating simulated results of the seventh-order coupled line low-pass filter shown in FIG. 3A;
[0016] [0016]FIGS. 5A to 5 F are cross-sectional views illustrating sequential steps associated with a method for fabricating the seventh-order coupled line low-pass filter; and
[0017] [0017]FIG. 6 shows comparison of the simulated and measured results of the seventh-order HTS coupled line low-pass filter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] [0018]FIG. 2A shows a microstrip circuit of a high-temperature superconductor (HTS) low-pass filter (LPF) in accordance with an embodiment of the present invention. Referring to FIG. 2A, the HTS low-pass filter includes a transmission line section 241 and a coupled line section 242 . The transmission line section 241 includes a microstripe line 243 and the coupled line section 242 includes a pair of parallel stripe lines 244 and 245 .
[0019] The pair of the parallel stripe lines 244 and 245 are stacked on a HTS epitaxial thin film (not shown). A first lead line 246 is extended from the first parallel stripe line 244 to a signal transmission input port. A second lead line 247 is extended from the second parallel stripe line 245 to a signal transmission output port. The microstripe line 243 connects the first and the second parallel stripe lines 244 and 245 . The microstripe line 243 is more slender and longer than the first and the second lead lines 246 and 247 .
[0020] At this time, an electrical length ratio of the coupled line section to the transmission line section is approximately 1:2, and a distance from the first parallel stripe line 244 to the second parallel wire 245 is less than 10 μm. A width of the microstripe line 243 is less than that of the first and the second lead lines 246 and 247 .
[0021] [0021]FIG. 2B shows an equivalent circuit of the high-temperature superconductor low-pass filter in FIG. 2A.
[0022] As shown in FIG. 2B, the HTS high-temperature superconductor low-pass filter includes a first π type equivalent circuit portion 235 corresponding to the transmission line section 241 and a second π type equivalent circuit portion 234 corresponding to the coupled line section 242 .
[0023] Compared with the conventional low-pass filter shown in FIG. 1B, the high-temperature superconductor low-pass filter in accordance with the present invention further includes a third capacitor C R . That is, an inductor L R is disposed between the signal transmission input port and the signal transmission output port. A first capacitor C P1 is connected between the signal transmission input port and a ground, and a second capacitor C P2 is connected between the signal transmission output port and the ground. The third capacitor C R is connected in parallel with the inductor LR between the first and the second capacitors C P1 and CP 2 . The first and the second capacitors C P1 and C P2 are constituted with capacitors C C1 and C C2 which are physically isolated, respectively.
[0024] [0024]FIG. 2C shows an equivalent circuit of the high-temperature superconductor low-pass filter shown in FIG. 2B. As shown in FIG. 2C, the equivalent circuit diagram includes an inductor L 1 disposed between the signal transmission input port and the signal transmission output port, a first capacitor C 1 connected between the signal transmission input port and the ground, and a second capacitor C 2 connected between the signal transmission output port and the ground.
[0025] Such a low-pass filter has three attenuation poles due to the electrical length φ of the transmission line section and the coupled line section. Two attenuation poles are positioned at two points where a susceptance of a serial element becomes zero and one attenuation pole is positioned at a point where a susceptance of parallel elements becomes infinite.
[0026] [0026]FIGS. 3A to 3 C illustrate a schematic diagram, a basic circuit diagram and an equivalent circuit diagram of a seventh-order low-pass filter in accordance with the present invention, respectively.
[0027] Referring to FIG. 3A, the seventh-order low-pass filter includes a transmission line section 360 having three stripe lines and a coupled line section 370 having three pair of parallel stripe lines. Each stripe line is connected to each pair of the parallel stripe lines.
[0028] Compared with the high-temperature superconductor low-pass filter shown in FIG. 2A, three circuit patterns are serially connected between the signal transmission input port and the signal transmission output port.
[0029] [0029]FIG. 3B shows an equivalent circuit of the seventh-order low-pass filter in FIG. 3A. As shown, the seventh-order low-pass filter includes a first π type equivalent circuit portion 340 corresponding to the transmission line section 360 and a second π type equivalent circuit portion 350 corresponding to the coupled line section 370 . Three circuit patterns 310 , 320 and 330 are serially connected between the signal transmission input port and the signal transmission output port.
[0030] [0030]FIG. 3C shows an equivalent circuit of the seventh-order low-pass filter in FIG. 3B. Compared with the low-pass filter shown in FIG. 2C, the seventh-order low-pass filter includes three circuit patterns which are connected in series. Each circuit pattern includes an inductor L 1 disposed between the signal transmission input port and the signal transmission output port, a first capacitor C 1 connected between the signal transmission input port and the ground, and a second capacitor C 2 connected between the signal transmission output port and the ground.
[0031] According to a filter design of the present invention, respective parameters of the π type equivalent circuit are expressed as follows:
jω 0 C 1 =jω 0 C c +jω 0 C p (Eq. 1)
[0032] [0032] jω 0 C 1 = jω 0 C c + jω 0 C p ( Eq . 1 ) jω 0 L 2 = 1 jω 0 C r + 1 jω 0 L r ( Eq . 2 )
[0033] where, jω o C r =j (Y oo −Y oe )/2*tanφ, jω o L r =jZ o sin 2 φ. Here, ω 0 denotes a cutoff frequency of the proposed low-pass filter, C capacitance of low-pass filter, L inductance of low-pass filter, Y 00 an odd mode admittance of a coupled line, Y oe an even mode admittance of the coupled line, Y o a characteristic admittance and φ an electrical length of a coupled line.
[0034] Using a transmission line and coupled line theory together with the equations 1 and 2, a susceptance (an imaginary number portion of an admittance in relation to a conductivity) is expressed as follows:
1 jω 0 L n = j Y 00 - Y o e 2 tan φ - j Y 0 c s c2 φ ( Eq . 3 ) jω 0 C n = j Y o e tan φ + j Y 0 tan φ 2 ( Eq . 4 )
[0035] The low-pass filter expressed as these physical parameters has three attenuation poles due to the electrical length φ of the transmission line section and the coupled line section. Two attenuation poles are positioned at two points where the susceptance of serial elements in the equation 3 becomes zero and one attenuation pole is positioned at a point where a susceptance of parallel elements in the equation 4 becomes infinite.
[0036] Since the attenuation poles are dispersedly positioned at the stopband of the low-pass filter, the frequency range of the stopband is expanded up to ten times of the cutoff frequency. Also, a device size can be scaled down remarkably. That is, the positions and the number of the attenuation poles are controlled adjusting the electrical length of the transmission line section and the coupled line section, so that it is possible to implement the low-pass filter having a broad stopband.
[0037] [0037]FIG. 4A is a graph illustrating simulation results of the seventh-order low-pass filter which is designed to have five attenuation poles. A cutoff frequency of the seventh-order low-pass filter is 900 MHz with a ripple level of 0.01 dB. FIG. 4B is a graph illustrating simulation results obtained using an EM simulator in order to design actually the low-pass filter based on the simulation results.
[0038] As shown, the seventh-order low-pass filter in accordance with the present invention has a symmetrically elliptic low-pass characteristic at the center of 4 GHz. The attenuation poles are positioned at 1.5 GHz, 2.4 GHz, 3.8 GHz, 4.4 GHz and 6.1 GHz. The seventh-order low-pass filter exhibits an improved characteristic stopband in the range from 1 to 7 GHz at the cutoff frequency of 1 GHz.
[0039] [0039]FIGS. 5A to 5 F are cross-sectional views illustrating sequential steps associated with a method for fabricating the seventh-order low-pass filter.
[0040] Referring to FIG. 5A, a high-temperature superconductor (HTS) YBa 2 Cu 3 O 7-x (YBCO) epitaxial thin film 520 is grown on an MgO substrate 510 in a C-axis direction. Then, an Au/Cr film 530 is formed on the HTS YBCO epitaxial thin film 520 .
[0041] Referring to FIG. 5B, a photoresist 540 is formed on an entire structure using a spin coating method.
[0042] Referring to FIG. 5C, a predetermined portion of the photoresist 540 is removed through an exposure of an ultraviolet (UV) source to thereby form a photoresist pattern 550 and mask aligner to form a photoresist pattern 550 .
[0043] Referring to FIG. 5D, the HTS YBCO epitaxial thin film 520 with metal films 530 and photoresist pattern 550 is formed through the standard photolithographic and ion-milling etching processes.
[0044] Referring to FIG. 5E, after the photoresist pattern 550 is removed by acetone, an Au/Cr pad 530 is formed by using a lift-off method to good contact with a K-connector.
[0045] Referring to FIG. 5F, the groundplane 560 is fabricated by sputtering of the metal film (Cr/Ag film).
[0046] [0046]FIG. 6 shows comparison of the simulated and measured results of the seventh-order HTS coupled line low-pass filter. The measured results are identical to the EM simulations.
[0047] The HTS coupled line low-pass is fabricated using the HTS YBCO thin film grown on MgO substrate through surface treatment (polishing). Even if the HTS coupled line low-pass filters are fabricated as microstrip type, the microwave losses can be reduced considerably due to a very low surface resistance of HTS epitaxial films.
[0048] The planar type HTS coupled line low-pass filter for suppression of harmonics and spurious signals can be applied to the various wireless communication systems for the remarkable improvement of a skirt characteristic as well as a broadband harmonics rejection characteristic, and reduction of interferences and noises.
[0049] Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed is a high-temperature superconductor low-pass filter for removing broadband harmonics in a wireless communication system. The high-temperature superconductor low-pass filter includes a coupled line section and a transmission line section, in which the coupled line section is connected in parallel with the transmission line section. The coupled line section has two microstrip open-stub type parallel stripe lines stacked on a high-temperature superconductor, and the transmission line section has one stripe line. Since the high-temperature superconductor low-pass filter has attenuation poles at a stopband, it has stopband characteristics to 7-8 times wider than a cutoff frequency. The high-temperature superconductor low-pass filter can easily remove sub-harmonics which are inevitably occurred in the wireless communication system.
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FIELD OF THE INVENTION
This invention relates to the field of filtration of gases containing entrained particles. More particularly, this invention relates to an element in a filter assembly of the class of filter assemblies known as the "outside bag" filtration devices, to such devices containing such an element, and to the process of filtering gases using an assembly containing the element. This invention increases the operational life of filters used in the filtration of gases containing entrained particles.
BACKGROUND OF THE INVENTION
One widely used commercial design for removing particulate matter (dust) from gas streams utilizes a method which has been designated as the "outside bag" dust collection principle. In this design, dust-containing gas flows into a large compartment containing a plurality of long, substantially cylindrical filter bags, each bag being suspended by its ring-shaped top. A cylindrical wire cage internally supports the bag and prevents collapse of the filter bag when the gas is flowing into it. The dust collects around the outside of the bag, while the cleaned gas flows into and upward through the bag and out the top of the bag into the clean air outflow conduits. The dust collected on the outside surface of the bag is periodically removed by releasing a split-second reverse-flow pulse of compressed air into the top of the bag. The compressed air travels down the length of the bag, causing it to expand. When the pulse of reverse-flow air is stopped, the bag contracts against the cylindrical wire support cage. The expansion and the contraction of the bag causes the collected particles to fall off the bag and be collected. The pulses of reverse-flow air may also cause the bag to "grow" (increase in area of the fabric) over a number of cycles. The contraction against the cage causes the bag to abrade, and the abrasion becomes more severe if the bag grows irreversibly. The pulse of reverse-flow air is usually applied to one row of bags at a time in sequence so that the main flow of dust-containing air into the baghouse and clean air flow from it are not interrupted.
It is known to make the filter for "outside bag" filtration devices of poly(m-phenylene isophthalamide)--see Forsten U.S. Pat. No. 4,536,439, or poly(tetrafluoroethylene), or glass fiber, or blends of these and other fibers--see Forsten et al. U.S. Pat. No. 4,361,619.
Various means have been proposed in the past to increase operational life of the filters, for example, it has been suggested that the filter be made thicker so that it would take longer to wear through, and it has been suggested that the pulse of air that is released into the filter bag to shake off the particles be released through a multi-perforated hollow metal cylinder located inside the filter bag--this latter system is known commercially as the "Staclean" diffuser system.
DESCRIPTION OF THE INVENTION
It has now been found that the operational life of a filter can be increased by reducing the abrasion between the filter and the wire cage that supports the filter by first covering the cage with a highly gas permeable tubular textile of filamentary poly(tetrafluoroethylene) (sometimes hereinafter referred to as PTFE), and then applying the tubular filter bag in the usual fashion.
The tubular textile of filamentary poly(tetrafluoroethylene), reduces the abrasion in two distinctly different ways, first, it acts to prevent direct metal to filter contact and second, it lowers the extent to which the filter is pressed, by the gas to be filtered, into the interstices of the support cage. Thus, the abrasion is reduced and the filter is less likely to be stretched by pressure from the gas being filtered.
The tubular poly(tetrafluoroethylene) textile element of this invention is substantially nonrestrictive to gas flow, that is, it has a gas permeability of at least 1000 ft 3 per ft 2 per minute, measured at a pressure of inch of water (At least 300 m 3 per m 2 per minute at a p of 1 cm of water). Preferably, the tubular textile element has a basis weight of about 2 to about 6 oz per sq yd. (about 68 to about 204 g/sq. m). The tubular element may be made of poly(tetrafluoroethylene) monofilament or of multifilament yarn. Tubular elements made from monofilaments contain filaments of a linear density of about 100 denier (110 decitex) and larger, while the tubular elements made from multifilament yarns contain fibers of a denier per filament of less than 100, and the yarns have a linear density of 200 to 2000 denier --a decitex of 220 to 2200.
The filtering assembly which includes the poly(tetrafluoroethylene) elements comprises the supporting cage, the PTFE element and the filter bag. The supporting cage ma be formed of ferrous metal, i.e., soft steel rods or stainless steel, or steel with a chemically resistant coating--other abrasion resistant metals and metal alloys may also be used. The filter bag may be any known in the art, for example, PTFE bags, poly(m-phenylene isophthalamide bags, bags of blends of PTFE and glass fiber, acrylic fiber bags, bags of polyphenylene sulfide fiber, bags of glass fiber batts having abrasion resistant coatings such as poly-fluorocarbon coatings. See Forsten et al. U.S. Pat. No. 4,361,619. Such filter bags may be made with or without supporting scrims. The particular filter bag that will be used with the tubular element will depend on the particular gas to be filtered, the composition and size of the particles to be removed, the temperature of the gas and other factors.
The tubular textile elements may be fabricated by a tubular knitting process, to make an open knit or netlike structure or the tubular elements may be made by stitching an open weave fabric into a cylindrical (tubular) shape.
The tubular PTFE textile element may be made of monofilaments--i.e., filaments having a denier of at least 100 (decitex of at last 110), or of multifilament yarns in which the yarns are composed of filaments having a denier of less than 100 (decitex of less than 110). If multifilament yarns are used the yarns should have a denier in the range of about 200 to 2000 (decitex of about 220 to 2200).
The tubular textile of PTFE should have a weight in the range of about 2 to 6 oz per yd 2 (about 68 to 204 g/sq.m).
EXAMPLE
A filter cage having a length of 95 inches (241 cm) and a diameter of 4.75 inches (12.1 cm), made of 10 wires (4 mm in diameter) evenly spaced (1.5 inch=3.8 cm apart) that ran the length of the cage, and evenly spaced rings (4 inches=10 cm apart), was fitted with a tubular knitted textile of poly-(tetrafluoroethylene) made from yarn having a linear density of 1800 denier (1980 decitex). The textile had a weight of about 150 g/m 2 . The textile had an air permeability of about 1000 ft 3 per ft 2 per minute at a pressure of 1/2 inch of water (about 300 m 3 per m 2 per min. at a pressure of 1 cm of water. The tubular textile was about 20% larger in diameter than the cage. The cage was inserted in the tubular textile. The textile attached to the cage by a fixation ring at the top of the cage, and the lower end of the tubular textile which extended beyond the cage tied in a knot. The tubular textile was then heated to 300° C. for one hour. This caused the tube to shrink and assume the dimension of the cage. A standard filter bag was then superimposed over the tubular textile, and the assembly tested in gas filtration tests, using periodic internal gas pulses to remove particular matter from the outer surface of the bag, against control assemblies that did not contain the tubular poly(tetrafluoroethylene) textile. The assembly containing the tubular poly(tetrafluoroethylene) textile was superior to the control assemblies. It was also at least as good as any special assembly tested including assemblies containing internal air diffusers and assemblies having special cages containing a larger number of longitudinal wires and more evenly spaced rings.
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A tubular textile of filamentary poly (tetrafluoroethylene) useful to prolong the mechanical life of a filter material. An assembly for filtering comprising a cage, the tubular filamentary PTFE, and a superjacent filter.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/477,876, entitled “System and Method for Centralized Institution Admission Application Submission, Processing, Analysis, and Distribution”, filed on Jun. 12, 2003.
SEQUENCE LISTING OR PROGRAM
[0002] Not Applicable
FEDERALLY SPONSORED RESEARCH
[0003] Not Applicable
TECHNICAL FIELD OF THE INVENTION
[0004] This invention relates to the institution application process, and more specifically relates to streamlining the current application process from both the student and institution perspective by eliminating the process of duplication and inefficiency found in the prior art by incorporating a centralized collection system and improved allocation of applicant information.
BACKGROUND OF THE INVENTION
[0005] Each year over 2.3 million high school ( 649 ) seniors apply to one or more institutions or universities. Unfortunately, the excitement of applying to institution quickly fades as applicants face the reality of the current application process. The inefficiency of the current system results in the unnecessary stress and labor. Currently applicants ( 110 ) are required to, among other things: (A) fill in the same information ( 154 ) numerous times for each institution application, (B) spend an inordinate amount of time photocopying and assembling application packages, (C) make numerous calls and inquiries to each institution to which they applied to check on the status of the application, and (D) constantly track down recommendation letters and transcripts to make sure that applications are completed in a timely manner.
[0006] Under the current process, when an applicant ( 110 ) applies to three different institutions, Institution- 1 ( 116 ), Institution- 2 ( 117 ), and Institution- 3 , ( 118 ), she sends the same information ( 115 ) directly to each institution to individually process and evaluate for acceptance. Since almost all of the schools receive the same information and process it for the same core results, each institution ends up repeating the same identical work as the others as illustrated in FIG. 1.
[0007] The inefficiencies of the current system do not only impact the applicants. Institutions also become frustrated as they face the annual administrative burden of sifting through thousands of applications in search of a top-notch class. The frustration results from the fact that nearly 85% of the administrative process of receiving and evaluating applications is duplicated at each and every institution: from endless data entry and filing to answering numerous inquiries from applicants.
SUMMARY OF THE INVENTION
[0008] Inventor has devised a method and system of applying to institution that simplifies and streamlines the application process by centralizing administrative functions and thereby eliminating duplicative and repetitive efforts performed by both applicants and institutions. From the applicants' perspective, the system features an interview style application questionnaire ( 610 ). The answers to this questionnaire are then used to complete the core application ( 430 ). Some institutions may also have mini-supplements ( 450 ) that may ask additional institution-specific questions.
[0009] Further, the system centralizes most administrative functions of the institution application process. It does this by compiling all components of an application package and then distributes it to all the institutions to which an applicant applies. The system is designed to allow applicants to apply to additional institutions with ease, adding the benefit of larger application volumes for institutions.
[0010] Although others have invented institution application processes, the present invention is superior. From the viewpoint of an applicant the application process is simplified into a 5 -step process ( 401 ), and each applicant's questionnaire ( 610 ) is customized and automatically skips irrelevant questions. For example, if the applicant indicates that they have never had a job, the “list jobs” section is skipped. Additionally, the present invention eliminates redundant steps as it is process engineered toward the applicant's completion of each component only once, requires no photocopying or assembling of packages necessary, is customizable to specific institution requirements by enabling institutions that wish to ask additional questions to establish supplements ( 450 ), eliminates redundancy as supplements do not request any information already asked.
[0011] Applicants are empowered as the present invention enables them to view their real-time status of any application or component on one screen, without making numerous calls or inquiries to each institution, e-mail updates ( 618 ) are automatically sent when transcripts and recommendations are received and processed, status reminders ( 618 ) are automatically sent every week to notify applicants about incomplete components.
[0012] The present invention requires less paperwork for applicants by enabling them to prepare only one form and envelope for their high school ( 649 ) and each recommender ( 618 ) eliminating the need to worry about the shuffle of a paper trail. Electronic confirmations ( 618 ) eliminate the need for post office return receipt records and institution-sent status postcards and help is available 24 hours a day, 7 days a week and service representatives are available online via chat to assist applicants in navigating through the process. Applicants can ask account-specific questions via electronic mail with a guaranteed 24-hour response.
[0013] Other additional advantage of the present invention over the prior art are that no additional work is required to apply to additional institutions and a simple fee structure saves money as an applicant pays a low one-time service subscription fee and shares in the efficiency by paying discounted institution application fees.
[0014] The advantages from the viewpoint of a institution is a reduction or elimination of paper filings, entire application package is compiled electronically, all forms, transcripts and recommendations are scanned and available for viewing in their original formats, predictable processing and turnaround time, and all documents are opened, scanned and processed within 24 hours, eliminating the administrative lag before applications can be reviewed. Also, applicants know if an item has been misplaced, or “lost in the mail” since it is processed quickly and applicants are immediately notified of its arrival, all data and information are always sorted and displayed in the same predictable format, allowing reviewers to quickly identify key information, better data for analysis and quicker decisions, important grades and standardized tests are displayed in useful and intuitive graphs, which allow for easy trend identification and comparison among peers and the volume of applications allows system to compile a national data-set, providing an ability to benchmark applicants against students in their own high school ( 649 ), even if they do not apply to the same partner institutions.
[0015] Additional capabilities limited to data from applicants that use the system are: applicants' key metrics are also benchmarked against other applicants to partner institutions who apply through the system; the system can provide ranking of applicants within a high school ( 649 ) and institution's applicant pool for the year; best practices and customizable metrics Allow quick analysis; analysis software ( 607 ) automatically calculates a customized, institution-specific Academic Index based on standardized tests, subject tests, class rank and/or GPA. Each institution can select specific factors to include and the weight each carries which they know is Verified, Accurate and Credible. Documents received from recommenders and high school ( 649 ) officials are promptly acknowledged, confirmed and verified by a follow-up letter to reduce the possibility of fraud. Powerful Workflow Features Electronic “Reading Queues.” Applications can be assigned to a specific evaluator to create “electronic reading queues”.
[0016] The system supports progressive changes of status and “grading” to allow partner institutions to send specific applications to “the committee” or any other group, category or person a institution identifies. An end of year analysis comparison reporting is available. Institutions can identify how many of their applicants were accepted or rejected from other specific partners.
[0017] Other additional advantages of the present invention over the prior art are that the system uses less storage space since it does not create duplicates of the same information and compiles all components of an application process, not just those which can be filed electronically. It also allows applicants and their advocates (recommenders and school 10 officials) to send their information only once to the system instead of multiple copies to different places. The system of the present invention is also superior to paper-methods or in-house electronic methods employed by an individual institution since it is electronically backed-up and therefore provides information in the event of a hardware crash or some other type of disaster.
[0018] The system compiles status of all components in one centralized screen eliminating the need for individual institutions to send status updates or for applicants to request them. It allows a institution to create additional specific supplements that can be directly controlled and customized in the system by the institution thus saving money for applicants by charging discounted application fees. The system allows applicants to apply to additional schools without completing more paperwork while offering user support via 24-hour a day real-time chat. Finally, the system provides comparisons to other applicants to a institution and even to other students from a high school ( 649 ), even if they do not apply to the same institution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 illustrates the current process of applying to institution and processing an application;
[0020] [0020]FIG. 2 illustrates the general concept of the centralized system that streamlines the applicant and institution's process;
[0021] [0021]FIG. 3 illustrates the an overview of how the centralized system accomplishes the goal;
[0022] [0022]FIG. 4 illustrates a sample of the system's 5-step applicant process;
[0023] [0023]FIG. 5 illustrates a sample of the system's applicant file distribution to institutions;
[0024] [0024]FIG. 6 illustrates a typical applicant review screen as viewed by a partner institution;
[0025] [0025]FIG. 7 illustrates the user input and review screen as viewed by the applicant.
DETAILED DESCRIPTION OF THE INVENTION
[0026] In the following detailed description of the invention of exemplary embodiments of the invention, reference is made to the accompanying drawings (where like numbers represent like elements), which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, but other embodiments may be utilized and logical, mechanical, electrical, and other changes may be made without departing from the scope of the present invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
[0027] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well-known structures and techniques known to one of ordinary skill in the art have not been shown in detail in order not to obscure the invention.
[0028] Referring to the figures, it is possible to see the various major elements constituting the apparatus of the present invention. The invention is a method and process for a centralized institution admission application submission, processing, analysis, and distribution system for use over a multi-user electronic network such as the Internet, which incorporates a and applicant's view, partner institution view, and a secure server running the centralized system of the present invention. The major system elements consist of database server, multiple subsystems, and multiple users connected over a multi-user electronic network.
[0029] Now referring to FIG. 1, under the current process, when an applicant ( 110 ) applies to three different institutions, Institution- 1 ( 116 ), Institution- 2 ( 117 ), and Institution- 3 , ( 118 ), she sends the same information ( 115 ) directly to each institution to individually process and evaluate for acceptance. Since almost all of the schools receive the same information and process it for the same core results, each institution ends up repeating the same identical work as the others.
[0030] [0030]FIG. 2 illustrates a general concept for a centralized system the streamlines the applicant's and institution's admission process. In this scenario, the applicant ( 110 ) submits their information only once to a institution application processing service ( 224 ) that in turn electronically delivers an entire institution application to a partner institution ( 265 ).
[0031] The physical method of operation for the institution application processing service is illustrated in FIG. 3. The centralized admission processing system ( 604 ) is a system for collection, communication, storage, analysis, retrieval and delivery of information comprising an ultra-secure central server ( 601 ) having random access memory (RAM); a database ( 602 ) accessible by applicants, service provider ( 224 ), and partner institutions ( 605 ) through said central server ( 601 ) via internet and/or other web remote access systems; processing software ( 603 ) executing on said server ( 601 ) for receiving information for applications consisting of biographical information, fee information, institution selections for application, core application questionnaire information, transcripts, reports, recommendations, institution specific supplements, and other data associated with institution applications; said processing software ( 603 ) executing on said server ( 601 ) for storing received images on said database ( 602 ), said processing software ( 603 ) on said database ( 602 ) for executing on said server ( 601 ) for generating an index and electronic applicant file based upon the received information and for storing the selected information; said processing software ( 603 ) executing on said server ( 601 ) for receiving the information from applicant ( 610 ) and partner institution ( 605 ) through a communication link; said processing software ( 603 ) executing on the central server ( 601 ) for storing the information on said central database ( 602 ); software executing on server for automatically searching the index in response to a query; and software executing on said server for transmitting the information to the applicant or partner institution ( 605 ).
[0032] The system as previously described also contains analysis software ( 607 ) on server providing data analysis, graphical representation of grade and standardized test scores, compiling of a national data set compilation created from data stored in the database, applicant comparison against selected institution's other applicants found in the central database ( 602 ); ranking of applicants within a high school ( 649 ) and institution's applicant pool for that year based on data in the central database and continuously calculating national averages or other metrics.
[0033] The system as previously described contains said analysis software ( 607 ) additionally executing on server ( 601 ) partner institution ( 605 ) specific academic index base on standard test, subject test, class rank, and or GPA as designed by a partner institution ( 605 ) in the central database ( 602 ) and said processing software ( 603 ) for executing partner institution ( 605 ) and applicant ( 110 ) updating.
[0034] System as defined further compromising said processing software ( 603 ) executing on the server ( 601 ) with ability for authorizing transmitting of the information, and said processing software ( 603 ) with ability for verifying integrity of the authorized information using SSL encryption.
[0035] System also contains said analysis software ( 607 ) with: a method for periodically monitoring the information stored on the central database ( 602 ) to verify the stored data integrity; a method for periodically generating reports on the monitoring results for reference purposes; a method of periodically generating reports on the monitoring results for analysis purposes; a method for storing account and billing information accompanied by the delivery instruction in an account-billing sub-database.
[0036] Now referring to FIG. 4, the 5-step applicant process with respect to the method of operation for a centralized admission application submission is shown that may be utilized by institutions, universities or other educational institutions. First, applicants ( 101 ) register to use the centralized admission application service provider ( 224 ) through a secure Internet web portal ( 608 ) by submitting their information through an easy to use 05-step applicant dashboard web interface ( 609 ). The 5-step dashboard is a user interface designed as an interview style application where applicants simply answer questions to complete and track their applications.
[0037] The First Step ( 410 ) is where applicants complete a simple set up section that contains biographical and fee information. The Second Step ( 420 ) has applicants selecting the institutions to which they wish to apply ( 611 ). The Third Step ( 430 ) is completion of the core application that requires the input of information relevant to most standard and/or typical institution applications.
[0038] The Fourth Step ( 440 ) requires applicants ( 110 ) to print out PDF forms ( 613 ) which are completed and returned to the centralized admission processing system ( 604 ) and supply the applicants' electronic file with images of these PDF forms which are typically High school ( 649 ) transcripts, recommendation letters or other official reports. In an alternative embodiment of the present invention a control panel and access to the system is provided to a school officials who can input the request information into the system from a remote location via a multi-user network such as the Internet.
[0039] The Fifth Step ( 450 ) is the completion of partner institution specific mini-supplements. When all five steps are completed the applicant's electronic profile and application are sent/available to the selected partner institutions ( 605 ).
[0040] Now referring back to FIG. 3, documentation ( 615 ) such as recommendations that are not submitted through the web interface, but which is required, is provided to the applicant in step 613 through portable document format (PDF) forms, which can be downloaded online for completion at a later time. These forms provide a means of submitting information to the applicant's file. They include a privacy waiver, and the address to which they should be returned. Recommendation PDF forms and other supporting documentation or letters are mailed ( 613 ) directly to the centralized admission processing system's ( 604 ) processing department ( 639 ) by the Recommender ( 619 ) where they are received through mail delivery and processed ( 617 ) by the centralized admission processing system's ( 604 ) staff. Other evaluation and certification forms for such things as grade submission are also provided in PDF format so they can be delivered by the Applicant ( 110 ) to the evaluator ( 639 ), who will then submit them to centralized admission processing system's ( 604 ) database ( 602 ) directly.
[0041] Centralized admission processing system's ( 604 ) employees opening the mail envelopes and scanning them into digital form accomplish processing of this printed documentation. In the case of a recommendation, an electronic notice ( 618 ) is then generated in the Applicants ( 110 ) account to notify them that a document ( 615 ) has been received. Other evaluation and certification forms generate a confirmation notice ( 618 ) to the provider of the information ( 619 ) to confirm authenticity in addition to the Applicant's ( 110 ) notification of receipt. In both instances, the images are then electronically attached to the applicants file saving an exact copy of the image, which will later be transmitted to partner institutions as part of the applicants file. Original paperwork is archived for use at a later date or for verification if necessary.
[0042] Additionally, the centralized admission processing system ( 604 ) verifies the authenticity of documents through follow up measures, and enters data and metrics to create an applicant summary and graph interpretations of academic performance. Trained evaluators ( 639 ) read and enter data supplied by school counselors and officials such as evaluations, grades, and other certifications from the official PDF forms into the applicants account for analysis.
[0043] Applicant's file is maintained by centralized admission processing system's ( 604 ) database 2 electronically and provides the applicant ( 110 ), centralized admission processing system's ( 604 ) employees, and partner institutions ( 605 ) with automatic notifications ( 618 ) relevant to their requirements. Applicants are automatically notified of the file's current status, provided weekly updates of the files missing components, and may notify the applicant of an admission decision. Centralized admission processing system ( 604 ) receives automatic notification that marks applications as complete/ready for review and electronic reading queues to route for review.
[0044] Partner Institutions ( 605 ) are provided the applicant's complete file, which includes graphic interpretations of academic performance, comparing applicant to existing peer environment and competing applicant pool and offers. Additionally, the system automatically processes and accounts for application fees ( 620 ) that are then submitted to partner institutions ( 605 ) in an aggregate monthly payment ( 621 ). The centralized admission processing system's ( 604 ) effectively processes a student's application once and completes all the administrative work to obtain a complete application that can then be distributed to any number of partner institutions ( 605 ) reducing the redundancy of work by current institutions and students.
[0045] Partner Institutions also have the ability to create a Institution-Defined Customizable Academic Index ( 622 ) and supplemental questionnaires ( 623 ) for admission to their respective schools. The partner user interface ( 624 ) and access levels allow partner institutions to tailor applicant's submission requirements and to customize their analysis of the data with respect to their own custom academic index ( 622 ) and generate reports, graphs, and charts to illustrate the applicant data versus the institution's standards.
[0046] The Partner Institution's View is allowed three levels of access to the centralized admission processing system ( 604 ) and the applicant information contained therein. The three levels of access are Level 1 ( 626 ), Level 2 ( 630 ) and Level 3 ( 635 ).
[0047] Level 1 access ( 626 ) is typically granted to Admissions Directors or Designee who can add or change the mini-supplemental applications ( 623 ) for the institution, create institution-specific setting such as an Academic Index ( 622 ), download data for export to the institution's other system(s) ( 627 ), add and manage staff access ( 628 ), assign applications to electronic reading queues and categories ( 629 ), and perform the same functions ( 637 ) as all other access levels ( 625 ).
[0048] Level 2 access ( 630 ) is typically granted to a institution's application evaluators ( 631 ) can review all information and images of documents for applications in the assigned queues ( 632 ); view, print or download applications and summaries ( 633 ); change the status of all applications ( 636 ), and perform the same functions as Level 3 access ( 638 ).
[0049] Level 3 access ( 635 ) is typically reserved for administrative staff and restricted to the review of the status of all applications ( 634 ).
[0050] Now referring to FIG. 5, a copy of the applicant's electronic file ( 460 ) as delivered to a provider institution ( 605 ) is shown. Applicant's file ( 460 ) contains the applicant's: information ( 510 ), academic performance analysis ( 520 ) as set by the partner institution ( 605 ), high school ( 649 ) information ( 630 ), standardized test scores ( 540 ), personal family information ( 541 ), academic honors ( 542 ), extracurricular activities, work exp, etc ( 543 ), resume ( 544 ), essay ( 545 ), and application status ( 546 ).
[0051] Now referring to FIG. 6 a sample illustration of the review screen ( 700 ) as viewed by a partner institution ( 605 ). The screen ( 700 ) clearly shows the applicants name or other identifier ( 701 ) and their status ( 702 ) with the partner institution ( 605 ) reviewing the file. Any easy to use and well-known tab layout provides easy view of various subclasses in the applicants file. The current screen ( 700 ) illustrates what is likely to be found under the applicant's profile ( 713 ) and provides the applicant's personal information ( 703 ), contact information ( 704 ), educational data ( 705 ), test information ( 706 ), and family information ( 707 ). Additionally, the administrator could select any of the plurality of tabs located at the top of the screen ( 700 ) to view other important information about the applicant such as their submitted essay ( 708 ), transcripts ( 709 ), metrics ( 710 ), recommendations ( 711 ), and other notes ( 712 ).
[0052] Now referring to FIG. 7 the user input and review screen ( 750 ) as viewed by the applicant ( 110 ) is illustrated. In the sample review screen one can see how easily the applicant ( 110 ) is able to track what institutions ( 751 ) to which they intend to apply, the status of the information entered in their core application ( 752 ) and transcripts and recommendations ( 757 ). The core application ( 752 ) is further defined to inform the applicant ( 110 ) of which sections have not be started ( 753 ), which sections are partially complete ( 754 ) and which sections have been completed to date ( 755 ). The applicant also has the ability to view their entire application and make changes, corrections, or enter information. The transcripts and recommendations sections ( 757 ) enables an applicant ( 110 ) to quickly determine whom they have appointed to send recommendations and if there are received ( 759 ) as well as track the receipt of transcripts from one or more schools they have attended ( 758 ).
[0053] In another embodiment of the present invention the system may also exist where all confirmations and submissions occur electronically, either through a web-based interface, electronic mail, XML, FTP or other electronic standard, format or protocol.
[0054] In yet another embodiment of the present invention the system may also exist where standardized test scores are sent directly from the testing agency to the centralized admission processing system's ( 604 ) service to be compiled in the applicant's electronic file. The may also occur either on paper or electronically.
[0055] In still another embodiment of the present invention the system may also exist where the applicant does not interface with the system electronically and completes everything on paper to be sent to and processed by the centralized admission processing system's ( 604 ) staff and system. Likewise, it is possible for some parts to be paper-based while others are electronic.
[0056] In any embodiment of the present invention the system may also continuously compile an electronic credentials file that an applicant can use or build upon for later use (e.g.: applicant later decides to apply to transfer to another institution and the system still maintains their high school ( 649 ) records from the first time they applied).
[0057] It is appreciated that the relationships for the parts of the invention, to include variation in database and subsystem configuration to detach them for each other and provide the possibilities to deploy the system in different locations and under different authorities with division of labor, are deemed readily apparent and obvious to one of ordinary skill in the art, and all equivalent relationships to those illustrated in the drawings and described in the above description are intended to be encompassed by the present invention.
[0058] In addition, other areas of art may benefit from this method and adjustments to the design are anticipated. Many parts and processes of the system of the present invention may also be used for other application processes. This includes, but is not limited to: Law, Medicine, and Graduate School, Primary and Secondary Schools, Employment, Benefits, Scholarships, and other Credentialing Services. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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Today's institution application process distracts the resources of admissions offices with paper shuffling and processing away from the intellectual match-up of quality applicants and suitable higher education opportunities. The invention replaces this old way of doing things with a more efficient, unified system. This system uses the power of partnership to centrally collect and distribute application information. As a result, the system removes the duplicative administrative efforts, which happen concurrently at each institution, and delivers information and analysis far in excess of what each institution could provide independently.
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RELATED APPLICATIONS
The present application is a 35 U.S.C. §371 national phase application of PCT International Application No. PCT/US2013/048553, having international filing date of Jun. 28, 2013, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/666,104, filed Jun. 29, 2012, and U.S. Provisional Application Ser. No. 61/787,175, filed Mar. 15, 2013, the entire contents of each of which are incorporated by reference herein. The above-referenced PCT International Application was published as International Publication No. WO 2014/005011 A2 on Jan. 3, 2014.
BACKGROUND OF THE INVENTION
Dielectrics serve essential functions in devices, including microelectronic devices. Dielectric materials and films are electrical insulators which provide mechanical or structural support for electronic, mechanical, or electromechanical devices. Dielectric films are used to electrically and mechanically isolate electrical or microelectromechanical components from other device components or the outside environment. In this respect, the films must be of high mechanical quality and have a low or tunable dielectric constant. In addition, the ability to directly photo-pattern the dielectric film without the use of a temporary photoresist for pattern transfer is attractive due to the decreased time and cost requirements for device manufacturing. Negative-tone dielectrics often have good lithographic properties, but typically require organic solvents to develop the latent image. In addition, negative-tone materials often use a bright field mask where most of the mask is transparent. This leads to higher defect rates than dark field masks because particles on the mask have a high probability of resulting in component defects. Existing positive-tone dielectrics, however, have lithographic limitations. These limitations include poor patternability and low photo-speed because each chemical reaction requires at least one photon. Thus, thick dielectric films require very high optical doses.
Presently, the cost of lithographic tools significantly impacts on the cost of the final component. Furthermore, the nature of the developers used to develop the latent image also impacts the effect of the lithographic process on health, safety and environmental issues in the manufacture of such components. Organic solvents used to develop negative-tone, photosensitive dielectrics are often flammable, and are potentially hazardous to the health of the employees and to the environment. The use of aqueous developers is thus desirable because they are less hazardous to workers and the environment.
Polymers can generally provide the needed electrical, mechanical, and chemical properties with the added benefit of easy and low-cost processing. Some polymer dielectrics are photo-definable, which reduces the number and severity of the steps required to etch vias through the dielectric films. Positive-tone materials are more suitable for interlayer dielectric applications than negative-tone materials since positive-tone materials use mostly opaque masks, making photolithography less sensitive to particulates and increasing yield. Additionally, the ability to develop the latent image in an aqueous solution (e.g. aqueous base) reduces the need for environmentally harmful organic solvents.
A desirable combination of attributes for thick film, permanent dielectrics is to have positive-tone imaging, aqueous development, and high optical sensitivity and contrast. However, common diazoquinone (DQ)-containing, positive-tone materials have low sensitivity and photospeed due to the low quantum efficiency of DQ (Mack (1988) Applied Optics 27, 4913-4919). DQ also has a high absorption coefficient making exposure of thick films difficult. Fortunately, the absorption coefficient of the DQ photoproduct, indene carboxylic acid (ICA), is less than DQ, providing a photo-bleaching effect. However, thick films still require doses on the order of 100 to 1000 mJ/cm 2 (Maier (2001) Progress in Polymer Science 26, 3-65; Vleggaar et al. (1994) Journal of the American Chemical Society 116, 11754-11763; Mueller et al. (2012) Journal of Applied Polymer Science doi:10.1002/app.38055).
Chemically amplified (CA) mechanisms are a route to improving the photospeed compared to DQ-based systems. The most popular positive-tone CA systems are made possible by an acid catalyzed deprotection of a pendent functional group to cause a developer solubility switch, making the exposed regions soluble in aqueous base developer (Reichmanis et al. (1991) Chemistry of Materials 3, 394-407; Ito (2000) IBM Journal of Research and Development 44, 119-130). A functional group, such as an acid or alcohol, is called protected when it is in a different chemical form which can be readily converted into the deprotected form, acid or alcohol in this example. For example, tert-butoxycarbonyl (TBOC) and tert-butyl ester (TBE) are the protected forms of an alcohol and a carboxylic acid, respectively. When the TBOC or TBE is converted into an alcohol or carboxylic acid, respectively, it is called the action of “deprotection”. The addition and exposure of a small amount of a photoacid generator (PAG) can result in multiple deprotection reactions. The most common CA systems involve the deprotection of a TBOC or a TBE moiety to produce an alcohol or a carboxylic acid, respectively. The resulting deprotected groups are soluble in aqueous base developer whereas the unexposed regions remain insoluble. The high optical sensitivity of these mixtures enables thick film, positive-tone polymer films with good lithographic properties.
In order to obtain good mechanical and electrical properties in a permanent dielectric, it is often necessary to cross-link the polymer film. Cross-linking is the formation of a chemical bond, often a covalent bond between two previously unbounded moieties within the polymer mixture so that the average molecular weight of the polymer increases. Cross-linking usually improves the chemical or mechanical properties of the polymer, and can decrease its solubility in a solvent or developer. However, problems can arise with cross-linking in CA chemistries because many cross-linking mechanisms are acid catalyzed. For example, epoxy cross-linkers readily ring open in the presence of an acid and react with alcohols and carboxylic acids to form base-insoluble ethers and esters at low temperature, respectively (Raeis-zadeh, et al. (2011) Journal of Applied Polymer Science 120, 1916-1925; Parker & Isaacs (1959) Chemical Reviews 59, 737-799). Exposure and baking of a positive-tone CA film with multifunctional epoxy additives would cause the deprotection and immediate cross-linking of the exposed regions, leaving the exposed regions insoluble in the base developer.
Thus, there remains a need for chemical functionalities and a mechanism to enable preparation of positive-tone, aqueous-developable, CA, cross-linkable dielectrics.
SUMMARY OF THE INVENTION
To address this need, provided in an aspect of the invention is a composition for preparing a photo-patternable, high-sensitivity, positive-tone, permanent dielectric. Provided in another aspect of the invention is a photo-patternable, high-sensitivity, positive-tone, permanent dielectric. The high-sensitivity, photodefinability has been achieved in yet another aspect of the invention by a method of preparing a permanent dielectric by the use of a positive-tone, chemical amplification mechanism. In the chemical amplification mechanism, a photon absorbed by the photo-sensitive film generates a catalyst. The catalyst initiates a chemical reaction resulting in the formation of a latent image. The reaction product is soluble in an aqueous solution, such as aqueous base. In addition to forming a soluble product, the catalyst species is regenerated. Thus, each photon results in many chemical reactions in the chemically amplified system, rather than a single chemical reaction in a traditional photosensitive system.
The film of the invention may be used as a passivation layer of components in microelectronic devices. The high mechanical strength of the film of the invention may protect components in microelectronic devices from environmental damage. The low dielectric constant of the composition and film of the invention may facilitate electrically isolating components in microelectronic devices. This may result in lower electrical loss, permitting closer packed components and smaller devices.
The film of the invention may also be used as a thick film separator for a wide variety of mechanical, electrical, or electromechanical devices, including chip-stacking applications. Such may serve to thermally and electrically isolate devices while allowing for electrical connections to be made between the devices. Fabricating high-aspect ratio vias in a thick film may permit the use of through-silicon vias.
Further advantages provided by the composition and film of the invention may result in a much faster photo-speed than positive-tone dielectrics that presently exist. Less energy may be required for photo-patterning, and therefore higher throughput is possible. The present invention also permits the exclusion of epoxy-based cross-linkers, which may allow for compositions and films with lower dielectric constants. Additionally, the dielectric constant of the materials of the present invention may further be tuned by varying the polymer composition. Moreover, in that the materials of the present invention are positive-tone, fabrication may be facilitated of dielectric layers with holes to make electrical connections.
Thus, in one aspect, the present invention provides a composition for preparing a dielectric film comprising a polymer mixture, wherein the polymer mixture comprises:
a base polymer comprising a pendent protected organic functionality;
a photocatalyst for deprotecting the protected organic functionality; and
a chemical cross-linker for cross-linking the dielectric film after photo-patterning has taken place in an aqueous solution.
In another aspect, the present invention provides a dielectric film comprising a polymer mixture, wherein the polymer mixture comprises:
a base polymer comprising a pendent protected organic functionality;
a photocatalyst for activating the protected organic functionality; and
a chemical cross-linker for cross-linking the dielectric film after photo-patterning has taken place in an aqueous solution.
In yet another aspect, the present invention also provides a method of preparing a dielectric film comprising the steps of:
providing a base polymer comprising a pendent protected organic functionality and a photocatalyst for deprotecting the pendent protected organic functionality;
patterning the base polymer with a mask;
deprotecting the pendent protected organic functionality;
developing a positive-tone image in an aqueous base to provide a photo-pattern on the dielectric film; and
curing the dielectric film with a chemical cross-linker.
In still another aspect, the present invention also provides a dielectric film prepared by a method of preparing a dielectric film comprising the steps of:
providing a base polymer comprising a pendent protected organic functionality and a photocatalyst for deprotecting the pendent protected organic functionality;
patterning the base polymer with a mask;
deprotecting the pendent protected organic functionality;
developing a positive-tone image in an aqueous base to provide a photo-pattern on the dielectric film; and
curing the dielectric film with a chemical cross-linker.
These and other aspects of the invention are addressed in more detail in the drawings and description of the invention set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the images of hills (left) and trenches (right) of the patterned material made from poly(tert-butyl methacrylate) as the base polymer, Rhodorsil-FABA as the PAG, and a thermally-induced cross-linking compound, diazoquinone (DQ) as the cross-linking compound.
FIG. 2 shows DSC analysis of poly(TMBA-co-HEMA).
FIG. 3 shows TGA of a) neat poly(TMBA-co-HEMA) and b) poly(HMBA-co-HEMA) with PAG, exposed.
FIG. 4A shows the contrast curves for Formulation A.
FIG. 4B shows the contrast curves for Formulation B.
FIG. 5 shows developed trenches of the patterned material made from poly(TBMA-co-HEMA) as the base polymer, containing 1 pphr Rhodorsil FABA PAG (Formulation A).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The composition for preparing a photo-patternable, high-sensitivity, positive-tone, permanent dielectrics as set forth herein may comprise a base polymer, pendent protected organic functionalities, activators and cross-linking agents.
A variety of base polymers (photo-inactive polymer) may be used that are known within the art. Non-limiting examples of base polymers of the invention include polymethacrylate, polyacrylates, polystyrenes, polyimides, polyamides, polysiloxane, polysilsesquioxanes, and polynorbornenes. In a particular embodiment of the invention, the base polymer may be poly(tert-butyl methacrylate). In another embodiment, the base polymer may be poly(2-hydroxyethyl methacrylate). The base polymer may be synthesized from and contain one or more different and distinctive monomers. In some embodiments, the distinctive monomers are selected from the group consisting of acrylic, methacrylic and norbornene-type monomers. Accordingly, in an embodiment, the base polymer may be a copolymer of tert-butyl methacrylate and 2-hydroxyethyl methacrylate. In still another embodiment, the base polymer may be polynorbornene. The base polymer may have a pendent protected organic functionality comprising functional groups as a copolymer. Examples of monomers of such pendent protected organic functionalities include, but are not limited to TBOC or TBE. In another embodiment, the norbornene of the base polymer may be norbornene tert butyl ester (I). In a further embodiment, the norbornene of the base polymer may be norbornene hexafluoro-2-methyl-2-propanol (II). In still another embodiment, the base polymer may be a copolymer of (I) and (II).
Other protected organic functionalities may be used in different embodiments of the invention. In other embodiments of the invention, an aliphatic molecule with a radically-initiated or base-catalyzed cross-linking functionality may be used as part of the copolymer to provide better mechanical and dielectric properties. Mechanical and dielectric properties of the film of the invention may also be altered by varying the amount of monomer in the copolymer composition. The copolymer composition may also be used to reduce the volume change often observed in CA resists after the post-exposure bake and improve the dissolution properties of the film. Exemplary copolymer functional groups are shown in Table 1.
TABLE 1
Possible Monomer Functionalities
Monomer 1
Monomer 2
Polymer 1
TBE
Alcohol
Polymer 2
Carboxylic Acid
TBOC
Polymer 3
TBE
TBOC
Polymer 1 has a pendent alcohol functionality (HEMA) to the base polymer and a pendent carboxylic acid functionality. The carboxylic acid can be produced via the thermal deprotection of TBE on TBMA. This system was chosen because the volume change during deprotection is likely to be small. The deprotection of the TBE produces isobutylene whereas the deprotection of the TBOC produces both isobutylene and carbon dioxide. Polymer 2 is attractive if a lower temperature or shorter deprotection time is needed since the TBOC deprotection occurs more readily than that of the TBE (Waliraff et al. (1995) Proceedings of SPIE 2438, 182-190). However, having pendent carboxylic acid moieties on the base polymer may increase the uptake of aqueous base in unexposed regions, similar to other positive-tone systems that contain a pendent carboxylic acid (Mueller et al. (2012) Journal of Applied Polymer Science doi:10.1002/app.38055). This may lead to a higher degree of swelling and may distort the spatial resolution of the patterned film. Polymer 3 may have less uptake of aqueous base in the unexposed regions due to the lack of an acidic proton. Polymer 3 may also have the best contrast of the three polymers in Table 1 due to the largest change in solubility between the unexposed and exposed states. Additionally, a 1:1 ratio of the two monomers would decrease the number of unreacted monomers in the film after cross-linking. This can improve the material properties and the dielectric constant. However, since each monomer has to undergo a deprotection reaction, the volume change for Polymer 3 may be the largest.
Other embodiments of the invention may include a terpolymer of any of the three polymers listed in Table 1 with an additional unreactive monomer to improve the dielectric constant. A saturated hydrocarbon pendent group can serve this purpose. With this terpolymer, there would be more room to adjust the monomer ratios to achieve full cross-linking of the alcohol and carboxylic acid moieties while maintaining control of solubility and patternability. In yet another embodiment, small molecule cross-linkers can be added to the formulation. Depending on the base polymer, these can be multifunctional alcohols or multifunctional carboxylic acids. In some embodiments, the multifunctional alcohol or multifunctional carboxylic acid is alkoxylated. In other embodiments, the multifunctional alcohol or multifunctional carboxylic acid is acrylated. Small molecule cross-linkers allow for partial cross-linking of the unexposed films and lessen the volume change due to the deprotection reaction. For example, if the Polymer 2 formulation contained a small amount of glycol additives, a low temperature cure could be done to cross-link some of the carboxylic acid groups with the glycol additives. Subsequent deprotection of the TBOC moieties by exposure and baking would produce more alcohol groups, and a final cure would be done to complete the cross-linking reaction. In an embodiment, cross-linking of the polymer backbone/dielectric material is enabled by the inclusion of trimethylolpropane ethoxylate.
In still further embodiments of the invention, other suitable polymer backbones are available for use as a permanent dielectric. Further non-limiting examples of polymer backbones that are suitable as a thermally stable polymer backbone with good mechanical and electrical properties include: polystyrene; polyimide; polyamide; and/or polysilsesquioxane. A wide range of polymers used in fabrication of mechanical, microelectromechanical, and fluidic devices can be photoprinted. Superior photoprinting (e.g. photospeed through chemical amplification), and environmentally sound developing (e.g. aqueous developing) is preferred. In still further embodiments, polymers containing a wide variety of building blocks, such as: polyethylene; polypropylene; bisphenol-A; polyethylene oxide; polyethylene terephthalate; polyphenols; and/or polysiloxanes, can be functionalized or mixed with the chemical moieties described herein and patterned in a chemically amplified way and cross-linked as set forth herein.
Exemplary but non-limiting pendent protected organic functionalities as set forth herein may lack an acidic proton and are thus insoluble in aqueous base. In an embodiment of the invention, the polymer mixture also contains a photo-acid generator (PAG) as the activator or catalyst. A variety of PAGs may be used that are known with the art. Non-limiting examples of PAGs include tetrakis-(pentafluorophenyl)borate-4-methylphenyl[4-(1-methylethyl)phenyl]iodonium (Rhodorsil-FABA), tris(4-tert-butylphenyl)sulfonium tetrakis-(pentafluorophenyl) borate (TTBPS-FABA), triphenylsulfonium tetrakis-(pentafluorophenyl) borate (TPS-FABA), bis(4-tert-butylphenyl)iodonium triflate (BTBPI-TF), tert-(butoxycarbonylmethoxynaphthyl)-diphenylsulfonium triflate (TBOMDS-TF), N-hydroxynaphthalimide triflate (NHN-TF), diphenyliodonium perfluoro-1-butanesulfonate (DPI-NF), tris(4-tert-butylphenyl)sulfonium perfluoro-1-butanesulfonate (TTBPS-NF), N-hydroxynaphthalimide perfluoro-1-butanesulfonate (NHN-NF), N-hydroxy-5-norbornene-2,3-dicarboximide perfluoro-1-butanesulfonate (NHNDC-NF), bis(4-tert-butylphenyl)iodonium tris(perfluoromethanesulfonyl) methide, (BTBPI-TMM), bis(4-tert-butylphenyl)iodonium bis(perfluorobutanesulfonyl) imide (BTBPI-BBI), diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DPI-DMOS), bis(4-tert-butylphenyl) iodonium p-toluenesulfonate (BTBPI-PTS), a non-ionic PAG such as Ciba IRGACURE® PAG 263 (III) and bis(4-tert-butylphenyl)iodonium perfluoro-1-octanesulfonate (BTBPI-HDF).
In a particular embodiment, the PAG is Rhodorsil-FABA. In another embodiment of the invention, the PAG produces a strong acid upon irradiation with ultraviolet radiation. In yet another embodiment, the base polymer can be synthesized such that the conjugate base of the activated PAG is pendent on the base polymer. Having the conjugate base pendent on the base polymer prevents diffusion of the conjugate base to other regions of the polymer film, such as the non-irradiated region. If the conjugate base diffuses to the non-irradiated regions of the polymer, it could facilitate transport of the photo-generated acid to those regions through electro-static interactions between the anion (i.e. conjugate base) and cation (i.e. photoacid). In a particular embodiment of the invention, the ultraviolet radiation used is 248 nm in wavelength. The acid produced catalyzes a deprotection reaction of the pendent organic functionality, and development of a photo-pattern includes aqueous basic solutions. In an embodiment of the invention, deprotection of TBOC yields a base-soluble alcohol along with carbon dioxide and isobutylene reaction products (Scheme 1). In another embodiment of the invention, deprotection of TBE yields a base-soluble carboxylic acid and isobutylene (Scheme 2). In further embodiments of the invention, the catalyst may be a photo-base generator, wherein deprotection results in aqueous acid-soluble reaction products, wherein development may include acidic solutions.
In the embodiments set forth in Schemes 1 and 2, isobutylene and carbon dioxide are gaseous products which leave the film. This solubility change mechanism is chemically-amplified, as each acid molecule used to deprotect the TBOC or TBE functional groups is regenerated and thus serves the role of a catalyst. Chemical amplification provides an advantage because only a very small amount of PAG is necessary and thus does not alter the properties of the dielectric. Furthermore, the energy required for patterning is smaller than non-amplified systems (high photo-speed) in that smaller amounts of photoactive compound i.e., a catalytic amount, are needed for activation. Benefits provided include higher device throughput with the same processing tools, and ultimately providing lower fabrication costs. Low concentration of PAG loading results in a lower dielectric constant of the film because the properties of the base polymer may be optimized. Photoactive compounds typically contain conjugated moieties to absorb light which increases the available electron pathways and mobile charge carriers that raise the dielectric constant. Alternatively, aqueous acid-soluble forms of the deprotected base polymer may be used.
The base polymer according to the invention has appropriate electrical and chemical properties to be used as a permanent dielectric. The polymer film may then be cross-linked in a post-development or curing step. The film is cured after photo-patterning in order to give the film high mechanical strength and a low dielectric constant. Numerous cross-linking mechanisms may be used that are known within the art to create a stable, permanent dielectric after patterning which do not interfere with the chemically amplified patterning process in the preparation of permanent films of the invention. In an embodiment of the invention, it is desirable to have the films be initially insoluble in aqueous base in the unexposed form, followed by a reaction leading to a solubility switch when exposed to UV radiation. Prior to curing, in another embodiment, it is desirable to have both carboxylic acid and alcohol functionalities present, at least one on the base polymer. Non-limiting examples of cross-linking mechanisms that may be used including thermal cross-linking free radical initiated cross-linking, acid catalyzed cross-linking, base catalyzed cross-linking or a reaction, such as condensation, that involves a different thermally-induced reactive species, for example, via a Wolff rearrangement of an α-diazo ketone to form a reactive ketene. In a particular embodiment of the invention, cross-linking may take place by heating the polymer mixture in the presence of diazonaphthoquinone (DQ) results in a solvent-insoluble, or cross-linked, film. Insolubility of the cured film in organic solvents is indicative that cross-linking occurred.
In another embodiment, cross-linking of the base polymer/dielectric material may take place by free radical initiation. For example, alkenyl-substituted polymers, including the base polymer, may be added to the mixture. A free radical photo-initiator may be used to react with unsaturated alkenyl bonds pendent on the base polymer, or added as a mixture, resulting in cross-linking. A non-limiting example of a free-radical photo-initiator is bis˜2,4,6-trimethylbenzoyl-phenylphosphineoxide (Irgacure 819, Ciba Specialty Chemicals Inc.). Other examples of photo-active and thermally-active free radical initiators include, for example, azobisisobutyronitrile and benzoyl peroxide. The addition of unsaturated, for example alkenyl, pendent groups on the base polymer allows for cross-linking via a free radical polymerization mechanism. The conditions of the curing are subject to the radical initiator activation. For example, cross-linking can be initiated at a specific temperature after patterning by selection of a thermally generated free radical initiator. In further embodiments, cross-linking of functional groups may occur by acid catalysis, base catalysis, or a reaction, such as condensation, that involves a different thermally-induced reactive species such as a ketene, such as via a Wolff rearrangement of an α-diazo ketone. In still further embodiments, the radical- or base-generating cross-linking compound is photo-active at a wavelength other than that of the initial, chemically amplified reaction. In particular embodiments, this wavelength is 365, 405, or 436 nm. This provides the possibility that the polymer film is both positive- and negative-tone, which adds processing advantages for particular fabrication sequences. In still further embodiments, the cross-linking moiety comprises an epoxy group.
In other embodiments of the invention, the cross-linking mechanism is compatible with the traditional CA solubility switching mechanism and the cross-linking mechanism does not interfere with the acid-activated deprotection and subsequent development of polymers with pendent TBOC, TBE, or other protected functionalities. The cross-linking is enabled by the inclusion of an alcohol and a carboxylic acid as organic pendent groups on a polymer backbone. These functionalities can be on the original polymer or can be produced via the acid catalyzed deprotection. After the exposed portions of the film are removed by an aqueous base solution, the film can be cross-linked via the Fischer esterification of an alcohol and carboxylic acid, as shown in Scheme 3. This cross-linking mechanism does not interfere with the photo-patterning, because the esterification reaction is slow compared to the deprotection of the polymer at normal processing temperatures. The final cure should involve the continuous removal of water from the film since it is a product of the esterification. This can be done under an inert atmosphere at low temperatures or under normal atmospheric conditions at higher temperature (>100° C.).
In other embodiments, patternability and subsequent cross-linking take place on a random copolymer of tert-butyl methacrylate (TBMA) and 2-hydroxyethyl methacrylate (HEMA), shown following acid catalyzed deprotection in Scheme 4. In further embodiments, patternability and subsequent cross-linking take place on a random copolymer of norbornene t-butyl ester and norbornene hexafluoro-2-methyl-2-propanol. Unexposed films are insoluble in aqueous base. Incorporation of a PAG into the formulation and exposure to 248 nm radiation causes the aqueous base solubility switch. Films are effectively patterned at exposure doses characteristic of CA systems and then cross-linked during an extended cure at an elevated temperature.
In still further embodiments, the cross-linking mechanism is selected so that it is not catalyzed during creation of the latent image. As provided herein for a positive-tone, CA, aqueous-developable dielectric, a slower acid catalyzed cross-linking reaction can be used than the acid catalyzed deprotection reaction. If a fast cross-linking reaction were acid catalyzed, then the latent image would be insoluble in aqueous base. Photogenerated free radical initiators are also available. If these types of initiators were chosen so that they absorb at wavelengths different from the PAG exposure wavelength, a photo-induced cross-linking of the film can be performed. This two-photon process, using two different wavelengths of radiation, can allow for positive-tone patterning of the film at one wavelength followed by negative-tone cross-linking at a different wavelength.
In still further embodiments, cyclic ether rings have internal bond strain, which makes them easily activated and reactive once ring-opening has occurred, can be used for cross-linking. Cyclic ethers of varying number of carbon atoms and configurations, for example, epoxides, can be used for post-development curing of the photopatterned polymer. The degree of bond strain in the cyclic ether can be selected and the activation method can be chosen from known routes, such as thermal activation, chemical activation or photoactivation (at a wavelength different from that of patterning). The rate of cross-linking can be chosen so that it does not interfere with the chemically amplified photopatterning step.
In summary, it has been demonstrated that: (i) the patternability of a positive-tone, chemically-amplified dielectric that contains an additional cross-linking compound; (ii) the ability to cure this material with a thermal bake; and (iii) the possibility of cross-linking this type of material by a variety of mechanisms. The net result is a material with improved lithographic properties, and excellent mechanical and electrical properties.
Particular embodiments of the invention will now be described with reference to the following non-limiting examples.
Example 1
Chemically Amplified Patterning on a Random Copolymer of Norbornene t-Butyl Ester and Norbornene Hexafluoro-2-Methyl-2-Propanol
An oxide coated silicon wafer was treated with a 3-(trimethoxysilyl) propyl methacrylate solution (5 weight percent in acetone) for adhesion promotion. The wafer was baked at 100° C. for 120 s followed by rinsing with acetone to remove excess adhesion promoter. A film containing 3 parts Rhodorsil FABA photoacid generator (PAG) per hundred parts polynorbornene by mass was made by spin-coating onto the wafer. The wafer was soft baked at a temperature of 100° C. for 120 seconds. At this point, the film was insoluble in 0.26 N tetramethylammonium hydroxide (TMAH) developer.
The film, approximately 3 μm thick, was then exposed to 248 nm ultraviolet radiation using a variable density optical mask. The wafer was post-exposure baked at 110° C. for 30 s. The film was developed for 30 seconds in a 0.065 N TMAH developer solution. An unexposed film is insoluble in the developer whereas a fully exposed film, when the t-butyl ester has been converted to a carboxylic acid, is soluble in the aqueous base developer. The contrast and sensitivity, D 100 , were obtained from plotting the normalized film thickness versus logarithmic exposure dose and linearly fitting the curve near the D 100 . The contrast was 11.5, and the sensitivity was 155.7 mJ/cm 2 . At the D 100 exposure dose of 155.7 mJ/cm 2 of 248 nm radiation, the maximum incident dose corresponds to 1.94×10 17 photons/cm 2 or 3.23×10 −7 moles of photon per square centimeter. The UV dose was corrected for reflection from the air/quartz interface and the quartz/polymer interface. The air/quartz interface has a reflection coefficient of 0.053, and the quartz/polymer interface has a reflection coefficient of 0.001, assuming a polymer index of refraction of 1.5. Using an absorption coefficient for the PAG at 248 nm radiation of 0.452 μm −1 , 73% of the radiation was absorbed by the polymer film. The incident intensity was 1.94×10 17 photons/cm 2 . Correcting the incident intensity for reflections reduced the photon dose to 1.84×10 17 photons/cm 2 . Based on the absorption coefficient (73% absorbed, on-average), there were 1.34×10 17 photons/cm 2 absorbed in the film. There were 4.96×10 15 PAG/cm 2 . This gives an average of 27 photons/PAG at D 100 . Assuming the polynorbornene copolymer had 75 mole percent t-butyl ester norbornene polymer, and a film density of 1 g/cm 3 , there were 5.6×10 17 protected acid moieties/cm 2 . If every PAG was activated by the 27-fold excess of photons, this would result in 113 t-butyl ester groups per PAG. If all the PAG was not activated (which is possible), the number of t-butyl ester groups/PAG would be more than 113. This shows that each PAG likely activated many t-butyl ester groups, and the factor of 113 t-butyl ester groups/PAG is consistent with chemical amplification.
Chemical amplification was confirmed by investigating the weight loss during activation of the t-butyl ester, which results in the loss of the butylene group. Thermogravimetric analysis (TGA) was performed on two samples of the polynorbornene backbone polymer film to determine the mass of the photochemical reaction products. The two films were processed as above up to the exposure step. One of the samples was exposed and the other was not exposed. The TGA ramp rate was 5° C./min to reach the post exposure bake temperature, 110° C., which was maintained for 30 minutes. The unexposed sample was treated as a baseline for solvent loss and was subtracted from the mass loss of the exposed sample. The exposed sample showed a loss of 14.7 wt %, after accounting for solvent and moisture loss. Any weight loss from the exposed sample is assumed to be due to the butylene leaving group from the t-butyl ester starting material. If one photon caused one chemical reaction resulting in loss of one butylene group, the resulting weight loss would be 3 wt %. Thus, the 14.7 wt % loss corresponds to 5 chemical reactions per photon, confirming chemical amplification.
The patterned sample was exposed to 1000 mJ/cm 2 at 248 nm to activate the PAG. The sample was then cured at 256° C. for two hours. The sample was immersed in the TMAH developer solution and it was found not to dissolve. This indicates that the sample cross-linked during the cure via the Fischer esterification mechanism. An uncross-linked sample would be soluble in the developer. Samples cured at a lower temperature, where cross-linking did not take place, were soluble in TMAH.
Example 2
Film Prepared from TMBA, Rhodorsil-FABA and Cross-Linked with DQ
The mixtures were patterned with standard photoresist techniques. In this particular example, a mixture of poly(tert-butyl methacrylate) as the base polymer, Rhodorsil-FABA as the PAG, and a thermally-induced cross-linking compound, diazoquinone (DQ), were dissolved in propylene glycol monomethyl ether acetate solvent. The particular DQ used was 2,4-dihydroxybenzophenone esterified at ˜100% with 2,1,5-diazonapthoquinone sulfonic acid. The film mixture was cast from the organic solvent by spin-coating followed by soft-baking on a hotplate. The soft bake at 100° C. removed excess solvent after spin coating. Exposure to 248 nm light through a photomask resulted in acid generation by the PAG in the exposed regions creating the latent image. A post-exposure bake was necessary to complete the polymer deprotection and for acid diffusion. Subsequent development in aqueous base, 0.26 N tetramethylammonium hydroxide, dissolved the deprotected regions of the film, creating the positive-tone image of the photomask on the wafer. FIG. 1 shows the images of hills and trenches of the patterned material made from poly(tert-butyl methacrylate) as the base polymer, Rhodorsil-FABA as the PAG, and a thermally-induced cross-linking compound, diazoquinone (DQ) as the cross-linking compound.
Example 3
Film Prepared from TMBA:HEMA, Rhodorsil-FABA and Cross-Linked by Esterification
Characterization Equipment.
1 H-NMR spectra were recorded on a Varian Mercury Vx 400 MHz instrument. Spectra were recorded in CDCl 3 and the protonated solvent peak at 7.26 ppm was used as an internal standard. Molecular weight measurements were made by gel permeation chromatography (GPC), using a Waters 2690 separation module and a 2410 differential refractive index detector. These were connected to Waters Styragel columns (HP 1, HP 3, and HP 4), and THF was used as an eluent and solvent. Molecular weights were compared to polystyrene standards. Glass transition temperatures (T g ) were measured by differential scanning calorimetry (DSC) with a TA Instruments DSC Q20 equipped with a Q-series DSC pressure cell. Measurements were taken under an unpressurized, nitrogen atmosphere. DSC samples were heated to 160° C. at a rate of 10° C./min and then cooled to 60° C. to remove the thermal history. Samples were again heated to 160° C. at a rate of 10° C./min for T g measurements. Thermogravimetric analysis (TGA) was done with a TA Instruments TGA Q50. TGA samples were heated at 5° C./min to a final temperature of 500° C. Scanning electron microscopy (SEM) was performed on a Zeiss Ultra 60 SEM. Samples for SEM were coated with 18 to 20 nm of palladium using a Hummer 6 Sputterer to prevent charging during analysis.
Synthesis of Poly(TBMA-co-HEMA).
TBMA and HEMA monomers were purchased from TCI America and Alfa Aesar, respectively, and were filtered through alumina before use to remove inhibitors. Azobisisobutyronitrile (AIBN) was purchased from Sigma Aldrich. A 100 mL round bottom flask was loaded with THF (25.5 mL), TBMA (5 g, 35.2 mmol), HEMA (2.29 g, 17.6 mmol), AIBN (31.9 mg, 0.194 mmol), and a stir bar. The flask was purged with dry nitrogen gas for 30 min, and the clear solution was stirred at 60° C. for 23 hours. The polymer was precipitated in H 2 O (700 mL) from THF and collected on filter paper. The polymer was then precipitated in hexanes (750 mL) from THF, collected on filter paper, and dried in vacuo at 50° C. to yield a white powder in good yield (6.13 g, 83.8%).
Preparation of Thin Films.
Formulations were made containing 20 to 35 wt % poly(TBMA-co-HEMA) in propylene glycol monomethyl ether acetate (PGMEA) and various loadings of Rhodorsil FABA PAG (provided by Promerus, LLC). Films were cast by spin coating on a CEE 100CB spinner at a speed of 1500 to 2500 rpm onto untreated <100> silicon wafers. Thin films (<5 μm) were baked after spin coating at 100° C. for 1 min to remove residual solvent. Thicker films were baked after spin coating at 100° C. for 2 min.
Lithographic Property Measurements.
UV exposures were performed with an Oriel Instruments flood exposure source with a 1000 W Hg(Xe) broadband lamp filtered to 248 nm. A post exposure bake was performed at various temperatures and times to catalyze the deprotection reaction in exposed regions. The films were then developed in MF-319, a 0.26 N tetramethylammonium hydroxide (TMAH) developer. Contrast and sensitivity were measured by exposing 9 to 10 μm thick films through a variable density optical mask (Opto-line International Inc.). Thickness measurements were made with a VeecoDektak 3 profilometer, and the thickness was plotted against the logarithmic exposure dose. The contrast (γ) is defined as the slope of this curve, which was fitted in a linear least squares method nearest to D 100 (minimum dose at which 100% of film develops) (Plummer et al. (2000) Silicon VLSI Technology , Prentice Hall, Upper Saddle River, N.J.). Films were cured in a tube furnace under a N 2 atmosphere at 120° C. for 10 hours.
Stress Measurements.
Wafer curvature was measured with a Flexus Tencor Thin Film Stress Measurement System, Model F2320, equipped with a He—Ne laser. Deflection measurements were recorded over the middle 80 mm of a 100 mm Si wafer with 670 nm and 750 nm laser irradiation. The wavelength with the highest reflected intensity was used to prevent errors due to destructive interference. The thin film stress (σ) was calculated using Stoney's equation,
σ=( E /(1− v ))( h 2 /6 Rt )
Where E/(1−v) is the biaxial elastic modulus of the substrate, h is the substrate thickness, R is the effective radius of curvature of the substrate, and t is the film thickness. R is calculated by
1/ R= 1/ R 1 −1/ R 2
Where R 1 is the radius of curvature of the bare substrate and R 2 is the new radius of curvature after film deposition.
Poly(TBMA-co-HEMA).
A TBMA:HEMA random copolymer was synthesized for use in a chemically amplified, aqueous developable, cross-linkable system. The polymethacrylate backbone was chosen as a model backbone for exploring the CA patterning and cross-linking reactions. The same patterning and cross-linking reactions described herein may be transposed onto polymer backbones which qualify as permanent dielectrics. The polymer composition was found to be 68.7:31.3 TBMA:HEMA via 1 H-NMR peak integration. This composition was found to be insoluble in 0.26 N TMAH. The polymer was characterized by GPC to have a M n of 54,400 g/mol, of 151,100 g/mol, and a polydispersity of 2.78. This polydispersity is characteristic of free radical polymerization reactions (Odian (2004) Principles of Polymerization , John Wiley & Sons, Hoboken, N.J.). The T g of the poly(TBMA-co-HEMA) copolymer was found to be 123° C. as measured by DSC, as shown in FIG. 2 . This T g is adequate for film processing since it is above the post-exposure bake temperature at 100° C. to 110° C. for the acid catalyzed deprotection of TBMA. Reflow of the exposed films could degrade the spatial distribution of the photo-acid and degrade the lithographic critical dimensions. The TGA of the neat polymer revealed two decomposition temperatures. The first decomposition temperature (T d1 ) at 214.2° C. corresponds to the deprotection of the TBMA group. The mass percent decrease at T d1 was measured to be 28.1%, which agrees well with the theoretical value of 27.9% for the loss of isobutylene at this polymer composition. A second decomposition temperature (T d2 ) was observed at 378.7° C. due backbone degradation. TGA measurements were also performed on PAG-loaded formulations after spin coating, post apply bake, and blanket exposure. The presence of a photoacid causes a shift in T d1 to a lower temperature, 71.8° C., as shown in FIG. 3 .
Contamination of the spin-cast film by ambient organic base in the atmosphere can interfere with the CA mechanism of positive-tone resists. Trace amounts of base in the atmosphere can absorb at the solid/air interface and neutralize the acid photoproduct (MacDonald et al. (1991) Proceedings of SPIE 1466, 2-12; Kunz et al. (1993) Proceedings of SPIE 1925, 167-175). The atmospheric base can have a profound effect due to the catalytic nature of the deprotection reaction. A base-insoluble surface layer was observed on patterned films in the exposed regions due to organic base contamination in the ambient air, even though some carbon filtering of the air was implemented. The surface layer was easily removed by mechanical agitation of the film in the developer. This contamination can be further reduced by additional filtration of the air through activated carbon and limiting the exhaust of volatile bases into the air.
The contrast and sensitivity for two formulations of poly(TBMA-co-HEMA) were evaluated. Formulation A contained 1 pphr Rhodorsil FABA PAG, and Formulation B contained 3 pphr Rhodorsil FABA PAG, as listed in Table 2.
TABLE 2 Contrast Experiment Conditions Formulation A B PAG Loading (pphr) 1 3 Thickness (μm) 9.07 9.87 PEB Time (s) 120 120 Developing Time (s) 120 150
The contrast curves for Formulations A and B are shown in FIGS. 4A and 4B , respectively. In both cases, an insoluble layer was seen at doses above the conventional D 100 value, and the thickness of this layer decreased with higher dose. It is hypothesized that this layer is due to organic base adsorbed at the wafer surface. It was also observed that pre-rinsing the wafer in an acid solution can have a significant effect on the thickness of this layer. The processing of this technique has not been optimized. Formulation A was found to have a thick film contrast of 12.7 and a D 100 of 50.2 mJ/cm 2 . These are good values for positive-tone, thick film formulations. In Formulation B, the increased PAG loading caused the contrast to decrease to 5.1 and the D 100 to decrease to 31.2 mJ/cm 2 . The decrease in contrast is not desirable and can be attributed to higher acid diffusion into the unexposed regions or to the higher absorption coefficient of the film. The increase in sensitivity, however, is a favorable trait of Formulation B. FIG. 5 shows an SEM image of the patterned trenches in a Formulation A film. In FIG. 5 , the half-pitch of the trenches from bottom-to-top are 16, 12.5, and 10 μm. It can be seen that the high contrast of Formulation A produces a vertical sidewall profile.
The lithographic properties for other positive-tone, thick film, permanent dielectrics are presented in Table 3.
TABLE 3 Lithographic Property Comparison of poly (TMBA-co-HEMA) to Reported Positive-tone, Permanent Dielectrics Film Thickness D 100 Dielectric (μm) (mJ/cm 2 ) Contrast Polyimide 7.5 350 1.2 Benzocyclobutene 16.4 810 1.02 Formulation A 9.07 50.2 12.7 Formulation B 9.87 31.2 5.1
The CA system presented here has a much smaller D 100 value than photo-patternable polyimide (Jin & Ishii (2005) Journal of Applied Polymer Science 98, 15-21) or benzocyclobutene (So et al. (2001) “Benzocyclobutene-based polymers for microelectronics” Chemical Innovation 31, 40-47) dielectrics because of the reuse of the photogenerated acid catalyst. The DQ-based dielectrics are less efficient, because each photon can produce at most one chemical reaction. In addition, the absorption coefficient of DQ makes exposure of thick films difficult because the light intensity decreases exponentially with depth into the film. This also causes the contrast of these dielectrics to degrade with film thickness. The high exposure doses for DQ-based dielectrics results in regions that are partially exposed, containing both DQ and ICA (Mueller et al. (2012) Journal of Applied Polymer Science Ahead of Print doi:10.1002/app.38055). These regions have partial solubility in TMAH. Low loadings of the photoactive compound are necessary in the poly(TBMA-co-HEMA) system so that radiation can penetrate the entire depth of the film resulting in a reasonable exposure dose.
The chemical amplification mechanism can be demonstrated by comparing the number of chemical reactions to the number of photons absorbed. Assuming a density of 1.0 g/cm 3 , a 9.8 μm thick film of Formulation A contains approximately 4.8×10 −6 moles of the TBMA moiety and 9.7×10 −10 moles of PAG per square centimeter. A dose of 50.2 mJ/cm 2 of 248 nm radiation has a maximum incident dose of 1.04×10 −7 moles of protons per square centimeter. This means that less than 1 photon is required for every 46.3 TBMA moieties at these processing conditions. Although it is not expected that 100% of TBMA groups need to be deprotected for aqueous base solubility, the number of deprotections due to a non-catalytic photoreaction would be insufficient to cause the observed photopatterning. This shows that the solubility-switching reaction must be chemically amplified in nature.
Cross-Linking of Poly(TBMA-co-HEMA).
After developing, the patterned films were given a blanket exposure of 1000 mJ/cm 2 of 248 nm irradiation to activate the PAG in the undeveloped portions of film. This dose was chosen to ensure that all of the PAG is activated, however, a much smaller dose would suffice. The film was then cured at 120° C. for 10 hours in a nitrogen atmosphere to carry out the Fischer esterification reaction. These conditions were chosen to ensure full cross-linking of the film and continuous removal of water. After curing, the films were insoluble in 0.26 N TMAH, which is a good indication that the carboxylic acid and alcohol functionalities on the base polymer underwent the acid catalyzed Fischer esterification reaction. Films coated at thicknesses greater than ˜4 μm would crack during the cure step. This could be due to the large volume change during cross-linking or to a mismatch between the coefficients of thermal expansion for the film and the substrate. Films thinner than 4 μm were crack-free and had good film quality after curing. The mechanical properties and volume change of the film can be tuned by varying the polymer backbone or monomer ratio.
Cross-linking was confirmed by measuring the film stress before and after a thermal cure. A formulation of poly(TBMA-co-HEMA) with 5 pphr PAG was coated to a thickness of 3.94 μm, baked at 100° C. for 60 s, and given an exposure dose of 1000 mJ/cm 2 of 248 nm irradiation. A post-exposure bake of 110° C. for 60 s caused the film thickness to decrease to 3.01 μm. The stress of the coated wafer was calculated to be 6.2 MPa. The sample was then cured at 120° C. for 10 hr under ambient atmosphere. The thickness after cure was measured to be 2.77 μm. The final stress was calculated to be 17.9 MPa. The large increase in stress during the cure is a result of film cross-linking. A separate sample was processed under the same conditions as far as the post-exposure bake. After this, the sample was developed in 0.26 N TMAH to verify that these processing conditions did not result in cross-linking prior to curing.
Example 4
Cross-Linking of TBMA:HEMA, Rhodorsil FABA, Trimethylolpropane Ethoxylate and Cross-Linked by Esterification
Trimethylolpropane ethoxylate was added at 10 mass parts per hundred parts poly(TBMA-co-HEMA) to act as a cross-linking agent in the Fischer esterification reaction. The sample, which included 3 mass parts Rhodorsil FABA per hundred parts poly(TBMA-co-HEMA), was spin coated from PGMEA to a thickness of 11 μm, and soft baked at 100° C. for 2 minutes. The film was exposed to 248 nm UV radiation through a variable density mask and developed in 0.26 N TMAH for 202 seconds. The contrast and sensitivity (D100) were obtained by plotting the remaining film thickness against the logarithmic exposure dose and linearly fitting the curve near D100. The contrast was found to be 4.8 and the D100 was found to be 202 mJ/cm 2 . The patterned film was exposed to 1000 mJ/cm 2 of 248 nm radiation to activate the PAG and baked at 110° C. for 30 seconds to deprotect the TBMA. The sample was cured at 150° C. for 2 hours. After curing the sample, was insoluble in 0.26 N TMAH, showing that the film had cross-linked during cure.
Although selected embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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In microelectronic applications, it is often desired to deposit and pattern a permanent dielectric film in order to electrically and mechanically isolate components. Photo-patternable dielectrics are attractive for these uses because of their reduced time and cost requirements. These permanent dielectrics should be high-speed, positive-tone, and aqueous-developable. This type of patternability may be achieved by using a chemically amplified deprotection reaction of tert-butoxycarbonate or tert-butyl acrylate catalyzed by a photo-inducible acid. Provided herein are: a composition for preparing a dielectric film comprising a polymer mixture, wherein the polymer mixture comprises a base polymer comprising a pendent protected organic functionality, a photocatalyst for deprotecting the protected organic functionality and a chemical cross-linker for cross-linking the dielectric film after a photo-patterning has taken place in an aqueous solution; a dielectric film prepared from said composition; and method of preparing a dielectric film.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to British Patent Application No. 1110996.4, filed Jun. 28, 2011, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The technical field relates to an internal combustion engine, particularly an internal combustion engine of a motor vehicle, equipped with a fluid tank and a discrete level sensor.
BACKGROUND
Internal combustion engines are conventionally equipped with a variety of fluid tanks, for example a fuel tank or an urea tank containing urea solution used in the exhaust gas treatment system, for which it is desirable to monitor to some degree the level of the fluid within. Continuous fluid level sensors have widely been used for detecting the level of fluid in a tank. They work by continuously measuring a level within a specified range and determining the exact amount of fluid in the tank as a function of the measured level. Unfortunately these sensors are relatively expensive. As alternative to continuous sensors, discrete level sensors could also be used. Discrete level sensors provide information on the level of fluid in the tank by simply indicating whether the fluid in the tank is above or below predetermined level threshold values. Discrete level sensors are therefore less precise since they are unable to detect the precise level of fluid between two level threshold values. Also when used in internal combustion engines they present additional problems. During transitory driving states of the vehicle, i.e., for example, during acceleration or deceleration, discrete level sensors provide level indications which are often misleading. In those situations the fluid in the tank is sloshed around and the level threshold values are randomly exceeded so that the sensor provides conflicting information regarding the actual level of the fluid in the tank. This is even truer when the discrete level sensors are used, for example, to detect the level of urea in urea tanks. Such tanks normally have a relatively flat and wide parallelepiped shape and small movements of the vehicle are enough to cause the fluid to slosh in the tank and to randomly exceed or fall below various threshold level values.
In view of the above, it is at least one object of an embodiment herein to provide a method to determine in a substantially precise way the fluid level in a fluid tank equipped with a discrete level sensor.
Another object of an embodiment herein is to provide a method for determining a fluid level which is substantially reliable even in transitory driving conditions.
Another object of an embodiment herein is to achieve the above mentioned objects in a simple, rational and inexpensive way without using complex devices and by taking advantage of the computational capabilities of an Electronic Control Unit (ECU) of the vehicle.
These objects are achieved by a method, by an engine, by a computer program and computer program product, by an electromagnetic signal, and by an automotive system having the features recited in the independent claims. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
In greater details, an embodiment herein discloses a method for determining a fluid level value in a fluid tank of an internal combustion engine equipped with a discrete level sensor, wherein the discrete level sensor is configured for:
generating a first electrical signal when a fluid level is above or equal to a first predetermined fluid level threshold value (LT 1 ), generating at least a second electrical signal when the fluid level is above or equal to a second predetermined fluid level threshold value (LT 2 ), the second predetermined fluid level threshold value (LT 2 ) being greater than the first predetermined fluid level threshold value (LT 1 ), and wherein the method comprises the steps of: monitoring a number of occurrences of the first and of the second electrical signal over a time interval; and calculating the fluid level in the fluid tank ( 500 ) as a function of the monitored number of occurrences of the first electrical signal and of the monitored number of occurrences of the second electrical signal over the time interval.
In this way, the level of fluid in a tank equipped with a discrete level sensor can be precisely calculated as a function of the signals generated by the sensor, and a reliable and precise information on the fluid level in the fluid tank can be obtained even in transitory conditions of the vehicle.
According to an embodiment, the fluid level in the fluid tank is calculated as a weighted average of the predetermined fluid level threshold values, each threshold value being weighted by the number of occurrences of the corresponding electrical signal.
In this way it is possible to determine the fluid level by using a simple calculation which can be easily implemented using the capabilities already present in the ECU of an internal combustion engine.
According to another embodiment, a fluid level threshold value is disregarded in the calculation of the fluid level if the corresponding monitored number of occurrences is below a predetermined occurrence threshold value
The methods of the various embodiments can be carried out with the help of a computer program comprising a program-code for carrying out all the steps of the methods described above, and in the form of a computer program product comprising the computer program.
The computer program product can be embodied as an internal combustion engine provided with a discrete level sensor and a ECU in communication with the discrete level sensor, a memory system associated with the ECU, and the computer program stored in the memory system, so that, when the ECU executes the computer program, all the steps of the method described above are carried out.
The method can be also embodied as an electromagnetic signal, the signal being modulated to carry a sequence of data bits which represent a computer program to carry out all steps of the method.
An embodiment further provides a control apparatus for an internal combustion engine equipped with a fluid tank and a discrete level sensor, the control apparatus comprising an Electronic Control Unit in communication with the discrete level sensor, a memory system associated with the Electronic Control Unit and a computer program stored in the memory system.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
FIGS. 1 and 2 are schematic representations of an automotive system comprising an internal combustion engine;
FIG. 3 is a schematic representation of a fluid tank equipped with a discrete level sensor; and
FIG. 4 is a schematic representation of the method according to an embodiment contemplated herein.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
Various embodiments contemplated herein may include an automotive system 100 , as shown in FIGS. 1 and 2 , that includes an internal combustion engine (ICE) 110 having an engine block 120 defining one or more cylinder 125 having a piston 140 coupled to rotate a crankshaft 145 . A cylinder head 130 cooperates with the piston 140 to define a combustion chamber 150 . A fuel and air mixture (not shown) is disposed in the combustion chamber 150 and ignited, resulting in hot expanding exhaust gasses causing reciprocal movement of the piston 140 . The fuel is provided by a fuel injector 160 and the air through an intake port 210 . The fuel is provided at high pressure to the fuel injector 160 from a fuel rail 170 in fluid communication with a high pressure fuel pump 180 that increases the pressure of the fuel received from a fuel source 190 . Each of the cylinders 125 has at least two valves 215 , actuated by a camshaft 135 rotating in time with the crankshaft 145 . The valves 215 selectively allow air into the combustion chamber 150 from the port 210 and alternately allow exhaust gases to exit through a port 220 . In some examples, a cam phaser 155 may selectively vary the timing between the camshaft 135 and the crankshaft 145 .
The air may be distributed to the air intake port(s) 210 through an intake manifold 200 . An air intake duct 205 may provide air from the ambient environment to the intake manifold 200 . In other embodiments, a throttle body 330 may be provided to regulate the flow of air into the manifold 200 . In still other embodiments, a forced air system such as a turbocharger 230 , having a compressor 240 rotationally coupled to a turbine 250 , may be provided. Rotation of the compressor 240 increases the pressure and temperature of the air in the duct 205 and manifold 200 . An intercooler 260 disposed in the duct 205 may reduce the temperature of the air. The turbine 250 rotates by receiving exhaust gases from an exhaust manifold 225 that directs exhaust gases from the exhaust ports 220 and through a series of vanes prior to expansion through the turbine 250 . The exhaust gases exit the turbine 250 and are directed into an exhaust system 270 . This example shows a variable geometry turbine (VGT) with a VGT actuator 290 arranged to move the vanes to alter the flow of the exhaust gases through the turbine 250 . In other embodiments, the turbocharger 230 may be of fixed geometry and/or include a waste gate.
The exhaust system 270 may include an exhaust pipe 275 having one or more exhaust after-treatment devices 280 . The after-treatment devices may be any device configured to change the composition of the exhaust gases. Some examples of after-treatment devices 280 include, but are not limited to, catalytic converters (two and three way), oxidation catalysts, lean NOx Traps, hydrocarbon adsorbers, selective catalytic reduction (SCR) systems, and diesel particulate filters. Other embodiments may include an exhaust gas recirculation (EGR) system 300 coupled between the exhaust manifold 225 and the intake manifold 200 . The EGR system 300 may include an EGR cooler 310 to reduce the temperature of the exhaust gases in the EGR system 300 . An EGR valve 320 regulates a flow of exhaust gases in the EGR system 300 .
The automotive system 100 may further include an electronic control unit (ECU) 450 in communication with one or more sensors and/or devices associated with the ICE 110 . The ECU 450 may receive input signals from various sensors configured to generate the signals in proportion to various physical parameters associated with the ICE 110 . The sensors include, but are not limited to, a mass airflow and temperature sensor 340 , a manifold pressure and temperature sensor 350 , a combustion pressure sensor 360 , coolant and oil temperature and level sensors 380 , a fuel rail pressure sensor 400 , a cam position sensor 410 , a crank position sensor 420 , exhaust pressure and temperature sensors 430 , an EGR temperature sensor 440 and an accelerator pedal position sensor 445 . Furthermore, the ECU 450 may generate output signals to various control devices that are arranged to control the operation of the ICE 110 , including, but not limited to, the fuel injectors 160 , the throttle body 330 , the EGR Valve 320 , the VGT actuator 290 , and the cam phaser 155 . Note, dashed lines are used to indicate communication between the ECU 450 and the various sensors and devices, but some are omitted for clarity.
Turning now to the ECU 450 , this apparatus may include a digital central processing unit (CPU) in communication with a memory system and an interface bus. The CPU is configured to execute instructions stored as a program in the memory system, and send and receive signals to/from the interface bus. The memory system may include various storage types including optical storage, magnetic storage, solid state storage, and other non-volatile memory. The interface bus may be configured to send, receive, and modulate analog and/or digital signals to/from the various sensors and control devices. The program may embody the methods disclosed herein, allowing the CPU to carryout out the steps of such methods and control the ICE 110 .
A fluid tank in the internal combustion engine, such as the fuel source 190 or an urea solution tank associated to the SCR 280 , can be equipped with discrete level sensors. The fluid level in the tank is generally sensed by obtaining a discrete indication, such as an electrical signal, whenever a predetermined threshold value has been reached, for example whenever the quantity of fluid in the tank exceeds a predetermined quantity. Fluid level sensors make use of various kinds of float operated mechanisms, resistance mechanisms, capacitative mechanisms, and acoustic mechanisms. A commonly used fluid level sensor is a magnetic float sensor which is very popular because of its simplicity, dependability and low cost. An example of a magnetic float discrete level sensor will now be described in more details with reference to FIG. 3 which is a schematic representation of a fluid tank 500 , in the present example, the urea solution tank, equipped with such a sensor 510 . The sensor 510 comprises a magnetic float 513 , annularly shaped, movably supported on an exterior of a tube 511 . The float 513 is adapted to be buoyant in the fluid and to move upwards and downwards along the tube with changing the fluid level in the tank 500 . A stop element 514 is located at the top of the tube 511 to stop the magnetic float 513 from being detached from the sensor 510 .
The sensor 510 further comprises a switch assembly 512 supported inside the tube 511 . The switch assembly 512 comprises a plurality of switches, each located at a different position along the tube 511 , each adapted to be magnetically activated when the magnetic float 513 , moving along the length of the tube 511 , reaches its level position. Each switch therefore corresponds to a fluid level threshold value in the tank. In FIG. 3 four fluid level threshold values are represented but the sensors can comprise from 2 to a plurality of switches and corresponding threshold level values.
The switch assembly 512 also comprises a plurality of resistors, each resistor in parallel to a switch. Whenever a switch is actuated the corresponding resistor is bypassed. A constant voltage, for example 5V, is applied to the switch assembly 512 via a constant voltage generator (not shown). The switch assembly 512 is then connected to the ECU 450 which is configured to receive an electrical signal from the sensor 510 , for example a percentage of the voltage value applied to the sensor 510 , which is a function of the number of bypassed resistors i.e., of the number of actuated switches.
When the fluid in the tank reaches a certain quantity corresponding to a level threshold value, the magnetic float 513 actuates the corresponding switch and a corresponding electrical signal is generated and sent to the ECU 450 . If the fluid in the fluid tank 500 is calm the magnetic float 513 is also stable along the tube 511 and the signal received by the ECU 450 is constantly the same until the level of fluid changes.
In normal operation, when the vehicle is moving, the fluid in the tank also moves around. It can be observed that in those circumstances the electrical signal produced by the sensor in a time interval, for example in the range of about 20 seconds, is not constant. The ECU 450 will actually receive a combination of electrical signals each corresponding to a level threshold value. The different electrical signals could be represented by the same signal with a different value of a characterizing parameter, i.e. frequency or amplitude. The method according to an embodiment will now be described with reference to FIG. 4 .
In particular, the actual fluid level in the fluid tank 500 can be determined by the ECU 450 by monitoring the occurrences of each electrical signal in that time interval (block 1 ). The time interval can be determined in a preliminary calibration phase and it can correspond to the time needed to fill in a dedicated buffer (not shown) in the memory system 451 .
A preliminary selection can be carried on the monitored occurrences on each electrical signal (block 2 ). In particular before calculating the fluid level the threshold values having a number of occurrences below a predetermined number of occurrences threshold value can be discarded. The number of occurrences threshold value, generally very small, can be determined in a calibration phase. This additional filtering step allows discarding samples only occurring sporadically in the time interval. In his way spikes due to sloshing of the fluid are detected and discarded.
The fluid level in the tank is then calculated (block 3 ) as the weighted average of the threshold level values, each weighted by the number of occurrences of the corresponding electrical signal. In particular:
L
=
Th
1
*
n
1
+
Th
2
*
n
2
+
…
+
Th
1
*
n
z
n
1
+
n
2
+
…
+
n
z
wherein L represents the calculated fluid level, This represents the threshold level values from i to z, and ni represents the corresponding number of occurrences.
In case of transitory driving conditions causing sloshing of the fluid in the fluid tank 500 the signal provided by the sensor 510 can change very quickly. This occurs for example when the sensor 510 is located in a fluid tank 500 of a vehicle which is accelerating or decelerating and the fluid in tank 500 is slammed from side to side. In such circumstances the magnetic float 513 moves along the tube 511 rapidly and the signal generated by the sensor 510 changes rapidly.
Even in those situations the fluid level can be calculated using the above formula. Furthermore, during the preliminary filtering step (block 2 ), spikes due to sloshing of the fluid are detected and discarded.
The method described above can be repeated once the time interval elapses, or the corresponding buffer is full, so as to continuously provide information on the fluid level.
While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.
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A method for determining a fluid level value in a fluid tank of an internal combustion engine equipped with a discrete level sensor is provided. The discrete level sensor is configured for generating a first electrical signal when a fluid level is above or equal to a first predetermined fluid level threshold value and generating a second electrical signal when the fluid level is above or equal to a second predetermined fluid level threshold value. The second predetermined fluid level threshold value is greater than the first predetermined fluid level threshold value. The method includes monitoring a number of occurrences of the first electrical signal and of the second electrical signal over a time interval. The fluid level in the fluid tank is calculated as a function of the number of occurrences of the first and of the second electrical signals over the time interval.
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CROSS REFERENCE TO RELATED APPLICATION
The present application is a divisional of U.S. application Ser. No. 09/696,208, filed Oct. 26, 2000 now U.S. Pat. No. 6,575,159, which claims priority from U.S. Provisional patent application Ser. No. 60/162,133, filed Oct. 29, 1999. The disclosure of the above-referenced provisional patent application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a portable liquid oxygen unit.
2. Description of the Background Art
Therapeutic oxygen is the delivery of substantially pure oxygen to a patient in order to facilitate breathing. When a patient suffers from pulmonary/respiratory problems, delivery of oxygen helps the patient get an adequate level of oxygen into his or her bloodstream.
Therapeutic oxygen may be warranted in cases where a patient suffers from a loss of lung capacity. Medical conditions that may make oxygen necessary are chronic obstructive pulmonary disease (COPD), including asthma, emphysema, etc., as well as cystic fibrosis, lung cancer, lung injuries, and cardiovascular diseases, for example.
Related art practice has been to provide portable oxygen in two ways. In a first approach, compressed oxygen gas is provided in a pressure bottle, and the gas is output through a pressure regulator and a hose to the nostrils of the patient. The bottle is often wheeled so that the patient may be mobile. The drawback of compressed, gaseous oxygen is that a full charge of a bottle that is portable does not last very long.
In order to get around this limitation, in a second approach a related art liquid oxygen (LOX) apparatus has been used wherein LOX is stored in a container and the gaseous oxygen that evaporates from the LOX is inhaled by the patient.
The related art LOX apparatus enjoys a longer usable charge than the compressed gas apparatus for a given size and weight, but has its own drawbacks. LOX, being a liquid that is very cold, requires a vacuum-insulated container.
Related art portable LOX units typically are formed with necks that can fill with LOX when tipped, and thus are to be used and carried only in a generally vertical position. This can be impractical at times, such as when driving a vehicle, for example. A vertically positioned related art portable LOX unit is unstable and could potentially cause problems for both the oxygen user and for other drivers if it shifts, slides, or tumbles.
There remains a need in the art, therefore, for an improved portable LOX unit.
SUMMARY OF THE INVENTION
A portable liquid oxygen (LOX) storage/delivery apparatus is provided according to the invention. The portable liquid oxygen (LOX) storage/delivery apparatus comprises an insulated (LOX) container having an interior for containing LOX, the LOX container having a top portion, a bottom portion and a sidewall between the top and bottom portions, the sidewall including a first side portion extending between the top portion and the bottom portion of the container, and a second side portion extending between the top portion and the bottom portion of the container, the second side portion being on an opposite side of the container from the first side portion, a port system in communication with the interior of the container for charging the container with LOX, and for withdrawing LOX and gaseous oxygen from the container, wherein the gaseous oxygen is withdrawn from the container through a first outlet communicating with the interior of the container, the first outlet being located adjacent a first juncture between the top portion and the first side portion of the container; wherein LOX is withdrawn from the container through a second outlet communicating with the interior of the container, the second outlet being located adjacent a second juncture between the bottom portion and the second side portion, and wherein gaseous oxygen can be withdrawn from the container through the first outlet and LOX can be withdrawn from the container through the second outlet when the container is positioned in a first orientation with the sidewall vertically oriented, as well as when the container is positioned in a second orientation with the second side portion oriented downwardly and with the first side portion oriented upwardly and overlying the second side portion, and in all positions in between.
The above and other features and advantages of the present invention will be further understood from the following description of the preferred embodiment thereof, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows one embodiment of a portable liquid oxygen unit of the present invention in a first position;
FIG. 2 schematically shows an alternate position of the portable LOX unit illustrating how the portable LOX unit of the present invention may be used in different orientations;
FIG. 3 schematically shows a detail of an insulated support system of the present invention; and
FIG. 4 schematically shows the portable LOX unit of the present invention being used in a portable LOX system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows one embodiment of a portable liquid oxygen unit 100 of the present invention. The portable LOX unit includes an outer shell 101 and a container 104 within the outer shell 101 .
A space 110 exists around the container 104 and is preferably evacuated to at least a partial vacuum. In the illustrated embodiment, the container 104 is held and supported within the outer shell 101 by an optional top support 118 and an optional bottom support 119 (discussed below in conjunction with FIG. 3 ). The container 104 may be insulated or may be formed of a material having heat insulating properties.
The container 104 is formed of a top portion 105 , a bottom portion 106 , and a sidewall 107 . The sidewall 107 includes a first side portion 108 and a second side portion 109 , both extending between the top portion 105 and the bottom portion 106 , but with the second side portion 109 being on an opposite side of the container 104 from the first side portion 108 .
The container 104 also includes a liquid withdrawal conduit 113 and a gaseous withdrawal conduit 116 . The gaseous withdrawal conduit 116 allows withdrawal of gaseous oxygen from the container 104 . The gaseous withdrawal conduit 116 enters the container 104 and has a first outlet 117 communicating with an interior of the container 104 . The first outlet 117 is located adjacent a first juncture between the top portion 105 and the first side portion 108 of the container 104 .
The gaseous withdrawal conduit 116 exits both the container 104 and the outer shell 101 , and forms a first port 440 in the container 104 and in the outer shell 101 (see FIG. 4 ). The first port 440 is located adjacent the first juncture between the top portion 105 and the first side portion 108 of the container 104 .
The liquid withdrawal conduit 113 allows withdrawal of LOX from the container 104 . The liquid withdrawal conduit 113 extends diagonally across the interior of the container 104 and has a liquid withdrawal (second) outlet 114 positioned in the bottom portion 106 of the container 104 . The second outlet 114 is located adjacent a second juncture between the bottom portion 106 and the second side portion 109 . The liquid withdrawal conduit 113 may exit through a second port 441 adjacent the first port 440 , with the second port 441 preferably being concentric with the gaseous withdrawal conduit 116 and exiting within the first port 440 . Thus, at least a portion of the liquid withdrawal conduit 113 may be located within the gaseous withdrawal conduit 116 .
FIG. 2 shows an alternate position of the portable LOX unit 100 illustrating how the portable LOX unit 100 may be used in different orientations. As can be seen from the figure, the second outlet 114 of the liquid withdrawal conduit 113 still resides at a low point of the container 104 . It can also be seen from the figure that the first outlet 117 of the gaseous withdrawal conduit 116 remains at a high point in the portable LOX unit 100 . Even in a horizontal orientation, the portable LOX unit 100 maintains the liquid withdrawal conduit 113 and the gaseous withdrawal conduit 116 at desired positions to enable both LOX and gaseous oxygen withdrawal. Therefore, the position of the portable LOX unit 100 is not limited by the internal configuration of withdrawal conduits.
FIG. 3 shows a detail of the insulated support system 119 . The insulated support system 119 supports and positions the container 104 within the outer shell 101 (see FIGS. 1 and 2 ). A top insulated support 118 is centrally located on the top portion 105 of the container 104 and extends upwardly from the top portion 105 . A bottom insulated support 119 is centrally located on the bottom portion 106 of the container 104 and extends downwardly from the bottom portion 106 .
The insulated support system 119 includes an outer shell support 121 , a container support 124 , and an insulated support 127 . The outer shell support 121 is attached to the outer shell 101 (top or bottom), while the container support 124 is attached to the container 104 . The insulated support 127 is attached to neither and is merely placed between the two for the purposes of cushioning and insulating. Therefore, the container supports 124 of both the top and bottom insulated support systems 118 and 119 are telescopically received by the respective outer shell supports 121 .
It should be noted that the insulated support 127 is preferably made of an insulating material. This is done to minimize heat transfer from the outer shell 101 to the container 104 . Due to the insulated support 127 , the container support 124 does not come into contact with the outer shell support 121 .
FIG. 4 shows the portable LOX unit 100 of the present invention being used in a portable LOX system 400 . The portable LOX unit 100 further includes a third port 401 and a LOX delivery conduit 402 . The LOX delivery conduit 402 enters the outer shell 101 through a third port 401 and also enters the container 104 . The third port 401 is located adjacent a third juncture between the first side portion 108 and the bottom portion 106 (see FIG. 1 ). The LOX delivery conduit 402 terminates with an open end 404 located within the container 104 and adjacent the top portion 105 of the container 104 . Preferably, the open end 404 is centrally located within the top portion 105 , so that when LOX is being charged into the container, it flows along the internal sidewall portions of the container so as to minimize turbulence of LOX within the container, thereby facilitating maximal filling of the container with LOX.
Also shown in FIG. 4 is the emergence of the gaseous withdrawal conduit 116 and the liquid withdrawal conduit 113 from the portable LOX unit 100 . In this embodiment, both conduits 113 and 116 concentrically emerge from the container 104 , and then emerge from the outer shell 101 at the first port 440 .
While the invention has been described in detail above and shown in the drawings, the invention is not intended to be limited to the specific embodiments as described and shown.
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A portable liquid oxygen (LOX) storage/delivery apparatus is provided, including an insulated (LOX) container having an interior, a top portion, a bottom portion and a sidewall, the sidewall including a first side portion and a second side portion, both extending between the top portion of the bottom portion, and a port system in communication with the interior of the container for charging the container and for withdrawing LOX and gaseous oxygen from the container.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to fasteners for albums such as photographic albums and scrapbooks where it is the required to add or replace album pages.
[0003] 2. Description of the Prior Art
[0004] Certain types of photographic albums and scrapbooks are designed for easy expansion by the insertion of additional pages and pages may also be removable from the album as required. Conventially, such an album consists of separate front and rear covers and separate album pages between the covers. The album is held an assembled state by releasable fasteners, each consisting of a male and female screw inserted from the front and the back of the album, the female screw consisting of a screw head and an internally threaded shack and the male screw consisting of a head and an externally threaded shank, which engages within the internally threaded shank of the female screw. The two screws, when assembled, provide a fastening of variable length which can be adjusted within predetermined limits to suit the number of pages within the album. To permit replacement or insertion of pages, one or other of the screws is removed to permit removal of the front or the back cover and possibly some of the album pages at the front or back while the other screw remains in position to retain the remainder of the album pages in alignment. This screw-type fastening system has been in use for many years but is not particularly convenient to use as it can be quite difficult to align the male and female screws while maintaining alignment of the pages particularly when adding album sheets to increase the size of the album.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a releasable fastener for an album comprising front and back covers and removable pages between the covers, the fastener having a pair of strap anchors, one adapted to be attached to the front cover and the other to the back cover, a strap adapted to pass through aligned apertures in the covers and album pages from the strap anchor at the front to the strap anchor at the back, and means for providing a releasable connection between the strap and each of the strap anchors to enable insertion and removal of pages at the front and back of the album, the releasable connection permitting adjustment of the effective length of the strap between the anchors to accommodate a variable thickness of the album.
[0006] In a particularly preferred form of the invention, each strap anchor is in the form of a channel in which the strap is a snap lock to be releasably locked therein against displacement. Preferably the strap is snap-locked into the channel by snapping engagement beneath locking lips at an open side of the channel facing the base of the channel, and the base of the channel and opposing surface of the strap have formations which are engaged to prevent longitudinal displacement of the strap within the channel when its in its engaged position beneath the lips. These inter-engaging formations on the base of the channel and surface of the strap may consist of closely-spaced lateral ribs which are preferably of saw-tooth profile in cross-section, although other types of formations which co-operate to prevent longitudinal displacement of the strap could alternatively be used.
[0007] Preferably there are two or more opposed pairs of locking lips arranged at spaced intervals along the channel. This provides a more positive locking system than the incorporation of a single, long, locking lip extending along each edge of the channel at the open side thereof.
[0008] Preferably the strap enters into the channel via an aperture in the base of the channel and that aperture is bordered by a projection adapted to extend into the adjacent hole in the cover to ensure correct location between the strap anchor and the cover.
[0009] The present invention also provides an album having at least two fasteners as defined above mounted along the spine part of the album, the strap anchors of each fasteners being attached to the respective covers of the album.
[0010] In one practical form, the strap anchors can be adhesively attached to the respective covers, for example by double sided adhesive tape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:
[0012] FIG. 1 is a perspective view showing an album having fasteners in accordance with a preferred embodiment of the invention with the front cover of the album being shown in an open condition to expose the fasteners, each fastener having a pair of identical strap anchors and a strap extending between the anchor;
[0013] FIG. 2 is a plan view of the strap anchor of the fastener;
[0014] FIG. 3 is a transverse cross-section along line A-A of FIG. 2 and showing the pair of strap anchors of the fastener attached to the respective covers of the album, with the strap being omitted;
[0015] FIG. 4 is a cross-section similar to FIG. 3 but along line B-B of FIG. 2 to illustrate the form of the locking lips of the strap anchors;
[0016] FIG. 5 is a perspective view showing the end portion of the strap projecting into the anchor via an aperture in its base and prior to locking of the strap to the anchor;
[0017] FIG. 6 is a perspective view showing the strap when locked to the anchor;
[0018] FIGS. 7 and 8 are cross-sections corresponding to FIGS. 3 and 4 respectively but showing the strap locked within the anchors;
[0019] FIG. 9 is a longitudinal section through the spine of the album to show the pair of strap anchors and the strap locked thereto;
[0020] FIG. 10 is a longitudinal section similar to FIG. 9 and showing a modified embodiment;
[0021] FIG. 11 is a longitudinal section corresponding to FIG. 10 but with the strap omitted; and
[0022] FIG. 12 is a perspective view similar to FIG. 5 but showing the modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] An album fastener in accordance with a preferred embodiment of the invention comprises a strap 2 of variable length which passes through the album from the front to the back and a pair of identical strap anchors 4 mounted to external surfaces of the front and back covers 6 , 8 . Usually, the album will be assembled using a pair of such fasteners spaced along the spine of the album and that is what is shown in FIG. 1 . The strap 2 is of a semi-rigid plastics material formed on one surface with parallel ribs 10 which extend across the width of the strap 2 . Each strap anchor 4 is in the form of a channel having on its base a corresponding array of transverse ribs 12 to engage with those of the strap 2 when the strap 2 is pressed into the channel to thereby anchor the strap 2 against longitudinal movement within the channel. The exposed end portion of the strap 2 is a snap lock into the channel by being pushed into the channel from its open side facing the base, the strap 2 locking beneath pairs of opposed locking lips 14 at opposite sides of the channel. As shown there are two such pairs of lips 14 .
[0024] The strap 2 enters into the channel through an aperture 16 in the base of the channel adjacent one end and is then folded over and pressed into the channel to snap into engagement beneath the pairs of locking lips 14 which retain the ribs 10 in firm interlocking engagement with the ribs 12 at the base of the channel. The end of the strap 2 will project beyond the channel by a variable distance depending on the thickness of the album and can be easily be grasped to permit the strap to be disengaged from the channel by pulling the strap away from the base of the channel past the lips 14 . In the embodiment described, the snap action to effect the engagement occurs by resilient deflection of the locking lips 14 . In alternative forms however, this may be accompanied by resilient deflection also of the edge portions of the strap or even just the edge portions of the strap may resiliently deflect, with the locking lips being substantially rigid.
[0025] The cross-sectional profile of the strap 2 is designed to facilitate both its insertion into and its removal from the channel when required whilst also ensuring that a secure locking effect is provided. This cross-sectional profile is shown in FIGS. 7 and 8 from which it will be seen that each longitudinal edge of the strap is formed with an inner and outer pair of opposed chamfers 2 a, 2 b. The inner chamfers 2 a facilitate easy insertion into the channel and the outer chamfers 2 b facilitate easy removal from the channel when required, the pairs of locking lips 14 engaging the outer chamfers 2 b as clearly shown in FIG. 8 .
[0026] The strap anchors 4 are moulded in a suitable plastics material and can be attached to the front and back covers of the album by adhesive such as an adhesive tape, with the aperture 16 in the base of the channel being aligned with a hole in the adjacent cover 6 or 8 for passage of the strap 2 therethrough. Preferably, positive alignment is achieved between the aperture 16 and the hole in the adjacent cover by lugs 20 which project from the base of the channel at opposite sides of the aperture 16 to engage in the hole in the adjacent cover as shown in FIG. 9 . The material of the strap 2 is such that although it has sufficient flexibility to enable its projecting end to be bent into the channel and to be deflected past the lips 4 to be retained thereby it also has sufficient rigidity to enable it to be easily inserted through the aligned holes in the covers and album pages therebetween. Insertion of the strap through the holes will, due to the rigidity of the strap, tend to cause the holes in the successive pages to move into required alignment if they are slightly misaligned.
[0027] The opposed end portions of the strap 2 will be attached to the strap anchors 4 on the front and back covers in the manner described, and the strap 2 is of a length to permit adjustment of the album by incorporating additional sets of album pages as required. As a releasable strap anchor 4 provided on the front and back cover, either end of the strap can be released as required.
[0028] The insertion of the straps through the sheets when adding or replacing sheets is significantly easier than insertion of the two-part fastening screws conventionally used and the straps also provide significantly greater versatility in increasing the size of the album as the only controlling factor of the thickness of the album is the length of the strap and that can be made in a length which can accommodate substantial thickness variation.
[0029] Due to the relatively simple nature of the fasteners, they can be produced inexpensively so that their overall cost can be maintained at level comparable with that of the conventional fastening screws. This is quite important because albums of this type do attend to be quite cost-sensitive and despite the improvements obtained in the functionality of the fastener, the album still needs to be available at a price equivalent to that of albums with conventional screw-type fasteners.
[0030] It will be noted from FIG. 1 that the strap anchors 4 are actually applied to what is an inside surface of the cover. In the secured configuration of the fastener, an inner extension flap of the cover shown at 6 a in FIG. 1 is folded over to conceal the two strap anchors and straps. Only a small part of the front cover is actually shown in FIG. 1 and in FIG. 1 the front cover is depicted in its open condition; when closed, the main part of the front cover will be folded inwardly to overlie the extension 6 a. This configuration of front cover, which is repeated also for the back cover, corresponds to that which is used in albums using conventional screw-type fasteners. However, as a consequence of this cover arrangement in which the outer parts of the fastener lie inwardly of the cover when in its closed position, these outer parts do need to be of a low profile so that they do not interfere with closure of the cover. The simple channel form of the described strap anchors with the snap-lock of the straps therein permits the requisite low profile to be achieved as the channel itself is of low profile, and the strap is retained within the depth dimension of the channel by the locking lips without the need for additional locking means projecting outwardly from the channel.
[0031] In a modified embodiment of the invention as shown in FIGS. 10 to 12 the co-operating ribs 10 and 12 on the strap 2 and on the base of the channel 4 are of saw-tooth profile with the upright face of the profile orientated to prevent the strap 2 from being pulled through the channel 4 under the applied loading in the engaged condition of the strap. To ensure the required co-operation between the ribs 10 on the strap and the ribs 12 on the two identical strap anchors of the fastener, the orientation of the saw-tooth profile of the strap ribs is reversed midway along the length of the strap as is clearly shown in FIG. 10 .
[0032] In order to further improve the fixing of the strap in the channel to prevent slipping, additional ribs are also formed on the surface of the adjacent lug 20 and around which the strap passes when entering the aperture 16 . This is shown in FIG. 11 where the additional ribs are designated 12 a.
[0033] In this modified embodiment, in order to further improve the contact area between the ribs 10 and 12 , the ribs 12 have been extended in length to extend across the entire width of the channel 4 except in the zone of the lips 14 where they are of reduced width as a result of tooling considerations associated with the moulding of the lips. This is shown in FIG. 12 .
[0034] The embodiments have been described by way of example only, and modifications are possible within the scope of the invention.
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A releasable fastener for an album to permit insertion and removal of pages between the covers. The fastener has a pair of strap anchors each attached to one of the two covers and a strap passing between the anchors via aligned apertures in the covers and album pages. Each strap anchor is in the form of a channel in which the strap is a snap fit so that the strap is releasably locked into the channel and is restrained from longitudinal displacement by inter-engaging formations on the base of the channel and the opposing surface of the strap.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to a method for simultaneous extraction of essential oils and antioxidants from organic material, more particularly organic material from the Lamiaceae (or Labiatae) family, including rosemary ( Rosemarinus officinalis ) and, more specifically, to a method of simultaneous extraction of essential oils and antioxidants from species of the family Labiatae, in particular, rosemary, using solvent blends and which yields a liquid, oily extract containing antioxidants and a liquid extract containing essential oils. The extract containing antioxidants is readily mixed with an edible oil for addition to animal feeds and human food. The essential oils are pharmaceutical grade.
2. Background of the Prior Art
Worldwide demand for natural antioxidants has been rising due to safety concerns about synthetic food and feed additives and the public perception that natural food and feed supplements provide certain health benefits. The most important natural antioxidants being exploited commercially today are tocopherols. Tocopherols have a potent ability to inhibit lipid peroxidation in vivo by trapping peroxy-radicals (Burton, G. W., and K. U. Ingold (1989), in Vitamin E: Biochemistry and Health Implications, edited by A. T. Diplock, L. J. Machlin, L. Packer and W. A. Pryor, The New York Academy of Sciences, New York, pp. 7-22). Various herbal extracts for use as natural antioxidants are being explored. Possibilities include the extraction of rosemary or other botanical sources. Such new antioxidants may play a role in combating carcinogenesis as well as the aging process, and may be applicable in the nutraceutical industry.
Among the various natural extracts available in the market are rosemary extracts, which are reported to be highly effective in retarding lipid oxidation and protecting living cells from the damaging oxidative stress (Chen, Q., H. Shi and C-T Ho (1992), “Effects of rosemary extracts and major constituents on lipid oxidation and soybean lipoxygenase activity”, J Am Oil Chem Soc 69: 999-1002; Wong, J. W., K. Hashimoto and T. Shibamoto (1995), “Antioxidant activities of rosemary and sage extracts and vitamin E in a model meat system”, J Agric Food Chem 43: 2707-2712). These extracts are described as being superior to vitamin E, a well-known natural antioxidant and food supplement, in many food model systems (Lolinge, J. (1983), Natural antioxidants in Allen, J. C. and R. J. Hamilton eds, Rancidity in Foods, Elsevier Applied Science, London, Chapter 6). However, opposite findings are also documented. Wong et al. (1995) revealed that vitamin E is more effective than rosemary extract in a cooked beef homogenate. Additionally, rosemary extract is shown to be a synergist of vitamin E in stabilizing or retarding oxidation in sardine oil and fish muscle (Fang, X. and S. Wanda (1993), “Enhancing the antioxidant effect of α-tocopherol with rosemary extract in inhibiting catalyzed oxidation caused by Fe 2− and hemoprotein”, Food Res Int 26: 405-411; Wanda, S. and X. Fang (1992), “The synergistic antioxidant effect of rosemary extract and α-tocopherol in sardine oil model system and frozen-crushed fish meat”, J Food Process Preserv 16: 263-274).
As to the extraction of rosemary, many authors report that polar solvents yield extracts with higher antioxidant activities (Chang, S. S., B. Ostric-Matijasevic, C-L Huang and OA-L Hsieh (1977), “Natural antioxidants from rosemary and sage”, J Food Sci 42: 1102-1106). Chen et al. (1992) found that hexane extracts of rosemary contained a higher content of carnosic acid and carnosol than methanol extracts do. Carnosic acid and carnosol are the effective antioxidant molecules in rosemary. Carnosic acid and carnosol have been suggested to account for over 90% of the antioxidant activity of rosemary extracts (Aruoma, O. I, B. Halliwell, R. Aeschbach and J. Loligers (1992) “Antioxidant and pro-oxidant properties of active rosemary constituents: carnosol and carnosic acid”, Xenobiotica 22: 257-268). Antioxidant molecules in general, and rosemary antioxidants specifically, are by nature labile molecules especially when exposed to heat and/or air. During the harvest, the drying, and the regular solvent extraction of rosemary, some oxidation is likely to occur. Through a process of chemical reactions, carnosic acid, the naturally-occurring antioxidant molecule in rosemary, is believed to be the precursor to carnosol and many other antioxidants found therein (Wenkert, E., A. Fuchs, J. D. McChesney (1965), “Chemical artifacts from the family labiate”, J. Org. Chem. 30: 2931-2934). It can be demonstrated that the freshly cut leaves of rosemary do not contain carnosol (Aeschbach, R. and L. Philippossian (1993), “Carnosic acid obtention and uses”, U.S. Pat. No. 5,256,700). Carnosic acid is about 10 times more effective as an antioxidant than carnosol (Aruoma et al., 1992), and it, therefore, is important for the high activity of a rosemary extract to minimize the damage to carnosic acid.
Essential oils are volatile oils which are the aroma and flavor components of organic material. They are used in a variety of products such as incense, aromatherapy oils, perfumes, cosmetics, pharmaceuticals, beverages, and foods. The market for these oils demands consistent high quality and reliable supplies at competitive prices. Essential oils are typically commercially extracted from organic material such as rosemary using steam distillation. In this prior art process, the antioxidants are destroyed, and thermal degeneration of the essential oils may occur.
The antioxidant activity of commercially available rosemary products was compared with rosemary extracts prepared in the laboratory using various solvents for extraction. It was found that the antioxidant activity of commercial rosemary products was in the range of 2-5% when compared to mixed tocopherols. A methanol extract had 10% of the activity of mixed tocopherols. Methanol extraction, moreover, results in a dry powder that is difficult to dissolve into preferred carriers, such as edible oils. Accordingly, there were identified goals to increase the specific activity of extracts of species of the family Labiatae, including rosemary, by optimizing the solvent extraction methodology, to test alternate extraction technologies, and to improve the handling characteristics of the extract.
The investigation into alternate extraction technology had two primary objectives. Firstly, to increase the specific activity of the rosemary extracts further for more efficient formulation into soybean oil or other carrier; and, secondly, to identify technology allowing the removal of the essential oil fraction from the extracted material without oxidative destruction of the carnosic acid. One extraction technique investigated is based on tetrafluoroethane (TFE).
A process for the extraction of antioxidants and essential oils from rosemary preferably meets several criteria. It should be economical and also lead to a liquid or oil antioxidant extract that can be formulated into a homogeneous, soybean oil-based final product that is largely free of odor.
For the foregoing reasons, it is desired that a process be found that simultaneously yields antioxidants and essential oils suitable for further commercial use via a single solvent mix. The present invention solves this problem with sufficiently high yields and purities to be a commercially-viable process.
SUMMARY OF THE INVENTION
This invention is directed to a method of simultaneously extracting antioxidants and essential oils from organic materials and the extract products of the method.
A purpose of the invention is to identify a solvent blend and extraction parameters for the extraction of antioxidants of rosemary while attaining a high specific activity and retaining high extraction yields.
Another purpose of the present invention is to provide a method for extracting antioxidants from rosemary that yields a liquid, oily extract that is readily mixed with a liquid product, such as soybean oil, for incorporation into animal feeds and human foods.
A further purpose of the present invention is to provide a method for extracting essential oils from rosemary in high yields and high purity.
The organic material used during testing was dried, finely ground rosemary of the Arp variety. It is anticipated that the organic material can be any plant of the Labiatae family, and more broadly, any plant material which contains antioxidants and essential oils. It is also expected that any parts of the plant which contain the desired components may be extracted, as well as any form of the plant material (e.g., whole, ground, fresh, or dried).
Tetrafluoroethane was used in the solvent blend. Tetrafluoroethane has a boiling point of −27° C. The technology utilizes the vapor pressure of the solvent at room temperature and allows extraction under mild conditions, therefore minimizing the oxidative decomposition of carnosic acid during the extraction process. Tetrafluoroethane is substantially apolar and is preferably blended with acetone in the extractions of rosemary described here. The advantages of TFE show that it is non-flammable, has a low boiling point, is environmentally acceptable (very low toxicity), and is easily handled. It has been found that at ambient or sub-ambient temperatures, TFE leaves behind the majority of the waxes and other non-fragrant materials normally extracted with conventional solvents (Wilde P. F., 1994. Fragrance Extraction. European Patent No. 0616821A1). Another advantage with the use of TFE is that no distillation must be employed due to its low boiling point. It is anticipated that any hydrofluorocarbon (HFC) with a hydrocarbon backbone of three carbons or fewer (C1-C3) may be used, or mixtures thereof. Acetone and methanol were the organic solvents in the solvent blend. Though methanol alone extracts the antioxidants from rosemary very effectively, it leads to a dry powder extract and an inferior liquid final product after formulation into soybean oil. The optimum TFE-based solvent blend for the extraction of antioxidants from rosemary was identified and extraction parameters were defined. Among numerous solvent blends tested, an 80/15/5 weight percent blend of TFE/methanol/acetone, respectively, proved to be the most effective solvent resulting in a liquid extract with up to 35% of the tocopherol efficacy and an antioxidant yield of about 60% of the rosemary antioxidants. Mixtures of TFE and hexane or butane have been tested as well. Though hexane or butane works, they are not as efficient as acetone and methanol. It is anticipated that similar individual organic solvents added to the TFE may be used as well, or mixtures thereof. Examples include, but are not limited to, ethanol, ethylene chloride, isopropanol, methylene chloride, propylene glycol, and other food grade solvents. Yields may differ with different solvent mixtures, but any similar solvent mixture should simultaneously yield essential oils and antioxidants using the present process.
The organic material and solvent blend are added together in a 1:3 (organic material:solvent blend) or higher (i.e., 1:4, 1:5, etc.) weight ratio to perform the extraction step in any vessel which will be compatible with the components. Since the TFE is preferably added in liquid form, the vessel has to be a pressure vessel which will withstand pressures equal to those required to maintain the TFE in liquid form. The extraction has been carried out at ambient temperatures, but the pressure and temperature may be varied, so long as the TFE and organic solvents remain in liquid form. The extraction appears to be almost instantaneous when dried, finely ground rosemary is used, as there was no appreciable difference in efficacy of products and only small differences in yield whether the extraction is done for 5 minutes or 2 hours. The extraction has been carried out at greater than ambient temperature (up to approximately 40° C.) and found to increase yields (e.g., 7-8% crude extract at standard temperature and pressure and 17% crude extract at 40° C.) with a decline in efficacy of the products and a change in the physical characteristics of the final product due to what is believed to be an increased extraction of longer chain hydrocarbons.
The method for removing the organic material from the solution was filtration. Any suitable separation process known to one skilled in the art which does not interfere with the other steps of the method may be used.
The removal of the solvent blend has been accomplished by evaporation. Specifically, the removal has been in steps in order to remove the solvents selectively. The TFE may be removed by any suitable method known to one skilled in the art. A thin film evaporator is anticipated to be suitable for this process. The organic solvent(s) may be removed by any suitable method known to one skilled in the art as well. A wipe film evaporator is anticipated to be suitable for this process.
Once the TFE is removed, it may be cooled or the pressure increased until it reaches its liquid phase and recycled back for reuse. Removal of the organic solvent(s) in the wipe film evaporator yields the oily, liquid antioxidants. The organic solvent(s) may be further treated by any suitable process known to one skilled in the art, specifically column distillation, to separate the organic solvent(s) from the essential oils. The resulting essential oils are of very high purity (pharmaceutical grade) and surprisingly high yields (compared to previous extraction methods for obtaining essential oils).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a process diagram of the preferred embodiment of the extraction method of the present invention.
FIG. 2 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 1.
FIG. 3 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 1.
FIG. 4 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 1.
FIG. 5 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 1.
FIG. 6 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 1.
FIG. 7 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 2.
FIG. 8 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 3.
FIG. 9 is a chart of the antioxidant efficacy of a number of samples of rosemary extracted according to described Method 4.
FIG. 10 is a schematic diagram of extraction Method 1 of the present invention.
FIG. 11 is a schematic diagram of extraction Method 2 of the present invention.
FIG. 12 is a schematic diagram of extraction Method 3 of the present invention.
FIG. 13 is a schematic diagram of extraction Method 4 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the method of the present invention is shown in FIG. 1 . The process includes an extraction vessel 10 where the organic material 12 is extracted using the solvent blend at a pressure equal to that necessary to keep the TFE in liquid form and at ambient temperature. The solvent blend is premixed in a solvent blend tank 14 before being added to the extraction vessel 10 where the organic material 12 has been added. The solvents are added to the solvent blend tank 14 from fresh supply tanks, acetone tank 16 , methanol tank 18 , and TFE tank 20 , or alternatively, recycled from the end separation techniques.
After the desired natural organic components are extracted from the organic material 12 after a sufficient residence time, the mixture is passed through a filter 22 . The filtered extract then passes through a thin film evaporator 24 where the TFE is removed and the remaining extract passes to the next step. The removed TFE is recycled back through a cold-trap 26 to the TFE tank 20 for reuse.
The TFE-free extract then passes through a wipe film evaporator 28 where the liquid, oily antioxidant portion of the extract 30 is collected and the organic solvent portion of the extract is treated further. The organic solvent portion of the extract passes through column distillation 32 to separate the essential oils 34 from the organic solvents. The organic solvents are condensed in a cold-trap 26 before being recycled back to the solvent blend tank 14 .
The methods of this invention are further illustrated by the following experimental examples.
EXAMPLES
Example 1
The invention identifies methods of extracting rosemary with different TFE-based solvents and define preferred extraction conditions. A total of 17 different solvent blends, individually and combined, were used. Data presents the results of the analysis of extracts of rosemary produced from the Arp variety in terms of extraction yield (%) and percent efficacy when compared to 100% mixed tocopherols at equal applications of 500 ppm tested in chicken fat, and rosemary extract/tocopherols equivalency.
All samples were tested in untreated chicken fat at a treatment level of 500 ppm. These samples were then placed into an oxygen bomb pressurized to 50 psi with oxygen, placed in silicon oil at 100° C. and allowed to oxidize. All samples were compared against the induction time of fat treated with 250 ppm 100% mixed tocopherols at a calculated equal concentration level of 500 ppm.
In the data tables, the sample number, the solvent used, percent yield, percent efficacy of tocopherols, and equivalency of rosemary extract to grams of tocopherols are reported. The percent yield was calculated by dividing the yield of rosemary extract by the initial mass of rosemary and multiplication by 100%. The percent efficacy to tocopherols was calculated as follows:
IT sample ( 500 ppm ) - IT control 2 ( IT tocopherols250 ppm - IT control ) × 100 %
where “IT” is the induction time.
Tocopherol equivalent units (g) were calculated using the assumptions that 1.0 kg rosemary was extracted according to the individual methods, and the percent yield and percent efficacy are equivalent from the small scale to the large scale extraction process:
1000 g rosemary×(% yield/100%)×(% efficacy/100%)=tocopherol equivalent (g).
The poultry fat, used as a test matrix, was supplied from Tyson. The various rosemary accessions were obtained from the Chart Co., Papa Geno's Herb Garden, and the North Carolina Botanical Garden. All solvents were purchased from Fisher Scientific Co. The apparatus that the TFE/organic experiments were conducted in was purchased from the Advanced Phytonics facility in Cowfold Grange, Leeming, U.K. All rosemary leaves used in these experiments were from the Arp variety unless otherwise noted.
Method 1
Effect of Solvent Blends on Efficacy
For samples 1-17, 2.0 g of dried, ground rosemary leaves were introduced into a closed glass vial extractor. The sample was then extracted with 20 g tetrafluoroethane (TFE) or a TFE/solvent mix for two hours. At this time the filtrate was quantitatively transferred into a glass collection vial. The rosemary was then washed with 10.0 g of the extraction solution for five minutes. This liquid portion was added to the first filtrate collected. The rosemary was washed a second time with 10.0 g of the extracting solution and this was also added to the collection vial. After all of the filtrate solutions had been combined, the pressure in the vial was slowly released. After all of the TFE had evaporated, the other organic solution was removed under a stream of nitrogen gas under moderate heating. The extraction process is illustrated diagrammatically in FIG. 10 .
The purpose of this series of experiments ( FIG. 2 , samples 1-7) was to test the performance of various TFE/acetone blends for the extraction of antioxidants from rosemary. When used alone, TFE results in poor yield with low efficacy. Acetone was added in small amounts to the TFE, initially at a concentration of 5%. The efficacy of the extracts was increased dramatically, up to six-fold, when sample number 2 (95% TFE/5% acetone) was compared to the efficacy of the sample number 1 (100% TFE). As the concentration of the acetone was increased, yields increased steadily while the specific efficacy remained essentially the same after an initial steep increase. It appears that with increasing concentrations of acetone, the blend equally well extracts antioxidant components as well as non-antioxidant components. The yield data are presented in Table 1 and the antioxidant efficacy is illustrated in FIG. 2 .
TABLE 1
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
1
100% TFE
0.95
5.84
0.555
2
95% TFE/5% acetone
3.27
35.71
11.7
3
90% TFE/10% acetone
5.06
37.01
18.7
4
85% TFE/15% acetone
6.50
35.71
23.21
5
80% TFE/20% acetone
6.11
34.41
21.0
6
75% TFE/25% acetone
6.54
34.41
22.5
7
70% TFE/30% acetone
7.49
27.92
20.9
The purpose of the next set of experiments ( FIG. 3 , samples 1, 8-13) was to test the effect of varying the concentration of hexane when mixed with TFE. Generally, the effect of hexane added to TFE had a less pronounced effect on the performance when compared to the acetone results. However, as was observed with the acetone, hexane was also able to improve the efficacy of the extracts by five-fold when compared to sample number 1 (100% TFE). The yield data are presented in Table 2 and the antioxidant efficacy is illustrated in FIG. 3 .
TABLE 2
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
1
100% TFE
0.95
5.84
0.555
8
95% TFE/5% hexane
1.90
24.02
4.6
9
90% TFE/10% hexane
2.79
24.02
6.7
10
85% TFE/15% hexane
4.85
24.02
11.6
11
80% TFE/20% hexane
5.69
24.02
13.7
12
75% TFE/25% hexane
5.46
26.62
14.53
13
70% TFE/30% hexane
6.40
26.62
17.0
FIGS. 4 and 5 (samples 2-13) compare the two different groups of solvent systems in terms of yields and specific activity. A steady increase in extraction yields can be noted as the TFE is replaced by the two solvents hexane or acetone. As to the specific activity, a rapid increase followed by a long plateau is observed. On average the TFE/acetone extracts outperformed the TFE/hexane extracts by about 10% in terms of specific activity. However, at a concentration of 30% for both solvents, the extracts were approximately equal in efficacy.
Additional solvents and solvent mixes were tested in an attempt to increase the efficacy and the total antioxidant yield extracted from the rosemary. Table 5 and FIG. 6 (samples 1 and 14-17) display the results of these experiments. When a 90% TFE/10% butane blend was evaluated a three-fold increase in efficacy over sample number 1 (100% TFE) was observed. The TFE/butane extract was equal to a methanol extract. Next, several three-solvent blends were tested. The two solvents mixed with TFE were methanol and acetone, varying in concentration from 5 to 15 percent (see Table 4). Using a solvent mix of 80% TFE/15% MeOH/5% acetone, the extract obtained displayed the highest total yield with a specific efficacy of 29.22% of that of tocopherol and an extraction yield of 10.05%. Methanol in combination with acetone seems to augment extraction yields while maintaining high specific efficacy. The yield data are presented in Table 3 and the antioxidant efficacy is illustrated in FIG. 6 .
TABLE 3
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
1
100% TFE
0.95
5.84
0.555
14
90% TFE/10% butane
NA
20.12
—
15
80% TFE/5% MeOH/
7.85
30.52
23.9
15% acetone
16
80% TFE/10% MeOH/
6.34
34.42
21.8
10% acetone
17
80% TFE/15% MeOH/
10.05
29.22
29.4
5% acetone
Method 2
Effect of Multiple Extractions on Efficacy and Yield
For sample 18, 2.0 g of dried ground rosemary leaves were introduced into the glass-extracting vial. The sample was then extracted with 20.0 g of 85% TFE/15% acetone for two hours. This was repeated once more. At this time 40.0 g of the solvent mix was added to the extraction vial containing the rosemary. This was allowed to stand for 20 hours. The solvent was then removed and added to the previous two extracts. The TFE was then allowed to evaporate off and the acetone was removed under a stream of nitrogen gas with slight heat. The process is illustrated diagrammatically in FIG. 11 .
The possibility of attaining higher yields with repeated extractions while retaining the high efficacy of the extracts was explored. FIG. 7 represents the antioxidant activity of sample 18. Sample 18 was produced from the repeated extraction of rosemary over a 24-hour period using 85% TFE/15% acetone. No appreciable increase in the yield or decrease in efficacy was observed when compared to a single extraction. Table 4 presents the yield data.
TABLE 4
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
18
85% TFE/15% acetone
6.70
33.12
22.2
Method 3
Effect of Extracting a Methanol Extract of Rosemary with a TFE Blend
Sample 19 was prepared by taking 100.0 g of Arp rosemary leaves and extracting it with 600 ml of methanol for 48 hours. This was then filtered and the methanol was evaporated via vacuum rotary evaporator at 40° C. Samples 20 and 22 were prepared by taking 1.0 g of sample 19 and putting it into a glass-extracting vial. For sample 20, 10 g of 85% TFE/15% acetone was added to the 1.0 g of sample 19. This solution was allowed to extract the 1.0 g sample for two hours. This solution was then filtered away from the sample. This was repeated once more. Both solutions were then combined, the TFE was allowed to boil off, and the acetone was removed under a stream of nitrogen gas with slight heat. For sample 22, the same method was followed to prepare sample 20, however, instead of using 85% TFE/15% acetone as the extracting solvent, 70% TFE/30% hexane was used. The material (bagasse) that was left over from the process of preparing samples 20 and 22 was labeled 21 and 23, respectively. This process is illustrated schematically in FIG. 12 .
The possibility of utilizing the TFE based extraction process to further deodorize and purify a methanol extract of rosemary was explored (see FIG. 8 ). Methanol extracts possess close to 100% of the antioxidants from rosemary. With this in mind, TFE mixed with an organic solvent (acetone or hexane) may separate out or extract a larger majority of the antioxidants from a methanol extract over dried, ground rosemary leaves. The test was performed with both, acetone and hexane. Initial tests indicated that the TFE blend solvent extracts were approximately equal to the methanol extracts of dried, ground rosemary. The non-extracted portion, the bagasse, left over from the TFE based extraction (samples 21 and 23), retained a large amount of the antioxidant activity which had 13.64% and 12.34%, respectively, of the tocopherol activity. This residual efficacy indicated the lack of ability of the TFE/organic solvent mix to extract 100% of the antioxidants from a methanol extract of rosemary. Table 5 presents the yield data and FIG. 8 displays the antioxidant efficacy.
TABLE 5
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
19
100% methanol
27.66
20.13
36.0
20
85% TFE/15% acetone
3.91
38.31
15.0
21
Residue
NA
13.64
—
22
70% TFE/30% hexane
6.06
33.12
20.1
23
Residue
NA
12.34
—
Method 4
Extraction of Rosemary with 90% TFE/10% Acetone followed by Extraction of the Bagasse with Methanol
Sample 24 was prepared by taking 15.0 g of ground rosemary and placing it into a 250 ml-extracting vial. To this was added 100.0 g of a 90% TFE/10% acetone solvent mixture. This was allowed to stand for two hours and then the solvent was filtered away. The TFE was allowed to boil away and the acetone was removed under a stream of nitrogen gas with slight heat. The remaining bagasse was used to create sample 25. Sample 25 was prepared in the following way. Firstly, the remaining unextracted rosemary left over from the preparation of sample 24 was put into a 250 ml flask and 60 ml of methanol was added. This was allowed to extract for 48 hours. At this point, the solution was filtered and the methanol was removed via vacuum rotary evaporator at 40° C. This process is illustrated diagrammatically in FIG. 13 .
Whether any residual antioxidants are left after an extraction with a TFE blend was investigated (see FIG. 9 ). A sample of rosemary was extracted with a 90% TFE/10% acetone (sample 24) mix and the residual rosemary material was extracted with methanol (sample 25). The results indicated that a blend of TFE/10% acetone extracted approximately 30% of the antioxidants in rosemary. It appears that the presence of methanol in the solvent blend for the extraction of rosemary is critical for economical yields. The yield data are presented in Table 6 and the antioxidant efficacy displayed in FIG. 9 .
TABLE 6
Tocopherol
% Efficacy
Equivalent
No.
Solvent
% Yield
to Tocopherols
Units (g)
24
90% TFE/10% acetone
4.00
31.82
12.7
25
100% methanol
23.7
12.34
29.24
Example 2
Essential Oils Analysis
A sample of 1.8 kg of dried, finely ground rosemary was extracted for 1 hour at a temperature of 25-26° C. at a pressure of 7 bar using 18 kg of a solvent blend of 80% TFE, 12% methanol, and 8% acetone. After removal of the TFE, the extract was subjected to distillation to pull off the acetone and methanol. Analysis of the distillate by gas chromatography followed by mass spectroscopy showed the presence of the essential oils α-pinene, camphene, β-pinene, β-myrcene, eucalyptol, camphor, and caryophyllene.
Although the invention has been described with respect to a preferred embodiment thereof, it is to be also understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims.
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An increase in specific antioxidant activity of extracts from rosemary ( Rosemarinus officinalis ) is obtained by the use of a blend of tetrafluoroethane and acetone in the extraction process. A blend of tetrafluoroethane, acetone and methanol improves total yield. A tetrafluoroethane and acetone blend has higher efficacy but comparatively lower yields. The methods yield a liquid and oily antioxidant extract that is readily mixed with a liquid product such as soybean oil for addition to animal feeds and human food. The methods simultaneously yield pharmaceutical grade essential oils in high yields.
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FIELD OF THE INVENTION
The invention relates to an active sound damper for compensating interference noise radiated by an interference noise source.
BACKGROUND OF THE INVENTION
Sound dampers of the above kind are used in sound damping systems and reduce the sound level of a sound field, experienced as annoying. The overall sound damping system in principle has a sound damper as well as a sensor for providing information about the interference noise to be expected and/or a control sensor for receiving the already damped or canceled-out interference noise. The sensor signal corresponding to the noise level is supplied to a control unit for further processing. The processed sensor signal thereafter reaches a speaker in the form of an electrical signal. The speaker is a component of the sound damper and radiates compensation sound or (anti-sound), The electrical signal supplied to the speaker is calculated so that the two sound fields corresponding to the compensation sound and the interference noise overlap in antiphase according to the principle of interference known from physics. As a result, the interference noise is cancelled out or at least considerably reduced.
WO 91/15666 and U.S. Pat. No. 5,097,923 disclose active noise dampers for reducing exhaust noise in motor vehicles which have one or a plurality of speakers. Each speaker is disposed in a compensation sound chamber. Compensation sound chambers are disposed diametrically opposite one another on the pipe jacket of the exhaust pipe so that the radiation direction of the speaker runs radially to the exhaust pipe. Due to the lateral disposition of the speakers, the compensation sound waves must travel a certain distance to the pipe opening, which constitutes the radiation opening of the noise, in order to generate a homogeneous compensation sound field at that location. To this end, the compensation sound field generated in the sound chamber is supplied to the exhaust opening via a conduit disposed concentrically around the exhaust pipe. As a result, the sound damper takes up a great deal of space and has a structurally complex design. Due to the complex outer contour of the sound dampers of the prior art, their manufacture is difficult from a technical manufacturing viewpoint, and can consequently be very cost intensive.
Moreover, since installation conditions according to the prior art are often very cramped, and since the sound damper should therefore take up as little installation space as possible, a further volume enlargement of the sound damper, which already takes up a great deal of space, is possible, if at all, only in a limited manner. However, it is desirable to provide as large as possible a chamber particularly at the back end of the speaker in order to produce low-frequency tuning of the speaker. Therefore since, as pointed out above, it is impractical to provide more space for sound dampers of the prior art the efficiency of the speaker in prior art sound dampers is low. Furthermore, the exact coupling between the control sensor and the speaker is impeded due to the large transmission path between the speaker and the radiation opening of the exhaust pipe. The damping of interference noise according to the prior art is therefore insufficient.
An active sound damping system is known from EP-A-227 372, in which the radiation directions of interference noise and compensation sound are aligned approximately parallel to one another. However, the particular disposition of the speaker which generates the compensation sound requires a sound damper, which is structurally very complex and takes up a great deal of space, in order to be able to damp the noise.
The object of the invention is to embody a sound damper of the above mentioned kind in a space saving manner, and to produce an antiphase overlapping of interference noise and compensation sound in a geometrically simple manner.
SUMMARY OF THE INVENTION
The above object is attained by the invention, according to which, the speaker cone radially surrounds the radiation opening. As a result, the radiation directions of the compensation sound and the interference noise are aligned parallel to each other from the start and the acoustic centers of both sound fields are disposed on a common axis. Thus, according to the invention, transmission paths are completely unnecessary for the generation of a homogeneous compensation sound field for overlapping with the noise field. In this manner, an advantageous overlapping of noise and compensation sound is possible in a geometrically simple manner. Consequently, the sound damper is considerably simplified structurally. Due to the omitted transmission paths and the concentric disposition of the speaker, the sound damper is designed in a space-saving manner. The space thus saved can be used as the rear chamber of the speaker for the low-frequency tuning therefore. As a result, the sound damper according to the invention can be used even if space conditions are cramped.
The omitted transmission path between speaker and radiation opening makes possible a simplified transmitting function, and, consequently, a more precise coupling between the speaker and a control sensor which receives the damped interference noise. Since transmission delays are considerably reduced with the coupling, the speaker reacts rapidly and precisely to the changing interference noise level. The coupling, for example by means of a control unit, can as a result be realized by technically simpler means. The sound damper is by and large less costly to manufacture while at the same time having an increased efficiency.
Due to the short path difference between the speaker and the radiation opening, annoying resonances are produced only at high frequencies, which are not a concern in the use of the sound damper. As a result, the operation of the sound damper is more uniform over the entire relevant frequency range.
Normally, the speaker cone is embodied rotationally symmetrically with respect to the longitudinal axis of the speaker. It therefore has a circular cross section. Diverging from the above, the speaker cone can also have an elliptical cross sectional shape for example. Additionally, since the wavelengths applicable in the use of the sound damper are long relative the lateral dimensions of the speaker, a smooth compensation sound field is produced. With different cross sectional shapes of the speaker cone, the sound damper can be adapted even better to different space conditions.
Even a large speaker cone saves space due to the compact disposition of the speaker around the radiation opening. Therefore, the cone area can be selected to be large in many instances of use of the sound damper. In this manner, the large volume flow which is required for high compensation sound levels is produced by means of smaller oscillation amplitudes of the speaker cone. As a result, while the compensation effect of the speaker remains the same, the mechanical load on the speaker cone is further reduced. Therefore, the reliable operating method of the speaker is assured over an even larger period of time.
Different drive principles and structures of the speaker cone can be chosen for the speaker to be used.
According to one embodiment of the invention, the speaker operates according to the known electrodynamic drive principle. Electrodynamic speakers more than adequately meet the demand for quicker adjustability and adaptation to changing noise levels.
A speaker known for example from F. Hausdorf, Handbuch der Lautsprechertechnik (Handbook of Speaker Technology), Vol. 3, 1990, Copyright VISATON, p. 21 et seq., in a simple manner, has a conical construction which makes possible its disposition approximately concentric to the center of the radiation opening which radiates the interference noise.
According to another embodiment of the invention, the speaker cone and the radiation opening end approximately flush in the axial direction of the speaker. As a result, it is assured that the total compensation sound field generated by the speaker cone is used to cancel out the noise field. The speaker cone is configured as a funnel or as a flat cone for example.
According to yet another embodiment of the invention, the radiation opening is the pipe opening of a sound pipe. Therefore the sound damper according to the invention can also be used in internal combustion engines.
According to a further embodiment of the invention, the magnetic system, which is in general commonly known in connection with electrodynamic speakers, includes a central bore extending in the direction of the longitudinal axis of the speaker so that the sound pipe can pass through this bore. In the above manner, the sound pipe is used not only for guiding the interference noise, but also as a mechanical aid for fixing the speaker, and consequently also the entire sound damper, in place. The concentric disposition of the speaker around the sound pipe therefore makes it possible to install the sound damper in a manner which is simple from a technical assembly viewpoint. In addition, the number of fastening means required for a mechanically firm seating of the speaker can be reduced.
It should be mentioned that the ring magnet radially surrounds the pierced pole core in a known manner to form the magnetic system. Therefore, the ring magnet does not need to be additionally mechanically processed to radially surround the sound pipe. It is also possible, however, to interchange the pole core and the ring magnet. In this case, a ring-shaped pole core surrounds a pierced magnet core.
According to another embodiment of the invention, a radial spacing may be provided between the speaker and the sound pipe, which spacing acts as a closed intermediate space. The intermediate space is closed so that acoustic short circuits are prevented between the front and the back of the speaker. The radial spacing has the advantage that the speaker, in particular the magnetic system and the sensitive speaker cone, are not directly exposed to the effects of the sound pipe. This is important for example if the sound pipe is equipped as an exhaust pipe, which carries hot exhaust gases.
According to yet another embodiment of the invention, a heat insulation layer is provided for thermal insulation between the speaker and the sound pipe. With an appropriate layer thickness, the insulation layer can be disposed clamped between the sound pipe and the magnetic system so that no further fastening means are necessary for fastening the insulation layer on the pipe jacket of the sound pipe. It is furthermore advantageous if, in addition to the pipe jacket section in the region of the magnetic system, the insulation layer also covers the pipe jacket sections in the region of the speaker cone and in the region of the speaker back. As a result, the insulation layer produces a thermal insulation between the speaker and the entire sound pipe. The thermal insulation produces an action of the magnetic system which is independent of temperature fluctuations of the sound pipe so that the reliable operation of the speaker is assured.
According to a further embodiment of the invention, an intermediate pipe as an alternative insulating element. The intermediate pipe surrounds the sound pipe at a radial distance therefrom. The intermediate pipe functions as a cooling body and can absorb a large part of the heat radiated by the sound pipe.
According to a further measure for thermally insulating the speaker with respect to the sound pipe an insulating layer is provided, at least in the region of the magnetic system, in a pipe conduit defined between the intermediate pipe and the sound pipe.
According to a further possibility for thermally insulating the speaker or cooling the same, the coolant flowing through the pipe conduit between the sound pipe and the intermediate pipe can for example be air or a fluid.
According to one embodiment of the invention, the pipe conduit is closed in the axial direction at the front of the cone. As a result, it is assured that when the compensation sound field is formed, no additional bypass is produced, which could impede the required overlapping of the compensation sound field with the interference noise field. In addition, the closing produces a seal of the pipe conduit with regard to the front of the cone. As a result, an inadvertent escape of coolant at the front of the cone is reliably prevented.
According to another embodiment of the invention, the insulation layer has a double function as an insulation element between the speaker and the sound pipe and as a closing element for sealing the pipe conduit with regard to the front of the cone.
According to yet another embodiment of the invention, the intermediate pipe, which concentrically surrounds the sound pipe, has a further function. It is embodied structurally as a bass reflex tube. Bass reflex tubes are known from HiFi technology. In addition to having improved thermal insulation capabilities, an intermediary pipe of this kind considerably improves the efficiency of the speaker device in the low frequency range.
According to a further embodiment of the invention, cooling of the magnetic system of the speaker is provided. In order to effect the above, either the pole core, which radially surrounds the sound pipe, or in the case of the above-mentioned interchange of the pole core and the ring magnet, the magnet core, is pierced. A coolant, for example air or a fluid, flows through the central bore of the magnetic system. In order to be able to supply the cooling means to the magnetic system in the fashion of a circuit, and to withdraw the cooling means therefrom, the bore is connected to a hose line, for example. In an advantageous manner, the bores may be evenly distributed in the circumferential direction of the pole core or magnet core in order to effect an even cooling of the entire magnetic system. The bores are fluidically connected to one another as a component of a cooling circuit. This connection can be likewise produced for example by means of a hose line.
According to another embodiment of the invention, an acoustic baffle is provided to fulfill a double function. On the one hand, it supports the mechanically firm seating of the speaker inside the sound damper. For the above purpose, speaker is fastened with the frame edge of its speaker frame on the acoustic baffle. On the other hand, the acoustic baffle divides the front of the cone from the back of the cone in the axial direction of the speaker and prevents acoustic short circuits in a known manner.
The provision of a closed speaker housing according to a further embodiment of the invention completely prevents acoustic short circuits, even at the lowest frequencies. The compact arrangement of the speaker also makes possible the choice of a large chamber for the speaker housing on the back of the cone without impairing the space-saving design of the sound damper.
In a further embodiment, the chamber of the speaker housing can also contain the electronics required for the coupling between the sensors and the speaker. In the above case, the electronics are sufficiently electrically insulated and protected against mechanical damage without further technical means. Only one or a plurality of the sensors as well as their feed lines to the electronics are disposed outside the speaker housing as components of the sound damper. As a result, the entire sound damper constitutes a compact unit.
If the radiation opening is the pipe opening of a sound pipe, then, apart from the recess in the acoustic baffle for the insertion of the speaker, the speaker housing also contains a recess for lead-through of the sound pipe the recess providing a positive fit between the speaker housing and the sound pipe.
According to one embodiment of the invention, the sound damper is suited for sound damping in internal combustion engines of any type. The sound damper can also be used in ship building, for example.
According to another embodiment of the invention, the sound pipe is the exhaust pipe of a motor vehicle. The speaker housing is preferably composed of half shells, as is standard with mufflers in motor vehicle construction. In the above case, the outer shape of the half shells, which are made to fit the undercarriage of the vehicle, make possible an additionally enlarged chamber for the speaker housing. The half shell construction allows a manufacture of the speaker housing by means of all welding and folding technologies known from sound damper construction. Since these sound dampers are mass produced, the sound damper according to the invention can also be obtained for a reasonable price. In conventional sound damper construction, the half shells are stabilized by additional support bases. These support bases can be omitted when the conventional sound damper housing is used as the speaker housing. The speaker frame itself advantageously stabilizes the half shells. Therefore, the sound damper is constructed in a mechanically sturdy manner with a very low expenditure for parts. At the same time, the low number of components supports the assembly of the sound damper in an assembly-friendly manner. As a result, the sound damper according to the invention can be used as a reasonably priced sound damper in motor vehicles, the construction of which is considerably improved.
Annoying air resonances or standing waves can develop in the speaker housing. To damp the above the chamber of the speaker housing may be partially or completely with appropriate sound absorbing materials.
According to yet another embodiment of the invention, an acoustically transparent, perforated front attachment pipe may be provided, to better protect the speaker cone from the exhaust gases escaping from the pipe opening of an exhaust pipe. In the above arrangement, the front attachment pipe functions like an exhaust pipe which is elongated in the gas flow direction. Because of the acoustically transparent perforations of the front attachment pipe, the noise is further canceled out directly in front of the radiation opening. The exhaust gases, however, are carried away from the radiation opening in the gas flow direction inside the front attachment pipe. In the above manner, the speaker cone is exposed neither to very high exhaust gas temperatures nor to the harmful chemical compounds of the exhaust gases.
According to a further embodiment of the invention additionally, the speaker is well protected against mechanical damage on its cone front, for example against external pressure or impact forces by being fastened at the frame edge thereof to an acoustically transparent, perforated protective screen. The screen opening for the passage of the radiation opening can also be used as an aid in fixing the assembly of the protective screen in place on the sound damper.
Furthermore, the protective screen may be configured as a plate to take into account the space-saving construction of the sound damper.
In addition, a concentrating pipe disposed coaxially with respect to the radiation opening is effective for concentrating the zone for the overlapping of the noise and the compensating sound into a small volume in front of the radiation opening. The above arrangement ensures that as large as possible a percentage of the noise field is canceled out.
If the speaker is inserted in a speaker housing, the concentrating pipe can also be embodied as a one-piece elongation of the housing wall in the axial direction of the speaker. The concentrating pipe is then simply separated in the axial direction from the rest of the housing by the acoustic baffle and/or the speaker.
For providing a compact outer contour of the sound damper the perforated front attachment pipe and the concentrating pipe may be configured to end approximately flush with one another in the sound carrying direction. The front attachment pipe also protects the concentrating pipe from harmful exhaust gases.
According to one embodiment of the invention, an acoustically transparent, perforated protective screen may be fastened to the locking collar of the concentrating pipe. This protective screen protects the entire inner chamber enclosed by the concentrating pipe, including the speaker cone and, if need be the front attachment pipe, from mechanical damage. A screen opening is not required for the protective screen provided that the sound damper has no front attachment pipe. The protective screen attached to the concentrating pipe, in combination with the protective screen attached to the speaker, protects the speaker even more effectively against damage.
The sensor for receiving the compensated noise may be well protected against mechanical damage or other external influences without additional technical measures. In order to effect the above, at least one sensor for receiving the compensated interference noise is disposed inside the concentrating pipe. The sensor may be disposed at a radial distance with respect to the pipe axis extending in the axial direction of the concentrating pipe. The sensor can be fastened in a simple manner to the inner wall of the concentrating pipe. As a result, in addition to its concentrating function, the concentrating pipe also perform a mechanical protection and support function for the sensor.
Furthermore, a plurality of sensors, which are fastened to the concentrating pipe, can be provided for improved detection of the sound compensation. A sound damper, which is equipped with a plurality of sensors, can even be used if one sensor is defective. As a result, the repair-free service life of the sound damper is further lengthened with high efficiency. A plurality of sensors can be disposed in the circumferential direction of the concentrating pipe, for example with an even circumferential spacing.
The radial spacing of the sensor from the pipe axis of the concentrating pipe may be about 6/10 of the overall distance between the pipe axis and the inner wall of the concentrating pipe. As a result of this particular spacing with regard to the pipe axis, the sensor is insensitive to the first radial resonance of the two overlapped sound fields. A faulty detection of the sound compensation is consequently prevented.
According to one embodiment of the invention, an adapter hood, which functions as a pressure chamber, is mounted on the front of the cone. As a result, a pressure chamber speaker is produced, as is known from F. Hausdorf, Handbook of Speaker Technology, Handbuch der Lautsprechertechnik Vol. 3 1990, Copyright VISATON, p. 28 et seq. The adapter hood and the pipe section considerably improve the adaptation of the speaker cone to the air. Accordingly, the efficiency of the sound damper is increased in a simple manner. In a further function, the adapter hood and the pipe section protect the speaker and the radiation opening very efficiently against external mechanical influences.
The sound damper according to the invention is very compact and space-saving and is designed in a mechanically sturdy manner. Since the described components of the sound damper have a multiple function in many cases, the entire sound damper can be manufactured with a few components in a way that is both assembly-friendly and reasonable in price. Also a necessary exchange of individual components, for example in the event of a repair, is made considerably simpler.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects of the invention, together with other objects and advantages which may be attained by its use, will become more apparent upon reading the following detailed description of the invention taken in conjunction with the drawings. Shown in the drawings, where like reference numerals identify corresponding components, are in:
FIG. 1, a lateral view of the sound damper according to the invention, with a speaker in cross section,
FIG. 2, the sectional view of a conventional sound damper for exhaust systems in motor vehicles corresponding to the sectional line II--II in FIG. 3,
FIG. 3, the sectional view of the conventional sound damper corresponding to the sectional line III--III in FIG. 2,
FIG. 4, a sectional view of the sound damper according to the invention in exhaust systems in motor vehicles, corresponding to the sectional line IV--IV in FIG. 5,
FIG. 5, the sectional view of the sound damper corresponding to the sectional line V--V in FIG. 4,
FIG. 6 to
FIG. 13, the side view of the sound damper according to the invention in other embodiments.
DETAILED DESCRIPTION OF THE INVENTION
In the active sound damper 1 shown in FIG. 1, a speaker 2 is inserted into a closed speaker housing 3. The speaker 2 is embodied as a cone speaker.
A funnel-like, flared speaker cone 4, a speaker frame 5, which surrounds the speaker cone in a funnel-like manner, and a ring magnetic system are the essential components of the speaker 2. The magnetic system has pole plates 6, 7, a ring magnet 8, which is disposed between the pole plates 6,7, as well as a pole core 9, which is radially surrounded by the ring magnet 8. The structure and operation of the speaker 2 are generally knownand are described for example in F. Hausdorf, Handbuch der Lautsprechertechnik (Handbook of Speaker Technology), Vol. 3, 1990, Copyright VISATON, p. 22 et seq.
The pole plate 6 and the pole core 9 are centrally drilled in the axial direction 10 of the speaker 2. A dust protection cap, which is usually aligned to be perpendicular to the axial direction 10, is not provided in the region of the speaker cone 4. In this manner, the speaker 2 can concentrically surround a sound pipe 11. Thus, the pole core 9 rests directly against the pipe jacket of the sound pipe 11. The sound pipe 11 form-fittingly passes through a cutout 41 of the speaker housing 3 and is used to carry interference noise in the sound carrying direction 12. The interference noise is then radiated outward at the pipe opening of the sound pipe 11, which functions as a radiation opening 13. The speaker 2 isaligned relative to the sound pipe 11 in such a way that the radiation opening 13 and a frame edge 14, which defines the funnel opening of the speaker frame 5, are approximately disposed on the same level. As a result, conventionally standard transmission paths between the radiation opening 13 and a speaker are to a large extent prevented.
The frame edge 14 is fastened to an acoustic baffle 25, which constitutes acomponent of the speaker housing 3, by means of fastening means, not shown.
If sound pipe 11 is to conduct exhaust gases with correspondingly high exhaust gas temperatures are conducted therethrough, the pole core 9--as shown in FIG. 1--can be configured to contain a plurality of cooling bores15. The bores 15 are shown schematically. The bores 15 are in flow communication with one another, and with cooling lines 16, also shown schematically. As a result, a closed cooling circuit is produced, through which a suitable coolant for cooling the magnetic system flows. The cooling circuit is disposed either completely in the chamber 17 of the speaker housing 3, or disposed such that or the cooling lines 16 are led out of the speaker housing 3 at a suitable location.
FIGS. 2 and 3 show a conventional sound damper 18 for exhaust pipes 19 in motor vehicles, which is constructed in the semimonocoque design. The outer shape of the sound damper 18 is adapted to the undercarriage of the vehicle. The sound damper 18 is comprised of two half shells 20, 21, whichare sealingly connected to each other in an known manner by means of suitable connection techniques, e.g. welding. Support plates 22, 23 are aligned to be approximately perpendicular to the longitudinal axis of the exhaust pipe 19 in the chamber of the sound damper 18 to stabilize the chamber mechanically. Sound absorbing damping material is inserted in the chamber of the sound damper 18 to absorb sound.
The basic design of the sound damper 1 according to the invention can now be advantageously implemented this kind of conventional sound damper 18. For this purpose, the damping material 24 and the support plate 23 of FIGS. 2 and 3 may be replaced by the speaker shown in FIG. 1, which concentrically surrounds the exhaust pipe. In the above manner, an openingis produced in the half shells 20, 21 for incorporation of the speaker 2 which is effective for radiating compensation sound, as can be seen in FIGS. 4 and 5. In the course of the above, with its very sturdy speaker frame 5, the speaker 2, serving a double function produces on the one handthe required structural support for both shells 20, 21 for mechanically stabilizing the sound damper 18, and effects on the other hand the radiation of compensation sound for damping or canceling out the exhaust noise as noted above thus, the conventional, passive sound damper 18 may be converted into the active sound damper 1 according to the invention in a reasonably priced and technically simple manner. A cooling circuit, not shown in FIGS. 4 and 5, can likewise be provided for cooling the magnetic system of the speaker 2.
In FIG. 6, the frame edge 14 is fastened to an acoustic baffle 25, which includes a cutout approximately corresponding to the cross section of the frame edge 14 for the insertion of the speaker 2 in the axial direction 10. The sound baffle 25, the frame edge 14, and the radiation opening 13 are disposed approximately in the same plane. A chamber wall 26 respectively adjoins the acoustic baffle 25 on both sides of the speaker 2. The chamber walls 26 are only shown schematically and may be self-contained. The sound baffle 25 and the chamber walls 26 enclose a chamber which may contain interference noise. The chamber may for example be an engine room. A connection to the outside of the chamber permeable tointerference noise is produced via ventilation lines or the like. In this case, the sound pipe 11 is the ventilation line, having the radiation opening 13 as the ventilation opening to the outside. The interference noise issuing from a work- or engine room is canceled by means of the above described disposition of the speaker 2. In order to prevent acousticshort circuits, the back of the speaker 2 should be enclosed. A housing-like enclosure 42 is provided for the above purpose.
In FIG. 7, the sound pipe 11 is surrounded at a radial distance by an intermediate pipe 27 in the region of the speaker 2. The intermediate pipe27 extends in the axial direction 10 one end of pipe 27 extends beyond the pole plate 6 the other end of pipe 27 ends at the radiation opening 13. The pole core 9 rests directly against the pipe jacket of the intermediatepipe 27. The intermediate pipe 27 is comprised of a material, suitable for the thermal insulation of the speaker 2 with regard to the sound pipe 11. In addition, when its measurements are correspondingly dimensioned, the intermediate pipe 27 functions in the fashion of a bass reflex tube, and as a result, increases the efficiency of the sound damper 1 in canceling out interference noise.
In FIG. 8, the intermediate pipe 27 is disposed such that one of its ends extends outside the speaker housing 3 is opposite the radiation opening 13in the axial direction 10. In the above case, the pipe conduit 28 formed bythe radial distance between the sound pipe 11 and the intermediate pipe 27 is accessible from outside the speaker housing 3. Thus, a suitable coolant, such as air or a fluid for example, can be channeled into the pipe conduit 28 to cool the speaker 2. In addition, the pipe conduit 28 can be used as additional heat insulation between the sound pipe 11 and the speaker 2 by being filled with an insulating layer 29 in the region ofthe magnetic system of the speaker 2. In the region of the radiation opening 13, the pipe conduit 28 is closed in the axial direction 10 by another insulating layer 29. In another exemplary embodiment, not shown, the entire pipe conduit 28 inside the speaker housing 3 is filled with theinsulating layer 29.
The speaker housing 3 in FIG. 9 is filled with sound absorbing damping material 30 to prevent annoying resonances. In the above case, the dampingmaterial 30 covers the back wall of the speaker housing 3, which is disposed opposite the speaker cone 4 in the axial direction 10.
In FIG. 10, the sound pipe 11 is elongated in the sound carrying direction 12 at its radiation opening 13 by means of a front attachment pipe 31. Pipe 31 is manufactured either as a separate element attached to the radiation opening 13, or forms a one piece element together with the soundpipe 11. The interior diameter of the sound pipe 11 and of the front attachment pipe 31 are approximately the same. The pipe jacket of the front attachment pipe 31 contains a multitude of acoustically transparent perforations 32. With the aid of the front attachment pipe 31, exhaust gases flowing through the sound pipe 11 in the sound carrying direction 12are carried into a region remote from the speaker 2 and can only escape at the pipe opening of the front attachment pipe 31, which functions as the exhaust opening 33. As a result, the speaker 2 and in particular the sensitive speaker cone 4 are better protected from harmful exhaust gases. At the same time, the acoustically transparent perforations 32 assure the required overlapping of the interference noise field and the compensation sound field according to the exemplary embodiments of the sound damper 1 which do not include the front attachment pipe 31.
Furthermore, a concentrating pipe 34 is shown in FIG. 10. It adjoins the frame edge 14 on the front of the speaker cone 4 and extends in the axial direction 10. Viewed in the axial direction 10, the concentrating pipe 34 is flush with the speaker housing 3. The concentrating pipe 34 is either manufactured of one piece with the speaker housing 3 or is fastened as a separate element, for example to the frame edge 14. The concentrating pipe34 focuses the compensation sound waves radiated by the speaker cone 4. As a result, a concentrated overlap zone is produced in the region in front of the radiation opening 13 between the interference noise field and the compensation sound field. Therefore, a greater percentage of the compensation sound field generated by the speaker 2 is available for canceling out the interference noise. The efficiency of the sound damper 1is further improved as a result of the above arrangement.
In FIG. 11, the front of the speaker cone 4 is covered in the axial direction 10 by a plate-like, acoustically transparent, perforated protective screen 35. Screen 35 is represented schematically by a dashed line. The protective screen 35 is disposed approximately in the plane of the frame edge 14, and contains a central screen opening 36 for the radiation opening 13. The pipe end of the concentrating pipe 34 opposite the frame edge 14 in the axial direction 10 is connected to another protective screen 35'. Its screen opening 36' radially surrounds the exhaust opening 33 of the front attachment pipe 31. The protective screen 35' concentrating pipe 34 is used not only to protect the speaker 2 from mechanical damage, but also to protect two control sensors attached to theinner wall of the concentrating pipe 34. Each of the two control sensors isa microphone 37 which receives the canceled or damped interference noise and send a corresponding sensor signal to the control unit so that the speaker 2 is triggered depending upon the sensor signal. In other exemplary embodiments, other sensors or only a single sensor can be fastened to the inner wall of the concentrating pipe 34.
In another exemplary embodiment (not shown here), the microphone or microphones 37 are disposed at a radial distance with regard to a pipe axis 43 of the concentrating pipe 34, indicated by a dash-dotted line, which is 0.6 times the pipe radius 44 of the concentrating pipe 34.
In FIG. 12, the speaker 2 is covered in a hood-like manner on its front in the axial direction 10 by an attachment chamber 38. The attachment chamber38 is a dynamically balanced component having an imaginary axis of rotationwhich corresponds with the pipe axis of the sound pipe 11. Attachment chamber 38 is fixed with its edge areas to the frame edge 14 by fastening means, not shown here. Starting from the frame edge the attachment chamber38 has a cross section which tapers conically in the axial direction 10. The conical tapering terminates in a pipe section 39. The sound pipe 11 isextended in the sound carrying direction 12 beyond the plane of the frame edge 14 approximately to the pipe section 39. The latter defines a chamberopening 40 and surrounds the sound pipe 11 at a radial distance therefrom.
FIG. 13 shows a further exemplary embodiment of the attachment chamber 38. In the shown embodiment, attachment chamber 38 is configured as a plate thereby defining a plane which adjoins the plane of the frame edge 14 in aplane parallel manner. The plate-like attachment chamber 38 is bored at a center region thereof. The bore serves as a chamber opening 40. A pipe section 39 projects past the attachment chamber 38 in the axial direction 10. The pipe section 39 surrounds the sound pipe 11 and defines the chamber opening similar to the exemplary embodiment of the sound damper 1 according to FIG. 12.
The attachment chamber 38 and the pipe section 39 described above with respect to FIGS. 12 and 13 function in the fashion of a pressure chamber and as a result, transform the compensation sound radiated by the speaker 2 before it is overlayed with the interference noise in the region of the radiation opening 13. By means of the above transformation, the speaker cone 4 is better adapted to the air. The efficiency of the sound damper 1 is further improved.
The components shown and described in different embodiments of the sound damper 1 can naturally also be integrated into exemplary embodiments in which these components are not shown or described. Thus for example, the cooling circuit with the cooling lines 16 and bores 15, which is explainedby means of FIG. 1, is also suitable for the sound damper 1 according to the exemplary embodiments of FIGS. 4 to 13. In this sense, for example theconcentrating pipe 34 according to FIGS. 10 and 11 can naturally also be combined with the sound damper 1 according to the exemplary embodiments ofFIGS. 1 to 9.
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An active sound damper for compensating interference noise radiated by an interference noise source through a radiation opening of the interference source. The radiation opening of the interference noise source defines a radiation plane and has a center. The sound damper includes a speaker for radiating compensation sound for reciprocally effecting one of a weakening and a cancelling of the interference noise by interfering with the interference noise, the speaker having a speaker cone and defining a longitudinal axis. The speaker is further adapted to be mounted on the radiation opening such that its longitudinal axis is disposed to transversely intersect the radiation plane at the center of the radiation opening and such that the speaker cone radially surrounds the radiation opening.
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TECHNICAL FIELD
The present invention generally relates to motor vehicle remote keyless entry systems, and more particularly relates to secure motor vehicle remote keyless entry systems that prevent an unauthorized entity from accessing an encryption key.
BACKGROUND
Remote keyless entry systems are widely used in connection with motor vehicles. The owner of the motor vehicle or another authorized person can, for example, unlock one or more of the vehicle doors, lock the vehicle doors, unlock the vehicle trunk, or sound an alarm by pressing one of a plurality of buttons on a remote keyless entry device, often referred to as a key fob or remote keyless entry (RKE) transmitter. The key fob or RKE transmitter transmits a command signal, by some form of modulated electromagnetic radiation, to a receiver in the motor vehicle. The signal includes the command (e.g., unlock the driver door) and, at least, an identifier that identifies to the receiver that this particular RKE transmitter is authorized to send such a command to this particular motor vehicle. Although the RKE transmitter provides a great convenience to the vehicle owner, it also presents various security issues. In order to overcome these security issues, it is common to encrypt the transmission from the RKE transmitter to the receiver. Initial attempts at security used a fixed encryption key for the transmission. Unauthorized persons could monitor and record a transmission from the RKE transmitter and could use the recorded transmission to gain unauthorized access to the vehicle at some later time.
To improve security, motor vehicle manufacturers adopted a “rolling code” method of encryption. The rolling code is base on some type of transmitter specific “secret” that is shared between the transmitter and the receiver. That secret information is used as an encryption key, or as the key to a message authentication code (i.e., a code that can only be generated by one in possession of the key). Some input to the encryption/authentication process is incremented in a manner known to both the transmitter and the receiver with the transmission of each message. That is, each time a command is transmitted from the RKE transmitter to the receiver in the motor vehicle, some input is incremented to insure that the encrypted message or authenticator changes with each transmission. By using the rolling code, the system cannot be defeated by simply intercepting a transmission and repeating it later. There are many ways to implement rolling code encryption. In one form of the rolling code both the RKE transmitter and the receiver are set to an initial code seed and rolling algorithm. Every time a command message is sent from the RKE transmitter to the receiver, both the RKE transmitter and the receiver update the code according to the rolling algorithm. Because the receiver will not always receive a transmission from the RKE transmitter (a blind transmission), for example when the receiver is beyond the range of the RKE transmitter, the receiver must be able to look ahead and react to codes that are within an acceptable future code window. Some mechanism must be provided to resynchronize the RKE transmitter and the receiver if the transmitted code is not within the acceptable window. The need for resynchronization can occur, for example, when a lost RKE transmitter is replaced or when for any other reason the transmitted code is outside the window. Such need for resynchronization is met by placing the RKE transmitter and the receiver in a training or program mode. The necessity for providing for a training mode, however, creates an additional security issue. During the training, the RKE transmitter must transmit the code secret, such as an encryption key, to the receiver. An unauthorized person in possession of the RKE transmitter could place the RKE transmitter in the training mode and cause the RKE transmitter to transmit the secret information. The unauthorized person could record the secret information and use it to gain access to the motor vehicle at a later time. Although there are a multitude of methods for implementing a rolling code encryption method for a motor vehicle remote keyless entry system, all of those methods are susceptible to the security issues presented by the necessity for a training mode.
Accordingly, it is desirable to provide remote keyless entry devices, systems and methods that overcome the security issues attendant with prior devices, systems, and methods. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
BRIEF SUMMARY
A remote keyless entry device is provided for sending secure commands such as for locking and unlocking a motor vehicle. In accordance with one embodiment of the invention the remote keyless entry device comprises a key generating key, encryption means, and a transmitter. The key generating key is stored in and never transmitted from the remote keyless entry device. The encryption means uses the key generating key to generate a working key. The transmitter is configured to send a command encrypted with the working key.
A secure method is provided for sending an encrypted command from a remote keyless entry device to a receiver in a motor vehicle. A key generating key is defined within the remote keyless entry device, and that key generating key is used to generate a working key. The working key is transmitted from the remote keyless entry device to the receiver during a training session without transmitting the key generating key. After the training session, a message encrypted with the working key can be transmitted from the remote keyless entry device to the motor vehicle receiver. Decryption means within the receiver decrypt the transmitted message using the working key.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein
FIG. 1 schematically illustrates a secure remote keyless entry system 10 in accordance with one embodiment of the invention;
FIG. 2 schematically illustrates a working key generator in accordance with one embodiment of the invention; and
FIG. 3 illustrates, in flow chart format, a method for generating a working key in accordance with one embodiment of the invention.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
FIG. 1 schematically illustrates a secure remote keyless entry system 10 in accordance with one embodiment of the invention. System 10 includes a remote keyless entry device (RKE transmitter) 12 configured to transmit a secure command to a receiver 14 in a motor vehicle 16 .
RKE transmitter 12 includes, in accordance with the invention, a working key generator 17 for generating a working key for encrypting a command transmitted from the RKE transmitter to receiver 14 . As illustrated schematically in FIG. 2 , the working key generator includes a key generating key 18 that is RKE transmitter specific. That is, key generating key 18 is unique to a particular RKE transmitter. Key generating key 18 provides one input to encryption circuitry 20 . In accordance with one embodiment of the invention, an incrementable counter 22 provides a second input to encryption circuitry 20 . Preferably counter 22 is a non volatile counter. The encryption circuitry can be any circuit that implements an encryption algorithm such as a block encryption algorithm. Other encryption algorithms can also be employed. Although described as encryption circuitry, the function can be embodied in hardware or software in known manner. Regardless of how embodied, the functional embodiment will be referred to herein, without limitation, as a circuit. Similarly, counter 22 can be a circuit or software that incrementally generates numbers in known manner. Regardless of form, each of the sources of incremented numbers will be referred to herein, without limitation, as a counter, and more specifically as an incrementable counter. Encryption circuitry 20 combines key generating key 18 with the output of counter 22 to generate a working key 24 . As will be explained more fully below, a different working key is generated each time the remote keyless entry system is configured in the training mode. In the embodiment described above, different working keys are generated by incrementing counter 22 . A different working key is generated for each output of the incrementable counter. In accordance with one embodiment of the invention, the key generating key and the encryption circuitry together are configured as a pseudorandom number generator and the working key is a pseudorandom number. The pseudorandom number that is generated changes with each training session because the output of incrementable counter 22 is changed with each training session. Other mechanisms can be used to cause the pseudorandom number generator to generate a different pseudorandom number and hence a different working key each time a training session is enabled. In accordance with a further embodiment of the invention, the encryption circuitry and the key generating key are configured as a random number generator and the resulting working key is a random number. Again, as above, the random number that is generated changes with each training session because the output of incrementable counter 22 is changed with each training session. As those skilled in the art will appreciate, the generation of a random number is more difficult than the generation of a pseudorandom number, but provides a greater degree of security.
Referring again to FIG. 1 , the RKE transmitter also includes a transmitter 26 and an antenna 28 . Transmitter 26 can be, for example, a low power radio frequency (RF) transmitter. Transmitter 26 can also be an infrared (IR) transmitter or other form of transmitter capable of transmitting information by the modulation of electromagnetic radiation. Antenna 28 must be compatible with the form of transmitter selected. For example, if transmitter 26 is an IR transmitter, antenna 28 might be a lens or other optical device for steering the IR radiation. For ease of description, transmitter 26 will hereinafter be referred to, without limitation, as an RF transmitter. In accordance with one embodiment of the invention, RKE transmitter further includes a plurality of buttons 30 – 33 or other mechanisms for selecting a command to be transmitted to the motor vehicle. The commands with which the buttons are associated can be, for example, unlock the driver door, unlock all doors, lock all doors, unlock the trunk, and the like. Buttons 30 – 33 are coupled to provide input to a command assembler 36 within which the message that is to be transmitted is assembled. Command assembler 36 can be embodied in hardware or software. Also provided as an input to command assembler 36 is working key 24 generated by working key generator 17 . RKE transmitter 12 encrypts the command message assembled in command assembler 36 using working key 24 and any of the known rolling code encryption techniques. In accordance with one embodiment of the invention, a rolling code encryption can be accomplished as follows. The output of an incrementable counter 38 configured to provide an incremented number output is provided as a further input to the command assembler. Incrementable counter 38 can be similar to incrementable counter 22 described above. The output of counter 38 and the selected command are used to make up a plaintext message that is to be encrypted and then transmitted. The plaintext message is encrypted using the working key in an encryption algorithm 40 within command assembler 36 . Encryption algorithm 40 can be, for example, a block encryption algorithm or other know algorithm. Encryption algorithm 40 is preferably a nonlinear algorithm. A device identifier 42 such as a serial number may also be used as an input to the command assembler and as such becomes part of the plaintext message. Any part or all of the command message can be encrypted using encryption algorithm 40 . The encrypted message is coupled to transmitter 26 and is transmitted to receiver 14 .
Receiver 14 includes an antenna 44 coupled to an RF receiver 46 (or other type of receiver corresponding to the type of transmitter used in RKE transmitter 12 ) for receiving the encrypted command message from the RKE transmitter. In accordance with one embodiment of the invention, a two step reception process is carried out within receiver 14 . The two step process includes decryption and verification. First the working key is used to decrypt the received message to recover the plaintext and then the received message is verified. Coupled to receive the output of RF receiver 46 is decryption circuitry 48 . The decryption circuitry can be embodied in either hardware or software. Included in decryption circuitry 48 is a decryption algorithm 50 that reversed the encryption done by encryption algorithm 40 . Inputs to the decryption circuitry are the encrypted command message received by RF receiver 46 and working key 24 . The output of the encryption algorithm is used as one input to verification circuitry 51 . A second input to the verification circuitry is the output of an incrementable counter 52 that is synchronized with incrementable counter 38 . Incrementable counter 52 can be similar to incrementable counters 22 and 38 described above. The verification circuitry checks to see if the recovered counter value from the transmitted message is within an acceptable window defined by the value of the output of counter 52 plus some acceptable incremental count. If the counter outputs match, the received message is verified to be a valid message from a valid transmitter, and is outputted as a plaintext command message 53 corresponding to the plaintext message originally encrypted by encryption algorithm 40 . Command message 53 generates appropriate signals that are transmitted, for example by a local area network or by a wiring harness illustrated by numeral 54 , to door locks 56 , and the like.
The transmission of a message from the RKE transmitter to the motor vehicle can be accomplished by the following method, explained with continued reference to FIG. 1 . In accordance with one embodiment of the invention, the plaintext command message created in an RKE transmitter 12 is based on a command generated in response to input from the individual possessing the RKE transmitter and the output of an incrementable counter 38 . The individual possessing the RKE transmitter is usually the owner of the motor vehicle or other authorized user. The input from that individual is generated, for example, by pushing one of buttons 30 – 33 on the RKE transmitter. The plaintext command message may also include an identifier 42 identifying the particular RKE transmitter. Part or all of the command message is encrypted by an encryption algorithm 40 using a working key 24 . The output of the encryption algorithm, a ciphertext version of the command message, is transmitted by transmitter 26 to a receiver 14 in motor vehicle 16 . Each time a message is transmitted by transmitter 26 , incrementable counter 38 is incremented so that the next command message encrypted by the working key and transmitted by transmitter 26 will include a different incrementable counter output. That is, the encrypted message changes for each subsequent command message transmission. Upon receipt by receiver 14 of a cipher message transmitted by transmitter 26 , decryption circuitry 48 decrypts the message to retrieve the plaintext command message. The decryption circuitry is configured with decryption algorithm 50 to reverse the encryption process of encryption algorithm 40 and to recover the output of incrementable counter 38 which has been included in the transmitted message. Incrementable counter 52 is initially synchronized to incrementable counter 38 . Each time a message is received by receiver 14 , decrypted by decryption circuitry 48 , and verified as a valid message from a valid transmitter by verification circuitry 51 , incrementable counter 52 is resynchronized to the value of incrementable counter 38 that was received in the encrypted message. The inputs to decryption circuitry 48 are the working key 24 , and the ciphertext command message received by receiver 14 . The manner in which decryption algorithm 50 receives the correct working key is described below. By incrementing incrementable counter 38 each time a message is transmitted by transmitter 26 and by resynchronizing incrementable counter 52 each time a message is received by receiver 14 , decrypted by decryption circuitry 48 , and verified to be a valid message, the two incrementable counters 38 and 52 stay substantially synchronized. Because incrementable counter 38 may be incremented without a corresponding incrementing of incrementable counter 52 , for example by a blind transmission by transmitter 26 , verification circuitry 51 is configured to accept messages based upon the current output of incrementable counter 52 as well as a predetermined window of future counts. Each time a message is successfully verified by verification circuitry 51 , incrementable counters 38 and 52 are resynchronized.
The working key is used by and hence must be known by both the encryption circuitry and the decryption circuitry. The working key must be transmitted from the RKE transmitter to the receiver in the motor vehicle during a programming or training session. An effective remote keyless entry system must allow for multiple training sessions, for example to eliminate the need to replace transmitters if the receiver needs to be replaced. In prior art systems, the training process is a potential security issue. If an unauthorized individual gains temporary possession of the RKE transmitter (for example a valet at a valet parking facility), that individual might cause the RKE transmitter to go into its training mode and cause the prior art RKE transmitter to transmit its secret information including the encryption key. If this information was recorded by the unauthorized user, the information could be used at a later time to generate a valid keyless entry message to gain unauthorized access to the motor vehicle. The remote keyless entry system and method of the present invention overcome such a security issue while still allowing multiple training sessions.
The method for generating a working key in accordance with one embodiment of the invention is illustrated in flow chart format in FIG. 3 with continued reference to FIGS. 1 and 2 . A cryptographic process is used to generate a stream of secure pseudorandom numbers which are then used as the shared information, i.e., the working keys, for the secure remote keyless entry system. Working key generator 17 includes a key generating key 18 such as an n-bit number that is loaded at the time of assembly at the factory or that can be selected and installed by the owner. The key generating key is unique and specific to one particular RKE transmitter. The key generating key, in accordance with the invention, is never transmitted, even during a training session. Working key generator 17 also includes a non volatile incrementable counter 22 that is configured to generate a series of incremented numbers. The list of incremented numbers produced by the counter is sufficiently long to prevent an unauthorized possessor of the RKE transmitter from recycling the counter within a reasonable period of time. As illustrated in FIG. 3 , the process of training the transmitter and receiver in accordance with one embodiment of the invention begins at step 100 . The non volatile counter is incremented to output an incremented number (step 102 ), i.e., a number unique to this training session. The key generating key and the incremental number output from non volatile counter 22 are combined (step 104 ) in encryption circuitry 20 using the encryption algorithm embodied therein to produce a working key 24 . The output of the working key generator can be coupled directly to transmitter 26 for transmission (step 106 ) to receiver 14 . The receiver incorporates the working key into the decryption algorithm embodied in the decryption circuitry (step 108 ). The output of the working key generator, working key 24 , is also incorporated into encryption algorithm 40 in the RKE transmitter (step 110 ). The training session is then terminated (step 112 ). During the training session, only the working key is transmitted, not the key generating key. Each training process results in a new working key because the non volatile counter increments during each training session, outputting a new incremented number used in the generation of the new working key. Even if an unauthorized user has a complete description of the encryption algorithm, gains possession of the RKE transmitter, and is able to put it into the training mode, the information that can be gained will not provide access to the motor vehicle either currently (because the receiver would still be using the previous working key) or in the future (because any reprogramming undertaken by an authorized user would also result in the use of a different working key). The unauthorized user will be unable to generate either past or future keys because the ability to generate working keys depends on the key generating key which is kept secret and never transmitted.
Although not illustrated, the training session can also be used to synchronize incrementable counters 38 and 52 . Such synchronization can also be accomplished in other know methods.
In the foregoing, various elements have been described as “circuitry” and certain functions have been described as being implementable in either hardware or software. The various elements and functions can be implemented, for example, with a general purpose microcontroller unit (MCU) programmed in a known manner.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof. For example, only one method has been described for implementing a rolling code encryption system. The invention is equally applicable to other rolling code systems that use a shared secret between a transmitter and a receiver. Further, those of skill in the art will recognize that other encryption algorithms can be used in implementing the inventive system and method.
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Methods and apparatus are provided for sending an encrypted command message from a remote keyless entry device to a receiver in a motor vehicle. The method comprises defining a key generating key within the remote keyless entry device, and using that key generating key to generate a working key. The working key is transmitted from the remote keyless entry device to the receiver during a training session without transmitting the key generating key. The working key is modified each time the remote keyless entry device is placed in the training mode. After the training session, a message encrypted with the working key can be transmitted from the remote keyless entry device to the motor vehicle receiver where the encrypted message is decrypted with the working key.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a combined can opener for separating a lid from a can and for tear-opening a can.
2. Description of Prior Art
For years the applicant has successfully produced and marketed can openers for opening conventional cans. With many conventional systems the can lid is cut through along an inner edge and separated from a lateral wall of the can. Since the separated part of the lid is sharp-edged and may cause injury, in the last years so-called safety can openers have been introduced which cut through the can lid along an outer edge. The connection between the can wall and the lid is released without sharp edges remaining on the lid to be removed or on the can edge. Because the cutting wheel does not contact the can contents the cutting mechanics of the opener are not dirtied and the can contents are protected from contamination from the cutting mechanics.
Such safety can openers are for example known from U.S. Pat. No. 4,782,594 and German Patent Reference 298 02 030. For both cutting principles, pincer models as well as one-armed models are known.
In order to open cans without a can opener, the packaging industry offers cans wherein the lid is released, by a pull or tear-open ring, from the can along a peripheral break-off line. Such tear-open cans are more complicated to manufacture and thus more expensive than conventional cans. The break-off lines create tight manufacturing tolerances and are thus more susceptible to erroneous functions.
If for example a material thickness along the break-off line is too great, then opening requires the application of a considerable pulling force. Older or weaker persons opening such a can causes particular problems.
U.S. Pat. No. 5,018,409 discloses an opener for tear-open cans. On the front end of this opener on an upper side there is a recess which defines a lug for suspending the tear-open ring. The rear part of the flat opener is formed parabolically and blends into a narrower grip part. For opening a tear-open can, the ring attached on the lid at the edge is lifted up and at the same time the break-off line directly in front of the ring is broken through, in the known manner. Now the ring is suspended into the recess on the front end of the opener and by pressure on the grip part while exploiting the lever arm, the can lid is released from the can. The opener at the same time with its parabolic back is rolled over the can lid and simultaneously the lid region which carries the tear-open ring is lifted and pulled upwards and to the rear. The opener which, for example, may be punched from one piece of sheet metal is relatively narrow. The contact surface of the opener back on the can lid is therefore small and on account of this on opening a can of the opener may easily slip.
A further opener for tear-open cans is disclosed in the U.S. Design Pat. No. D 267,925. This opener is manufactured from a flat piece of sheet metal. It has a hook-like end for opening the tear-open can as well as an opposite end for opening bottles with crown tops. The very narrow opener can easily slip when being used.
If the two previously mentioned conventional openers are for opening larger cans then the conventional openers are designed correspondingly large, which makes them unwieldy and bulky.
Both of the previously mentioned conventional openers do not open conventional cans.
SUMMARY OF THE INVENTION
One object of this invention is to make available a space-saving can opener which permits all commercially available cans to be opened securely and comfortably and which does not have the previously mentioned disadvantages.
These objects are achieved by a device according to the features and embodiments described in the specification and in the claims.
The can opener according to this invention can open common types of can packagings otherwise opened with only a single apparatus and is ergonomic and has a functionally advantageous shape that offers comfort and safety. Furthermore, the opener according to this, invention can be stored in a space-saving manner.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings are embodiments of this invention which are explained in the subsequent description, wherein:
FIG. 1 is a side view of one embodiment of the opener according to this invention, with a folded out pull hook, wherein a body of the opener in a region of an attachment of the pull hook is shown in a partial cross section;
FIG. 2 is a top view of the can opener according to this invention, as shown in FIG. 1;
FIG. 3 is a side view of a further embodiment of the opener according to this invention, partly in cross section, with a folded-in pull hook, wherein the pull hook in a folded-out position is shown in phantom lines and the cutting mechanics are not shown;
FIG. 4 is a top view of the can opener according to this invention, as shown in FIG. 3, wherein the cutting mechanics are not shown; and
FIG. 5 is a side view of a pull hook according to this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The drawings show two embodiments of the subject matter of this invention, which essentially differ in the design of the pull hook and the adaptations connected to the pull hook. For functionally equal elements in the following specification, the same reference numerals are applied. A first embodiment form is shown in FIGS. 1 and 2, having the cutting mechanism 20 while FIGS. 3 to 5 show a second embodiment form) wherein the cutting mechanism is omitted.
The opener as a whole is indicated with element reference numeral 1 . This has, as an essential element, a grip-like body 10 . The grip-like body 10 has two parallel, planar side surfaces 11 as shown in the top view of FIG. 2 . The grip-like body 10 has an upper arcuate back surface 12 and an opposite lower curved surface 13 . The curved lower surface 13 at one end there forms a head 15 in which the cutting mechanism 20 is accommodated and at the other end a thickened grip end 16 in which the pull hook 30 at least partly is accommodated. Between the head 15 and the thickened grip piece 16 there is formed a grip trough 14 in the curved lower surface 13 . In the thickened grip end 16 centrally and parallel to the two side surfaces 11 there is a receiving groove 17 . The receiving groove 17 begins at the thickened grip end 16 and is directed inclined towards the grip trough 14 runs out into the curved lower surface 13 . The receiving groove 17 in the thickened grip end 16 forms two side cheeks which are transversely passed through by a pivoting axis bearing 18 .
In the thickened head 15 there is located the cutting mechanism indicated as a whole at 20 which comprises a traction wheel 21 seated on a traction pin 26 in a rotationally secure manner. The traction pin 26 runs perpendicular to the planar side surfaces 11 and completely passes through the grip-like body 10 . On that end of the traction pin 26 lying opposite the traction wheel 21 there is a rotary grip 22 by way of which the traction wheel 21 is actuated. Perpendicular to the traction pin 26 there runs a pin of the cutting wheel 23 . The cutting wheel 23 during the actuation of the cutting mechanism lies on an outside on the weld bulge of the tin or can to be opened and cuts through the tin or can. A two-point contact bow 24 also lies on the upper edge of the can bulge. The cutting wheel 23 with the two-point contact bow 24 encloses an acute angle in order to produce a separating force directed upwards. Such cutting mechanisms are known.
In the receiving groove 17 of the grip-like body 10 there is partly accommodated a pivotal pull hook 30 . The pull hook 30 is pivotable by a certain angle about a pivot pin 31 which passes through the pivot pin bearing 18 . In the pivoted-in position the pull hook 30 with its pull hook inner edge 35 bears on the groove base 17 ′. In the pivoted-out condition the rear-side end near the pivot pin 31 comes to bear on the groove base 17 ′ by which means the pivoting movement of the pull hook 30 is limited.
The pull hook 30 is a planar, relatively thick element. It can be formed of a steel plate or also of a high-strength, for example glass-fibre reinforced plastic. The pivot pin 31 , which as already mentioned lies in the pivot pin bearing 18 , passes through the pull hook 30 . The pull hook 30 in the embodiment according to FIG. 1 has a straight-running pull hook inner edge 35 and a convex rolling back 33 . At an end distant to the pivot pin 31 the pull hook 30 on the pull hook inner edge 35 comprises an attachment recess 32 . On actuation the pull ring R lies in the attachment recess 32 . The shape of the attachment recess 32 may be configured in any way but it must be formed so that the pull ring R during the actuation does not slip out of the attachment recess 32 . This, for example, is achieved by an approximately rectangular or trapezoidal recess.
The course of the pull hook inner edge 35 is not of a direct importance. Instead of the straight course shown here the inner edge 35 may be shaped curving inwards or outwards. If the inner edge 35 is curved inwards then the pull hook 30 has more of a crescent-shape configuration, by which the strength of the pull hook itself is reduced. If however the inner edge 35 of the pull hook 30 is curved outwards then correspondingly the receiving groove must be deepened, respectively the groove base 17 ′ be directed concavely inwards. This then accordingly leads to a reduction of the cross section of the grip-like body 10 in this region and accordingly to a certain weakening.
FIG. 5 shows an optimized form of the pull hook 30 . The attachment recess 32 is located roughly at the opposite end to the pivot pin 34 . In contrast to the embodiment form according to the FIGS. 1 and 2, the pull hook inner edge 35 is shown running straight and then slightly angled toward a pivot bow 37 which transitions into a contact edge 38 . The rolling back 33 is shaped roughly equal to that of the previously described solution. Near the attachment recess the rolling back 33 has a radius r 1 while in the region near the pivot pin bearing 34 the rolling back 33 has a radius r 2 . The radius r 1 is shown smaller than the radius r 2 and thus the pull ring R initially exerts a more upwardly directed pulling component. FIG. 1 schematically shows the opening operation in a dashed line. The pull ring R lies in the attachment recess 32 and the tear-open lid D is pulled upwards, while the pull hook 30 rolls on the not yet opened region of the lid of the tin B or can.
As already mentioned the pull hook 30 in the embodiment shown in FIG. 5 comprises the pull hook inner edge 35 running angled. With the angled location 36 the pivot pin bearing 34 is positioned practically above the extended pull hook inner edge 35 . This permits the formation of the contact edge 38 which bears on the base of an abutment recess 19 in the grip-like body. With this configuration an improved force transfer from the pull hook 30 into the grip-like body 10 takes place. Simultaneously, however the pull hook 30 is rather reinforced while the cross section of the grip-like body with the angled course of the groove base 17 ′ is slightly reduced and because at the same time the pivot axis 31 is practically arranged in the extension of the groove base 17 ′, the force via the abutment surface is directly introduced into the stiffened region. In the previously described embodiment, practically the entire force was introduced via the bearing into the mentioned side cheeks laterally of the receiving groove 17 .
In the FIGS. 3 and 4, the described cutting mechanism is not shown. In the grip-like body 10 preferably manufactured of plastic only the driving pin bearing 25 and the receiving bores 27 for the contact bow 24 are evident.
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An opener having a grip-like body in which at one end is integrated a cutting mechanism for cutting open tins. An oppositely-lying thickened end has a receiving groove in which a pull hook is pivotally mounted about a pivot pin over a predetermined angle. For opening tear-open lids, a pull-ring is captured within an attachment recess on a pull hook inner edge. When pivoting the grip-like body the pull hook rolls along a rolling back of the pull hook, on the can lid and pulls up.
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FIELD OF THE INVENTION
[0001] The present disclosure relates to a method of improving grinding in an alumina extraction process.
BACKGROUND
[0002] Alumina producers are constantly striving to make the process of extracting alumina from bauxite more economical; producers want to be able to make as much alumina as possible at the lowest operating cost. One aspect of an alumina extraction process that directly impacts process economics is the dynamics of the grinding stage.
[0003] The Bayer process is the most common process used to produce alumina (Al 2 O 3 ) from bauxite ore. In a typical Bayer plant grind circuit, the bauxite ore(s) are combined with recycled caustic liquor, to generate slurry containing 25 to 55% solids.
[0004] The comminution process used depends on the bauxite type and physical characteristics (e.g. mineral composition, particle size, hardness and toughness). In general, the bauxite slurry is wet ground in a mill or a combination of mills including a rod mill, ball mill or a hammer mill. Rod mills may be used first to break large and tougher sized particles down to between 5 to 2 mm in diameter. Various screen types may be located at the discharge of the rod mill or a separate down stream Trommel screen, may be used for specific sizing control. The oversized particles are then recycled back to the inlet of the rod mill, while the under size material continues toward the digestion area.
[0005] Again depending on the nature of the bauxite(s) used in the plant, the slurry may be ground further to meet specific particle size targets. This is generally done to ensure effective down stream de-silication (if needed) but ultimately for effective alumina extraction in the digestion section of the plant. Thus, following the rod mills, a series of screens or cyclones may be used to separate the slurry grind for further recycling and grinding or to remove the finest particles so these may be transferred directly to the slurry relay tank. Comminution of the remaining slurry is then effected in a ball mill to give bauxite particle sizes below 0.5 to 0.1 mm. Ideally, the ratio of bauxite to spent liquor, which is added at the grinding stage, is driven solely by the alumina content in the bauxite and the desired liquor productivity. If higher than acceptable viscosity of the ground slurry occurs, then the capacity of the grinding circuit can be limited in order to affect adequate grinding of the bauxite.
[0006] Several operating factors affect the throughput of bauxite in the circuit. These include the type and size of mill used, the specific media charge and the downstream sizing control used. Poor grinding efficiency may be caused by excess bauxite flow for the size of the mill, very high slurry viscosity, larger than desired initial bauxite sizes and or insufficient media charge. This can result in a higher amount of recycle in the mill and an increase in energy consumption. In some cases, two mills might be used where the initial design called for only one mill.
[0007] Furthermore, in open milling circuits where sizing control is limited, poor grinding efficiencies will lead to challenges in maintaining adequate suspension of the oversized particles in down stream storage tanks. This can lead to higher mixing demands in the slurry relay and desilication sections of the circuit. The remedy in such circuits is often to cut the throughput of the bauxite in the circuit and this can lower plant alumina production.
[0008] Over grinding of the bauxite can also occur from a number of factors, namely, lower than design flow rates, low bauxite solid charges, high media charges, or as a result of excessive recycling within the mill circuit, for example, due to excessive scaling in either the mill discharge screens, or in down stream sizing control operations. Over grinding wastes energy and increases the particle surface area and the bulk viscosity of the bauxite slurry. This can directly affect the down stream pumpability of the slurry. Furthermore, inherent for some bauxites, high slurry viscosity increases the “stickiness” of the slurry, which can negatively affect scaling rates on screens, and in vessels and agitators in the pre-desilication section.
[0009] Improvements in the efficiency of grinding in an alumina extraction process are addressed in this disclosure.
SUMMARY OF THE INVENTION
[0010] The present disclosure provides for a method of improving the grinding of a bauxite containing slurry during the grinding stage of an alumina extraction comprising: adding an effective amount of one or more non-ionic surfactants, polyglycols, polyglycol ethers, anionic surfactants, anionic polymers, or a combination thereof to said bauxite containing slurry during the grinding stage of an alumina extraction process.
DETAILED DESCRIPTION OF THE INVENTION
[0011] There are many different types of process plants, e.g. Bayer process plants, which serve to extract alumina from bauxite. This disclosure serves to capture all types of process plant operations.
[0012] In one embodiment, the grinding occurs in at least one of the following mills: a ball mill, a rod mill, and a hammer mill.
[0013] Many different types of chemical species may be utilized to improve the grinding of bauxite containing slurry. In general, non-ionic surfactants, polyglycols, polyglycol ethers, anionic surfactants, and a combination thereof may be utilized to improve grinding efficiency. These chemicals may be added alone or in combination with one another.
[0014] Non-ionic surfactants may be utilized to improve the grinding of a bauxite containing slurry in an alumina extraction process. There are many different types of non-ionic surfactants known to those of ordinary skill in the art.
[0015] In one embodiment, the non-ionic surfactants are selected from the group consisting of: oxyalkylated alcohols; ethoxylated alcohols; propoxylated alcohols; polyether polyol; propoxylated glycerine/sucrose; ethylene oxide/propylene oxide block copolymer; ethoxylated alkylphenols; ethoxylated octylphenols; ethoxylated nonylphenols; ethoxylated nonylphenols/tall oil fatty acid; fatty alcohol ethoxylate; alkylphenol ethoxylate; fatty acid ethoxylate; fatty amide ethoxylate; fatty amine ethoxylate; alkyl glucoside; sorbitan alkanoate; ethoxylated sorbitan alkanoate; and a combination thereof.
[0016] Ethoxylated alcohols include Tergitol® 15-S-15, Tergitol® 15-S-12, and Tergitol® 15-S-9, which are all available from The Dow Chemical Company, Midland, Mich.
[0017] Polyether polyols include Voranol-446, which is available from The Dow Chemical Company. Voranol 446 contains propoxylated glycerine and sucrose.
[0018] Ethylene oxide/propylene oxide block co-polymers include PLURONIC® and PLURONIC® R, which are available from BASF Corporation.
[0019] Ethoxylated nonylphenols are available from Nalco Company, Naperville, Ill.
[0020] Polyglycols may be utilized to improve grinding of a bauxite containing slurry in an alumina extraction process. There are many different types of polyglycols known to those of ordinary skill in the art. Polyglycols include DOWFROTH® 250, which is available from The Dow Chemical Company. DOWFROTH 250 contains a mixture of polyglycols and polyglycol ethers.
[0021] In one embodiment, the polyglycols are polypropylene glycols. Polypropylene glycols are available from Nalco Company, Naperville, Ill.
[0022] In another embodiment, the polyglycols have a number average molecular weight of from about 200 daltons to about 1200 daltons.
[0023] In another embodiment, the polyglycols have a number average molecular weight of from about 400 daltons to about 800 daltons.
[0024] Anionic surfactants may be utilized to improve grinding of a bauxite containing slurry in an alumina extraction process. There are many different types of anionic surfactants known to those of ordinary skill in the art. Anionic surfactants are available from Nalco Company, Naperville, Ill.
[0025] In one embodiment, the anionic surfactants are selected from the group consisting of: alkyl sulfate; alkyl ethercarboxylate; alkylbenzene sulfonate; dialkyl sulfosuccinate; alkyl phosphate; alkyl etherphosphate; tall oil fatty acid/ethoxylated nonylphenol; dioctyl sulfosuccinate; and a combination thereof.
[0026] Anionic polymers may be utilized to improve grinding of a bauxite containing slurry in an alumina extraction process.
[0027] In one embodiment, the anionic polymers are terpolymers.
[0028] In another embodiment, the anionic polymers are terpolymers of acrylate, acrylamide, and acrylosulphonate.
[0029] In another embodiment, the anionic polymers are acrylic acid containing polymers.
[0030] In another embodiment, the anionic polymers are sulfonated.
[0031] In another embodiment, the anionic polymers are acrylic acid/methacrylate copolymers.
[0032] The various types of chemical species may be added to slurry via different routes. The chemical species may be mixed with the liquor (e.g. spent or evaporated strong) that is added to a mill, or with a bauxite containing slurry, which is added to the mill. Other modes and methods of addition would be apparent to one of ordinary skill in the art.
[0033] The bauxite containing slurry may have various physical and chemical properties.
[0034] In one embodiment, the bauxite containing slurry is an alkaline slurry.
[0035] In another embodiment, the bauxite containing slurry is at an elevated temperature of less than about 110° C.
[0036] In another embodiment, the bauxite containing slurry is at an elevated temperature from about 65° C. to about 100° C.
[0037] In another embodiment, the chemical species is in liquid form at ambient temperature and ambient pressure.
[0038] One of ordinary skill in the art could determine the amount of chemical species that should be added to the bauxite containing slurry so that there is an improvement in the grinding of the bauxite containing slurry. Such factors, as the chemical species, the slurry components, and viscosity of the slurry, are important in determining the amount of chemical species that should be added to the bauxite containing slurry. Concentrations expressed in this application are based upon the neat solution of chemical species or product combination if more than one species is applied.
[0039] Preferably, an effective amount of chemical species is about 10 ppm to about 1000 ppm. In one embodiment, the effective amount of chemical species is greater than about 10 ppm.
[0040] In another embodiment, the effective amount of chemical species is from about 150 ppm to about 500 ppm.
[0041] The following example is not meant to be limiting.
EXAMPLE
[0042] In this work the grinding efficiency will be assessed by a Grind Index, herein defined as the ratio of the change in the particle size fraction versus the maximum achievable reduction for a specific size faction (e.g. −500 micron or −150 micron) as shown in the equation below:
[0000]
Grind
Index
-
500
=
(
P
final
-
P
initial
)
(
100
-
P
initial
)
[0043] P initial is initial portion of the sample that passes through a screen (e.g. −150 micron fraction/−500 micron fraction).
[0044] P final — is the post-grind portion of the sample that passes through a screen (e.g. −150 micron fraction/−500 micron fraction).
[0045] The basic test method uses small 1 L lab scale grinding bottle. All the Bauxite used in this work was Jamaican and was pre-sized to a “coarse” fraction between −3.36 mm to +1.7 mm, using a ASTM-E11 # 6 mesh screen (nominal pore size is 3350 micron) and ASTM-E11 #12 (nominal pore size is 1700 microns) mesh screen. Each 1 L mill consisted of a plastic bottle (internally baffled) and charged with 1.00 Kg of Zirconia grinding media (⅜″×⅜″)—both are available from Coleparmer. Each test bottle was charged with the appropriate amount of moist bauxite and then a specific quantity of spent liquor (preheated to 90° C.) was added to give the desired bauxite slurry solids, e.g. 30, 35 or 40% solids. Then using a micro-liter syringed the required amount of the reagent was added to the bottle to give the desired dosage, e.g. about 150 ppm to about 900 ppm.
[0046] The bottle was sealed and then rolled on its side in an oven at 80° C. for a specific period of time, typically 30 or 40 min. at a constant speed of 14 revolutions per minute (rpm). Thus for each treated and untreated test, the grinding time and rate (rpm), temperature, caustic, percent solids and media charge were constant. At the completion of each test the slurry was transferred to a metal pot and the Static Yield Stress was measured using a YR-1 yield rheometer (available from Brookfield Engineering). Following this the slurry was wet sieved through a series of screens, e.g., a 500 μm mesh screen and then a 150 μm mesh screen. The screen retains were then dried in an oven and the mass was used to compute the Grinding Index for the 500 μm and 150 μm fractions. The results obtained for the two product chemistries A (DVS4M006, an ethoxylated alcohol, available from Nalco Company) and B (TX12772, a low molecular dispersant terpolymer of acrylate, acrylamide, and acrylosulphonate, available from Nalco Company) are given in Tables I and II respectively.
[0047] As expected the Grind Index (“G.I.”) increases with milling time and decreases as solids increases. Thus at a constant media charge the duration of milling and the amount of solids to be ground influence the grinding efficiency. However, with the addition of between about 150 ppm to about 900 ppm of the grinding aid, the grind index consistently improves by approximately 0.01 to about 0.025 while the viscosity of the slurry is reduced, as noted by a significant decrease in the static yield stress for the treated slurry versus that of the untreated slurry.
[0000]
TABLE I
Lab Milling Test Results with Sample A
(an alcohol ethoxylate surfactant).
%
Milling
Dose,
G. I.
G. I.
Yield
Solids
Time, min
ppm
(500 μm)
(150 μm)
Stress, Pa
35
25
0
0.900
0.757
n.d.
237
0.924
0.789
n.d.
35
30
0
0.920
0.800
3.6
243
0.949
0.815
2.0
35
40
0
0.930
0.870
11.1
436
0.940
0.890
6.8
40
30
0
0.870
0.700
8.0
156
0.880
0.715
4.1
All tests involved a milling temperature of 80° C. at a rate of 14 rpm.
n.d. = not determined;
Pa = pascals
[0000]
TABLE II
Lab Milling Test Results with Sample B
(an anionic terpolymer dispersant).
%
Milling
Dose,
G. I.
G. I.
Yield
Solids
Time, min
ppm
(500 μm)
(150 μm)
Stress, Pa
30
45
0
0.918
0.944
n.d.
232
0.937
0.955
n.d.
35
40
0
0.931
0.878
11.1
871
0.946
0.889
1.0
40
35
0
0.943
0.751
12.1
405
0.960
0.770
9.3
All tests involved a milling temperature of 80° C. at a rate of 14 rpm.
n.d. = not determined;
Pa = pascals
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The present disclosure pertains to a method of improving the grinding of a bauxite containing slurry during the grinding stage of an alumina extraction process. Specifically, an effective amount of one or more non-ionic surfactants, polyglycols, polyglycol ethers, anionic surfactants, anionic polymers, or a combination thereof are added to said bauxite containing slurry during the grinding stage of an alumina extraction process to achieve an improved effect.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/134,958 filed Jun. 6, 2008, which claims the benefit of U.S. Provisional Patent Application No. 60/933,934 filed Jun. 8, 2007, both of which are incorporated herein by reference in their entireties for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND
[0003] The present invention relates generally to the configuration and deployment of pressure control equipment used in drilling subsea wells. More particularly, the present invention relates to subsea blowout preventer stack systems.
[0004] As drilling rigs venture into ever increasing water depths and encounter new challenges, well control has become increasingly problematic. As costs of floating mobile offshore drilling units escalate, traditional time-intensive operations are constantly being re-evaluated in an effort to reduce overall non-drilling time, thereby increasing the drilling efficiency of the rig.
[0005] One of the most time-intensive operations is running the riser, which provides a plurality of parallel fluid conduits between the drilling rig at the surface and the blowout preventer (BOP) stack coupled to the wellhead at the seafloor. In order to facilitate handling of the riser on the rig, the riser is usually constructed by connecting a number of joints that are generally less than fifty feet in length. The riser is “run” by connecting a joint of riser to the BOP stack, lowering the riser-connected BOP stack a short distance, and then connecting another joint of riser to the uppermost end of the riser string. This process continues until the BOP stack is lowered to the wellhead at the seafloor.
[0006] In water depths in excess of 5,000 ft., running the riser generally takes several days to complete. Thus, minimizing the number of times the riser must be run is critical to minimizing the time needed to drill and complete a well. Since the BOP stack is installed at the very bottom of the riser, attempts to increase the amount of time that the BOP stack can stay on the wellhead are being explored. One factor limiting the time a BOP stack can stay on the wellhead is for maintenance of the ram BOP packer seals. Ram BOP packer seals have a limited useful life and once that limit is reached the ram BOP cannot be used until the seals have been replaced.
[0007] One common way to improve the time a BOP stack can stay on the wellhead is to increase the number of useable ram BOP cavities in the BOP stack to the point of having a “primary” and “secondary” ram BOP cavity for each size installed. In this way, the time that a BOP stack can remain operational on the wellhead would be effectively doubled. However, simply increasing the number of ram BOP cavities in a subsea BOP stack presents its own set of new challenges, such as increasing the size and weight of the BOP stack.
[0008] Drilling in deep water has often utilized subsea BOP stacks having four to six ram BOP cavities. Increasing the number of ram BOP cavities, such as to eight or ten cavities would increase the weight of the BOP stack, in some cases to a million pounds or more. Many existing rigs do not have the capacity to handle and operate such a BOP stack. In order to safely operate such a system, enhancements would be required to not only the BOP stack handling equipment on the rig, but also to the drill floor equipment, the drawworks and other hoisting equipment, the rotary table, the derrick, and the riser. Enhancing all of this equipment would likely require expanding the basic rig design to allow it to carry the additional weight of all the enhanced equipment systems and provide room for handling and storing the BOP stack.
[0009] Thus, there remains a need to develop methods and apparatus for allowing improved redundancy and operational times of subsea BOP stacks in order to overcome some of the foregoing difficulties while providing more advantageous overall results.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0010] The embodiments of the present invention are directed toward methods for deploying a subsea blowout preventer stack system comprising a lower marine riser package, a blowout preventer stack with a first ram blowout preventer, and an additional blowout preventer package releasably coupled to the blowout preventer stack and comprising a second ram blowout preventer. The subsea blowout preventer stack assembly can be deployed by coupling a drilling riser to the lower marine riser package that is releasably connected to the blowout preventer stack. The lower marine riser package and blowout preventer stack are then lowered toward a subsea wellhead and landed on the additional blowout preventer package that is already in place on the subsea wellhead. In certain embodiments, neither a drilling rig nor the drilling riser is used to deploy and land the first additional blowout preventer package on the subsea wellhead. During drilling operations, the ram blowout preventers in the first additional blowout preventer package can be used as the primary blowout preventers, leaving the ram blowout preventers in the blowout preventer stack unused.
[0011] In one deployment method, a first additional blowout preventer package is deployed on a first wellhead and a second additional blowout preventer package is deployed on a second subsea wellhead. The BOP stack is landed on the first additional blowout preventer package and drilling operations performed through the first wellhead using the ram blowout preventers of the first additional blowout preventer package as the primary blowout preventers. Once drilling is complete at the first wellhead, the blowout preventer stack is disconnected from the first additional blowout preventer package landed on the second additional blowout preventer package. In this method, the blowout preventer stack can stay subsea while drilling several wells using more than one additional blowout preventer package.
[0012] In some deployment methods, a second additional blowout preventer package is deployed to a subsea parking pile. Once the useful life of the first additional blowout preventer package has been reached the blowout preventer stack is disconnected from the first additional blowout preventer package and landed on the second additional blowout preventer package. The first additional blowout preventer package is then disconnected from the subsea wellhead and retrieved to the surface while the blowout preventer stack and the second additional blowout preventer package are landed on the subsea wellhead. Thus, the blowout preventer stack can remain subsea with minimal disruption to the drilling program while the additional blowout preventer packages are retrieved and maintained.
[0013] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
[0015] FIG. 1 is an elevation view of a blowout preventer stack system constructed in accordance with embodiments of the present invention;
[0016] FIG. 2 is an isometric view of a blowout preventer stack system constructed in accordance with embodiments of the present invention;
[0017] FIGS. 3A and 3B illustrate the deployment and utilization of a blowout preventer stack system constructed in accordance with embodiments of the present invention with a single wellhead;
[0018] FIG. 4 illustrates the deployment and utilization of a blowout preventer stack system constructed in accordance with embodiments of the present invention with a single wellhead and a parking pile; and
[0019] FIGS. 5A-5C illustrate the deployment and utilization of a blowout preventer stack system constructed in accordance with embodiments of the present invention with a plurality of wellheads.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring now to FIG. 1 , subsea BOP stack system 10 comprises lower marine riser package (LMRP) 12 , BOP stack 14 , and additional BOP package (ABP) 16 . Stack system 10 is shown in FIG. 1 landed on subsea wellhead 18 . LMRP 12 comprises a flex joint/riser connector 20 , annular BOP 22 , wellbore connector 23 , control pods 24 , and choke/kill line connectors 26 . BOP stack 14 comprises annular BOP 22 , ram BOP's 28 , choke/kill line connectors 26 , choke/kill valves 30 , wellbore connector 32 , and auxiliary control pods 34 . ABP 16 comprises ram BOP's 28 , choke/kill valves 30 , and wellbore connector 32 .
[0021] LMRP 12 and BOP stack 14 are coupled together by wellbore connector 23 that is engaged with a corresponding mandrel on the upper end of stack 14 . As is shown in FIG. 2 , BOP stack 14 is similarly coupled to ABP 16 by connector 32 that engages mandrel 33 on ABP 16 . Both LMRP 12 and BOP stack 14 comprise re-entry and alignment systems 40 that allow the LMRP 12 /BOP stack 14 and stack 14 /ABP 16 connections to be made subsea with all the auxiliary connections (i.e. control pods, choke/kill lines) aligned. Choke/kill line connectors 26 interconnect choke/kill lines 36 and choke/kill valves 30 on stack 14 and ABP 16 to choke/kill lines 38 on riser connector 20 .
[0022] Control pods 24 of LMRP 12 provide control signals to BOP stack 14 while auxiliary control pods 34 on BOP stack 14 provide control signals to ABP 16 . In certain embodiments, ram BOP's 28 in ABP 16 are controlled by auxiliary control pods 34 , which may be communicatively linked to control pods 24 via umbilical jumpers or some other releasable connection. In certain embodiments, the control functions for rain BOP's 28 of ABP 16 (as well as control functions for other equipment) may be integrated into control pods 24 on LMRP 12 , thus eliminating the need for auxiliary control pods 34 . Because ABP 16 is operated with BOP stack 14 , hydraulic accumulator bottles 42 mounted on the BOP stack can be used to support operation of the ABP. ABP 16 may also comprise a remotely operated vehicle (ROV) panel that provides control of the ABP functions by an ROV.
[0023] LMRP 12 and BOP stack 14 are similar to, and can operate as, a convention two-component stack assembly. ABP 16 is installed between wellhead 18 and BOP stack 14 and provides additional rain BOP's 28 to provide redundancy and increase effective service life. In certain embodiments, ABP 16 will not be lowered from the rig to the wellhead on a conventional riser with the rest of the BOP stack but will be deployed separately. This separate deployment can be accomplished on drill pipe, heavy wireline, or any other means, either from the drilling rig if it has a dual activity derrick, from another rig (perhaps of lesser drilling capabilities), or from a heavy duty workboat or tender vessel. In addition to being run, the ABP 16 could be stored and serviced by a vessel other than the drilling rig, thus eliminating the need for additional storage space and handling capacity on the drilling rig.
[0024] Referring now to FIGS. 3A and 3B , a single ABP 16 can be landed on wellhead 18 via drill string, wireline, or other non-riser system by service vessel 48 prior to drilling rig 50 arriving on site. Drilling rig 50 would then run the BOP stack 14 and LMRP 12 assembly on conventional drilling riser and land the stack on ABP 16 . Normal drilling operations could utilize the rain BOP's of ABP 16 until their useful life was reached. At that point, drilling could continue with the rain BOP's of BOP stack 14 without disturbing the stack assembly, thus increasing drilling time before having to bring the stack to the surface for maintenance.
[0025] Referring now to FIG. 4 , a drilling site may comprise a wellhead 18 and a parking pile 52 . Parking pile 52 provides a location for the subsea storage of an additional ABP 16 . A first ABP 16 can be run as described above in reference to FIG. 3A by service vessel 48 . BOP stack 14 and LMRP 16 can then be run by a drilling rig and drilling operations performed using the rain BOP's in ABP 16 . Before the useful life of the rain BOP's in ABP 16 is reached, a replacement ABP 16 A can be run by a service vessel and landed on parking pile 52 . When the first ABP 16 needs to be serviced, stack 14 and LMRP 12 can be disconnect from the ABP but remain subsea. Once ABP 16 is pulled to the surface for servicing, replacement ABP 16 A can be disconnected form parking pile 52 and landed on wellhead 18 . Replacement ABP 16 A can be moved from parking pile 52 to wellhead 18 by drilling rig 50 by landing BOP stack 14 on ABP 16 A and then moving the entire assembly together. Replacement ABP 16 A can also be moved onto wellhead 18 by a service vessel as BOP stack 14 is supported by the drilling rig.
[0026] Referring now to FIGS. 5A-5C , multiple ABP systems 16 A- 16 B can be used to drill multiple wells on a plurality of wellheads 18 A- 18 C. A first ABP 16 A can be deployed onto wellhead 18 A with BOP stack 14 and LMRP 12 being run and landed atop ABP 16 A and drilling operations commenced. While the first well is being drilled, a second ABP 16 B is deployed and landed onto the next wellhead 18 B. When the first well is completed, the BOP stack 14 and LMRP 12 can simply be unlatched, lifted, relocated the second wellhead 18 B and landed on second ABP 16 B. While the second well is being completed, the first ABP 16 A can be retrieved from the first wellhead 18 A and moved to a third wellhead 18 C, or brought back to the surface for maintenance or repair.
[0027] Under any of the uses of an ABP as described above, the rain BOP cavities in the ABP can be considered the primary cavities while the rain BOP cavities in the BOP stack would then be considered the secondary cavities. This would allow the BOP stack and LMRP to stay down almost indefinitely because the secondary cavities in the BOP stack would only be utilized after the primary cavities in the ABP were rendered inoperable. And the primary BOP cavities in the ABP could be retrieved to the surface and maintained while the BOP stack and LMRP were drilling atop another ABP.
[0028] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied, so long as the override apparatus retain the advantages discussed herein. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
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Methods for deploying a subsea blowout preventer stack system comprising a lower marine riser package, a blowout preventer stack with a first ram blowout preventer, and an additional blowout preventer package releasably coupled to the blowout preventer stack and comprising a second ram blowout preventer. The subsea blowout preventer stack assembly can be deployed by coupling a drilling riser to the lower marine riser package that is releasably connected to the blowout preventer stack. The lower marine riser package and blowout preventer stack are then toward a subsea wellhead and then landed on the additional blowout preventer package that is coupled to the subsea wellhead.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the electrical contacting of insulated conductors by means of an insulation displacement contact. In particular, the invention relates to an insulation displacement contact and a contacting device with an insulation displacement contact.
2. Description of Related Art
For the electrical contacting of cable strands (insulated stranded cable conductors or wires), electrically conductive terminals are often used, which can be clamped onto and form an electrical contact with a contacting region of the conductor, which has been de-insulated in a previous step. In addition to these, insulation-piercing technologies are well known. These have to do with electrically conductive contacting elements, which are designed such that they can break through the electrical insulation at the contacting site and contact the underlying conductor without prior de-insulation. The best-known in this regard are the insulation displacement contacts (IDC), in which the cable strands are pressed between two blades in an area of the contact that is furnished with a bifurcated, bladed area, until the insulation is cut through, whereby not only is the conductor contacted, but the cable strand is also held fast at the same time. Also well known are the so-called piercing contacts, with which the insulation is punctured by at least one contacting point.
While the piercing contacts require a separate, independent cable strand holder, insulation displacement contacts are self-centering and have been widely tested and proven. The known insulation displacement contacts, as described for example in the introductory paragraph of U.S. Pat. No. 6,866,536, are however as a rule only appropriate for use with conductors that have a precise pre-defined diameter and a small range on either side of this diameter. In addition, they require a sizeable installation height and in most embodiments can only create a contact from one conductor to one other. Moreover, in general they are only appropriate for a single wiring of a conductor or at most only a very few wiring procedures, since they may be considerably plastically deformed when the cable strand is inserted between the blades. The extent of the plastic deformation depends in many cases upon how deeply the cable strand, and with it the conductor, is inserted between the blades of the IDC, so that the already limited degree of re-usability is also an unpredictable value.
An electrical terminal with an insulation displacement contact which is appropriate for the simultaneous contacting of two conductors is disclosed in DE 1990 98 25 or DE 20 2005 012 792 U. For this purpose, the insulation displacement contact is formed as a pincer-shaped (or dredging-shovel-like) curved insulation displacement contact (bended stamped piece), wherein the depth of the pincers created thereby (corresponding to the length of the curved insulation displacement contactor) is large enough to allow the inclusion of two conductors. This solution, thus, has the advantage that in contrast to conventional insulation displacement contacts, the spring force that is exerted on the conductor is not a function of the depth to which it is introduced; this first makes possible the simultaneous introduction of two equally thick (in cross section) conductors. However, it is disadvantageous that in this design a larger material strength is assumed, or the contact strength is relatively limited in relation to the overall size, and that the spring force is given by the thickness of the plate, and thus is a parameter that can only be manipulated—with little flexibility—through the thickness and selection of the material. Furthermore, the installation height of one of these insulation displacement contacts is relatively large, so that although it is appropriate for use in the terminal described in DE 20 2005 012 792 U, it is problematic when used with well-known plug systems. Furthermore, this design is not appropriate for the wiring of through-running cable strands.
EP 0 344 526 depicts a terminal block for a cable jack with a clip which is set into an insulating body. The clip exhibits on one side a terminal contact and on the other side a separation or clamping mechanism. In one embodiment, a bipartite connection piece connects proximally between the terminal contact and the V-shaped clamp mechanism to the terminal contact. The arrangement is however not appropriate for the introduction of an elastic spring force through the clamping mechanism such that a plastic deformation will occur during the insertion of a conductor. In addition, the clamps require a substantial installation height. Furthermore, due to the arising plastic deformation, they are in general only appropriate for a single wiring of a conductor or at the most only very few wiring procedures.
BRIEF SUMMARY OF THE INVENTION
It is the object of the invention to provide an insulation displacement contact for joining, which overcomes the disadvantages of the state of the art and which in particular is appropriate for the multiple wiring of multiple conductors (advantageously with different conductor cross sections) one after the other. Solutions which actually enable the wiring together of cable strands with different diameters are preferred. A further object of the invention is the provision of a corresponding contacting device.
These objects will be fulfilled by the invention, as defined in the patent claims.
An insulation displacement contact according to the invention is substantially characterized in that as a whole it includes a cutter section with two opposing contact blades next to two fork sections, which both account for a clamping force, with which the two contact blades (during the wiring) are pushed against each other, as soon as a conductor is inserted between the contact blades and these are thereby pushed away from one another. Therein—with respect to a wiring direction, i.e. for example in a direction running parallel to the cutting edge of the blade, in which the conductor is moved between the blades while being pressed in—the one fork engages proximally (i.e. on the side from which the conductor is introduced) and the other fork distally (i.e. on the opposite side), such that the two contact blades are pressed together at four points. The fork sections are angled to the cutter section, i.e. they do not run in the same plane as the cutter section.
That the fork sections form an angle with the cutter section does not mean that they necessarily must be partially or entirely flat. In addition, it is not excluded that at least one of the sections forms an angle of 180° to the fork and thereby is parallel to it. Rather here ‘forms an angle’ means only that the respective fork section and the cutter section do not extend in a common plane and preferably also do not extend parallel to one another in the same direction (i.e. the respective fork section is not angled in a parallel plane and back in the same direction). As described in detail below, preferably (in different configurations) the two fork sections are bent at least 90°, such that the installation height of the physical dimension of the cutter section corresponds to and at least does not substantially exceed these.
The two fork sections each have the function of an elastic spring, and preferably they are arranged such that they are linked by the cutter section in the case of an appropriately modulated insertion of a conductor, and for example, do not individually function as supplementary clamps; this would impair the spring action and also preclude an ideal spring form, which is discussed below in more detail.
The fork sections are arranged such that each of them works from one side as a spring clamp. Each of the two fork sections, thus, constitutes for itself an independent elastic spring. This means that in the pushing apart of the contact blades to a thickness of one of the conductors to be contacted, in the area of the proximal bending line (i.e. the line at which the cutter section merges into the first fork section) as well as in the region of the distal bending line (i.e. the line at which the cutter section merges into the second fork section) the first as well as the second fork is substantially elastically and either not, or else to a very small extent when compared to the elastic deformation, plastically deformed.
This also means that in general, during the insertion of the conductor, the contact blades do not (or at most not substantially) open in a V-shaped manner with an opening angle that increases with the insertion depth; on the contrary: preferably during insertion the contact blades remain approximately parallel to one another (or even eventually assume a configuration slightly opened to the distal side as the conductor is positioned in a distal region). The deflection of the fork spring is therefore essentially only dependent on the diameter of the conductor and not on the position of the conductor between the contact blades.
For this purpose, the spring constants of the two springs formed by the first as well as the second forks are of a similar order of magnitude (if one takes as a benchmark the force needed for a deflection in the area of the respective bending line), i.e. the spring constants are dissimilar at most by a factor of 3 (i.e. 1/3F 1 <F 2 <3F 1 ), preferably at most by a factor of 2, and particularly preferably they are substantially the same, i.e. they differ from one another at most by a factor of 1.5. Ideally the two spring constants are practically identical, i.e. they differ from one another by at most about 20%.
These criteria can be realized particularly well if the prongs of the first fork are approximately the same length as the prongs of the second fork. For example, the lengths are at most 50% and particularly preferably at most 30% different from one another.
According to a preferred embodiment the forms of the two forks are optimized for as large as possible of an elastic area in relation to the length of the forks, which also means that they can store a comparatively large amount of potential energy. Conventional insulation displacement contacts have in the region of the bridge between the blades an approximately circumferential inner contour line, to which a region adjoins, in which two parallel fork prongs are formed. The outer contour line of conventional insulation displacement contacts is often sectionally rectangular with rounded edges. It has been shown however that such a form is not optimal, because in the area of the bridge very high forces appear, which result in permanent (plastic) deformations. Although the invention does not exclude such forms, a geometry of the two forks that differs from this is recommended. Preferably the forks are formed such that in a deflection, an (elastic) deformation does not only occur in the bridge, but rather the whole length of the fork contributes to the storage of potential energy. In particular, it is preferred that at least one, preferably more than one of the following design criteria are realized:
An inner contour line of the corresponding fork is symmetrical relative to a plane of symmetry through the apex, and a distance m, defined as the distance from the plane of symmetry to a point of intersection between the inner contour line and a plane perpendicular to the fork plane at an angle of 45° from the plane of symmetry, is such that m≦3d/8, where d is the distance between opposing points on the inner contour line at the site of greatest distance between the fork prongs. An outer contour line of the corresponding fork is symmetrical relative to a plane of symmetry through the apex, and the distance n, defined as the distance from the plane of symmetry to a point of intersection between the outer contour line and a plane through the outer contour line apex and a plane perpendicular to the fork plane and at an angle of 45° from the plane of symmetry, is such that p/4≦n<p/2, where p is the distance between opposing points on the outer contour line at the site of greatest distance between the fork prongs. The corresponding fork has an inner contour line, which at the apex comprises a non-zero radius of curvature r Si and tangents to the inner contour line at a distance of a radius of curvature r Si from the apex, which distance is measured radially to the circle of curvature, will be at an angle different 0° to each other, wherein the angle is preferably at least 10°, at least 20° or at least 30°. In other words, if a line is drawn perpendicular to the plane of symmetry and through midpoint of the circle of curvature at the apex, it will intersect the inner contour line at two points. The tangents to the inner contour line at these two points will themselves intersect to form a non-zero angle, wherein the angle preferably amounts to at least 10°, at least 20° or at least 30°. For example, the inner contour line runs nearly elliptically, i.e. it curves with the greatest curvature in the area of the apex. The width of the fork prongs steadily decreases as a function of distance from the apex. The outer contour line runs in a course analogous to, for example, the inner contour line, (it can also be elliptic), wherein at the apex it comprises a non-zero radius of curvature r Sa and if a line is drawn perpendicular to the plane of symmetry and through midpoint of the circle of curvature at the apex, it will intersect the outer contour line at two points. The tangents to the outer contour line at these two points will themselves intersect to form a non-zero angle, wherein the angle preferably amounts to at least 10°, at least 20° or at least 30°. The outer contour line of the corresponding fork qualitatively has a course that is analogous to the course of the inner contour line, for example the two are substantially elliptical with different ellipse parameters. If the inner and/or the outer contour lines are parameterized, then the first and preferably also the second derivatives of the coordinates with respect to the parameterizing variables are constant.
The first two mentioned design criteria assume that the contour line is symmetrical. In a general case, in which the corresponding (inner or outer) contour line is not necessarily symmetrical relative to a plane of symmetry, the distance m and/or n is defined as follows: in a blank of an insulation displacement contact those lines are intersected by the inner and/or outer contour lines that comprise an angle of 45° to the tangents of the inner and/or outer apex. The distance from the respective intersection point to the perpendicular of the named tangent corresponds to the value m and/or n, for which the above conditions hold true. In asymmetrical cases the two 45° straight lines can result in different values m 1 , m 2 , n 1 , n 2 ; the above conditions can then respectively be valid for one of these two values or for both. It can also be that the corresponding conditions hold true for only the inner contour line and not for the outer, or vice versa.
The approach according to the invention has the first, direct advantage that with a long enough cutter section two conductors are simultaneously connectable, i.e. a conductor that is clamped in one position does not preclude that sufficient clamping force may be applied to a second conductor that is inserted to another position between the contact blades. This is in some circumstances also true if the two conductors do not have exactly the same diameter.
A second advantage of the approach, according to the invention, arises from the advantage that conductors of different diameters are wireable, and indeed reversible. Thus, it can be that a first, thicker conductor, and after this is removed a second, less thick conductor can be reliably held—because due to the approach according to the invention, practically no plastic deformation occurs, provided that only conductors with a diameter in an approved range of diameters are wired.
The fork sections are preferably designed such that an inserted conductor over an entire length of the cutter part is reversibly clampable, i.e. that the clamping force over the entire length is sufficient but not too great, wherein through insertion of a conductor of an intended size the insulation displacement contact will be deformed substantially elastically.
Furthermore, the design with the angled fork sections enables the use of contacting devices (e.g. plugs, adapters, jacks, etc.) of relatively limited installation height. This is particularly the case if the fork sections are angled at least 90° from each other: then the entire installation height can correspond to the height of the cutter section. Overall, it results in an optimal relationship between installation height and elasticity: despite limited installation height, the blades can be displaced relative to one another with elastic deformation by a comparatively very large amount.
The geometry of contact elements designed according to the invention also makes possible that the insulation displacement contact can be formed as a whole unit with insulation displacement openings situated in opposed directions or as a double contact element with two insulation displacement contact sections at different sites.
Preferably, the insulation displacement contact is designed such that a through-running conductor can be contacted, without needing to be snapped off or even cut. In particular, a conductor that is to be contacted should preferably be contacted substantially (under application of a force) only by the contact blades of the insulation displacement contact; the fork sections can thereby be optimally formed for their function as elastic springs.
According to a particularly preferred embodiment, one of the two fork sections is angled at more than 90°, while the other is angled to approximately 90°. The first, more than 90° angled fork section therein corresponds to the first section, which adjoins the proximal end of the cutter section (i.e. the “upper” fork section). In this preferred embodiment, the wiring of a through-running conductor is possible; the fork bridges of the two fork sections both run “underneath” the conductor.
In a first variant the first and second fork sections are angled to the cutter section such that they, relative to a cutter-section plane, lie on the same side of the cutter section. This configuration makes it possible that without additional requirement of space the first fork section must only be angled to a few degrees more than 90°—e.g. to about 100-140°. This achieves a particularly advantageous unstressed force distribution and makes possible the use of blades that are themselves rigid. The configuration is also advantageous with respect to the dimensioning, such that comparatively large first and second forks can nevertheless be used, wherein as the fork size is increased, the insulation displacement contact as a whole only increases in size in one direction.
In a second variant, the first and second fork sections lie on different sides of the cutter section plane. This variant is especially advantageous if the first fork section is angled at 180° or at another comparatively large angle—for example between 150° and 190°. The insulation displacement contact as a whole thus has the form of a bow with, for example, an approximately perpendicularly angled (second) fork, wherein the bow is formed by the first fork and the cutter section. Again, this is an advantage if the insulation displacement contact as a whole is relatively small: the cable strand can be pushed between the blades by a wiring cap that is put over the bow and approaches close to the blades; it can also be that no element, which would have to be disruptive in the small space between the fork prongs, is necessary for the wiring, i.e. only the conductor comes to rest between the blades.
If the first fork section is angled to a large angle of about 180°, a torque is also applied to it as the two blades are pushed away from one another. Therefore in the second variant the cutter section preferably is designed as (a third) spring element. This has the further advantage that potential energy can also be stored in the cutter section and thereby a plastic deformation of the insulation displacement contact can be further counteracted.
The insulation displacement contact is metallic and one-piece. Preferably, the insulation displacement contact according to the invention is manufactured out of a stamped, bent component (sheet). The deflection of the contact blades and the corresponding spring force that acts against the deflection, thus, act in the sheet plane, and not perpendicularly thereto. This has the advantage, among others, that the relevant spring constant can be nearly arbitrarily determined by the width of the fork prong sections and the arrangement of the fork bridge area, i.e. the spring constant is not exclusively dependent on the sheet thickness, but rather is an independently free parameter. Furthermore, reliable and comparatively economical manufacturing methods can be reverted to.
Also, it is preferred that the cutter section as a whole is substantially flat, i.e. at least the cutting edges and, for example, the entire cutter section runs in a plane without curvatures.
The insulation displacement contact may—particularly in uses for the wiring of comparatively thick conductors—comprise protruding contact spikes in the proximal direction, with which during wiring the insulation of thicker cable strands will be tapped. By this measure, it is made possible that the radial force needed for the penetration of the insulation is restricted to clean cutting, which is achieved particularly well with the advancement according to the invention, by which the elasticity tends to be increased in comparison to the state of the art.
Furthermore, the contact blades may—in each embodiment—be sharpened by punching in their insertion area in order to increase their cutting action.
A contacting device of the kind of the invention comprises a plurality of insulation displacement contacts according to the invention, which are arranged on and/or in one housing. The insulation displacement contacts serve either for the direct contacting of a further element (cable strand of a branched conductor or contact of a device, etc.), in which they also form a jack or plug contact (with jack or plug contact, corresponding distribution board contacts are also meant), or they are contacted and/or contactable in the housing by a jack or plug contact; the housing does not need to be one-piece and it can be imagined that an electrical connection between insulation displacement contacts and cable strands on the one side and/or between insulation displacement contacts and jack or plug contacts on the other side can be established through the bringing-together of the parts of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, preferred embodiments of the invention will be described in more detail by use of figures. In the figures, identical reference numbers indicate similar or analogous elements. Depicted are:
FIG. 1 a perspective view of an insulation displacement contact according to the invention;
FIG. 2 a top view of the blank of an insulation displacement contact according to FIG. 1 (i.e. of the insulation displacement contact in a flat form, as it exists during manufacturing process before bending or as a semi-finished product);
FIG. 3 the wiring of a conductor with a small diameter;
FIG. 4 the wiring of a conductor with a larger diameter;
FIG. 5 the wiring of a conductor using a variant of the insulation displacement contact according to FIG. 1 with a stepped contact area;
FIG. 6 a top view of a further variant of an insulation displacement contact with a cutter for cutting the cable to length;
FIG. 7 a schematic graph which depicts the spring force as a function of the insertion depth of the cable strand;
FIG. 8 a drawing that illustrates the course of curvature of the inner contour of a fork of an insulation displacement contact according to the invention;
FIG. 9 a drawing that demonstrates the criteria for the design of the IDC;
FIG. 10 a schematic depiction of a contacting device according to the invention;
FIGS. 11 and 12 each a view of a further insulation displacement contact according to the invention, which is particularly appropriate for multiple distributor banks;
FIGS. 13 and 14 each a view of a further insulation displacement contact according to the invention; and
FIG. 15 a top view of a blank of an insulation displacement contact according to FIGS. 13 and 14 without the jack contact section.
DETAILED DESCRIPTION OF THE INVENTION
The depictions of FIGS. 2 and 15 correspond to the insulation displacement contacts that are shown in FIGS. 1 and respectively 13/14 in the flat form of a blank, as they exist for example as semi-finished products before being bent into the desired 3-D form; in FIGS. 2 and 15 the bending lines (in reality they are regions around these lines) are respectively also depicted, which define the transition between the cutter section on the one side and the fork sections on the other sides.
The insulation displacement contact 1 depicted in FIGS. 1-4 comprises a cutter section 3 with two blades 3 . 1 , 3 . 2 . In an area of the blades, there are opposing cutting edges 3 . 3 , 3 . 4 which are designed to cut through an insulation 7 . 2 of a conductor 7 . 1 . In this text, “blades” will indicate whole length of the elements that make up the cutter section, thus not only in the area in which the cutting edges exist.
A first fork 4 with two fork prongs 4 . 1 , 4 . 2 connects on the proximal side (in those figures where as for example in FIGS. 1 , 3 and 4 a 3D-view is shown, the proximal side of the cutter section corresponds to the upper side, the distal side to the lower side; the cable strands are inserted “from above”) of the cutter section 2 . On the distal side, the cutter section merges into the second fork 5 with respectively two fork prongs 5 . 1 , 5 . 2 . The fork section that is formed by the first fork 4 is angled with respect to the cutter section by an angle of more than 90°—here approximately 115°. An end area 4 . 4 of the first fork section is, for reasons of space, slightly bent away from a main area of the fork section. The second fork section that is formed by the second fork 5 comprises an angle of about 90° to the cutter section. This arrangement makes possible the wiring of a through-running, uncut conductor, as will be more fully illustrated below with reference to FIG. 10 .
In the illustrated embodiments, a jack contact section 6 continues on from the second fork section, which is formed in a manner appropriate to the geometric position in the contacting device, such that a plug contact of a plug can establish a dependable electrical contact.
By the insertion of a cable strand 7 (conductor 7 . 1 with insulation 7 . 2 ) the two blades 3 . 1 , 3 . 2 are pushed apart from one another. As is shown schematically in FIG. 3 by double arrows, this pushing-apart works at four points against an elastic counter-force F 1,2 , which is exerted by the fork prongs of the first and second fork. This elastic counter-force results from the forks 4 , 5 being elastically deformed in their respective planes, as the fork prongs are pushed apart from one another.
In the depicted embodiment each of the two blades 3 . 1 , 3 . 2 also each comprises a contacting spike 3 . 5 , 3 . 6 . As one can see in FIG. 4 , these contacting spikes can tap into and penetrate into the cable strand insulation during the wiring of thicker cable strands 7 . This contributes the positive effect that the radial (with respect to the cable strand) force that is borne through the insulation displacement contact and with this the maximal deflection of the blades away from one another during the wiring process can be reduced: as it were, at most only the inner part of the insulation must be broken through in a radial cutting movement. This characteristic thus causes the range of thicknesses that can be wired and can be done so reversibly to be further increased.
The variant of the insulation displacement contact that is depicted in FIG. 5 is distinguished from the insulation displacement contact according to FIG. 1 in that the cutting edges are stepped, thus in an upper, proximal section are more distant from one another than in a lower section. By this means, the range of possibly manageable cable strand thicknesses can be yet further enlarged: thin cables are pushed completely to the bottom, while thicker cables remain in the upper area.
The variant according to FIG. 6 has further the characteristic that a length-cutting blade 8 for cutting the cable strand 7 to length is present; this variant is advantageous in combination with the utilization of non-through-running cables. At the jack contact section 6 (in other embodiments it can also be a plug contact section) other elements for yet further functions can be present, for instance soldering pins, springs, etc.
In FIG. 7 the solid line shows schematically the force F exerted by the blades on the conductor as a function of the insertion distance s of the cable strand, wherein for an insulation displacement contact the descriptions depicted in FIGS. 1-4 are assumed. Due to the slanted form of the blades in the proximal area, the blades are at first steadily pushed away from one another, which according to Hooke's Law produces an analogous, for example linear, rise in the force. However, as soon as the conductor is in the area in which the cutting edges of the blades are parallel to one another and the insulation at the contact point with the IDC is broken through, the force F remains constant, since the two forks are not further deformed by further insertion.
This markedly distinguishes the insulation displacement contact according to the invention from known insulation displacement contacts (V-technology), these insulation displacement contacts are in the form of a pair of scissors, between whose blades an object is inserted, and which in the course of this insertion open ever wider. A corresponding force curve of a cutter according to the state of the art is shown schematically in FIG. 7 by the dotted line: the force steadily increases as a function of the insertion distance. As a result, in the area of the apex of the state of art insulation displacement contact forces will arise very rapidly and exceed the elastic range even with a normal conductor cross section, and rapid and inevitable plastic deformation will also ensue. A boundary between elastic (reversible) and plastic (irreversible) deformation—in practice naturally fluid and furthermore dependent on the geometrical design of the insulation displacement contact—is illustrated in FIG. 7 by a dashed line.
Preferred embodiments of the insulation displacement contacts according to the invention are furthermore optimized through further means, which make possible as large as possible a spring area of the forks in as small a space as possible. So as depicted in FIG. 8 the forks are preferably distinguished from the forms realized in the state of the art with round inner contour lines in the area of the apex and adjoining thereto parallel fork prongs of constant cross sectional area. In particular, the curvature will preferably not be constant at least in the area of the apex, but rather decrease as a function of distance from the apex.
This is expressed in that, among other things, the following criterion is fulfilled. If at the apex a circle of curvature (dotted in FIG. 8 ) with radius r Si is drawn and tangents (and/or tangential planes 31 . 1 , 31 . 2 ) are drawn for the inner contour line at a distance of r Si , from the apex (i.e. in x-direction in FIGS. 8 and 9 ), the angle between the tangents becomes non-zero. This angle amounts to, for example, at least 10°, or at least 30°, in the depicted example somewhat more than 60°, and preferably its maximum is about 100°.
Analogous considerations can be valid for the outer contour lines, wherein it is particularly advantageous for the outer contour lines if they depart from a form that can be approximated by three rectangular sides with rounded edges between them.
It can further be seen in FIG. 8 that the width of the fork prongs decreases as a function of the distance from the apex—i.e. as a function of the x-coordinate in FIG. 8 .
FIG. 9 depicts further criteria for the inner contour line 21 . 1 and the outer contour line 21 . 2 , which to a greatest possible degree represent an optimization of the elastic spring range of the forks in the smallest possible space. Virtual planes 41 and 42 , which are designed with an angle of 45° to the plane of symmetry 40 (and perpendicular to the plane of the image) are placed through the apex of the inner contour line 21 . 1 and the outer contour line 21 . 2 respectively.
The distance m between on the one side the point of intersection of the virtual plane 41 through the inner apex and the inner contour line 21 . 1 , and on the other side the plane of symmetry 40 represents in classical solutions the half distance d/2 of the two fork prongs at their widest point. According to a preferred embodiment of the invention, m is smaller than this value, for example to a minimum of d/12, particularly preferably to a minimum of d/8 such that it is true that m≦3d/8. This criterion also means the maximum distance of the inner contour lines from the plane of symmetry does not already occur near the apex, but rather is displaced from there.
A realistic lower limit for the value of m lies at, for example, d/12, particularly preferably at a minimum of d/8.
Also for the distance n between on the one hand the point of intersection of the virtual plane 42 through the outer apex with the outer contour line 21 . 2 and on the other hand the plane of symmetry 40 there is—independently—a criterion. In the “classical” solution this amounts to p/2, wherein p/2 is the maximum distance of the outer contour lines from the plane of symmetry. According to the preferred embodiment of the invention, n is yet smaller than p/2 particularly preferably n is not larger than 7p/16. As a lower limit for n the value of p/4 can, for example, be taken.
In a blank of the insulation displacement contact, the planes 41 , 42 are replaced by corresponding lines 41 , 42 , which stand at an angle of 45° to the tangent 43 and/or 44 of the corresponding apex, wherein the distance is then measured from the intersection to the perpendicular 40 of the tangent 43 and/or 44 through the apex; this definition is also valid for non-symmetrically shaped insulation displacement contacts.
FIG. 10 shows schematically a contacting device with an insulation displacement contact 1 as described above. In FIG. 10 , one may also see that on the basis of the selected angle between the cutter section 3 on the one side and the fork sections 4 , 5 on the other side a through-running cable strand 7 may be contacted.
In a addition to a plurality of insulation displacement contacts 1 , the device comprises a housing 12 . This housing is designed such that the plug contact 13 of a plug 14 can project into the housing interior such that the jack contact section 6 of the insulation displacement contact 1 can be contacted.
Ways of arranging the housing of such a contacting device 11 as well as means of guiding the conductor (guiding ridges, etc.) and aids for wiring (for example inclinable or translationally movable wiring caps, etc.) are known to those skilled in the art, and will not be dealt with here in further detail. Of course, other embodiments can be imagined, in which the insulation displacement contact can be designed in and/or on an inclinable or movable element and in the wiring process be moved relative to the stationary cable strand.
The insulation displacement contact according to FIGS. 11 and 12 is distinguished from the one of FIGS. 1 to 4 in that is, for example, specially designed as a contacting device for a multiple-socket connector strip. In the jack contact area 6 multiple jack contact holes 6 . 1 - 6 . 4 are designed, in which, respectively one cylindrical plug contact can be inserted. The slits in the area of the jack contact holes provide the necessary elasticity for the case in which the plug contact itself is rigid. In a plug strip there are two or three, or depending on the plug standard also more, insulation displacement contacts of the type depicted in FIGS. 10 and 11 , wherein the arrangement can be such that the jack contact holes 6 . 1 - 6 . 4 of the different insulation displacement contacts are designed to correspond to a prevalent type of plug.
In place of jack contact holes, or in addition to these, other means of connection can be imagined, for example soldering eyelets or pins, piercing points, etc.
The insulation displacement contact according to FIGS. 13-15 is distinguished from the one of FIGS. 1-4 in that, among other things, the first and second fork are angled on different sides of a plane defined by the cutter section. In this manner, as can also be seen in FIGS. 13 and 14 , the second fork section can be angled to approximately 180°, such that the cutter section 3 and the second fork section 5 together form a bow with two bow limbs, the first fork limb 5 . 1 together with the first blade 3 . 1 forming the first bow limb, and the first fork limb 5 . 2 together with the first blade 3 . 2 forming the second bow limb. Between the bow limbs, a cable strand with the conductor to be contacted must be inserted. This can be achieved with the help of a wiring cap, which for example, can be put over the bow. The form of the insulation displacement contact according to FIGS. 13-15 is thus also particularly appropriate for the design of a comparatively smaller insulation displacement contact, so for example for the wiring of data conductors. In particular a contacting device according to the invention can be designed as the plug or jack of a data conductor, for example as an RJ-45 plug or jack.
A further characteristic of the insulation displacement contact according to FIGS. 13 to 15 is distinguished in the notches 3 . 8 that can be seen in the cutter section. As a result of this notch, the blades 3 . 1 , 3 . 2 concurrently function as spring elements in the same manner as the forks. They can, thus, contribute to the elasticity of the insulation displacement contact as a whole and in addition take up the torsion forces that are caused by the angling of the two forks 4 , 5 relative to one another.
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An insulation displacement contact ( 1 ) according to the invention essentially distinguishes itself in that as a whole it comprises a cutter section with two opposing contact blades ( 3.1, 3.2 ) together with two fork sections which contribute to a clamping force with which the two contact blades are pressed together as soon as a conductor is inserted between the contact blades and they are pushed away from one another. In the process one fork ( 4 ) exerts proximally (i.e. on the side, from which the conductor is inserted) and the other fork ( 5 ) distally (i.e. on the side opposite), such that the two contact blades are pushed together at four points. The fork sections are angled relative to the cutter section ( 3 ), i.e. they do not run in the same plane as the cutter section. The two fork sections each constitute an independent, elastic spring. This means that in they will be substantially elastically and not plastically deformed as a result of the moving-apart of the contact blades ( 3.1, 3.2 ) to the thickness of a conductor to be contacted.
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TECHNICAL FIELD
[0001] This application relates generally to semiconductor devices and device fabrication and, more particularly, to etching polysilicon layers without a separate oxide decapping procedure.
BACKGROUND
[0002] The semiconductor device industry has a market driven need to reduce the size of devices such as transistors, capacitors and electrically conductive interconnects in order to produce smaller integrated circuit devices (ICs). Smaller ICs result in improved operational speed and clock rate, and reduced power requirements in both the standby and operational modes. Smaller ICs need thinner dielectric layers, thinner diffusion layers and more closely spaced conductive interconnect layers, such as doped polycrystalline silicon (poly). Producing these closely spaced (finer pitch) poly lines requires improved poly etching techniques. Micro electro-mechanical (MEM) devices may use etched poly patterns as a portion of the device. Reducing the size of MEM devices increases their utility and decreases their price and power consumption in many cases.
[0003] It is known to improve poly pitch by use of plasma etch techniques to increase the slope of the etched poly sidewall to approaching 90 degrees, and to reduce the amount of sideways etching that occurs under the edge of the photo resist mask. However, plasma etch processes are slow, require substantial expensive equipment, and may have problems with what may be known as etch selectivity ratios. The etch selectivity ratio is the rate of etching of a first material divided by the rate of etch of a second material. A high etch selectivity of a material layer being etched over the underlying layer is important in IC and MEM manufacture, since it allows increased margin for timed etches by providing what may be called an etch stop. The increasingly small and reliable integrated circuits (ICs) devices will likely be used in products such as processor chips, mobile telephones, and memory devices such as dynamic random access memories (DRAMs).
[0004] Thus there exists a need in the art for a simple, inexpensive and uniform poly etch method that has both a high poly etch rate (to decrease manufacturing cost), and high etch selectivity of poly over the underlying single crystal silicon, doped oxide, or other material layers. It is known to etch poly layers using wet chemical etch tanks. Wet etching is simple and inexpensive, but there is an issue with the etch uniformity, both in terms of across the single wafer variations, and in lot to lot variations over time. One reason for this lack of uniformity in poly etching relates to the fact that if a poly layer is exposed to the oxygen in the air, which may be hard to avoid, the surface atoms of the poly oxidize to form what may be called a native oxide. Such a native oxide may be from 10 to 20 Angstroms ( 521 ) in thickness, and the oxide may grow in a few hours. Wet chemical etches that have high poly etch rates and high etch selectivity over underlying oxides may be non uniform since the etching of the poly can not begin until the native oxide, which may be call a cap oxide, is etched (or decapped). Since the thickness of the oxide cap is a variable that depends at least in part on how long the poly layer has been exposed, and the storage conditions, then the amount of time it takes to decap the poly layer before etching begins may result in non-uniform etching.
[0005] It is known to place the wafers having the poly layer to be etched in a decapping solution, such as a hydrofluoric acid (HF) bath, prior to placing the wafers in a poly etch bath. However, the wafers must be washed in deionized water (DI water) and dried prior to going into the poly etch bath, and such a washing procedure may cause sufficient native oxide to regrow to again inhibit the initiation of the poly etch. Further, the variations in the amount of time that pass between the end of the decap process and the beginning of the poly etch may again result in lot to lot variations in the amount of poly etched. Yet further, the need to have two different wet chemical baths and the increase in production time and cost make this solution less than optimal. There may also be an operator safety issue in having an acid bath in the same general vicinity as the typically caustic poly etch bath, since acids and bases should not be mixed without safety precautions.
SUMMARY
[0006] The above-mentioned issues are addressed by the present invention and will be understood by reading and studying the following specification. A method of etching a polysilicon layer consists essentially of adding a spike of an ammonium hydroxide solution to a bath of tetra methyl ammonium hydroxide (TMAH) solution, and then immersing the substrate with the polysilicon layer in the solution. In an embodiment, the substrate is immersed in the ammonium hydroxide and TMAH solution within one hour of when the ammonium hydroxide spike was added. The substrate is removed after the preselected etch time period, and the substrate is washed to remove the ammonium hydroxide and TMAH etching solution from the substrate, and the substrate is dried. The ammonium hydroxide and TMAH solution provides a rapid decap and polysilicon etch rate in a temperature range of approximately 60° C. to 90° C. It is possible to increase the etch rate by use of a pressure cooker type arrangement that allows the temperature of the TMAH to be raised to above the boiling point of the solution. The etch process may also be preformed on a spin vacuum chuck with either pressure spray dispense nozzles, carrier gas mist dispense nozzles, or with low pressure stream flow dispense nozzles. The TMAH concentration has a broad manufacturing tolerance and may vary between 2.5% and 25% in deionized (DI) water, but a preferred concentration is 12.5% to account for both dilution due to repeated spikes of ammonium hydroxide solution, and to account for evaporation during the course of the life of the etch bath. One method of controlling the life of the etch bath is to maintain the pH of the solution at a greater value than 13. The ammonium hydroxide solution used as the spike concentration is preferably approximately 35% in water, and the volume of the spike may vary from as low as 0.2% to as much as 2% of the total volume of the etch bath.
[0007] The decapping etch rate of the native silicon oxide layer on the top surface of the polysilicon layer may be greater than 800 Angstroms per minute. The etch rate of the polysilicon layer is approximately 4000 Angstroms per minute with the etch rate of the underlying oxide layer less than 20 Angstroms per minute.
[0008] These and other aspects, embodiments, advantages, and features will become apparent from the following description and the referenced drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates an embodiment of an etch system;
[0010] FIG. 2 illustrates an embodiment of a tank etch system;
[0011] FIG. 3A illustrates a possible flow diagram for an embodiments of the etch method of FIG. 1 ;
[0012] FIG. 3B illustrates a possible flow diagram for an embodiments of the etch method of FIG. 2 ;
[0013] FIG. 4A shows an embodiment of a contact in a dielectric layer having a layer of polysilicon with a patterned photoresist layer;
[0014] FIG. 4B shows the embodiment of FIG. 4A after etching in accordance with the invention, showing a contact in a dielectric layer having patterned polysilicon conductors;
[0015] FIG. 5 is a simplified diagram for an embodiment of a controller coupled to an electronic device; and
[0016] FIG. 6 illustrates a diagram for an embodiment of an electronic system having devices.
DETAILED DESCRIPTION
[0017] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific aspects and embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
[0018] The terms wafer and substrate used in the following description include any structure having an exposed surface with which to form an integrated circuit (IC) structure or a micro electro-mechanical (MEM) structure. The term substrate is understood to include semiconductor wafers. The term substrate is also used to refer to semiconductor structures during processing, and may include other layers that have been fabricated thereupon. Both wafer and substrate include doped and undoped semiconductors, epitaxial semiconductor layers supported by a base semiconductor or insulator, as well as other semiconductor structures well known to one skilled in the art. The term conductor is understood to generally include n-type and p-type semiconductors and the term insulator or dielectric is defined to include any material that is less electrically conductive than the materials referred to as conductors or as semiconductors.
[0019] The term “horizontal” as used in this application is defined as a plane parallel to the conventional plane or surface of a wafer or substrate, regardless of the orientation of the wafer or substrate. The term “vertical” refers to a direction perpendicular to the horizontal as defined above. Prepositions, such as “on”, “side” (as in “sidewall”), “higher”, “lower”, “over” and “under” are defined with respect to the conventional plane or surface being on the top surface of the wafer or substrate, regardless of the orientation of the wafer or substrate. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
[0020] FIG. 1 shows an embodiment of an illustrative spin spray etch polysilicon (poly) etch. A spin spray system 100 has a vacuum spin assembly 102 having a vacuum pump and spin motor assembly 104 , connected via a valve and shaft 106 to a vacuum substrate holder (chuck) 108 , using the vacuum pressure to hold substrate 110 , which may illustratively be silicon. The substrate 110 is placed on the chuck 108 , and the vacuum valve 106 opens to provide vacuum pressure from the vacuum pump 104 to hold the substrate 110 on the spin chuck 108 .
[0021] The wafer 110 either remains stationary, or spins at a predetermined speed or program of spin speeds, while an etch mixture is dispensed from dispense fixture 112 , illustratively shown as a shower head drip system. The subject matter is not so limited, and the fixture 112 may be a simple open tube nozzle, a high pressure atomizer (using purge gas 114 to break the etchant into tiny droplets), a linear array of drip nozzles, or other liquid dispense methods. The dispense fixture 112 receives materials such as a purge gas 114 through control valve 116 , or deionized water (DI water) 118 through valve 120 , or tetra methyl ammonium hydroxide (TMAH) 122 through valve 124 , or ammonium hydroxide 126 through valve 128 , or mixtures thereof, via pipe 130 .
[0022] The etchants may be stored and dispensed in their final solution concentrations, or they may be mixed in pipe 130 . As an illustrative example, the TMAH 122 may be in the form of 100% TMAH and the valve 124 may be opened sufficiently to provide a 10% mixture of TMAH mixed with 90% DI water 118 through valve 120 . Alternatively, the TMAH 122 may be stored in the form of a 10% solution and dispensed through valve 124 directly through pipe 130 and dispense fixture 112 onto the substrate 110 without any mixing with any of the other stored materials 114 , 118 or 126 .
[0023] In an embodiment, the TMAH is provided as a 12.5% solution in DI water, and is mixed with 35% ammonium hydroxide during an initial decap etch stage prior to the main poly etch cycle. The TMAH storage 122 has a thermocouple and heater element to maintain a TMAH temperature of 90° C. The substrate 110 may be spun slowly during the initial oxide decap etch, or it may be held stationary in a puddle etch.
[0024] FIG. 2 illustrates an embodiment of an illustrative tank poly etch system 200 . A hot plate 202 containing a thermocouple or other temperature controlling device maintains the tank 204 and the etch solution 206 in the tank at a predetermined temperature, in an embodiment 90° C. The etch solution has a surface 208 with etch substrates 210 immersed below the level of the surface 208 . Prior to immersing the substrates 210 , or simultaneous to immersing the substrates, or after a predetermined time period has elapsed since the last time an ammonium hydroxide spike was added to the solution 206 , in an embodiment one hour, a fixed volume of ammonium hydroxide 212 is added to the etch solution 206 , in an embodiment 1% of the volume of the etch solution 206 . In an embodiment, the pH of the solution 206 is maintained above a value of 13. The level of the etch solution 206 should always be high enough to cover all of the substrates 210 .
[0025] FIG. 3A illustrates a flow chart of steps for a spin etch 300 using the apparatus shown in FIG. 1 . At 302 a substrate is placed on the vacuum chuck, and then an oxide decap etch using a mixture of ammonium hydroxide and TMAH at a temperature of 90° C. occurs at 304 , while the substrate remains stationary. After a fixed time period the ammonium hydroxide solution is turned off and the TMAH solution continues to flow, while the substrate slowly spins to agitate the etch solution and replace depleted portions of the etch solution at 306 . This continues for a predetermined time period, when the TMAH solution is turned off and the DI water rinse solution is turned on at 308 . The substrate continues to spin while the DI water rinse is progressing, until a predetermined time period expires, and the DI water is turned off. At 310 the substrate spins at a higher speed to dry the substrate, and the purge gas (typically nitrogen) may be turned on to blow dry the substrate. At 312 the substrate is removed from the chuck, typically by automated handling equipment, and moved to further substrate processing 314 , such as photoresist removal, or dielectric deposition, or various memory or MEM fabrication steps.
[0026] FIG. 3B illustrates a flow chart for a tank etch 320 using the apparatus of FIG. 2 . At 322 the temperature of a TMAH bath is measured and maintained at a predetermined temperature, in an embodiment 90° C. A measured small amount of ammonium hydroxide solution, in an embodiment 1% of the etch solution volume, is added to the hot TMAH at 324 , a process that may be known as spiking. At least one substrate containing a poly layer to be etched, typically patterned photo-resist coated wafers, are immersed in the bath at 326 , and left to etch for a predetermined time period. In an embodiment the etch rate of poly is about 4,000 Å/minute. At 328 the substrates are removed from the etch bath and rinsed in DI water, or other washing procedures, and then dried at 330 . Spin drying or blow drying may typically be used. Alternatively, the imaged photo resist layer may be removed prior to drying the wafer, or even prior to washing the wafer. At 332 the substrate is moved to further substrate processing, such as photoresist removal, or dielectric deposition, or various memory or MEM fabrication steps.
[0027] FIG. 4A illustrates a semiconductor device 400 prior to decap and poly etch in accordance with the present invention. A substrate 402 , illustratively a semiconductor wafer, has a diffused region 404 , covered by a dielectric layer, such as silicon oxide layer 406 . The dielectric layer 406 has a hole, or contact recess 408 formed through the dielectric 406 to contact the diffused region 404 . A deposited layer of conductive TiN 410 covers the flat portion of the contact recess 408 . A layer of polysilicon 420 , which may be either doped or undoped, overlays the dielectric 406 , and fills the contact recess 408 .
[0028] The polysilicon layer 420 may have what may be known as a native oxide layer 424 that may form in varying thicknesses due to exposure of the polysilicon layer 420 to the oxygen or moisture in the air during the time period after the polysilicon deposition, during the patterning process, and before the poly etch process. Removing this native oxide, also known as an oxide cap, may be known as a decapping process. A patterned photoresist layer 422 is formed on those portions of the polysilicon layer 420 that are desired to remain after the poly etch process.
[0029] FIG. 4B illustrates the semiconductor device 400 after decap and poly etch in accordance with the present invention. There are etched poly lines shown going into the plane of the figure, and the photoresist layer has been removed to better show the finished poly lines. There may be a remaining cap oxide layer on the tops of the etched poly lines 412 or 414 , or the photoresist removal process may strip off the cap oxide along with the photoresist. Any possible remaining oxide cap is not shown in this figure, but whether or not the cap oxide still exists does not affect the device or the processing of the device.
[0030] A number of patterned and etched poly lines are shown with an orientation that is into and out of the plane of the figure. The poly lines such as 412 may be used to make an electrical contact to the diffused region 404 through the TiN layer 410 , and may also make contact with an overlaying layer of metal, such as aluminum. The TiN layer may be used in the contact recess 408 to prevent aluminum to silicon alloy spikes, or to prevent impurity contamination from reaching the sensitive electrical region at the diffusion to substrate boundary. Since the poly line 412 may be unintentionally (or intentionally) not completely covering the bottom of the contact recess 408 , it may be important to have a poly etch process that has a large poly to TiN etch ratio, so that the TiN may act as an etch stop. In a similar fashion, the poly lines 414 on the top of the dielectric layer 406 should have a etch process that has a large poly to oxide etch ratio, so as to not unnecessarily thin the protective dielectric layer 406 .
[0031] Structures such as shown in FIG. 4 may be used in any integrated circuit or transistor devices, such as flash memory devices as well as other memory, logic or information handling devices and systems. Embodiments of these information handling devices include wireless systems, telecommunication systems, computers and integrated circuits.
[0032] FIG. 5 illustrates a diagram for an electronic system 500 having one or more devices having etched poly layers formed according to various embodiments of the present invention. Electronic system 500 includes a controller 502 , a bus 504 , and an electronic device 506 , where bus 504 provides electrical conductivity between controller 502 and electronic device 506 . In various embodiments, controller 502 and/or electronic device 506 include an embodiment for a conductive TiN layer in the contact recesses, and etched polysilicon lines as previously discussed herein. Electronic system 500 may include, but is not limited to, information handling devices, wireless systems, telecommunication systems, fiber optic systems, electro-optic systems, and computers.
[0033] FIG. 6 depicts a diagram of an embodiment of a system 600 having a controller 602 and a memory 606 . Controller 602 and/or memory 606 include an etched conductive poly layer as described herein. System 600 also includes an electronic apparatus 608 , and a bus 604 , where bus 604 may provide electrical conductivity and data transmission between controller 602 and electronic apparatus 608 , and between controller 602 and memory 606 . Bus 604 may include an address, a data bus, and a control bus, each independently configured. Bus 604 also uses common conductive lines for providing address, data, and/or control, the use of which may be regulated by controller 602 . In an embodiment, electronic apparatus 608 includes additional memory devices configured similarly to memory 606 . An embodiment includes an additional peripheral device or devices 610 coupled to bus 604 . In an embodiment controller 602 is a processor. Any of controller 602 , memory 606 , bus 604 , electronic apparatus 608 , and peripheral device or devices 610 may include a signal conductor layer having an etched poly layer in accordance with the disclosed embodiments. System 600 may include, but is not limited to, information handling and telecommunication systems, and computers. Peripheral devices 610 may include displays, additional storage memory, or other control devices that may operate in conjunction with controller 602 and/or memory 606 .
[0034] The use of an integrated decapping and polysilicon etch in a single etch bath has cost and time of manufacture benefits over etch systems that use separate etch baths for the decap etch versus the poly etch. Typically, a dilute hydrofluoric acid (HF) is used to remove the cap oxide, since HF solutions may be buffered to provide an etch rate that is consistent over a fairly long time period. After the HF decapping etch, the substrates must be washed and dried because of safety concerns with acids in general, and that acids and basic solutions such as TMAH have exothermic reactions when mixed. Thus, the poly etch process requires two different and typically incompatible etch baths that should not be located near each other due to safety concerns. This increases the cost and the amount of fabrication area needed for the etch process, and causes increased safety concern and chemical disposal problems. In addition, the time to etch the poly has increased, which also increases manufacturing cost.
[0035] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of embodiments of the present invention, including TiN layers with graded compositions. It is to be understood that the above description is intended to be illustrative, and not restrictive, and that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Combinations of the above embodiments and other embodiments will be apparent to those of skill in the art upon studying the above description. The scope of the present invention includes any other applications in which embodiments of the above structures and fabrication methods are used. The scope of the embodiments of the present invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
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The use of an ammonium hydroxide spike to a hot tetra methyl ammonium hydroxide (TMAH) solution to form an insitu poly oxide decapping step in a polysilicon (poly) etch process, results in a single step rapid poly etch process having uniform etch initiation and a high etch selectivity, that may be used in manufacturing a variety of electronic devices such as integrated circuits (ICs) and micro electro-mechanical (MEM) devices. The etching solution is formed by adding 35% ammonium hydroxide solution to a hot 12.5% TMAH solution at about 70° C. at a rate of 1% by volume, every hour. Such an etch solution and method provides a simple, inexpensive, single step self initiating poly etch that has etch stop ratios of over 200 to 1 over underlying insulator layers and TiN layers.
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FIELD
The present disclosure relates to hydraulic control systems and more particularly to hydraulic control systems and their components for dual clutch transmissions.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
In automotive transmission art, the dual clutch transmission (DCT) is a relatively new concept. A typical dual clutch transmission configuration includes a pair of mutually exclusively operating input clutches which drive a pair of input shafts. The input shafts may be disposed on opposite sides of an output shaft or may be disposed concentrically between spaced-apart output shafts. One of each of a plurality of pairs of constantly meshing gears which provide the various forward and reverse gear ratios is freely rotatably disposed on one of the shafts and the other of each pair of gears is coupled to one of the other shafts. A plurality of synchronizer clutches selectively couple the freely rotatable gears to the associated shaft to achieve forward and reverse gear ratios. After the synchronizer clutch is engaged, the input clutch associated with the input shaft having the engaged synchronizer clutch is applied to transmit power through the transmission. Reverse gear is similarly achieved except that it includes an additional (idler) gear to provide torque reversal.
Dual clutch transmissions are known for their sporty, performance oriented operating characteristics which mimic those of a conventional (manual) transmission. They also typically exhibit good fuel economy due to their good gear mesh efficiency, ratio selection flexibility, reduced clutch losses and the lack of a torque converter.
There are several design considerations unique to dual clutch transmissions, for example, the input clutches must be of relatively large size because of heat generated during clutch slip. Furthermore, such heat generation typically requires correspondingly larger and more complex cooling components capable of dissipating relatively large quantities of heat. Finally, because such transmissions typically have many sets of axially aligned, meshing gears, their overall length may limit their use to certain vehicle designs.
Control of the input clutches and selection and engagement of a particular gear by translation of a synchronizer and associated positive clutch is typically achieved by a hydraulic control system. Such a system, itself under the control of an electronic transmission control module (TCM), includes hydraulic valves and actuators which engage the synchronizers and gear clutches. Optimum operating efficiency and thus fuel efficiency and minimal heat generation can be achieved by designing such hydraulic control systems to exhibit low leakage and positive control characteristics. The present invention is so directed.
SUMMARY
The present invention comprehends two embodiments of a hydraulic control system for a dual clutch transmission having three countershafts, a third, idler shaft and five shift rails and hydraulic actuators. The hydraulic control systems include a regulated source of pressurized hydraulic fluid including a pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.
The embodiments incorporate two essentially independent control systems supplied with hydraulic fluid through two independently operating valves. The two independent control systems are associated with the input clutch operators and the gear shift logic valves and actuators. When the transmission is operating in a normal ascending or descending gear selection sequence, this configuration permits pre-staging or pre-selection of a gear associated with one countershaft while a gear associated with the other countershaft is engaged and transmitting torque. Furthermore, if a component or components associated with one countershaft fail, the other countershaft and the alternating (i.e., first, third, fifth) selection of gear ratios it provides will still be fully operational—a highly desirable failure mode.
The hydraulic control systems according to the present invention are less complex and expensive relative to competing systems, provide improved control through interconnected logic valves which reduce the likelihood of engaging a wrong or multiple gears and provide reduced energy consumption by allowing shut-down of portions of the control system during steady state operation. Certain embodiments of the control system utilize pairs of pressure or flow control valves to control pressure on both sides of shift actuator pistons which provides better control and improved shifts.
Thus it is an object of the present invention to provide a hydraulic control system for a dual clutch automatic transmission.
It is a further object of the present invention to provide a hydraulic control system for a dual clutch transmission having a plurality of spool or logic valves and hydraulic actuators.
It is a still further object of the present invention to provide a hydraulic control system for a dual clutch transmission having a plurality of two position solenoid valves (on-offs), spool valves and hydraulic actuators.
It is a still further object of the present invention to provide a hydraulic control system for a dual clutch transmission having a plurality of flow or pressure control valves, two position solenoid valves, logic or spool valves and hydraulic actuators.
It is a still further object of the present invention to provide a hydraulic control system for a dual clutch transmission comprising two essentially independent hydraulic systems, one associated with clutch operation and the other associated with gear selection.
It is a still further object of the present invention to provide a hydraulic control system for a dual clutch transmission having a pair of input clutches associated with a pair of concentric input shafts and a pair of countershafts.
Further objects, advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1 is a pictorial view of an exemplary dual clutch automatic transmission with portions broken away incorporating a hydraulic control system according to the present invention having five shift actuator assemblies;
FIGS. 2A , 2 B and 2 C are schematic flow diagrams of a first embodiment of a hydraulic control system according to the present invention for a dual clutch automatic transmission; and
FIGS. 3A , 3 B and 3 C are schematic flow diagrams of a second embodiment of a hydraulic control system according to the present invention for a dual clutch automatic transmission.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
With reference to FIG. 1 , an exemplary dual clutch automatic transmission incorporating the present invention is illustrated and generally designated by the reference number 60 . The dual clutch transmission 60 includes a typically cast, metal housing 12 which encloses and protects the various components of the transmission 60 . The housing 12 includes a variety of apertures, passageways, shoulders and flanges (not illustrated) which position and support the components of the transmission 60 . The transmission 60 includes an input shaft 14 which receives motive power from a prime mover (not illustrated) such as an internal combustion gas or Diesel engine or a hybrid or electric power plant and a single or double output shaft 16 which drives a final drive assembly 18 which may include a propshaft, a differential and drive axles. The input shaft 14 is coupled to and drives a clutch housing 62 . The clutch housing 62 , in turn, drives a pair of concentrically disposed dry input clutches, a first input clutch 64 A and a second input clutch 64 B which are mutually exclusively engaged to provide drive torque to a respective pair of concentric input members, a first or inner input shaft 66 A and a second or outer hollow input shaft or quill 66 B.
Secured to and rotating with each of the input members 66 A and 66 B are a plurality of helical or spur gears (not illustrated) which are in constant mesh with helical or spur gears which are freely rotatably disposed on a first layshaft or countershaft 68 A and a parallel, second layshaft or countershaft 68 B. Adjacent and parallel to the second countershaft is a third layshaft or countershaft 68 C. A first drive gear meshes with a first driven gear 70 A on the first countershaft 68 A. A second drive gear meshes with a second driven gear 72 A on the first countershaft 68 A. A third drive gear meshes with a third driven gear 74 A on the first countershaft 68 A. A fourth drive gear meshes with a fourth driven gear 76 A on the first countershaft 68 A. A fifth driven gear 70 B on the second countershaft 68 B meshes with a fifth drive gear 70 C on the third countershaft 68 C. The second drive gear also meshes with a sixth driven gear 72 B on the second countershaft 68 B which meshes with a seventh driven gear 72 C on the third countershaft 68 C. An eighth drive gear meshes with an eighth driven gear 74 B on the second countershaft 68 B.
Disposed either adjacent certain single gears or between adjacent pairs of gears on the countershafts 68 A, 68 B and 68 C are synchronizer clutch assemblies. Each synchronizer clutch assembly, in accordance with conventional practice, includes a synchronizer assembly which, when activated, synchronizes the speed of a gear to that of the associated countershaft and a positive clutch, such as a dog or face clutch, which positively connects the gear to the shaft. Thus, between the driven gears 70 A and 72 A on the first countershaft 68 A is a first shift actuator and synchronizer clutch assembly 80 A having a double, i.e., back-to-back, first synchronizer clutch 82 A which selectively and exclusively synchronizes and engages one of the gears 70 A and 72 A to the first countershaft 68 A. The first synchronizer clutch 82 A is bi-directionally translated by a first shift rail and fork assembly 84 A which, in turn, is translated by a first shift actuator assembly 86 A. The real time position of the first synchronizer clutch 82 A and the first shift rail and fork assembly 84 A is sensed by a first linear position sensor 88 A which preferably provides a continuous, i.e., proportional, output signal to a transmission control module TCM indicating the position of the first synchronizer clutch 82 A.
Between the fifth driven gear 70 B and the sixth driven gear 72 B on the second countershaft 68 B is a second shift actuator and synchronizer clutch assembly 80 B having a single synchronizer clutch 82 B which synchronizes and couples the driven gears 70 B and 72 B together. The second synchronizer clutch 82 B is bi-directionally translated by a second shift rail and fork assembly 84 B which, in turn, is translated by a second shift actuator assembly 86 B. The real time position of the second synchronizer clutch 82 B and the second shift rail and fork assembly 84 B is sensed by a second linear position sensor 88 B which preferably provides a continuous, i.e., proportional, output signal to the transmission control module TCM indicating the position of the second synchronizer clutch 82 B.
Between the driven gears 74 A and 76 A on the first countershaft 68 A is a third shift actuator and synchronizer clutch assembly 90 A having a double, i.e., back-to-back, third synchronizer clutch 92 A which selectively and exclusively synchronizes and engages one of the gears 74 A and 76 A to the first countershaft 68 A. The third synchronizer clutch 92 A is bi-directionally translated by a third shift rail and fork assembly 94 A which, in turn, is translated by a third shift actuator assembly 96 A. The real time position of the third synchronizer clutch 92 A and the third shift rail and fork assembly 94 A is sensed by a third linear position sensor 98 A which preferably provides a continuous, i.e., proportional, output signal to the transmission control module TCM indicating the position of the third synchronizer clutch 92 A.
Adjacent the eighth driven gear 74 B on the second countershaft 68 B is a fourth shift actuator and synchronizer clutch assembly 90 B having a single synchronizer clutch 92 B which synchronizes and couples the eighth driven gear 74 B to the second countershaft 68 B. The fourth synchronizer clutch 92 B is bi-directionally translated by a fourth shift rail and fork assembly 94 B which, in turn, is translated by a fourth shift actuator assembly 96 B. The real time position of the fourth synchronizer clutch 92 B and the fourth shift rail and fork assembly 94 B is sensed by a fourth linear position sensor 98 B which preferably provides a continuous, i.e., proportional, output signal to the transmission control module TCM indicating the position of the fourth synchronizer clutch 92 B.
Finally, between the fifth drive gear 70 C and the seventh driven gear 72 C on the third countershaft 68 C is a fifth shift actuator and synchronizer clutch assembly 90 C having a double, i.e., back-to-back, synchronizer clutch 92 C which selectively and exclusively synchronizes and engages one of the gears 72 C to the third countershaft 68 C or couples the driven gear 72 C to the drive gear 70 C. The fifth synchronizer clutch 92 C is bi-directionally translated by a fifth shift rail and fork assembly 94 C which, in turn, is translated by a fifth shift actuator assembly 96 C. The real time position of the fifth synchronizer clutch 92 C and the fifth shift rail and fork assembly 94 C is sensed by a fifth linear position sensor 98 C which preferably provides a continuous, i.e., proportional, output signal to the transmission control module TCM indicating the position of the fifth synchronizer clutch 92 C. It should be appreciated that the linear position sensors 88 A, 88 B, 98 A, 98 B and 98 C may be replaced with other sensors such as two or three position switches or open loop control with system characterization.
Additionally, a detent mechanism may be employed with each of the shift assemblies to assist obtaining and maintaining a gear or speed ratio once it is selected and to assist obtaining and maintaining the synchronizer clutch in neutral, i.e., an unengaged position. Thus, a first detent assembly 89 A may be operatively associated with the first shift actuator and synchronizer clutch assembly 80 A. A second detent assembly 89 B may be operatively associated with the second shift actuator and synchronizer clutch assembly 80 B. A third detent assembly 99 A may be operatively associated with the third shift actuator and synchronizer clutch assembly 90 A. A fourth detent assembly 99 B may be operatively associated with the fourth shift actuator and synchronizer clutch assembly 90 B and a fifth detent assembly 99 C may be operatively associated with the fifth shift actuator and synchronizer clutch assembly 90 C.
It will be appreciated that the transmission 60 illustrated and described above is laid out with four forward gears on one countershaft and the remaining (three) forward gears and reverse on two other countershafts. It is thus capable of providing seven forward speeds and reverse. Similar configurations, all deemed to be within the scope of this invention may, for example, include six forward speeds (or gears) and one or two reverse speeds (or gears) or five forward speeds and one or two reverse speeds.
It should be understood that while the present invention is directed to hydraulic control systems for dual clutch transmissions, such systems are typically controlled by sensor signals and memory, software and one or more microprocessors contained in a transmission control module TCM. Thus, the transmission control module TCM includes a plurality of inputs which receive data from, for example, the linear position sensors, the speed sensors and the pressure sensor, and a plurality of outputs which control and modulate, for example, the positions of the clutches, pressure and flow control valves, logic solenoid valves and shift rails.
Referring now to FIGS. 1 , 2 A, 2 B and 2 C, a first embodiment of a hydraulic control system for the dual clutch automatic transmission 60 described above is illustrated and designated by the reference number 2000 . The hydraulic control system 2000 includes a sump 102 to which hydraulic fluid returns and collects from various components and regions of the automatic transmission 60 . A suction line 104 which may include a filter 106 communicates with the inlet port 108 of an engine driven or electric pump 110 which may be, for example, a gear pump, a vane pump, a gerotor pump or other positive displacement pump. An outlet port 112 of the pump 110 provides hydraulic fluid under pressure in a supply line 114 to a spring biased blow-off safety valve 116 and to a pressure side filter 118 which is disposed in parallel with a spring biased check valve 120 . The safety valve 116 is set at a relatively high predetermined pressure and if the pressure in the supply line 114 exceeds this pressure, the safety valve 116 opens momentarily to relieve and reduce it. If pressure ahead of the filter 118 rises to a predetermined differential pressure, indicating a partial blockage or flow restriction when cold of the filter 118 and the possibility that insufficient hydraulic fluid may be provided in an outlet line 122 to the remainder of the control system 2000 , the check valve 120 opens to allow hydraulic fluid to bypass the filter 118 .
A second check valve 124 , in the outlet line 122 , is configured to maintain hydraulic pressure in a main supply line 126 and to prevent backflow through the pump 110 . The main supply line 126 supplies pressurized hydraulic fluid to an accumulator 130 having a piston 132 and a biasing compression spring 134 . The accumulator 130 may be one of many other designs such as gas charged. The accumulator 130 stores pressurized hydraulic fluid and supplies it to the main supply line 126 , to a main or system pressure sensor 136 and to the other components of the control system 2000 thereby eliminating the need for the engine driven or electric pump 110 to run continuously. The main pressure sensor 136 reads the delivered hydraulic system pressure in real time and provides this data to the transmission control module TCM.
It should be appreciated that the other embodiment of the hydraulic control system according to the present invention preferably includes the same hydraulic supply, filtration and control components just described. Accordingly, these components will be only briefly described in connection with the subsequent figures and embodiment, it being understood that the above description may be referenced to provide details of these components.
The first embodiment 2000 of the hydraulic control system is divided into a clutch operating portion and gear selection portion. As such, the first main supply line 126 A communicates with the inlet port 140 A of a first pressure control solenoid valve 140 . An outlet port 140 B of the first pressure control solenoid valve 140 connects to a supply line 2002 and a first manifold 2004 . The first manifold 2004 has a first branch 2004 A which communicates with an inlet port 154 A of a first electric pressure or flow clutch control solenoid valve 154 . The first clutch control solenoid valve 154 also includes an outlet port 154 B and an exhaust port 154 C which communicates with the sump 102 . The outlet port 154 B provides hydraulic fluid through an orifice 156 to the first clutch piston and cylinder assembly 160 having the cylinder 162 and the piston 164 slidably disposed therein. It should be appreciated that the orifice 156 and other orifices can be added or omitted without departing from the scope of this invention. A check valve 166 is connected between the first piston and cylinder assembly 160 and a second branch 20048 of the first manifold 2004 .
A third branch 2004 C of the first manifold 2004 communicates with an inlet port 204 A of the second electric pressure or flow clutch control solenoid valve 204 . The second clutch control solenoid valve 204 also includes an outlet port 204 B and an exhaust port 204 C which communicates with the sump 102 . The outlet port 204 B of the second clutch control solenoid valve 204 provides hydraulic fluid through an orifice 206 to a second clutch piston and cylinder assembly 210 having a cylinder 212 and a piston 214 slidably disposed therein. A check valve 216 is connected between the second piston and cylinder assembly 210 and a fourth branch 2004 D of the manifold 2004 . It should be noted the check valves 166 and 216 could be eliminated depending upon the system requirements.
The second main supply line 126 B communicates with an inlet port 190 A of a second pressure control solenoid valve 190 . An outlet port 190 B connects to a second manifold 2012 . A first branch 2012 A of the second manifold 2012 communicates with an inlet port 2018 A of a first two position (on-off) solenoid valve 2018 . An outlet port 2018 B of the first two position solenoid valve 2018 communicates with a first inlet port 2020 A of a first spool or logic valve 2020 and an exhaust port 2018 C of the first two position (on-off) solenoid valve 2018 communicates with the sump 102 .
A second branch 2012 B of the second manifold 2012 communicates with an inlet port 2022 A of a first pressure or flow control solenoid valve 2022 . The first pressure or flow control solenoid valve 2022 has an outlet port 2022 B which communicates with a second inlet port 2020 B of the first spool or logic valve 2020 . An exhaust port 2022 C of the first pressure or flow control solenoid valve 2022 communicates with the sump 102 . A third branch 2012 C of the second manifold 2012 communicates with an inlet port 2026 A of a second pressure or flow control solenoid valve 2026 having an outlet port 2026 B which communicates with a third inlet port 2020 C of the first spool or logic valve 2020 . An exhaust port is associated with each of the inlet ports 2020 A, 2020 B and 2020 C which communicates with the sump 102 . An exhaust port 2026 C of the second pressure or flow control solenoid valve 2026 also communicates with the sump 102 .
A fourth branch 2012 D of the second manifold 2012 communicates with an inlet port 2028 A of a second two position solenoid valve 2028 . An outlet port 2028 B of the second two position (on-off) solenoid valve 2028 is connected to a control port 2020 D of the first logic valve 2020 and an exhaust port 2028 C of the second two-position solenoid valve 2028 is connected to the sump 102 . A fifth branch 2012 E of the second manifold 2012 communicates with an inlet port 2032 A of a third two position (on-off) solenoid valve 2032 .
The first spool or logic valve 2020 also includes a first outlet port 2020 E which is connected by a hydraulic line 2036 to a control port 2040 B of a second spool or logic valve 2040 as well as a second port 2050 B of a second piston and cylinder assembly 2050 . A third outlet port 2020 G is connected by a line 2038 to a first inlet port 2040 A of the second logic valve 2040 . The second logic valve 2040 includes a pair of exhaust ports 2040 C and 2040 D and a first outlet port 2040 E that communicates through a line 2042 with a first port 2044 A of a first, preferably dual area piston and cylinder assembly 2044 which translates the first shift rail and fork assembly 84 A. A second port 2044 B at the other end of the first piston and cylinder assembly 2044 communicates with the fifth outlet port 20201 of the first logic valve 2020 through a line 2046 . A second outlet port 2040 F of the second logic valve 2040 communicates through a line 2048 to a first port 2050 A at the other end of the second piston and cylinder assembly 2050 which translates the second shift rail and fork assembly 84 B.
A second outlet port 2020 F of the first logic valve 2020 is connected through a line 2052 to a control port 2054 C of a third spool or logic valve 2054 and a port 2060 B at one end of a third, preferably dual area piston and cylinder assembly 2060 which translates the third shift rail and fork assembly 94 A. The sixth outlet port 2020 J of the first logic valve 2020 is connected through a line 2056 to a first inlet port 2054 A of the third logic valve 2054 which also includes a pair of exhaust ports. A first outlet port 2054 D of the third logic valve 2054 communicates through a line 2062 to a second inlet port 2064 B of a fourth spool or logic valve 2064 . A second outlet port 2054 E communicates through a line 2058 to a port 2060 A at the other end of the third piston and cylinder assembly 2060 . A fourth outlet port 2020 H of the first logic valve 2020 is connected by a line 2066 with a first inlet port 2064 A of the fourth logic valve 2064 . The fourth logic valve 2064 includes a control port 2064 C which is connected by a line 2068 to the outlet port 2032 B of the third two position solenoid valve 2032 .
The fourth logic valve 2064 includes three exhaust ports 2064 D, 2064 E and 2064 F alternating with the inlet ports 2064 A and 2064 B which communicate with the sump 102 and a first outlet port 2064 G which is connected to a port 2070 A one end of a fourth piston and cylinder assembly 2070 by a line 2072 . A port 2070 B at the other end of the fourth piston and cylinder assembly 2070 is connected to a third outlet port 2064 H by a line 2074 . The fourth piston and cylinder assembly 2070 translates the fourth shift rail and fork assembly 94 B. A second outlet port 20641 of the fourth logic valve 2064 is connected by a line 2078 to a port 2080 A at one end of a fifth, preferably dual area piston and cylinder assembly 2080 . A port 2080 B at the other end of the fifth piston and cylinder assembly 2080 is connected by a line 2082 to a fourth outlet port 2064 J of the fourth logic valve 2064 . The fifth piston and cylinder assembly 2080 translates the fifth shift rail and fork assembly 94 C. It will be appreciated that all of the piston and cylinder assemblies 2044 , 2050 , 2060 , 2070 and 2080 may include dual area pistons, if desired, or that such assemblies may include single area pistons with associated feedback and control assemblies or combinations thereof, as illustrated.
Operation of the first embodiment of the hydraulic control system 2000 essentially involves the selection of a desired gear ratio in the transmission 60 by the transmission control module TCM and selection and activation of the pressure control solenoid valves 140 and 190 to independently provide pressurized hydraulic fluid to the input clutch side or the gear shift side of the hydraulic control system 2000 , activation of the pressure or flow control solenoid valves 2022 and 2026 to provide controlled flow and pressure of hydraulic fluid to the logic valves 2020 , 2040 , 2054 and 2064 and activation of the two position solenoid valves 2018 , 2028 and 2032 to position the logic valve spools to direct pressurized hydraulic fluid flow to the correct sides of the piston and cylinder assemblies 2044 , 2050 , 2060 , 2070 and 2080 to translate the shift rails 84 A, 84 B, 94 A, 94 B and 94 C to engage the desired gear. Once this has occurred, the input clutch 64 A or 64 B associated with the countershaft 68 A, 68 B or 68 C of the selected gear is engaged by activation of one of the two piston and cylinder assemblies 160 or 210 .
A convenient example of operation may be presented by describing same with the spools of the logic valves 2020 , 2040 , 2054 and 2064 in the positions illustrated in FIGS. 2B and 2C . Activation of the first pressure or flow control solenoid valve 2022 provides hydraulic fluid to the second inlet port 2020 B of the first logic valve 2020 , through the line 2038 to the second logic valve 2040 and through the line 2042 to one end of the first piston and cylinder assembly 2044 . The first shift rail 84 A will then translate to the right (to the left in FIG. 1 ) and engage, for example, sixth gear. The shift is completed by engaging the appropriate input clutch. If, on the other hand, the second pressure or flow control solenoid valve 2026 is activated, hydraulic fluid flow occurs through the third inlet port 2020 C of the first logic valve 2020 and the line 2046 , either returning the first shift rail 84 A to neutral or moving the shift rail 84 A all the way to the left to the position illustrated in FIG. 2B to engage, for example, second gear. The choice of the center (neutral) or left position is commanded by the transmission control module TCM with linear position information from, for example, the first linear position sensor 88 A illustrated in FIG. 1 . A similar pattern of valve activation and logic valve spool translation provides the seven forward and reverse gears of the transmission 60 . For example, if the second two position solenoid valve 2028 is energized, the spool of the first logic valve 2020 translates to the left in FIG. 2B , shifting its hydraulic fluid outputs to the outlet ports 2020 F, 2020 H and 2020 J and the hydraulic circuitry illustrated in FIG. 2C .
Referring now to FIGS. 1 , 3 A, 3 B and 3 C, a second embodiment of a hydraulic control system according to the present invention is illustrated and generally designated by the reference number 2100 . The second embodiment 2100 of the hydraulic control system, as stated above, includes, in common with the other embodiment, the sump 102 , the pump 110 , the filters 106 and 118 , the accumulator 130 and the other components of the hydraulic fluid supply and thus they will not be further described. It should be noted that the filters 106 and or 118 can be omitted without departing from the scope of this invention.
Additionally, the portion of the second embodiment 2100 associated with independent operation of the two sides or sections of the transmission 60 and associated clutches 64 A and 64 B includes the main supply line 126 which bifurcates into the first main supply line 126 A and the second main supply line 126 B. The first main supply line 126 A communicates with the inlet port 140 A of the first pressure control solenoid valve 140 and the second main supply line 126 B communicates with the inlet port 190 A of the second pressure control solenoid valve 190 . The outlet port 140 B of the first pressure control solenoid valve 140 communicates with a first supply manifold 1002 and the outlet port 190 B of the second pressure control solenoid valve 190 communicates with a second supply manifold 1004 . The exhaust ports 140 C and 190 C communicate with the sump 102 .
Similarly, the second embodiment 2100 includes the components associated with activation of the first clutch 64 A, such as the electric pressure or flow clutch control solenoid valve 154 , which receives hydraulic fluid from a first branch 1002 A of the first supply manifold 1002 , the orifice 156 , the first clutch piston and cylinder assembly 160 and the first clutch pressure limit control valve 166 which communicates with a second branch 1002 B of the first supply manifold 1002 . The second embodiment 2100 also includes the components associated with activation of the second clutch 64 B, such as the second electric pressure or flow clutch control solenoid valve 204 which receives hydraulic fluid from a first branch 1004 A of the second supply manifold 1004 , the orifice 206 , the second clutch piston and cylinder assembly 210 and the second clutch pressure limit control valve 216 which communicates with a second branch 1004 B of the second supply manifold 1004 . It should be noted that the pressure control valves 166 and 216 can be eliminated depending upon the system requirements.
The second embodiment 2100 also includes a two inlet check valve 1510 disposed between and communicating with the first supply manifold 1002 and the second supply manifold 1004 . The first supply manifold 1002 or the second supply manifold 1004 having the higher pressure causes the check ball to close off the lower pressure supply manifold and allow communication between the higher pressure supply manifold and the second, main manifold 2012 . This achieves lower hydraulic fluid consumption rates and permits independent gear and clutch actuator control. However, it should be noted that instead of feeding the main manifold 2012 through the two inlet check valve 1510 , it could be connected to the higher pressure main supply line 126 without loss of functionality.
The portion of the second embodiment 2100 associated with gear selection and engagement is the same as the corresponding portion of the first embodiment 2000 illustrated in FIGS. 2B and 2C . Thus, the second embodiment 2100 also includes the first two position (on-off) solenoid valve 2018 , the first pressure or flow control solenoid valve 2022 , the second pressure or flow control solenoid valve 2026 , the first spool or logic valve 2020 , the second two position (on-off) solenoid valve 2028 , the third two position (on-off) solenoid valve 2032 , the second spool or logic valve 2040 , the third spool or logic valve 2054 and the fourth spool of logic valve 2064 .
Similarly, the first, preferably dual area piston and cylinder assembly 2044 is connected to the first outlet port 2040 E of the second logic valve 2040 by the line 2042 and to the fifth outlet port 20201 of the first logic valve 2020 by the line 2046 ; the second piston and cylinder assembly 2050 is connected to the second outlet port 2040 F of the second logic valve 2040 by the line 2048 and to the control port 2040 B of the second logic valve 2040 by the line 2036 . The third, preferably dual area piston and cylinder assembly 2060 is connected to the second outlet port 2054 E of the third logic valve 2054 by the line 2058 and to the control port 2054 C of the third logic valve 2054 by the line 2052 . The fourth piston and cylinder assembly 2070 is connected to the first outlet port 2064 G of the fourth logic valve 2064 by the line 2072 and the third outlet port 2064 H by the line 2074 . The fifth, preferably dual area piston and cylinder assembly 2080 is connected to the second outlet port 20641 of the fourth logic valve 2064 by the line 2078 and the fourth outlet port 2064 J by the line 2082 .
It will be appreciated that the hydraulic control systems according to the two embodiments of the present invention achieve significant improvements in reduced energy consumption and shift performance not only because of the incorporation of the dedicated pump and accumulator but also because of the use of pressure and flow control solenoid valves which allow the majority of the hydraulic system components to be turned off in normal, steady-state, operation. It should also be appreciated that slight variations in logic valve connections and alternate piston and shift rail connections are possible in order to adapt to different five actuator transmissions.
Additionally, these solenoid valves and the linear position sensors on each piston and cylinder shift actuator assembly which provide real time data to the transmission control module regarding the instantaneous positions of the actuators, shift rails and clutches, achieve gear selection and clutch operation that is rapid, positive and efficient without overshoot and wasted energy.
Similarly, the configurations of the two embodiments and the position feedback provided by the linear position sensors permits and facilitates rapid gear sequencing and improved, i.e., reduced, shift times.
Finally, the separation of hydraulic fluid supply and control functions into two regions or sections relating to the input clutches and the gear selection components, allows precise and independent control of engagement and operating pressures of the clutches and shift actuators.
The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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Hydraulic control systems for a dual clutch transmission include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.
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BACKGROUND OF THE INVENTION
During the past decade, many efforts have been made to minimize the amount of volatile materials that escape into the atmosphere when an ink or coating composition has been applied to a substrate. Many compositions have been prepared in which the undesirable volatile solvent is decreased or completely eliminated. One of the problems associated with this approach has been an increase in the viscosity of the ink or coating presenting problems in its handling and application. It is therefore desirable to produce compositions having the proper viscosity. It is also desirable to produce compositions which can be cured rapidly with a minimal consumption of energy. To effect this goal recent improvements in the coatings and ink field have led to compositions which can be cured by radiation means or with a minimal amount of heat energy. Illustrative are compositions and procedures as are described in U.S. Pat. No. 3,700,643 and U.S. Pat. No. 3,759,807.
The use of alkylcarbamoyl alkyl acrylates in coating and ink compositions have been found to impart to them many desirable properties. These alkylcarbamoyl alkyl acrylates are known and have been disclosed in U.S. Pat. No. 3,479,328 and U.S. Pat. No. 3,674,838.
SUMMARY OF THE INVENTION
The present invention provides coating and ink compositions that are essentially free of volatile solvents and which can be cured to the dry state by any of the known radiation and thermal processes.
The compositions of this invention comprise a mixture of (a) at least one monofunctional acrylateurethane or alkylcarbamoyl alkyl acrylate, (b) at least one polyfunctional acrylate-urethane and, optionally, (c) at least one polyfunctional acrylate crosslinker and/or (d) at least one monofunctional acrylate as these are hereinafter defined.
When the coating or ink composition is to be cured by thermal means a free radical initiator is also desirably present; when cure is by light radiation, such as ultraviolet radiation, the presence of a photoinitiator or photosensitizer is desirable; and when the composition is to be cured by electron radiation procedures the presence of such materials is not necessary; though one can, if desired, include a free radical initiator. While the compositions are essentially free of solvents one can, if desired, include a small amount thereof.
DESCRIPTION OF THE INVENTION
As previously indicated, the coating and ink compositions of this invention must contain at least two essential components, the monofunctional acrylate-urethane and the polyfunctional acrylate-urethane, and they can also optionally contain other indicated materials. These compositions can be readily applied to a substrate by any of the known application means and can then be cured to a dry, tack-free state by any of the known curing means. The methods of application or cure are not the subject of this invention and any of the known methods can be used. In fact, these procedures are so numerous and so well known that a detailed explanation thereof is considered unnecessary. Thus, they can be applied by printing equipment, roll coating, dip coating, spraying, brushing, knife coater, curtain coater, or any other method depending upon the equipment available and the ultimate goal of the user. The method for cure can also vary and one can use an electron beam, ultraviolet light or thermal cure. Cure can be carried out under normal atmospheric conditions or under an inert gas atmosphere. As is known to those skilled in the art the amount of time required for cure will vary depending upon the curing method used, the thickness of the film, the particular reactants present and other variables that may be introduced into the composition or the process. Those skilled in the art can readily adjust the conditions to obtain a satisfactory end product.
The substrates that can be coated or printed with the compositions of this invention can be any organic or inorganic, natural or synthetic material. Thus, they can be applied to paper, cloth, wood, metal, fibers, woven or nonwoven, plastic films and sheets, for example, vinyl tiles, vinyl-asbestos tiles, or to simulated woods, such as grain-printed particleboard or chipboard, or printed or decorated surfaces.
For simplicity, the term acrylate as used in this application shall include all of the organic esters of acrylic acid and the organic esters of methacrylic acid, whether aliphatic or aromatic and whether or not substituted with other groups such as halogen, cyano, hydroxyl, t-amino, or any other group which would not interfere with the cure or have an unduly deleterious effect on the finished coating.
The monofunctional acrylate-urethane or alkylcarbamoyl alkyl acrylate useful in the compositions of this invention are those represented by the formula: ##STR1##wherein Z is hydrogen or methyl; X is a linear or branched divalent alkylene of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, cycloalkylene of 5 to 12 carbon atoms, preferably 6 to 8 carbon atoms, or arylene of 6 to 12 carbon atoms; and R is a linear or branched alkyl of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, preferably 6 to 8 carbon atoms, or aryl of 6 to 12 carbon atoms. The X and R groups can be unsubstituted or substituted. Illustrative thereof one can mention 2(N-methylcarbamoyl) ethyl acrylate, 2(N-butyl-carbamoyl) ethyl acrylate, 2 (or 3)(N-methylcarbamoyl) butyl acrylate, 2(N-phenylcarbamoyl)ethyl acrylate, 2(N-methylcarbamoyl)-propylacrylate, 2(N-cyclohexylcarbamoyl)ethyl acrylate, p(N -methylcarbamoyl)phenyl acrylate, 3(N-methylcarbamoyl)-cyclohexyl acrylate, and the like; as well as the methacrylates thereof. The preferred monofunctional acrylateurethanes are 2(N-methylcarbamoyl)ethylacrylate and 2(N-methylcarbamoyl)propyl acrylate.
The monofunctional acrylate-urethane is present in the coating or ink composition at a concentration of from about 1 to 80 weight percent; the preferred concentration for an ink composition is from about 1 to 15 weight percent and for a coating composition it is from about 20 to 50 weight percent.
The polyfunctional acrylate-urethane present in the ink or coating composition can be a polycaprolactone-polyurethane-polyacrylate oligomer or a diurethanediacrylate or a urea-urethane-polyacrylate oligomer. The preferred polycaprolactone-polyurethane-polyacrylate oligomers are the polycaprolactone-diurethane-diacrylate oligomers.
The polycaprolactone-polyurethane-polyacrylates are those compounds disclosed in U.S. Pat. No. 3,700,643, the disclosure of which is incorporated herein by reference. They are the reactions of a polycaprolactone polyol, an organic polyisocyanate and a hydroxyl substituted organic ester of acrylic acid or methacrylic acid, which ester can be aliphatic, cycloaliphatic or aromatic. The hydroxyl substituted esters are the same as those hereinafter defined. Among the suitable organic polyisocyanates are those hereinafter defined. The polycaprolactone polyols are known compounds and they can be diols, triols, tetrols or of higher hydroxyl functionality. The preferred are the diols and triols. Many polycaprolactone polyols are commercially available and are fully disclosed in U.S. Pat. No. 3,169,945.
As described therein the caprolactone polyols are produced by the catalytic polymerization of an excess of the caprolactone compound with an organic functional initiator having at least one reactive hydrogen atom; the polyols can be single compounds or mixtures of compounds, either can be used in this invention. The method for producing the caprolactone polyols is of no consequence. The organic functional initiators can be any hydroxyl compound, as shown in U.S. Pat. No. 3,169,945, and include diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, polyethylene glycol, polypropylene glycol, poly(oxyethylene-oxypropylene) glycols and similar polyalkylene glycols, either block, capped or heteric, containing up to about 40 or more alkyleneoxy units in the molecule, 3-methyl-1,5-pentanediol, cyclohexanediol, 4,4'-methylene-biscyclohexanol, 4,4'-isopropylidenebiscyclohexanol, xylendiol, 2-(4-hydroxymethylphenyl)-ethanol, and the like; triols such as glycerol, trimethylolpropane, 1,4-butanediol, 1,2,6-hexanetriol, triethanolamine, triisopropanolamine, and the like; tetrols such as erythritrol, pentaerythritol, N,N,N',N'-tetrakis-(2-hydroxyethyl)ethylenediamine, and the like.
When the organic functional initiator is reacted with the caprolactone a reaction occurs that can be represented in its simplest form by the equation: ##STR2## In this equation the organic functional initiator is the R"--(OH) x compound and the caprolactone is the ##STR3## compound; this can be caprolactone itself or a substituted caprolactone wherein R' is an alkyl, alkoxy, aryl, cycloalkyl, alkaryl or aralkyl group having up to twelve carbon atoms and wherein at least six of the R' groups are hydrogen atoms, as shown in U.S. Pat. No. 3,169,945. The polycaprolactone polyols that are used are shown by the formula on the right hand side of the equation; they can have a molecular weight of from 130 to about 20,000. The preferred caprolactone polyol compounds are those having a molecular weight of from about 175 to about 2,000. The most preferred are the polycaprolactone diol compounds having a molecular weight of from about 175 to about 500 and the polycaprolactone triol compounds having a molecular weight of from about 350 to about 1,000; these are most preferred because of their low viscosity properties. In the formula m is an integer representing the average number of repeating units needed to produce the compound having said molecular weights.
The diurethane-diacrylates are the reaction products of two moles of a hydroxy/substituted organic ester of acrylic acid or methacrylic acid with one mole of a diisocyanate. The hydroxy/substituted esters that are used are those represented by the formula: ##STR4## wherein Z and X are as herebefore defined. Illustrative thereof one can mention 2-hydroxyethyl acrylate, 2 (or 1)-hydroxypropyl acrylate, 2 (or 1)-hydroxybutyl acrylate, p-hydroxyphenyl acrylate, 4-hydroxycyclohexyl acrylates, and the methacrylates thereof. Any of the known organic diisocyanates can be used and illustrative thereof one can mention 2,4-(or 2,6-) tolylene diisocyanate, 3-isocyanatomethyl -3,5,5-trimethylcyclohexyl isocyanate, diphenylmethane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dianisidine diisocyanate, xylylene diisocyanates, hexamethylene diisocyanate, dicyclohexyl-4,4'-methane diisocyanate, as well as any of the other known organic isocyanate.
The urea-urethane-polyacrylate oligomers are those compounds obtained by the reaction of a hydroxy substituted organic ester of acrylic acid or methacrylic acid as hereinbefore defined, an organic diisocyanate as hereinbefore defined and a hydroxylamine of the formula:
HOR'NHR
wherein R' is a linear or branched divalent alkylene group of from 1 to 12 carbon atoms, cycloalkylene of 5 to 12 carbon atoms or arylene of 6 to 12 carbon atoms and R is as previously defined.
Illustrative of suitable hydroxylamines one can mention aminoethanol, the aminopropanols, the aminobutanols, the aminohexanols, the aminodecanols, methyl ethanolamine, the aminocyclohexanols, aminobenzyl alcohol, or any other amino alcohol.
In producing the urea-urethane-polyacrylate oligomers the amount of each reactant used is selected so that the theoretical number of equivalents of isocyanato groups charged to the reaction mixture is from about 80 percent to about 105 percent of the sum total of the number of equivalents of hydrogen atoms reacted therewith that are present in the hydroxyl and amino groups in the hydroxylamine and in the hydroxy substituted ester of acrylic acid or methacrylic acid. Preferably the number of equivalents of isocyanato groups is from 95 to 100 percent thereof. When the polyisocyanate contains more than two isocyanato groups and is a tri-or tetra-or higher isocyanate then one can produce a crosslinked product. The preferred compositions are those which are produced with the diisocyanates since they are less viscous. In practice an excess of the hydroxyhydrocarbyl acrylate or hydroxy substituted acrylic acid ester is preferably used since it can also serve as a solvent medium for the reaction.
Theoretically though applicant does not intend to be bound thereby, the primary reaction product obtained by the reaction of a hydroxyhydrocarbyl acrylate (HAA), a diisocyanate (DI) and a hydroxylamine (HA) can be represented by the general structure
HAA--DI-HA--.sub.n DI-HAA
wherein n is an integer having a value of from 1 to 10, preferably from 1 to 3. Thus, the unit HAA has the structure ##STR5## The unit DI has the structure ##STR6## wherein X is a residue of the isocyanate compound and the unit HA represents the structure ##STR7## when a triisocyanate or higher functional isocyanate is used the crosslinked structure presents a more complicated formula and those skilled in the art are well able to write these out. The molecular weight of the product can be controlled by controlling the ratio of hydroxyhydrocarbyl acrylate to hydroxylamine charged to the reaction mixture. The greater the amount thereof the lower the molecular weight since the hydroxyhydrocarbyl acrylate acts as a chain terminator for the reaction.
The reaction can be carried out in the presence of a solvent to facilitate stirring and as solvent one can use any conventional solvent or an intermediate which is desirably present in the subsequently formulated coating or ink but which does not interfere with the reaction at the present time. The reaction is carried out at a temperature of from about 10° to 75° C., preferably from 20° to 50° C. The time required will vary depending upon the specific reactants employed, the temperature, the size of the batch and other variables. Those skilled in the art are fully familiar with the effects of these variables and will know when to stop the reaction.
Normally a catalyst is present for the urethane reaction for the production of the urea-urethane polyacrylate oligomers at the conventional concentration known to those skilled in the art. The catalysts and the concentrations to be used are known to vary depending upon the particular amine or tin catalyst employed.
These catalysts are so well known that they should not require more than a brief mention. They include triethylene diamine, morpholine, N-ethyl-morpholine, piperazine, triethanolamine, triethylamine, N,N,N',N'-tetramethylbutane-1,3-diamine, dibutyltin dilaurate, stannous octoate, stannous laurate, dioctyltin diacetate, lead octoate, stannous oleate, stannous tallate, dibutyltin oxide, etc.
The polyfunctional acrylate-urethane is present in the coating or ink compositions at a concentration of from about 20 to 99 weight percent, preferably from about 30 to 60 weight percent. Illustrative thereof are the reaction products of (a) equimolar amounts of 2-hydroxyethyl acrylate (HEA), trimethyl-hexamethylene diisocyanate and 2-hydroxypropyl acrylate (HPA); (b) equimolar amounts of HEA, isophorone diisocyanate (IPDI) and HPA; (c) one mole of the polycaprolactone diol obtained by the reaction of epsilon-caprolactone with diethylene glycol having an average molecular weight of about 500, two moles of IPDI and two moles of HEA; (d) one mole of the same polycaprolactone diol, two moles of an 80/20 mixture of 2,4- and 2,6- tolylene diisocyanates, one mole of HEA and one mole of HPA; (e) one mole of the polycaprolactone triol obtained by the reaction of epsilon-caprolactone with glycerol having an average molecular weight of about 540, three moles of IPDI and three moles of HEA; (f) one mole of a polyoxypropylene diol having an average molecular weight of about 300, two moles of IPDI and two moles of HEA; (g) one mole of ethanolamine, two moles of IPDI and 2 moles of HEA.
The coating or ink composition can also contain from 0 to 50 weight percent, preferably from 10 to 30 weight percent of at least one polyfunctional acrylate crosslinker. These polyfunctional acrylate crosslinkers are any of the di-, tri-, or tetra-acrylate esters of acrylic acid or methacrylic acid with the di-, tri-, or tetra-alcohols. They are well known compounds and include for example, neopentyl glycol diacrylate, the diacrylate of 2,2-dimethyl-3-hydroxypropyl 2, 2-dimethyl-3-hydroxy propionate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, trimethylol propane triacrylate, or the methacrylates thereof.
The preferred polyfunctional acrylate crosslinkers are neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate and pentarethritol tri-/tetra-acrylate.
The carbamoyl-free monofunctional acrylate can be present at a concentration of from about 0 to 30 weight percent of the coating or ink composition, preferably from 5 to 20 weight percent. These monofunctional acrylates are any of the esters of acrylic acid or methacrylic acid and they are well known to those skilled in the art. Illustrative thereof one can mention methyl acrylate, the propyl acrylates, the butyl acrylates, the hexylacrylates, 2-ethylhexyl acrylate, decyl acrylate, cyclohexyl acrylates, phenyl acrylate, benzyl acrylate, tolyl acrylate, as well as those hydroxyl substituted esters of acrylic or methacrylic acid hereinbefore set forth, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, phenoxyethyl acrylate, glycidyl acrylate, or any other known monoacrylate, as well as the methacrylate derivatives of any of the enumerated compounds.
The coating or ink compositions can additionally contain any of the conventional stabilizers, flow control agents, slip-aids, fillers, pigments, or other additives known to those skilled in the art to be useful in coating and ink formulations. In addition, one can also include a small amount of conventional solvent if this is desired. However, such addition would detract to some extent in that it presents an air pollution problem if it is a volatile solvent. In those instances in which the coating or ink is to be cured by light radiation means, the composition can contain from 0.1 to 20 weight percent of a photoinitiator or photosensitizer. Any of the known photoinitiators or photosensitizers can be used and as examples thereof, one can mention benzophenone, diethoxyacetophenone, the ethyl and butyl benzoin ethers, mixtures of benzophenone with amines such as methyl diethanolamine, or any other known photoinitiator.
Where the coating or ink composition is to be cured by thermal or electron methods, the presence of a free radical initiator at a concentration of from 0.1 to 5 weight percent is advantageous. Illustrative thereof one can mention benzoyl peroxide, di-t-butyl peroxide, t-butyl hydroperoxide, azo-bis-isobutyronitrile, isopropyl peroxide, or any other free radical initiator.
When cure is by electron beam, the use of an initiator is optional.
The compositions of this invention are produced by mixing the components to be used by conventional mixing or blending procedures. These conditions are well known to those skilled in the art and require no elaboration herein since there is nothing critical in the mixing procedure employed.
In a typical embodiment (a) 30 parts of 2(N-methyl-carbamoyl) ethyl acrylate, (b) 35 parts of the oligomer obtained by the reaction of 540 parts of the polycaprolactone triol obtained by the reaction of epsilon-caprolactone with glycerol having an average molecular weight of about 540 with 348 parts of tolylene diisocyanate and 232 parts of 2-hydroxyethyl acrylate, (c) 20 parts of neopentyl glycol diiacrylate and (d) 15 parts of 2-ethylhexyl acrylate and 2 parts of n-butyl ether of benzoin as photoinitiator are mixed at ambient temperature until uniform. This composition when coated on a metal or wood substrate cures to a hard uniform film upon exposure to ultraviolet light radiation under a nitrogen atmosphere.
The following examples further serve to illustrate the invention; parts are by weight unless otherwise indicated.
EXAMPLE 1
There were charged to a flask 222 grams of isophorone diisocyanate, 167 grams of 2(N-methylcarbamoyl)ethyl acrylate as solvent (MCEA) and 0.5 gram of dibutyltin dilaurate. This was heated to 50° C. Then 30.5 grams of 2-aminoethanol was added over a period of 17 minutes in a dropwise manner while controlling the temperature at about 50° C. The reaction was stirred an additional 2.75 hours at 50° C. until the exothermic reaction appeared to have terminated. Over an 80 minutes period 135 grams of 2-hydroxyethyl acrylate was added while maintaining a temperature of about 50° C. The mixture was then stirred for an additional 1.25 hours at 50° C. and permitted to cool to room temperature. The product was a 70 percent solution of the acrylate-terminated urea-urethane oligomer in the solvent.
A radiation curable composition was produced by mixing 11.43 parts of the above oligomer solution, 3.77 parts of 2(N-methylcarbamoyl) ethyl acrylate, 4.8 parts of neopentyl glycol diacrylate and 0.4 part of a mixture of the n- and iso- butyl ethers of benzoin as photoinitiator. This composition had a Gardner-Holdt viscosity of U. A thin film was coated on to Bonderite No. 37 steel and cured by exposure to the continuum light radiation from an 18 kilowatt argon swirl-flow plasma arc for 0.6 second. The cured film was about one mil thick; it had a Sward Hardness of 56, acetone resistance more than 300 seconds and a Taber Wear factor of 2.8 using CS-17 wheels and one kilogram weights for 200 cycles with the wear results reported in milligrams of weight loss per 100 cycles. Impact resistance and adhesion values were low. Similar results were obtained when irradiated for 0.15 second.
EXAMPLE 2
A radiation curable composition was produced using 14.29 parts of the oligomer solution of Example 1, 1.71 parts of 2(N-methylcarbamoyl) ethyl acrylate, 4.0 parts of neopentyl glycol diacrylate and 0.4 part of the same photoinitiator. The coating composition had a Gardner-Holdt viscosity of Z1. The coating cured as in Example 1 had a Sward Hardness of 50, acetone resistance more than 300 seconds and a Taber Wear factor of 2.3. Similar results are obtained when irradiated for 0.15 second.
EXAMPLE 3
Following the procedure similar to that of Example 1, a mixture of 900 grams of trimethylhexamethylene diisocyanate, 668 grams of 2(N-methylcarbamoyl) ethyl acrylate as solvent and 2 grams of dibutyl tin dilaurate was initially reacted with 122 grams of 2-aminoethanol and then with 540 grams of 2-hydroxyethyl acrylate over a period of about 6.5 hours, and then allowed to cool. The product was a 70 percent solution of the acrylate-terminated urea-urethane oligomer in the solvent.
A radiation curable composition was produced by mixing 45.7 parts of the above oligomer solution, 16.3 parts of 2(N-methylcarbamoyl) ethyl acrylate, 25 parts of neopentyl glycol diacrylate, 7 parts isodecyl acrylate, 6 parts of 2-hydroxyethyl acrylate, 7 parts of silica flatting agent and 2 parts of a mixture of the n- and iso- butyl ethers of benzoin as photoinitiator. This composition had a Gardner-Holdt viscosity of C. The composition was applied to a vinyl asbestos tile heated to 82° C. and then cured as described in Example 1. The cured coating was about 3 mils thick; it had a Sward Hardness of 20, a 60° Gardner Gloss of 63, a Taber Wear factor of 18.3 milligrams loss per 500 cycles and a 100 percent crosshatch adhesion value.
EXAMPLE 4
A radiation curable composition was produced using 55.7 parts of the oligomer solution of Example 3, 13.3 parts of 2(N-methylcarbamoyl) ethyl acrylate, 25 parts of neopentyl glycol diacrylate, 6 parts of 2-hydroxyethyl acrylate, 7 parts of the silica flatting agent and 2 parts of the photoinitiator. The composition had a Gardner-Holdt viscosity of I. The coating cured as in Example 3 had a Sward Hardness of 16, a 60° Gardner Gloss of 58, a Taber Wear factor of 18.5 mgm/500 cycles and a 90 percent crosshatch adhesion value.
EXAMPLE 5
A series of curable compositions was produced containing the following parts by weight:
______________________________________ A BOligomer of Ex. 3 18.29 18.29MCEA 6.51 0.51Neopentyl glycol diacrylate 10.00 10.00Isodecyl acrylate 2.80 2.802-Hydroxyethyl acrylate 2.40 8.40Silica filler 2.80 2.80Photoinitiator of Ex. 3 0.80 0.80Gardner-Holdt viscosity D A-B______________________________________
The compositions were coated on to vinyl asbestos tile at room temperature and cured by exposure in air to U V irradiation from six 2.2 kilowatt medium pressure mercury lamps for about one second followed by exposure under nitrogen to irradiation of 2,537 Angstroms from low pressure mercury lamps for about one second. The dry, cured films were about 3 mils thick and had the following properties:
______________________________________ A BSward Hardness 16 1260° Gardner Gloss 64 52Taber Wear, 100 cycles 7.6 8.1______________________________________
EXAMPLE 6
This series shows the viscosity reducing effect of 2(N-methylcarbamoyl) ethyl acrylate in a coating composition when it is used to replace a portion of the oligomer. Surprisingly, the physical properties were not unduly affected and, in fact, impact properties were greatly improved.
A polycaprolactone-polyurethane-polyacrylate oligomer was prepared by reacting 5,450 parts of polycaprolactone triol having an average molecular weight of about 540 that was produced by the reaction of epsiloncaprolactone with glycerol, 5,225 parts of an 80/20 mixture of 2,4- and 2,6- tolylene diisocyanate and 7,030 parts of 2-hydroxyethyl acrylate in the presence of a catalyst. Initially 2,088 parts of the 2-hydroxyethyl acrylate was reacted with the tolylene diisocyanate; this was followed by the addition of the polycaprolactone triol and then by the addition of 1,392 parts of the 2-hydroxyethyl acrylate. After 4 hours at about 30° C. the remaining 3,550 parts of 2-hydroxyethyl acrylate was added. The product was an 80 percent solution of the oligomer in 2-hydroxyethyl acrylate.
A series of curable compositions was produced containing the following parts by weight:
______________________________________ A B C DOligomer of Ex. 6 40 30 20 20Neopentyl glycol diacrylate 25 25 15 33.42-Hydroxyethyl acrylate 15 15 15 20.02-Ethylhexyl acrylate 20 20 20 26.6MCEA -- 10 20 --Gardner-Holdt viscosity G-H -- A2 A3Photoinitiator of Ex. 3 2 2 2 2______________________________________
The compositions were coated on Bonderite No. 37 steel panels and cured by the procedure described in Example 1 under a nitrogen atmosphere using an exposure time of about 1.7 to 1.9 seconds. The films had the following properties:
______________________________________ A B C DSward Hardness 20 24 10 24Taber Wear, 100 cycles 1.8 1.8 2.9 7.1Reverse Impact, in-lb 15 110 120 --Stain Resistance Exc Exc Exc Good______________________________________
The results show that replacement of the urethane oligomer by MCEA in compositions B and C lowered the viscosity as compared to control composition A. At the same time, however, the impact properties of compositions B and C of this invention improved vastly and there was no loss of abrasion resistance properties. Control composition D, which closely resembles composition C but which does not contain any MCEA had much poorer abrasion resistance.
EXAMPLE 7
An oligomer was prepared by charging 450 parts of trimethylhexamethylene triisocyanate, 530 parts of 2(N-methylcarbamoyl) ethyl acrylate as solvent and 0.89 part of dibutyl tin dilaurate to a reactor and heating to about 50° C. Then, over a 30 minutes period the following reactants were added in the sequence stated; 270 parts of the polycaprolactone triol used in Example 6, 118 parts 2-hydroxyethyl acrylate, 270 parts of the polycaprolactone triol described in Example 6 and 130 parts of 2-hydroxyethyl acrylate. Thereafter the reaction was stirred at 50° to 55° C. for 4.5 hours and let stand to cool. The product was a 70 weight percent solution of the oligomer in the solvent.
The above oligomer solution was further diluted in one series of compositions with additional quantities of 2(N-methylcarbamoyl) ethyl acrylate (Series I). In a second series the same original oligomer solution was diluted with a 50/50 weight mixture of 2-hydroxyethyl acrylate and 2-ethylhexyl acrylate (Series II). The purpose was to compare hardness and abrasion resistance of coating compositions diluted with 2(N-methylcarbamoyl) ethyl acrylate to coating compositions diluted with the other acrylates. It was also found that a comparison made on equal coating viscosity rather than on weight percent acrylate dilution, films produced using 2(N-methylcarbamoyl) ethyl acrylate as the diluent possessed better hardness and abrasion resistance properties. The coatings were applied to Bonderite No. 37 steel panels and cured by the procedure described in Example 6 using a 1.2 seconds radiation exposure period. The coatings contained 2 weight percent of the initiator described in Example 3.
______________________________________Series I% MCEA added toOligomer solution 0 10 20 30 40 50Pencil Hardness F F F F F FTaber Wear, 100 cycles 1.3 2.1 2.4 2.7 3.3 3.7______________________________________
______________________________________Series II% HEA/2-EHA addedto Oligomer solution 0 10 20 30 40 50Pencil Hardness F F B 2B 6B 6BTaber Wear, 100 cycles 1.5 2.9 25.7 47 60 72______________________________________
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Compositions based on 2(N-alkylcarbamoyl) alkyl acrylate have been prepared which are useful as coatings and inks.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to the small holes located at the end of an object, and more specifically, needle-holes.
[0002] Threading a needle has always been a difficult task. Thread is flimsy, so a person has a hard time trying to place that thread through the small needle hole. There are no current products that ease the process of threading a needle. This is mainly because a person practiced in dealing with needles can thread one quickly, and easily.
[0003] Threading a needle can be frustrating and difficult to one not used to threading needles. Therefore, it is desirable to have a needle that is very easy to thread, cheap, and easy to manufacture.
SUMMARY OF THE INVENTION
[0004] The primary objective of this invention is, therefore, to make the threading of a needle easier and faster. The other objective would be to allow a wider range of people to use needles. This includes young children, seniors, or anybody else that did not previously have the control needed to thread a needle. The design of the needle must also be simple, cheap, and easy to produce because a consumer would not be interested in buying an expensive needle, even if it is easy to thread.
[0005] While the novel features of the invention are set forth with particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed descriptions taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 shows a prior art needle in its entirety
[0007] [0007]FIG. 2 illustrates an enlarged view of one possible design for the new needle hole
[0008] [0008]FIG. 3 illustrates another example of needle hole design.
[0009] [0009]FIG. 4 illustrates another example of needle hole design, using a movable part.
[0010] [0010]FIG. 5 illustrates a needle hole where the thread is inserted at the head.
[0011] [0011]FIG. 6 illustrates a needle with a large opening at the side, similar in design to that of a hook.
[0012] [0012]FIG. 7 illustrates a prior art spool, at one angle.
[0013] [0013]FIG. 8 illustrates a prior art spool, from another angle.
[0014] [0014]FIG. 9 illustrates a spool that will keep the thread taut.
[0015] [0015]FIG. 10 illustrates a spool that will keep the thread taut and slanted at an angle.
DETAILED DESCRIPTION OF THE INVENTION
[0016] [0016]FIG. 1 shows a prior art needle. The dotted lines enclose an enlarged view of the needle hole ( 101 ). The needle hole is where the thread is strung through. Since the hole is like a slit in the needle, it can be hard to insert the thread through the little hole. The hole is completely enclosed.
[0017] [0017]FIG. 2 illustrates a needle that has been changed in the area around the needle hole ( 201 ). This modified needle hole is exactly the same as a conventional one, except there is a thin cut ( 203 ) at the side of the needle hole. This allows the user to easily slide the thread in through the thin cut, instead of pushing the thread through the hole. The thin cut is angled so that it is hard for the thread, once inserted, to slide out the needle hole. This is because when a needle is used, the thread is pulled toward the head ( 202 ) of the needle. Since the thin cut is at the other end of the needle hole, and because the thin cut is angled the opposite direction that the thread is moving, it will not be likely for the thread to slide back out the needle hole.
[0018] [0018]FIG. 3 illustrates another needle hole. The design is very similar to that of the needle hole in FIG. 2. The only difference is how the thin cut is angled. This v-cut ( 301 ) is shaped like the letter v. It juts in diagonally one way, and then it juts diagonally the opposite way. Therefore, once the thread has been inserted the correct way, it will be very unlikely that the thread will slide back out the needle hole. This is because the thread must change direction exactly when it is at the vertex ( 303 ) of the v-cut. As stated before, the thread is being pulled toward the head, so it is already unlikely for the thread to slide back into the v-cut. For the thread to change direction in the middle of the v-cut is highly unlikely. Therefore, using the v-cut, a simple, effective method is being used to keep the thread in, while at the same time, making it easy to thread the needle.
[0019] [0019]FIG. 4 illustrates another design for a new needle hole. This design uses a moving part. The is a diagonal cut ( 401 ) made in the needle. This diagonal cut is just thinner than the thickness of thread, to prevent the thread from being inserted there. There is another section of the needle where a whole triangular section in cut out. This is the triangle cut ( 403 ). The triangle cut is made so that a the base of the triangle opens up into the needle hole. This will allow the section of needle between the diagonal cut, and the triangle cut, to move inwards. However, the triangle cut does not cut the needle into parts. The needle is still intact as a thin part of the needle connects the flexible region ( 402 ) to the region to the right of the triangle cut. The flexible region is made of a durable, yet flexible material like copper. This makes it so the flexible region can move inwards, allowing a person to place the thread inside the needle hole. However, the diagonal cut is placed so that the shaded region can only move inwards just enough to let the thread through. This is so that once the thread is inserted; the shaded region can easily be bent back into place as it has not been bent too far out of place.
[0020] [0020]FIG. 5 illustrates another unique design for the needle. What used to be the head of the needle, is now a slanted opening ( 501 ). The slanted opening slants inward to allow a person is easily slide the thread into the needle hole. The slanted opening is also just wide enough to allow the thread to go on through. This is one reason why the thread will stay in the needle hole. There is also a nook ( 503 ) that the thread will be pushed into once in the needle hole. This nook can hold the thread because the thread is wider than the nook. Therefore, if forced into the nook, the thread will stay there and not move towards the tip of the needle, thus making it almost impossible for the thread to escape out of the needle hole.
[0021] [0021]FIG. 6 illustrates another version of the design seen in FIGS. 2 and 3. Instead of a cut, this design uses a wide opening ( 601 ) so that it is very easy to slide the thread in. The wide opening is about two-thirds the size of the needle hole. This is so that a person will have a very easy time inserting the thread in the right place. Once the thread is inside the wide opening, it must pass through the narrow opening ( 603 ). The narrow opening is just wide enough to let the thread through. A little force will be required to push the thread through. The narrow opening must be this narrow to ensure that the thread cannot unintentionally escape the needle hole. Again, there is a nook ( 503 ) that catches the thread and prevents it from moving around.
[0022] [0022]FIG. 7 illustrates a prior art spool. Spools are the devices used to carry thread.
[0023] [0023]FIG. 8 illustrates a spool from another angle.
[0024] [0024]FIG. 9 illustrates a spool with two small slits ( 901 ) on opposite ends of the spool. This allows the thread ( 903 ) to be tightly strung across the spool. This keeps the thread taut, which is ideal for the threading of the new modified needle holes. This way, the thread is kept taut and it will not move from its current position, as it is being kept in place by the two slits. This allows a person to easily place the thread into the correct position inside the needle hole. Whereas two hands would normally be required to keep the thread taut, and to control it at the same time, now, only one hand would be required to hold the spool, while the other can control the needle. This makes the modified needles more practical as the threading of the needles can be easily done with two hands. One hand controls the thread so the other hand only needs to hook the thread into place.
[0025] [0025]FIG. 10 illustrates an alternate method of keeping the thread taut on the spool. This involves a beam ( 1001 ) to be placed reaching from one end of the spool to the other. On the beam is a small slit ( 1003 ) that the thread can be inserted into. This slit will hold the thread ( 903 ) tightly, resulting in a taut section of thread being stretched from the beam to the main body of the spool. This produces the desired effect, allowing the thread of the modified needle to be quick and easy.
[0026] While specific embodiments of the invention have been illustrated and described herein, it is realized that other modifications and changes will occur to those skilled in the art. For example, there will be a wide variety of methods to improve on the modified needle hole. In our examples, the thread is inserted through cuts in the side. It is also possible to use different methods to hold the thread. It should be understood that the above particular examples are for demonstration only and are not intended as limitation on the present invention. It is therefore to be understood that the appended claims are intended to cover all modifications and changes as fall within the true spirit and scope of the invention.
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The present invention was invented in order to ease the process of threading a needle. It also gives people, who do not have the coordination to thread a needle, the ability to sew and knit. The present invention allows a wider range of people to use needles, and improves the ease of which sewing is done. The design is simple and easy to produce keeping the needles price at a low amount.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention relates to a method for monitoring the functional capability of a tank venting system that traps fuel fumes and leads to an internal combustion engine for a motor vehicle, on the basis of a negative pressure generated in the tank venting system, including a container adsorbing fuel fumes and communicating with a fuel tank through a venting line and with an intake tube of the engine through a regeneration line; an aeration line communicating with the atmosphere and being closable by a shutoff valve for monitoring the tank venting system; a pressure sensor detecting the system pressure of the tank venting system; a tank venting valve being disposed in the regeneration line, being opened to supply the fuel fumes stored in the container and building up a negative pressure in the tank venting system; wherein the tank venting system is classified as currently nonfunctional if the pressure gradient upon buildup of the negative pressure (negative pressure buildup testing) is below a threshold or the pressure gradient upon letup of the negative pressure (negative pressure letup testing) is above a further threshold; and additionally operating variables of the vehicle including of the engine and the tank venting system are monitored, and the method is discontinued if predetermined operating variable values at which a reliable statement about the functional capability is possible, are not attained.
One such monitoring method and an apparatus therefor are known from German Published, Non-Prosecuted Application DE 41 32 055 A1, corresponding to U.S. Pat. No. 5,398,661.
That disclosure describes a tank venting system which has a tank with a tank pressure sensor, an adsorption filter which communicates with the tank through a tank connection line, and an aeration line closable by a shutoff valve, and a tank venting valve that communicates with the adsorption filter through a valve line. A tank venting system which is constructed in that way is checked for functional capability by the following method:
--monitoring of vehicle operating variables, including the engine and the tank venting system, and discontinuation of the test if predetermined operating variables at which a reliable statement on the functional capability is possible, are not attained;
--closure of the shutoff valve;
--opening of the tank venting valve;
--measurement of the negative pressure building up in the tank;
--monitoring of vehicle operating variables that first become measurable during the test procedure, including the engine and the tank venting system, and discontinuation of the negative pressure buildup test if the operating variables indicate that the measured tank pressure values do not allow a reliable statement to be made about the functional capability of the system;
--finding the system to be currently nonfunctional, and termination of the method, if the negative pressure buildup gradient is below a threshold;
--closing the tank venting valve;
--measuring the negative pressure letting up in the tank;
--monitoring vehicle operating variables that are first measurable during the test procedure, including the motor and the tank venting system, and discontinuation of the negative pressure letup testing if the operating variables indicate that the measured tank pressure values do not allow a reliable statement about the functional capability of the system;
--finding the system to be currently nonfunctional, if the negative pressure letup gradient is above a threshold, and otherwise finding the system to be currently functional; and
--opening the shutoff valve and terminating the method.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method for monitoring the functional capability of a tank venting system for a motor vehicle, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods of this general type, which further improves previously known and proposed methods and which in particular refines criteria for discontinuation, in which the method is discontinued if an unequivocal statement cannot be made about the functionality of the tank venting system.
The method is also intended to be able to detect very small leaks in the tank venting system on the order of magnitude of 1 mm.
With the foregoing and other objects in view there is provided, in accordance with the invention, in a method for monitoring functional capability of a tank venting system trapping fuel fumes and leading to an internal combustion engine for a motor vehicle, on the basis of a negative pressure generated in the tank venting system, including a fuel tank, a container adsorbing fuel fumes, a venting line through which the container communicates with the fuel tank, an intake tube of the engine, and a regeneration line through which the container communicates with the intake tube; an aeration line communicating with the atmosphere, and a shutoff valve for closing the aeration line to monitor the tank venting system; a pressure sensor detecting a system pressure of the tank venting system; and a tank venting valve being disposed in the regeneration line, being opened for supplying fuel fumes stored in the container and for building up a negative pressure in the tank venting system; the method which comprises classifying the tank venting system as currently nonfunctional if a pressure gradient upon buildup of the negative pressure is below a threshold or a pressure gradient upon letup of the negative pressure is above a further threshold; monitoring operating variables of the vehicle including the engine and the tank venting system, and discontinuing the method if predetermined operating variable values at which a reliable statement about the functional capability is possible, are not attained; and monitoring the dynamic behavior of the pressure course in the tank venting system during the entire performance of the method; by detecting chronologically successive pressure values; forming a mean value of two of the pressure values; and discontinuing the method if an amount of a difference between the mean value and a current pressure value is outside a predetermined dynamic range.
In accordance with another mode of the invention, there is provided a method which comprises defining different dynamic ranges for testing the pressure buildup and testing the pressure letup.
In accordance with a further mode of the invention, there is provided a method which comprises defining the dynamic range to be small in the pressure letup testing, as compared with the dynamic range for the pressure buildup testing.
In accordance with an added mode of the invention, there is provided a method which comprises ascertaining a proportion of volatile fuel in the container as the operating variable; opening the tank venting valve and the shutoff valve for a time being dependent on the ascertained degree of loading of the container in order to carry out a scavenging operation on the container; detecting values occurring for minimal and maximal pressure in the tank venting system, after the end of the scavenging operation, during a predetermined period of time; and discontinuing the method if a difference between the values is below a limit value.
In accordance with an additional mode of the invention, there is provided a method which comprises closing the tank venting valve and the shutoff valve; detecting a starting pressure and detecting a final pressure after a predeterminable period of time has elapsed; forming a difference between the two values and comparing the difference with a first threshold value; discontinuing the method due to excessive outgassing of fuel if the difference is above the first threshold value; and otherwise utilizing the value as a correction factor for evaluating the pressure in the negative pressure letup testing.
In accordance with yet another mode of the invention, there is provided a method which comprises whenever the difference is below the first threshold value: comparing the difference with a limit value; discontinuing the method and recognizing an incompletely closed tank venting valve if the difference is below the limit value; and otherwise utilizing the final pressure as a starting value for the negative pressure buildup testing.
In accordance with yet a further mode of the invention, there is provided a method which comprises opening the tank venting valve in increments, to generate the negative pressure in the tank venting system, with the shutoff valve closed.
In accordance with yet an added mode of the invention, there is provided a method which comprises opening the tank venting valve through a ramp function of a predeterminable pitch.
In accordance with yet an additional mode of the invention, there is provided a method which comprises opening the tank venting valve for a predeterminable period of time; checking as to whether within the predeterminable period of time the pressure in the tank venting system beginning at the starting value has reached a diagnostic negative pressure value, and if that condition is met without a violation of a lambda controller threshold of a lambda controller of the engine having occurred during the predeterminable period of time; suddenly closing the tank venting valve; and detecting and utilizing the instantaneous pressure value as the starting value for the negative pressure letup testing.
In accordance with again another mode of the invention, there is provided a method which comprises closing the tank venting valve in increments if the lambda controller threshold is violated, to prevent a sudden leaning down of the mixture supplied to the engine; and discontinuing the method.
In accordance with again a further mode of the invention, there is provided a method which comprises, whenever within the predeterminable period of time the diagnostic negative pressure has not been attained, nor has any violation of the lambda controller threshold of the lambda controller taken place: detecting the pressure in the tank venting system after the predeterminable period of time elapses; then checking if the pressure beginning at the starting pressure has dropped by a minimum value being decisive for the extent of leakage in the tank venting system; drawing a conclusion as to a middle-sized leak in the tank venting system if the pressure has dropped by the minimum value; and otherwise drawing a conclusion that there is a very large leak, a tank venting valve is sticking in the closed state, an activated charcoal filter container shutoff valve is sticking in the open state, or a gas cap is missing, and entering the type of ascertained error in an error memory of an electronic control unit for the engine.
In accordance with again an added mode of the invention, there is provided a method which comprises detecting the pressure in the tank venting system and storing the pressure in the tank venting system in memory as a final pressure of the negative pressure letup testing, with the tank venting valve closed, beginning at the starting value for the negative pressure letup testing, after a time period has elapsed; forming a difference between the final pressure and the starting pressure; weighting the difference with a correction factor, for taking slight outgassing of fuel into account in the evaluation of the functional capability of the tank venting system; comparing the corrected difference with a threshold value; classifying the tank venting system as currently functional if the threshold value is not attained; and otherwise drawing a conclusion that there is a very small leak in the tank venting system.
In accordance with a concomitant mode of the invention, there is provided a method which comprises informing a driver of the vehicle at least one of acoustically and visually of at least one of an ascertained error and a type of error.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for monitoring the functional capability of a tank venting system for a motor vehicle, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and block circuit diagram of an internal combustion engine with a tank venting system and an electronic control unit for monitoring the functional capability of the tank venting system;
FIG. 2 is a flowchart showing one complete method cycle for monitoring the functional capability of the tank venting system;
FIG. 3 is a more-detailed flowchart for FIG. 2, pertaining to a test for hydrocarbon outgassing;
FIG. 4 is a more-detailed flowchart for FIG. 2, pertaining to a generation of negative pressure and testing of a negative pressure buildup;
FIG. 5 is a more-detailed flowchart for FIG. 2, pertaining to a testing (diagnosis) of negative pressure letup; and
FIG. 6 is a diagram showing a course over time of pressure in the tank venting system during selected method steps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen a simplified illustration of a tank venting system for a motor vehicle, that has a fuel tank 10 with a fill neck, which is not identified by a reference numeral but can be hermetically sealed with a gas cap 11. Branching off from the fill neck in the vicinity of a filling opening thereof is a vent line 12 for use when the tank is being filled. The vent line 12 opens out into the fuel tank 10 again at a point located farther away from the filling neck. Fuel fumes, i.e. vapor that develops in the process of filling the tank 10, can flow back again upward in this venting line 12 for use while the tank is filling, so that the fuel tank can be completely filled with fuel.
This line 12 also communicates with a first terminal of a differential pressure sensor 13, while a second terminal of the sensor 13 communicates with the atmosphere. However, in the case of the method for monitoring the functional capability of the tank venting system according to the invention, it is not important for the differential pressure sensor 13 to be placed at the location shown in FIG. 1. On the contrary, the sensor 13 may be disposed at any arbitrary point within the tank venting system.
The fuel tank 10 communicates through a vent line 14 with an activated charcoal filter container 15, in which hydrocarbon vapors outgassing from the fuel tank 10 are adsorbed. An equalization container 16 with an integrated tank protection valve assembly 17 is provided in the vent line 14, between the activated charcoal filter container 15 and the fuel tank 10. On one hand this assures that liquid fuel cannot directly reach the activated charcoal filter container 15, for instance if the fuel tank 10 is completely filled or if the vehicle comes to rest on its roof (rolls over) due to an accident. On the other hand, it assures that the complete tank venting system is protected from the occurrence of an excessively pronounced negative pressure or overpressure of malfunctioning components of the tank venting system, both during a scavenging operation and during the monitoring process.
A regeneration line 18 extends from the activated charcoal filter container 15 and opens downstream of a throttle valve 19 disposed in an intake conduit 20 of an internal combustion engine 21. A flow control valve 22, which is referred to below as a tank venting valve (TVV), is disposed in the regeneration line 18. An aeration line 23 is provided at the bottom of the activated charcoal filter container 15. The aeration line 23 communicates with the ambient air and can be shut off through the use of an electromagnetic activated charcoal filter shutoff valve (ASV), which is referred to below as a shutoff valve 24 for short.
A three-way catalyst 26 and an oxygen sensor in the form of a lambda sensor 27 disposed upstream of the catalyst 26, are provided in an exhaust conduit 25 of the engine 21. The sensor 27 outputs a signal UL to an electronic control unit 28 of the engine 21, in accordance with the proportion of oxygen in the exhaust gas. Other control parameters which are needed for operating the engine, such as the rpm N, the coolant temperature TCW, and the aspirated air mass AM are detected by suitable sensors and are also delivered to the control unit 28.
These parameters are then further processed, in such a way that the load state of the engine 21, among other factors, is determined, and if needed scavenging of the activated charcoal filter container 15 or a monitoring routine for the tank venting system can be initiated.
One such monitoring routine will be described below in broad steps, referring to the flowchart of FIG. 2. In the case of individual method steps S2.4 to S2.6, a description will follow below with reference to FIGS. 3-6.
The monitoring routine is enabled only if certain enable conditions are met. To that end, in a first step S2.0 a check is performed as to whether or not the engine is in the idling mode and the vehicle speed is equal to zero. Since speeds of v=0 can be detected only at relatively major effort and expense, vehicle speeds which while greater than 0 are still below a certain limit value (for instance 1.8 km/h) are used as the signal for v=0 and are therefore not a guarantee that the vehicle is at an absolute standstill. Moreover, the engine must have reached a minimum temperature, which is ascertained by comparing the currently measured coolant temperature with a predetermined limit value.
Monitoring of the tank venting system is carried out through the use of a negative test pressure, which is generated by opening the tank venting valve 22 in the engine idling state. The fuel tank 10 is evacuated through the activated charcoal filter container 15, with the aid of the relatively pronounced negative pressure in the intake tube during engine idling. If the activated charcoal filter container is saturated, it is possible for a rich mixture to be sent into the intake tube through the then-opened tank venting valve 22. The lambda integrator of the lambda control device is tuned very slowly in engine idling and cannot detect a sudden hydrocarbon production resulting from the rich mixture until relatively late, so that the danger exists that the engine will die. In order to avoid this, the degree of saturation of the activated charcoal ascertained during normal tank venting function, or in other words during the scavenging mode of the activated charcoal filter container, is taken into account.
If the enable conditions of step S2.0 are met, then through a mark A, a step S2.1 is reached, in which a load degree of the activated charcoal filter container 15, that is often referred to as the degree of saturation, is determined. Depending on the ascertained load degree, at partial load of the engine, variously long scavenging times of the activated charcoal filter container are initiated, before the monitoring of the tank venting system for tightness can be carried out. The scavenging time is longer if the loading degree is high than if the loading degree is low. This avoids a situation in which the activated charcoal has an overly high loading degree before monitoring begins, which would falsify the outcome of the monitoring.
In order to ascertain the loading degree of the activated charcoal filter container, the lambda regulating position is detected with the tank venting valve entirely or at least partially closed. Ascertainment of this load is most accurate if the tank venting valve was fully closed at the onset of this ascertainment. However, for reasons of the necessary activated charcoal filter container scavenging rate, it is appropriate in some cases to close the tank venting valve only to the extent of a limit duty cycle. If the tank venting valve is not yet closed, or if this limit duty cycle is not attained, then the duty cycle DC of the trigger signal for the tank venting valve is decreased through a ramp function until such time as the requisite outset position is present.
The duty cycle DC of the trigger signal for adjusting the tank venting valve is formed during normal operation, that is during the tank venting function, from a pilot control value KF -- DC and a correction value 0≧FAK -- TE≧1, which are linked multiplicatively. The loading state of the activated charcoal filter container can be determined through purposeful variation of this correction value. For a certain length of time corresponding to a certain number of P jumps of the lambda controller, the tank venting valve remains closed, or as noted above remains minimally opened, and the lambda regulating position is detected. Since the lambda control constantly attempts to adjust the fuel-air mixture to the stoichiometric ratio (λ=1), and the equilibrium of this ratio is impeded by the opened tank venting valve as a function of the degree of loading of the activated charcoal filter container, the difference between the lambda control positions (which are also called lambda controller mean values) LAMMV -- DIFF -- TE before and after triggering of the tank venting valve is a measure of the loading of the activated charcoal filter container.
Depending on the value of this difference LAMMV -- DIFF -- TE, variously long scavenging times are initiated.
If the requisite scavenging time has elapsed, then through a mark C a step S2.3 is attained, in which an examination is performed as to whether or not pressure fluctuations in the fuel circulation and in particular in the fuel tank might falsify the monitoring of the tank venting system. Since splashing of the fuel in the tank can deleteriously effect the pressure measurements, a study is made as to whether or not within a certain period of time pressure fluctuations occur, and whether or not they are possibly within an allowable tolerance limit. To that end, during an adaptable time period with the aid of the differential pressure sensor 13, the pressure in the tank venting system is measured continuously, and the maximum and minimum pressures that occur are ascertained. If the difference between these two values is within a fixed measurement window, then a correct starting pressure for subsequent measurements can be obtained, and in a step S2.4 a test for hydrocarbon outgassing follows.
However, if the pressure fluctuations in the step S2.3 are too great, one test condition has not been met, and a new ascertainment of the pressure fluctuations is carried out. This is repeated until such time as the pressure difference is within the allowable measurement window.
Prior to the actual negative pressure testing, it is ascertained in the step S2.4 whether or not a negative pressure can be allowed to be produced in the fuel tank. Since fuel fumes, for example resulting from the effects of heat in the tank venting system, can represent a further source of problems in evaluating the functional capability of the system, the monitoring routine is terminated if outgassing is too severe, and a new ascertainment of the degree of loading with an ensuing scavenging process in accordance with steps S2.1 and S2.2 awaited. In the step S2.4, it is also learned from pressure measurements whether or not the tank venting valve 22 is sticking in the open or partly open state, and if so the diagnosis is discontinued and the method is restarted at the step S2.1.
If no fuel outgassing is occurring in the step S2.4, or if the quantity of outgassing fuel is below a predetermined limit value, then in a step S2.5 a negative pressure is generated in the tank venting system by opening the tank venting valve. If the pressure in the system then fails to drop by a certain value within a predetermined time, the monitoring is discontinued, and the method for this cycle is ended (at a mark G). The tank venting function is thereupon enabled (at a step S2.7). However, if the thresholds of the lambda integrator of the lambda controller fail to be observed within this period, then the method is recontinued at the step S2.1.
If not, through a mark F, a step S2.6 is reached in which a check is made as to whether or not the negative pressure built up in the tank venting system is letting up (negative pressure letup testing) in a predetermined way.
Depending on the outcome of this testing, the conclusion is drawn either that there is a leak in the tank venting system or that the system is intact.
In both cases, in the next step S2.7 the tank venting function is enabled and the monitoring method is ended.
In order to select out pressure values that could cause misdetections in the event of an erratic pressure course in the fuel tank, caused by slamming of a vehicle door or hard braking of a slowly rolling vehicle, the dynamic performance of the pressure course is monitored over the entire method cycle. The term "limited dynamics, pressure course" is introduced for that purpose. First, the mean value P -- MV i of the current pressure value P i is formed with the most recent pressure value P i-1 : ##EQU1##
The limited dynamics are satisfied if the amount of the difference between the mean value P -- MV i and the current pressure value P i is below a predetermined value, which is referred to below as the dynamic window value P -- DYW:
|P.sub.-- MV.sub.i -P.sub.i |<P.sub.-- DYW.
In the case of the steps S2.4, S2.5 and S2.6 shown in FIG. 2, different dynamic window values can be defined. During the negative pressure letup testing (step S2.6) and the testing for hydrocarbon (HC) outgassing (step S2.4), the dynamic window value P -- DYW is chosen to be low in proportion to the dynamic window values in testing of the negative pressure buildup (step S2.5). As a result, the accuracy of monitoring in the various method steps can be adjusted, and misdetections can be avoided in a purposeful way.
Moreover, it is also possible to define the dynamic window values as a function of the fill level of the fuel in the tank.
If the limited dynamics are violated while running through the various steps, then the monitoring is discontinued, and before a new monitoring is started, one must wait until the pressure conditions in the tank have stabilized. An applicable time (waiting time T -- WAIT) is thus waited out in a step S2.8, and then in a step S2.9 the tank venting function is enabled, and the method is continued at a mark C.
However, the statement "test conditions not met" in steps S2.3-S2.6 in FIG. 2 does not mean only the discontinuation criterion "limited dynamics, pressure course", but also other discontinuation criteria. If during monitoring of the tank venting system, diagnostic errors in ascertaining the rpm or coolant temperature occur or if malfunctions of the components, that is the tank venting valve, the lambda controller, the throttle valve, the tank pressure sensor or the shutoff valve occur, then once again as in the case of the discontinuation, a transition to the waiting time state (step S2.9) is made through the limited dynamics. This happens if during an ongoing monitoring routine the engine leaves the idling state, or the speed of the vehicle exceeds a threshold value.
If the monitoring of the tank venting system is discontinued because the pressure rise in the test of fuel outgasses (step S2.4) is greater than a limit value, or if the lambda controller value changes by more than a predetermined value during the production of the negative pressure (negative pressure buildup testing, step S2.5), then before the next monitoring is carried out, a new load ascertainment (step S2.1) is awaited.
The Step S2.4 includes substeps S3.1-S3.8 shown in FIG. 3. First, the shutoff valve 24 (ASV) and the tank venting system 22 (TVV) are simultaneously closed (step S3.1), and a starting pressure P -- A is ascertained (step S3.2). After an adaptable time T -- 1 elapses, a pressure measurement is again carried out, and the outcome of this measurement is stored as a final pressure P -- B in a working memory of the electronic control unit 28 (step S3.3). Next, in the step S3.4, a difference P -- CORR between the final pressure P -- B and the starting pressure P -- A is ascertained:
P.sub.-- CORR=P.sub.-- B-P.sub.-- A.
If the value P -- CORR is above a fixed threshold value P -- THR 1 (interrogation in step S3.5), then the monitoring is discontinued, because excessive outgassing of the fuel is present, which represents a possible source of trouble in evaluating the outcomes of monitoring.
However, if the interrogation in the step S3.5 has a negative outcome, that is if the value P -- CORR is below the threshold value P -- THR 1, a checked is performed in a step S3.6 as to whether or not it is also below a further limit value P -- TVV. If the pressure in the tank venting system during a time T -- 1 drops below the value P -- TVV, then it can be concluded from this that the tank venting valve 22 cannot be completely closed but instead must be sticking in the open state or at least the partly open state, even though in the step S3.1, by triggering the tank venting valve 22 in the "closing" direction, the tank venting system should have been tightly sealed. The monitoring is discontinued analogously to when there is a positive response to the interrogation in the step 3.5, and a new load ascertainment is carried out in the step S2.1.
If the value for the pressure P -- CORR is above the value P -- TVV, which represents a tank venting valve that is sticking while open, then in steps S3.7 and S3.8 both the value P -- CORR and the value for the final pressure P -- B are stored in memory. The latter then serves in the ensuing negative pressure buildup testing (FIG. 4) as a starting value for the pressure measurements still to be carried out.
Instead of using individual values for the starting pressure P -- A and the final pressure P -- B, mean values from a certain number of pressure values (for instance four of them) for P -- A, P -- B may also be used.
In the diagram of FIG. 6, a solid line qualitatively indicates a course of pressure over time in the tank venting system during the steps S2.4-S2.6, and the pressure values P -- A through P -- B that occur at the beginning and the end of these steps are also shown. The times during which the tank venting valve and the shutoff valves are open and closed are also shown.
If in the step S2.4 neither excessive outgassing of the fuel nor a tank venting valve sticking open were found, and moreover if all of the test conditions are met, then through a mark E a step S4.1 (FIG. 4) is reached. While the shutoff valve 24 remains closed, the tank venting valve 22 is triggered with the aid of the electronic control unit 28 in such a way that the flow cross section of the regeneration line 18 is increased continuously up to a predeterminable diagnostic value. The incremental enlargement of the flow cross section is accomplished, for instance, by triggering the tank venting valve 22 through the use of a ramp function. This prevents a possible hydrocarbon surge from the activated charcoal filter container from being delivered too suddenly, through the open tank venting valve 22, to the combustion process of the engine, which could cause the engine to die or briefly worsen engine emissions.
The negative pressure prevailing in the intake tube is propagated through the open tank venting valve within the entire tank venting system up to the fuel tank. If the pressure beginning at the starting pressure P -- B drops far enough, within an opening time T -- 2 of the tank venting valve, that a predetermined diagnostic negative pressure value P -- DIAG is reached, then in a step S4.3 the tank venting valve 22 is closed abruptly, and an instantaneous pressure value P -- C then prevailing is stored in memory (step S4.4) as a starting value for a subsequent diagnosis (FIG. 5). The method is then continued through the mark F with the step S2.6 (FIG. 2).
If the interrogations in the steps S4.2 and S4.5 find that the predetermined diagnostic pressure P -- DIAG was not attained even though the time T -- 2 has already elapsed, then evidently it is not possible for negative pressure adequate for monitoring to be built up in the tank venting system. In order to enable at least roughly estimating the cause of this, a checked is performed in a step S4.6 as to whether or not the pressure drop attained is greater than or less than a minimum pressure value. The minimum pressure value is chosen in such a way that when this value is reached, in a step S4.7, a conclusion is drawn as to a medium-sized leak (for instance>2 mm), and otherwise in a step S4.8 that there is a large leak, a missing gas cap on the fuel tank, or a tank venting valve that is sticking in the closed state. In both cases, an entry is made in an error memory of the electronic control unit (step S4.9). In addition, the outcome can be reported acoustically and/or visually to the driver of the vehicle. Next, in a step S4.10, the shutoff valve 24 is opened again and the tank venting function is enabled. Since it was not possible to generate a negative pressure necessary for monitoring the tank venting system, the routine is thus ended.
If the thresholds of the lambda integrator of the lambda controller are violated during the opening duration T -- 2 of the tank venting valve (step S4.11), or in other words if the lambda controller value varies during the negative pressure buildup testing (extraction by suction) by more than a predetermined value since the beginning of the extraction by suction, then the monitoring is discontinued, and the tank venting valve is slowly reclosed in increments (step S4.12).
If the tank venting valve were to be closed without any limitation on the variation of the various values, for instance abruptly, then there would be the danger that the fuel-air mixture would suddenly lean down and the engine would die.
Next, the shutoff valve is opened and the tank venting function is enabled (step S4.13). Through the mark A, the step S2.1 is again reached, and there is a wait for a new ascertainment of the degree of loading. Once the pressure has been ascertained (value P -- C in step S4.4), a transition is made to the negative pressure letup testing state (diagnosis in FIG. 5). In this state, there is a wait until a predeterminable time (diagnosis time), such as T -- 1 has elapsed, and then a resultant final pressure P -- D is measured (step S5.1) and stored in memory. Then in a step S5.2, the pressure difference P -- D-P -- C between the diagnostic starting pressure and the diagnostic final pressure is formed. This difference is also corrected with the pressure value P -- CORR from the step S3.4 (FIG. 3), by subtracting that value from the difference P -- D-P -- C. Thus the pressure rise caused by weak outgassing of fuel is taken into account in the evaluation of the functional capability of the tank venting system.
With the aid of this value for the corrected pressure difference, the decision is then made as to whether there is a relatively small leak in the tank venting system, or not. If this value is below a predetermined threshold value P -- THR 2, then the tank venting system is considered to be functioning properly. Otherwise a leak larger than 1 mm is found, and the outcome is entered in the error memory. Regardless of whether or not an error has occurred, through the mark G a step S5.7 is reached, in which the shutoff valve is opened, the monitoring for this engine operation is shut off, and the tank venting function is enabled.
In the purely qualitative representation of the pressure ratios during the various monitoring steps in FIG. 6, a simplification has been made that after the closure of the tank venting valve in the step S4.3, no trailing of the pressure takes place, or in other words no further drop in the pressure. A slight trailing of the pressure of this kind is determined by the storage capability of the lines, or in other words essentially by the geometry of the components of the tank venting system, and can be taken into account or in other words compensated for by inserting a dead time. After closure of the tank venting valve, there is a wait for this dead time before the diagnostic starting value P -- C is ascertained and the diagnosis time T -- 1 is started.
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A method for monitoring functional capability of a tank venting system for a motor vehicle, includes evacuation of the tank venting system through the use of negative pressure or vacuum prevailing in the suction tube of an internal combustion engine and assessing the system based on negative pressure buildup and negative pressure letup gradients. Additionally, besides other abnormal termination criteria, the dynamics of pressure changes are also monitored and the method is immediately discontinued, if pressure fluctuations are ascertained which exceed a predetermined measure.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation under 35 U.S.C. §120 of U.S. Utility application Ser. No. 10/413,994, filed Apr. 16, 2003, entitled SYSTEM AND METHOD FOR MANAGING INFORMATION RETRIEVALS FOR INTEGRATED DIGITAL AND ANALOG ARCHIVES ON A GLOBAL BASIS, which was based on and asserted priority under 35 U.S.C. §§119 and 120 to U.S. Provisional Patent Application No. 60/108,245, filed Nov. 13, 1998, and U.S. Utility application Ser. No. 09/439,909, filed Nov. 12, 1999, the latter two applications both being entitled SYSTEM FOR MANAGING INFORMATION RETRIEVALS FROM DISTRIBUTED DOCUMENT ARCHIVES ON A GLOBAL BASIS, and the entire disclosures of the aforementioned three applications being hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention generally relates to systems and methods for electronic information retrieval and more particularly to systems and methods for retrieving information from logically and geographically distributed and incompatible storage devices containing both digital and analog content.
BACKGROUND OF THE INVENTION
Historically, corporations have used paper, microfilm and microfiche media for the long term storage of information important to the corporation. Each of these types storage media can take massive amount of physical storage space, and require considerable effort when the retrieval of stored information is necessary. Such media are still widely in use, both for historical and current archiving of information. Electronic storage archives have been developed that enable large electronic repositories that facilitate relatively easy retrieval of electronic files. Typically, these electronic storage archives allow the long term archival of document bitmap images, computer generated reports, office documents (e.g., word processing documents and spreadsheets), audio and video files, etc.
The hardware typically incorporated in an electronic archive is comprised of a general purpose computer and storage devices (such as magnetic disks, optical disks and magnetic tape subsystems). The hardware is typically operated and accessed by software comprising an operating system, database management systems, hierarchical storage management software (HSM) and archive management software. There are at least four significant limitations associated with current long term archival systems. First, larger corporations will invariably require several geographically diverse heterogenous archival systems in order to support the various operations of the corporation throughout the country and the world. For example, The corporation's research and development facility in London England has a separate archival system from the archival system for one of the corporation's manufacturing sites in Dallas Tex. Even if each of the archive facilities has a heterogeneous archival (e.g., a database manager) the hardware and the software comprising the archival at the two sites is invariably provided by two different vendors whose proprietary product are not interoperable (i.e., the software at the London site cannot be used to access the information stored at the Dallas site).
A related second problem is that even if the hardware and the software at the London and Dallas are from the same vendor, the corporation will typically not have any mechanism for managing information accesses at the enterprise level, treating all of the corporation's archives as single resource regardless of the location.
A third significant problem is that an electronic document stored in one format can only be used by the specific retrieval applications that support that document storage format. Frequently, retrieval applications have very different formatting requirements, thus creating further compatibility problems. For example, a check image contained in the archive facility of a bank is typically in TIFF-JPEG or TIFF-G4 format while the image of a bank statement is typically in IBM AFP, Xerox Metacode or Adobe PDF format. The retrieval application (e.g., Netscape or Microsoft browser) or device (Palm PC, smartphone) frequently cannot display images in the format in which the images are stored. Although both electronic files are images, they cannot be retrieved by the same retrieval application. This compatibility problem severely limits the range of retrieval solutions and frequently increases the cost and time in building custom file conversion functions.
Analog archives, in particular microfilm and microfiche media, is fairly well entrenched in some corporations and government agencies. The rate of migration to digital repositories in these organizations has been slower than expected.
One reason for hesitation in abandoning analog archives are technology obsolescence issues dealing with digital storage media and digital file formats over the very long term future. For example, some corporations archived data on eight inch or five and one quarter inch floppy disks. Finding the disk drives to even accept these disks, let alone the operating systems to read them is a daunting task. It has been challenging to prove that digital objects can be preserved and viewable beyond 50 years. Analog media (paper, microfilm, microfiche, and ion beam etching) can last hundreds of years and can be read with ubiquitous optical systems that are easily available or even replicable. Digital media (tapes, diskettes, optical storage (e.g., Compact Disks)) also degrade over time (e.g., 15-25 years) and must be re-recorded to preserve the information encoded thereon.
One further reason that some businesses have been slow to embrace digital archiving is that digitizing analog media can be very expensive. Many customers leave historical analog media ‘as is’ while using digital repositories on ‘day forward’ documents.
A final significant limitation with current archive systems is that these systems impose great challenges in applying enterprise level management and control processes including consolidated usage tracking and billing information; performance measurement and management; uniform access and retrieval application and security and a uniform look and feel for document displays.
Accordingly, it is an object of the present invention to allow users to have a unified information retrieval front-end and user experience across all digital as well as analog information repositories. It is a further object to facilitate a gradual migration path for users from analog to digital repositories.
SUMMARY OF THE INVENTION
In light of the above problems associated with the traditional archive retrieval systems, the present invention manages information retrievals from all of an enterprises' archives across all operating locations. All of the electronic archives as well as analog archives, regardless of the location, configuration or vendor makeup are linked to provide a single global framework for managing archive access. It thus provides system developers with a single “virtual archive” for accessing all of the enterprises' stored data, without the need to have location dependent programming code.
A first aspect of the present invention is the user interface. The goal achieved by the present invention with respect to the interface is to provide a single, consistent and user friendly interface. This is accomplished through the use of an intranet access portal. This single entry point for users is preferably enabled using a browser which provides access for the user to several retrieval application. By the use of a single entry point, users are able to access multiple applications through a single sign-on and password.
A second significant aspect of the present invention is the use of logical tables (“meta-descriptors”) that are used to direct information retrieval requests to the physical electronic archives. By the use of these tables, no change what-so-ever (hardware or software) is required to the archives. The tables provide a high degree of location independence to information retrieval applications by creating a “virtual archive.” This concept of a “virtual archive” provides for rapid application development and deployment, resulting in lower development and maintenance costs. The virtual archive furthermore allows for data aggregation (regardless of location) so the a user can have data from multiple physical locations on a single screen in a single view.
A third aspect of the present invention is the functionality of reformatting and repackaging the retrieved information. This is required because of the above described incompatibility between the format of the stored information and the distribution media. A final function performed by the present invention is automatic disaster recovery.
A further significant aspect of the present invention is the use of statistical analysis techniques in providing the requester with predicted response time based on historical performance of request queues. Depending on the requested object type, storage media of the requested object, overall archive workload factors and equipment (e.g., number and availability of tape drives), etc., the response time may be sub-second or several minutes. Using empirical performance statistics, multiple performance profile models (PPM's) are developed. Each retrieval request is classified with a matching PPM, and a delay factor (in seconds or minutes) is sent to the requesting application or user whenever response delays are expected.
In one embodiment of the invention, users of the digital repositories of the present invention are provided with the capability to also have a duplicated copy on analog media. The digital document is typically used for regular operation purpose while the analog copy is typically intended only for very long term document preservation.
The present invention provides significant advantages to a corporation over the existing archive systems. Document archives can be consolidated at strategic locations globally. Each location archive can serve the archival needs for all product and service lines of the corporation and provide generic storage capability covering a broad range of objects including office documents, document images, computer print reports, etc. Each business division of the corporation can leverage and share document management products developed by other divisions at much reduced costs and lead-time. The present invention allows many business divisions to have presence at multiple global geographical locations. A document archival infrastructure that could be leveraged on a global basis facilitates a global service reach objective. Many new information retrieval products (e.g. customer Internet retrievals) can be provided though a single customer access point regardless of physical storage locations. This level of transparency in customer accesses to consolidated global information can be critical to a corporation's competitiveness in the new information age. Furthermore, since the present invention allows to user to access both digital and analog media using the same integrated front end, the invention facilitates a gradual migration path for users from analog to digital repositories.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purposes of illustrating the present invention, there is shown in the drawings a form which is presently preferred, it being understood however, that the invention is not limited to the precise form shown by the drawing in which:
FIG. 1 depicts a high level diagram illustrating the components of the archive manager of the present invention;
FIG. 2 illustrates the main component parts of the archive access manager of the present invention;
FIG. 3 depicts an overview of the processing and flow of information through archive access system;
FIG. 4 illustrates the processing that occurs in the Input Processing section of the Business Application Interface Manager;
FIG. 5 depicts the process followed by the Retrieval Fulfillment module;
FIG. 6 shows the processes flow performed by the Archive Interface Manager;
FIGS. 7 and 8 illustrate the processes of the Output Control Section of the Core Processing Block; and
FIG. 9 depicts the process followed by the Output Processing module of the Business Application Interface Manager.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates, at a high level, the system of the present invention and its relationship with respect to the electronic archives 100 - 106 of an enterprise and with respect to users 150 , 160 of those archives. Illustrated in FIG. 1 are four different archives. Archives 100 and 102 represent domestically located archives while archive 104 is located in Europe. Element 106 represents an analog archive facility containing analog archives 111 . Although only four archives 100 - 106 are depicted in this Figure, the present invention is scalable such that the access to any number of electronic archives can be managed by the present invention. The archives 100 - 106 are heterogeneous in configuration meaning that they are constructed of diverse constituent elements (e.g., hardware and software) and store a wide diversity of types of information.
Schematically included in each of the archives 100 - 104 are the physical storage devices 110 , the software 112 for accessing the physical devices 110 , the site specific software 114 for controlling access to archived information, and site specific messaging system 116 for communication with a site. Typical storage devices 102 include Direct Access Storage Devices (DASD), optical storage devices and magnetic tape devices. These storage devices are typically configured in a hierarchical manner such that information that is more recent or that is more often accessed is stored on devices with the quickest access time, for example DASD. Using conventional archiving techniques, as electronic information “ages”, it is migrated for archival purposes from DASD to devices with a slower access time such as optical disks or magnetic tape. Optical disks and tape provide a cost effective means for the storage of large quantities of electronic information. Tapes are typically stored and accessed through tape silos while a large quantity of optical disks are stored and accessed from one or more jukeboxes. Some specific examples of storage devices 110 include IBM and EMC magnetic disks, STK magnetic tape silos, Boxhill RAID magnetic disks, and Hewlett Packard magneto-optical jukeboxes.
Element 106 represents an analog archive facility that contains at least one analog storage device 111 . Such a device includes microfilm, microfiche and ion beam etched devices. For the purposes of information retrieval with respect to the present invention, these devices 111 broadly fall into two types of categories, those with a digital index and those without.
In the process of creating an analog document (e.g., using a KODAK Digital Writer device to create microfilm), a digital index is preferably created. This digital index is used for future data retrievals from the analog archive 111 (e.g., film roll number, film starting frame position, number of frames). The index information is stored in a digital archive. At retrieval time, the retrieval system 130 (discussed in further detail below) first consults the digital index on the digital archive, then uses the index information to request the stored information (e.g., a document) from the analog archive 106 facility.
The analog archive facility 106 acts on the request, manually locates the analog document, digitizes the document (e.g., using a microfilm scanner) into a standard digital file (e.g. TIFF file) then returns the digital document to system 130 (discussed in further detail below).
It is possible that future new technology will allow analog archives to be managed by automated library technology, similar to automated magnetic tape silos, e.g. robotic arms to pick the requested microfilm cartridge, spool and advance microfilm to the requested starting frame, scan/digitize the number of microfilm frames into a digital file.
Many analog archives 111 do not have a digital index associated therewith. Traditional microfilm archives typically rely on paper or microfiche reports as index information. There is accordingly no digital index to assist the user or the retrieval personnel in the retrieval process.
Under the present invention, system 130 permits the user to send a free format text message to the analog archive area 106 . The request describes the information being requested (e.g., a document) for example by the date or date range of the document. The personnel manning the analog archive area 106 acts on the request, manually locates the analog document(s), digitize the document (microfilm scanner) into a standard digital file (e.g. TIFF file) then return the digital document to the Archive Access Manager.
In a preferred embodiment of the present invention, the corporation is a financial institution (e.g., a bank) and the electronic information that is stored in storage devices 110 is generated an relied upon during the normal course of business for the institution. The banking industry furthermore has special regulations as to the storage and retention of certain type of documents such as checks. The following are some examples of the type of information stored in devices 110 by a bank and some of the different types of format in which the same data can be stored. Check images and document images can be stored in the following formats: TIFF/JPEG Multi-page; TIFF/G4 Multi-page; Federal Reserve bank Common Output Format (COF); TIFF/ABIC (gray scale or binary); IOCA/ABIC (gray scale or binary); MOD:CA/G4; JPEG; GIF; Encrypted binary files; and BLOB (binary large object). Computer reports and statements can be stored as: IBM AFP; Xerox Metacode; Adobe PostScript; HP PCL; Adobe PDF; ASCII text; and EBCDII text. Office documents can be stored for example as Microsoft Word document, Excel or PowerPoint files or as HTML files. Other Objects which are stored in archive storage devices 110 include XML documents, Audio files (WAV, MP3, etc), Video files (MPEG2, MPEG3, AVI, etc).
Each digital archival site 100 - 104 has its own specific set of media control application software 112 that is used to access the electronic information stored on the physical devices 110 located at the site. The type of media control software 112 will depend on the types and number of devices located at the site. Furthermore, even if two sites 100 - 104 have the same types of hardware devices 110 , the media control software 112 employed at a particular site is very likely provided by a particular vendor and therefore be incompatible with the media control software 112 at a different site which has been provided by a different vendor. The same is true of the archival control software 114 . This software is the application or suite of applications which provides the user interface for accessing all of the stored electronic information stores in the archives at a site 100 - 104 . The archival control software 114 interfaces with the media control software 112 and is therefore site specific. The media control software 112 and archival control software 114 are typically hosted on hardware such as IBM RS6000 SP computers or Sun Microsystems servers and includes such software as IBM AIX or SUN Solaris operating systems, IBM DB2 DBMS, IBM OnDemand archive manager, IBM ADSM media manager, and SYBASE System 11 DBMS AMASS storage manager. The present invention maintains a profile of each of the archives through the use of tables. A preferred format of the archive application profile table is illustrated in Table 1.
As seen in FIG. 1 , the archival control software 114 also interfaces with the software component of the messaging system 116 employed at each site. The messaging system 116 will also vary from site to site, typically being provided by different vendors such as the MQSeries from the IBM corporation.
The electronic messaging system 116 is also used to deliver a user request to the Analog Archive service location 106 . Preferably, the messaging system 116 delivers a work ticket that is printed with the request details (archive, e.g., customer ID, Request ID, Request date/time, film roll number, film starting frame position, number of frames for indexed). Using such a work ticket, the operator at the analog archive 106 is able to locate the analog document. If the analog archive 111 in facility 106 is a microfilm archive 111 , the operator scans the microfilm using a microfilm scanner and creates a digital file. If archive 111 is a paper archive, the operator scans the paper document using an optical scanner to create a digital file. Similar scanning devices exist for other types of analog archives 111 (e.g., microfiche and ion beam etching) that allow the operator to create a digital copy of the requested analog document.
Element 130 represents major components of the archive access system of the present invention, the system 130 contains two archive access managers 140 A and 140 B. In accordance with conventional disaster recovery techniques, one of the access managers 140 A is located at physical site A and the second access manager 140 B is located at a physical site B. The operations between these sites A and B are mirrored thereby providing quick recovery should one or the other of the sites experience an outage. Either of the sites 140 A or 140 B is capable of handling the complete load of the system 130 . Each of the access managers 140 A and 140 B communicates with the geographically distributed archives 100 - 106 though messaging systems 135 and a cross connect matrix 120 . The cross connect matrix allows both of the sites 140 A and 140 B to communicate with any of the messaging systems 116 at the various sites 100 - 106 . In one embodiment of the present invention the cross connect matrix 120 consists of the public Internet.
Three different user interfaces are depicted in relation to the archive system 130 . The first is for employees of the corporation 150 denoted as internal users. This interface can be enabled through the Internet using common browser technology, through a client/server configuration or through a customer Application Program Interface (API) specially developed for access to the archive management system 130 . The other two classes of interfaces are similar, but are used by external users, typically customers of the corporation. In one embodiment, an external user 165 uses an Internet browser application to connect to the system 130 through a customer gateway 145 . The gateway 145 comprises the proper security mechanisms, for example a firewall, to ensure that only authorized users are allowed to connect to the system 130 and eventually the archives 100 - 106 . The last user interface shown in FIG. 1 is by an eternal user 167 through a custom API developed especially for access to the system 130 . This type of interface would be used by a customer with special needs such as requiring special access or the transference of large amount of data on a regular basis. As with the gateways 145 , access to system 130 through the custom APIs is controlled using proper and conventional security mechanisms. The details of each of the requesting applications employed by the various users 150 , 160 of the system are kept in tables. Table 2 illustrates a preferred format of the requesting application tables. These tables allow system 140 to quickly identify the requesting application and all of the parameters associated with the application.
FIG. 2 illustrates the main component parts of the archive access manager 140 of the present invention. The archive access manager 140 discussed with respect to this Figure is the configuration of both of the archive access managers 140 A and 140 B discussed with respect to FIG. 1 . The four main components are a Business Application Interface Manager (BAIM) 200 , a Core Processing Module (CPM) 215 , an Archive interface manager (AIM) 235 , and an Administrative manager 240 . In overview, the BAIM 200 provides the user interface for receiving requests for archived data from customers 150 , 160 and for transmitting the requested data back to the customer 150 , 160 once the archived data has been retrieved. The CPM 215 is responsible for the management of file retrievals and reformatting of data. The AIM 235 performs the actual retrievals of electronic information from the various archives 100 - 106 . The Administrative Manager 240 performs various administrative functions with respect the operation of the archive access system 140 .
FIG. 3 depicts an overview of the processing and flow of information through archive access system 140 . In step 300 the BAIM Input Processing section 205 (see FIG. 2 ) receives and processes information requests from users. It is determined in step 310 what type of information is being requested. If the information is data which can be located using database indexes, the request is forwarded to the AIM module 235 in step 320 which retrieves the data from the archives 100 - 106 . Upon retrieval of the data, it is processed in step 330 for presentation to the user by the Output Processing module 210 of the BAIM 200 . In a preferred embodiment, this retrieval occurs in two steps. First, the relevant index is retrieved and presented to the user (e.g., the user requests to see checks for the month of August from a particular account). When the user selects particular data items to view from the retrieved index, the system 140 retrieves the actual data for presentation to the user. Since indexed data is typically stored on DASD (quick retrieval time) the more complex retrieval process (e.g., prioritization) employed for the retrieval of documents described below is not required but could be used.
If the requested information is a document or a file, the request is queued in step 340 by the Queue Management section 220 of the CPB 220 . The streamlined process described above with respect to data retrievals is less effective for documents or other files (e.g., images) since these types of electronic information are more likely archived in longer term storage such as tape or optical disks. Requests are processed off the queue (or queues) in step 350 by the Retrieval Fulfillment module 225 which passes the request to AIM module 235 for retrieval of the document or file in step 360 . After the document or file has been retrieved from the archives 100 - 106 , it is first processed by the Output Control section 230 of the CPB 215 in step 370 and then passed onto the Output Processing section 210 of the BAIM 200 for final preparation for presentation to the user in step 380 .
As described above, the BAIM module 200 receives requests for archived information from customers 150 , 160 and transmits the retrieved information back to the customer 150 , 160 . BAIM 200 accomplished these functions by its Input 205 and Output 210 processing components. As described above with respect to FIG. 1 , there are generally three types of business applications employed by users 150 , 160 in communicating with the archive access manager 140 of the present invention: Internet/Intranet applications; Client-Server applications; and Messaging based applications. In a preferred embodiment, the present invention supports the following interface protocols: IP/HTTP, CORBA and IBM MQ Series, although the present invention can be modified to support virtually any interface protocol. XML data structures can be used within all interface messages.
Internet/Intranet applications use the IP/HTTP protocol and Internet Browsers (such as Netscape Navigator or Microsoft Internet Explorer). Intranet applications can be built with JAVA, C++, Javascript, Vbscripts, or other such languages. Client/Server applications require a communications network and a server for communicating with the archive access manager 140 from a user work-stations and can be built with programming tools such as Visual Basic, Visual C++, Visual FoxPro, PowerBuilder or JAVA.
Messaging systems such as IBM MQ Series or Microsoft MSMQ can also be used to communicate between a user applications and archive access manager 140 . Such systems pass information from system to system using discrete messages. Messaging application systems may operate in asynchronous mode or real-time synchronous mode (e.g., via Tuxedo/M3, RPC calls, especially suited for overseas communications). Using messaging is a preferred method of communication with archive access manager 140 since messaging allows diverse platforms to communicate cost-effectively.
Both Input Processing 205 and Output Processing 210 sections of the BAIM 200 are queue driven. As a user logs onto system 140 , the user is identified by its requestor application ID and assigned a request queue. The Input 205 and Output 210 Processing sections share the same queue in accordance with the requestor application ID. The queue structure allows for accurate tracking and auditing of the status of a request from a user. As requests come in from users, the Input Processing section 205 places the request on the queue assigned to the user and as the requested data comes back from the archives 100 - 106 , the Output Processing section 210 marries up the retrieved information with the request.
FIG. 4 illustrates the processing that occurs in the Input Processing section 205 of the BAIM 200 . One of the first functions of the Input Processing section 205 is to validate (steps 400 - 405 ) the format and contents of the request from a user. The request is determined to be invalid, the request is rejected and in step 410 an error message is generated from return to the user. The error message will inform the as to the reason(s) why the request was rejected. In step 415 the audit log for the system is updated with the fact that the request was rejected. The audit log is file which is updated for any significant event which occurs with respect to a request (e.g., the request was passed onto the next processing section). In validating the request, the Input Processing section 205 checks both the format and the content of the request.
In a preferred embodiment for requests for digital information, each request assembled and transmitted by the user's application 150 , 160 contains the following fields: a request source area ID, the requestor application ID described above; an archive application ID; a request Date/Time; a request sequence number; a request type (Data or document/file); an Interface method; a service class; a delivery format; whether and what type of encryption is required; whether and what type of authentication is required; and a request parameter string. A preferred format of the information request entry is depicted in Table 3.
In step 420 depicted in FIG. 4 , the Input Processing section 205 determines the storage location that has archived the data/document/file being requested by the user 150 , 160 . At the startup of system 14 , a storage location table is created in system memory from the meta-descriptor tables. This table enable a high speed look-up of the storage locations of the information requested by the user. Table 4 depicts a preferred format of the archive location table. In the case of requests for analog information that does not have a digital index, the system is able to determine where to send the request from the user's id and the freeform information input by the user (e.g., date or date range for the information.
In step 425 it is determined if the request by the user requires the retrieval of information from multiple sites. This determination is accomplished from the results of the table look-up. If the information is located at only one archival site 100 - 106 , the audit log is update in step 435 and the request is passed on the Core Processing Block 220 for fulfillment (see discussion below with respect to FIG. 7 ). If the request requires information from several sites 100 - 106 , in step 430 the Input Processing section 205 creates the requests for information from the multiple sites 100 - 106 and generates synchronization flags for the coordination of the requests and the retrieval of the information.
As the Core Processing Block 220 receives requests for information retrievals from the BAIM Input Processing section 205 , the requests are queued by the Queue Management module 220 . The service class contained in the request from the user 150 , 160 is used by the Queue Management module 220 to set the priority the request. If the Queue Management module 220 has calculated that there will be a delay with respect to fulfilling the request (with respect to the priority indicated by the user in the assignment of the service class) the Queue Management module 220 sends an advice message to the output queue (see below) for immediate delivery to the requesting application.
The Process Retrieval Fulfillment module 255 is responsible for processing the requests from the queues established by the Queue Management module 220 . The process followed by the Retrieval Fulfillment module 225 is illustrated in FIG. 5 . In step 500 , the Retrieval Fulfillment module 225 retrieves the request with the highest priority from the queue. In step 510 , it is determined whether the requested information has previously been retrieved and is already cached by the system 140 . The caching feature of the present invention is more fully described below with respect to the cache control module 255 (see FIG. 2 ). If the information is not found in the cache, the Retrieval Fulfillment module 225 calls the Archive Interface manager 23 - 5 to perform the actual retrieval function (see FIG. 6 and associated description). If the information has been cached, the Retrieval Fulfillment module 225 retrieves the document or file from the cache in step 530 and returns it with a message to the Output Control 230 of the CPB 215 for eventual transmittal back to the requesting user 150 , 160 as described below. As with any substantive action by system 140 , the audit log is updated in step 540 .
The processes flow performed by the Archive Interface Manager (AIM) 235 is depicted in FIG. 6 . As with the other modules, the AIM 235 is queue driven. There is one retrieval queue for each Archive Application ID. Furthermore, there is one instance of the AIM module 235 for each Archive Application ID. The Archive Application IDs represent a logical storage folder. For example, corporate checks might be associated with a first Archive Application ID and bank DDA statements might be assigned to the second different Archive Application ID. Each archive location typically has one or more physical archives and each of the physical archives typically has many Archive Application IDs. For example if there are two archival locations, each with four Archive Application IDs, there will be eight retrieval queues and eight instances of AIM 235 servicing those queues. The AIM 235 performs two general operations, one for sending request messages and one for retrieving the results of the request. In step 600 , AIM 235 constructs a retrieval message based on a request received from the Retrieval Fulfillment module 225 . In step 610 , the retrieval message is through the messaging system to the archive 100 - 106 that contains the requested data and the audit log is updated in step 620 to reflect the fact that the request message has been sent to the archive 100 - 106 .
In order to look for the responses to the request messages, AIM 235 monitors the communication link each of the archives responses in step 620 . If AIM 235 detects that the communications link is disconnected, it sends message to Administrative Manager 240 (see FIG. 2 ). In step 640 , if the time for the expected response from an archive 100 - 106 has expired, AIM 235 generates an error message in step 650 which is subsequently transmitted back to the user 150 , 160 . AIM 235 maintains a timeout value for each retrieval request and monitors the physical communication link for the messages In step 660 , AIM 235 has successfully received the requested document/file from the archive 100 - 106 and forwards the retrieved document/file to the Output Control module 230 for eventual transmittal back to the user 150 , 160 .
The Output Control section 230 of the CPB 215 (see FIG. 2 ) performs two separate routines. In the first routine illustrated in FIG. 7 , the Output Control Section 230 determines in step 710 whether the document/file received from AIM 235 is part of a multi-site request. If the data is not part of a multi-site request, control is passed to the second routine illustrated in FIG. 8 . If the data is part of a multi-site request, the Output Control Section 230 waits until all of the data has been retrieved and then in step 710 aggregates the results. As illustrated in FIG. 8 , the Output Control Section 230 further performs several formatting functions with respect the retrieved data. In step 800 the actual format of the retrieved object is determined and checked against the requested delivery format required by the user 150 , 160 . If reformatting of the document/file (e.g., image) is required, the appropriate reformatting module is selected in step 810 which reformats the data in step 820 .
In step 830 , the Output Control Section 230 determines if encryption is required with respect to the retrieved data. The user 150 , 160 specifies in the original request whether the data as returned to the user 150 , 160 needs to be encrypted and the type of encryption required. In step 840 the appropriate encryption module is selected which obtain encryption key (located in a user profile and security table (not shown) and encrypts the retrieved document/file as specified by the user 150 , 160 . In step 860 it is determined if the authentication is required. Again, the user 150 , 160 in the original request specifies if authentication is requires. In step 870 , the appropriate authentication module is selected which obtain authentication key or digital certificate and authenticates document/file in step 880 .
Documents/files which have been processed (reformatted, encrypted and or authenticated) by the Output Control Section 230 of the Core Processing Block 215 are placed on an output result queue for transmission back the requesting user 150 , 160 by the Output Processing module 210 of the BAIM 200 . The process followed by the Output Processing module 210 is shown in FIG. 9 . In step 900 , the output message containing the retrieved document/file is formatted in XML or other alternative message format. The XML message is then incorporated in a message formatted in step 910 for the particular communication media employed by the user 150 , 160 (e.g., IP/HTTP, CORBA, MQ Series, etc). The properly formatted message is then delivered in step 920 for delivery to the user 150 , 160 thus completing the request operation. As always, the audit log is updated reporting the successful fulfillment of the retrieval request.
FIG. 2 additionally illustrated the administrative functions employed in the archive access system 140 of the present invention. The Statistical Analysis section 245 of the Administrative manager 240 performs various statistical analysis functions including performance measurement & prediction. This function is primarily accomplished by extracting data from the audit log. Some of the useful statistical information which is generated from the audit log includes the access duration and time for each user, and by application ID; the number of documents accessed for each user, and by application ID; and the response time for each access for each user, and by application ID. Each of these statistics is useful in determining the loads, peak times and responsiveness of the system 140 in order that the system may be adjusted in response to the observed performance.
The Statistical Analysis section 245 maintains a statistical data warehouse. From this data, performance predictive profiles can be created, which, for each application, can calculate the average response time for standard DASD retention period and a tape retention period. Statistical analysis techniques are employed that provide the requester with predicted response time based on historical performance of request queues. Depending on the requested object type, storage media of the requested object, overall archive workload factors and equipment (number of availability of tape drives), etc., the response time may be sub-second or several minutes. Using empirical performance statistics, multiple performance profile models (PPM's) are developed. Each retrieval request is classified with a matching PPM, and a delay factor (in seconds or minutes) is sent to the requesting application or user whenever response delays are expected
The Statistical Analysis section 245 further generates and maintains billing statistics from which it creates billing reports and output files for use by management.
The Priority Administration section 250 allows the manual intervention to change the priority number (01-99) for an individual request or a group of requests. This function allows dynamic priority re-assignment during periods where heavy request volumes are creating request backlogs.
As described above, the system 140 caches the most recently retrieved information in order enhance the performance of the system. Often, repeated requests for the same information are made with the same day, week or month. Caching Control module 255 is responsible for maintaining the cached information. Caching control module 255 actively manages the cache retention schedule in which the duration of the caching of particular information varies by the archive application. Different schedule of retention are determined for different types of information based on the pattern of requests for the information. In addition to caching new documents, the Caching Control module 255 is responsible for cleaning up cached documents whose retention period has expired.
Security Management section 260 is responsible for providing standard security administration services to Intranet applications as well as providing standard user sign-in security and checking the authenticity of the requesting business applications. One of the advantageous features of the present invention is that a user 150 , 160 needs only sign on to system 140 once and the Security Management section 260 is responsible for ensuring that the user 150 , 160 is authorized to retrieve the requested information. The user is not required to go through separate sign-on and password procedures for each of the archive systems 100 - 106 from which information is requested.
TABLE 1
Data Element
Type
Comments
Archive
Alphanumeric
Centrally assigned
Application
to each area
ID
Must match IBM
OnDemand application
ID
Application
Character
Name
Contact
Character
Primary storage
Alphanumeric
TIFF/JPEG, TIFF/G4
objects (up to 10
COF, TIFF/ABIC,
object types)
IOCA/ABIC,
MOD:CA/G4, JPEG,
GIF, BLOB, AFP,
Metacode, PostScript,
PCL, PDF, ASCII,
EBCDII, Word, Excel
PowerPoint, HTML,
XML, WAV, MP3
MPEG2, MPEG3, AVI
Primary Archive
Alphanumeric
Centrally assigned to
ID's (up to 10
each area
archives)
A1-Check archive
Houston
A2-Check Archive-
Somerset
B1-Customer archive-
Houston
B2-Customer Archive-
Wilmington
T1-Lockbox archive-
UK
T2-Lockbox archive
Hong Kong
T3-Disbursement
archive-Syracuse
Backup Archive
Alphanumeric
Centrally assigned to
ID's (up to 10
each area
archives)
A1-Check archive
Houston
A2-Check Archive-
Somerset
B1-Customer archive-
Houston
B2-Customer Archive-
Wilmington
T1-Lockbox archive-
UK
T2-Lockbox archive
Hong Kong
T3-Disbursement
archive-Syracuse
Cache rule-
Numeric
No of days
incoming new
items
Cache rule-
Numeric
No of days
retrieved
items
TABLE 2
Data Element
Type
Comments
Requestor Application ID
Alphanumeric
Centrally assigned to
each area
Application Name
Character
Contact
Alphanumeric
Preferred interface
Alphanumeric
protocol
Application descriptions
Alphanumeric
Storage encryption?
Logical
Yes or No
Delivery encryption
Logical
Yes or No
enabled?
Delivery encryption type
Alphanumeric
allowed*
Delivery encryption key
Alphanumeric
Stored encrypted
Delivery authentication
Logical
Yes or No
enabled?
Delivery authentication
Alphanumeric
type allowed**
Delivery authentication
Alphanumeric
Stored encrypted
encryption key
*Encryption Type
ENCRYPTDES = DES Encryption
ENCRYPTDES3 = Triple DES encryption
**Authentication Type
AUTHRSA = RSA Public key authentication
AUTHX509 = X.509 digital certificate authentication AUTHDESMAC = DES MAC private key authentication
TABLE 3
Data Element
Type
Comments
Request Source Area ID
Alphanumeric
Centrally assigned to each
area
Requestor Application ID
Alphanumeric
Centrally assigned to each
area
Archive Application ID
Alphanumeric
Centrally assigned to each
area
Request Date/time
Numeric
Request sequence
Numeric
Sequence control number,
number
assigned by requesting area.
Incremented by 1 for each
request.
Request type
Alphanumeric
D1=Data record(s) only
F1=Document file
F2=Image File
Interface method
Alphanumeric
HTTP=IP/HTTP protocol
CORBA=CORBA protocol
MQ=MQ Series protocol
Service Class
Alphanumeric
Centrally assigned to each
Requestor area.
1-10 Immediate delivery
11-20 Delayed delivery-
same day
90-99 Overnight Delivery
Delivery Format
Alphanumeric
Blank =Original storage
format (Default)
TIFF01=TIFF/G4 or
TIFF/JPEG
TIFFG4=TIFF/ITU G4 only
JPEG=JPEG only
TIFFJPEG=TIFF/JPEG
PDF = Adobe PDF only
Delivery Encryption
Alphanumeric
Blank = (Default)
ENCRYPTDES=DES
Encryption
ENCRYPTDES3= Triple
DES encryption
Delivery Authentication
Alphanumeric
Blank = (Default)
AUTHRSA= RSA Public
key authentication
AUTHX509= X.509 digital
certificate authentication
AUTHDESMAC=DES
MAC private key
authentication.
Request parameter string
Text string
SQL statement string
TABLE 4
Data Element
Type
Comments
Archive ID
Alphanumeric
Centrally assigned to
each archive
Archive Name
Character
Physical address
Alphanumeric
e.g. IPxxx.xxx.xx.xx
physical address
Interface module name
Alphanumeric
Name of the custom
connector module
Interface method
Alphanumeric
HTTP=IP/HTTP
protocol
CORBA=CORBA
protocol
MQ=MQ Series
protocol
Archive Platform
Alphanumeric
A1= IBM OnDemand
on AIX
A2=IBM OnDemand on
Solaris
B1=Sybase/AMASSS
on Solaris
Archive Status
Character
Active
Inactive
Although the present invention has been described in relation to particular embodiments thereof, many other variations and other uses will be apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the gist and scope of the disclosure.
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A system and method for managing information retrievals from all of an enterprises' archives across all operating locations. The archives include both digital and analog archives. A single “virtual archive” is provided which links all of the archives of the enterprise, regardless of the location or configuration of the archive. The virtual archive allows for data aggregation (regardless of location) so the a user can have data from multiple physical locations on a single screen in a single view. A single, consistent and user friendly interface is provided through which users are able to access multiple applications through a single sign-on and password. Logical tables that are used to direct information retrieval requests to the physical archives. The retrieved information is reformatted and repackaging to resolve any incompatibility between the format of the stored information and the distribution media.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a conversion of and has benefit of priority of the following application, which is co-pending and has at least one same inventor of the present application: U.S. Provisional Patent Application No. 61/336,831, titled “Timing soap dispenser base apparatus”, filed Jan. 27, 2010.
TECHNICAL FIELD
[0002] The present invention is related to hand hygiene and is more particularly related to a soap dispenser base apparatus that helps time hand washing duration and encourages more frequent hand washing.
BACKGROUND
[0003] In a variety of different fields, businesses and residences, there is a great desire that people wash their hands more effectively and more frequently. The US Center for Disease Control has stated that “The most important thing you can do to keep from getting sick is to wash your hands”. And yet, many people, through lack of knowledge, poor habits or simple negligence either do not wash their hands frequently enough or effectively enough.
[0004] One of the keys to effective hand washing is the duration of the time one should wash their hands. For many years, parents have instructed their children to time their hand washing by singing songs that last roughly 20-30 seconds (the desired hand washing period) as they wash their hands. A popular example of an attempt to get a child to time their hand washing is singing the “Happy Birthday Song” twice while washing.
[0005] Others (e.g., U.S. Pat. No. 5,771,925) have attempted to take the guesswork out of timing for 20 seconds by including a timing mechanism as part of the soap dispenser apparatus itself. Also, others have attempted to notify a user of the soap of the desired wash duration by providing soap that changes color after some period of time as the soap is being lathered up (example, Inspector Hector™ soap from ViJon Corporation). Other schemes have supplied a marker on a soap dispenser in a manner that tags a mark on the user's hand which requires 20 seconds or so of lathering to wash off (e.g., SquidSoap™ from SquidSoap LP). The attempts described above to help a user know how long to wash their hands all require that each individual soap dispenser have some type of timing, marking or a soap with color changing capability. This requirement that each and every soap dispenser have special timing capabilities can raise the cost of the soap dispenser.
[0006] To help address the problems, another approach provided a timing mechanism in a base product that allowed multiple different soap dispensers to be used on the same timing base (U.S. Pat. No. 7,315,245 and hereinafter the '245 patent). The '245 patent allows for soap dispensers (i.e. bottles) that do not have timing mechanisms and this allows for less expensive soap dispensers than ones which have timing features included on each bottle. The '245 patent provides significant improvements to encourage hand washing.
[0007] It would be advantageous to further entice use of a soap dispenser for hand washing. Enticing hand washing through use of a soap dispenser (especially for children) is an excellent way to get users to wash more often and to wash more thoroughly and effectively. More frequent washing in conjunction with improved hand washing duration can result in dramatically improved hand washing efficacy. Therefore, it would be a significant improvement to provide a cost effective, multi-use soap dispenser that entices use of the soap dispenser for frequent washing and effective washing duration.
SUMMARY
[0008] An embodiment of the invention is a soap dispenser system including a soap container with a pump dispenser. The system includes a base for attaching and supporting in attachment the soap container and the pump dispenser, in combination, and a circuit of the base capable of outputting a plurality of different audible signals. The soap bottle includes attachment means intended to be detachably attached in use to said base, and when attached to the base, communicates with the base and the base selectively outputs one of the plurality of different audible signals corresponding to the soap bottle.
[0009] Another embodiment of the invention is a soap dispenser system including a base with lights and a soap bottle with attachment means capable of detachably connecting to the base. The lights of the base selectively illuminate only when dispensing force is applied to the soap bottle.
[0010] Yet another embodiment of the invention is a soap dispenser system including a soap dispenser base capable of delivering a plurality of different audible signals, lights communicatively connected to the base, and a soap bottle containing soap, the soap bottle includes attachment means capable of detachably connecting to the base. The soap bottle, when connected to the base, is detected by the base via the attachment means. The base selectively delivers one of the different audible signals corresponding to the soap bottle upon, in use, dispensing soap from the soap bottle.
[0011] Another embodiment of the invention is a soap dispenser system for dispensing soap in response to an action including a soap container having a theme identifier device corresponding to the soap container, a supportive base detachably connected to the soap container, a receiver device connected to the supportive base, for detecting the theme identifier device of the soap container when the soap connector is connected to the base, a storage connected to the receiver device, the storage containing data representing a plurality of different human perceptible media, at least one of the plurality corresponds to the theme identifier device of the soap container, an output device for delivering the plurality of different human perceptible media, and a processor connected to the receiver device, the storage, and the output device, the processor, responsive to the receiver detecting the theme identifier device and the action for dispensing the soap, selectively accesses and processes data of the storage representing the at least one of the plurality corresponding to the theme identifier device of the soap container, and controls the output device to deliver the at least one of the different human perceptible media corresponding to the theme identifier device of the soap container.
[0012] Yet another embodiment of the invention is a method of manufacture of a soap dispenser system for a soap user. The soap container has a thematic device and dispenses soap in response to an action of the user. The method includes providing a base for the soap container, providing a thematic detector for the base, the thematic detector capable of discerning the thematic device of the soap container when the soap container contacts the base, connecting a controller to the thematic detector, and connecting a device for human perceptible output to the controller, the device controlled by the controller to output a human perceptible media corresponding to the thematic device of the soap container.
[0013] Another embodiment of the invention is a method of manufacture of a media player base for a soap dispenser container. The soap dispenser container includes a type identifier. The method includes providing a circuit to control an output media corresponding to the type identifier, connecting a detector of the type identifier to the circuit, connecting a sensor to the circuit, and housing the circuit, the detector, and the sensor as a unit. The circuit controls the output media corresponding to the type identifier, responsive to the detector based on the type identifier and to the sensor when soap is dispensed by the soap dispenser container.
[0014] Yet another embodiment of the invention is a method of manufacture of a media player base for a plurality of different soap dispenser containers. Each of the plurality of soap dispenser containers includes a unique type identifier. The method includes providing a circuit to control a plurality of unique output media, each respective one of the plurality of unique output media corresponds to a respective one of the unique type identifier, connecting a detector to the circuit, the detector uniquely identifies each respective one of the unique type identifier for the circuit, connecting a sensor to the circuit, the sensor detects for the circuit when soap is dispensed from one of the plurality of soap dispenser containers then uniquely identified by the detector, and housing the circuit, the detector, and the sensor as a unit. The circuit controls delivery of the unique output media corresponding to the unique type identifier for the one of the plurality of soap dispenser containers, responsive to the detector based on the unique type identifier and to the sensor when soap is dispensed by the soap dispenser container.
[0015] Another embodiment of the invention is a method of washing. The method includes placing a soap dispenser container having a type identifier on a media player base, detecting by the media player base the type identifier, detecting by the media player base that soap is dispensed from the soap dispenser container, and outputting by the media player base a select human perceptible media in response to the step of detecting the type identifier and detecting that soap is dispensed, the select human perceptible media corresponds to the type identifier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention is illustrated by way of example and not limitation in the accompanying figures, in which like references indicate similar elements, and in which:
[0017] FIG. 1 illustrates a cross section of a soap dispenser base with a male attachment for mating with a bottle of soap, according to certain embodiments of the invention;
[0018] FIG. 2 illustrates a cross section of a bottle of soap with a female attachment suitable for mating with the male attachment of the soap dispenser base of FIG. 1 , according to certain embodiments of the invention;
[0019] FIG. 3 illustrates a top down view of the base of FIG. 1 showing a non-symmetrical shape of the male attachment and lights on a surface of the base, according to certain embodiments of the invention;
[0020] FIG. 4 illustrates a block functional schematic of an exemplary control system for controlling audible sound and visual light elements of the base of FIG. 1 , according to certain embodiments of the invention;
[0021] FIG. 5 illustrates a flow diagram of a process of an exemplary operation of the base of FIG. 1 in use during hand washing, according to certain embodiments of the invention;
[0022] FIG. 6 illustrates a system of a media player base for a soap dispenser bottle, according to certain embodiments of the invention; and
[0023] FIG. 7 illustrates a high level functional unit representation of a controller of the media player base of FIG. 6 , according to certain embodiments of the invention.
DETAILED DESCRIPTION
[0024] Referring to FIG. 6 , a system 600 includes a media player base 602 and a soap dispenser bottle 604 (shown in phantom). The soap dispenser bottle 604 is interchangeable, and may be replaced with other soap dispenser bottles. The media player base 602 , however, is reusable for various dispenser bottles. For example, soap dispenser bottles are often consumables that are replaced when soap contents are depleted. The base 602 , therefore, is usable with replacements of the soap dispenser bottle 604 as will be further discussed.
[0025] The soap dispenser bottle 604 contains soap 606 and includes a dispenser pump 608 of the type which may be pressed with downward (in FIG. 6 ) force to dispense the soap 606 . The dispenser bottle 604 includes an identifier device 610 . The identifier device 610 is included as part of the bottle 604 and is detectable by the base 602 when the bottle 604 is located sitting atop the base 602 . The identifier device 610 is unique to the particular type of the bottle 604 , and the correspondence of the identifier device 610 with particular type of the bottle 604 will be later further addressed.
[0026] Continuing to refer to FIG. 6 , the base 602 provides a stable support under the bottle 604 when the bottle 604 sits on the base 602 . The base may sit on a countertop, sink surface, or other generally horizontally disposed plane (not shown in FIG. 6 ), and the bottle 604 is located atop the base 602 in use. The base 602 includes a detector device 612 (shown in phantom) for discerning the identifier device 610 of the bottle 604 when the bottle 604 is placed atop the base 602 . The base 602 also includes a media player device 614 (shown in phantom) connected to the detector device 612 .
[0027] In operation, the base 602 is located on a support surface and the bottle 604 is placed on the base 602 . When the bottle 604 is placed on the base 602 , the detector device 612 of the base 602 discerns the identifier device 610 of the bottle 604 . The media player device 614 of the base 602 , in response to the discerned identifier device 610 of the bottle 604 , commences operations selective to the identifier device 610 and, thus, the particular type of the bottle. The identifier device 610 , because corresponding to the particular type of the bottle 604 , allows the media player device 614 to selectively operate for the bottle 604 , and its particular type.
[0028] According to certain embodiments, for example, the bottle 604 can have a type that corresponds to a particular scheme or theme, such as that of a particular animal, event, person or other thing recognizable to a person who will wash with the soap 606 dispensed from the bottle 604 . In the case of a particular scheme or theme for any bottle, the bottle may include particular visible decorative indicia or emblem, shape of the bottle, color of the bottle or soap, and/or others. As a more specific exemplary possibility (among a wide variety of alternatives) for type of the bottle, the bottle may be dinosaur themed. Such dinosaur themed bottle may contain green soap and a decorative emblem of a dinosaur on the bottle. Because the identifier device 610 of the bottle 604 corresponds to the type and thus theme of the particular bottle, the detector device 612 of the base 602 can discern the identifier device 610 and then operate in accordance with the type and theme of the particular bottle.
[0029] The media player device 614 of the base 602 , for example, includes or communicatively accesses data representing audible sounds, such as animal sounds which may include the sound of a dinosaur. The media player device 614 accesses particular data, and thus a particular sound is produced, corresponding to the identifier device 610 discerned by the detector device 612 . According to certain embodiments, the media player device 614 includes (not shown in FIG. 6 ) a processor, data storage or memory, and sound output device connected to a power source.
[0030] When any particular type of the bottle 604 contacts the base 602 , such that the identifier device 610 of the bottle 604 indicative of particular bottle type is discerned by the detector device 612 of the base 602 , the media player device 614 of the base 602 commences operating responsive to the particular identifier device (and therefore particular bottle type). When any different particular type of the bottle 604 (with different identifier device) instead contacts the base 602 (and the detector device 612 discerns the different identifier device), the media player device 614 of the base 602 commences differently operating in response to the different identifier device and therefore different particular type of the bottle 604 .
[0031] Referring to FIG. 7 , although FIG. 7 shows a particular illustration, the illustration is intended and should be understood merely as a higher level functional block or unit representation of functional elements of a controller 700 of the base. Therefore, each specific element of the controller 700 should be understood as a functional unit or block in nature, and not necessarily as any particular electronic component or apparatus even if illustrated as such for purpose of explanation.
[0032] Continuing to refer to FIG. 7 , in conjunction with FIG. 6 , the controller 700 of the media player base 602 comprises the detector device 612 and the media player device 614 . A power source 702 is connected to a first switch 704 . The first switch 704 remains open unless and until closed by dispensing the soap 606 from the bottle 604 for washing, for example, the first switch 704 closes (and connects the power source in closed circuit in the controller 700 ) only when a pumping force is made on the dispenser pump 608 of the bottle 604 to dispense soap 606 when the bottle 604 sits on the base 602 .
[0033] As an alternative to a pumping force used to close the first switch 704 , it is possible to utilize a touch free soap dispenser system to trigger output of audible sound or other human perceptible media by the base or other configuration of components in similar to those of the system. One example of such a touch free dispenser system with the ability to utilize multiple refill bottles is the Lysol™ No-Touch Hand Soap system.
[0034] The first switch 704 is connected to three identification switches 706 a , 706 b and 706 c . Each of the identification switches 706 a , 706 b , 706 c connects to a processor (or logic circuit) 708 . The identification switches 706 a , 706 b , 706 c in combination with the processor 708 are an example of the detector device 612 . In the example, a particular type of the bottle 604 may have an identifier device 610 that closes identification switch 706 c , but not identification switches 706 a or 706 b . Per the example, the closed identification switch 706 c instigates particular processing by the processor 708 corresponding to the particular identifier device 610 of the bottle 604 (and consequently the particular type of the bottle). A different bottle might, for example, have a different identifier device that closes identification switch 706 a , but not identification switches 706 b or 706 c . In such instance, the processor 708 accordingly processes differently to correspond to the different identifier device (and thus different type of the bottle).
[0035] The processor 708 is connected to one or more human detectable output devices, for example, a speaker 710 and/or one or more lights 712 a , 712 b , such as LED or other lights. The output devices, for example the speaker 710 and lights 712 a , 712 b , or some or all of these devices, are connected to an output switch 714 connected to or included in the processor 708 . The output switch 714 is controlled by the processor 708 for on and off operation of the output devices, or certain of them, and may additionally provide rectification, amplification or other function.
[0036] The processor 708 includes or accesses one or more timing device and memory or other data storage (not shown in detail in FIG. 7 ). Data representing one or more audible sounds and/or other human perceptible media is stored in the memory/storage. The memory/storage also holds data representing one or more control logic sets for control of timing and output from the output devices.
[0037] In operation, when the switch 704 closes in response to a user dispensing the soap 606 from the bottle 604 via the pump 608 , the identifier device 610 of the particular type of the bottle 604 then in contact with the base 602 triggers one of the identification switches 706 a , 706 b or 706 c closed. The processor 708 discerns which of the identification switches 706 a , 706 b or 706 c thereby is closed, and commences processing data representing about a 20 to 30 second period of audible sound for output by the speaker 710 . Additionally, the processor 708 may process data representing state of the lights 712 a , 712 b for on or off control during the 20-30 second period of audible sound or otherwise. In effect, the processor 708 controls output of the speaker 710 and lights 712 a , 712 b providing about 20-30 seconds of audio sound and lighting after soap is dispensed. Alternately, time periods for output may be longer, shorter or otherwise. In other alternatives, sound may be output only after 20 seconds (or some other desired period) whereas lights may be powered on for the 20 seconds (or other period) prior to the sound output. Of course, numerous variations are possible in these outputs and control by the processor 708 , in view of the type of the bottle and identifier device and the capability of the base to detect the bottle type thereby and deliver human perceptible output as provided by the base. Also, because different bottles (with different identifier device) may have different themes, output by the base can be coordinated with the particular theme for each particular different bottle.
[0038] As described in connection with FIGS. 6-7 , the identifier device 610 , the detector device 612 , and the functional unit representation of the controller 700 provide generalities of embodiments. Certain examples according to the foregoing general embodiments follow:
Examples
[0039] Referring to FIG. 1 , a soap dispenser base 11 comprises two major sections. A lower section 12 is designed to sit on a surface where one might find a soap dispenser (e.g. a counter top). An upper section 21 is capable of attaching to and sitting on top of the lower section 12 such that the lower section 12 and the upper section 21 fit together to form the base 11 . The upper section 21 is attached to the lower section 12 by sliding engagement in such manner that the upper section 21 is capable of moving up and down (over a small gap extent “A”) in relation to the lower section 12 in attachment thereto. A biasing device 14 keeps the upper section 21 in a normally raised position in sliding engagement vis-à-vis the lower section 12 , such that the gap extent “A” exists between portions of the upper section 21 and the lower section 12 . The biasing device 14 can be any of a large number of well known biasing mechanisms or components such as, for example, springs, foam, elastomers, O-rings and/or others.
[0040] Referring to FIG. 2 , in conjunction with FIG. 1 , a soap dispenser bottle 31 is capable of being detachably attached to the upper section 21 of the base 11 . As a pump 32 on the bottle 31 is depressed to get liquid soap from the bottle 31 , the pumping action on the dispenser bottle 31 applies downward pressure force on the upper section 21 of the base 11 . Further, the downward pressure force on the upper section 21 puts pressure on the biasing device 14 which in turn overcomes the upward bias and moves the upper section 21 downward relative to the lower section 12 , to close the small gap extent “A” (closed gap extent not shown in FIG. 1 ) when the base 11 with bottle 31 is positioned stationary on a counter top or other surface or the like.
[0041] The lower section 12 includes an appendage 13 . The appendage 13 is raised above the upper surface (in the illustration of FIG. 2 ) of the lower section 12 . Further the bottom surface (in the illustration of FIG. 2 ) of the upper section 21 may include a switch mechanism 22 that is directly above the appendage 13 when the upper section 21 is connected in sliding engagement with the lower section 12 . The appendage 13 and the switch 22 are placed and sized such that the appendage 13 does not touch the switch 22 because of the gap extent “A” maintained by the biasing device 14 when the bias is not overcome by sufficient downward pressure force applied to the upper section 21 to overcome the upward bias of the bias device 14 . The bias device 14 sufficiently biases the upper section 21 slidingly extended upward in attachment with the lower section 12 maintaining the gap extent “A” between the appendage 13 and the switch 22 when the soap bottle 31 sits in connection atop the base 11 full of soap (but without downward force for dispensing soap asserted on the pump 32 of the bottle 31 ). The upward bias of the upper section 21 vis-à-vis the lower section 12 maintains the switch 22 above and not in contact with the appendage 13 . However, the upward biasing from the bias device 14 is overcome when a downward pumping action is made by a user on the pump 32 to dispense soap. This downward pumping action exerts downward pressure force against the bottle 31 and consequently against the upper section 21 , thereby forcing the upper section 21 to slide downward in attachment to the lower section 12 to close the gap extent “A” and contact the switch 22 to the appendage 13 .
[0042] In certain alternatives, the appendage 13 is not necessary if the switch 22 extends downward (in the illustration of FIG. 2 ) far enough below the other portions and components of the upper section 21 to allow the switch 22 , but not other functional portions of the upper section 21 (as later described), to contact the lower section 12 when the upper section 21 slides downward against the bias closing the gap to the lower section 12 .
[0043] A standard soap bottle typically may weigh about 2 lbs or less and the amount of pressure force needed to activate a typical soap dispenser pump is on the order of about 5-7 pounds of pressure force. This difference between the weight of a full soap bottle and the pressure needed to pump soap allows for a large variety of biasing approaches and mechanisms. In certain alternatives, the separate biasing device 14 may not be necessary, for example, the upper section 21 can be made of a flexible material that flexes down when downward pressure is exerted on it but then flexes back when the pressure is removed.
[0044] Referring to FIG. 4 , in conjunction with FIG. 1 , a control system 40 of the base 11 , such as, for example, an electronic circuit of electrical elements and connections, may be included in the upper section 21 (or, although not shown in FIGS. 1 and 4 , may otherwise be communicatively connected to the upper section 21 ). The control system 40 includes the switch 22 . The switch 22 can be any of a large number of different types of switches such as contact switches, micro-electro-mechanical switches, pushbutton, toggle, slide, as well as other switches. The switch 22 is operative to switch “on” (close the circuit 40 ) when the switch 22 contacts the appendage 13 and to switch “off” (opening or shorting the circuit 40 ) when the switch 22 is not in contact with the appendage 13 for some period of time, such as, for example, from after about 20-30 seconds after contact is made to switch “on” or other time period as desired in the embodiment. Timing for switching by the switch 22 can be controlled by the processor 27 or another timer (not shown in FIG. 4 ) of the system 40 , and alternately the switch 22 can comprise mechanical timed switching or other timing for switching as will be understood by those skilled in the art. In the embodiments, the switch 22 , for example, operates to switch “on” power by closing the circuit of the system 40 when the switch 22 contacts the appendage 13 and the switch 22 thereafter remains “on” (closed circuit) for a desired period after the contact, such as for about 20-30 seconds.
[0045] The switch 22 is communicatively connected to a power source 23 and a processor 27 . The power source 23 may be a battery (e.g. a nine volt standard battery or other battery) or another electrical source such as a direct or alternating current power supply, and the system 40 may include transducer, regulator, and/or other components as may be desired for powering the processor 27 and other components of the system 40 . The processor 27 is communicatively connected to a speaker/transducer 28 , a memory component 29 and one or more bottle identification button 26 a , 26 b and 26 c . The speaker/transducer 28 is capable of outputting an audible sound, for example, an animal sound or music, responsive to the processor 27 and power from the power source 23 . The memory component 29 , which may be included in the processor 27 or communicatively connected to the processor 27 , stores data representing one or more of the audible sounds for selective output by the speaker/transducer 28 under control of the processor 27 . The one or more bottle identification button 26 a , 26 b , 26 c each provide a switch or flag input to the processor 27 for controlling processing operations of the processor 27 .
[0046] Referring to FIG. 5 , a method 50 is performed by the base 11 when the bottle 31 is attached and downward pumping force is applied to the pump 32 for dispensing soap. In a step 51 , the switch 22 is triggered to “on” closing the circuit connecting the power source 23 to the processor 27 . In a step 52 , the processor 27 then commences processing for controlling the speaker/transducer 28 and the memory component 29 , in response to state of the button 26 a - c . In a step 53 , the processor 27 detects which, if any, of the bottle identification buttons 26 a , 26 b or 26 c have been pushed (i.e., depressed, selected or otherwise activated by attachment of the bottle 31 ). In response to the step 53 , the processor 27 in a step 54 (accesses from the memory 29 , if necessary, and) processes data representing applicable media for output by the speaker/transducer 28 . The particular data processed in the step 54 represents particular media selected according to state of the button 26 a - c detected in the step 53 . For example, in certain embodiments, the processor 27 in the step 54 processes data representing a song for delivery to the speaker/transducer 28 and, in a step 55 , the processor 27 controls the speaker/transducer 28 to output for about 20 to 30 seconds an audible sound of the song. In alternative embodiments, the processor 27 in the step 54 processes data representing the song for delivery to the speaker/transducer 28 , however, the processor 27 in the step 55 controls the speaker/transducer 28 to only output the audible sound of the song after about 20-30 seconds has passed from commencement of the step 51 .
[0047] Referring back to FIGS. 1-3 , in conjunction with FIGS. 4 and 5 , the identification buttons are automatically pushed (only one a time) when the bottle 31 is placed on the base 11 by aligning a male attachment 41 of the upper section 21 of the base 11 with a female attachment 33 on the underside of the bottle 31 . The male attachment 41 can snap into the female attachment 33 , such as, for example, via a lip 25 on the male attachment 41 and a corresponding channel 34 on the female attachment 33 (this snapping mechanism can be reversed such that the lip is part of the female attachment means). A wide variety of mechanisms and components are possible for detachably attaching the bottle 31 to the base 11 as will be apparent to those skilled in the art.
[0048] When the bottle 31 is placed on the base 11 with the male attachment 41 inserted into and snapped onto the female attachment 33 , a bottle appendage 35 protruding from the female attachment 33 is located such that, as an example (as illustrated in FIGS. 1 and 2 ), the appendage 35 pushes the button 26 a . When the base 11 is activated by someone pushing downward the pump 32 of the soap bottle 31 , the processor 27 detects that button 26 a has been depressed and signals the speaker/transducer 28 to produce audible sound at the end of 20 seconds (or other desired period) from the time that the switch 22 first contacts the appendage 13 , for example, producing the sound of a dinosaur roaring after 20 seconds (or other period).
[0049] When another type of soap bottle is placed on base 11 (e.g., a pony themed soap bottle rather than a dinosaur themed bottle), the appendage 35 is located in a different position (not shown in detail in FIG. 2 ) relative to the male attachment 41 of the base 11 . This different position of the appendage 35 causes the appendage 35 to push, for example, bottle identification button 26 b when downward force is applied to the pump 32 of the soap bottle 31 . In this case of a differently themed bottle of soap (with different male attachment 41 position) on the base 11 , the processor 27 , when operative because of contact of the switch 22 with the appendage 13 , detects that bottle identification button 26 b is depressed. In response to detecting depression of the button 26 b , the processor 27 directs the transducer/speaker 28 to make a different audible sound after 20 seconds (or other desired period in the embodiment), for example, an audible neigh sound of a pony. In various alternatives, the processor 27 can have respective data file(s) representing the various audible sounds stored in the processor itself (such as in memory component or other storage of the processor 27 ), or the respective data file(s) representing the audible sounds may be stored on the memory component 29 , another storage communicatively connected to the processor for such sounds, or otherwise. The memory component 29 in certain alternatives may also be controlled by the processor 27 to program record(s) of usage of the base 11 , to provide feedback, such as by audible output of the speaker/transducer 28 or output report, about hand washing usage and trends, and to allow loading of additional data file(s) representative of sounds, alternative functions, or other features, or attachment of additional or ancillary components or elements, for example, visible clock, error reporter, soap level indicator, visual display, and/or others.
[0050] In certain embodiments of the invention, audible feedback from speaker/transducer 28 may provide not only entertainment but may teach. For example, when triggered, the speaker/transducer 28 in certain embodiments is controlled by the processor 27 to play the ABC song (from data representing the song stored in memory, other storage, or otherwise generated) for the entire 20 seconds (or other desired period) of hand washing and, once 20 seconds (or other period) has passed, stops play of the song. This teaching capability may be of great interest to parents trying to educate children. In another example, a Spanish themed soap dispenser may trigger a base that aids a child to learn Spanish as they wash their hands, for example, through play for about 20 to 30 seconds of a Spanish tutorial for children output by the speaker/transducer 28 as controlled by the processor 27 . In other examples, the base 11 could include in memory various data files representing different educational information that cycles through as the base triggers the processor 27 to control output of the speaker/transducer 28 in response to depression of the soap dispenser. This could also be used by adults, in order to learn new languages, or skills. As can be understood, a wide variety of content can be stored as data files in memory and processed by the processor 27 as output of the speaker/transducer 28 or other device or display.
[0051] In order to assure that appendage 35 on bottle 31 is oriented correctly vis-à-vis the bottle identification buttons 26 a , 26 b and 26 c , the male attachment 41 and the female attachment 33 in certain embodiments are each shaped in a non-symmetrical manner, so that the bottle 31 must be selectively oriented for placement on the base 11 for attaching the male attachment 41 and the female attachment 33 . Referring to FIG. 3 for an example of non-symmetrical shapes, the base 11 includes an irregularly shaped male attachment 41 . A corresponding female attachment 33 on the bottle 31 must be similarly shaped for attaching the bottle 31 with the base 11 . This assures that the bottle 31 is selectively oriented in location in connection to the base 11 . This further assures that the appendage 35 (shown in FIG. 2 ) can properly depress a select bottle identification button 26 a , 26 b , or 26 c that is intended for the particular bottle 31 (i.e., this assures that the base 11 provides the applicable audible noise when triggered for the particular bottle 31 , such as, for example, when the bottle 31 has particular theme and a corresponding sound for that theme applies).
[0052] In addition to triggering audible timing prompts as discussed above, in certain embodiments of the invention, the processor 27 communicatively connects to lights 24 a and 24 b , for example. These lights 24 a , 24 b can be positioned for external viewing in the top of the base 11 and directed into the bottle 31 when positioned on the base 11 . The lights 24 a and 24 b in certain embodiments are controlled by the processor 27 to emit on when the pump 32 is pressingly pumped, and then to turn emission off 20-30 seconds later. This allows a hand washing user to know that the base 11 is working properly. It also can result in some entertaining or interesting visual effects in the soap itself in certain embodiments. It is not necessary that the lights be pointed up into the soap, however; in some embodiments lights are included in a side of the base 11 . Such arrangement of lights, for example, provides user information about operability of the base 11 , such as that the base 11 is active for operation when the lights are on. In other embodiments, lights can provide additional signal(s) of hand washing timing, such as could be especially useful for those unable to discern audible sounds or for aiding stimulation of the user through other features of the base 11 . In certain alternatives, a top surface of the base 11 is transparent and lights 24 a and 24 b are not on the top surface of base 11 but instead are located underneath the transparent surface of the base 11 .
[0053] Although the base 11 and its operation during hand washing have been described, the base 11 can alternatively be provided with similar or additional elements, components or connectors for other wash or dispensing situations. For example, the base 11 , if incorporated with or communicatively connected to appropriate output devices, can provide a wide variety of output from the base initiated upon dispensing action. For example, other visual, audio, video, media or report outputs can be delivered from the base, either to components incorporated in the base or to external communicatively connected components. In certain alternatives, additional switch or control mechanisms may be included in the base or otherwise in embodiments, for example, a switch may be included to allow selective turn “off” of sound output or other features (such a mechanism may be desirable to parents, in particular, in embodiments for use by children). In other alternatives, the base and the soap bottle or other soap vessel may be contained within an enclosure or be connected by attachment mechanisms that prevent unauthorized disengagement of the base and bottle or vessel. Such base and soap bottle or vessel combination may be targeted for washing by restaurant employees or others in food, drug, medical, or other environment where non-contamination, cleanliness, and effective washing is important. Because sounds, lights, and other output of the base can be varied for an applicable target audience of washing users, a communication port or other device can be included in the base for varying operations and output. For example, soap of the dispenser having suspended air bubbles can be illuminated via lights of the embodiments, providing dramatic lighting effects in the soap as the light bounces off of the bubble interfaces. All variations of designs, configurations, output elements, shapes, circuits, and devices therefor, as may be applicable for target use, target user and environment of use, are within the scope of the foregoing.
[0054] In the foregoing specification, the invention has been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention.
[0055] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems and device(s), connection(s) and element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. As used herein, the terms “comprises, “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
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A soap dispenser system for dispensing soap in response to a user's action, such as pumping force to a dispenser pump of a soap container. The soap container has a theme identifier device corresponding to the soap container. A supportive base detachably connects to the soap container. The base includes a receiver device for detecting the theme identifier device of the soap container when the soap connector is connected to the base. A readable data storage is connected to the receiver device. The storage contains data representing a variety of different human perceptible media, such as audio (e.g., animal, people, or musical sounds). At least one of the variety of media corresponds to the theme identifier device of the soap container. An output device delivers the media to a user of the soap container. A processor connected to the receiver device, the storage, and the output device responds to the receiver detecting the theme identifier device and dispensing action by a user to obtain soap from the container. The processor selectively controls the output device to deliver specific media (from among the variety) to the user corresponding to the theme identifier device of the soap container. The system can encourage frequent and efficacious washing. The media encourages washing for recommended wash times, for example, the system delivers 20-30 seconds (or such other period as desired for the particular embodiment) of animal sounds for entertainment and measure of recommended wash time when an animal themed soap container is used.
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SUBJECT MATTER OF INVENTION
The present invention relates to improvements in a urinary incontinence collector for use by those who are incapable of controlling voiding.
BACKGROUND OF INVENTION
The inability to retain urine affects a large number of people of all ages of both sexes. The inability to control one's bladder may create problems for many people under a variety of circumstances. For example, a businessman at a board meeting, travellers, jurors, and many others are placed under very embarrassing conditions if they cannot retain urine even for a short time. There have been a number of efforts to provide suitable devices of this type. However, insofar as I am aware, none suggest the features disclosed and claimed herein. These efforts are exemplified in the following United States patents: U.S. Pat. Nos. D 281,270; D 275,600; D 258,682; D 244,403; D 240,132; D 233,889; D 222,062, O; 4,060,859, X; 4,571,241, X; 4,496,355; 4,304,013; 3,680,543;D 283,922; D 282,489; D 279,605; D 277,410; D 273,709; D 264,133;D 248,168; D 245,543; D 244,403; 3,207,155; 3,636,953; 4,195,630; 4,205,679.
SUMMARY OF INVENTION
Accordingly, it is an object of the present invention to provide an improved urinary incontinence collector that is easy to wear, inconspicuous in appearance and which will function effectively to prevent uncontrolled urinary discharge on one's clothing.
A further object is to provide a collector useful by both male and female that is easily removed, cleaned, and replaced.
A further object is to provide a urinary collector which is particularly suitable for individuals having mild urinary problems as well as those subject to a more serious uncontrolled flow accomplished free of skin wetness and odor.
The assembly consists of a pair of bags, preferably made of thin plastic, joined together below the groin and between the thighs. A front piece of double walled web and a rear v-shaped strap are fastened to a waist band to support the pair of bags. Fastened to the rear wall of the web and partially supported by the rear strap, is a member designed as to accommodate both sexes. This member includes a soft, flexible ring at the periphery of an oval-shaped opening to provide sealing against the urinary orifice. A catch pad of permeable spongy substance is positioned within the double wall which is accessable through a zipper fastener opening. This pad is replaceable and washable as are all other components of the device, except a provided changeable seat pad. A one-way hinged flap in the oval opening serves as a directional valve. In normal position, it stays open; in instances where there is a reverse flow of liquid due to position of wearer, the sensitive valve flap is forced against a spongy seat by the force of the liquid. Any seepage is absorbed by the catch pad. Each bag is provided with a thigh fastening band which is adjustable and stretchable as is the waist band. In essence, a chamber is created such that when worn, the passage of urine is restricted to that chamber (including the related bags) and does not permit the wetness on the exterior or on the wearer.
DESCRIPTION OF DRAWINGS
The foregoing objects and features of the present invention will be better understood from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of a urinary incontinence collector according to the present invention with a torso indicated in dotted outline.
FIG. 2 is a rear fragmentary perspective view of the urinary incontinence collector of FIG. 1, illustrating the various assembly features of the present invention.
FIG. 3 is a front partially sectioned view of the urinary incontinence collector illustrating the various components and features of the present invention.
FIG. 4 is a side elevational partial cut-away of the urinary incontinence collector, of FIG. 3 illustrating further assembly features of the invention.
FIG. 5 is a fragmentary sectional side view of the urinary incontinence collector, illustrating the valve features and function, and
FIG. 6 is a partial cut-away perspective view of the urinary incontinence collector, illustrating the valve features of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present urinary incontinence collector assembly comprises a pair of bags 10 and 11, the double-walled web 12, waist band 14 secured to the web 12 by loops 16 and 18, and rear support strap 20.
The waist band 14 may be made of suitable fabric and should be adjustable in length. This may be achieved by providing the free ends of the waist band 14 with an appropriate closing mechanism such as the conventionally well known Velcro fastening system 21. The double-walled web 12 consists of a rear wall 22 and a front wall 23. A zipper fastener 24 in the front or forward wall 23 provides a lateral opening for access to the interior of the double-walled 12. The rear wall 22 of the web is formed with an orifice or opening 26 that is bordered by an annular gasket 28 of resilient, cushioning material that is adapted to press firmly against the wearer's groin in an area enclosiong the urinary opening. A highly absorbent fibrous pad 30 is positioned between the rear and front walls 22 and 23. This fibrous, absorbent pad faces the opening 26 and provides a fluid absorbent medium. An opening 32 appropriately located within the orifice or opening 26 functions as a penis outlet.
The upper ends of the bags are supported by a web 35 that is secured to the inner surface of front wall 23. Openings are provided to permit the passage of fluid from between the forward and rear walls 22 and 23 into one or both of the bags 10 and 11. Each of the bags 10 and 11 are provided with a valve mechanism best illustrated in FIG. 5. This valve mechanism (as also illustrated in FIG. 6) consists of a rectangular frame 36 to which a flap 37 is hingedly attached and a plastic strap 38 that serves to support and retain the valve flap 37 in the open position shown. The rectangular frame 36 may be either or one homogeneous but resilient material, or semi-rigid with the seating area of the base being resilient.
The sensitiveness of the hinge is attributed to an extremely flexible thin plastic film in the order of 0.003" thick. Said hinge may consist of two (or more) extended strips as shown in FIG. 6 or of a continuous extended strip.
Gravity normally permits a downward movement of the flap 37 in the manner best indicated in FIG. 5. Partial closure, due to position of wearer, has virtually no effect on proper flow operation by virtue of the space above the valve, absorbing characteristic of pad 30 and the sensitivity of the flap hinge. Likewise, a reverse flow will cause the flap 37 to close and any seepage would be absorbed by the pad 30.
The valve member can be bonded in place in a bag. A protrusion 39 facilitates positioning.
The bags 10 and 11 are each provided with straps 40 and 41. These straps are designed to wrap around the wearer's leg at the thigh region to secure the bags 10 and 11, one to each leg. Suitable means such as Velcro fasteners may be provided on the facing surfaces of the straps.
The rear straps 20 may be integrally formed with the belt 14 at their upper end and commonly joined at the lower end to the rear edges of the bags 10 and 11. These straps are adapted to extend over the wearer's buttocks and are designed to secure the double walled web 12 in secure engagement with the groin of the wearer. A pad 44 of absorbent material is provided at the junction of the belts 20.
The various components of this device may be made of suitable non-permeable material except for the absorbent portions. A suitable material is a polyester, but other acceptable plastics may also be used. The fibrous pads 30 and the pad 44 are both removeable, with pad 44 designed for regular replacement. A suitable mechanism may be provided for securing pad 44 to the junction of straps 20. Such a mechanism may comprise a Velcro fastener.
A suitable draining means, as shown in FIG. 4, consists of an elastomer protrusion 46 at a base corner of each bag with an associated quick and easy plastic clamp means 48 permanently attached to the protrusion or protuding tube 46.
While the present invention contemplates in its embodiment the use of Velcro (TM) fasteners, other fasteners may also be used.
The foregoing describes a preferred embodiment of the present invention. However, appropriate variations may be effected within the scope of the present invention. Thus, for example, the present invention embodies converting the device from one that is useful for members of either sex to one that is useful primarily for females simply by the elimination of the penis hole.
Another embodiment is to make available a suitable layer of material to avoid direct contact of wearer's skin to the plastic bag in consideration of those who may be conducive to skin rash or other irritation. Quick and easy attachment with Velcro could be relied on as in other aforestated cases.
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The present application discloses a wearable urinary incontinence collector. It consists of a pair of bags designed and shaped to be worn on the inside thighs of an individual appropriately strapped to the legs. A frontal web covers the groin area and supports the bags in connection with a suitable array of straps. The arrangement is virtually leak-proof and inconspicuous when worn while standing, sitting, or lying.
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FIELD OF THE INVENTION
The present invention relates to a battery electrode material and a preparation method thereof, particularly a silicon-carbon composite anode material for lithium ion batteries and a preparation method thereof.
BACKGROUND ART
Current commercial anode materials for lithium ion batteries mainly use graphite. However, theoretical specific capacity of graphite is only 372 mAh/g, which can not meet the development requirements of the new generation of high-capacity lithium ion batteries. Silicon has the highest theoretical lithium storage capacity (4200 mAh/g) and a low lithium deintercalation voltage platform (about 0.4V), thus it is the most potential new anode material for lithium ion batteries to replace graphite. However, in the charge-discharge process, silicon exhibits significant volume change, which leads to pulverization of the material particles and the destruction of conductive network within the electrode, limiting its commercial applications. In addition, the intrinsic conductivity of silicon is very low (only 6.7×10 −4 Scm −1 ), thus it is not suitable for high current charge-discharge. On the other hand, the carbon-based material has a small lithium intercalation and deintercalation volume effect and high conductivity. The combination of silicon and carbon can effectively alleviate the volume effect of silicon, reduce the electrochemical polarization, and increase charge-discharge cycling stability. Chinese Patent application CN200510030785.8 discloses a lithium ion battery silicon/carbon/graphite composite anode material, which is prepared by a concentrated sulfuric acid carbonation method. This material consists of elemental silicon, graphite particles and amorphous carbon and does not have a porous structure. Its initial lithium deintercalation capacity is about 1000 mAh/g, but after 10 charge-discharge cycles, the capacity is attenuated by about 20%. Thus, its charge-discharge cycling stability is not good.
To further alleviate the volume effect of silicon, a silicon material having a porous structure is designed. Its internal pore volume reserves space for the volume expansion of silicon, the macroscopic volume change of the lithium storage material is reduced, the mechanical stress is relieved, thus the structural stability of the electrode is improved.
Chinese patent ZL200610028893.6 discloses a copper-silicon-carbon composite material having a nano-porous structure. It is prepared by a high-energy ball milling process. The pore size is 2 to 50 nm, the copper content is about 40 wt %, and the carbon content is about 30 wt %. The material shows a good charge-discharge cycling stability, but its reversible capacity is low, which is only about 580 mAh/g.
PCT/KR2008/006420 discloses a silicon nanowire-carbon composite material having a mesoporous structure. It is produced through an alumina template method. The silicon nanowire has a diameter of 3 to 20 nm, the diameter of the mesopore is 2 to 20 nm, and the carbon content is 5 to 10 wt %. The material has a charge-discharge capacity of 2000 mAh/g at the rate of 1 C. The cycling stability is better, but the process is complex, thus it is difficult to realize industrial production.
Angewandte Chemie International Edition, 2008, Issue 52, pages 10151-10154 reports a three-dimensional macroporous silicon-based material. Firstly, silicon tetrachloride is reduced with sodium naphthalene and butyl lithium is introduced therein to produce butyl-encapsulated silicone gel, followed by the addition of silica particles as a template, and then carbonization is carried out by heat treatment, finally the material is caustic etched by hydrofluoric acid, a macroporous silicon material is thus obtained. The macroporous silicon is of a single crystalline structure, whose average particle diameter is 30 μm or above, and the pore size is 200 nm. The reversible capacity of the material at the rate of 0.2 C is 2820 mAh/g, the cycle performance is good. However, its synthesis process is cumbersome, and a large amount of strongly corrosive and highly dangerous chemical reagents are necessary. The waste would affect the environment, and the production cost is high. Thus, it is not suitable for large-scale industrial applications.
Advanced Materials, 2012, Issue 22, pages 1 to 4 reports a macroporous silicon silver composite material. Firstly, elemental silicon having a three-dimensional macroporous structure is prepared by magnesium thermal reduction, then silver nanoparticles are deposited in the macro pores by silver mirror reaction, the silver content is 8 wt %. The macroporous silicon is of a single crystalline structure, its particle size is 1 to 5 μm, and the pore size is about 200 nm. Its initial lithium deintercalation capacity is 2917 mAh/g, and after 100 cycles, the deintercalation capacity remains above 2000 mAh/g. However, the use of silver would substantially increase the cost of production of the material, which is adverse to its industrial application.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a silicon-carbon composite anode material for lithium ion batteries and a preparation method thereof The silicon-carbon composite anode material of the present invention has high capacity, excellent cycle stability and rate performance. The method for preparing the silicon-carbon composite anode material of the present invention is simple, low cost, and suitable for industrial production.
The structure of the silicon-carbon composite anode material for lithium ion batteries consists of a porous silicon substrate and a carbon coating layer, wherein the carbon coating layer accounts for 2 wt % to 70 wt %, it consists of amorphous carbon and has a thickness of 2 nm to 30 nm; the porous silicon substrate is of a polycrystalline structure, the particle size is 50 nm to 20 μm, the pore size is 2 nm to 150 nm, the pore volume is 0.1 cm 3 /g to 1.5 cm 3 /g, and the specific surface area is 30 m 2 /g to 300 m 2 /g.
The silicon-carbon composite anode material for lithium ion batteries of the present invention has a porous structure, which can effectively alleviate the volume effect of silicon in the charge-discharge process. Moreover, a uniform carbon coating layer is present on the surface of the particles, while maintaining a high capacity, the cycle stability and high-current charge-discharge characteristics of the anode materials are improved. According to the present invention, the carbon coating layer accounts for 2 wt % to 70 wt %. If the weight percentage is less than 2 wt %, the content is too low to enhance conductivity and stabilize the structure. On the other hand, if the weight percentage is greater than 70 wt %, the content is too high; due to the low capacity of the carbon coating layer itself, the specific capacity of the composite anode materials would be greatly reduced. Further, since the present invention does not contain precious metals, the production cost can be significantly reduced.
The method for preparing the silicon-carbon composite anode material for lithium ion batteries of the present invention is as follows, the recited parts are by weight:
(1) preparation of porous silicon substrate
1 to 3 parts of mesoporous silica and 2 to 4 parts of magnesium powder are placed in a high temperature furnace; the temperature is raised to 600 to 900° C. in an atmosphere of a protective gas, and temperature is kept for 2 to 10 hours before it is allowed to cool; then the materials are put into 40 to 100 parts of hydrochloric acid with a concentration of 1 to 12 mol/L and stirred for 6 to 18 hours; after 3 to 5 times of centrifugation at 3000 to 10,000 r/min, and vacuum drying at 70 to 120° C. for 6 to 18 hours, a porous silicon substrate is obtained;
(2) carbon coating
the porous silicon substrate is placed in a high temperature furnace, where the temperature is raised to 600° C. to 1100° C. in an atmosphere of a protective gas; then a gaseous carbon source or a liquid carbon source is carried into the furnace by the protective gas, the temperature is kept for 1 to 12 hours; after the disassociation of the gaseous carbon source or the liquid carbon source, a carbon coating layer is formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries is obtained; or
the porous silicon substrate and a solid carbon source are dispersed in a solvent; the mixture are dispersed homogeneously by an ultrasonic treatment and stirring; then the solvent is evaporated, the material is transferred into a high temperature furnace where the temperature is raised to 600° C. to 1100° C. in an atmosphere of a protective gas, the temperature is kept for 1 to 12 hours; after the disassociation of the solid carbon source, a carbon coating layer is formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries is obtained.
The protective gas used in the present invention is selected from the group consisting of argon, nitrogen, helium, a gas mixture of argon and hydrogen, and a gas mixture of nitrogen and hydrogen, the content of hydrogen in the gas mixture being 2% to 20% by volume.
The gaseous carbon source used in the present invention is selected from the group consisting of acetylene, methane, ethane, ethylene, propylene and carbon monoxide.
The liquid carbon source used in the present invention is selected from the group consisting of benzene, toluene, xylene, ethanol, n-hexane and cyclohexane.
The solid carbon source used in the present invention is selected from the group consisting of polyvinyl chloride, polyvinylidene fluoride, polyacrylonitrile, polyvinyl alcohol, polystyrene, phenolic resins, epoxy resins, coal tar pitch, petroleum pitch, sucrose and glucose. The molecular weight of polyvinyl chloride is in a range of 50,000 to 120,000, the molecular weight of polyvinylidene fluoride is in a range of 250,000 to 1,000,000, the molecular weight of polyacrylonitrile is in a range of 30,000 to 200,000, the molecular weight of the polyvinyl alcohol is in a range of 20,000 to 300,000, the molecular weight of polystyrene is in a range of 50,000 to 200,000, the molecular weight of phenolic resin is in a range of 500 to 10,000, the molecular weight of epoxy resin is in a range of 300 to 8000.
The solvent used in the present invention is selected from the group consisting of water, ethanol, ethyl ether, acetone, tetrahydrofuran, benzene, toluene, xylene, dimethyl formamide and N-methyl pyrrolidone.
In the present invention, the porous silicon substrate is prepared at a temperature of 600 to 900° C. If the temperature is below 600° C., the reduction reaction of the mesoporous silica is not sufficient. If the temperature is higher than 900° C., the grain size of the obtained product is too large. The temperature for coating carbon is in a range of 600 to 1100° C. If the temperature is below 600° C., carbonization is incomplete or the conductivity of carbon is not high. If the temperature is higher than 1100° C., impurities such as SiC are formed.
For the preparation method of the mesoporous silica used in the above method, please refer to for example Science, 1998, volume 279, Issue 5350, pages 548 to 552. 1 to 8 parts of ethylene oxide/propylene oxide block copolymer are dissolved in a solution of 10 to 50 parts of water, 0 to 9 parts of 1-butanol and 3 to 6 parts of 2 mol/L of hydrochloric acid. After stirring, 6 to 12 parts of tetraethyl orthosilicate is added to the mixture, and stirred at 10 to 50° C. for 12 to 36 hours. The mixture is then transferred into a hydrothermal reaction kettle, where the temperature is kept at 80° C. to 120° C. for 12 to 36 hours. After cooling, by centrifugation at 3,000 to 10,000 r/min, vacuum drying at 80° C. to 120° C., and calcination at 500° C. to 800° C. for 1 to 6 hours, mesoporous silica is obtained.
The silicon-carbon composite anode material for lithium ion batteries of the present invention consists of a porous silicon substrate and a carbon coating layer. The porous silicon substrate has a uniformly distributed porous structure, which not only effectively alleviates the volume effect of silicon during the lithium deintercalation process, but is also favorable for the penetration of the electrolyte and the transmission of lithium ions, the diffusion distance of lithium ions in silicon is reduced, and high current charge-discharge of the silicon anode is realized. The carbon coating layer also serves to enhance conductivity and maintain the structural stability of the material, so that the silicon-carbon composite anode material for lithium ion batteries of the present invention has the advantages of a high reversible capacity, good cycle performance and excellent rate performance. In the preparation method of the silicon-carbon composite anode material for lithium ion batteries of the present invention, firstly, the mesoporous silica is reduced with magnesium, a porous silicon substrate is obtained after pickling, and then a uniform carbon coating layer is coated on the porous silicon substrate surface so as to improve conductivity, with no use of noble metals. This method is simple, low cost, and is suitable for large-scale industrial production.
Using a lithium plate as the counter electrode, the silicon-carbon composite anode material for lithium ion batteries of the present invention can be assembled into a lithium ion battery. The lithium ion battery has electrolyte consisting of a lithium salt and a solvent. The lithium salt can be selected from the group consisting of inorganic salts, such as lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ) or lithium perchlorate (LiClO 4 ); and organic salts, such as lithium bis(oxalate)borate (LiBOB), lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). The solvent contains at least one compound from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC) and diethyl carbonate (DEC). The concentration of the lithium salt in the electrolyte is less than 2 mol/L. Constant current charge-discharge tests are carried out at the rate of 0.2 C. The results show that the initial coulombic efficiency is 72%. The reversible capacity after 40 cycles remains above 1500 mAh/g, the capacity retention rate is up to 90%. Tests are carried out at rates of 0.2 C, 1 C, 4 C and 8 C, the silicon-carbon composite anode material for lithium ion batteries of the present invention shows reversible capacity of 1556 mAh/g, 1290 mAh/g, 877 mAh/g and 598 mAh/g respectively, wherein the current density at 0.2 C is 300 mA/g. Even if the charge-discharge tests are carried out at 15 C, a reversible capacity of 474 mAh/g is exhibited.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the SEM image (a) and the TEM image (b) of the porous silicon substrate obtained in Example 1.
FIG. 2 shows the pore size distribution curve of the porous silicon substrate obtained in Example 1.
FIG. 3 shows the TEM image of the silicon-carbon composite anode material for lithium ion batteries obtained in Example 1.
FIG. 4 shows the charge-discharge curve at the first, the second and the tenth cycle of the silicon-carbon composite anode material for lithium ion batteries obtained in Example 1.
FIG. 5 shows the capacity versus cycle number curve of the first 40 cycles of the lithium ion battery assembled from the silicon-carbon composite anode material for lithium ion batteries obtained in Example 1.
FIG. 6 shows the capacity versus cycle number curve at various rates of the lithium ion battery assembled from the silicon-carbon composite anode material for lithium ion batteries obtained in Example 1.
FIG. 7 shows the TEM image of the silicon-carbon composite anode material for lithium ion batteries obtained in Example 2.
FIG. 8 shows the SEM image of the porous silicon substrate obtained in Example 3.
FIG. 9 shows the capacity versus cycle number curve of the first 40 cycles of the lithium ion battery assembled from the silicon-carbon composite material obtained in Comparative Example 1 which does not have a porous structure.
FIG. 10 shows the capacity versus cycle number curve of the first 40 cycles of the lithium ion battery assembled from the porous silicon substrate obtained in Comparative Example 2 which does not have a carbon coating layer.
DETAILED DESCRIPTION OF THE INVENTION
The following examples further illustrate the present invention, but the present invention is not limited to the following Examples.
Assembly of the lithium ion battery and the test method are described as follows.
The silicon-carbon composite anode material for lithium ion batteries of the present invention, 20 wt % of the binder (a N-methylpyrrolidone solution of polyvinylidene fluoride with a concentration of 2 wt %, or a styrene-butadiene rubber-sodium carboxymethyl cellulose emulsion) and 20 wt % of a conductive agent (SuperP conductive carbon black) were mixed and stirred uniformly, then the material was coated on a copper foil which is then placed in a drying oven at 60° C. to 80° C. The copper foil was punched into an electrode with a 12-16 mm diameter puncher. The electrode is placed in a vacuum oven and dried at 0° C. to 120° C. for 8 to 12 hours, then transferred into an argon-filled glove box. A lithium plate is used as a counter electrode, ENTEK PE porous membrane is used as a separator, 1 mol/L of lithium hexafluorophosphate in a mixed solution of ethylene carbonate with dimethyl carbonate (volume ratio 1:1) is used as the electrolyte. Thus a button battery CR2016 is assembled. Constant current charge-discharge performance test is carried out on a LAND battery test system (Wuhan Jinnuo Electronics Co., Ltd.). The charge-discharge cut-off voltage with respect to Li/Li + is 0.01 to 1.2 V, the charge-discharge rate is 0.05 C to15 C, wherein the current density at the rate of 0.2 C is 300 mA/g.
EXAMPLE 1
Preparation of mesoporous silica: 4.0 g of ethylene oxide/propylene oxide block copolymer (tradename: Pluronic P123) was dissolved in a mixed solution of 30.0 g of water and 120.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 8.4 g of tetraethyl orthosilicate (TEOS) was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 4000 r/min, dried at 95° C., and then calcined at 550° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.3 g of mesoporous silica and 0.3 g of magnesium powder were placed in a high temperature furnace. In a gas mixture of argon and hydrogen (the content of hydrogen was 5% by volume), the temperature was raised to 650° C., and temperature was kept for 7 hours before it was allowed to cool. Then the materials were put into 25 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 4000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) The porous silicon substrate was placed in a high temperature furnace, where the temperature was raised to 900° C. in an atmosphere of argon. Then acetylene was carried into the furnace by argon (the volume ratio of argon and acetylene was 5:1 and the total flow rate was 300 ml/min), the temperature was kept for 4 hours. After the disassociation of acetylene, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The morphology and structure of the porous silicon substrate was shown in FIG. 1 . The particles were approximate cylindrical with a length of approximately 600 nm and a diameter of approximately 400 nm, and the substrate shows a porous structure. The pore size distribution curve shown in FIG. 2 indicates that the pore size was about 40 nm, the pore volume was 0.56 cm 3 /g, the specific surface area was 78.5 m 2 /g. FIG. 3 shows a TEM image of the interface of the porous silicon substrate with the carbon coating layer. Silicon crystal plane (111) can be seen from FIG. 3 , and the plane spacing was 0.31 nm; the carbon coating layer consists of amorphous carbon, and its thickness was approximately 7 nm. The carbon coating layer accounted for 40.0 wt %. It can be seen from the electron diffraction image in FIG. 3 that the silicon was of a polycrystalline structure. The polycrystalline diffraction ring having the smallest diameter in the image corresponds to (111) crystal plane of the silicon.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. FIG. 4 shows the charge-discharge curve of the first three cycles. FIG. 5 shows the capacity versus cycle number of the first 40 cycles. The initial charge-discharge coulombic efficiency was 72.0%. The reversible capacity after 40 cycles at the rate of 0.2 C was 1509 mAh/g, the capacity retention rate was 90.1%. Tests were carried out at rates of 0.05 C, 0.2 C, 0.5 C, 1 C, 4 C, 8 C and 15 C, the silicon-carbon composite anode material for lithium ion batteries of the present invention showed reversible capacity of 1583 mAh/g, 1556 mAh/g, 1370 mAh/g, 1290 mAh/g, 877 mAh/g, 598 mAh/g and 474 mAh/g, as can be seen in FIG. 6 . The electrochemical properties of this material were better than the traditional silicon-carbon composite material.
EXAMPLE 2
Preparation of mesoporous silica: 3.0 g of Pluronic P123 was dissolved in a mixed solution of 22.5 g of water, 3.0 g of 1-butanol and 90.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 6.3 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 4000 r/min, dried at 100° C., and then calcined at 600° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.4 g of mesoporous silica and 0.4 g of magnesium powder were placed in a high temperature furnace. In an atmosphere of argon, the temperature was raised to 700° C., and temperature was kept for 6 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 4000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) The porous silicon substrate was placed in a high temperature furnace, where the temperature was raised to 800° C. in an atmosphere of nitrogen. Then toluene was carried into the furnace by nitrogen (the flow rate of nitrogen was 800 ml/min), the temperature was kept for 2 hours. After the disassociation of toluene, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 2.4 μm, the average pore size was 35 nm, the pore volume was 0.61 cm 3 /g, the specific surface area was 73.3 m 2 /g. FIG. 7 shows a TEM image of the silicon-carbon composite anode material for lithium ion batteries. It can be seen from FIG. 7( a ) that the material has a porous structure. FIG. 7( b ) shows the interface of the porous silicon substrate with the carbon coating layer. Crystal plane (111) can be seen from FIG. 7( b ) , and the plane spacing was 0.31 nm. The carbon coating layer consists of amorphous carbon and has a thickness of 5 nm. The carbon coating layer accounted for 25.6 wt %.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 75.2%. The reversible capacity after 40 cycles was 1325 mAh/g, and the capacity retention rate was 73.7%.
EXAMPLE 3
Preparation of mesoporous silica: 4.0 g of Pluronic P123 was dissolved in a mixed solution of 30.0 g of water, 4.0 g of 1-butanol and 120.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 8.4 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 4000 r/min, dried at 100° C., and then calcined at 600° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.4 g of mesoporous silica and 0.4 g of magnesium powder were placed in a high temperature furnace. In a gas mixture of argon and hydrogen (the content of hydrogen was 5% by volume), the temperature was raised to 750° C., and temperature was kept for 7 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 4000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) The porous silicon substrate was placed in a high temperature furnace, where the temperature was raised to 900° C. in an atmosphere of argon. Then acetylene was carried into the furnace by argon (the volume ratio of argon and acetylene was 4:1 and the total flow rate was 250 ml/min), the temperature was kept for 3 hours. After the disassociation of acetylene, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 2.5 μm, the average pore size was 32 nm, the pore volume was 0.64 cm 3 /g, the specific surface area was 73.0 m 2 /g. FIG. 8 shows the morphology. The silicon-carbon composite anode material for lithium ion batteries comprised 34.6 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 6 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 72.2%. The reversible capacity after 40 cycles was 1570 mAh/g, and the capacity retention rate was 84.8%.
EXAMPLE 4
Preparation of mesoporous silica: 2.0 g of Pluronic P123 was dissolved in a mixed solution of 15 g of water and 60.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 4.2 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 5000 r/min, dried at 90° C., and then calcined at 650° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.35 g of mesoporous silica and 0.35 g of magnesium powder were placed in a high temperature furnace. In an atmosphere of argon, the temperature was raised to 700° C., and temperature was kept for 6 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 5000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) The porous silicon substrate was placed in a high temperature furnace, where the temperature was raised to 770° C. in an atmosphere of nitrogen. Then toluene was carried into the furnace by nitrogen (the flow rate of nitrogen was 1000 ml/min), the temperature was kept for 1 hour. After the disassociation of toluene, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 700 nm, the average pore size was 23 nm, the pore volume was 0.42 cm 3 /g, the specific surface area was 78.1 m 2 /g. The silicon-carbon composite anode material for lithium ion batteries comprised 18.3 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 4 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 76.5%. The reversible capacity after 40 cycles was 1825 mAh/g, and the capacity retention rate was 83.6%.
EXAMPLE 5
Preparation of mesoporous silica: 3.5 g of Pluronic P123 was dissolved in a mixed solution of 26.3 g of water and 105.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 7.4 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 5000 r/min, dried at 80° C., and then calcined at 600° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.3 g of mesoporous silica and 0.3 g of magnesium powder were placed in a high temperature furnace. In a gas mixture of argon and hydrogen (the content of hydrogen was 10% by volume), the temperature was raised to 700° C., and temperature was kept for 7 hours before it was allowed to cool. Then the materials were put into 25 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 5000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) 0.2 g of the porous silicon substrate and 0.7 g of polyvinyl chloride were dispersed in 15 ml of tetrahydrofuran. The mixture were dispersed homogeneously by an ultrasonic treatment and stirring. Then tetrahydrofuran was evaporated, the material was transferred into a high temperature furnace where the temperature was raised to 900° C. in an atmosphere of argon, the temperature was kept for 2 hours. After the disassociation of polyvinyl chloride, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 650 nm, the average pore size was 24 nm, the pore volume was 0.43 cm 3 /g, the specific surface area was 77.8 m 2 /g. The silicon-carbon composite anode material for lithium ion batteries comprised 31.4 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 6 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 74.1%. The initial lithium intercalation capacity was 1855 mAh/g, the initial lithium deintercalation capacity was 1374 mAh/g.
EXAMPLE 6
Preparation of mesoporous silica: 2.0 g of Pluronic P123 was dissolved in a mixed solution of 15.0 g of water, 2.0 g of 1-butanol and 60.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 4.2 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 6000 r/min, dried at 100° C., and then calcined at 550° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.35 g of mesoporous silica and 0.35 g of magnesium powder were placed in a high temperature furnace. In an atmosphere of argon, the temperature was raised to 650° C., and temperature was kept for 7 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 6000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) 0.2 g of the porous silicon substrate and 0.4 g of polyacrylonitrile were dispersed in 10 ml of dimethyl formamide. The mixture were dispersed homogeneously by an ultrasonic treatment and stirring. Then dimethyl formamide was evaporated, the material was transferred into a high temperature furnace where the temperature was raised to 900° C. in an atmosphere of nitrogen, the temperature was kept for 2 hours. After the disassociation of polyacrylonitrile, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 2.5 μm, the average pore size was 34 nm, the pore volume was 0.66 cm 3 /g, the specific surface area was 72.8 m 2 /g. The silicon-carbon composite anode material for lithium ion batteries comprised 20.9 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 4 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 64.0%. The initial lithium intercalation capacity was 1242 mAh/g, the initial lithium deintercalation capacity was 795 mAh/g.
EXAMPLE 7
Preparation of mesoporous silica: 3.0 g of Pluronic P123 was dissolved in a mixed solution of 22.5 g of water, 3.0 g of 1-butanol and 135.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 9.5 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 5000 r/min, dried at 80° C., and then calcined at 650° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.45 g of mesoporous silica and 0.45 g of magnesium powder were placed in a high temperature furnace. In an atmosphere of argon, the temperature was raised to 750° C., and temperature was kept for 6 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 5000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) 0.3 g of the porous silicon substrate and 0.95 g of polyvinyl chloride were dispersed in 10 ml of tetrahydrofuran. The mixture were dispersed homogeneously by an ultrasonic treatment and stirring. Then tetrahydrofuran was evaporated, the material was transferred into a high temperature furnace where the temperature was raised to 900° C. in an atmosphere of argon, the temperature was kept for 4 hours. After the disassociation of polyvinyl chloride, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 2.6 μm, the average pore size was 33 nm, the pore volume was 0.65 cm 3 /g, the specific surface area was 72.9 m 2 /g. The silicon-carbon composite anode material for lithium ion batteries comprised 29.3 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 6 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 67.2%. The initial lithium intercalation capacity was 1291 mAh/g, the initial lithium deintercalation capacity was 867 mAh/g.
EXAMPLE 8
Preparation of mesoporous silica: 4.0 g of Pluronic P123 was dissolved in a mixed solution of 30.0 g of water and 120.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 8.4 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 5000 r/min, dried at 80° C., and then calcined at 550° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.35 g of mesoporous silica and 0.4 g of magnesium powder were placed in a high temperature furnace. In a gas mixture of argon and hydrogen (the content of hydrogen is 10% by volume), the temperature was raised to 700° C., and temperature was kept for 7 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 5000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained;
(2) 0.25 g of the porous silicon substrate and 0.5 g of polyacrylonitrile were dispersed in 15 ml of dimethyl formamide. The mixture were dispersed homogeneously by an ultrasonic treatment and stirring. Then dimethyl formamide was evaporated, the material was transferred into a high temperature furnace where the temperature was raised to 900° C. in an atmosphere of nitrogen, the temperature was kept for 4 hours. After the disassociation of polyacrylonitrile, a carbon coating layer was formed on the surface of the porous silicon substrate, thus a silicon-carbon composite anode material for lithium ion batteries was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 600 nm, the average pore size was 24 nm, the pore volume was 0.44 cm 3 /g, the specific surface area was 77.7 m 2 /g. The silicon-carbon composite anode material for lithium ion batteries comprised 21.3 wt % of the carbon coating layer which consists of amorphous carbon and has a thickness of 4 nm.
The silicon-carbon composite anode material for lithium ion batteries thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. The initial charge-discharge coulombic efficiency was 72.0%. The initial lithium intercalation capacity was 1263 mAh/g, the initial lithium deintercalation capacity was 910 mAh/g.
COMPARATIVE EXAMPLE 1
0.15 g of nano silicon powder (particle size: 50 to 150 nm) and 0.45 g of polyvinyl chloride were dispersed in 10 ml of tetrahydrofuran. The mixture were dispersed homogeneously by an ultrasonic treatment and stirring. Then tetrahydrofuran was evaporated, the material was transferred into a high temperature furnace where the temperature was raised to 900° C. in a gas mixture of nitrogen and hydrogen (the content of hydrogen is 5% by volume), the temperature was kept for 2 hours. After the disassociation of polyvinyl chloride and cooling, a silicon-carbon composite material free of pores was obtained. The carbon coating layer accounted for 28.8 wt %, it consisted of amorphous carbon and had a thickness of 6 nm.
The silicon-carbon composite material thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. FIG. 9 shows the capacity versus cycle number curve of the first 40 cycles. The initial charge-discharge coulombic efficiency was 78.0%. The initial reversible capacity was 1194 mAh/g, the reversible capacity after 40 cycles was 186 mAh/g, thus the capacity retention rate was only 15.6%.
COMPARATIVE EXAMPLE 2
Preparation of mesoporous silica: 2.0 g of Pluronic P123 was dissolved in a mixed solution of 15.0 g of water, 2.0 g of 1-butanol and 60.0 g of hydrochloric acid (2 mol/L), after being stirred homogeneously, 4.2 g of TEOS was added therein. The mixture was then stirred at 35° C. for 24 hours and transferred into a hydrothermal reaction kettle where the temperature was kept at 100° C. for 24 hour. After being cooled, the mixture was centrifugalized at 5000 r/min, dried at 90° C., and then calcined at 650° C. in an air atmosphere for 2 hours. Thus, mesoporous silica was obtained.
(1) 0.35 g of mesoporous silica and 0.35 g of magnesium powder were placed in a high temperature furnace. In a gas mixture of argon and hydrogen (the content of hydrogen is 5% by volume), the temperature was raised to 700° C., and temperature was kept for 6 hours before it was allowed to cool. Then the materials were put into 30 ml of hydrochloric acid (2 mol/L) and stirred for 12 hours. After 4 times of centrifugation at 5000 r/min, and vacuum drying at 80° C. for 12 hours, a porous silicon substrate was obtained.
The porous silicon substrate was of a polycrystalline structure, the average particle size was 2.5 μm, the average pore size was 34 nm, the pore volume was 0.66 cm 3 /g, the specific surface area was 72.8 m 2 /g. No carbon coating layer was formed.
The silicon-carbon composite material thus prepared was assembled into a lithium ion battery, on which charge-discharge tests were carried out. FIG. 10 shows the capacity versus cycle number curve of the first 40 cycles. The initial charge-discharge coulombic efficiency was 81.1%. The initial reversible capacity was 2837 mAh/g, the reversible capacity after 40 cycles was 1554 mAh/g, thus the capacity retention rate was only 54.8%.
Compared with the silicon-carbon composite material of Comparative Example 1 which does not have a porous structure, it can be seen that the silicon-carbon composite material for lithium ion batteries of the present invention having a porous structure and a carbon coating layer has a better cycle performance. This results from the uniform distribution of the porous structure, which can effectively alleviate the volume effect during the lithium intercalation and deintercalation process and improve the stability of the electrode structure.
Compared with the porous silicon material of Comparative Example 2 which does not have a carbon coating layer, it can be seen that the silicon-carbon composite material for lithium ion batteries of the present invention having a porous structure and a carbon coating layer has a better cycle performance This results from the carbon coating layer which improves conductivity and maintains an electrode conductive network.
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Disclosed in the invention are a silicon-carbon composite anode material for lithium ion batteries and a preparation method thereof The material consists of a porous silicon substrate and a carbon coating layer. The preparation method of the material comprises preparing a porous silicon substrate and a carbon coating layer. The silicon-carbon composite anode material for lithium ion batteries has the advantages of high reversible capacity, good cycle performance and good rate performance. The material respectively shows reversible capacities of 1,556 mAh, 1,290 mAh, 877 mAh and 474 mAh/g at 0.2 C, 1 C, 4 C and 15 C rates; the specific capacity remains above 1,500 mAh after 40 cycles at the rate of 0.2 C and the reversible capacity retention rate is up to 90 percent.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Application having Ser. No. 60/914,544 filed on Apr. 27, 2007, which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates generally to organizing digital files and in particular, to organizing digital photos using optical parameters stored in camera metadata.
Much of the research in content based image classification and retrieval has focused on using two types of information sources: the pixel layer of an image and text present along with an image. It is known in the art of image retrieval systems to use various measures on the image features such as, color, texture, or shape. Other methods search images for local features such as edges, salient points, or objects. Algorithms have also been proposed which find scale and rotation invariant distinctive feature points in an image. These systems help in image matching and query by example. But image search using an example or low level features might be difficult and non-intuitive to some people. Rather image search using keywords has become more popular nowadays.
The prior art has used mapping on low level image features to semantically classify coherent image classes. It is known to use an algorithm on color and texture features to classify indoor outdoor images. One publication, “Content Based Hierarchical Classification of Vacation Images”. In Proc. IEEE Multimedia Computing and Systems , June 1999 (518-523), by Vailaya et al. discloses uses of a hierarchical structure to classify images into indoor-outdoor classes; then outdoor images into city and landscape. Other applications, such as image search engines rely on text, tags, or annotations to retrieve images.
Research using the annotations/tags or text accompanying an image in the prior art has been used to derive the human meta information from text accompanying the image. As disclosed in “Integration of visual and text-based approaches for the content labeling and classification of photographs” by Paek et al., they then combine the image features and text labels to classify photographs.
In some of the prior art, human agents are used to tag some images using predefined tags. An algorithm then predicts some tags on untagged images. This approach suffers from the fact that it is non trivial to define particular image classes especially for large heterogeneous image databases. Some may find that tagging an image to a particular class depends on the user's perception on a particular image.
Other prior art approaches have used the Optical Meta layer to classify and annotate images. Some use this layer to help improve classification using the pixel layer such as by using pixel values and optical metadata for sunset scene and indoor outdoor classification. Such approaches may choose the most significant cue using K-L divergence analysis. Others use a color, texture and camera metadata in a hierarchical way to classify indoor and outdoor images. But indoor-outdoor are considered by some very broad classes to actually help in any annotation or retrieval. Also these approaches lack the use of any strong reference to physics of vision (of why the images were being classified using the chosen cues). Further, the training sets used in the research have been artificially created for a specific purpose only.
As can be seen, there is a need for an improved method of classifying digital images for organization and retrieval that exploits inherent optical parameters for intuitive grouping by extracting similar optical features. Furthermore, it can be seen that a need exists for a method that automatically annotates digital images based on similar optical features.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a method for classifying digital images comprises clustering optical parameters of the digital images into a set of meaningful clusters, associating the set of meaningful clusters to a set of associated classes used by a user, and classifying the digital images according to the set of associated classes.
In another aspect of the present invention, a method for organizing digital images comprises deriving optical parameters from the digital images, accessing a set of subject classes commonly used by a user and assembled into predefined parameters, determining what the user was trying to capture in the digital image by associating the derived optical parameters with the set of digital image subject classes, and organizing the digital images into classifications according to the associations determined by the derived optical parameters.
In yet another aspect of the present invention, a method for using optical metadata of a digital image to classify the digital image comprises analyzing the optical metadata to find clusters of digital images having similar optical concepts, comparing the clusters with human induced classes and corresponding the human induced classes with a classification for the digital image.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a layered digital image structure according to the present invention;
FIG. 2 is an illustration of successive F-numbers and related aperture sizes in a camera;
FIG. 3 is an illustration depicting focal length in relation to field of view;
FIG. 4 is a series of graphs showing the distributions of: a: Exposure Time, b: Log Exposure Time, c: Focal Length d: F-Number, e: Flash, f: Metering Mode;
FIG. 5 is a graph showing ISO speed rating and exposure time;
FIG. 6 is a series of graphs showing the distribution of Log light metric for images without flash (a) and with flash (b);
FIG. 7 is a series of graphs showing the Gaussian Mixture Models for photos without (a) and with flash (b);
FIG. 8 is a series of graphs showing the BIC criterion values;
FIG. 9 is a series of graphs showing the Gaussian mixtures on aperture diameter and focal length;
FIG. 10 shows two scatter plots of aperture diameter vs. focal length;
FIG. 11 shows two scatter plots of aperture diameter vs. focal length;
FIG. 12 shows a map of human classes to optical clusters;
FIG. 13 shows a series of models showing a Bayes Net modeling of images;
FIG. 14 is a set of annotated images with manual and predicted tags;
FIG. 15 is a set of annotated images with manual and predicted tags;
FIG. 16 shows a series of graphs describing the distribution of human induced classes over optical clusters;
FIG. 17 schematically represents a series of steps involved in a method for classifying digital photo images, according to another embodiment of the invention; and
FIG. 18 is a table depicting predicted annotations for untagged images.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
The traditional camera records information (coming through the incident light) on films using chemical symbols. The digital camera has CCD/CMOS image sensors which capture visual signals and store them in the electromagnetic memory. But apart from visual signal, the digital camera stores other context information too. Hence, referring to FIG. 1 , an exemplary multilayered structure of a digital photograph 101 may be proposed. The layers are i. Pixel/Spectral layer 110 and ii. Meta Layer 120 . The pixel layer 110 may contain the information recorded by the CCD as pixel values. The Meta Data Layer may have the following sub layers: a. Optical Meta Layer 130 ; b. Temporal Meta Layer 140 . c. Spatial Meta Layer 150 ; d. Human Induced Meta Layer 160 ; and e. Derived Meta Layer 170 . The optical meta layer 130 may contain the metadata related to the optics of the camera; e.g., the focal length, aperture, exposure time etc. These metadata contain important cues about the context in which the image was shot (like the lighting condition, depth of field and distance of subjects in the image). The temporal meta layer 140 may contain the time stamp of the instant in which the photo was shot. The time stamp of a single image in a standalone environment may not be informative enough. But in a collection of images (e.g., photo albums) the time difference can shed valuable light on the content of the images. The spatial meta layer 150 may contain the spatial coordinates of the places where pictures were shot. These coordinates are generated by the GPS systems attached to the camera. Today some off the shelf cameras do not have GPS support. This contains the tags/comments/ratings posted by people. Community tagging (in online photo albums) also helps to generate data for this layer. The Derived Meta Layer 170 metadata can be inferred from other information by learning algorithms, e.g., automatic annotation. The taxonomy defined above helps us to define the sources of information present in a digital camera image. Presently, the spectral, optical and temporal layers are present in almost all digital photographs, while the spatial, human induced and Derived Meta layers may or may not be present.
Most off the shelf digital cameras (both point and shoot and SLR (single lens reflex)) have built-in electronics to determine the outside illumination, subject distances etc. Cameras in auto mode or different preset modes (Portrait/Night etc) use these electronics to tune the camera optics and store the information in the optical meta layer 130 . The present invention uses the information stored in the optical meta layer in inferring the content of an image. The present invention uses unsupervised learning algorithms to find clusters of images having similar ‘optical concepts’. The clusters are then compared with human induced semantic classes to show how they correspond.
The present invention may have, as representative examples, many advantages. For example, the optical meta information is used to infer the semantic content of an image. A probabilistic model is used to express the inference. Since the information in the optical meta layer is stored as real valued numbers (obtained from sensors), it can be retrieved and processed fast. Thus an algorithm can be used in the top level of any hierarchical image classification/automatic annotation system. Additionally, rather than using optical meta data as independent tags, novel metrics may be defined dependent on multiple optical meta tags as explained by the physics of vision and camera. Unlike related image classification research, a small set of classes may not be solely considered (like indoor-outdoor or city-landscape). A survey was used to determine the most common classes amateurs like to shoot using the off the shelf digital cameras. These human-induced classes were used as semantic image concepts. Their correspondence may be shown with the clusters defined by Optical Meta layer 130 . The image data set derived from the survey consists of personal photos from at least thirty different amateur users. They were shot in a completely unconstrained environment, through a time span of six years and on four different continents. Hence the data set may be considered highly heterogeneous.
Background Study on Camera Parameters
The Exchangeable Image File (EXIF) Standard specifies the camera parameters to be recorded for a photo shoot. The actual parameters recorded depend on the particular camera manufacturer. But there are certain fundamental parameters which are recorded by all popular camera models. These are exposure time, focal length, f-number, flash, metering mode and ISO. An examination of seven different camera models (Canon, Casio, Sony, Nikon, Fuji, Kodak, and Konica) showed some commonalties. All of them have these parameters in the EXIF header. In the image database of 30,000 photos, over 90% of the images have these attributes. Subject distance may be one an important optical parameter which has been used to infer the image content. However it showed up only present in less than ten percent of the images. These parameters help capture the information related to the intent of the photographer. This intent can be inferred using parameter values and sophisticated analysis and thus, may be very effective in classification and annotation of images. In the following, descriptions of the parameters used for coding the intent are discussed and in subsequent sections, approaches to decode the intent from the parameters are developed.
Exposure Time/Shutter Speed
The time interval for which the shutter of a camera is kept open to allow the external light into the camera is known as exposure time. It is measured in seconds. Exposure time is directly proportional to the amount of light incident on the image plane. It also controls the motion blur in an image.
Aperture/F-Number
Referring to FIG. 2 , aperture relates to the size of the opening through which light enters a camera. This size is controlled by a diaphragm over the opening which can close in or open up. The aperture size affects the amount of light on the image plane and the depth of field. Rather than using absolute aperture diameters, photographers use relative aperture, expressed as f-numbers or f-stops. Some point and shoot cameras have some discrete values of the f-stops. Mathematically,
F -Number=Focal Length/Diameter of the aperture
Generally, point and shoot cameras have some discrete values of the F-stops. Each successive f-stop halves or doubles the amount of light entering the camera.
Focal Length
With reference to FIG. 3 , a focal plane is the plane where subjects at infinity are focused (by a lens). The distance between the optical center of the lens to the focal plane is known as the focal length. The field of view of the camera is determined by the focal length and the size of the camera sensor. Short focal length lens have wide field of views (wide angle) and long focal length lens have narrow field of view (telephoto). Generally, the point and shoot digital cameras have short focal lengths and small image sensors. Hence, they generally produce wide angle images. FIG. 3 depicts a general relationship between the focal length of camera lenses and their effects on field of view.
Flash
Flash is the artificial light source within a camera. Other than using the flash for a shot in dark regions, it can also be used as ‘fill in flash’ in bright outdoor shots. This will help to make the shadowy areas less dark and decrease contrast in lighting. Flash status (fired/not-fired) may be stored in the metadata.
Film Speed/ISO
ISO speed ratings indicate the level of sensitivity of the image sensor (CCD) towards light. In traditional film cameras, ISO sensitivity is associated with a film stock. Lower ISO films are relatively finer in grain but require more light (e.g., outdoor day shots). High ISO films (more sensitive) are required for low light or action photography; but can produce grainy images. In digital cameras ISO speed can be changed depending on circumstances without any media change. Hence the ISO speed rating of a digital camera may not be much related to the ISO rating of a film camera.
Distribution of Camera Parameters
A 30 thousand digital photograph database was created from images taken from at least thirty different users. Images were also gathered from the MIT Label Me project and the SIMPLIcity project. Most of the images were shot using point and shoot cameras and in completely unconstrained environment. Spatially, the images are from at least four different continents (North and South Americas, Europe, Asia), and temporally they span a period of six years. One goal of using such a database is to find the distribution of optical meta data in amateur photographs for help in classification and retrieval of digital images. Due to the heterogeneity of the dataset it can be inferred to model an online community photo album.
FIGS. 4( a )- 4 ( f ) show the distribution of the various parameters in the image database. Referring to FIG. 4( a ) the distribution of exposure time (in sec) may be considered highly skewed. Less than one percent of the images have an exposure time of more than 0.5 second. The log-exposure time distribution is shown in FIG. 4( b ). Distribution of focal length in millimeters is shown in FIG. 4( c ). Since most of the images were shot by regular point and shoot cameras (which typically are wide angle with smaller relative aperture), the majority of images have a focal length in the range 0-100 mm. About 1-2% of the images have a focal length more than 100 mm. The distribution of F-Numbers is also skewed towards the lower end of the spectrum as seen in FIG. 4( d ). Referring to FIG. 4( e ), flash is a hex byte and its distribution shows various states of the flash, detection of reflected light and red eye detection mechanism. Most of the images have a metering mode five (multi zone). A small percentage has values 2 (spot) and 3 (center weighted average). Amateurs typically shoot photos in auto mode. The camera makes decisions on the optical parameters based on the feedback from other sensors (like light meters). One aspect of the present invention may invert this process and infer image content based on the optical parameters.
Visual Cues Extracted from Optical Parameters Amount of Incident Light
Some in the art may interpret the distributions of the optical parameters to indicate that none of the parameters have sufficient discriminative power for meaningful classification when considered independently. However, the joint distribution of the parameters may be examined for important visual cues. One important cue which is hidden in the Optical Meta layer is the amount of ambient light when a photo was shot. Exposure time and aperture size may provide a strong hint about the amount of light. The camera's response to the incident light depends on the ISO speed ratings. In traditional film cameras, a particular film stock had a predefined ISO speed rating; hence other optical parameters may be changed to take different shots with a particular film. But in digital cameras, the ISO can be changed independently from other parameters.
Referring to FIG. 5 , a chart shows ISO speed rating and exposure time are uncorrelated. To estimate the ambient lighting condition a metric may be defined based on the premise that the amount of light entering a camera is directly proportional to:
the exposure time (ET),
Area of the aperture opening (AP-Area),
ISO speed rating of the sensor (ISO).
Thus this measure can be expressed as:
Light Metric=ET×AP-Area×ISO,
where, the proportionality may be considered constant as 1 and the log of this value is called it the log Light Metric. Note that, log Light Metric will have a small value when the ambient light is high (the camera will have a low exposure time, small aperture and low ISO). Similarly it will have a large value if the outdoor light is small. Also the camera itself can create some artificial light using the flash. Hence one may study the distribution of this light metric separately on photographs with flash and without flash as shown in FIGS. 6( a ) and 6 ( b ).
Depth of Field (DOF)
The lens generally focuses at a particular distance (a plane) in front of the camera. All objects on the focusing plane are sharp; and theoretically objects not on the focusing plane are blurred. However, due to the constraints of the human eye, some areas in front and behind the focused subject appear acceptably sharp. This area is known as depth of field. The depth of field depends on the aperture size (diameter), the subject distance, the target size and the focal length. Decreasing the aperture diameter increases the depth of field and vice versa. Some believe that, if the target size on the image plane remains constant then DOF is independent of focal length. But to keep the target size constant over a range of focal lengths, the subject distance needs to change. Hence the photographer has to move a lot. But in normal daily shots, amateurs hardly care about maintaining a fixed target size on the image plane. Hence a longer focal length usually indicates a shallow depth of field as it flattens perspective (especially in outdoor shots). The aperture diameter can be decreased to increase the depth of field; but decreasing aperture also limits the amount of light entering the camera. To make sure a considerable amount of light enters the image plane after diffraction, the aperture opening should not be made arbitrarily small. A small target size (e.g., flowers, insects, decorative objects) will lead to lower DOF as the goal of such images is to separate the target out from the background.
Unsupervised Clustering
Unlike the prior art, the present invention derives optical parameters from digital images to model the human concept of image content. The survey indicates that classes of images in personal photo albums may be highly diverse and overlapping. It may be very difficult to come up with some predefined set of class names which are mutually exclusive and exhaustive. Further associating an image with a particular class depends on the user's perception. For example, the shot of a baby may be assigned class names such as: baby, portrait, person; the shot of people in restaurants can be assigned class names: restaurants, parties, people at dinner, etc. Thus a single image may be assigned to multiple classes by the same or different person. Also the knowledge of a particular incident may generate multiple class names like birthday party, marriage anniversary or family get-together. Hence without tagging images into a set of class names, unsupervised learning techniques may be used to find clusters of images with similar ‘optical concepts’. To see how these optical concepts map to human concepts of subject image classes commonly used, surveys were performed about types of images amateurs generally shoot. Then an examination of how these human defined classes correlated with the unsupervised clusters was performed.
The Clustering Model
A hierarchical clustering method was chosen to find similar ‘optical concepts’ in the image database. At each level, the most important exemplary visual cue was chosen. Then, the distribution of the visual cue was modeled as a mixture of Gaussians. This has two advantages: Due to the hierarchical structure, one can infer which visual cue is affecting which clusters, and give a hypothesis on the content of the cluster. Without prior knowledge of the distribution of the optical parameters, a Bayesian Model Selection may be used to find the optimum model and Expectation Maximization (EM) algorithm to fit the model. When EM is used to find the maximum likelihood, the Bayesian model selection can be approximated by the Bayesian Information Criterion (BIC).
BIC=LL−NumParam/2×log( N ), where
i. LL=Log Likelihood of the data for the Model
ii. =Log [Prob(data|Model)], and NumParam=number of independent parameters in the model. For a Gaussian mixture model, the parameters are the means and covariance. Hence, NumParam=K×(1+Dim*Dim), where K is the number of components in the mixture, N is the number of data points, Dim is the dimensionality of the variables.
Hierarchical Clustering
Light is one important visual cue in any photo. The light-content in the images may be modeled in the first level of the hierarchy. Flash is an external light source which influences the ambient light during a photo shoot. Thus, in one exemplary method of the present invention, photos may be separated with and without flash in the first level of hierarchy. In the second level, images may be clustered based on the ambient lighting condition. The LogLightMetric may be used to estimate the ambient light. Then, the hierarchical clustering algorithm may be implemented separately on these two sets.
Clustering based on Amount of Light. The LogLightMetric was modeled using a mixture of Gaussians. The number of Gaussians were chosen based on the BIC value. Referring to FIGS. 6( a ) and 6 ( b ) respectively, the histograms of the LogLightMetric on images shot without and with flash respectively is shown. FIGS. 7( a ) and 7 ( b ) show the Gaussian clusters learned on the LogLightMetric distributions. FIGS. 8( a ) and 8 ( b ) show the BIC values for a varying number of clusters.
Clustering based on DOF. In the next level, the Depth of Field may be modeled for distribution in the images. DOF depends on the aperture size, focal length and subject distance. But only some selected camera models (two out of the seven examined) have subject distance as a separate parameter in the Optical Meta layer. Generally indoor shots have lower subject distances than outdoor shots. Further, the amount of light in indoor and outdoor images varies widely. Employing known classifications techniques using light only, one may then be able to cluster images as either outdoor or indoor.
Given this exemplary initial classification, the image content may be estimated using aperture diameter and focal length. In one instance, given the parameters of an indoor photo, a short focal length, and low DOF, an image may be of particular objects, portraits etc, while one with a longer focal length and shallow DOF could be of a smaller target e.g., food, indoor decorations, babies, etc. Since focal length and aperture diameter are two independent parameters (the former related to the lens and the latter related to the aperture opening), they were modeled independently as a mixture of Gaussians. Thus for a particular log-light cluster L, there are F Gaussians for focal length and D Gaussians for diameter. Hence in the second level of the hierarchy, cluster L may be further sub divided into F×D clusters. In each of the cases the number of clusters is decided by the optimal BIC value. FIG. 9 shows the diameter and focal length Gaussians on some of the selected first level clusters both from Flash Fired and Flash Not Fired sets.
Interpretation of Unsupervised Classes
The 30 thousand image dataset was then divided into two parts of 20 thousand and 10 thousand images (randomly chosen). The unsupervised clustering process was used on the 20 thousand image set. The rest was kept aside for assigning class names and comparison with human induced classes. Some observations on the unsupervised clustering are as follows.
a. As discussed earlier, since Flash is a source of light which modifies the ambient light condition, images were separated out with and without flash. The hierarchical clustering algorithm may then be implemented separately on these two sets.
b. The exposure time and focal length distributions are highly skewed ( FIGS. 4( a ) and 4 ( c )). Less than 1% of the images have exposure times greater than 0.5 second. These images may then be filtered out and clustered them separately. They generally turn out to be images of night illuminations, fireworks etc. Due to the choice of the light metric, the clusters shown in FIGS. 9( a ) and 9 ( b ) represent images with differing amounts of ambient light. FIG. 9( a ) represents images shot in bright light, for example, daylight while FIG. 9( b ) represents images shot in low light conditions.
c. Most of the images in the dataset have been created by regular point and shoot digital cameras, which typically have wide angle lenses. FIG. 4( c ) shows that photos with a focal length greater than 100 mm are highly sparse (except that there is a peak at 300 mm, which is from a stream of photos of a sporting event). Photos with high focal length were separated out and modeled independently. FIG. 10( b ) shows the distribution of the diameter and focal lengths for this set. It may interest some to note that they also have a very high aperture diameter (>30 mm). This is because images with telephoto lenses have very shallow DOF. Hence the aperture diameter is high.
d. In the second level of the hierarchy, clustering was done based on the diameter and focal length distribution. Clusters with low focal length, low diameter will have wide angle images with high DOF. Clusters with high focal length and large diameter will contain images of an object zoomed into (with shallow DOF).
e. FIG. 10 shows focal length aperture diameter scatter plots for two light clusters. FIG. 10( a ) is the plot for the second light cluster in images shot with flash. The vertical lines testify to the hypothesis that the focal length and diameters are independent optical parameters in camera. FIG. 10( b ) is the scatter plot for the focal length versus diameter scatter plot of photos chosen from the leftmost light cluster in FIG. 7( b ). It also has the sets of vertical lines. Further, some may find it interesting to see that points are arranged in straight lines of constant slope. Each of these constant slope lines correspond to an f-number (ratio between focal length and aperture). Also it is seen according to this analysis that high focal length images (>60 mm) rarely have low apertures. This may be intuitive because with high focal length people generally focus on a particular object and they need shallow DOF (high aperture) for that.
The Survey and Human Induced Classes
A survey was conducted about popular image classes generally shot by amateurs. The survey was conducted among roughly thirty people who were asked to come up with common class names they would assign to the images in their personal albums. The survey revealed that class names depend on the human perception and background knowledge of an image, for example, an image of people in a scenery can be classified as ‘outdoor activities’, ‘hikes/trips’, ‘people in landscape’, ‘group of people’ etc. From the feedback the fifty five most common class names were chosen for the study. These class labels were then assigned to two thousand images randomly selected from the 10 thousand image hold out set. Since the classes are not mutually exclusive, each image was assigned to as many classes as it seemed coherent to the person involved in tagging.
Comparison of Human Induced Classes and Unsupervised Clusters
With reference to FIG. 12 , to evaluate the effectiveness of the optical meta layer in classification of images, the unsupervised clusters may be compared with the human induced classes. The unsupervised clusters may be called: Optical Clusters and Human Induced Class Names as Human Classes. A mapping, F was performed between these two sets showing the correspondence between the optical clusters and human classes. Further, this mapping was defined as ‘soft’. Each edge between a Human Class and Optical Cluster has a weight. This weight signifies the strength of the belief of the correspondence. The weight was found by the following probabilistic framework.
Let HumClass be a discrete random variable over the set of Human Class indices, and OptClus be a discrete random variable over the set of Optical Cluster indices. Thus one may want to evaluate the conditional probability: P(HumClass|OptClus), to express the strength of correspondence between HumClass and OptClus. From the tagged dataset, there may be a set of images D i for each of the HumClass values i. Thus,
P ( HumClass | OptClus ) = P ( OptClus | HumClass ) P ( HumClass ) = P ( D i ɛ OptClus | HumClass i ) P ( HumClass i )
Thus the results can be expressed as a table of Log likelihoods between Optical Clusters and Human Classes [Table 1 which follows].
TABLE 1
Ranked human semantic concepts for each clusters.
Optical
Clusters
Human Induced Classes
OC1
Group of
Single Person
Portraits of
People (−2.1)
Indoors (−2.5)
People (−3)
OC2
People At
Views of
Public Places
Talk By
Dinner (−4.0)
Rooms/
Indoors (−7)
Speaker
Offices (−4.5)
(−14)
OC3
City Streets
Vehicles/Cars
Buildings/
Public
(−5.21)
(−5.3)
Architectures
Places
(−6)
Outdoors
(−6.3)
OC4
People In
Fireworks (−7)
Theaters/
Bars and
Auditoriums
Restaurant
(−8)
(−6.1)
OC5
Daily
Buildings/
People in front
Group of
Activities
Houses (−2.5)
of Buildings
People
Outdoors
(−5)
Outdoors
(−1.92)
(−7.2)
OC6
Signboards
Poster/
Outdoor
(−7.2)
Whiteboards
Decorations
(−8.1)
(−9.5)
OC7
Moonlit
Illuminations at
Birds Eye At
Stage
Scenes (−12)
Night (−13.4)
Night (−16)
Shows
(−20)
OC8
Indoor
Food (−16.2)
People at
Decorations
Meetings
(−15)
(−19.2)
OC9
Lake/Oceans
Mountains
Landscape/
People in
(−1.37)
(−1.5)
Scenery (−2)
Scenery
−2.67
OC10
Sunset (−3.2)
Silhouette
Illuminations at
(−4.5)
Night (−10)
OC11
Wildlife
Sports (−3.2)
Bird's Eye
Trees/
(−1.83)
View (−4.6)
Forests
(−6)
Interpretation of Results
The hierarchical unsupervised algorithm returned multiple sets of clusters. The first set is for images without flash. There are thirty three clusters in the set. Next is a set of twenty nine clusters for images with flash. There are two clusters for images with very high focal length (>100 mm) and six clusters for images with very high exposure time (>0.5 sec). Eleven optical clusters were selected and showed the most likely human induced class for each of them. Each row in the figure corresponds to an optical cluster (OC). OC 1 has predominantly indoor images shots with short focal length and low DOF (people posing for photo, portraits etc). OC 2 are indoor images with similar lights but longer focal length and larger DOF. OC 3 is in different lighting conditions altogether. It is a cluster of outdoor objects like streets, cars and buildings. OC 4 is of dark indoors like bars/restaurants or fireworks in dark outdoors. OC 6 is of outdoor objects which have been focused into. OC 7 is dark outdoors like moonlit scenes and illuminations or stage shows etc. OC 9 and OC 10 are of high focal lengths of which the ambient light in OC 9 (sceneries/landscapes) is more than OC 10 (sunsets). OC 11 is of images with very high focal lengths (sports/wildlife etc).
Annotation of Untagged Images
To explore the robustness of the algorithm for prediction of tags in untagged images, a set of images was collected which have not been used either for building the unsupervised model or for creating the human tagged set. For each test image the probability of each of the unsupervised cluster was found. Heuristically, the first ten clusters were chosen having largest probability. Next, for each cluster, the top five human induced classes were chosen and their probability weighted with the cluster specific probability. Mathematically, the process can be expressed as:
P ( HumClass i | TestImage ) = Σ k P ( HumClass i | OptClus k ) P ( OptClus k | TestImage ) .
P(OptClus k |TestImage) can be obtained using the parameters of the Gaussian and P(HumClass i |OptClus k ) has been generated by the tagged image set. The list may be ranked based on the conditional probability. In most cases, the probability decreases smoothly or by smaller steps until there is a sudden large drop. For example, FIG. 18 shows exemplary human induced classes for some test images until the likelihood drop. The results are presented in tabular format (Table 2) where an Image column 200 is comprised of test images that were run through the probability process and their respective annotation results can be seen in the column of Predicted Classes 300 . In one test sample image, Image 1 ( 205 ), annotations such as “Outdoor Night”, “People in Restaurants”, “Theater”, “Stage Show”, “Talk By Speaker”, “Portrait at Night”, and “Public Indoor Places” were generated before a drop-off threshold in likelihood of connection is reached.
The Automatic Annotation Framework
An automatic annotation framework may be based on the relevance model approach. Referring to FIG. 13 , a Bayesian network model is defined to show the interaction among content and contextual information in an image. An image (I) is treated as a bag of blocks and words generated from the same process. These blocks come from a finite set of block vocabulary and the words come from a finite set of word vocabulary. One way the blocks are generated includes dicing up each image in a training corpus into fixed sized square blocks. For each block, a number of low level features like color histogram, color moments, texture and edge histograms are computed. Assuming that a feature vector is of size (F) and there are (M) blocks in each image and (N) photos in the training corpus, a result of (MN) block scan be obtained. Using a k means algorithm on these (MN) blocks finds k representative blocks. So the out block vocabulary size is (K). One would assume all images have been generated by selecting some blobs from this vocabulary space. Hence, each image can be characterized by a discrete set of block numbers of size (M). By heuristically deriving a value for (K), for example, 500, the responses in a sample survey of thirty people who submitted common nouns for photos they shot came up with a vocabulary size of 50 words.
Referring to FIG. 13( a ), a Bayes Net model is shown. Assuming a given training corpus of images (T) (not shown), each image (I)ε(T) is represented by a vector of discrete values (B) of size (M) which denote which block from the vocabulary has been used to create the image. Also associated with each image is a set of words or annotations (W). Thus, (I)=(B,W). Automatic annotation can then be used to predict the (W)s associated with an untagged image based on (B). Thus, for an untagged image, the probability of a word being assigned to the image can be computed based on (B). Let (I) be the random variable over all images in the training corpus, (B) be the random variable over the block vectors and (W) be the random variable over the words. In the Bayes Net model, (B) becomes the observed variable. The conditional probability of a word given a set of blocks is computed according to the following equation:
P ( w|B )=Σ I P ( w,I|B )=Σ I P ( w|I,B ) P ( I|B )αΣ I P ( w|I ) P ( B|I ) P ( I )
P(w|I) and P (B|I) can be learned from the training corpus after adequate smoothing. This would be a baseline model however; it does not consider the contextual information which is present in a digital photo. Hence, referring to FIG. 13( b ), a model is proposed integrating both content and context. The content and contextual information is assigned to images in optical clusters (O) using an untagged image database. Whenever a new image (X) comes, it may be assigned to a cluster O j having a maximum value for P(X|O j ). Here O is a random variable over all clusters and it is observed. Thus the probability of a word in a block vector given the pixel feature blocks and the optical context information can be computed as in the following equation:
P ( w|B,O )=Σ I P ( w,I|B,O )=Σ I P ( w|I,B,O ) P ( I|B,O )Σ I P ( w|I ) P ( B,O|I ) P ( I )=Σ I P ( w|I ) P ( B|I ) P ( O|I ) P ( I )
Each (0) is represented as a Gaussian cluster whose parameters are learnt using the algorithm for the clustering model.
Indoor/Outdoor Classification
To show the efficacy of the Optical Meta Layer, a two class classification problem may be solved. First, the camera parameters may be used to classify photos either as indoor shots or outdoor shots. As a baseline, the raw camera parameters (focal length, exposure time, flash, diameter, ISO value) are used. Next the latent variable LogLightMetric for classification is used. As shown in Table 3, the accuracy improves by 3% and the F-Measure improves by 5% if the latent variable is used for classification. Also one may see that the optical metadata are by themselves quite efficient in distinguishing between indoor and outdoor shots.
TABLE 3
Results of Indoor Outdoor classification
using Optical Metadata only
Mean
Mean
Absolute
F-Measure
F-Measure
Type of Model
Accuracy
Error
Indoors
Outdoors
Raw Camera Parameters
90.5
0.13
0.89
0.90
LogLightMetric
93.86
0.09
0.93
0.95
TABLE 4
Automatic Annotation on the Entire Vocabulary Set
Type of Model
Mean Precision
Mean Recall
Only Content Data
0.46
0.31
Both Content and Context
0.56
0.35
Next the results of automatic image annotation may be shown, first using only image features and then using both image features and optical context information. For each photo in the test set, the algorithm finds a probability distribution over the entire set of vocabulary. Heuristic techniques choose the top five words from them as the annotations for an image. If the ground truth annotations (tagged by humans) match any of the predicted annotations there is a hit, else there is an error. Precision for a particular tag is the ratio between the number of photos correctly annotated by the system to the number of all photos automatically annotated with the tag. Recall is the number of correctly tagged photos divided by the number of photos manually annotated with that tag. Table 4 shows the mean precision and mean recall for the entire set of fifty tags in vocabulary set. Table 5 following shows the mean precision and mean recall values for the twenty most popular words in an example vocabulary set (which have at least 40 representative photos in the training set). The top row shows the results for the model in FIG. 13( a ) and the bottom row shows the results for the model proposed in FIG. 13( b ).
TABLE 5
Automatic Annotation on the Popular Vocabulary Set
Type of Model
Mean Precision
Mean Recall
Only Content Data
0.59
0.46
Both Content and Context
0.76
0.60
In FIGS. 14 and 15 automatic annotations are shown on some test photos where “original tags” are the tags inserted manually. The set Auto Annotation 1 are the tags predicted by the baseline model 13 ( a ). The set Auto Annotation 2 are the tags predicted by using both content and context information 13 ( b ).
In an exemplary embodiment, context information can be used to narrow down the search space for image retrieval. Keyword based image retrieval can be done in one of two ways in a searchable environment. If all images in the database have been annotated with words from the vocabulary along with the corresponding probabilities, one can just retrieve the images having the query tag with a probability higher than a cutoff. In the other approach, one can translate the query words into image feature space. Since a joint distribution between blocks and words may be already learned, the most likely block vector can be found given query word(s). This blob vector may be used to find the most likely photos. In both cases searches may be through the entire image database or using the optical metadata under another embodiment of the present invention, the retrieval engine may be guided to particular clusters.
Optical clusters previously generated (for example, those shown in FIGS. 6 and 7 ) may be used as representative clusters. One advantage is that these clusters can be computed with minimal computational resources and can be readily interpreted. The tagged photo set was divided into training and test sets. For each photo in the training set the most likely Gaussian cluster was found and assigned all the tags of this photo to that cluster. So after iterating through the entire training set, there is a joint distribution between the tags and optical clusters. Then for each word, clusters were chosen which contribute to the top P % of its probability mass. These clusters were marked as the only ones generating all the photos with the tag. For each tagged image in the test set the most likely cluster was found. Experiments with forty different random samples of training and test images were performed. For P=70%, only 30% of the entire image database needed scanning (assuming that each cluster has equal weight in the image space). The errors on all the images and tags on the test set were computed. Table 6 shows the mean errors for some tags across all test samples. The mean average error for all tags across forty different samples is 0.18.
TABLE 6
Mean Errors for Search
Tag
Mean Error
Buildings/Monument
0.14
Sunset
0.15
Illuminations
0.15
Beach
0.28
Indoor Group Photo
0.10
Vehicle
0.14
Indoor Artifacts
0.27
Decrease in Search Space
The inferences obtained using the Optical Meta Layer in the present invention can significantly decrease the space for image search. The proposed exemplary algorithms could be used in the top level of a hierarchical retrieval algorithm. This can improve the efficiency by decreasing the search time and also remove false positives by guiding the algorithm to the relevant clusters. For instance, the pixels in a photo of a garden and in a photo of an outdoor sporting event (in a field) may be very much the same. It might be difficult to distinguish them using color histograms. But the optical parameter ‘focal length’ will guide the retrieval algorithm in the correct clusters, as the focal lengths of these two types of images are likely to vary widely. For instance, some human induced classes were chosen and their distribution over a set of optical clusters was found as seen in FIG. 11 . The horizontal axis denotes the focal length index of Optical Clusters. The ambient light in clusters decreases from left to right on the horizontal axis. The DOF changes in cycles on the horizontal axis.
This is due to the multimodal nature of the distributions. For instance, referring to FIG. 16 , the photos for city streets can be shot in different lighting conditions, but they may have same DOF distribution. The peaks correspond to different lights but similar DOF. As another example, indoor parties/people at dinner are typically shot in low light condition. This may explain the peaks towards the right end of the spectrum. ‘Public places indoors’ is a broad class. Hence the classes are spread throughout the spectrum.
Next the top optical clusters were selected which together contribute to 85% of the mass for a particular human induced class. In the following Table 7, the ratio of the total weight of these clusters is shown relative to the entire search space. The ratio was found separately for spaces of photos with flash and for photos without flash. For most of the image classes the search space was narrowed down to 30-40% of the entire space using optical meta data alone. Most of the classes related to nature or outdoor city life (landscape, city streets, mountains etc) are found concentrated in the images without flash. Portraits are generally shot in bright lights and not in dark nights. Hence the distribution of portraits in the set of images with flash is low. Wildlife photos are shot with high focal lengths (which were modeled separately and are not shown here). This may explain their low concentrations in both the image sets. Certain classes of images (people at dinner, group photos at night, and various night scenes) are more likely to be shot with flash. This explains their concentration in the set of images with flash. Some classes of photos can be pretty broad and can be shot both with and without flash. These include indoor parties/special occasions, night life, illuminations, public places indoors (theaters, auditorium).
TABLE 7
Search space decrement for human image concepts
Fraction of Image
Fraction of Image
Class Names
Space W/O Flash
Space With Flash
City Streets
0.20896
0.066552
Building/Architecture
0.244246
0.068718
Scenery/Landscape
0.362119
0.042299
People in Scenery
0.42766
0.340374
Oceans/Lakes
0.362119
0.045448
Mountain
0.330615
0.040133
Portraits Indoors
0.261055
0.032708
Portraits Outdoors at Day
0.240372
0.052366
Group Photo Indoors/at
0.202701
0.341745
Night
Group Photo Outdoors at
0.42766
0.027392
Day
People on Streets
0.253875
0.068718
People in front of
0.364461
0.372224
Building/Architecture
Flowers/Plants
0.235974
0.052366
Wildlife
0.121561
0.021597
Trees
0.360587
0.025947
Bird's Eye View
0.365993
0.006289
Furniture/
0.25317
0.027392
Appliances
Pets
0.230677
0.047504
Indoor Daily Life
0.246327
0.034874
Indoor Decorations
0.365706
0.034874
Views of Rooms
0.182711
0.027392
Illumination at Night
0.396726
0.33838
Garden
0.267731
0.029787
Indoor Parties/
0.039203
0.302586
Special Occasions
Public Places
0.268222
0.034874
Indoors
Sunset
0.336539
0.021368
Sky
0.220874
0.032708
Silhouette
0.312646
0.044176
Beach
0.266012
0.063015
Outdoor Decorations
0.356489
0.032708
People at Dinner
0.009253
0.032708
Public Places
0.298612
0.33838
Indoors
Night Scenes
0.329343
0.475733
FIG. 17 schematically represents a series of steps involved in a method 100 for classifying digital images using optical parameters according to another embodiment of the invention, wherein step 110 may involve assembling a set of commonly associated classes. The classes may be formed generally as described hereinabove, for example, with reference to FIG. 12 and Table 1.
As a non-limiting example, a set of commonly associated classes may be formed using the results of a human induced feedback, for example a survey.
Step 120 may involve extracting and analyzing optical meta data and pixel values from an image file selected from a database of input photos. As a non-limiting example, information such as exposure time, focal length, f-numbers, and flash presence ( FIG. 4 ) may be analyzed for optical characteristics and the results stored.
Step 130 may involve applying an algorithm to the optical metadata and pixel values to predict probable grouping (meaningful clustering) with other image files having similar measurements. For example, FIGS. 6 , 7 , and 9 depict clustering of images based on Gaussians of similar ambient light characteristic results.
Step 140 may involve assigning classification tags to image files to map probable class tags based on results of algorithms such as those in Step 130 . With reference to FIG. 12 , one exemplary mapping model depicts various cluster groups associated with a sample of human induced classes.
Step 150 may involve classifying digital images according to a set of associated classes using classification tags such as those in Step 140 . With reference to FIGS. 14 and 15 , digital images may be assigned multiple tags and classified into multiple classifications when image elements satisfy a probable relation to the various classifications.
Step 160 may involve retrieving images with desired classifications within a probability of being related to a query word. Referring to FIG. 13 , a Bayesian model may be used to assign a word to an image using a probability equation based on content and contextual information. As described hereinabove, probability algorithms may be used to retrieve images satisfying a cutoff value. Optional Step 165 divides an image into representative blocks of pixel features and optical context information where blocks within a probability cutoff are formed into block vectors. Optional Step 167 then clusters together images within a maximum probability value for a word matching the block vector. Optional Step 170 provides a searchable environment for an image using keywords that satisfy the probability value on Step 167 .
Thus, while the optical meta layer constitutes only a few bytes of information in a standard 3-4 MB digital camera photo, these bytes contain hidden information about the content of the other layers (Pixel and Human Induced). Further they can be easily extracted and processed without too much computational cost. Although the invention has been described primarily with respect to the optical meta layer to generate inferences among digital images, the present invention is not meant to be limited in this respect. For instance, the information from a human induced meta layer (if available) can also help boost the inferences derived from the optical meta layers. Additionally, the inferences in the derived meta layer may be obtained from the joint distribution of optical, temporal, human induced meta layers.
It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A method of classifying and organizing digital images utilizing optical metadata (captured using multiple sensors on the camera) may define semantically coherent image classes or annotations. The method defines optical parameters based on the physics of vision and operation of a camera to cluster related images for future search and retrieval. An image database constructed using photos taken by at least thirty different users over a six year period on four different continents was tested using algorithms to construct a hierarchal clustering model to cluster related images. Additionally, a survey about the most frequent image classes shot by common people forms a baseline model for automatic annotation of images for search and retrieval by query keyword.
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TECHNICAL FIELD
[0001] The present invention is related to automotive throttle control systems. More particularly, the present invention is concerned with throttle limiting in a variety of cruise control and power take-off mechanizations.
BACKGROUND OF THE INVENTION
[0002] Cruise control systems are employed extensively in modern automobiles. Conventional cruise control systems regulate vehicle speed to a an operator set speed in accordance with well known PID speed controllers. Adaptive cruise control systems are also known wherein the following distance of an adaptive cruise vehicle relative to a preceding vehicle is controlled. The following distance may be a set distance or a variable distance as a function of vehicle speed. Vehicle separation may be determined, for example, by radar, infrared, ultrasonic or other means.
[0003] Speed control or following distance of such conventional or adaptive cruise control equipped vehicles ultimately depends upon the control of drive torque produced by the vehicle. In internal combustion engines, torque is generally a function of the air ingested by the cylinders (intake air) among other factors. Intake air is controlled by throttling an air passage upstream of the cylinders.
[0004] Vehicular power take-off (PTO) systems are known which provide for a mechanical output from an internal combustion engine or portion of the vehicle drivetrain to drive accessory loads such as electrical generators or mechanical or hydraulic apparatus. PTO is operator invoked generally in accordance with a selected engine speed setting. Speed control of the engine ultimately depends upon the engine torque required to provide the needed PTO torque requirements at the selected set speed. As previously stated torque is generally a function of intake air ingested by the internal combustion engine. And, intake air is controlled by throttling.
[0005] Mechanically linked throttle systems are known wherein intake air is throttled in substantial accordance with the throttle pedal position under control of the vehicle operator. Such mechanically linked systems similarly employ mechanically linked throttle actuators to establish position authority over the throttle valve for cruise control and PTO applications—typically by a valve controlled vacuum actuator and cabled arrangement. Electronic throttle control systems are known which mechanically decouple the throttle valve from the throttle pedal. Such systems generally employ throttle pedal position sensing and stepper motor actuation of a throttle valve. Throttle valve position sensing is also generally employed in both mechanically linked and electronically controlled throttle systems.
[0006] Throttle authority is conventionally set to an upper limit of substantially 100% (fully open) when a cruise control or PTO system is activated. It is generally desirable to provide for broad throttle authority during cruise control since vehicle throttle requirements can vary substantially with load, grade and altitude. It is known in cruise systems, for reasons including driveability considerations, to provide a throttle limit during resume and acceleration cruise operations. Such limits are known to be substantially fixed throttle position settings and may be a setting substantially in excess of a current throttle position.
[0007] Such broad limits on throttle authority may in the event of certain control corruption necessitate operator intervention in order to manage the throttle as desired to maintain the operator's objective of vehicle speed or following distance in a cruise control mode or engine speed in a PTO mode. Generally, however, it is desirable to minimize the amount of operator interaction that is required, even in the event of a control corruption. Therefore, a need exists to limit the required operator intervention required in the event of control corruption while at the same time not unnecessarily limiting throttle authority.
SUMMARY OF THE INVENTION
[0008] A vehicle includes a throttle controlled internal combustion engine. In accordance with one aspect of the present invention, throttle changes are controlled by providing a throttle actuation limit substantially corresponding to a throttle pedal angle and providing a requested throttle actuation corresponding to an automated throttle position control such as conventional or adaptive cruise or power take-off. Throttle rate of change is limited when the requested throttle actuation is above the throttle actuation limit.
[0009] In accordance with another aspect of the present invention, a method for controlling a throttle in an internal combustion engine includes providing a first throttle actuation request substantially corresponding to a throttle pedal angle. A second throttle actuation request corresponding to an automated throttle position control is likewise provided such as from a conventional or adaptive cruise control system of a power take-off system. Throttle changes are effected substantially in accordance with the first throttle actuation request when said first throttle actuation request exceeds the second throttle actuation request. Throttle changes are rate limited when the first throttle actuation request does not exceed the second throttle actuation request.
[0010] Generally, the automated control maintains authority over the throttle position when the requests therefrom are within expected ranges as exemplified in the chosen calibrations for the rate limiting. Only when excessive rates of throttle change are being requested will the rate limiting affect the system. And even then, throttle changes are generally permitted up to the full authority of the throttle control. Exceptions are envisioned such as when continued throttle changes result in errors in other affected controlled operating parameters such as vehicle speed in a conventional set speed cruise control system. Throttle pedal authority is always provided such that operator requests—as discerned from throttle pedal actuations—in excess of the requests from the automated throttle position controls take precedence.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0012] FIG. 1 is a block diagram of an exemplary automotive internal combustion engine and controller implementation of the present invention;
[0013] FIG. 2 is a controller block diagram of preferred engine control module for implementation of the present invention;
[0014] FIG. 3 is a flow diagram representing certain exemplary steps of a first embodiment of the present throttle control invention implemented as part of an automotive set speed cruise control system;
[0015] FIG. 4 is a flow diagram representing certain exemplary steps of a second embodiment of the present throttle control invention implemented as part of an automotive adaptive cruise control system;
[0016] FIG. 5 is a flow diagram representing certain exemplary steps of a third embodiment of the present throttle control invention implemented as part of an automotive power take-off control system;
[0017] FIG. 6 is a plot of throttle area versus time illustrative of various throttle requests and limits in accordance with the second embodiment of the present invention as represented in FIG. 4 ; and
[0018] FIG. 7 is a plot of throttle area versus time illustrative of various throttle requests and limits in accordance with the first embodiment of the present invention as represented in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Reference is now made to the figures and particularly beginning with FIG. 1 an engine control module (ECM) 36 is a microcontroller based device with standard control and logic circuitry and standard memory devices including read only memory devices in which are stored a plurality of routines for carrying out engine control and diagnostic operations. Each routine includes a sequence of instructions which are executed by the microcontroller following preestablished engine events or on a timed basis. Such routines, which may be repeatedly executed following each successive engine cylinder event while the engine is operating, include fuel control and spark timing routines for generating and issuing a fuel command FUEL and a spark timing command EST, respectively. These commands are provided to respective fuel controllers and ignition controllers (not separately illustrated) for controlling fuel delivery and ignition timing for each cylinder event.
[0020] An operator-controlled accelerator pedal 24 , a.k.a. throttle pedal, is manually depressed by a vehicle operator to indicate a desired engine operating level. The degree of depression of the pedal away from a rest or low angle position is transduced by conventional potentiometric position sensor 26 into output signal PPS, which is provided as a control input to ECM 36 as an indication of a desired engine operating level. Throttle actuation and throttle position sensing is accomplished by electronic throttle body throttle actuation hardware and throttle position sensing hardware (ETB & TPS) 131 as follows. An intake air valve position command is converted into a pulse width modulated (PWM) actuator drive signal on line 46 for commanding output shaft of actuator 18 toward a desired rotational position. Intake air valve position signal TP is received by the ECM 36 for closed-loop control operations. Alternatively, a separate throttle control module (not shown) includes a conventional controller architecture of such well-known elements as a central processing unit and input/output circuitry. Generally, the throttle control module receives engine operating condition information from the ECM 36 across a bi-directional serial data link, and receives transducer signals and generates, through execution of a series of stored instructions in the form of a control routine, an intake air valve position command (i.e. actuator drive current signal) for commanding output shaft of actuator 18 toward a desired rotational position. In such arrangement, signal TP is received by the throttle control module for closed-loop control operations.
[0021] Intake air is passed through intake air bore 12 past mass airflow meter 14 of the thick film or hot wire type for transducing engine intake air mass flow rate into output signal MAF. An electronically-controlled intake air valve 16 for example of the butterfly or rotary type is disposed in intake air bore 12 and rotates therein to vary a degree of restrictiveness of the intake bore 12 to intake air passing therethrough. An electromechanical actuator 18 , for example of the DC motor or stepper motor type includes a rotatable output shaft (not shown) mechanically linked to the valve 16 , such as through a gear assembly (not detailed). The rotational position of the output shaft of actuator 18 is controlled through variation in an electrical current command issued by ECM 36 , for example through pulse width modulation control of the four gates of a commercially available full H-bridge (not shown) for bi-directional current control. Through timed variation in the magnitude of the current command, high resolution, highly responsive control of engine intake air valve position is provided for engine intake air rate control. Actuator 18 may be any commercially-available high performance electromechanical actuator that provides high performance dynamic positioning, as is well-established as required in electronic throttle control applications under certain engine operating conditions, such as high engine intake air rate (high engine load) operating conditions. The rotational position of the intake air valve 16 is transduced by potentiometric position sensor 20 of any conventional type into output signal TP.
[0022] The intake air passing across intake air valve 16 is received in an intake manifold 21 for distribution to intake runners of a plurality of engine cylinders (not shown). Intake air absolute pressure in the intake manifold 21 is transduced by conventional pressure transducer 22 into output signal MAP. Ambient barometric pressure is transduced by a conventional barometric pressure sensor (not shown) or, alternatively, under specified operating conditions, such as conditions in which the pressure drop across the intake air valve 16 is substantially zero, is set to the pressure value represented by signal MAP.
[0023] The intake air is combined with an injected fuel quantity and delivered to engine cylinders for combustion therein for reciprocally driving pistons (not shown) within the cylinders, the pistons being mechanically linked to an engine output shaft 30 to rotatably drive the output shaft. Engine position is transduced by a rotation sensor (EPS) 32 , for example a conventional Hall effect or variable reluctance transducer, positioned in close proximity to the output shaft to transduce passage of encoded patterns of teeth or notches (not shown) formed on the output shaft into cycles of transducer output signal. From EPS 32 can be derived engine speed as conventionally practiced in the art of engine controls. Gasses produced in engine cylinders during the combustion process are guided out of the cylinders and through exhaust gas conduit 34 .
[0024] The ECM 36 receives a plurality of input signals including the described transducer output signals MAF, MAP, EPS, and BARO, and, through execution of the described routines, generates command FUEL and command EST, and other control commands including for throttle valve positioning in accordance with an electronic throttle control and the method of the present invention.
[0025] Reference is now made to FIG. 2 wherein a preferred controller architecture for implementing the various embodiments of the present invention is illustrated. ECM 36 is a microprocessor based controller comprising such common elements as read only memory ROM, random access memory RAM, electrically programmable read only memory EPROM, high speed clock, analog to digital (A/D) and digital to analog (D/A) circuitry, and input/output circuitry and devices (I/O) and appropriate signal conditioning and buffer circuitry. In the exemplary embodiment, ECM 36 comprises a dual microprocessor system designated as the main control processor (MAIN) 103 and motor control processor (MCP) 105 . MAIN and MCP provide, as previously described, a variety of control and diagnostic functions related to an internal combustion engine. ECM functions to directly acquire data from a variety of sensors and other electronic modules and directly control a variety of actuators to accomplish the engine control objectives, including throttle control in accordance with throttle pedal position, or automated throttle controls such as in adaptive and conventional cruise system and power take-off systems, including throttle limiting controls in accordance with the present invention. Inputs and outputs may be in the form of discrete data signals or via bussed or networked data exchanges with other modules. For example, a vehicle speed sensor (VSS) 113 provides a discrete signal corresponding to vehicle road speed as may be determined in accordance with a conventional rotation sensor providing a periodic signal proportional to vehicle speed. Such sensor may be positioned to sense rotation speed of the transmission output member or alternatively a vehicle speed signal can be determined from one or more discrete wheel speed sensors as well known in the art. Engine position sensor EPS 32 similarly provides a discrete signal as previously described.
[0026] Various other modules such as cruise module (CRZ) 107 , adaptive cruise control module (ACC) 109 and power take-off module (PTO) 111 may interface with ECM via a controller area network (CAN) bus thus allowing for communication of control parameters and commands between the various modules. A preferred communication protocol for automotive applications is the Society of Automotive Engineers standard J1939. The CAN bus and appropriate protocols provide for robust messaging and multi-controller interfacing between the ECM, CRZ, ACC and PTO modules and other controllers such as antilock brake and traction controllers. ETB & TPS 131 is illustrated in block format but does, as described previously, include a throttle valve position actuator and throttle position sensor. CRZ and ACC modules are shown in broken line format indicating alternative application—that is cruise control would be implemented by one or the other module.
[0027] MAIN includes a variety of control modules shown in block format. These modules are functional modules and represent software routines for providing various specialized control and diagnostic routines as described further herein below.
[0028] Cruise control block (CRZR) 117 provides for vehicular cruise functionality and relies upon data from CRZ module 107 or ACC module 109 . CRZ module 107 accepts a plurality of switch inputs such as ON/OFF, RESUME-SPEED/ACCELERATE, SET-SPEED/COAST, CANCEL AND BRAKE. CRZ module 107 monitors the switch states and their transitions, performing signal conditioning and pre-processing including conventional debouncing, and exchanges this data with CRZR 117 of the main control processor of ECM 36 . CRZR receives data from CRZ module 107 and interprets appropriate cruise states and settings such as enabled or disabled, vehicle speed settings and incremental or ramped changes thereto. ACC module 109 accepts a plurality of switch inputs such as ON/OFF, RESUME/ACCELERATE, SET/COAST, CANCEL AND BRAKE. Additionally, ACC module may also receive an adjustable input such as from a potentiometric input setting adapted for use in establishing a variable setting for following distance. In an adaptive cruise system, the RESUME and SET switches may only effect their functions of establishing a following distance where there is an in-range preceding vehicle. ACC module 109 monitors the switch states and their transitions, performing signal conditioning and pre-processing including conventional debouncing, and exchanges this data with CRZR 117 of the main control processor of ECM 36 . CRZR receives data from ACC module 109 and interprets appropriate cruise states and settings such as enabled or disabled, set following distance, resume to a set following distance, accelerate, etc.
[0029] Power take-off block (PTOR) 119 provides for vehicular power take-off functionality and relies upon data from PTO module 111 . PTO module 111 accepts a plurality of switch inputs such as ON/OFF, SET1 and SET2. Actuation of SET1 and SET2 switches effect respective calibrated engine set speeds upon a first actuation, effect set speed increments and decrements, respectively, upon subsequent momentary actuations, and effect set speed ramping when actuated and held. PTO module 111 monitors the switch states and their transitions, performing signal conditioning and pre-processing including conventional debouncing, and exchanges this data with PTOR 119 of the main control processor of ECM 36 . PTOR receives data from PTO module 111 and interprets appropriate power take-off states and settings such as enabled or disabled, engine speed settings and incremental or ramped changes thereto.
[0030] Vehicle speed block (VSPR) 123 receives discrete vehicle speed signal from VSS 113 as previously described. VSPR 123 provides conventional vehicle speed signal processing including signal conditioning and filtering of raw signal data and provides vehicle speed (Nv) for use in the engine control routines of the present invention.
[0031] Engine speed block (EPSR) 125 receives discrete engine rotation signal from engine rotation sensor EPS 32 as previously described. EPSR 125 provides conventional engine rotation signal processing including signal conditioning and filtering of raw signal data and provides engine speed (Ne) for use in the engine control routines of the present invention.
[0032] Cruise control block CRZR 117 provides a cruise throttle area request (CRZ_area_req) in accordance with the respective requests from CRZ module 107 or ACC module 109 embodied in the respective module switch states and transition data. CRZR 117 also provides, in the case of set speed control, a cruise vehicle speed request (CRZ_Nv_req). CRZ_area_req and CRZ_Nv_req are provided to throttle position control block (TPSR) 121 for use in the throttle control of the present invention. Power take-off block PTOR 119 provides a power take-off throttle area request (PTO_area_req) and power take-off engine speed request (PTO_Ne_req) in accordance with the request from PTO module 111 embodied in the PTO module switch states and transition data. PTO_area_req and PTO_Ne_req are provided to throttle position control block TPSR 121 for use in power take-off throttle and engine speed control of the present invention. Vehicle speed block VSPR 123 provides a vehicle speed signal Nv in accordance with the raw speed signals from VSS 113 . Engine speed block EPSR 125 provides an engine speed signal Ne in accordance with the raw speed signals from EPS 32 . Vehicle and engine speed signals Nv and Ne, respectively, are provided to throttle position control block TPSR 121 for use in various throttle controls as previously mentioned, including the throttle limiting controls of the present invention.
[0033] Throttle position control block TPSR processes the inputs described in establishing a desired throttle position signal which is provided to electronic throttle control block (ETC) 127 . Electronic throttle control block also receives intake air valve position signal TP and, through closed-loop control, establishes a intake air valve position command signal on line 133 . Intake air valve position command signal is provided to motor control processor where it is converted into a pulse width modulated (PWM) actuator drive signal. In accordance with a preferred implementation, however, intake air valve position command is scrutinized in accordance with a redundant implementation of the throttle control routine within throttle limit block (TLIM) 129 of the present invention as further described herein below. Further, in accordance with the preferred redundant implementation of the throttle control of the present invention, the described outputs from the main control processor MAIN blocks—i.e. CRZR, PTOR, TPSR, VSPR and EPSR—to wit, CRZ_Nv_req, CRZ_area_req, PTO_Ne_req, PTO_area_req, desired throttle position, Nv and Ne, are provided to the motor control processor MCP 105 .
[0034] In addition to the conventional steps of determining the desired throttle position signal in accordance with the various cruise, adaptive cruise or power take-off requests, the present invention, in various embodiments to be described independently with respect to conventional cruise, adaptive cruise and power take-off controls, provides for throttle limiting functionality that generally rate limits throttle changes while maintaining throttle pedal authority when requested by the vehicle operator and otherwise does not limit throttle authority for the respective active control, e.g. cruise, adaptive cruise or power take-off. Turning now to FIG. 3 a routine representing program steps particularly related to the throttle control of the present invention as relates to a conventional cruise control system effective to control vehicle speed substantially to a set speed is shown. This routine, as well as all of the routines of the various embodiments to be described, is part of a much larger set of instructions utilized in the overall control and diagnosis of the engine. The routines are preferably executed in a loop such as upon a timer interrupt but may also be executed in other fashions such as by way of event based interrupts if appropriate. A loop time no greater than about 50 milliseconds will effect a smooth control that is transparent to the vehicle operator. In a preferred implementation, the loop is executed in a 12.5 millisecond loop.
[0035] Step 11 represents steps executed for the purposes of initializing various registers and variables. Certain of the steps may be executed upon power up only, or through the first interrupt only, for example to seed initial variable values. At step 13 a pedal based throttle limit (Pedal_lim) is calculated in accordance with the sensed throttle pedal position as invoked by the vehicle operator. Such Pedal_lim essentially follows the operator's actuation of the throttle pedal. The position transduced from the position sensor 26 ( FIG. 1 ) is thereby used to establish Pedal_lim at some finite value in terms of throttle area. All throttle limits in this conventional cruise control embodiment, and in the adaptive cruise control and power take-off embodiments of this invention, are in terms of throttle area; however, it will be recognized by one skilled in the art that throttle position is an alternate metric that could be used in place thereof. Next, step 15 represents the determination of the status of the cruise control system. In the system architected as described, the various cruise switch inputs are used in an inferentially based determination of whether cruise control is active. If cruise control is not active, control passes to step 27 whereat the final throttle limit (LIM) is set to Pedal_lim, effectively providing throttle authority to the operator in accordance with the actuated throttle pedal position. An active cruise control system will result in step 15 passing control to step 17 whereat Pedal_lim is compared to the requested cruise throttle area request CRZ_area_req. An additional dead band offset (K) is added to CRZ_area_req for hysteretic stability purposes. Where Pedal_lim is not less than CRZ_area_req, step 27 is executed to set LIM to Pedal_lim, effectively providing throttle authority to the operator in accordance with the actuated throttle pedal position. If, however, Pedal_lim is less than CRZ_area_req, rate limiting is invoked as applied to throttle position changes.
[0036] With reference to step 19 , rate increment and decrement values, Rate_up and Rate_dn respectively, are set to values in accord with the current engine speed Ne and vehicle speed Nv operating point. The Ne/Nv ratio effects consideration of the current transmission speed ratio and resultant vehicle performance characteristics on setting an appropriate rate limit increment. Step 21 next compares Nv to the cruise vehicle speed request CRZ_Nv_req. Where Nv is less than CRZ_Nv_req, an increasing throttle is expected in accord with the cruise speed control objective of attaining the requested cruise vehicle speed and step 23 is executed. At step 23 , LIM is set in accord with the smaller of a limit calculated at a rate corresponding to the rate limit increment Rate_up or the cruise throttle area request. The rate limit is established by adding the prior control loop final limit (LIM_old) to the rate limit increment Rate_up whereas the limit corresponding to the cruise throttle area request is established as CRZ_area_req plus a dead band offset K. In effect, at increasing throttle, LIM substantially tracks the cruise requested throttle up to a predefined rate of requested increase whereat the rate of throttle change is limited at that rate. Control then passes to step 29 which is executed prior to any exit of the routine to set LIM_old to the current limit LIM for use in subsequent control loops.
[0037] If at step 21 Nv is not less than CRZ_Nv_req, a decreasing throttle is expected in accord with the cruise speed control objective of attaining the requested cruise vehicle speed and step 25 is executed. At step 25 , if the operator has requested through throttle pedal depression a throttle position in excess of that requested by the cruise control, LIM is set to Pedal_lim to effectively provide throttle authority to the operator in accordance with the actuated throttle pedal position. Otherwise, LIM is set in accord with the smaller of a limit calculated at a rate corresponding to the rate limit decrement Rate_dn or the cruise throttle area request. The final rate limit value is established by subtracting the rate limit decrement Rate_dn from the prior control loop final limit (LIM_old) whereas the limit corresponding to the cruise throttle area request is established as CRZ_area_req plus a dead band offset K. In effect, at decreasing throttle, LIM substantially establishes a throttle decrease limit until the cruise requested throttle falls below the limited throttle value whereafter decreasing throttle authority is given to the cruise throttle area request. Control then passes to step 29 which is executed to set LIM_old to the current limit LIM for use in subsequent control loops.
[0038] FIG. 7 illustrates various limit scenarios in accord with the conventional cruise control related embodiment just described with respect to the flow diagram of FIG. 3 . In FIG. 7 , the line labeled 75 represents the vehicle set speed of the cruise control and line labeled 77 represents actual vehicle speed. These speed lines 75 and 77 are not separately scaled with respect to the vertical axis of the graph as the values thereof are not critical to the present illustration; rather, they are instructive in providing the relative speed error, i.e. difference between set speed 75 and vehicle speed 77 against the same time scale along the horizontal axis of the graph. Cruise throttle area request, CRZ_area_req, is labeled 73 , throttle pedal limit, Pedal_lim, is labeled 79 and the final throttle area limit, LIM, is labeled 71 . Various time progressions of the throttle control of the present invention appear as alphabetic labels below the horizontal axis of the graph and will be referred to in the various illustrations herein below.
[0039] Beginning with the interval from time A to time B it can be seen that the cruise throttle area request 73 is above the pedal based throttle limit 79 but is increasing substantially at a first rate. This rate, however, is greater than the allowed rate by the limit control and hence the final limit 71 increases at a rate that is less than the requested rate. Since the cruise throttle area request is greater than the pedal based throttle limit, the cruise request has authority and the limit is set in accord therewith. An extreme rate of change in the cruise throttle area request is illustrated (time C). Such excessive changes might be consistent with a corruption in the integrity of the cruise throttle area request due, for example, to a hardware anomaly. However, the limit control of the present invention provides a final throttle rate limit 71 (interval C-D). The throttle responds to the excessive cruise throttle area request at the limited rate and eventually the vehicle speed exceeds the set speed (time D). This condition results in the throttle limit control applying a rate limit having a negative slope to reduce available throttle and attenuate the speed error. Vehicle speed reduces to substantially set speed (time E) and thereafter undershoots the set speed. This condition results in the throttle limit control applying a rate limit having a positive slope to increase available throttle and attenuate the speed error. This process can be seen to repeat while the throttle attempts to respond to the excessive cruise throttle area request 71 (interval C-G). At time G, the pedal based throttle limit 71 step increases significantly such as in response to the operator's request. The cruise throttle area request is shown substantially simultaneously dropping in step fashion even below the former pedal based throttle limit. Here, the throttle limit control of the invention provides a limit that substantially tracks the throttle pedal actuation. At time H, the throttle pedal authority drops stepwise to its former setting such as in response to the operator's request. At this point, the cruise throttle area request 73 is below the pedal based throttle limit and the final limit 71 is established substantially in accord with the pedal based throttle limit. At time I, the cruise throttle area request recovers close to the pedal based throttle limit and then surpasses it. The final limit then increases in accordance with the rate limit.
[0040] Turning now to FIG. 4 a routine representing program steps particularly related to the throttle control of the present invention as relates to an adaptive cruise control system effective to control following distance substantially to a set following distance, not to a set speed. Step 31 represents steps executed for the purposes of initializing various registers and variables. Certain of the steps may be executed upon power up only, or through the first interrupt only, for example to seed initial variable values. At step 33 a pedal based throttle limit Pedal_lim is calculated in accordance with the sensed throttle pedal position as invoked by the vehicle operator. Such Pedal_lim essentially follows the operator's actuation of the throttle pedal. The position transduced from the position sensor 26 ( FIG. 1 ) is thereby used to establish Pedal_lim at some finite value in terms of throttle area. Next, step 35 represents the inferential determination of the status of the cruise control system. If cruise control is not active, control passes to step 41 whereat the final throttle limit (LIM) is set to Pedal_lim, effectively providing throttle authority to the operator in accordance with the actuated throttle pedal position. An active cruise control system will result in step 35 passing control to step 37 whereat a rate increment value, Rate_up, is set to a value in accord with the current engine speed Ne and vehicle speed Nv operating point. The Ne/Nv ratio effects consideration of the current transmission speed ratio and resultant vehicle performance characteristics on setting an appropriate rate limit increment. Control passes to step 39 whereat Pedal_lim is compared to the requested cruise throttle area request CRZ_area_req. An additional dead band offset (K 1 ) is added to CRZ_area_req for hysteretic stability purposes. Where Pedal_lim is greater than CRZ_area_req, step 41 is executed to set LIM to Pedal_lim, effectively providing throttle authority to the operator in accordance with the actuated throttle pedal position. From step 41 , the routine executes step 49 which is executed prior to any exit of the routine to set LIM_old to the current limit LIM for use in subsequent control loops. If, however, Pedal_lim is not greater than CRZ_area_req, rate limiting is invoked as applied to throttle position changes beginning at step 43 .
[0041] At step 43 , CRZ_area_req is compared to the prior control loop final throttle limit LIM_old less a predetermined dead band offset (K 2 ). If the requested cruise throttle area exceeds the prior limit value then step 45 sets the final throttle limit LIM at a rate corresponding to the rate limit increment Rate_up. The final throttle limit LIM is established by adding the prior control loop final throttle limit LIM_old to the rate limit increment Rate_up. From step 45 , the routine executes step 49 to set LIM_old to the current limit LIM for use in subsequent control loops. If at step 43 the requested cruise throttle area does not exceed the prior control loop final throttle limit then step 47 sets the final throttle limit LIM in accord with the cruise throttle area request. The limit corresponding to the cruise throttle area request is established as CRZ_area_req plus a dead band offset (K 3 ). In effect, a cruise throttle area request not greater than the prior control loop final throttle limit indicates a decreasing throttle request at step 43 and provides throttle authority to the cruise throttle area request at step 47 . From step 47 , the routine executes step 49 to set LIM_old to the current limit LIM for use in subsequent control loops.
[0042] FIG. 6 illustrates various limit scenarios in accord with the adaptive cruise control related embodiment just described with respect to the flow diagram of FIG. 4 . In FIG. 6 , the line labeled 83 represents the cruise throttle area request, CRZ_area_req. The line labeled 85 represents the pedal based throttle limit, Pedal_lim and the line labeled 81 represents the final throttle area limit, LIM. Various time progressions of the throttle control of the present invention appear as alphabetic labels below the horizontal axis of the graph and will be referred to in the various illustrations herein below.
[0043] Beginning with the interval from time A to time B it can be seen that the cruise throttle area request 83 is substantially above the throttle pedal limit 85 but is increasing substantially at a first rate. This rate, however, is greater than the allowed rate by the limit control and hence the final limit 81 increases at a rate that is less than the requested rate. The cruise throttle area request levels off and the final limit continues to increase at the limited rate until it exceeds the request by the dead band offset whereupon the final limit levels off also. Since the cruise throttle area request is greater than the pedal based throttle limit, the cruise request has authority and the limit is set in accord therewith. An extreme rate of change in the cruise throttle area request is illustrated (time C). Such excessive changes might be consistent with a corruption in the integrity of the cruise throttle area request due, for example, to a hardware anomaly. However, the limit control of the present invention provides a final throttle rate limit 81 (interval C-D). The throttle responds to the excessive cruise throttle area request at the limited rate. At time D the cruise throttle area request returns to substantially its former value prior to the assumed corruption thereof. The final limit immediately tracks the request until it reaches the dead band offset therewith. At time E, the pedal based throttle limit 85 step increases significantly such as in response to the operator's request. Here, the throttle authority is with the pedal based throttle limit and the final limit 81 substantially tracks therewith (interval E-F). In the interim of interval E to F the cruise throttle area request 83 is seen increasing in substantial step wise fashion. But since it remains below the pedal based throttle limit it has substantially no effect in the final limit 81 which continues to be set in accord with the pedal based throttle limit. At time F when the pedal based throttle limit 81 is seen to return to substantially its former value, such as in response to the operator's request, the final limit 81 continues to track the pedal based throttle limit until it comes within the dead band of the now increased cruise throttle area request whereafter the final limit 81 is set in accord with the dead band offset of the substantially static cruise throttle area request 83 .
[0044] Turning now to FIG. 5 a routine representing program steps particularly related to the throttle control of the present invention as relates to power take-off control system effective to control engine speed substantially to a set engine speed. Step 51 represents steps executed for the purposes of initializing various registers and variables as in the previously described routines wherein certain of the steps may be executed upon power up only, or through the first interrupt only, for example to seed initial variable values. Step 53 establishes a power take-off engine speed request limit (PTO_Ne_req_lim). The limit is set in accord with the smaller of a limit calculated at a rate corresponding to the calibrated rate limit increment (K 1 ) or the power take-off engine speed request. The limit value is established by adding the prior control loop limit (PTO_Ne_req_lim_old) to the rate limit increment K 1 whereas the limit corresponding to the power take-off engine speed request is established as the request (PTO_Ne_req). Essentially, where the power take-off engine speed request is increasing, its increase rate is limited. But where the power take-off engine speed request is decreasing, the engine speed authority is given to the power take-off engine speed request and the limit tracks the request at its rate of decrease. Step 53 of the routine also sets PTO_Ne_req_lim_old to the current limit PTO_Ne_req_lim for use in subsequent control loops. At step 55 a pedal based throttle limit Pedal_lim is calculated in accordance with the sensed throttle pedal position as invoked by the vehicle operator. Such Pedal_lim essentially follows the operator's actuation of the throttle pedal. The position transduced from the position sensor 26 ( FIG. 1 ) is thereby used to establish Pedal_lim at some finite value in terms of throttle area.
[0045] Next, step 57 represents the determination of the status of the power take-off system. In the system architected as described, the various power take-off switch inputs are used in an inferentially based determination of whether power take-off control is active. If power take-off control is not active, control passes to step 65 whereat the final throttle limit LIM is set to Pedal_lim, effectively providing throttle authority to the operator in accordance with the actuated throttle pedal position. An active power take-off control system will result in step 57 passing control to step 59 whereat engine speed Ne is compared to the minimum of the power take-off engine speed request limit PTO_Ne_req_lim established at step 53 and the power take-off engine speed request PTO_Ne_req. Comparison to the minimum of these two variables provides protection against corruption of one of them. An additional dead band offset (K 2 ) is added to the minimum of PTO_Ne_req_lim and PTO_Ne_req for hysteretic stability purposes. Where Ne is not less than the minimum of PTO_Ne_req_lim and PTO_Ne_req, step 63 is executed to set LIM in accord with a limit calculated at a rate corresponding to a calibrated rate limit decrement (K 4 ) or Pedal_lim. The rate limit value is established by adding the prior control loop limit (LIM_old) to the rate limit decrement K 4 . This effectively provides throttle authority to the operator in accordance with the actuated throttle pedal position if it exceeds the prior loop throttle limit and otherwise continuing to rate limit the throttle reductions in accord with the preestablished rate. If, however, Ne is less than the minimum of PTO_Ne_req_lim and PTO_Ne_req, step 61 is executed to set LIM in accord with a limit calculated at a rate corresponding to a calibrated rate limit increment (K 3 ) or Pedal_lim. The rate limit value is established by adding the prior control loop limit (LIM_old) to the rate limit increment K 3 . This effectively provides throttle authority to the operator in accordance with the actuated throttle pedal position if it exceeds the prior loop throttle limit and otherwise continuing to rate limit the throttle increases in accord with the preestablished rate. Additionally, step 61 places an absolute cap on LIM of 100% throttle should either of Pedal_lim and the rate limit exceed 100%. Prior to exiting the routine, step 67 is executed to set LIM_old to the current limit LIM for use in subsequent control loops.
[0046] The various routines described are implemented at a minimum with the MAIN processor section within the TPSR block and applied to the desired throttle position signal which is acted upon by the ETC block in establishing the intake air valve position command signal. Preferably, it is envisioned that the routines are implemented in substantially redundant fashion in MCP processor section as shown in FIG. 36 by throttle limit block TLIM 129 as previously mentioned. TLIM 129 may provide a secondary review of the rationality of intake air valve position command signal provided by ETC 127 and if unacceptable take additional action such as setting diagnostic codes, providing alternative intake air valve position command signals or partially or fully disabling the particular system suspected responsible for the inconsistent results.
[0047] Certain preferred embodiments of the present invention have been described herein. Those skilled in the art will recognize various alternative implementations for practicing the invention within the scope of the following claims.
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A throttle limit control for an internal combustion engine throttle control is disclosed. Rate limiting is applied to prevent excessive rates of change in throttle actuation. Throttle pedal authority is continually maintained and throttle headroom is not compromised thereby. Application to various systems including conventional and adaptive cruise systems and power take-off systems is envisioned.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/900,265, filed Oct. 7, 2010, now U.S. Pat. No. 8,593,717 issued Nov. 26, 2010, which is a continuation of U.S. application Ser. No. 11/862,156, filed Sep. 26, 2007 (now U.S. Pat. No. 7,813,027), which is a continuation of U.S. application Ser. No. 11/448,243, filed Jun. 6, 2006; which is a continuation of U.S. application Ser. No. 11/126,494, filed May 10, 2005 (now U.S. Pat. No. 7,057,797); which is a continuation of U.S. application Ser. No. 10/638,124, filed Aug. 8, 2003 (now U.S. Pat. No. 6,891,656); which is a continuation of U.S. application Ser. No. 10/271,521, filed Oct. 15, 2002 (now U.S. Pat. No. 6,934,071); which is a continuation of U.S. application Ser. No. 09/882,755, filed Jun. 15, 2001 (now U.S. Pat. No. 6,466,357); which is a continuation of U.S. application Ser. No. 09/500,393, filed Feb. 8, 2000 (now U.S. Pat. No. 6,256,136); which is a continuation of U.S. application Ser. No. 09/145,314, filed Aug. 31, 1998 (now U.S. Pat. No. 6,057,958); which claims priority from U.S. provisional application Nos. 60/059,161, filed Sep. 17, 1997, and 60/065,133, filed Nov. 12, 1997. The disclosures of the prior applications are considered part of (and are incorporated by reference in) the disclosure of this application.
FIELD
[0002] The present invention relates to a system of controlling light beam pattern (“gobo”) shape in a pixilated gobo control system.
BACKGROUND
[0003] Commonly assigned patent application Ser. No. 08/854,353, the disclosure of which is herewith incorporated by reference, describes a stage lighting system which operates based on computer-provided commands to form special effects. One of those effects is control of the shape of a light pattern that is transmitted by the device. This control is carried out on a pixel-by-pixel basis, hence referred to in this specification as pixilated. Control is also carried out using an x-y controllable device. The preferred embodiment describes using a digital mirror device, but other x-y controllable devices such as a grating light valve, are also contemplated.
[0004] The computer controlled system includes a digital signal processor 106 which is used to create an image command. That image command controls the pixels of the x-y controllable device to shape the light that it is output from the device.
[0005] The system described in the above-referenced application allows unparalleled flexibility in selection of gobo shapes and movement. This opens an entirely new science of controlling gobos. The present inventors found that, unexpectedly, even more flexibility is obtained by a special control language for controlling those movements.
SUMMARY
[0006] The present disclosure defines a way of communicating with an x-y controllable device to form special electronic light pattern shapes. More specifically, the present application describes using a control language to communicate with an electronic gobo in order to reposition part or all of the image that is shaping the light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other aspects of the invention will now be described with reference to the attached drawings, in which:
[0008] FIG. 1 shows a block diagram of the basic system operating the embodiment;
[0009] FIG. 2 shows a basic flowchart of operation;
[0010] FIG. 3 shows a flowchart of forming a replicating circles type gobo;
[0011] FIG. 4A through 4G show respective interim results of carrying out the replicating circles operation;
[0012] FIG. 5 shows the result of two overlapping gobos rotating in opposite directions; and
[0013] FIGS. 6 ( 1 ) through 6 ( 8 ) show a z-axis flipping gobo.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] FIG. 1 shows a block diagram of the hardware used according to the preferred embodiment. As described above, this system uses a digital mirror device 100 , which has also been called a digital mirror device (“DMD”) and a digital light processor device (“DLP”). More generally, any system which allows controlling shape of light on a pixel basis, including a grating light valve, could be used as the light shaper. This light shaper forms the shape of light which is transmitted. FIG. 1 shows the light being transmitted as 102 , and shows the transmitted light. The information for the digital minor 100 is calculated by a digital signal processor 106 . Information is calculated based on local information stored in the lamp, e.g., in ROM 109 , and also in information which is received from the console 104 over the communication link.
[0015] The operation is commanded according to a format.
[0016] The preferred data format provides 4 bytes for each of color and gobo control information.
[0017] The most significant byte of gobo control data, (“dfGobo”) indicates the gobo type. Many different gobo types are possible. Once a type is defined, the gobo formed from that type is represented by a number. That type can be edited using a special gobo editor described herein. The gobo editor allows the information to be modified in new ways, and forms new kinds of images and effects.
[0018] The images which are used to form the gobos may have variable and/or moving parts. The operator can control certain aspects of these parts from the console via the gobo control information. The type of gobo controls the gobo editor to allow certain parameters to be edited.
[0019] The examples given below are only exemplary of the types of gobo shapes that can be controlled, and the controls that are possible when using those gobo shapes. Of course, other controls of other shapes are possible and predictable based on this disclosure.
[0020] A first embodiment is the control of an annulus, or “ring” gobo. The DMD 100 in FIG. 1 is shown with the ring gobo being formed on the DMD. The ring gobo is type 000A. When the gobo type 0A is enabled, the gobo editor 110 on the console 104 is enabled and the existing gobo encoders 120 , 122 , 124 , and 126 are used. The gobo editor 110 provides the operator with specialized control over the internal and the external diameters of the annulus, using separate controls in the gobo editor.
[0021] The gobo editor and control system also provides other capabilities, including the capability of timed moves between different edited parameters. For example, the ring forming the gobo could be controlled to be thicker. The operation could then effect a timed move between these “preset” ring thicknesses. Control like this cannot even be attempted with conventional fixtures.
[0022] Another embodiment is a composite gobo with moving parts. These parts can move though any path that are programmed in the gobo data itself. This is done in response to the variant fields in the gobo control record, again with timing. Multiple parts can be linked to a single control allowing almost unlimited effects.
[0023] Another embodiment of this system adapts the effect for an “eye” gobo, where the pupil of the eye changes its position (look left, look right) in response to the control.
[0024] Yet another example is a Polygon record which can be used for forming a triangle or some other polygonal shape.
[0025] The control can be likened to the slider control under a QuickTime movie window, which allows you to manually move to any point in the movie. However, our controls need not be restricted to timelines.
[0026] Even though such moving parts are used, scaling and rotation on the gobo is also possible.
[0027] The following type assignments are contemplated: [0028] 00-0F=FixedGobo (with no “moving parts”) [0029] 10-1F=SingleCntrl (with 1 “moving part”) [0030] 20-2F=DoubleCntrl (with 2 “moving parts”) [0031] 30-FF=undefined, reserved.
[0028] The remaining control record bytes for each type are defined as follows: TABLE-US-00001 Byte: total dfGobo2 dfGobo3 dfGobo4 #gobos/type memory FixedGobo: ID[23:16] ID[15:8] ID[7:0] 16M/type.sup. 256 M SingleCntrl: ID[15:8] ID[7:0] control#1 64 k/type .sup. 1 M DoubleCntrl: ID[7:0] control#2 control#1 256/type 4 k
[0029] As can be seen from this example, this use of the control record to carry control values does restrict the number of gobos which can be defined of that type, especially for the 2-control type.
[0030] Console Support:
[0031] The use of variant part gobos requires no modifications to existing console software for the ICON (7M) console. The Gobo editor in current ICON software already provides 4 separate encoders for each gobo. These translate directly to the values of the 4 bytes sent in the communications data packet as follows: TABLE-US-00002 Byte: dfGobo dfGobo2 dfGobo3 dfGobo4 Enc: TopRight MidRight BotRight BotLeft FixedGobo: ID[23:16] ID[15:8] ID[7:0] SingleCntrl: ID[15:8] ID[7:0] control#1 DoubleCntrl: ID[7:0] control#2 control#1
[0032] These values would be part of a preset gobo, which could be copied as the starting point.
[0033] Once these values are set, the third and fourth channels automatically become the inner/outer radius controls. Using two radii allows the annulus to be turned “inside out”.
[0034] Each control channel's data always has the same meaning within the console. The console treats these values as simply numbers that are passed on. The meanings of those numbers, as interpreted by the lamps change according to the value in dfGobo.
[0035] The lamp will always receives all 4 bytes of the gobo data in the same packet. Therefore, a “DoubleCntrl” gobo will always have the correct control values packed along with it.
[0036] Hence, the console needs no real modification. If a “soft” console is used, then name reassignments and/or key reassignments may be desirable.
[0037] Timing:
[0038] For each data packet, there is an associated “Time” for gobo response. This is conventionally taken as the time allotted to place the new gobo in the light gate. This delay has been caused by motor timing. In this system, variant gobo, the control is more dynamically used. If the non-variant parts of the gobo remain the same, then it is still the same gobo, only with control changes. Then, the time value is interpreted as the time allowed for the control change.
[0039] Since different gobo presets (in the console) can reference the same gobo, but with different control settings, this allows easily programmed timed moves between different annuli, etc.
[0040] Internal Workings:
[0041] When the gobo command data is extracted from the packet at the lamp, the dfGobo byte is inspected first, to see if either dfGobo3 or dfGobo4 are significant in selecting the image. In the case of the “Cntrl” variants, one or both of these bytes is masked out, and the resulting 32-bit number is used to search for a matching gobo image (by Gobo .sub.-1D) in the library stored in the lamp's ROM 109 .
[0042] If a matching image is found, and the image is not already in use, then the following steps are taken:
[0043] 1) The image data is copied into RAM, so that its fields may be modified by the control values. This step will be skipped if the image is currently active.
[0044] 2) The initial control values are then recovered from the data packet, and used to modify certain fields of the image data, according to the control records.
[0045] 3) The image is drawn on the display device, using the newly-modified fields in the image data.
[0046] If the image is already in use, then the RAM copy is not altered. Instead, a time-sliced task is set up to slew from the existing control values to those in the new data packet, in a time determined by the new data packet.
[0047] At each vertical retrace of the display, new control values are computed, and steps 2 (using the new control values) and 3 above are repeated, so that the image appears modified with time.
[0048] The Image Data Records:
[0049] All images stored in the lamp are in a variant record format:
[0050] Header:
[0051] Length 32 bits, offset to next gobo in list.
[0052] Gobo .sub.-1D 32 bits, serial number of gobo.
[0053] Gobo Records: TABLE-US-00003 Length 32 bits, offset to next record. Opcode 16 bits, type of object to be drawn. Data Variant part—data describing object. Length 32 bits, offset to next record. Opcode 16 bits, type of object to be drawn. Data Variant part—data describing object.
[0054] EndMarker 64 bits, all zeroes—indicates end of gobo data.
[0055] +Next gobo, or End Marker, indicating end of gobo list.
[0056] Gobos with controls are exactly the same, except that they contain control records, which describe how the control values are to affect the gobo data. Each control record contains the usual length and Opcode fields, and a field containing the control number (1 or 2).
[0057] These are followed by a list of “field modification” records. Each record contains information about the offset (from the start of the gobo data) of the field, the size (8, 16 or 32 bits) of the field, and how its value depends on the control value. TABLE-US-00004 Length 32 bits, offset to next record Opcode 16 bits=control_record (constant) CntrlNum 16 bits=1 or 2 (control number) /* field modification record #1 */ Address 16 bits, offset from start of gobo to affected field. Flags 16 bits, information about field (size, signed, etc) Scale 16 bits, scale factor applied to control before use ZPoint 16 bits, added to control value after scaling. /* field modification record #2 */ Address 16 bits, offset from start of gobo to affected field. Flags 16 bits, information about field (size, signed, etc) Scale 16 bits, scale factor applied to control before use ZPoint 16 bits, added to control value after scaling.
[0058] As can be seen, a single control can have almost unlimited effects on the gobo, since ANY values in the data can be modified in any way, and the number of field modification records is almost unlimited.
[0059] Note that since the control records are part of the gobo data itself, they can have intimate knowledge of the gobo structure. This makes the hard-coding of field offsets acceptable.
[0060] In cases where the power offered by this simple structure is not sufficient, a control record could be defined which contains code to be executed by the processor. This code would be passed parameters, such as the address of the gobo data, and the value of the control being adjusted.
[0061] Example Records.
[0062] The Annulus record has the following format: TABLE-US-00005 Length 32 bits Opcode 16 bits, =type_annulus Pad 16 bits, unused Centre_x 16 bits, x coordinate of centre Centre_y 16 bits, y coordinate of centre OuterRad 16 bits, outside radius (the radii get swapped when drawn if their values are in the wrong order) InnerRad 16 bits, inside radius
[0063] It can be seen from this that it is easy to “target” one of the radius parameters from a control record. Use of two control records, each with one of the radii as a target, would provide full control over the annulus shape.
[0064] Note that if the centre point coordinates are modified, the annulus will move around the display area, independent of any other drawing elements in the same gobo's data.
[0065] The Polygon record for a triangle has this format: TABLE-US-00006 Length 32 bits Opcode 16 bits, =type_polygon Pad 16 bits, vertex count=3 Centre_x 16 bits, x coordinate of vertex Centre_y 16 bits, y coordinate of vertex Centre_x 16 bits, x coordinate of vertex Centre_y 16 bits, y coordinate of vertex Centre_x 16 bits, x coordinate of vertex Centre_y 16 bits, y coordinate of vertex
[0066] It is easy to modify any of the vertex coordinates, producing distortion of the triangle.
[0067] The gobo data can contain commands to modify the drawing environment, by rotation, scaling, offset, and color control, the power of the control records is limitless.
Second Embodiment
[0068] This second embodiment provides further detail about implementation once the gobo information is received.
[0069] Gobo information is, at times, being continuously calculated by DSP 106 . The flowchart of FIG. 2 shows the handling operation that is carried out when new gobo information is received.
[0070] At step 200 , the system receives new gobo information. In the preferred embodiment, this is done by using a communications device 111 in the lamp 99 . The communications device is a mailbox which indicates when new mail is received. Hence, the new gobo information is received at step 200 by determining that new mail has been received.
[0071] At step 202 , the system copies the old gobo and switches pointers. The operation continues using the old gobo until the draw routine is called later on.
[0072] At step 204 , the new information is used to form a new gobo. The system uses a defined gobo (“dfGobo”) as discussed previously which has a defined matrix. The type dfGobo is used to read the contents from the memory 109 and thereby form a default image. That default image is formed in a matrix. For example, in the case of an annulus, a default size annulus can be formed at position 0,0 in the matrix. An example of forming filled balls is provided herein.
[0073] Step 206 represents calls to subroutines. The default gobo is in the matrix, but the power of this system is its ability to very easily change the characteristics of that default gobo. In this embodiment, the characteristics are changed by changing the characteristics of the matrix and hence, shifting that default gobo in different ways. The matrix operations, which are described in further detail herein, include scaling the gobo, rotation, iris, edge, strobe, and dimmer. Other matrix operations are possible. Each of these matrix operations takes the default gobo, and does something to it.
[0074] For example, scale changes the size of the default gobo rotation rotates the default gobo by a certain amount. Iris simulates an iris operation by choosing an area of interest, typically circular, and erasing everything outside that area of interest. This is very easily done in the matrix, since it simply defines a portion in the matrix where all black is written.
[0075] Edge effects carry out certain effects on the edge such as softening the edge. This determines a predetermined thickness, which is translated to a predetermined number of pixels, and carries out a predetermined operation on the number of pixels. For example, for a 50% edge softening, every other pixel can be turned off. The strobe is in effect that allows all pixels to be turned on and off at a predetermined frequency, i.e., 3 to 10 times a second. The dimmer allows the image to be made dimmer by turning off some of the pixels at predetermined times.
[0076] The replicate command forms another default gobo, to allow two different gobos to be handled by the same record. This will be shown with reference to the exemplary third embodiment showing balls. Each of those gobos is then handled as the same unit and the entirety of the gobos can be, for example, rotated. The result of step 206 and all of these subroutines that are called is that the matrix includes information about the bits to be mapped to the digital mirror 100 .
[0077] At step 208 , the system then obtains the color of the gobos from the control record discussed previously. This gobo color is used to set the appropriate color changing circuitry 113 and 115 in the lamp 99 . Note that the color changing circuitry is shown both before and after the digital mirror 100 . It should be understood that either of those color changing circuits could be used by itself.
[0078] At step 210 , the system calls the draw routine in which the matrix is mapped to the digital mirror. This is done in different ways depending on the number of images being used. Step 212 shows the draw routine for a single image being used as the gobo. In that case, the old gobo, now copied as shown in step 202 , is faded out while the new gobo newly calculated is faded in. Pointers are again changed so that the system points to the new gobo. Hence, this has the effect of automatically fading out the old gobo and fading in the new gobo.
[0079] Step 214 schematically shows the draw routine for a system with multiple images for an iris. In that system, one of the gobos is given priority over the other. If one is brighter than the other, then that one is automatically given priority. The one with priority 2 , the lower priority one, is written first. Then the higher priority gobo is written. Finally, the iris is written which is essentially drawing black around the edges of the screen defined by the iris. Note that unlike a conventional iris, this iris can take on many different shapes. The iris can take on not just a circular shape, but also an elliptical shape, a rectangular shape, or a polygonal shape. In addition, the iris can rotate when it is non-circular so that for the example of a square iris, the edges of the square can actually rotate.
[0080] Returning to step 206 , in the case of a replicate, there are multiple gobos in the matrix. This allows the option of spinning the entire matrix, shown as spin matrix.
[0081] An example will now be described with reference to the case of repeating circles. At step 200 , the new gobo information is received indicating a circle. This is followed by the other steps of 202 where the old gobo is copied, and 204 where the new gobo is formed. The specific operation forms a new gobo at step 300 by creating a circle of size diameter equals 1000 pixels at origin 00. This default circle is automatically created. FIG. 4A shows the default gobo which is created, a default size circle at 00. It is assumed for purposes of this operation that all of the circles will be the same size.
[0082] At step 302 , the circle is scaled by multiplying the entire circle by an appropriate scaling factor. Here, for simplicity, we are assuming a scaling factor of 50% to create a smaller circle. The result is shown in FIG. 4B . A gobo half the size of the gobo of FIG. 4A is still at the origin. This is actually the scale of the subroutine as shown in the right portion of step 302 . Next, since there will be four repeated gobos in this example, a four-loop is formed to form each of the gobos at step 304 . Each of the gobos is shifted in position by calling the matrix operator shift. In this example, the gobo is shifted to a quadrant to the upper right of the origin. This position is referred to as n over 4 in the FIG. 3 flowchart and results in the gobo being shifted to the center portion of the top right quadrant as shown in FIG. 4C . This is again easily accomplished within the matrix by moving the appropriate values. At step 308 , the matrix is spun by 90 degrees in order to put the gobo in the next quadrant as shown in FIG. 4D in preparation for the new gobo being formed into the same quadrant. Now the system is ready for the next gobo, thereby calling the replicate command which quite easily creates another default gobo circle and scales it. The four-loop is then continued at step 312 .
[0083] The replicate process is shown in FIG. 4E where a new gobo 402 is formed in addition to the existing gobo 400 . The system then passes again through the four-loop, with the results being shown in the following figures. In FIG. 4F , the new gobo 402 is again moved to the upper right quadrant (step 306 ). In FIG. 4G , the matrix is again rotated to leave room for a new gobo in the upper right quadrant. This continues until the end of the four-loop. Hence, this allows each of the gobos to be formed.
[0084] Since all of this is done in matrix operation, it is easily programmable into the digital signal processor. While the above has given the example of a circle, it should be understood that this scaling and moving operation can be carried out for anything. The polygons, circles, annulus, and everything else is easily scaled.
[0085] The same operation can be carried out with the multiple parameter gobos. For example, for the case of a ring, the variable takes the form annulus (inner R, outer R, x and y). This defines the annulus and turns of the inner radius, the outer radius, and x and y offsets from the origin. Again, as shown in step 3, the annulus is first written into the matrix as a default size, and then appropriately scaled and shifted. In terms of the previously described control, the ring gobo has two controls: control 1 and control 2 defined the inner and outer radius.
[0086] Each of these operations is also automatically carried out by the command repeat count which allows easily forming the multiple position gobo of FIGS. 4A-4G . The variable auto spin defines a continuous spin operation. The spin operation commands the digital signal processor to continuously spin the entire matrix by a certain amount each time.
[0087] One particularly interesting feature available from the digital mirror device is the ability to use multiple gobos which can operate totally separately from one another raises the ability to have different gobos spinning in different directions. When the gobos overlap, the processor can also calculate relative brightness of the two gobos. In addition, one gobo can be brighter than the other. This raises the possibility of a system such as shown in FIG. 5 . Two gobos are shown spinning in opposite directions: the circle gobo 500 is spinning the counterclockwise direction, while the half moon gobo 502 is spinning in the clockwise direction. At the overlap, the half moon gobo which is brighter than the circle gobo, is visible over the circle gobo. Such effects were simply not possible with previous systems. Any matrix operation is possible, and only a few of those matrix operations have been described herein.
[0088] A final matrix operation to be described is the perspective transformation. This defines rotation of the gobo in the Z axis and hence allows adding depth and perspective to the gobo. For each gobo for which rotation is desired, a calculation is preferably made in advance as to what the gobo will look like during the Z axis transformation. For example, when the gobo is flipping in the Z axis, the top goes back and looks smaller while the front comes forward and looks larger. FIGS. 6 ( 1 )- 6 ( 8 ) show the varying stages of the gobo flipping. In FIG. 6 ( 8 ), the gobo has its edge toward the user. This is shown in FIG. 6 ( 8 ) as a very thin line, e.g., three pixels wide, although the gobo could be zero thickness at this point. Automatic algorithms are available for such Z axis transformation, or alternatively a specific Z axis transformation can be drawn and digitized automatically to enable a custom look.
[0089] Although only a few embodiments have been described in detail above, other embodiments are contemplated by the inventor and are intended to be encompassed within the following claims. In addition, other modifications are contemplated and are also intended to be covered.
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A special record format used for commanding light pattern shapes and addressable light pattern shape generator. The command format includes a first part which commands a specified gobo and second parts which command the characteristics of that hobo. The gobo is formed by making a default gobo based on the type and modifying that default gobo to fit the characteristics.
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TECHNICAL FIELD
This invention relates to a process for producing superabsorbent articles in the form of soft, nonwoven fibrous webs. The nonwoven web material can be used per se or can be combined with other fibrous materials to form composites having a wide variety of applications, including diapers, sanitary napkins, incontinence products, towels, tissues, and other products for the absorption of significant quantities of fluids including body exudates and aqueous compositions of all kinds.
BACKGROUND OF THE INVENTION
The web formation process is critical in the production of all nonwoven articles. Webs are produced with a dominant fiber orientation in a known manner by textile machines such as cards or garnetts. It is also known to form webs wherein the fibers have a random arrangement by laying down on a moving wire fibers carried by a stream of an inert gas such as air. Typical processes of the latter type include the mixing of melt-blown fibers by high velocity gas streams from separate sources, as in U.S. Pat. Nos. 3,016,599, 3,502,763, 4,100,324 and 4,263,241. Other patents which use gas streams in web formation include U.S. Pat. Nos. 3,670,731, 4,235,237, 2,988,469, 4,102,963, 4,375,447, 3,755,028, 3,010,161, 2,500,282, 2,411,660 and the melt-blown fiber processes disclosed in U.S. Pat. Nos. 3,442,633, 3,497,337, 3,357,808 and 4,604,313. A wide variety of fiber types are disclosed in the foregoing patents, including natural and synthetic fibers and fibers formed from water-insoluble hydrogels including maleic anhydride copolymer gels such as disclosed in U.S. Pat. Nos. 3,901,236 and 4,610,678.
The higher the absorbency of a fiber the more difficult it is to form webs of the material having the requisite softness, flexibility and density particularly when the precursor polymer used to prepare the fibers is in solution. During the web formation process the inherent hygroscopicity of the fibers may cause the fibers to pick up water from the environment with the consequence that if the fibers are over-dried during the process, voids will form in the web and the web will crack. On the other hand, if the fibers are over-wet the web will become brittle during a subsequent curing operation. The resulting web in both cases will have poor integrity and lack the density, softness and flexibility desired.
SUMMARY OF THE INVENTION
A process has now been found which combines fiber and web formation in such manner that superabsorbent nonwoven webs can be produced, batch-wise but preferably continuously, wherein conditions are controlled to provide uniform density (desirably of about 30-200 g/m 2 ), integral but random fiber distribution, and the flexibility and softness important for use of the webs in water absorbent personal care products. The superabsorbency of the webs is demonstrated by their ability to absorb many times their weight of water and aqueous solutions, on the order of 40 to 1000 grams of water or aqueous solution per gram of web material under free swelling conditions and to retain similarly large quantities of aqueous fluids under pressure. "water" and "aqueous fluids" is herein intended to mean and include not only water per se but also electrolyte solutions, body fluids and aqueous solutions of all kinds.
In one aspect of the invention, nonwoven fibrous webs are produced from an aqueous solution of a fiber-forming polymer composition which initially is water soluble but becomes water insoluble and superabsorbent upon curing, wherein the polymer solution is formed into filaments, the filaments are contacted with a primary air stream having a velocity effective to attenuate the filaments, the attenuated filaments are contacted in a fiber-forming zone with a secondary air stream having a velocity effective to further attenuate and to fragment the filaments into fibers and to transport the fibers to a web-forming zone, the fibers are collected in reticulated web form in the web-forming zone, and the web is cured. Each air stream also evaporates water from the filaments and fibers (the secondary air stream more so than the primary air stream), the fibers thereby being dried to the extent that they will collect and cure to a soft web without substantially flowing or sticking together.
In another aspect, nonwoven web-producing apparatus is provided, comprising the combination of means for forming an aqueous polymer solution into filaments, first air supply means positioned to direct an air stream upon and to partially attenuate and dry the filaments, a housing having opposing inlet and outlet means, second air supply means positioned to direct an air stream upon the filaments for further attenuation and for fragmentation thereof, and to further dry and to carry the filaments through the inlet and outlet of the housing, a foraminous surface at the outlet of the housing for collecting the fragments in web form, suction means adjacent to the foraminous surface to entrain the fragments on the surface, and means for curing the web on the foraminous surface.
Other aspects of the invention include a nonwoven web-producing process wherein the polymer composition from which the fibers of the web are produced is a carboxylic polymer cross-linked by hydroxyl or heterocyclic carbonate functionality, and the nonwoven web produced by the process.
These and other aspects, features and advantages of the invention will be apparent from the drawings and specification which follow.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of apparatus useful in the process of the invention and includes identification of the major steps of the process;
FIG. 2 is a vertical section of one embodiment of an extrusion die useful in the filament formation step of the process; and
FIG. 3 is a vertical section along the line 3--3 of FIG. 2 showing other structure of the extrusion die of FIG. 2.
DETAILED DESCRIPTION
With reference to FIG. 1 of the drawings, in the filament forming step of the invention a hydrophilic polymer solution supplied from one or more feed tanks, such as steam-heated and motor (M)-agitated polymer feed tanks 10 and 12, is pumped by pump 14 having a flow control (F) via line 16 to filament forming means such as an extrusion device 18. The extrusion device may have any suitable design including one or more nozzles, spinnerets or die openings. FIGS. 2 and 3 illustrate one embodiment of extrusion device in the form of a die (described in detail below). The viscosity of the polymer solution is regulated by the solids content of the polymer composition feed stock and temperature thereof for an efficient rate of extrusion. Heating the polymer feed up to about 200° F. as necessary is accomplished by steam jackets or other means. For example, at a solids concentration of about 25-60%, preferably about 35-55% and an extrusion device comprising a bank of nozzles with openings of 0.028 inch diameter, a suitable extrusion rate is about 2.5 grams per minute per nozzle at room temperature (ca.70° F.). If the extrusion device includes a die having, for example, a length of about 3-10 inches and 6-12 holes per inch, the holes being evenly spaced and 0.020 inches in diameter, a suitable extrusion rate is about 0.5 to 5 grams per minute per hole at room temperature. Of course, the extrusion rate will also depend upon the type and character of the polymer composition, particularly its viscosity.
While hydrophilic thermosetting and thermoplastic polymer compositions of all types may be used in the process, such as the polymer types described in the patents cited above (the disclosures of which are incorporated herein by reference), the process has particular applicability to filament and web formation from a polymer composition comprising a blend of (1) a copolymer of at least one alpha, beta-unsaturated carboxylic monomer and at least one monomer copolymerizable therewith, and (2) a cross-linking agent having crosslinking functionality comprising hydroxyl or heterocyclic carbonate groups. More particularly, the polymer composition is a blend of a copolymer of the foregoing type having about 20-80 weight percent pendant carboxylic acid groups and about 80-20 weight percent pendant carboxylate groups, and a suitable hydroxyl or O-heterocyclic carbonate-containing crosslinker.
The copolymer of the polymer composition may contain about 25-75 mole percent recurring units of at least one alpha, beta-unsaturated monomer bearing at least one pendant unit selected from carboxylic acid units and derivatives of carboxylic acid units, and about 75-25 mole percent recurring units of at least one monomer copolymerizable therewith, wherein about 20-80 mole percent of the total pendant units introduced through the recurring alpha, betaunsaturated monomer units are carboxylic units or which are converted into carboxylic acid units, and wherein about 80-20% of the total pendant units are carboxylate salt units or which are converted into carboxylate salt units. Preferably, the copolymer will contain about 35-65 total mole percent of recurring units of at least one alpha, betaunsaturated monomer and about 65-35 total mole percent of at least one copolymerizable monomer. More preferably, the comonomers of the copolymer will be present in equimolar proportions.
Suitable hydroxyl-containing crosslinking units include one or more compounds having at least two hydroxyl groups, such as alkylene glycols of 2-10 carbon atoms and ethers thereof, cyclic alkylene glycols, bisphenol A, hydroxy alkylene derivatives of bisphenol A, hydroquinone, phloroglucinol, hydroxy alkylene derivatives of diphenols, glycerol, erythritol, pentaerythritol, monosaccharides and other compounds specified hereinafter.
Suitable, alpha, beta-unsaturated monomers are those bearing at least one pendant carboxylic acid unit or derivative of a carboxylic acid unit. Derivatives or carboxylic acid units include carboxylic acid salt groups, carboxylic acid amide groups, carboxylic acid imide groups, carboxylic acid anhydride groups and carboxylic acid ester groups.
Typical alpha, beta-unsaturated monomers useful in the invention include maleic acid, crotonic acid, fumaric acid, mesaconic acid, the sodium salt of maleic acid, the sodium salt of 2-methyl, 2-butene dicarboxylic acid, the sodium salt of itaconic acid, maleamic acid, maleamide; N-phenyl maleimide, maleimide, maleic anhydride, fumaric anhydride, itaconic anhydride, citraconic anhydride, methyl itaconic anhydride, ethyl maleic anhydride diethylmaleate, methylmaleate, and the like, and any mixtures thereof.
Any suitable copolymerizable comonomer can be employed. Suitable copolymerizable comonomers include ethylene, propylene, isobutylene, C 1 to C 4 alkyl (meth)acrylates, vinyl acetate, methyl vinyl ether, isobutyl vinyl ether, and styrenic compounds having the formula: ##STR1## wherein R represents or an alkyl group having from 1 to 6 carbon atoms and wherein the benzene ring may be substituted with low molecular weight alkyl or hydroxy groups.
Typical C 1 to C 4 alkyl acrylates include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, and the like, and any mixtures thereof. Suitable C 1 to C 4 alkyl methacrylates include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propylmethacrylate, n-butyl methacrylate, and the like, and any mixtures thereof. Suitable styrenic compounds include styrene, alpha-methylstyrene, p-methylstyrene, t-butyl styrene, and the like, and any mixtures thereof.
The pendant units on the alpha, beta-unsaturated monomer, will determine what, if any, additional reactions must be carried out to obtain a copolymer having the requisite pendant units necessary to produce water-absorbing polymer compositions useful in the invention having about 20-80 percent pendant groups such as carboxylic acid units and about 80 to about 20 percent pendant carboxylate salt units. Preferably, both units are present in an amount of from about 30 to about 70 percent.
In general, if the alpha, beta-unsaturated monomer bears only carboxylic acid amide, carboxylic acid imide, carboxylic acid anhydride, carboxylic acid ester groups, or mixtures thereof, it will be necessary to convert at least a portion of such carboxylic acid derivative groups to carboxylic acid groups by, for example, a hydrolysis reaction. If the alpha, beta-unsaturated monomer bears only carboxylic acid salt groups, acidification to form carboxylic acid group will be necessary.
Similarly, the final copolymer must contain about 80-20 percent pendant carboxylate salt units. Accordingly, it may be necessary to carry out a neutralization reaction Neutralization of carboxylic acid groups with a strong organic or inorganic base such as NaOH, KOH, ammonia, ammonia-in-water solution, or organic amines will result in the formation of carboxylate salt units, preferably carboxylate metal salt units.
The sequence and the number of reactions (hydrolysis, acidification, neutralization, etc.) carried out to obtain the desired functionality attached to the copolymer backbone are not critical. Any number and sequence resulting in a final copolymer which possess about 20-80 percent pendant carboxylic acid units and about 80-20 percent pendant carboxylate salt units is suitable.
One copolymer particularly suitable for use in forming superabsorbent webs in accordance with the invention is a copolymer of maleic anhydride and isobutylene. Another is maleic anhydride and styrene. Suitable copolymers will have peak molecular weights of from about 5,000 to about 500,000 or more. The copolymers of maleic anhydride and isobutylene and/or styrene can be prepared using any suitable conventional methods. Maleic anhydride/isobutylene copolymers are also commercially available from Kuraray Isoprene Chemical Company, Ltd., Tokyo, Japan, under the trademark ISOBAM. ISOBAM copolymers are available in several grades which are differentiated by viscosity molecular weight: ISOBAM-10, 160,000 to 170,000; ISOBAM-06, 80,000 to 90,000; ISOBAM-04, 55,000 to 65,000; and ISOBAM-600, 6,000 to 10,000.
To produce water-absorbing polymer compositions useful in the invention, at least one copolymer as described about and at least one crosslinking compound bearing at least two hydroxyl or heterocyclic carbonate groups are blended such that the waterabsorbing composition contains in weight percent about 80-99.5 total copolymer and about 0.5-20 total crosslinking compound. Preferably, the composition will contain about 90-99 weight percent total copolymer and about 1-10 weight percent total crosslinking agent.
Any suitable organic compound bearing at least two hydroxyl or heterocyclic carbonate groups and having a relatively low molecular weight, less than 1,000, can be employed as a crosslinking agent for the copolymers.
Suitable crosslinking compounds include ethylene carbonate, propylene carbonate, 1-2 butylene carbonate, 2-3 butylene carbonate, phenyl ethylene carbonate, ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butane diol, 2-methyl-1, 3-propane diol, neopentyl glycol, 1,5-pentane diol, diethylene glycol, dipropylene glycol, 1,4-cyclohexane dimethanol, Bisphenol A, 1,4-bis-(beta-hydroxyethoxy) bisphenol, hydroquinone, phlorogl ucinol, glycerol, erythritol, pentaerythritol, meso-erythritol, 1,7-dihydroxysedoheptulose, sucrose, natural monosaccharides, and the like, including any mixtures thereof.
In the filament forming step (again, with reference to FIG. 1), the polymer filament 20 is contacted with a primary air stream directed generally vertically from nozzles, openings in horizontally positioned tubes or other means as it leaves the extruder 18. The air is supplied by a compressor blower (operating up to about 25 psi) or other suitable source. The velocity of the air stream is selected to partially dry and attenuate the filaments to a diameter sufficiently small such that the filaments will be further attenuated and will fragment easily when contacted with a secondary air stream from nozzle 22 supplied from a blower 24 through a chamber 26. Blower 24 may be provided with a suitable controller (C) and flow indicator (F). A primary air stream velocity (measured 6 inches from the air exits) of at least about 500 feet per minute (fpm), e.g., about 500-8,000 fpm, will be effective. The secondary air temperature in tunnel 34 may be regulated by steam flow in line 28 to a heat exchanger 30 in chamber 26. A conventional temperature sensor (T) and controller (C) regulates the temperature through a suitable control valve and control valves actuator as shown. Filaments 20 will have diameters of about 5-20 microns as a result of the entrainment and attenuation by the primary air stream.
When contacted by the high velocity secondary air stream from nozzle 22, flowing at a velocity of at least about 3,000 feet per minute, e.g., about 3,000 to 10,000 feet per minute or greater, the filaments 20 are further attentuated and dried, and are fragmented into fiber pieces 32 which are carried by the secondary air and vaporized water through the housing or tunnel 34 having an inlet adjacent the nozzle 22 and an opposing outlet. The fibers then deposit on a foraminous collector surface such as a screen 36 positioned in the outlet of the tunnel. Screen 36 preferably is mounted or positioned at an angle to the longitudinal axis of tunnel 34, eg., about 45°. The temperature and humidity in the tunnel 34 are sensed and regulated such that the water content of fragments 32 as they collect on screen 36 is about 10-15 percent by weight. If the fiber fragments are over-dried at this point the resulting web will contain voids and subsequently crack during the curing step. If the fibers are too moist the web will become brittle during the subsequent curing. The secondary air stream in addition to fragmenting and drying the fibers, augments the attenuation of the fibers to the desired 5-20 micron diameter range.
Tunnel 34 is dimensioned to attain the proper moisture content in the fibers as they collect on screen 36. A tunnel housing about 12 feet long and having interior dimensions of about 3 feet by 3 feet is suitable but other dimensions will be effective depending upon the water content of the polymer composition as it is formed into filaments, the hydroscopicity of the polymer composition, and the extent to which the polymer composition is neutralized and crosslinked. Passage of the fibers through the tunnel as well as temperature and humidity control is facilitated by lining the tunnel with suitably surfaced insulating material, such as glass fiber batting surfaced with a water impervious film. While nozzle 22 and tunnel 34 are shown horizontally positioned in FIG. 1, vertical or other positioning may also be practiced.
Collection of the fiber fragments 34 on the screen 36 is facilitated by a suction generated by a blower 40 which pulls secondary air from tunnel 34 through an exhaust chamber 42. The suction also minimizes condensation of water on the interior walls of tunnel 34. The differential pressure of the suction generated by blower 40 is regulated by a controller (C) and measured by a pressure sensor (P) across the screen 36. The suctioned air is exhausted through a stack 41 and thereby also creates a pressure differential to hold the web in place on the screen 36 during initial passage into the oven 38.
Although screen 36 may comprise a fixed surface or a rotating drum separate from the tunnel 34, preferably screen 36 is a foraminous wire or wire mesh belt as shown, which moves continuously through a curing oven 38. Moisture sensors 44 having a readout M determine whether the fibrous material on the wire has the requisite moisture content as it enters the oven. Typically, the moisture should be less than 20% by weight as the material enters the oven, to prevent the fibers from flowing and sticking together, thereby losing fiber integrity. The fiber fragments now collected on the wire in web form are maintained on the wire during passage through the oven by air pressure against one side of the wire and suction from the other side generated by air cycled by a blower 46 from a suction conduit 48. The air is transported via a supply conduit 49 to a distribution region 50 subdivided into chambers or manifolds (not shown) positioned on one side of each of the vertical wires shown in FIG. 1. Air thus suctioned through one face of the wire is collected in an exhaust region 51 adjacent the opposing face of the wire to complete the air flow cycle. A heater 52 desirably is mounted upstream of blower 46 to heat the air stream as required for curing of the web. Suitable temperature controls (T,C) are provided to relate air temperature in the oven to speed of the wire and other parameters for efficient cure. The air pressure across wire 36 is measured by a sensor 54. Any design of curing oven, and air supply and exhaust system of the curing oven, suitable for obtaining efficient cure can be used. One such design is the oven and air distribution system commercially available from Honeycomb Systems, Inc., of Biddeford, Me.
An oven temperature of about 250° C. for about 5 minutes residence time or about 270° C. for about 2.5 minutes residence time provides good cure but lower temperatures and longer residence times are also suitable, such as about 210° C. for about 20 minutes. Higher temperatures can be used with concomitantly lower residence times provided the webs do not discolor. Generally, the oven temperature range may be about 150°-275° C. for residence times of about 35-0.5 minutes.
Upon emerging from the curing oven, product web 56 desirably is compacted by any suitable means such as nip rolls 58 and 60, and is transported to a take-up station 62 where it is wound on an idler spool 64 driven by spool 66. A tension controller (Y) regulates take-up tension in a known manner. If desired, embossing rolls may be used for the compaction to improve the integrity and appearance of the web by decreasing the visibility of small dis-continuities in the web.
FIGS. 2 and 3 illustrate one embodiment of a die suitable in forming the filaments in extrusion device 18. With reference thereto, a die head comprises a die head cover 68, one or more entry conduits 69, and a chamber 70 defining a manifold for entry of polymer syrup through channels 72 to nozzle feed chamber 74. The nozzle chamber is defined by tip body 76 and communicates with die holes 78. Filaments 80 are thus extruded and entrained by primary air streams 82 and 83 injected from openings in supply tubes 84 and 86. Suitable air supply tubes may be about 10 inches long and have 12 holes per inch wherein the hole diameter is 0.020 inch. The velocity and angles of impingement of air streams 82 and 83 upon filament 80 are selected relative to the viscosity of the polymer syrup and the location of the secondary air stream such that filaments 80 will be entrained and attenuated to the desired diameter range A suitable angle of impingement is 20 degrees. An air knife may be used in place of tubes 84 and 86, if desired.
Thus by practice by the process of the invention, superabsorbent webs of uniform density and having the requisite softness and flexibility are produced continuously and efficiently. The resulting web is dry to the touch and can be conveniently incorporated into various product forms in accordance with well-known procedures.
The following examples will serve, in conjunction with FIGS. 1-3, as further illustration of the invention.
EXAMPLE 1
A polymer syrup is prepared, comprising a 40% polymer solids solution of a maleic anhydride/isobutylene copolymer having a viscosity average molecular weight of about 160,000-170,000 and which is 50% neutralized with sodium hydroxide and crosslinked with 7 phr of propylene carbonate per (7 parts by weight of propylene carbonate per 100 parts by weight of copolymer).
A continuous web is produced by blowing fibers fragmented from filaments extruded from the polymer syrup through a die (such as die 18 of FIGS. 2 and 3) using primary air and secondary air as described hereinabove, to a web forming screen 36 comprising a wire mesh belt which travels through a curing oven 38. The polymer feed pump rate (Nichol-Zenith Pump, Model BLB-5456-30 cc/rev.) is set at 3 rpm, for extrusion of polymer at 100 gm/minute or at 2.6 gm/minute/hole in the die. The belt speed is set at 2.5 feet per minute. The relative polymer feed and wire speed are matched to give the desired web density. The required oven temperature is then set to completely cure the web in the residence time of the web in the heated zone of the curing oven. For an oven 63 feet long and a belt of 2.5 fpm, the cure time is 25 minutes. For this residence time, 195° C. is a suitable oven temperature. Once the polymer is flowing freely through the die, the belt is moving, and the proper oven temperature is reached, the primary air is turned on to reach a velocity of about 8000 fpm through the holes in the air tubes 84 and 86 of FIG. 1. Then, the secondary air is turned on to at least 7000 fpm for this feed rate and the air is heated to 125° C. The temperature of the secondary air is adjusted in chamber 26 to dry the web as it is formed to 10-15 wt. % moisture. The secondary and primary air are removed in the oven 38 through the belt and exhausted to the outside by exhaust blower 40 and suction box 42 behind the belt. One inch of water pressure drop across the web and belt is sufficient to exhaust the air and deposit the fibers in web form on the belt. The exhaust fan speed is increased until the pressure drop is achieved. The web travels through the oven on the moving belt and is removed at the exit where it can be embossed or simply rolled up. A web produced as described has a density of 105 g/m 2 , absorbs 40.2 g/g of 0.9% brine solution and retains 26.3 g/g of the brine solution under a pressure of 0.5 psi. The water-swelled web is dry to the touch.
EXAMPLE 2
Substantially as described in Example 1 but using a polymer formulation differing from that of Example 1 by substitution of pentaerythritol and butanediol for propylene carbonate in amounts of 8 phr and 2 phr, respectively, and increasing the belt speed to 2.8 fpm, a fibrous web is produced. The cure residence time is 22.5 minutes. The oven temperature for this formulation and residence time is 175° C. and the secondary air temperature is 100° C. The collector pressure drop on the belt is increased to 2.0 inches of water to draw the fibers to the belt more evenly. The web produced has a density of 83 g/m 2 , absorbs 48.8 g/g of a 0.9% brine solution and retains 28.9 g/g of the brine solution under a pressure of 0.5 psi. The solubility of the polymer is 14.6%.
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Superabsorbent articles in the form of soft, nonwoven fibrous webs are produced from aqueous fiber-forming polymer solutions by forming the polymer into water soluble filaments, contacting the filaments with a primary air stream having a velocity effective to attenuate and to partially dry the filaments, contacting the attenuated filaments with a secondary air stream having a velocity effective to fragment the filaments into fibers and to transport the fibers to a web-forming zone while also further attenuating and drying the fibers, collecting the fibers in reticulated web-form in the web-forming zone and curing the web to a water insoluble state. The temperature and air stream velocities are controlled with respect to ambient humidity and water content of the fiber during the fiber and web formation such that the fibers are collected without sticking. Collection is preferably on a wire belt followed by transport through a curing oven to compacting rolls and web take-up.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of prior U.S. application Ser. No. 13/364,877, filed Feb. 2, 2012, the disclosure of which is incorporated herein by reference in its entirety. The parent application claims priority to U.S. Provisional Application No. 61/439,392, filed Feb. 4, 2011, the disclosure of which is incorporated herein by reference in its entirety.
DESCRIPTION
This invention relates to low molecular weight phosphorus-containing polyacrylic acids, aqueous solutions comprising same, processes for production thereof and also use thereof as dispersants.
Dispersants, especially polyacrylic acids, are widely used in technical operations wherein a solid material is converted into a pumpable dispersion. To ensure wide industrial use, these dispersions, which are also known as slurries, have to have not only good pumpability but also stability in storage (minimal aging) coupled with high solids content. It is desirable for the latter to be raised as high as possible, owing to the high energy and transportation costs. A typical example is the use of aqueous calcium carbonate slurries in the production of graphics papers. While good flow properties on the part of the slurries substantially ensure processability in paper production and/or paper coating, the fineness of the dispersed solids determines the optical properties of the paper produced therefrom, such as the opacity for example. A lower particle size for the same solids content of the slurry results in a higher opacity for the paper produced therefrom. The particle size here is decisively influenced not only by the input of mechanical energy during the wet grinding of the pigment, but also through the choice of dispersant used.
It is known that low molecular weight polyacrylic acids produced by free-radical polymerization have good dispersing properties. The weight average molecular weight (Mw) of these polymers should be <50 000 for good performance. Polyacrylic acids with Mw <10 000 are often particularly effective. To produce low molecular weight polyacrylic acids, chain transfer agents are added as molecular weight regulators during the free-radical polymerization of acrylic acid. These regulators have to be adapted to the polymerization initiator and also to the polymerization process. Examples of known initiators are organic and inorganic per compounds, such as peroxodisulfates, peroxides, hydroperoxides and peresters, azo compounds such as 2,2′-azobisisobutyronitrile and redox systems with organic and inorganic components. The regulators used are frequently inorganic sulfur compounds such as hydrogensulfites, disulfites and dithionites, organic sulfides, sulfoxides, sulfones and mercapto compounds such as mercaptoethanol, mercaptoacetic acid and also inorganic phosphorus compounds such as hypophosphorous acid (phosphinic acid) and its salts (e.g., sodium hypophosphite).
EP-A 405 818 discloses a process for forming polymers from monoethylenically unsaturated monocarboxylic acids and optionally further monomers using sodium persulfate as initiator in the presence of hypophosphite as chain transfer agent, wherein an alkaline neutralizer is present during the polymerization in an amount sufficient to neutralize at least 20% of the acidic groups. The low molecular weight polymers obtained comprise at least 80% of the phosphorus from the hypophosphite. At least 70% of the phosphorus is said to end up within the polymer chain, as dialkyl phosphinate. The polymers thus obtained are used inter alia as laundry detergent additives, dispersants for clay slurries or scale inhibitors for water treatment.
In the exemplary embodiments, acrylic acid is polymerized in water in the presence of hypophosphite as chain transfer agent and sodium persulfate as initiator using the feed method wherein aqueous sodium hydroxide solution is added during the polymerization as a further continuous feed. This gives an aqueous polyacrylic acid having a weight average molecular weight M w of 2700 g/mol, which comprises 72% of the phosphorus in sodium phosphite as dialkyl phosphinate, 18% as monoalkyl phosphinate and 10% as inorganic salts. A comparative example dispenses with the aqueous sodium hydroxide feed and neutralizes with sodium hydroxide solution only after the polymerization has ended. The product obtained here is an aqueous polyacrylic acid having a weight average molecular weight M w of 4320 g/mol, which comprises just 45% of the sodium phosphite phosphorus as dialkyl phosphinate, 25% as monoalkyl phosphinate and 30% as inorganic salts.
EP-A 510 831 discloses a process for forming polymers from monoethylenically unsaturated monocarboxylic acids, monoethylenically unsaturated dicarboxylic acids and optionally further monomers, comprising no carboxyl group, in the presence of hypophosphorous acid as chain transfer agent. At least 40% of the phosphorus incorporated in the polymer is present as monoalkyl phosphinate and monoalkyl phosphonate at the end of the polymer chain. The copolymers are used inter alia as dispersants, scale inhibitors and laundry detergent additives.
EP-A 618 240 discloses a process for polymerization of monomers in water in the presence of a water-soluble initiator and hypophosphorous acid or a salt thereof. The process is carried out such that the polymer content at the end of the polymerization is at least 50% by weight. This method provides an increased incorporation of the hypophosphite phosphorus in the polymer. The hypophosphite phosphorus is present in the polymer in the form of dialkyl phosphinate, monoalkyl phosphinate and also monoalkyl phosphonate. No information is provided as to the distribution of the phosphorus. The copolymers are used inter alia as dispersants, scale inhibitors and laundry detergent additives.
EP-A 1 074 293 discloses phosphonate-terminated polyacrylic acid having a molecular weight M w of 2000 to 5800 g/mol as a dispersant for producing aqueous slurries of calcium carbonate, kaolin, clay, talc and metal oxides having a solids content of at least 60% by weight.
The problem addressed by the invention is that of providing low molecular weight polyacrylic acids having improved dispersing performance.
The problem is solved by a process for preparing aqueous solutions of acrylic acid polymers by polymerization of acrylic acid in feed operation with a free-radical initiator in the presence of hypophosphite in water as solvent, which process comprises
(i) initially charging water and optionally one or more ethylenically unsaturated comonomers,
(ii) continuously adding acrylic acid in acidic, unneutralized form, optionally one or more ethylenically unsaturated comonomers, aqueous free-radical initiator solution and aqueous hypophosphite solution,
(iii) adding a base to the aqueous solution on completion of the acrylic acid feed, wherein the comonomer content does not exceed 30% by weight, based on the total monomer content, wherein
the aqueous hypophosphite solution is added during a total feed time made up of three consecutive feed time spans Δt I , Δt II and Δt III , wherein the average feed rate in the second feed time span Δt II is greater than the average feed rates in the first and third feed time spans Δt I and Δt III .
Preferably, the first feed time span Δt I amounts to 30 to 70% of the total feed time.
Preferably, the second feed time span Δt II amounts to 5 to 25% and more particularly 5 to 15% of the total feed time.
Preferably, the third feed time span comprises two subsidiary feed time spans Δt IIIa and Δt IIIb , wherein the average feed rate during the first subsidiary feed time span Δt IIIa is not less than the average feed rate during the first feed time span Δt I and the average feed rate during the second subsidiary feed time span Δt IIIb is less than the average feed rate during the first feed time span Δt I .
The feed rate is the amount of substance per unit time, Δn/Δt.
The total feed time is generally in the range from 80 to 500 min and preferably in the range from 100 to 400 min.
The comonomers can be included in the initial reaction charge; partly initially charged and partly added as feed; or exclusively added as feed. When they are partly or wholly added as feed, they are generally added simultaneously with the acrylic acid.
In general, water is initially charged and heated to the reaction temperature of at least 75° C. and preferably in the range from 95 to 105° C.
In addition, an aqueous solution of phosphorous acid can be included in the initial charge as a corrosion inhibitor.
This is followed by the commencement of the continuous feeds of acrylic acid optionally of ethylenically unsaturated comonomer, initiator and chain transfer agent. Acrylic acid is added in unneutralized, acidic form. In general, the feeds are commenced simultaneously. Both peroxodisulfate as initiator and hypophosphite as chain transfer agent are added in the form of their aqueous solutions. Hypophosphite can be used in the form of hypophosphorous acid (phosphinic acid) or in the form of salts of hypophosphorous acid. It is particularly preferable to use hypophosphite as hypophosphorous acid or as sodium salt.
In general, acrylic acid is added at constant feed rate. When comonomers are used and at least partly added as feeds, then the feed rate of the comonomer feeds is generally likewise constant. The feed rate of the free-radical initiator solution is generally likewise constant.
Peroxodisulfate is the preferred free-radical initiator. Peroxodisulfate is generally used in the form of the sodium or ammonium salt. The content of a preferably used aqueous peroxodisulfate solution is in the range from 5% to 10% by weight. The hypophosphite content of the aqueous hypophosphite solution is preferably in the range from 35% to 70% by weight.
Preferably, peroxodisulfate is used in amounts of 0.5% to 10% by weight and preferably 0.8% to 5% by weight, based on the total amount of monomers (acrylic acid plus any comonomers).
Preferably, hypophosphite is used in amounts of 4% to 8% by weight and preferably 5% to 7% by weight, based on the total amount of monomers.
The duration of the initiator feed can be up to 50% longer than the duration of the acrylic acid feed. Preferably, the duration of the initiator feed is about 3 to 20% longer than the duration of the acrylic acid feed. The total duration of the chain transfer agent feed is preferably equal to the duration of the acrylic acid feed. In general, the total duration of the chain transfer agent feed is up to 20% shorter or longer than the duration of the acrylic acid feed.
The duration of the monomer feed or—when a comonomer is used—of the monomer feeds is in the range from 2 to 5 h for example. When all the feeds are commenced simultaneously, for example, the chain transfer agent feed ends from 10 to 30 min before the end of the monomer feed and the initiator feed ends from 10 to 30 min after the end of the monomer feed.
In general, a base is added to the aqueous solution on completion of the acrylic acid feed. This serves to at least partially neutralize the acrylic acid polymer formed. Partially neutralized is to be understood as meaning that only some of the carboxyl groups in the acrylic acid polymer are present in salt form. In general, sufficient base is added for the pH to subsequently be in the range from 3 to 8.5, preferably in the range from 4 to 8.5 and more particularly in the range from 4.0 to 5.5 (partially neutralized) or from 6.5 to 8.5 (fully neutralized). It is preferable to use aqueous sodium hydroxide solution as base. Besides aqueous sodium hydroxide solution, it is also possible to use ammonia or amines, for example triethanolamine. The degree of neutralization achieved for the polyacrylic acids obtained is between 15 and 100% and preferably between 30 and 100%. The neutralization is generally carried out over a comparatively long period ranging for example from ½ hour to 3 hours in order that the heat of neutralization may be efficiently removed.
In general, the polymerization is carried out under inert gas atmosphere. This generally provides acrylic acid polymers where the terminally bound phosphorus thereof is substantially (generally at least 90%) present in the form of phosphinate groups.
In a further version, an oxidation step is carried out on completion of the polymerization. The oxidation step serves to convert terminal phosphinate groups into terminal phosphonate groups. The oxidation is generally effected by treating the acrylic acid polymer with an oxidizing agent, preferably with aqueous hydrogen peroxide solution.
This provides aqueous solutions of acrylic acid polymers having a solids content of generally at least 30% by weight, preferably at least 35% by weight, more preferably in the range from 40% to 70% by weight and more particularly in the range from 40% to 55% by weight of polymer.
The acrylic acid polymers obtainable according to the present invention have a total phosphorus content of organically and possibly inorganically bound phosphorus, wherein
(a) a first portion of the phosphorus is present in the form of phosphinate groups bound within the polymer chain, (b) a second portion of the phosphorus is present in the form of phosphinate and/or phosphonate groups bound at the polymer chain end, (c) possibly a third portion of the phosphorus is present in the form of dissolved inorganic salts of phosphorus,
and generally at least 76% of the total phosphorus content is present in the form of phosphinate groups bound within the polymer chain.
Preferably at least 78% and more preferably at least 80% of the total phosphorus content is present in the form of phosphinate groups bound within the polymer chain. The feed method of the present invention provides a particularly high content of phosphorus bound within the polymer chain.
Generally at most 15% and preferably at most 12% of the phosphorus is present in the form of phosphinate and/or phosphonate groups bound at the polymer chain end. It is more preferable for 4 to 12% and especially 7 to 12% of the phosphorus to be present in the form of phosphinate and/or phosphonate groups bound at the polymer chain end.
Up to 15% of the phosphorus present in the aqueous solution of the acrylic acid polymers can be present in the form of inorganic phosphorus, more particularly in the form of hypophosphite and phosphite. Preferably from 2 to 12% and more preferably from 4 to 11% of total phosphorus is present in the form of inorganically bound phosphorus.
The ratio of phosphorus bound within the polymer chain to phosphorus bound at the chain end is at least 4:1. This ratio is preferably at least 5:1 to 10:1 and more particularly 6:1 to 9:1.
The weight average molecular weight of the acrylic acid polymer is generally in the range from 1000 to 20 000 g/mol, preferably in the range from 3500 to 12 000 g/mol, more preferably in the range from 3500 to 8000 g/mol, more particularly in the range from 3500 to 6500 g/mol and specifically in the range from 4000 to 6500 g/mol. The molecular weight can be specifically set within these ranges via the amount of chain transfer agent used.
The proportion of polymers having a molecular weight of <1000 g/mol is generally ≦10% by weight and preferably ≦5% by weight, based on total polymer.
The molecular weights were determined via GPC on buffered (to pH 7) aqueous solutions of the polymers using hydroxyethyl methacrylate copolymer network (HEMA) as stationary phase and sodium polyacrylate standards.
The M w /M n polydispersity index of the acrylic acid polymer is generally 5 2.5 and preferably in the range from 1.5 to 2.5, for example 2.
The K-values, determined by the Fikentscher method on a 1% by weight solution in completely ion-free water, are generally in the range from 10 to 50, preferably in the range from 15 to 35 and more preferably in the range from 20 to 30.
The acrylic acid polymer may comprise up to 30% by weight, preferably up to 20% by weight and more preferably up to 10% by weight, based on all ethylenically unsaturated monomers, of ethylenically unsaturated comonomers in copolymerized form. Examples of suitable ethylenically unsaturated comonomers are methacrylic acid, maleic acid, maleic anhydride, vinylsulfonic acid, allylsulfonic acid and AMPS and also salts thereof. Mixtures of these comonomers may also be present.
Particular preference is given to acrylic acid homopolymers without comonomer content.
The resulting aqueous solutions of the acrylic acid polymers can be used directly as dispersants.
The invention also provides for the use of the aqueous solutions of the acrylic acid polymers or the acrylic acid polymers themselves as dispersing auxiliaries for inorganic pigments and fillers, e.g., CaCO 3 , kaolin, talcum, TiO 2 , ZnO, ZrO 2 , Al 2 O 3 and MgO.
The slurries obtained therefrom are used as white pigments for graphics papers and paints, as deflocculants for the production of ceramic materials of construction, or else as fillers for thermoplastics. However, the acrylic acid polymers can also be used for other purposes, for example in laundry detergents, dishwasher detergents, technical/industrial cleaners, for water treatment or as oil field chemicals. If desired, they can be converted into powder form via various drying methods, e.g., spray drying, roll drying or paddle drying, before use.
A particularly preferred dispersions (slurry) for which the acrylic acid polymers of the present invention are used is ground calcium carbonate. The grinding is carried out continuously or batchwise in aqueous suspension. The calcium carbonate content of this suspension is generally ≧50% by weight, preferably ≧60% by weight and more preferably ≧70% by weight. Typically, the amount of polyacrylic acid used according to the present invention is in the range from 0.1% to 2% by weight and preferably in the range from 0.3% to 1.5% by weight, all based on the calcium carbonate in the suspension. After grinding, the particle size in these calcium carbonate slurries is preferably less than 2 μm for 95% of the particles and less than 1 μm for 75% of the particles. The calcium carbonate slurries obtained have excellent rheological properties and are still pumpable after several days' storage, as is evident from the viscosity courses in table 2.
The examples which follow illustrate the invention.
EXAMPLES
All molecular weights were determined via GPC. The GPC conditions used are as follows: 2 columns (Suprema Linear M) and a precolumn (Suprema Vorsaule), all of the brand Suprema-Gel (HEMA) from Polymer Standard Services (Mainz, Germany), was operated at 35° C. at a flow rate of 0.8 ml/min. The eluent used was the aqueous solution admixed with 0.15 M NaCl and 0.01 M NaN 3 and buffered with TRIS at pH 7. Calibration was done with a Na-PAA standard, the molecular weight distribution curve of which had been determined by SEC laser light dispersion coupling, using the calibration method of M. J. R. Cantow et al. (J. Polym. Sci., A-1, 5 (1967) 1391-1394), albeit without the concentration correction proposed therein. The samples were all adjusted to pH 7 with 50% by weight aqueous sodium hydroxide solution. A portion of the solution was diluted with completely ion free water to a solids content of 1.5 mg/mL and stirred for 12 hours. The samples were then filtered, and 100 μL was injected through a Sartorius Minisart RC 25 (0.2 μm).
Example 1
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous ammonium persulfate solution and 47.46 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of a distilled acrylic acid, 86.0 g of a 15% by weight aqueous ammonium peroxodisulfate solution and a first quantity of 130.14 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 2 hours, the ammonium peroxodisulfate within 2.25 hours and the sodium hypophosphite within 1 hour. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of the 15% by weight aqueous sodium hypophosphite solution was then added in stages. First 42.66 g within 10 minutes (4.26 g/minute), then 18.6 g within 5 minutes (3.74 g/minute), then 16 g within 5 minutes (3.20 g/minute), then 40 g within 15 minutes (2.66 g/minute), then 16 g within 10 minutes (1.60 g/minute), then 10.6 g within 10 minutes (1.06 g/minute) and 2.66 g within 5 minutes (0.52 g/minute). On completion of the ammonium peroxodisulfate feed, 310.86 g of a 50% aqueous sodium hydroxide solution were added at an internal temperature of 100° C. to part-neutralize the polyacrylic acid obtained. The polymer solution was then cooled down to room temperature. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 2
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous sodium persulfate solution and 47.46 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of a distilled acrylic acid, 86.0 g of a 15% by weight aqueous sodium peroxodisulfate solution and a first quantity of 130.14 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 2 hours, the sodium peroxodisulfate within 2.25 hours and the sodium hypophosphite within 1 hour. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of a 15% by weight aqueous sodium hypophosphite solution was then added in stages. First 42.66 g within 10 minutes (4.26 g/minute), then 18.6 g within 5 minutes (3.74 g/minute), then 16 g within 5 minutes (3.20 g/minute), then 40 g within 15 minutes (2.66 g/minute), then 16 g within 10 minutes (1.60 g/minute), then 10.6 g within 10 minutes (1.06 g/minute) and 2.66 g within 5 minutes (0.52 g/minute). On completion of the sodium peroxodisulfate feed, 310.86 g of a 50% by weight aqueous sodium hydroxide solution were added at an internal temperature of 100° C. to part-neutralize the polyacrylic acid. The polymer solution was then cooled down to room temperature. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 3
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous ammonium persulfate solution and 47.46 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of a distilled acrylic acid, 86.0 g of a 15% by weight aqueous ammonium peroxodisulfate solution and a first quantity of 130.14 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 5 hours, the ammonium peroxodisulfate within 5.25 hours and the sodium hypophosphite within 2.5 hours. On completion of the feed of the first quantity of sodium hypophosphite, a second quantity of the 15% by weight aqueous sodium hypophosphite solution was then added in stages. First 42.66 g within 25 minutes (1.71 g/minute), then 18.6 g within 12.5 minutes (1.49 g/minute), then 16 g within 12.5 minutes (1.28 g/minute), then 40 g within 37.5 minutes (1.07 g/minute), then 16 g within 25 minutes (0.64 g/minute), then 10.6 g within 25 minutes (0.42 g/minute) and finally 2.66 g within 12.5 minutes (0.21 g/minute). On completion of the ammonium peroxodisulfate feed, 310.86 g of a 50% by weight aqueous sodium hydroxide solution were added at an internal temperature of 100° C. to part-neutralize the polyacrylic acid formed. The polymer solution was then cooled down to room temperature. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 4
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous sodium persulfate solution and 47.46 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of a distilled acrylic acid, 86.0 g of a 15% by weight aqueous sodium peroxodisulfate solution and a first quantity of 130.14 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 5 hours, the sodium peroxodisulfate within 5.25 hours and the sodium hypophosphite within 2.5 hours. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of the 15% by weight aqueous sodium hypophosphite solution was added in stages. First 42.66 g within 25 minutes (1.71 g/minute), then 18.6 g within 12.5 minutes (1.49 g/minute), then 16 g within 12.5 minutes (1.28 g/minute), then 40 g within 37.5 minutes (1.07 g/minute), then 16 g within 25 minutes (0.64 g/minute), then 10.6 g within 25 minutes (0.42 g/minute) and 2.66 g within 12.5 minutes (0.21 g/minute). On completion of the ammonium peroxodisulfate feed, 310.86 g of a 50% by weight aqueous sodium hydroxide solution were added at an internal temperature of 100° C. to part-neutralize the polyacrylic acid formed. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 5
Comparative Example
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous ammonium persulfate solution and 47.46 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of a distilled acrylic acid, 86.0 g of a 15% by weight aqueous ammonium peroxodisulfate solution and 276.8 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 2 hours, the ammonium peroxodisulfate within 2.25 hours and the sodium hypophosphite within 2 hours. On completion of the ammonium peroxodisulfate feed, 310.86 g of a 50% by weight aqueous sodium hydroxide solution were added at an internal temperature of 100° C. to part-neutralize the polyacrylic acid formed. The polymer solution was then cooled down to room temperature. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 6
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 23.6 g of a 7% by weight aqueous sodium persulfate solution and 20.0 g of a 59% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 930.0 g of an 86% by weight aqueous solution of distilled acrylic acid, 184.3 g of a 7% by weight aqueous sodium peroxodisulfate solution and a first quantity of 55.0 g of a 59% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 5 hours, the sodium peroxodisulfate within 5.25 hours and the sodium hypophosphite within 2.5 hours. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of a 59% by weight aqueous sodium hypophosphite solution was then added in stages. First 18.0 g within 25 minutes (0.72 g/minute), then 8.0 g within 14 minutes (0.57 g/minute), then 6.0 g within 12 minutes (0.50 g/minute), then 17 g within 37 minutes (0.46 g/minute), then 7 g within 25 minutes (0.28 g/minute), then 4.0 g within 25 minutes (0.16 g/minute) and 1.0 g within 12 minutes (0.08 g/minute). On completion of the sodium peroxodisulfate feed, the polymer solution was cooled down to room temperature. 310.86 g of a 50% by weight aqueous sodium hydroxide solution were then added to set a degree of neutralization of 35%. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 7
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 23.6 g of a 7% by weight aqueous sodium persulfate solution and 8.0 g of a 59% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 930.0 g of an 86% by weight aqueous solution of distilled acrylic acid, 184.3 g of a 7% by weight aqueous sodium peroxodisulfate solution and a first quantity of 22.0 g of a 59% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 5 hours, the sodium peroxodisulfate within 5.25 hours and the sodium hypophosphite within 2.5 hours. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of a 59% by weight aqueous sodium hypophosphite solution was then added in stages. First 7.0 g within 25 minutes (0.28 g/minute), then 3.0 g within 14 minutes (0.21 g/minute), then 2.0 g within 12 minutes (0.17 g/minute), then 6 g within 37 minutes (0.16 g/minute), then 3 g within 25 minutes (0.12 g/minute), then 2.0 g within 25 minutes (0.08 g/minute) and 1.0 g within 12 minutes (0.08 g/minute). On completion of the sodium peroxodisulfate feed, the polymer solution was cooled down to room temperature. 310.86 g of a 50% by weight aqueous sodium hydroxide solution were then added to set a degree of neutralization of 35%. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 8
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 23.6 g of a 7% by weight aqueous sodium persulfate solution and 12.1 g of a 59% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 930.0 g of an 86% by weight aqueous solution of distilled acrylic acid, 184.3 g of a 7% by weight aqueous sodium peroxodisulfate solution and a first quantity of 33.0 g of a 59% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 5 hours, the sodium peroxodisulfate within 5.25 hours and the sodium hypophosphite within 2.5 hours. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of a 59% by weight aqueous sodium hypophosphite solution was then added in stages. First 11.0 g within 25 minutes (0.44 g/minute), then 5.0 g within 14 minutes (0.36 g/minute), then 4.0 g within 12 minutes (0.33 g/minute), then 10 g within 37 minutes (0.27 g/minute), then 4.0 g within 25 minutes (0.16 g/minute), then 3.0 g within 25 minutes (0.12 g/minute) and 1.0 g within 12 minutes (0.08 g/minute). On completion of the sodium peroxodisulfate feed, the polymer solution was cooled down to room temperature. 310.86 g of a 50% by weight aqueous sodium hydroxide solution were then added to set a degree of neutralization of 35%. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 9
A reactor was initially charged with 502.0 g of completely ion free water. The water was heated under nitrogen to 100° C. internal temperature. At this temperature, 11.0 g of a 15% by weight aqueous sodium persulfate solution and 47.5 g of a 15% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 1000 g of an 80% by weight aqueous solution of distilled acrylic acid, 86.0 g of a 15% by weight aqueous sodium peroxodisulfate solution and a first quantity of 130.0 g of a 15% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 2 hours, the sodium peroxodisulfate within 2.25 hours and the sodium hypophosphite within 1 hour. On completion of the feed of the first quantity of sodium hypophosphite solution, a second quantity of a 15% by weight aqueous sodium hypophosphite solution was then added in stages. First 43.0 g within 25 minutes (1.72 g/minute), then 19.0 g within 13 minutes (1.46 g/minute), then 16.0 g within 13 minutes (1.23 g/minute), then 40 g within 37 minutes (1.08 g/minute), then 16.0 g within 25 minutes (0.64 g/minute), then 11.0 g within 25 minutes (0.44 g/minute) and 2.0 g within 5 minutes (0.4 g/minute). On completion of the sodium peroxodisulfate feed, the polymer solution was cooled down to room temperature. 310.86 g of a 50% by weight aqueous sodium hydroxide solution were then added to set a degree of neutralization of 35%. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
Example 10
Comparative Example
A reactor was initially charged with 540.0 g of completely ion free water together with 9.0 g of a 0.15% iron(II) sulfate heptahydrate. This initial charge was heated under nitrogen to 90° C. internal temperature. At this temperature, 77.2 g of a 35% by weight aqueous sodium hypophosphite solution were added simultaneously within 1 minute. Then, 900 g of a distilled acrylic acid, 59.2 g of a 15.2% by weight aqueous sodium peroxodisulfate solution and 77.2 g of a 20.6% by weight aqueous sodium hypophosphite solution were metered in separately and concurrently under agitation. The acrylic acid was added within 2 hours, the sodium peroxodisulfate within 2 hours and the sodium hypophosphite within 1.6 hours. On completion of the sodium peroxodisulfate feed the polymer solution was subsequently stirred at 90° C. for 30 minutes and then cooled down to room temperature. The pH, the molecular weights M n and M w , the solids content and the residual acrylic acid content were determined and the solution was visually inspected.
The analytical data of the acrylic acid polymers obtained are summarized below in table 1.
TABLE 1
Oligomer
Solids
content
content
<1000
P %
P %
P %
Example
[%] a
K value b
pH (tq)
Mw c
PDI c
g/mol
internal d
external d
inorg d
1
42.5
24.8
4.3
5080
2.1
4.7
79.6
11.3
9.2
2
41.5
24.9
4.3
4990
2.1
4.9
81.6
6.9
10.5
3
42.1
24.1
4.3
4820
2.0
5.2
85.8
6.4
7.8
4
43.6
23.2
4.5
4960
2.1
5.4
86.7
5.6
7.7
5
41.6
26.0
4.3
5490
2.1
4.4
65.1
13.0
20.5
6
46.4
16.6
4.2
3040
1.6
6.4
86.3
8.1
5.6
7
45.8
30.3
4.2
8020
2.4
2.5
80.8
11.7
7.5
8
46.1
24.0
4.3
4990
1.9
3.4
83.9
10.2
5.9
9
43.5
23.7
4.3
5080
2.0
3.8
86.7
5.6
7.7
10
58.6
23.5
1.8
4610
1.8
3.7
75.9
18.8
5.3
a ISO 3251, (0.25 g, 150° C., 2 h)
b determined by Fikentscher method with 1% solution in completely ion free water
c determined by gel permeation chromatography
d determined with 31 P{ 1 H} and 31 P NMR
Performance Tests
Use of Acrylic Acid Polymers as Dispersants
The polyacrylic acid solutions obtained were tested for their usefulness as dispersants for producing slurries. For this, calcium carbonate was in each case ground using a Dispermat. For this, in each case, 300 g of calcium carbonate (Hydrocarb OG from Omya) and 600 g of ceramic beads were mixed and initially charged to a 500 ml double-wall vessel filled with tap water. Then, 100 g of a 3% by weight aqueous solution of the in-test polyacrylic acid was added after adjustment to pH 5.0. The grinding was done using a grinding assembly of the type Dispermat AE-C (from VMA-Getzmann) with a cross-beam stirrer at 1200 rpm. As soon as 70% of the pigment had a particle size (PSD) of less than 1 μm, the grinding operation was terminated (about 70 min, LS 13320 particle measuring instrument from Beckman Coulter). After grinding, the slurry was filtered through a 780 μm filter using a porcelain suction filter to remove the ceramic beads, and the solids content of the slurry was adjusted to 77%. The viscosity of the slurry was determined at once, after 24 h and after 168 h using a Brookfield DV II viscometer (using spindle No. 3).
The results of the dispersing tests are summarized in table 2.
TABLE 2
Dynamic viscosity [mPas]
Slurry
Particle size
at 100 rpm
solids
distribution
after
after
After
after
content
Example
<2 μm
<1 μm
1 h
24 h
96 h
168 h
[%]
1
99.1
74.0
527
930
1750
2450
77.0
2
98.9
72.9
620
1870
2220
3341
77.0
3
97.6
72.6
687
1710
2747
3419
77.0
4
97.2
71.1
619
1620
2357
3289
77.0
5
98.9
72.5
820
2540
3960
5270
77.0
6
99.5
74.0
2034
4055
>6000
>6000
77.0
7
99.0
74.0
835
1902
3209
4050
77.0
8
99.1
74.6
524
949
1974
2567
77.0
9
98.9
75.0
628
1448
2280
2890
77.0
10
98.9
72.4
1284
3011
4380
5645
77.0
|
An aqueous solution of an acrylic acid polymer which contains bound phosphonite groups is provided. The acrylic acid polymer is prepared by a feed operation polymerization which results in the formation of phosphinite groups bound within the acrylic acid polymer chain. The dried acrylic acid polymer is also provided. Dispersions of inorganic pigments prepared in the presence of the acrylic acid polymer or the aqueous solution of the acrylic acid polymer are also provided.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of prior application U.S. Ser. No. 09/371,781 filed on Aug. 10, 1999 now U.S. Pat. No. 6,721,410 which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates generally to the field of telecommunications, and more particularly to casual collaborative conferencing.
B. Description of the Related Art
The World Wide Web (WWW), one type of service provided through the Internet, allows a user to access a universe of information which combines text, audio, graphics and animation within a hypermedia document. Links are contained within a WWW document which allow simple and rapid access to related documents. The WWW was developed to provide researchers with a system that would enable them to quickly access all types of information with a common interface, removing the necessity to execute a variety of numerous steps to access the information. During 1991, the WWW was released for general usage with access to hypertext and UseNet news articles. Interfaces to WAIS, anonymous FTP, Telnet and Gopher were added. By the end of 1993, WWW browsers with easy to use interfaces had been developed for many different computer systems.
UseNet is a network of news groups on thousands of different topics which allow the on-line discussion through the posting of individual messages (articles) which can be read by participants. An article is similar to an e-mail message, having a header, message body and signature.
Internet Relay Chat (IRC) is an example of a program that facilitates Web chat. “Chatting” is the term used for the network equivalent of the old telephone party line. RC is accessed through an Internet connection. This technology permits the user to chat with users from all over the world about hundreds of different subjects at any time. In a way, it is as if the UseNet newsgroups were a live discussion group rather than postings.
The word “chat” may be somewhat misleading, because persons participating in a chat session are not necessarily speaking, but they are typing and reading text messages that chat participants write. Moreover, if the information communicated is not only in text form, but is real-time audio and video, chat rooms are better described by the term virtual space rooms. Once a person enters a chat room, which is really just a web page, that person can choose to only read the exchanges, known as lurking, or the person can join in and post messages.
Many chat rooms focus the conversation on specific topics, such as health, politics, and football. In that way, people with similar interests can find one another.
The first step for a person interested in joining a chat session, is to locate a chat room that interests the person. Once the person is on the web site (leading to the chat room), the interested person will usually be asked to register. For privacy purposes, people do not register using their real name, but instead people make up a name.
Once the person is equipped with a registration name, the person clicks a button and follows the instructions on the web site to choose a chat room, depending on the interests of the person. Joining a chat room is like walking into a room full of people talking to each other, sometimes with several conversations going on at once. Once inside the chat room, the person will probably find himself or herself in the middle of a conversation. There is no need to jump into the conversation. It is not uncommon for chat rooms to have many more lurkers than participants. As the interaction continues, new postings appear on the computer screen. When the person decides to join the conversation, all it takes is to type a message in a blank box in the screen and click a Talk button (or hit the Enter or Return key on the keyboard). Soon the message will be posted in the chat room and people may respond. In addition to chatting on a chat room where the text is broadcast to everyone on that chat room, there are ways to enter into a private chat.
A number of Internet phone software products offer voice capabilities in real time over the Internet. Internet phoneware vendors typically provide their own directory servers, organized by topic as well as by name. Voice quality varies from moment to moment. Such variations are due to the processing delay that results from encoding and decoding the conversation as well as the inherent delay of the Internet, which varies according to the amount of traffic at any given time and the route through which the signal must travel.
The Web chat is, however, only one level of an area of technology known as collaborative conferencing. Collaborative conferencing is the ability for two or more individuals to work together in real-time, in a coordinated manner over time and spice by using computers. Collaborative conferencing is not limited to a live text exchange, but includes data conferencing/shared whiteboard applications, group interactive document editing, and audio and video multi-point conferencing among others.
The technique of Internet chat has the disadvantage that it is limited in the choices that individuals can make respecting whom they want to establish communication with. Namely, they have to join a chat room that has a specific discussion topic, and can only pick people in that chat room with whom to engage in a private chat. To solve this problem, a solution has been proposed and implemented, in which matches between different individuals connected to the WWW are created. This requires the inconvenient step of requesting information to the user, so as to create a user profile, and thus, perform matches based on those profiles.
Therefore, there is a need in the art for a system that offers more flexibility to individuals to choose other individuals with whom they want to engage in a conversation, the conversation not being limited to a conventional Internet chat (text).
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to meet the foregoing needs by providing systems and methods that efficiently enable real-time communication among two or more individuals separated in space.
Specifically, a method for meeting the foregoing needs is disclosed. The method includes the steps of determining that a first individual is likely to be interested in communicating with a second individual via a first communications link; retrieving information via the first communications link about one or more additional individuals from electronic memory means associated with the second individual; and establishing communication with at least one of the additional individuals based on the retrieved information.
Both the foregoing general description and the following detailed description provide examples and explanations only. They do not restrict the claimed invention.
DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, explain the advantages and principles of the invention. In the drawings,
FIG. 1 is a block diagram of a collaborative conferencing system;
FIG. 2 is a block diagram of a computer system associated with user A in FIG. 1 ;
FIG. 3 is an example of an user's personal directory according to the present invention;
FIG. 4 is a flowchart describing the steps to establish real-time communication according to the present invention; and
FIG. 5 is a diagram showing a second mode of operation of the computer system in FIG. 2 .
DETAILED DESCRIPTION
Reference will now be made to preferred embodiments of this invention, examples of which are shown in the accompanying drawings and will be obvious from the description of the invention. In the drawings, the same reference numbers represent the same or similar elements in the different drawings whenever possible.
Systems and methods consistent with the present invention perform collaborative conferencing by using recursive identification of individuals. For purposes of the following description, the systems and methods consistent with the present invention are mainly described with respect to Internet chat. The description should be understood to apply to other levels or modes of operation in a collaborative conferencing system, such as a casual collaborative conversation with persons in a virtual space room.
FIG. 1 shows a general collaborative conferencing (system 100 . The system includes communication means associated with users A-F ( 10 , 12 and 16 - 19 ), a Wide Area Network (WAN) 14 , and a chat server 22 . The WAN 14 is any network that is capable of transferring data at speeds fast enough as to support collaborative conferencing. An example of a WAN is the Internet. The chat server 22 is a computer connected to the WAN 14 that offers a chat service. That is, the chat server 22 runs software that enables the creation of a chat room. The users A-F can enter the chat room if connected to the chat server 22 . As mentioned above, a chat room is nothing more that a web page, which in this case is supported by the chat server 22 . By contrast, supporting a virtual space room might require equipment other than a single server. Support for the virtual space room can be offered by several servers (not shown) that are part of the WAN 14 .
In the system 100 , user A determines that user B is a person that is likely to be interesting enough so as to get involved in a casual collaborative conversation with that person. That is, if user A believes that he or she shares common interests with user B, user A will engage in collaborative conferencing with user B. This determination is made after obtaining information about user B. The information is obtained by communicating with user B. The manner in which user A communicates with user B in order to determine whether he or she is likely to be interested in communicating with user B (possibly via some other communication means or links) includes, but is not limited to, telephonic conversations, e-mail, voice mail, real-time video, and real-time text.
Once user A determines he or she is likely to be interested in communicating with user B, user A targets or spots user B when user B enters a chat room or a virtual space room. User A will see on his computer screen ( 208 in FIG. 2 ) either the name or an image of user B whenever user B is “on-line”. Each user in the system 100 has a personal directory 20 containing the names of other people with collaborative conferencing capability.
Unlike conventional methods of matchmaking in a chat room context, user A does not rely on a computer program to pick interesting persons for him or her. Instead, user A relies on user B's personal directory 20 as a starting point to find more interesting persons. User A accesses some of the information contained in directory 20 about other users with collaborative conferencing capability, with whom user B communicates. This technique is called recursive identification of individuals. The information that user A can access is limited according to permissions assigned to each record in the directory by user B.
FIG. 3 shows an example of different permissions designated by user B. The directory 20 contains individual records 300 - 304 that correspond to individuals with collaborative conferencing capability. The list of users ( 300 - 304 ) is by no means extensive and is not representative of all of the possible users that could be included in the directory 20 . Records 300 - 304 contain user information that includes, but is not limited to, users' e-mail address, users' names and virtual space room login names, picture id's, etc.
There are different levels of permissions that the user B can assign to the users records ( 300 - 304 ) in the directory 20 . Because any other user of the system in the present invention can get access to some information, user 12 assigns access permissions to records 300 - 304 . These permissions define how much information can be accessed by the other users via their respective communications means ( 10 and 16 - 19 in FIG. 1 ).
One level of access corresponds to the type of service that is used within the system. In FIG. 3 , the record 300 , corresponding to user C can be accessed by the entire public that communicates with user B via Web chat (e.g., a chat server 22 ). The term “public” refers to all of the persons with collaborative conferencing capabilities. On the other hand, when another level in collaborative conferencing is in use, namely, video conferencing, only users A and D can access record information 300 about user C from user B's directory 20 .
Other levels of permissions include, but are not limited to, giving the public access to the entire directory 20 , giving specific persons access to the entire directory 20 , giving the public access to information contained in some of the records 300 - 304 , and giving specific persons access to information contained in some of the records 300 - 304 .
The directory 20 can be created by user B manually. That is, user B can gather a list of names of individuals that he or she communicates with, and enters that list into the directory 20 . In the present invention, an alternative to manually creating the directory is to have the software that enables collaborative conferencing create the directory 20 for the user. The software has a routine that monitors the communication between user B and other users (e.g., C-F) and that adds to the directory 20 information about the users that communicate with user B. As an option, the software can sort the information in the directory 20 , according to the frequency of the communications between user B and the individuals named in the directory 20 . Moreover, another option consists of automatically deleting information from the directory 20 , when the software determines that persons that do not communicate frequently with user B, have not actually communicated with user B for specified period of time. For example, the software could look at the sorted directory 20 , and determine whether the individual whose information is at the bottom of the directory (less frequency) has communicated with user B in the past two months. If the person at the bottom has not done so, that person's information is deleted from the directory 20 . The period of two months is only an example of a parameter that can be adjusted according to the directory's owner preferences.
FIG. 2 shows communication means 10 for enabling communication between user A and other users (e.g., users B-F) of the system 100 , and that corresponds to user A in this particular example. The communication means 10 includes a computer system 202 with a keyboard 206 and a screen 208 ; and a speaker 204 , camera 212 , and microphone 210 connected to the computer 202 . The computer 202 runs software that displays on screen 208 a representation of other users 220 - 222 present (on-line) in a virtual space room. The ability of communicating with these other parties in real-time via the computer system 202 is what makes the system a collaborative conferencing system.
The computer 202 only displays an image of those users that have been determined to be of interest to user A 10 . As seen on FIG. 2 , user A has determined that he or she is likely to be interested in communicating with users C, E and F. The representation of users C, E and F in the computer screen is denominated by numerals 220 - 222 , and it includes image information as well as other personal information about the users. User A uses different means to communicate with any of the users in the virtual space room. These means include, but are not limited to, voice, interactive text (chat), e-mail, and video.
The speaker 204 is used for listening to voice messages sent by the users in the virtual space room. On the other hand, the microphone 210 is used to send voice messages to users in the virtual space room. These voice messages are either voice mail messages, stored either locally in the computer 202 or in some other recording means, or real-time voice messages (i.e., real-time telephony).
The camera 212 is used to capture an image of user A, which is presumably displayed in the computer screen associated with other users participating in the virtual space room. The camera 212 is turned off when user A does not desire to transmit an 1 image of herself/himself. It is possible to have a participant in the virtual space room that does not want his or her image displayed. For example, a chat window 224 displays interactive text communications between user B and user A. As seen from the display, an image of user B is not shown in the screen 208 . The chat window 224 is used by any of the users in the virtual space room, and its use is limited to displaying text messages from all of the parties, as it would for a conventional chat room.
When user A decides to communicate via interactive text, he or she needs to type the message on the keyboard 206 . The user can edit the entered text which is displayed on the window 228 . After the changes have been entered, the text is displayed on the chat window 224 when user A hits the button 226 displayed on the screen 208 .
By comparing FIG. 2 and FIG. 3 , one notices that the image representations 220 - 222 displayed on screen 208 of user A's computer system 202 match the permissions associated to users C, E and F ( 300 , 302 and 303 in FIG. 3 ). As discussed above, user A has determined that user B is likely to be an interesting person. This is evidenced by the interactive text exchange between user A and user B, shown in windows 224 and 228 of FIG. 2 . It is also evident from FIG. 2 , that user A could have accessed the directory 20 in order to access information about users C, E and F. Thus, user A determined that users C, E and F are also likely to be interesting. User A could have also determined that user D is likely to be an interesting person, even though user D is not displayed on screen 208 . Only users that are on-line are displayed on the screen 208 .
FIG. 4 shows a method for performing collaborative conferencing in accordance with the present invention. In step 401 a first user determines which persons are likely to be interesting. As discussed previously, this determination can be done for a single person, and then the determination of additional persons likely to be interesting can be expanded by looking at the directory of the first persons determined to be likely interesting. In step 402 , the first user accesses the personal directory of one of the likely interesting persons. This step is not limited to the first person that was determined to be likely interesting. Once a list of likely interesting persons have been put together by the first user, he or she can go into the directory of any of the individuals in that list.
After the first user has determined likely interesting persons and has accessed the directory of a first likely interesting person, the first user establishes communication with the persons who are determined to be likely interesting. This communication takes place in a virtual space room context.
FIG. 5 shows is alternative embodiment of the present invention. The software running on the computer 202 allows persons in a virtual space room to be separated in subgroups. These subgroups are displayed 501 - 503 on the computer screen 208 . Persons in Group I 501 , cannot communicate with persons outside Group I 501 (Group II 502 , Group III 503 ). Assuming that user A belongs to Group I 501 , user A can still see in the computer screen 208 who is in the other groups. If user A wants to communicate with individuals from the other groups, user A must change groups in order to accomplish the desired communication. For example, if user A is in Group I 501 , and notices that user B (a person that is likely to be interesting) is in Group II 502 , user A would have to enter Group II 502 in order to communicate with user B. Once user A transfers to Group II 502 , an image representation of user A would appear in the area of the computer screen that corresponds to Group II 502 .
The foregoing description of preferred embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The scope of the invention is defined by the claims and their equivalents.
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A method for real-time communication among two or more individuals separated in space. The method includes the steps of determining that a first individual is likely to be interested in communicating with a second individual via a first communications link; retrieving information via the first communications link about one or more additional individuals from electronic memory means associated with the second individual; and establishing communication with at least one of the additional individuals based on the retrieved information.
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